CN117368900A

CN117368900A - Signal processing device and method of radar system and related equipment

Info

Publication number: CN117368900A
Application number: CN202210770951.1A
Authority: CN
Inventors: 许丞; 丁云; 赵毅强
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2024-01-09

Abstract

The invention discloses a signal processing device, a signal processing method, a signal processing device and related equipment of a radar system, and belongs to the technical field of radars. The signal processing device includes: a detection unit and a processing unit; the detection unit is used for converting a first echo signal into a first electric signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, and converting a second echo signal into a second electric signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by the radar system in the same direction and are transmitted by two times in sequence; the processing unit is used for determining whether the target object moves or not based on the first flight time corresponding to the first electric signal and the second flight time corresponding to the second electric signal, and determining a detection result of the target object based on the second flight time when the target object is determined to move. It is advantageous to reduce the data processing amount of the receiving device of the radar system.

Description

Signal processing device and method of radar system and related equipment

Technical Field

The present disclosure relates to the field of radar technologies, and in particular, to a signal processing apparatus, a signal processing method, and a related device for a radar system.

Background

A radar system is an electronic device that detects a target object using electromagnetic waves. In general, radar systems include a transmitting device and a receiving device. The transmitting device transmits the transmitting signal to detect the target object, the receiving device receives the echo signal reflected by the target object, and relevant information of the target object, such as distance and the like, is determined based on the received echo signal.

In the related art, the receiving apparatus includes a detecting unit and a processing unit. The detection unit is used for converting the echo signals into electric signals; the processing unit is used for determining the corresponding time of flight (tof) of the electric signal, and then determining the distance of the target object according to the time of flight.

Each time the radar system transmits a transmit signal, the receiving device may receive one or more echo signals. The receiving device needs to process all echo signals, the data processing amount is large, and the computing processing capacity of the receiving device is high.

Disclosure of Invention

The application provides a signal processing device, a signal processing method and related equipment of a radar system, which are beneficial to reducing the data processing capacity of a receiving device of a radar receiving system and reducing the requirement on the computing processing capacity of the receiving device.

In a first aspect, a signal processing apparatus of a radar system is provided. The signal processing device includes: a detection unit and a processing unit; the detection unit is used for converting a first echo signal into a first electric signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, and converting a second echo signal into a second electric signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by the radar system in the same direction and are transmitted by two times in sequence; the processing unit is used for determining whether the target object moves or not based on a first flight time corresponding to the first electric signal and a second flight time corresponding to the second electric signal, and determining a detection result of the target object based on the second flight time when the target object moves.

In the application, whether the target object moves is determined based on the first flight time corresponding to the first electric signal and the second flight time corresponding to the second electric signal, and then the detection result of the target object is determined based on the second flight time under the condition that the target object is determined to move. I.e. only the detection result of a moving target object is of interest, whereas for an object that is not moving, no further processing of the electrical signal resulting from the echo signal conversion is necessary to determine the detection result. Compared with the detection result of determining the target object according to the corresponding flight time for each echo signal, the data volume required to be processed by the processing unit is reduced, and the requirement on the calculation processing capacity of the processing unit is reduced.

In one possible embodiment, the processing unit determines whether the target object is moving based on a difference between the first time of flight and the second time of flight.

In another possible embodiment, the processing unit determines whether the target object is moving based on a difference between the first characteristic value and the second characteristic value. Here, the first characteristic value is used to indicate a first time of flight and the second characteristic value is used to indicate a second time of flight.

In this embodiment, the processing unit includes: an electrical signal generation subunit, a delay storage subunit, and a processing subunit. The electric signal generating subunit is configured to generate a reference electric signal whose characteristic value changes monotonically with time in response to a reset signal, and output, based on the reference electric signal, a first characteristic value corresponding to the first electric signal and a second characteristic value corresponding to the second electric signal, where the first characteristic value is used to indicate the first time of flight, and the second characteristic value is used to indicate the second time of flight, and the reset signal is synchronous with driving signals of the first emission signal and the second emission signal. And the delay storage subunit is used for carrying out delay output on the first characteristic value. The processing subunit is used for determining whether the target object moves or not based on the second characteristic value output by the electric signal generating subunit and the first characteristic value output by the delay storage subunit; and determining a detection result of the target object based on the second characteristic value when it is determined that the target object moves.

Most of the circuits in the processing unit are analog circuits, such as part of the circuits in the processing subunit, the electric signal generating subunit and the delay storage subunit, and the second flight time is determined by the form of the analog circuits, so that an ADC (analog to digital converter) is not needed, and the cost is reduced.

Illustratively, the characteristic values include, but are not limited to, voltage values, current values, frequency values, and the like.

In some examples, the electrical signal generation subunit includes: a current source, a first switching device, an energy storage element, a second switching device and a third switching device. The input end of the current source is connected with a power supply, the output end of the current source is connected with one end of the first switching device, the other end of the first switching device is connected with one end of the energy storage element, and the other end of the energy storage element is grounded; the current source is used for charging the energy storage element when the first switching device is closed so as to generate a reference electric signal with the voltage value linearly increasing along with time; the second switching device is connected with the energy storage element in parallel, and is used for being closed under the action of the reset signal so as to zero the characteristic value of the reference electric signal; the input end of the third switching device is connected with one end of the energy storage element, the output end of the third switching device is respectively connected with the delay storage subunit and the processing subunit, and the third switching device is used for outputting the second characteristic value to the delay storage subunit and the processing subunit.

The first switching device and the second switching device are used for controlling the charge and discharge of the energy storage element, so that a reference electric signal with the voltage value being reset to zero and then being linearly increased along with time when a reset signal arrives is generated, and the circuit structure is simple. In addition, the characteristic value of the reference electric signal linearly increases along with time, so that the subsequent method for converting the flight time based on the characteristic value of the reference electric signal is simple, and the calculated amount is small.

In some examples, the processing subunit includes a first comparator, a fourth switching device, and a processing device. One input end of the first comparator is connected with the electric signal generation subunit, the other input end of the first comparator is connected with the output end of the delay storage subunit, and the difference value between the first characteristic value and the second characteristic value is used for determining whether the target object moves or not. The control end of the fourth switching device is connected with the output end of the first comparator, the input end of the fourth switching device is connected with the electric signal generation subunit, and the fourth switching device is used for outputting the second characteristic value when the absolute value of the difference value is larger than a characteristic value threshold value. The processing device is connected with the output end of the fourth switching device and is used for determining the detection result of the target object based on the second characteristic value.

