CN118254604A - Vehicle control method and device - Google Patents

Abstract

The present invention relates to the field of vehicle control technologies, and in particular, to a vehicle control method and device. The method comprises the following steps: acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle; determining a target state and a current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque; and if the current state is a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, obtaining a first target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and controlling the torque of the motor according to the first target motor torque. Therefore, through real-time judgment of the zero crossing interval and torque control of the motor, balance of power response speed and vehicle impact in the acceleration and deceleration process is achieved, drivability and smoothness of the whole vehicle are improved, and use experience of a user is improved.

Description

Vehicle control method and device

Technical Field

The present invention relates to the field of vehicle control, and in particular, to a vehicle control method and apparatus.

Background

With the continued development of new energy vehicles, zero crossing of motor torque is a fundamental common problem that all new energy vehicles must consider. The power system of the vehicle transmits torque from a power source to a wheel end through a plurality of components, and due to the torsion characteristics of the components and gaps existing between the transmission components, when the transition working condition is changed according to the wishes of a driver, such as instant acceleration or reversing, the driving wheel drives the driven wheel to rotate under the driving of the motor, at the moment, the driving wheel gear is meshed with the driven wheel gear on one side, but a larger gap exists on the other side, so that the whole shaking and noise of the vehicle are generated, special treatment is needed in the torque change process, and the shaking of the transmission system and impact feeling caused by direct torque change are eliminated.

In the related art, different filtering methods are generally selected to filter the torque change process according to modes, different conditions or different division regions, the required torque is divided into different regions to find zero crossing regions, the vehicle impact of the transition working condition is reduced, and the smoothness and the driving performance of the whole vehicle are improved.

However, the main problem of the above technical solution is that the zero crossing state is judged by the motor torque or the driver demand torque, which is obtained according to experience value or experiment. And because certain dispersion differences exist in the states of system components of the vehicles, torque precision and the like, all the vehicles can be covered in order to ensure the zero-crossing interval, the zero-crossing interval is set to be larger, and therefore the power delay of the whole vehicle is larger.

Disclosure of Invention

The invention provides a vehicle control method and device, which are used for solving the problem of larger power delay of the whole vehicle caused by larger zero crossing interval setting in the related technology, and realizing the balance of power response speed and vehicle impact in the acceleration and deceleration process by judging the zero crossing interval in real time and controlling the torque of a motor, thereby improving the drivability and smoothness of the whole vehicle and improving the user experience.

To achieve the above object, an embodiment of a first aspect of the present invention provides a control method for a vehicle, including the steps of:

Acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle;

Determining a target state and a current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque;

And if the current state is a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, obtaining a first target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and controlling the torque of the motor according to the first target motor torque.

According to an embodiment of the present invention, after determining that the current state is the driving state and the target state is the recovery state, it further includes:

judging whether the actual torque of the current wheel end is larger than a first preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a second preset torque threshold value or not, wherein the first preset torque threshold value is smaller than the second preset torque threshold value or not;

And if the current wheel end actual torque is larger than the first preset torque threshold value and the current wheel end actual torque is smaller than the second preset torque threshold value, judging that the current wheel end actual torque is in the preset negative zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the first preset torque threshold and whether the current wheel end actual torque is less than the second preset torque threshold, the method further includes:

Controlling the vehicle to be in a parking state, and acquiring a first actual torque when the motor rotating speed meets a first preset fluctuation condition and acquiring a second actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a first initial value to a first target value based on a first preset speed;

and obtaining the second preset torque threshold according to the sum of the first actual torque and the first reserved torque, and obtaining the first preset torque threshold according to the difference between the second actual torque and the second reserved torque.

According to one embodiment of the present invention, the obtaining the first target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque includes:

determining a first motor torque change rate limit value according to the motor speed change rate;

determining a second motor torque change rate limit value according to the actual motor torque;

Determining a third motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the first target motor torque according to the sum of the actual motor torque and the maximum value of the first motor torque change rate limiting value, the second motor torque change rate limiting value and the third motor torque change rate limiting value.

According to one embodiment of the present invention, after determining the target state and the current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque, further comprising:

And if the current state is the recovery state and the target state is the driving state, when the actual torque of the current wheel end is in a preset forward zero crossing interval, obtaining a second target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by the driver, and controlling the torque of the motor according to the second target motor torque.

According to an embodiment of the present invention, after determining that the current state is the recovery state and the target state is the driving state, it further includes:

Judging whether the actual torque of the current wheel end is larger than a third preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a fourth preset torque threshold value or not, wherein the third preset torque threshold value is smaller than the fourth preset torque threshold value;

and if the actual torque of the current wheel end is larger than the third preset torque threshold value and the actual torque of the current wheel end is smaller than the fourth preset torque threshold value, judging that the actual torque of the current wheel end is in the preset positive zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the third preset torque threshold and whether the current wheel end actual torque is less than the fourth preset torque threshold, the method further includes:

Controlling the vehicle to be in a parking state, and acquiring a third actual torque when the motor rotating speed meets a second preset fluctuation condition and acquiring a fourth actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a second initial value to a second target value based on a second preset speed;

And obtaining the third preset torque threshold according to the difference value of the third actual torque and the third reserved torque, and obtaining the fourth preset torque threshold according to the sum value of the fourth actual torque and the fourth reserved torque.

According to one embodiment of the present invention, the obtaining the second target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque includes:

determining a fourth motor torque change rate limiting value according to the motor rotation speed change rate;

determining a fifth motor torque change rate limit value according to the actual motor torque;

Determining a sixth motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the second target motor torque according to the sum of the actual motor torque and the minimum value of the fourth motor torque change rate limiting value, the fifth motor torque change rate limiting value and the sixth motor torque change rate limiting value.

According to one embodiment of the present invention, the determining the target state and the current state of the vehicle according to the current accelerator opening and the current wheel end actual torque includes:

judging whether the torque required by the driver is larger than or equal to a first preset value according to the current accelerator pedal opening;

if the driver demand torque is greater than or equal to the first preset value, judging the target state as a driving state, otherwise, judging the target state as the recovery state;

judging whether the actual torque of the current wheel end is smaller than a second preset value or not;

And if the actual torque of the current wheel end is smaller than the second preset value, judging that the current state is the recovery state, otherwise, judging that the current state is the driving state.

According to the control method of the vehicle, the target state and the current state of the vehicle are determined according to the current accelerator pedal opening and the current wheel end actual torque by acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle; when the current state is judged to be a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, a first target motor torque is obtained according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and torque control is performed on the motor according to the first target motor torque. Therefore, through real-time judgment of the zero crossing interval and torque control of the motor, balance of power response speed and vehicle impact in the acceleration and deceleration process is achieved, drivability and smoothness of the whole vehicle are improved, and use experience of a user is improved.

To achieve the above object, a second aspect of the present invention provides a control device for a vehicle, comprising:

the acquisition module is used for acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle;

The judging module is used for determining a target state and a current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque;

and the control module is used for obtaining a first target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque when the current wheel end actual torque is in a preset negative zero crossing interval and controlling the motor torque according to the first target motor torque if the current state is a driving state and the target state is a recovery state.

According to one embodiment of the present invention, after determining that the current state is the driving state and the target state is the recovery state, the control module is further configured to:

judging whether the actual torque of the current wheel end is larger than a first preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a second preset torque threshold value or not, wherein the first preset torque threshold value is smaller than the second preset torque threshold value or not;

And if the current wheel end actual torque is larger than the first preset torque threshold value and the current wheel end actual torque is smaller than the second preset torque threshold value, judging that the current wheel end actual torque is in the preset negative zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the first preset torque threshold and whether the current wheel end actual torque is less than the second preset torque threshold, the control module is further configured to:

Controlling the vehicle to be in a parking state, and acquiring a first actual torque when the motor rotating speed meets a first preset fluctuation condition and acquiring a second actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a first initial value to a first target value based on a first preset speed;

and obtaining the second preset torque threshold according to the sum of the first actual torque and the first reserved torque, and obtaining the first preset torque threshold according to the difference between the second actual torque and the second reserved torque.

According to one embodiment of the present invention, the control module is specifically configured to:

determining a first motor torque change rate limit value according to the motor speed change rate;

determining a second motor torque change rate limit value according to the actual motor torque;

Determining a third motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the first target motor torque according to the sum of the actual motor torque and the maximum value of the first motor torque change rate limiting value, the second motor torque change rate limiting value and the third motor torque change rate limiting value.

According to one embodiment of the present invention, after determining the target state and the current state of the vehicle according to the current accelerator opening and the current wheel end actual torque, the determination module includes:

And the forward zero crossing unit is used for obtaining a second target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque when the current state is the recovery state and the target state is the driving state and the actual torque of the current wheel end is in a preset forward zero crossing interval, and controlling the motor torque according to the second target motor torque.

According to an embodiment of the present invention, after determining that the current state is the recovery state and the target state is the driving state, the positive zero crossing unit is further configured to:

Judging whether the actual torque of the current wheel end is larger than a third preset torque threshold value or not, wherein the actual torque of the current wheel end is smaller than a fourth preset torque threshold value, and the third preset torque threshold value is smaller than the fourth preset torque threshold value;

and if the actual torque of the current wheel end is larger than the third preset torque threshold value and the actual torque of the current wheel end is smaller than the fourth preset torque threshold value, judging that the actual torque of the current wheel end is in the preset positive zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the third preset torque threshold and whether the current wheel end actual torque is less than the fourth preset torque threshold, the positive zero crossing unit is further configured to:

Controlling the vehicle to be in a parking state, and acquiring a third actual torque when the motor rotating speed meets a second preset fluctuation condition and acquiring a fourth actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a second initial value to a second target value based on a second preset speed;

And obtaining the third preset torque threshold according to the difference value of the third actual torque and the third reserved torque, and obtaining the fourth preset torque threshold according to the sum value of the fourth actual torque and the fourth reserved torque.