In some examples, to reduce interference of noise signals, the processing unit further comprises a threshold decision subunit connected to the detection unit and the electrical signal generation subunit, respectively. The threshold value judging subunit is used for outputting a trigger signal when the amplitude value of the second electric signal is larger than an amplitude value threshold value. The electric signal generation subunit is used for outputting the second characteristic value according to the trigger signal.

Optionally, the detection result of the target object further comprises the reflectivity of the target object. The signal processing device further comprises a sampling unit, a sampling unit and a sampling unit, wherein the sampling unit is used for sampling the amplitude of the second electric signal when the target object is determined to move, so as to obtain a sampling result; the processing unit is further configured to determine a reflectivity of the target object based on the sampling result.

In some examples, the sampling unit includes: a sample-and-hold, a fifth switching device and an analog-to-digital converter (analog to digital converter, ADC). The sample-and-hold unit is used for sampling and holding the amplitude of the second electric signal and outputting a sample-and-hold signal. The control end of the fifth switching device is connected with the processing unit, the input end of the fifth switching device is connected with the output end of the sampling holder, and the fifth switching device is used for being conducted under the action of a control signal output by the processing unit. The ADC is connected with the output end of the fifth switching device and is used for sampling the sampling hold signal when the fifth switching device is conducted, so that the sampling result is obtained.

And when the amplitude of the second electric signal is larger than the amplitude threshold value, the amplitude of the second electric signal is sampled and held through the sampling holder until one detection period is finished or until the next electric signal arrives. Therefore, the ADC only needs to sample the sample hold signal once in one detection period, so that a sampling result can be obtained, and the sampling rate of the ADC is low. Since the price of an ADC is typically positively correlated with the sampling rate, the higher the price of the ADC. Therefore, the use of an ADC with a low sampling rate is advantageous in reducing the cost of the signal processing apparatus.

In a second aspect, a signal processing method of a radar system is provided. The method comprises the following steps: obtaining a first electric signal and a second electric signal, wherein the first electric signal is obtained by converting a first echo signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, the second electric signal is obtained by converting a second echo signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are two transmitting signals which are transmitted by the radar system to the same direction in sequence; determining whether the target object moves based on a first flight time corresponding to the first electrical signal and a second flight time corresponding to the second electrical signal; and determining a detection result of the target object based on the second flight time when the target object is determined to move.

In some examples, the determining whether the target object is moving based on the first time of flight corresponding to the first electrical signal and the second time of flight corresponding to the second electrical signal includes: determining a first characteristic value corresponding to the first electric signal and a second characteristic value corresponding to the second electric signal, wherein the first characteristic value is used for indicating the first flight time, the second characteristic value is used for indicating the second flight time, and the first characteristic value and the second characteristic value are determined based on a corresponding relation between the characteristic value and time, and in the corresponding relation, the characteristic value monotonically changes along with time; based on the first and second eigenvalues, it is determined whether the target object is moving.

In some examples, the detection result of the target object includes a distance of the target object; the determining the detection result of the target object based on the second flight time corresponding to the second electric signal includes: determining the second flight time corresponding to the second characteristic value according to the change rate of the characteristic value in the corresponding relation; and determining the distance of the target object according to the second flight time.

In some examples, the determining the second characteristic value corresponding to the second electrical signal includes: and when the amplitude of the second electric signal is larger than an amplitude threshold value, determining a characteristic value corresponding to the receiving time of the second echo signal as the second characteristic value.

In some examples, the detection result of the target object includes a reflectivity of the target object; the method further comprises the steps of: when the target object is determined to move, sampling the amplitude of the second electric signal to obtain a sampling result; and determining the reflectivity of the target object based on the sampling result.

In a third aspect, a computer device is provided, the computer device comprising a processor and a memory; the memory is for storing a software program, and the processor is for causing the computer device to carry out the method of any one of the possible embodiments of the second aspect by executing the software program stored in the memory.

In a fourth aspect, there is provided a computer readable storage medium storing computer instructions that, when executed by a computer device, cause the computer device to perform the method of any one of the possible embodiments of the second aspect.

In a fifth aspect, there is provided a computer program product comprising instructions which, when run on a computer device, cause the computer device to perform the method of any one of the possible embodiments of the second aspect described above.

In a sixth aspect, there is provided a chip comprising a processor for calling from a memory and executing instructions stored in said memory, to cause a computer device on which said chip is mounted to perform the method of any one of the possible implementations of the second aspect described above.

In a seventh aspect, there is provided another chip comprising: the input interface, the output interface, the processor and the memory are connected through an internal connection path, the processor is used for executing the codes in the memory, and when the codes are executed, the processor is used for executing the method in any possible implementation mode of the second aspect.

In an eighth aspect, a radar system is provided. The radar system comprises a transmitting device and a receiving device. The transmitting device is used for transmitting a first transmitting signal and a second transmitting signal, and the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by the radar system twice in sequence in the same direction. The receiving means is for receiving a first echo signal and a second echo signal, the first echo signal being obtained by reflection of the first transmission signal by a target object, the second echo signal being obtained by reflection of the second transmission signal by a target object, and the receiving means comprises the signal processing means of any one of the possible implementation manners of the first aspect.

Drawings

Fig. 1 is a schematic structural diagram of a radar system according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a signal processing device according to an embodiment of the present application;

fig. 3 is a schematic circuit diagram of a processing unit according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of another signal processing device according to an embodiment of the present application;

FIG. 5 is a signal timing diagram of the signal processing apparatus shown in FIG. 4;

FIG. 6 is a flow chart of a signal processing method according to an exemplary embodiment of the present application;

fig. 7 is a schematic structural diagram of another signal processing device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a computer device according to an embodiment of the present application.

Detailed Description

For a better understanding of the embodiments of the present application, the structure and the working principle of the radar system provided in the embodiments of the present application are first described below.

Radar systems typically include a transmitting device and a receiving device. The transmitting device is used for transmitting a transmitting signal (also called a detecting signal). The receiving device is used for receiving a signal (also called an echo signal) of the transmitted signal reflected by the target object, and processing the echo signal to obtain a detection result of the target object, such as distance, azimuth, altitude, speed, gesture and the like.

In some examples, the radar system is a lidar system and the corresponding transmit signal is a laser signal. In other examples, the radar system is a millimeter wave radar system and the corresponding transmitted signal is an electromagnetic wave signal.

The following describes the structure of the radar system in detail, taking the lidar system as an example.

Fig. 1 is a schematic structural diagram of a radar system according to an embodiment of the present application. As shown in fig. 1, the radar system 1 includes a transmitting device 10 and a receiving device 20.

The transmitting device 10 includes a laser, a laser driving module, and a transmitting light path. The laser generates pulse laser under the drive of the laser driving module and emits the pulse laser through an emission light path, namely an emission signal is formed. The laser may be, for example, a solid state laser, a semiconductor laser, a gas laser, an infrared laser, an X-ray laser, a chemical laser, an excimer laser, a dye laser, or the like, which is not limited in this application, and an appropriate laser may be selected according to actual needs. Here, the emission light route is constituted by one or more optical elements. Optical elements such as lenses, mirrors, optical fibers, and the like.

The receiving means comprise a receiving module 21 and signal processing means 22. The receiving module 21 includes a receiving optical path, and the transmitting signal transmitted by the transmitting device 10 is reflected by the target object a to form an echo signal, and the echo signal reaches the signal processing device 22 through the receiving optical path. Here, the reception light route is constituted by one or more optical elements. Optical elements such as lenses, mirrors, optical fibers, and the like. The signal processing device 22 is configured to determine information such as a distance and a direction of the target object, that is, determine a detection result of the target object, based on the echo signal received by the receiving module 21.

In embodiments of the present application, the transmitting device 10 may have one or more transmitting channels. The emission channels are defined by emission light paths, each emission channel being for emitting a beam of laser light, which may be generated by one or more lasers. The receiving device 20 may have one or more receiving channels. The receiving channel is defined by a receiving optical path. The transmit channels of the transmitting device 10 and the receive channels of the receiving device 20 may be in a one-to-one correspondence, each receive channel being adapted to receive an echo signal formed by a transmit signal transmitted by a corresponding one of the transmit channels.

In an embodiment of the present application, the transmission signal is a pulse signal, and one transmission signal includes at least one pulse. Each transmit signal may correspond to one or more echo signals. For example, a transmit channel may transmit a transmit signal and a corresponding receive channel may receive one or more echo signals.

In some examples, the radar system further comprises scanning means (not shown) connected to the transmitting means and the receiving means, respectively, for controlling the direction in which the transmitting means transmits the transmission signal and the direction in which the receiving means receives the echo signal. In these examples, the transmission directions (i.e., the directions in which the transmission signals are transmitted) of the same transmission channel at different times are different. Accordingly, the reception directions (directions in which echo signals are received) of the same reception channel at different times are also different. Alternatively, the scanning device includes, but is not limited to, micro-Electro-Mechanical System (MEMS) Micro-mirrors, turning mirrors, vibrating mirrors, and the like.

In other examples, the radar system does not include a scanning device. The transmit direction of each transmit channel and the receive direction of each receive channel are fixed.

Fig. 2 is a schematic structural diagram of a signal processing device according to an embodiment of the present application. As shown in fig. 2, the signal processing device 22 includes a detection unit 221 and a processing unit 222. The detection unit 221 is configured to convert the first echo signal into a first electrical signal, and convert the second echo signal into a second electrical signal. The first echo signal is obtained by reflecting a first transmitting signal through a target object, and the second echo signal is obtained by reflecting a second transmitting signal through the target object. The first transmission signal and the second transmission signal are two transmission signals which are transmitted by the radar system in the same direction. Here, two times in succession means two times adjacent in time. The processing unit 222 is configured to determine whether the target object moves based on the first time of flight corresponding to the first electrical signal and the second time of flight corresponding to the second electrical signal, and determine a detection result of the target object based on the second time of flight when determining that the target object moves.

In the embodiment of the present application, the first flight time may refer to a time interval between a transmission time of the first transmission signal and a reception time of the first echo signal, or the first flight time may refer to a time interval between a generation time of the driving signal of the first transmission signal and a reception time of the first electrical signal. Since the switching time between the optical signal and the electrical signal is extremely short and is essentially negligible, the two time intervals are essentially equal. Likewise, the second flight time may refer to a time interval between a transmission time of the second transmission signal and a reception time of the second echo signal, or the second flight time may refer to a time interval between a generation time of the driving signal of the second transmission signal and a reception time of the second electric signal.

In the embodiment of the application, whether the target object moves is determined based on the first flight time corresponding to the first electric signal and the second flight time corresponding to the second electric signal, and under the condition that the target object is determined to move, the detection result of the target object is determined based on the second flight time. I.e. only the detection result of a moving target object is of interest, whereas for an object that is not moving, no further processing of the electrical signal resulting from the echo signal conversion is necessary to determine the detection result. Compared with the detection result of determining the target object according to the corresponding flight time for each echo signal, the data volume required to be processed by the processing unit is reduced, and the requirement on the calculation processing capacity of the processing unit is reduced.

In some examples, the detection unit 221 includes a detector 2211 for converting received echo signals into electrical signals. For example, the first echo signal is converted into a first electrical signal and the second echo signal is converted into a second electrical signal. Illustratively, the detector is a photoelectric conversion device, such as a photodiode or the like, for converting a received optical signal (i.e., an echo signal) into an electrical signal.

In some examples, the detection unit 221 further includes a detector driving unit (not shown) for driving the detector into operation.

In some examples, the detection unit 221 further includes a transimpedance amplifier (TIA) 2212, the TIA2212 for amplifying the electrical signal output by the detector 2211. Since the intensity of the electrical signal output from the detector 2211 is weak, the accuracy of the subsequent processing can be improved by amplifying the electrical signal.

In one possible implementation, the processing unit 222 determines whether the target object is moving based on a difference between the first time of flight and the second time of flight. For example, when the absolute value of the difference between the first time of flight and the second time of flight is greater than a time threshold, the target object movement is indicated. For another example, when the absolute value of the difference between the first time of flight and the second time of flight is less than or equal to the time threshold, it is indicated that the target object is not moving. The time threshold may be set according to practical situations, which is not limited in this application.

In this embodiment, the processing unit 222 records the transmission time of the first transmission signal, the reception time of the first echo signal, the transmission time of the second transmission signal, and the reception time of the second echo signal, then determines the first flight time according to the transmission time of the first transmission signal and the reception time of the first echo signal, and determines the second flight time according to the transmission time of the second transmission signal and the reception time of the second echo signal.

In another possible implementation, the processing unit 222 determines whether the target object moves based on a difference between the first feature value and the second feature value. Here, the first characteristic value is used to indicate a first time of flight and the second characteristic value is used to indicate a second time of flight. I.e. a first time of flight can be calculated from the first characteristic value and a second time of flight can be calculated from the second characteristic value. For example, when the absolute value of the difference between the first feature value and the second feature value is greater than the feature value threshold, the target object movement is indicated. For another example, when the absolute value of the difference between the first characteristic value and the second characteristic value is less than or equal to the characteristic value threshold value, it is indicated that the target object is not moving. The threshold value of the characteristic value can be set according to practical situations, which is not limited in the application.

In this embodiment, the processing unit 222 includes: an electrical signal generation subunit 2221, a delay storage subunit 2222, and a processing subunit 2223.