According to one embodiment of the invention, the forward zero crossing unit is specifically configured to:

determining a fourth motor torque change rate limiting value according to the motor rotation speed change rate;

determining a fifth motor torque change rate limit value according to the actual motor torque;

Determining a sixth motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the second target motor torque according to the sum of the actual motor torque and the minimum value of the fourth motor torque change rate limiting value, the fifth motor torque change rate limiting value and the sixth motor torque change rate limiting value.

According to an embodiment of the present invention, the judging module is specifically configured to:

judging whether the torque required by the driver is larger than or equal to a first preset value according to the current accelerator pedal opening;

if the driver demand torque is greater than or equal to the first preset value, judging the target state as a driving state, otherwise, judging the target state as the recovery state;

judging whether the actual torque of the current wheel end is smaller than a second preset value or not;

And if the actual torque of the current wheel end is smaller than the second preset value, judging that the current state is the recovery state, otherwise, judging that the current state is the driving state.

According to the control device of the vehicle, the target state and the current state of the vehicle are determined according to the current accelerator pedal opening and the current wheel end actual torque by acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle; when the current state is judged to be a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, a first target motor torque is obtained according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and torque control is performed on the motor according to the first target motor torque. Therefore, through real-time judgment of the zero crossing interval and torque control of the motor, balance of power response speed and vehicle impact in the acceleration and deceleration process is achieved, drivability and smoothness of the whole vehicle are improved, and use experience of a user is improved.

To achieve the above object, an embodiment of a third aspect of the present invention provides a vehicle, including: the control system includes a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the control method of the vehicle as described in the above embodiments.

To achieve the above object, a fourth aspect of the present invention provides a computer-readable storage medium having stored thereon a computer program that is executed by a processor for realizing the control method of a vehicle as described in the above embodiments.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

fig. 1 is a flowchart of a control method of a vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a negative zero crossing process control method according to one embodiment of the invention;

FIG. 3 is a linear variation diagram of a torque variation slope control method according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a forward zero crossing process control method according to one embodiment of the present invention;

FIG. 5 is a flow chart of a method for controlling a vehicle according to an embodiment of the invention;

FIG. 6 is a block schematic diagram of a control device for a vehicle according to one embodiment of the invention;

fig. 7 is a schematic structural diagram of a vehicle according to an embodiment of the present invention.

Wherein, 10-a control device of the vehicle; 100-acquisition module, 200-judgment module and 300-control module; 701-memory, 702-processor, 703-communication interface.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

The following describes a control method and apparatus for a vehicle according to an embodiment of the present invention with reference to the accompanying drawings. First, a control method of a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Fig. 1 is a flowchart of a control method of a vehicle according to an embodiment of the present invention.

As shown in fig. 1, the control method of the vehicle includes the steps of:

In step S101, a current accelerator pedal opening and a current wheel end actual torque of the vehicle are acquired.

The accelerator pedal opening is an opening and closing angle of the accelerator pedal after the driver applies force to the accelerator pedal.

Specifically, in the embodiment of the invention, the opening degree of an accelerator pedal and the actual torque of the current wheel end of the vehicle can be obtained through an ECU (Electronic Control Unit, an electronic control unit) of the vehicle. When a driver presses an accelerator pedal, an acceleration system of the vehicle detects the opening degree of the accelerator pedal through a sensor and transmits a signal to an ECU of the vehicle; meanwhile, in the running process of the vehicle, the ECU can also obtain the current actual torque of the wheel end of the vehicle according to the rotation rate of the wheels.

In step S102, a target state and a current state of the vehicle are determined according to the current accelerator pedal opening and the current wheel end actual torque.

It will be appreciated that during driving conditions, the driver may determine the current driving conditions and the surrounding environment and the driving state of the vehicle at that moment, and apply different forces to the accelerator pedal. The intentions of slow acceleration and deceleration, general acceleration and deceleration and emergency acceleration and deceleration are expressed as the change of acceleration and deceleration pedals, and the opening of the acceleration pedal is smaller under the intentions of a driver in slow speed change; the accelerator pedal opening is large in the intention of abrupt shifting by the driver.

Optionally, in some embodiments, determining the target state and the current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque includes: judging whether the torque required by the driver is greater than or equal to a first preset value according to the current accelerator pedal opening; if the driver demand torque is greater than or equal to a first preset value, judging the target state as a driving state, otherwise, judging the target state as a recovery state; judging whether the actual torque of the current wheel end is smaller than a second preset value or not; if the actual torque of the current wheel end is smaller than the second preset value, the current state is judged to be the recovery state, otherwise, the current state is judged to be the driving state.

The first preset value and the second preset value may be torque limiting data set by a person skilled in the art according to actual requirements, or may be data obtained through limited computer simulation, which is not specifically limited herein.

Specifically, the target state of the vehicle is a new running state which is achieved after the driver accelerates or decelerates, one means of the acceleration of the vehicle is that the driver applies force to the accelerator pedal to open and close the accelerator pedal by a certain angle, so that the required torque of the driver can be obtained through the opening degree of the accelerator pedal, and then the target state of the vehicle is judged according to the required torque. The current state of the vehicle is determined by the current wheel end torque.

For example, one embodiment of the present invention provides that the first preset value and the second preset value are both zero, the target state is the driving state when the required torque is greater than or equal to zero, and the target state is the recovery state when the required torque is less than zero; when the actual torque of the wheel end is larger than zero, the current state is a driving state, and when the actual torque is smaller than zero, the current state is a recovery state.

In step S103, if the current state is a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, a first target motor torque is obtained according to the motor speed change rate, the actual torque of the motor and the torque required by the driver, and torque control is performed on the motor according to the first target motor torque.

Wherein in some embodiments, the first target motor torque is derived from the motor speed change rate, the motor actual torque, and the driver demand torque, comprising: determining a first motor torque change rate limit value according to the motor speed change rate; determining a second motor torque change rate limit value according to the actual torque of the motor; determining a third motor torque change rate limit value according to the difference value between the driver demand torque and the motor actual torque; and obtaining a first target motor torque according to the sum of the maximum value of the first motor torque change rate limiting value, the second motor torque change rate limiting value and the third motor torque change rate limiting value and the actual motor torque.

Specifically, as shown in fig. 2, fig. 2 is a schematic diagram of a negative zero-crossing process control method according to an embodiment of the present invention, wherein the change amount of the motor rotation speed in unit time is divided by the unit time to calculate the change rate of the motor rotation speed; filtering the calculated change rate of the motor rotation speed to avoid fluctuation of the change rate of the motor rotation speed; determining a first motor torque change rate limiting value according to the filtered motor speed change rate; determining a second motor torque change rate limiting value according to the received actual motor torque; subtracting the actual torque of the motor from the torque required by the driver to obtain a third motor torque change rate limiting value; since the torque of the negative zero crossing is changed from positive to negative and the torque change rate is negative, the maximum value of the change rate limiting values (i.e. the mode of the slowest change of the torque slope) is selected, and the maximum value is added with the actual torque of the motor to obtain the first target motor torque, as shown in fig. 3, and the control mode is characterized in that the motor speed change rate is used for controlling the motor torque change rate, and the control mode is characterized in that the motor speed change rate can quickly identify that the transmission line has entered a transmission direction switching stage, so that the control of the torque change slope is performed in advance.

Therefore, by setting two limiting thresholds, when the torque of the current wheel end falls in the interval of the limiting thresholds, the vehicle is judged to be in a negative zero-crossing interval, and the torque change slope is controlled according to the negative zero-crossing state, so that the torque change rate is reduced, vibration generated when the torque of the vehicle crosses zero is further reduced, and the influence of the zero-crossing state on the vehicle is reduced.

In order to facilitate those skilled in the art to further understand how to determine that the actual torque at the current wheel end is in the preset negative zero crossing, a detailed description will be given below with reference to specific embodiments.

As one possible implementation, in some embodiments, after determining that the current state is the driving state and the target state is the recycling state, further includes: judging whether the actual torque of the current wheel end is larger than a first preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a second preset torque threshold value or not, wherein the first preset torque threshold value is smaller than the second preset torque threshold value or not; and if the actual torque of the current wheel end is larger than the first preset torque threshold value and the actual torque of the current wheel end is smaller than the second preset torque threshold value, judging that the actual torque of the current wheel end is in a preset negative zero crossing interval.

It will be appreciated that when the actual torque at the wheel end changes from the driving state to the recovering state, that is, represents the process of converting the power transmission process from the motor-driven vehicle to the vehicle reverse towing motor, the actual torque at the wheel end will have an error in the converting process due to the difference between different vehicle models and configurations, and in order to eliminate the error, the embodiment of the present invention sets a first preset torque threshold value and a second preset torque threshold value, and when the actual torque at the wheel end falls within the threshold value range of the first preset torque threshold value and the second preset torque threshold value, it means that the actual torque at the current wheel end is within the preset negative zero-crossing interval.

Wherein, in some embodiments, before determining whether the current wheel end actual torque is greater than the first preset torque threshold and whether the current wheel end actual torque is less than the second preset torque threshold, the method further comprises: controlling the vehicle to be in a parking state, and acquiring a first actual torque when the motor rotating speed meets a first preset fluctuation condition and acquiring a second actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a first initial value to a first target value based on a first preset speed; and obtaining the second preset torque threshold according to the sum of the first actual torque and the first reserved torque, and obtaining the first preset torque threshold according to the difference between the second actual torque and the second reserved torque.

It will be appreciated that when the actual torque at the wheel end changes from the driven state to the recovered state, the motor speed fluctuates due to the presence of driveline lash and damping. The invention can determine the torque threshold value used for limiting the zero crossing interval by utilizing the fluctuation of the motor rotation speed, and the fluctuation of the motor rotation speed can be obviously observed when the change rate of the motor torque is lower, so the invention adopts a method for changing the motor torque at a slow rate, records the current motor torque when the fluctuation and the fluctuation zero trend occur to the motor for the first time, and calculates the sum value and the difference value of the motor torque at the two moments and the original reserved torque respectively to obtain the corrected preset torque threshold value.