Wherein, the electric signal generating subunit 2221 is configured to generate, in response to the reset signal, a reference electric signal whose characteristic value monotonically changes with time, and output, based on the reference electric signal, a first characteristic value corresponding to the first electric signal and a second characteristic value corresponding to the second electric signal. The first characteristic value is used for indicating a first time of flight and the second characteristic value is used for indicating a second time of flight. Because the first transmitting signal and the second transmitting signal are two transmitting signals which are transmitted by the radar system in the same direction, the first echo signal and the second echo signal are two echo signals which are received by the radar system in the same direction, the first electric signal and the second electric signal are electric signals corresponding to the two echo signals which are received by the signal processing device in sequence, and the first characteristic value and the second characteristic value are two characteristic values of the electric signal generating subunit 2221 in sequence.

The reset signal is synchronized with the driving signals of the first and second emission signals. That is, when the driving signal of the first emission signal is output to the laser, the electrical signal generating subunit 2221 receives a reset signal; when the driving signal of the second emission signal is output to the laser, the electrical signal generating subunit 2221 receives a reset signal again. The reset signal is used to instruct the electric signal generating subunit 2221 to reset the characteristic value of the reference electric signal, for example, to zero the characteristic value of the reference electric signal, or the like. The reset signal may be generated by a control device of the radar system for outputting the reset signal and a driving signal of the laser.

The delay storage subunit 2222 is configured to delay outputting the first characteristic value. Here, the delay time length corresponding to the delay storage subunit 222 is determined according to the time interval between two consecutive transmissions of the radar system in the same direction. For example, the delay time may be equal to the time interval between two consecutive transmissions of the radar system in the same direction.

It is assumed that a time interval in which one transmission channel of the radar system consecutively transmits two transmission signals is one detection period. When the radar system includes the scanning device, a time interval in which the radar system continuously transmits the transmission signal twice in the same direction is equal to a plurality of detection periods (i.e., a scanning period of one frame of point cloud data). When the radar system does not include the scanning device, the interval between two consecutive transmissions of the signal in the same direction by the radar system is equal to one detection period.

The processing subunit 2223 is configured to determine whether the target object moves based on the second characteristic value output by the electrical signal generating subunit 2221 and the first characteristic value output by the delay storage subunit 2222; and determining a detection result of the target object based on the second characteristic value when it is determined that the target object moves.

In the embodiment of the application, most of the circuits in the processing unit are analog circuits, for example, part of the circuits in the processing subunit, the electric signal generating subunit and the delay storage subunit, and the second flight time is determined by the form of the analog circuits, so that an ADC is not required, and the cost is reduced.

Illustratively, the characteristic values include, but are not limited to, voltage values, current values, frequency values, phase values, and the like. Optionally, the monotonic change in the characteristic value of the reference electrical signal over time comprises an increase or decrease. In some examples, the characteristic value of the reference electrical signal varies linearly with time. In other examples, the characteristic value of the reference electrical signal varies non-linearly over time.

The embodiments of the present application will be exemplarily described below with reference to an example in which a characteristic value is a voltage value and a characteristic value of an electrical signal linearly increases with time.

Fig. 3 is a schematic circuit diagram of a processing unit according to an embodiment of the present application. As shown in fig. 3, the electrical signal generating sub-unit 2221 includes: a current source I, a first switching device S1, an energy storage element C1, a second switching device S2 and a third switching device S3. The input end of the current source I is connected with the power supply VDD, the output end of the current source I is connected with one end of the first switching device S1, the other end of the first switching device S1 is connected with one end of the energy storage element C1, and the other end of the energy storage element C1 is grounded GND. The current source I is used to charge the energy storage element C1 when the first switching device S1 is closed, so as to generate a reference electric signal whose voltage value increases linearly with time. The second switching device S2 is connected in parallel with the energy storage element C1, and the second switching device S2 is used for being closed under the action of a reset signal, so as to zero the characteristic value of the reference electric signal. The input end of the third switching device S3 is connected with one end of the energy storage element C1, the output end of the third switching device S3 is connected with the delay storage subunit 2222 and the processing subunit 2223, and the third switching device S3 is configured to output a second characteristic value to the delay storage subunit 2222 and the processing subunit 2223.

Illustratively, the energy storage element C1 is a capacitor. The end of the energy storage element C1 connected with the first switching device S1 is a node a, and the voltage of the node a returns to zero when the reset signal arrives, and then increases linearly with time.

Illustratively, the control terminals of the first switching device S1 and the second switching device S2 are each connected to a reset signal input terminal for receiving a reset signal. In some examples, the first switching device S1 and the second switching device S2 are in opposite states under the action of a reset signal. For example, when the first switching device S1 is closed, the second switching device S2 is open; when the first switching device S1 is opened, the second switching device S2 is closed.

The first switching device S1 and the second switching device S2 are used for controlling the charge and discharge of the energy storage element C1, so that a reference electric signal with a voltage value which returns to zero when a reset signal arrives and then increases linearly with time is generated, and the circuit structure is simple. In addition, the characteristic value of the reference electric signal linearly increases along with time, so that the subsequent method for converting the flight time based on the characteristic value of the reference electric signal is simple, and the calculated amount is small.

Illustratively, the delay storage subunit 2222 includes a delay chain DL and an energy storage element C2. The delay chain DL may be a buffer (buffer) for delaying the first characteristic value output by the electrical signal generating subunit 2221. The energy storage element C2 is configured to store the first characteristic value delayed by the delay chain DL until the second characteristic value arrives, and replace the first characteristic value. Illustratively, the energy storage element C2 is a capacitor.

Illustratively, the processing subunit 2223 includes a first comparator P1, a fourth switching device S4, and a processing device Q. One input terminal of the first comparator P1 is connected to the electrical signal generating subunit 2221, and the other input terminal of the first comparator P1 is connected to the output terminal of the delay storage subunit 2222. The first comparator P1 is configured to determine a difference between the first characteristic value and the second characteristic value, the difference being used to reflect whether the target object moves. The control terminal of the fourth switching device S4 is connected to the output terminal of the first comparator P1, and the input terminal of the fourth switching device S4 is connected to the electrical signal generating subunit 2221. The fourth switching device S4 is configured to close when the absolute value of the difference is greater than the characteristic threshold value, so as to output a second characteristic value. When the absolute value of the difference is less than or equal to the characteristic value threshold, the fourth switching device S4 is turned off, and the second characteristic value is not output. The processing device Q is connected to the output terminal of the fourth switching device S4, and is configured to determine a detection result of the target object based on the second feature value.