Specifically, while the vehicle is in a park condition, embodiments of the present invention may manually control the drive motor torque to change from an initial set point (the torque being positive, e.g., 50 Nm) to a target set point (the torque being negative, e.g., -50 Nm) at a very small rate (e.g., -0.1 Nm/s). During this process, motor speed may fluctuate due to driveline lash and damping. When the motor rotation speed fluctuates for the first time, the actual torque of the motor at the moment plus the first reserved torque is a second preset torque threshold value; and when the motor rotation speed is completely static and has no fluctuation, subtracting the second reserved torque from the actual motor torque at the moment to obtain a first preset torque threshold. Therefore, when the actual torque of the current wheel end is larger than the first preset torque threshold value and smaller than the second preset torque threshold value, the actual torque of the current wheel end is in a preset negative zero crossing interval.

In addition, regarding the judgment and control method of the forward zero crossing state of the vehicle, the embodiments of the present application will be described in detail below.

Optionally, in some embodiments, after determining the target state and the current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque, further includes: and if the current state is the recovery state and the target state is the driving state, when the actual torque of the current wheel end is in a preset positive zero crossing interval, obtaining a second target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and controlling the torque of the motor according to the second target motor torque.

Specifically, when the actual torque of the wheel end is changed from the recovery state to the driving state, namely, the power transmission process is converted from the vehicle back-towing motor to the motor driving vehicle process, the vehicle is in a positive zero-crossing region, the motor rotation speed can fluctuate due to the existence of a transmission system clearance and damping, and the torque control of the motor is needed to be carried out for reducing the vibration among parts in the zero-crossing region. The invention obtains the second target motor torque through the motor rotation speed change rate, the motor actual torque and the driver demand torque, thereby controlling the motor torque.

Wherein in some embodiments, the second target motor torque is derived from the motor speed change rate, the motor actual torque, and the driver demand torque, comprising: determining a fourth motor torque change rate limiting value according to the motor speed change rate; determining a fifth motor torque change rate limiting value according to the actual torque of the motor; determining a sixth motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque; and obtaining a second target motor torque according to the sum value of the minimum value of the fourth motor torque change rate limiting value, the fifth motor torque change rate limiting value and the sixth motor torque change rate limiting value and the actual motor torque.

Specifically, as shown in fig. 4, fig. 4 is a schematic diagram of a forward zero-crossing process control method according to an embodiment of the present invention, wherein the change rate of the motor rotation speed is calculated by dividing the change amount of the motor rotation speed in unit time by the unit time; filtering the calculated change rate of the motor rotation speed to avoid fluctuation of the change rate of the motor rotation speed; determining a fourth motor torque change rate limiting value according to the filtered motor speed change rate; determining a fifth motor torque change rate limiting value according to the received actual motor torque; subtracting the actual torque of the motor from the torque required by the driver to obtain a sixth motor torque change rate limiting value; since the torque of the positive zero crossing is changed from negative to positive and the torque change rate is positive, the minimum value of the change rate limiting values (i.e. the mode that the torque slope is changed most slowly) is selected, and the second target motor torque is obtained by adding the minimum value and the actual motor torque.

Further, in some embodiments, after determining that the current state is the recovery state and the target state is the driving state, further comprising: judging whether the actual torque of the current wheel end is larger than a third preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a fourth preset torque threshold value or not, wherein the third preset torque threshold value is smaller than the fourth preset torque threshold value or not; and if the actual torque of the current wheel end is larger than the third preset torque threshold value and the actual torque of the current wheel end is smaller than the fourth preset torque threshold value, judging that the actual torque of the current wheel end is in a preset positive zero crossing interval.

It will be appreciated that when the actual torque at the wheel end changes from the recovery state to the drive state, i.e. represents a change in the power transmission process from the vehicle reverse motor to the motor driven vehicle process, an error in the actual torque at the wheel end during this change may occur due to differences between different vehicle models and configurations, and that for the purpose of eliminating this error the present embodiment provides a third preset torque threshold value and a fourth preset torque threshold value, wherein the third preset torque threshold value is less than the fourth preset torque threshold value. When the actual torque of the wheel end falls in the threshold range of the third preset torque threshold value and the fourth preset torque threshold value, the actual torque of the current wheel end is in the preset positive zero crossing interval.

Wherein, in some embodiments, before determining whether the current wheel end actual torque is greater than the third preset torque threshold and whether the current wheel end actual torque is less than the fourth preset torque threshold, the method further comprises: controlling the vehicle to be in a parking state, and acquiring a third actual torque when the motor rotating speed meets a second preset fluctuation condition and acquiring a fourth actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a second initial value to a second target value based on a second preset speed; and obtaining the third preset torque threshold according to the difference value of the third actual torque and the third reserved torque, and obtaining the fourth preset torque threshold according to the sum value of the fourth actual torque and the fourth reserved torque.