Illustratively, the processing device Q may be a general purpose processor, a digital signal processor (digital signal drocessing, DSP), an application-specific integrated circuit (ASIC), or an off-the-shelf programmable gate array (field programmable gate array, FPGA), or the like.

In a possible embodiment, the control terminal of the third switching device S3 is configured to receive the trigger signal, and the third switching device S3 is turned on when receiving the trigger signal, so as to output a corresponding voltage value (i.e., a characteristic value). In some examples, the third switching device S3 is turned on upon receipt of the second electrical signal, i.e. the trigger signal is generated upon receipt of the second electrical signal. In other examples, the third switching device S3 is turned on when the amplitude of the second electrical signal exceeds the amplitude threshold, i.e. the trigger signal is turned on when the amplitude of the received second electrical signal exceeds the amplitude threshold. Because the radar system is in the environment where interference exists, noise signals exist in echo signals received by the radar system, and therefore, the noise signals can be screened out by setting a proper amplitude threshold. Here, the amplitude threshold value may be set according to actual needs, which is not limited in this application.

In order to screen out noise signals, the processing unit 222 further comprises a threshold decision subunit 2224, the threshold decision subunit 2224 being connected to the detection unit 221 and the electrical signal generating subunit 2221, respectively. The threshold decision subunit 2224 is configured to output the trigger signal when the amplitude of the second electrical signal is greater than the amplitude threshold. The electrical signal generating subunit 2221 is configured to output the second characteristic value according to the trigger signal.

Illustratively, the threshold decision subunit 2224 may include a second comparator P2. One input terminal of the second comparator P2 is connected to the output terminal of the detection unit 221, and the other input terminal of the second comparator P2 is connected to the reference voltage supply terminal REF. The reference voltage supply terminal REF is configured to supply a reference voltage, where the reference voltage corresponds to the amplitude threshold value. The output terminal of the second comparator P2 is connected to the electrical signal generating subunit 2221, i.e. to the control terminal of the third control switch S3.

In some examples, the processing subunit 2222 is configured to determine a second time of flight corresponding to the second characteristic value according to a rate of change of the characteristic value of the reference electrical signal; and determining the distance of the target object according to the second flight time. When the characteristic value of the reference electric signal linearly changes along with time, the corresponding relation between the characteristic value and time is a straight line, and the change rate of the characteristic value is the slope of the straight line. The second time of flight may be calculated using the following equation (1).

T＝V×C/I (1)

In the formula (1), T represents the second time of flight, V represents the second characteristic value, C represents the capacitance value of the capacitor in the electric signal generating subunit, and I represents the output current of the current source.

When the characteristic value of the reference electric signal is in nonlinear change, the change rule of the characteristic value needs to be determined in advance, and then the flight time is calculated according to the change rule of the characteristic value.

After the second flight time is determined, the distance of the target object can be determined according to the propagation speed of the laser and the second flight time.

When the radar system includes the scanning device, the interval between two consecutive transmissions of the signal in the same direction is equal to a plurality of detection periods. The same transmitting channel of the radar system transmits transmitting signals to different directions at different moments. Defining that the radar system finishes scanning the detection area once (namely finishes scanning one frame of point cloud data) as one scanning period, and then one scanning period comprises a plurality of detection periods. In one scanning period, the same transmitting channel of the radar system transmits transmitting signals to multiple directions, and correspondingly, the receiving channel corresponding to the transmitting channel receives echo signals in multiple directions.

In one possible embodiment, a plurality of processing units may be configured for each receiving channel, each processing unit for processing echo signals in one direction. The plurality of processing units are connected with the detection unit through a control switch. The control switch is provided with an input end and a plurality of output ends, wherein the input end is connected with the detection unit, and the plurality of output ends are respectively connected with a processing unit. The control end of the control switch is connected with a control device of the scanning module, the control device is used for controlling the conduction between the input end and a target output end, and the target output end is an output end connected with the target processing unit. The target processing unit is a processing unit corresponding to the current receiving direction of the receiving channel. It should be noted that a plurality of processing units may share one processing device.

In another possible implementation, the delay storage unit stores the feature values in a stack. I.e. the delay memory unit has a plurality of characteristic values stored therein and the plurality is output in the form of first-in first-out (first in first out, FIFO). The delay time length of the delay storage unit is equal to one scanning period, and the number of the characteristic values stored by the delay storage unit is equal to the number of points in one frame of point cloud data. In this way, when each echo signal is received, the corresponding characteristic value can be compared with the characteristic value of the echo signal in the corresponding direction in the previous scanning period. In this embodiment, the radar system including the scanning device may also employ a processing unit to determine whether the target object is moving, further simplifying the device structure.

The operation of the signal processing apparatus shown in fig. 2 will be described below.

The detection unit 221 receives the second echo signal, which is formed after the second transmission signal is reflected by the target object. The detection unit 221 converts the second echo signal into a second electrical signal, and outputs the second electrical signal to the threshold decision subunit 2221.

The threshold decision subunit 2224 determines whether the amplitude of the second electrical signal exceeds the amplitude threshold, and if the amplitude of the second electrical signal exceeds the amplitude threshold, which indicates that a valid second echo signal is received, outputs a trigger signal to the electrical signal generating subunit 2221. If the amplitude of the second electrical signal does not exceed the amplitude threshold, no trigger signal is output.

The electric signal generating sub-unit 2221 receives the reset signal when the second transmission signal is transmitted. In response to the reset signal, a reference electrical signal is generated, the characteristic value of which monotonically varies with time. The electrical signal generating subunit 2221 outputs the current characteristic value of the reference electrical signal, that is, the second characteristic value corresponding to the second electrical signal, when receiving the trigger signal output by the threshold determining subunit 2224.

The delay storage subunit 2222 receives the second feature value, and performs delay storage on the second feature value, so as to determine whether the target object moves in the next detection period. In addition, the delay storage subunit 2222 stores therein a first characteristic value that is generated based on a first echo signal that is an echo signal detected in a preceding detection period of a second echo signal, and the reception directions of the first echo signal and the second echo signal are the same. The first characteristic value is generated in the same manner as the second characteristic value.

The processing subunit 2223 receives the second characteristic value output by the electrical signal generating subunit 2221 and the first characteristic value output by the delay storage subunit 2222, and compares the first characteristic value with the second characteristic value. If the absolute value of the difference between the first characteristic value and the second characteristic value is greater than the characteristic value threshold, calculating a second flight time according to the second characteristic value, and determining the distance of the target object according to the second flight time.