Specifically, the vehicle of the embodiment of the invention can control the driving motor torque to change from the initial set point (the torque is a negative value, for example, -50 Nm) to the target set point (the torque is a positive value, for example, -50 Nm) at a very small rate (for example, 0.1 Nm/s) while the vehicle is in a parking state. During this process, motor speed may fluctuate due to driveline lash and damping. When the motor rotation speed fluctuates for the first time, subtracting a third reserved torque from the actual torque of the motor at the moment to obtain a third preset torque threshold; and when the motor rotation speed is completely static and has no fluctuation, the actual torque of the motor and the fourth reserved torque at the moment are the fourth preset torque threshold value. Therefore, when the actual torque of the current wheel end is larger than the third preset torque threshold value and smaller than the fourth preset torque threshold value, the actual torque of the current wheel end is in a preset positive zero crossing interval.

In order for those skilled in the art to further understand the control method of the vehicle according to the embodiment of the present application, the following description will be provided in detail with reference to specific embodiments.

Specifically, as shown in fig. 5, the control method of the vehicle includes the steps of:

s501, driver intention judgment.

The driver demand torque is determined according to the driver's operation on the accelerator pedal opening.

S502, executing S503 if the current state is driving and the target state is recycling; if not, S505 is executed.

The current state is determined by the state of the actual torque of the current wheel end, and is a driving state when the actual torque is greater than or equal to zero and is a recovery state when the actual torque is less than zero. The target state is determined by the state of the driver's required torque, and is a driving state when the required torque is equal to or greater than zero, and is a recovery state when the required torque is less than zero.

S503, negative zero crossing interval judgment.

When the actual torque of the wheel end is changed from the driving state to the recovery state, namely, the power transmission process is converted from the motor-driven vehicle to the vehicle reverse-towing motor process. When the actual torque of the wheel end is smaller than the first preset torque threshold value and larger than the second preset torque threshold value, the wheel end is judged to enter a negative zero crossing interval

S504, negative zero crossing process control is performed, and S501 is returned after the negative zero crossing process control is finished.

And controlling the torque change process entering the negative zero crossing interval, returning to S501 after the control is finished, and waiting for the next zero crossing interval judgment.

S505, executing S506 if the current state is recycling and the target state is driving; if not, S508 is performed.

S506, judging the positive zero crossing interval.

When the actual torque at the wheel end is changed from the recovery state to the driving state, namely, the power transmission process is converted from the vehicle back-towing motor to the motor-driven vehicle process. And when the actual torque of the wheel end is larger than the third preset torque threshold value and smaller than the fourth preset torque threshold value, judging that the positive zero crossing interval is entered.

S507, forward zero crossing process control is finished, and S501 is returned to.

And controlling the torque change process entering the positive zero crossing interval, returning to S501 after the control is finished, and waiting for the next zero crossing interval judgment.

S508, ending.

According to the control method of the vehicle, the target state and the current state of the vehicle are determined according to the current accelerator pedal opening and the current wheel end actual torque by acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle; when the current state is judged to be a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, a first target motor torque is obtained according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and torque control is performed on the motor according to the first target motor torque. Therefore, through real-time judgment of the zero crossing interval and torque control of the motor, balance of power response speed and vehicle impact in the acceleration and deceleration process is achieved, drivability and smoothness of the whole vehicle are improved, and use experience of a user is improved.

Next, a control device of a vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Fig. 6 is a block schematic diagram of a control device of a vehicle according to an embodiment of the present invention.

As shown in fig. 6, the control device 10 of the vehicle includes: an acquisition module 100, a judgment module 200 and a control module 300.

The acquiring module 100 is configured to acquire a current accelerator pedal opening and a current wheel end actual torque of the vehicle;

a judging module 200, configured to determine a target state and a current state of the vehicle according to a current accelerator pedal opening and a current wheel end actual torque;

And the control module 300 is configured to obtain a first target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque when the current wheel end actual torque is in the preset negative zero crossing interval, and perform torque control on the motor according to the first target motor torque if the current state is the driving state and the target state is the recovery state.

According to one embodiment of the present invention, after determining that the current state is the driving state and the target state is the recovery state, the control module 300 is further configured to:

Judging whether the actual torque of the current wheel end is larger than a first preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a second preset torque threshold value or not, wherein the first preset torque threshold value is smaller than the second preset torque threshold value or not;

and if the actual torque of the current wheel end is larger than the first preset torque threshold value and the actual torque of the current wheel end is smaller than the second preset torque threshold value, judging that the actual torque of the current wheel end is in a preset negative zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the first preset torque threshold and whether the current wheel end actual torque is less than the second preset torque threshold, the control module 300 is further configured to:

controlling the vehicle to be in a parking state, and acquiring a first actual torque when the motor rotating speed meets a first preset fluctuation condition and acquiring a second actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of adjusting the torque of the motor from a first initial value to a first target value based on a first preset speed;

and obtaining a second preset torque threshold according to the sum of the first actual torque and the first reserved torque, and obtaining the first preset torque threshold according to the difference between the second actual torque and the second reserved torque.

According to one embodiment of the invention, the control module 300 is specifically configured to:

determining a first motor torque change rate limit value according to the motor speed change rate;

determining a second motor torque change rate limit value according to the actual torque of the motor;

Determining a third motor torque change rate limit value according to the difference value between the driver demand torque and the motor actual torque;

And obtaining a first target motor torque according to the sum of the maximum value of the first motor torque change rate limiting value, the second motor torque change rate limiting value and the third motor torque change rate limiting value and the actual motor torque.

According to one embodiment of the present invention, after determining the target state and the current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque, the judging module 200 includes:

And the forward zero crossing unit is used for obtaining a second target motor torque according to the motor speed change rate, the motor actual torque and the driver demand torque when the actual torque of the current wheel end is in a preset forward zero crossing interval if the current state is a recovery state and the target state is a driving state, and controlling the motor torque according to the second target motor torque.

According to one embodiment of the present invention, after determining that the current state is the recovery state and the target state is the driving state, the forward zero crossing unit is further configured to:

Judging whether the actual torque of the current wheel end is larger than a third preset torque threshold value or not, and the actual torque of the current wheel end is smaller than a fourth preset torque threshold value, wherein the third preset torque threshold value is smaller than the fourth preset torque threshold value;

And if the actual torque of the current wheel end is larger than the third preset torque threshold value and the actual torque of the current wheel end is smaller than the fourth preset torque threshold value, judging that the actual torque of the current wheel end is in a preset positive zero crossing interval.

According to one embodiment of the present invention, before determining whether the current wheel end actual torque is greater than the third preset torque threshold and whether the current wheel end actual torque is less than the fourth preset torque threshold, the positive zero crossing unit is further configured to:

Controlling the vehicle to be in a parking state, and acquiring a third actual torque when the motor rotating speed meets a second preset fluctuation condition and acquiring a fourth actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a second initial value to a second target value based on a second preset speed;

And obtaining a third preset torque threshold according to the difference value of the third actual torque and the third reserved torque, and obtaining a fourth preset torque threshold according to the sum value of the fourth actual torque and the fourth reserved torque.

According to one embodiment of the invention, the positive zero crossing unit is specifically configured to:

determining a fourth motor torque change rate limiting value according to the motor speed change rate;

determining a fifth motor torque change rate limiting value according to the actual torque of the motor;

Determining a sixth motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining a second target motor torque according to the sum value of the minimum value of the fourth motor torque change rate limiting value, the fifth motor torque change rate limiting value and the sixth motor torque change rate limiting value and the actual motor torque.

According to one embodiment of the present invention, the judging module 200 is specifically configured to:

judging whether the torque required by the driver is greater than or equal to a first preset value according to the current accelerator pedal opening;

if the driver demand torque is greater than or equal to a first preset value, judging the target state as a driving state, otherwise, judging the target state as a recovery state;

judging whether the actual torque of the current wheel end is smaller than a second preset value or not;

if the actual torque of the current wheel end is smaller than the second preset value, the current state is judged to be the recovery state, otherwise, the current state is judged to be the driving state.

According to the control device of the vehicle, the target state and the current state of the vehicle are determined according to the current accelerator pedal opening and the current wheel end actual torque by acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle; when the current state is judged to be a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, a first target motor torque is obtained according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and torque control is performed on the motor according to the first target motor torque. Therefore, through real-time judgment of the zero crossing interval and torque control of the motor, balance of power response speed and vehicle impact in the acceleration and deceleration process is achieved, drivability and smoothness of the whole vehicle are improved, and use experience of a user is improved.

Fig. 7 is a schematic structural diagram of a vehicle according to an embodiment of the present invention. The vehicle may include:

Memory 701, processor 702, and computer programs stored on memory 701 and executable on processor 702.

The processor 702 implements the control method of the vehicle provided in the above embodiment when executing a program.

Further, the vehicle further includes:

A communication interface 703 for communication between the memory 701 and the processor 702.

Memory 701 for storing a computer program executable on processor 702.

The memory 701 may include high-speed RAM (Random Access Memory ) memory, and may also include non-volatile memory, such as at least one disk memory.

If the memory 701, the processor 702, and the communication interface 703 are implemented independently, the communication interface 703, the memory 701, and the processor 702 may be connected to each other through a bus and perform communication with each other. The bus may be an ISA (Industry Standard Architecture ) bus, a PCI (PERIPHERAL COMPONENT INTERCONNECT, external device interconnect) bus, or EISA (Extended Industry Standard Architecture ) bus, among others. The buses may be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 7, but not only one bus or one type of bus.

Alternatively, in a specific implementation, if the memory 701, the processor 702, and the communication interface 703 are integrated on a chip, the memory 701, the processor 702, and the communication interface 703 may communicate with each other through internal interfaces.

The processor 702 may be a CPU (Central Processing Unit ) or an ASIC (Application SPECIFIC INTEGRATED Circuit, application specific integrated Circuit) or one or more integrated circuits configured to implement embodiments of the present invention.

The embodiment of the present invention also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the control method of a vehicle as above.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (10)

1. A control method of a vehicle, characterized by comprising the steps of:

Acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle;

Determining a target state and a current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque;

And if the current state is a driving state and the target state is a recovery state, when the actual torque of the current wheel end is in a preset negative zero crossing interval, obtaining a first target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by a driver, and controlling the torque of the motor according to the first target motor torque.