Fig. 4 is a schematic structural diagram of another signal processing device according to an embodiment of the present application. The signal processing apparatus shown in fig. 4 differs from the signal processing apparatus shown in fig. 2 in that in fig. 4, the signal processing apparatus further includes a sampling unit 223. The sampling unit 223 is configured to sample the amplitude of the second electrical signal when it is determined that the target object moves, so as to obtain a sampling result. The processing unit 222 is further configured to determine a reflectivity of the target object based on the sampling result.

In one possible embodiment, the sampling unit 223 includes a sample holder 2231, a fifth switching device 2232, and an ADC2233. The sample-and-hold 2231 is coupled to the threshold decision subunit 2224 for sampling and holding the amplitude of the second electrical signal and outputting a sample-and-hold signal. The control terminal of the fifth switching device 2232 is connected to the processing unit 222 (e.g., connected to the output terminal of the first comparator P1 in fig. 3), the input terminal of the fifth switching device 2232 is connected to the output terminal of the sample-and-hold unit 2231, and the fifth switching device 2232 is configured to be turned on by the control signal output from the processing unit 222. The ADC2233 is connected to an output terminal of the fifth switching device 2232, and is configured to sample the sample-and-hold signal when the fifth switching device 2232 is turned on, so as to obtain a sampling result.

The sample-and-hold unit 2231 is a device whose operation state is controlled by a logic level, and is a logic gate circuit having a signal input, a signal output, and controlled by an external command. The sample holder samples the value of the processed signal (e.g., the second electrical signal) under the control of an external command (i.e., the aforementioned trigger signal), and then stores the sampled value for a period of time for ADC conversion until the next external command arrives, and samples the value of the processed signal again. The external command may be generated by the aforementioned control device.

Illustratively, the sample-and-hold may include an analog switch, a storage element (e.g., a capacitor), and a buffer amplifier. At the sampling instant, the trigger signal applied to the analog switch is low, at which time the analog switch is turned on, causing the voltage across the storage element to vary with the sampled signal. When the sampling interval is terminated, the trigger signal goes high, the analog switch is turned off, and the voltage across the storage element remains unchanged at the off-instant value. The buffer amplifier functions to amplify the sampled signal.

And when the amplitude of the second electric signal is larger than the amplitude threshold value, the amplitude of the second electric signal is sampled and held through the sampling holder until one detection period is ended. Therefore, the ADC only needs to sample the sample hold signal once in one detection period, so that a sampling result can be obtained, and the sampling rate of the ADC is low. Since the price of an ADC is typically positively correlated with the sampling rate, the higher the price of the ADC. Therefore, the use of an ADC with a low sampling rate is advantageous in reducing the cost of the signal processing apparatus.

Fig. 5 is a signal timing diagram for use in the signal processing apparatus of fig. 4. As shown in fig. 5, the reset signal is synchronized with the transmit signal. Tk represents the time interval between the first transmit signal and the first echo signal, i.e. the first time of flight. Tk+1 represents the time interval between the second transmit signal and the second echo signal, i.e. the second time of flight. The reference electrical signal is zeroed at the reset signal and then increases linearly with time. Vk represents a characteristic value (voltage value) of the reference electric signal corresponding to the reception time of the first echo signal, that is, a first characteristic value. Vk+1 represents a characteristic value of the reference electric signal corresponding to the reception time of the second echo signal, that is, a second characteristic value. The position of the rising edge of the sample-and-hold signal corresponds to the position of the echo signal, and the falling edge is at the end position of each detection period. Each detection period has an ADC sampling point, that is, each echo signal corresponds to an ADC sampling point, and the sampling time corresponding to each ADC sampling point is close to the end of the detection period. In the embodiment of the application, the time interval between the ADC sampling point and the detection period end position is the minimum time interval supported by the ADC, so as to avoid affecting the detection of the echo signal. The minimum time interval is determined by the sampling rate of the ADC.

In another possible embodiment, the sampling unit comprises an ADC. The input of the ADC is connected to the output of the detection unit 221. Since it is uncertain at which time of the corresponding detection period the echo signal will be received, the sampling rate of the ADC needs to be high, and the second electrical signal is sampled at high speed throughout the detection period. By adopting the mode for sampling, the device used is few, and the structure is simple.

Illustratively, the processing unit 222 determines the reflectivity of the target object in the following manner: and multiplying the ratio of the sampling result to the amplitude of the emission signal by a correction coefficient to obtain the reflectivity of the target object. The correction coefficient is a set value, and can be determined according to the environment. The embodiments of the present application do not limit the manner in which reflectivity is determined.

In some examples, the structure of fig. 2 or 4 may be integrated on one chip or circuit board. In other examples, portions other than the processing device may be integrated on one chip or circuit board, while the processing device is disposed on another chip or circuit board.

Fig. 6 is a flowchart of a signal processing method of a radar system according to an embodiment of the present application. As shown in fig. 6, the method includes:

S61: obtaining a first electric signal and a second electric signal, wherein the first electric signal is obtained by converting a first echo signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, the second electric signal is obtained by converting a second echo signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by a radar system in the same direction and are transmitted twice in sequence;

s62: determining whether the target object moves based on the first flight time corresponding to the first electric signal and the second flight time corresponding to the second electric signal;

s63: when it is determined that the target object is moving, a detection result of the target object is determined based on the second flight time.

Illustratively, the detection result of the target object includes at least a distance of the target object. Optionally, the detection result of the target object further includes reflectivity or the like.

When it is determined that the target object does not move, the detection result of the target object does not need to be determined.

In some examples, S62 includes: the method comprises the steps of determining a first characteristic value corresponding to a first electric signal and a second characteristic value corresponding to a second electric signal, wherein the first characteristic value is used for indicating first flight time, the second characteristic value is used for indicating second flight time, and the first characteristic value and the second characteristic value are determined based on a corresponding relation between the characteristic value and time, and in the corresponding relation, the characteristic value monotonically changes along with time; and a second step of determining whether the target object moves or not based on the first characteristic value and the second characteristic value.

In one embodiment, the correspondence may be implemented in hardware circuitry, such as the circuitry shown in FIG. 3.

In some examples, S63 includes: determining a second flight time corresponding to the second characteristic value according to the change rate of the characteristic value in the corresponding relation; and determining the distance of the target object according to the second flight time.

In some examples, the characteristic value is a voltage value and the characteristic value of the reference electrical signal increases linearly with time. Determining a second characteristic value corresponding to the second electrical signal includes: and when the amplitude of the second electric signal is larger than the amplitude threshold value, determining the characteristic value corresponding to the receiving time of the second echo signal as a second characteristic value.

When the detection result of the target object includes the reflectivity of the target object, the method further includes: when the movement of the target object is determined, sampling the amplitude of the second electric signal to obtain a sampling result; and determining the reflectivity of the target object based on the sampling result.

Fig. 7 is a schematic structural diagram of a signal processing device of a radar system according to an exemplary embodiment of the present application. The apparatus may be implemented as part or all of an apparatus by software, hardware, or a combination of both. The device provided by the embodiment of the application can realize the flow of fig. 5 of the embodiment of the application. As shown in fig. 7, the apparatus 700 includes: the obtaining module 701, the first determining module 702 and the second determining module 703. The obtaining module 701 is configured to obtain a first electrical signal and a second electrical signal, where the first electrical signal is obtained by converting a first echo signal, the first echo signal is obtained by reflecting a first transmission signal by a target object, the second electrical signal is obtained by converting a second echo signal, the second echo signal is obtained by reflecting a second transmission signal by reflecting a target object, and the first transmission signal and the second transmission signal are two transmission signals that are transmitted by the radar system in the same direction. The first determining module 702 is configured to determine whether the target object moves based on a first time of flight corresponding to the first electrical signal and a second time of flight corresponding to the second electrical signal. The second determining module 703 is configured to determine a detection result of the target object based on the second flight time when it is determined that the target object moves.

In some examples, the first determining module 702 is configured to determine a first characteristic value corresponding to the first electrical signal and a second characteristic value corresponding to the second electrical signal, the first characteristic value being used to indicate the first time of flight and the second characteristic value being used to indicate the second time of flight, the first characteristic value and the second characteristic value each being determined based on a correspondence between characteristic values and time in which characteristic values monotonically change over time; based on the first and second eigenvalues, it is determined whether the target object is moving.

In some examples, the first determination module 702 determines the second feature value in the following manner: and when the amplitude of the second electric signal is larger than an amplitude threshold value, determining a characteristic value corresponding to the receiving time of the second echo signal as the second characteristic value.

In some examples, the detection result of the target object includes a distance of the target object; the second determining module 703 is configured to determine the second time of flight corresponding to the second feature value according to a rate of change of the feature value in the correspondence; and determining the distance of the target object according to the second flight time.

In some examples, the detection result of the target object includes a reflectivity of the target object; the apparatus further comprises: a sampling module 704. The sampling module 704 is configured to sample the amplitude of the second electrical signal when it is determined that the target object moves, so as to obtain a sampling result; the second determining module 703 is further configured to determine a reflectivity of the target object based on the sampling result.

It should be noted that: in the signal processing device provided in the above embodiment, only the division of the above functional modules is used for illustration when processing echo signals, and in practical application, the above functional allocation may be performed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules, so as to perform all or part of the functions described above. In addition, the signal processing device and the signal processing method provided in the foregoing embodiments belong to the same concept, and specific implementation processes of the signal processing device and the signal processing method are detailed in the method embodiments and are not repeated herein.

In the embodiments of the present application, the division of the modules is schematically only one logic function division, and other division manners may be adopted in actual implementation, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, may exist alone physically, or may be integrated into one module. The integrated modules may be implemented in hardware or in software functional modules.

The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in whole or in part in the form of a software product stored in a storage medium, comprising several instructions for causing a terminal device (which may be a personal computer, a mobile phone, or a communication device, etc.) or a processor (processor) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

A computer device is also provided in an embodiment of the present application, and fig. 8 illustrates one possible architecture diagram of a computer device 800.

Computer device 800 includes memory 801, processor 802, communication interface 803, and bus 804. Wherein the memory 801, the processor 802 and the communication interface 803 are communicatively connected to each other through a bus 804.

The memory 801 may be a ROM, static storage device, dynamic storage device, or RAM. The memory 801 may store a program, and when the program stored in the memory 801 is executed by the processor 802, the processor 802 and the communication interface 803 are used to perform a device access method. The memory 801 may also store data sets such as: a part of the storage resources in the memory 801 is divided into a data storage module for storing the sampled signals corresponding to the I-channel electric signal and the mixed electric signal, and the like.

The processor 802 may employ a general purpose CPU, microprocessor, ASIC, graphics processor (graphics processing unit, GPU) or one or more integrated circuits.

The processor 802 may also be an integrated circuit chip with signal processing capabilities. In implementation, some or all of the functions of the echo signal processing device of the present application may be implemented by integrated logic circuits of hardware in the processor 802 or instructions in the form of software. The processor 802 described above may also be a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The methods disclosed in the above embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in the memory 801, and the processor 802 reads information in the memory 801, and in combination with its hardware, performs part of the functions of the signal processing device of the radar system of the embodiment of the present application.

Communication interface 803 enables communication between computer device 800 and other devices or communication networks using a transceiver module such as, but not limited to, a transceiver. For example, the first electrical signal and the second electrical signal, etc., may be acquired through the communication interface 803.

Bus 804 may include a path for transferring information between various components of computer device 800 (e.g., memory 801, processor 802, communication interface 803).

The descriptions of the processes corresponding to the drawings have emphasis, and the descriptions of other processes may be referred to for the parts of a certain process that are not described in detail.

In an embodiment of the present application, there is also provided a computer-readable storage medium storing computer instructions that, when executed by a computer device, cause the computer device to perform the signal processing method provided above.

In an embodiment of the present application, there is also provided a computer program product comprising instructions which, when run on a computer device, cause the computer device to perform the signal processing method provided above.

In the embodiment of the application, a chip is further provided for executing the signal processing method shown in fig. 5.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," "third," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" and the like means that elements or items appearing before "comprising" are encompassed by the element or item listed after "comprising" and equivalents thereof, and that other elements or items are not excluded.

The foregoing description is provided for the purpose of illustration only and is not intended to limit the invention to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, alternatives, and alternatives falling within the spirit and scope of the invention.

Claims

1. A signal processing apparatus of a radar system, the signal processing apparatus comprising: a detection unit and a processing unit;

The detection unit is used for converting a first echo signal into a first electric signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, and converting a second echo signal into a second electric signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by the radar system in the same direction and are transmitted by two times in sequence;

the processing unit is used for determining whether the target object moves or not based on a first flight time corresponding to the first electric signal and a second flight time corresponding to the second electric signal, and determining a detection result of the target object based on the second flight time when the target object is determined to move.

2. The signal processing device of claim 1, wherein the processing unit comprises: an electrical signal generating subunit, a delay storage subunit and a processing subunit;

the electric signal generating subunit is configured to generate a reference electric signal whose characteristic value changes monotonically with time in response to a reset signal, and output, based on the reference electric signal, a first characteristic value corresponding to the first electric signal and a second characteristic value corresponding to the second electric signal, the first characteristic value being used to indicate the first time of flight, the second characteristic value being used to indicate the second time of flight, the reset signal being synchronized with driving signals of the first emission signal and the second emission signal;

The delay storage subunit is used for carrying out delay output on the first characteristic value;

the processing subunit is used for determining whether the target object moves or not based on the second characteristic value output by the electric signal generating subunit and the first characteristic value output by the delay storage subunit; and determining a detection result of the target object based on the second characteristic value when it is determined that the target object moves.