2. The method of claim 1, further comprising, after determining that the current state is the driving state and the target state is the recovery state:

judging whether the actual torque of the current wheel end is larger than a first preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a second preset torque threshold value or not, wherein the first preset torque threshold value is smaller than the second preset torque threshold value or not;

And if the current wheel end actual torque is larger than the first preset torque threshold value and the current wheel end actual torque is smaller than the second preset torque threshold value, judging that the current wheel end actual torque is in the preset negative zero crossing interval.

3. The method of claim 2, further comprising, prior to determining whether the current wheel end actual torque is greater than the first preset torque threshold and whether the current wheel end actual torque is less than the second preset torque threshold:

Controlling the vehicle to be in a parking state, and acquiring a first actual torque when the motor rotating speed meets a first preset fluctuation condition and acquiring a second actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a first initial value to a first target value based on a first preset speed;

and obtaining the second preset torque threshold according to the sum of the first actual torque and the first reserved torque, and obtaining the first preset torque threshold according to the difference between the second actual torque and the second reserved torque.

4. The method according to claim 1 or 2, wherein the obtaining the first target motor torque from the motor speed change rate, the motor actual torque, and the driver demand torque includes:

determining a first motor torque change rate limit value according to the motor speed change rate;

determining a second motor torque change rate limit value according to the actual motor torque;

Determining a third motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the first target motor torque according to the sum of the actual motor torque and the maximum value of the first motor torque change rate limiting value, the second motor torque change rate limiting value and the third motor torque change rate limiting value.

5. The method according to claim 1, characterized by further comprising, after determining the target state and the current state of the vehicle from the current accelerator pedal opening and the current wheel end actual torque:

And if the current state is the recovery state and the target state is the driving state, when the actual torque of the current wheel end is in a preset forward zero crossing interval, obtaining a second target motor torque according to the motor speed change rate, the actual torque of the motor and the torque required by the driver, and controlling the torque of the motor according to the second target motor torque.

6. The method of claim 5, further comprising, after determining that the current state is the recovery state and the target state is the drive state:

Judging whether the actual torque of the current wheel end is larger than a third preset torque threshold value or not, and whether the actual torque of the current wheel end is smaller than a fourth preset torque threshold value or not, wherein the third preset torque threshold value is smaller than the fourth preset torque threshold value;

and if the actual torque of the current wheel end is larger than the third preset torque threshold value and the actual torque of the current wheel end is smaller than the fourth preset torque threshold value, judging that the actual torque of the current wheel end is in the preset positive zero crossing interval.

7. The method of claim 6, further comprising, prior to determining whether the current wheel end actual torque is greater than the third preset torque threshold and whether the current wheel end actual torque is less than the fourth preset torque threshold:

Controlling the vehicle to be in a parking state, and acquiring a third actual torque when the motor rotating speed meets a second preset fluctuation condition and acquiring a fourth actual torque when the motor rotating speed is 0 and no fluctuation exists in the process of controlling the torque of the motor to be adjusted from a second initial value to a second target value based on a second preset speed;

And obtaining the third preset torque threshold according to the difference value of the third actual torque and the third reserved torque, and obtaining the fourth preset torque threshold according to the sum value of the fourth actual torque and the fourth reserved torque.

8. The method of claim 5 or 6, wherein the deriving the second target motor torque from the motor speed change rate, the motor actual torque, and the driver demand torque comprises:

determining a fourth motor torque change rate limiting value according to the motor rotation speed change rate;

determining a fifth motor torque change rate limit value according to the actual motor torque;

Determining a sixth motor torque change rate limit value according to the difference between the driver demand torque and the motor actual torque;

And obtaining the second target motor torque according to the sum of the actual motor torque and the minimum value of the fourth motor torque change rate limiting value, the fifth motor torque change rate limiting value and the sixth motor torque change rate limiting value.

9. The method of claim 1, wherein the determining the target state and the current state of the vehicle from the current accelerator pedal opening and the current wheel end actual torque comprises:

judging whether the torque required by the driver is larger than or equal to a first preset value according to the current accelerator pedal opening;

if the driver demand torque is greater than or equal to the first preset value, judging the target state as a driving state, otherwise, judging the target state as the recovery state;

judging whether the actual torque of the current wheel end is smaller than a second preset value or not;

And if the actual torque of the current wheel end is smaller than the second preset value, judging that the current state is the recovery state, otherwise, judging that the current state is the driving state.

10. A control device for a vehicle, comprising:

the acquisition module is used for acquiring the current accelerator pedal opening and the current wheel end actual torque of the vehicle;

The judging module is used for determining a target state and a current state of the vehicle according to the current accelerator pedal opening and the current wheel end actual torque;

and the control module is used for obtaining a first target motor torque according to the motor rotation speed change rate, the motor actual torque and the driver demand torque when the current wheel end actual torque is in a preset negative zero crossing interval and controlling the motor torque according to the first target motor torque if the current state is a driving state and the target state is a recovery state.