3. The signal processing device according to claim 2, wherein the characteristic value is a voltage value;

the electrical signal generating subunit includes: a current source, a first switching device, an energy storage element, a second switching device and a third switching device;

the input end of the current source is connected with a power supply, the output end of the current source is connected with one end of the first switching device, the other end of the first switching device is connected with one end of the energy storage element, and the other end of the energy storage element is grounded;

the current source is used for charging the energy storage element when the first switching device is closed so as to generate a reference electric signal with the voltage value linearly increasing along with time;

the second switching device is connected with the energy storage element in parallel, and is used for being closed under the action of the reset signal so as to zero the characteristic value of the reference electric signal;

The input end of the third switching device is connected with one end of the energy storage element, the output end of the third switching device is respectively connected with the delay storage subunit and the processing subunit, and the third switching device is used for outputting the second characteristic value to the delay storage subunit and the processing subunit.

4. A signal processing apparatus according to claim 2 or 3, wherein the processing subunit comprises a first comparator, a fourth switching device and a processing device;

one input end of the first comparator is connected with the electric signal generation subunit, the other input end of the first comparator is connected with the output end of the delay storage subunit, and the difference value between the first characteristic value and the second characteristic value is used for determining whether the target object moves or not;

the control end of the fourth switching device is connected with the output end of the first comparator, the input end of the fourth switching device is connected with the electric signal generation subunit, and the fourth switching device is used for outputting the second characteristic value when the absolute value of the difference value is larger than a characteristic value threshold value;

The processing device is connected with the output end of the fourth switching device and is used for determining the detection result of the target object based on the second characteristic value.

5. The signal processing apparatus according to any one of claims 2 to 4, wherein the detection result of the target object includes a distance of the target object;

the processing subunit is used for determining the second flight time corresponding to the second characteristic value according to the change rate of the characteristic value of the reference electric signal; and determining the distance of the target object according to the second flight time.

6. The signal processing device according to any one of claims 2 to 5, wherein the processing unit further comprises a threshold decision subunit connected to the detection unit and the electrical signal generation subunit, respectively;

the threshold value judging subunit is used for outputting a trigger signal when the amplitude value of the second electric signal is larger than an amplitude value threshold value;

the electric signal generation subunit is used for outputting the second characteristic value according to the trigger signal.

7. The signal processing apparatus according to any one of claims 1 to 6, wherein the detection result of the target object includes a reflectance of the target object;

The signal processing device further comprises a sampling unit, a sampling unit and a sampling unit, wherein the sampling unit is used for sampling the amplitude of the second electric signal when the target object is determined to move, so as to obtain a sampling result;

the processing unit is further configured to determine a reflectivity of the target object based on the sampling result.

8. The signal processing apparatus of claim 7, wherein the sampling unit comprises: a sample holder, a fifth switching device and an analog-to-digital converter ADC;

the sample holder is used for sampling and holding the amplitude of the second electric signal and outputting a sample holding signal;

the control end of the fifth switching device is connected with the processing unit, the input end of the fifth switching device is connected with the output end of the sampling holder, the fifth switching device is used for being conducted under the action of a control signal output by the processing unit, and the control signal is output by the processing unit when the target object is determined to move;

the ADC is connected with the output end of the fifth switching device and is used for sampling the sampling hold signal when the fifth switching device is conducted, so that the sampling result is obtained.

9. A method of signal processing for a radar system, the method comprising:

obtaining a first electric signal and a second electric signal, wherein the first electric signal is obtained by converting a first echo signal, the first echo signal is obtained by reflecting a first transmitting signal by a target object, the second electric signal is obtained by converting a second echo signal, the second echo signal is obtained by reflecting a second transmitting signal by reflecting the target object, and the first transmitting signal and the second transmitting signal are two transmitting signals which are transmitted by the radar system to the same direction in sequence;

determining whether the target object moves based on a first flight time corresponding to the first electrical signal and a second flight time corresponding to the second electrical signal; and

and when the target object is determined to move, determining a detection result of the target object based on the second flight time.

10. The method of claim 9, wherein the determining whether the target object is moving based on a first time of flight corresponding to the first electrical signal and a second time of flight corresponding to a second electrical signal comprises:

determining a first characteristic value corresponding to the first electric signal and a second characteristic value corresponding to the second electric signal, wherein the first characteristic value is used for indicating the first flight time, the second characteristic value is used for indicating the second flight time, and the first characteristic value and the second characteristic value are determined based on a corresponding relation between the characteristic value and time, and in the corresponding relation, the characteristic value monotonically changes along with time;

Based on the first and second eigenvalues, it is determined whether the target object is moving.

11. The method of claim 10, wherein the detection result of the target object comprises a distance of the target object;

the determining the detection result of the target object based on the second flight time corresponding to the second electric signal includes:

determining the second flight time corresponding to the second characteristic value according to the change rate of the characteristic value in the corresponding relation; and

and determining the distance of the target object according to the second flight time.

12. The method according to claim 10 or 11, wherein determining the second characteristic value corresponding to the second electrical signal comprises:

and when the amplitude of the second electric signal is larger than an amplitude threshold value, determining a characteristic value corresponding to the receiving time of the second echo signal as the second characteristic value.

13. The method according to any one of claims 9 to 12, wherein the detection result of the target object comprises a reflectivity of the target object;

the method further comprises the steps of:

when the target object is determined to move, sampling the amplitude of the second electric signal to obtain a sampling result; and

And determining the reflectivity of the target object based on the sampling result.

14. A computer device, the computer device comprising a processor and a memory; the memory is used for storing a software program, and the processor is used for enabling the computer device to realize the method according to any one of claims 9 to 13 by executing the software program stored in the memory.

15. A computer readable storage medium storing computer instructions which, when executed by a computer device, cause the computer device to perform the method of any one of claims 9 to 13.

16. A radar system, characterized in that the radar system comprises a transmitting means and a receiving means;

the transmitting device is used for transmitting a first transmitting signal and a second transmitting signal, wherein the first transmitting signal and the second transmitting signal are transmitting signals which are transmitted by the radar system twice in sequence in the same direction;

the receiving device is configured to receive a first echo signal and a second echo signal, the first echo signal being obtained by reflecting the first transmission signal from a target object, the second echo signal being obtained by reflecting the second transmission signal from the target object, and the receiving device comprises the signal processing device according to any one of claims 1 to 8.