CN102509887A - Servo system for tracking moving target by linear variable-coefficient servo driving radar antenna - Google Patents

Abstract

The invention provides a servo system for tracking a moving target by a linear variable-coefficient servo driving radar antenna. A servo controller consists of a position error selector, a position corrector, a speed corrector, a current corrector, a power amplifying element and an execution mechanism which are connected in series with one another; current of a motor is fed back by a Hall sensor to form a current loop of the servo system, and speed of the motor is fed back by a speed measurer coaxial with the motor to form a speed loop of the servo system; an antenna position is fed back by a position detection element coaxial with the radar antenna to a target position detector to form a position loop of the servo system; a circuit of the servo controller comprises a digital signal processor (DSP) and a field programmable gate array (FPGA) which are connected with each other through an address bus and a data bus; the built-in linear equation variable-coefficient operation of the DSP and the operation treatment of the three loops controls the motor to drive the antenna to run; and the FPGA exchanges data with the DSP through a programmed decoding circuit, and transmits and receives serial communication interface (SCI) data. According to the servo system, the radar tracking error can be reduced quickly, and the radar tracking precision is improved.

Description

The servo system of linear variable coefficient servo-drive radar antenna pursuit movement target

Technical field

The present invention relates to a kind of servo system of linear variable coefficient servo-drive radar antenna pursuit movement target.

Background technology

Three closed loop calculation process and controls of the electric current loop of tracking radar servo system, speed ring, position ring at present; Normal PID (ratio, integration, differential) the control and treatment algorithm that adopts classical Theory of Automatic Control design current, speed, position three closed loops also often is to use traditional fixed proportion coefficient or segmentation scales coefficient correction method for site error.Adopt above-mentioned prior art tracking small-signal error responses speed slow, tracking lag easily, systematic tracking accuracy is relatively poor, and tracking large-signal error responses speed is fast, follows the tracks of overshoot easily, the radar tracking poor stability.

Summary of the invention

The present invention is directed to the weak point that above-mentioned technology exists, provide a kind of stability high, cost is low, can effectively improve radar measurement accuracy, and has the linear variable coefficient servo drive system of fast response characteristic, high tracking accuracy.

Above-mentioned purpose of the present invention reaches through following measure.A kind of servo system of linear variable coefficient servo-drive radar antenna pursuit movement target; Comprise servo controller and servounit structure; It is characterized in that: said servo controller is made up of the site error Chooser, position correction device, velocity correction device, current correction device, power amplification element and the actuator that are series at successively between servounit structure and the object position detector; Said actuator is a motor; The current feedback of motor forms the electric current loop of servo system through the current Hall transducer; The speed feedback of motor is through forming the speed ring of servo system with the tachometer of motor coaxle running, the position of radar antenna through and the coaxial position detecting element of radar antenna feed back to the position ring that object position detector forms servo system, totally three loops; In the servo controller circuit; Contain the digital signal processor (DSP) and the field programmable gate array (FPGA) that link to each other with data/address bus through address bus; DSP is through the magnification ratio coefficient of the linear equation variable coefficient work location ring error of plug-in software; Above-mentioned three loops to servo controller control carry out calculation process and control, and the output control signal drives above-mentioned driven by motor radar antenna running, and the target of motion is followed the tracks of; FPGA carries out exchanges data through the decoding circuit and the DSP of programming, and realizes the transmission and the reception of multi-path asynchronous string shape communication interface (SCI) data.

The present invention has following beneficial effect than prior art.

The present invention adopts the dsp software programming technique to realize three closed loop calculation process and controls of the electric current loop of tracking radar servo system, speed ring, position ring; The magnification ratio coefficient of error is changed in certain scope internal linear; DSP carries out calculation process and control to servo-controlled three loops (electric current loop, speed ring, position ring); The output control signal, through power amplification, drive motors drives the radar antenna running; Utilize programmable gate array and the embedded programming technology of FPGA; The transmission and the reception of multichannel SCI data have been realized; And, realize seamless link through data/address bus and address bus mode between FPGA and the DSP by the I/O that FPGA realizes other peripheral interface signal.In the control calculation process; The error of position ring does not re-use traditional fixed proportion or segmentation scales bearing calibration; But adopted linear equation variable coefficient mode, and the proportionality coefficient of error is changed in certain scope internal linear, high tracking accuracy is tracking target apace.

The present invention adopts three closed loop Comprehensive Control Technology, DSP+FPGA embedded technology, PWM (pulse width modulation) power drive technology; Through position ring error linear equation variable coefficient mode, make the magnification ratio coefficient of position ring error in restricted portion, be linear variation, make that error hour proportionality coefficient is big; Eliminate little error apace; When error was big, proportionality coefficient diminished linearly, produced overshoot when avoiding mistake.Error hour so linearly becomes big proportionality coefficient, makes and can reflect apace that to little error proportionality coefficient was little when error was big, and mistake is unlikely to overshoot again, can reduce the radar tracking error apace, improves radar tracking precision.Because DSP has only one road SCI asynchronous serial port; But servo controller need realize that SCI communicates by letter with a plurality of peripheral hardwares, and the programmable logic functions that FPGA is powerful can realize many serial ports expansion, has saved chip and circuit board space; Reduce hardware cost, increased maintainability and design flexibility.The stability of a system is high, and cost is low, can effectively improve radar measurement accuracy 10%, satisfies measuring and controlling equipment precision tracking requirement.

Through certain vehicular pulse instrumentation radar check, verified the situation up to standard of technical indicator and function.The present invention can be applicable to precision tracking radar servo-drive, drives radar antenna precision tracking moving target.

Description of drawings

Below, in conjunction with accompanying drawing and execution mode the present invention is further specified.

Fig. 1 is a radar servo-control system block diagram of the present invention.

It in Fig. 2 frame of broken lines the electric theory diagram of radar servo-control system.

Fig. 3 is the linearity curve graph of a relation between site error of the present invention and the proportionality coefficient.

Embodiment

Consult Fig. 1.Radar servo system is divided into servo controller and servounit structure two large divisions.Servo controller is made up of site error Chooser, position correction device, velocity correction device, current correction device, power amplification element, the actuator of series connection successively.Contain digital signal processor shown in Figure 2 (DSP) and field programmable gate array (FPGA) in the servo controller circuit of radar servo system; The calculation process and the control of the electric current loop of DSP realization servo system, speed ring, three loops of position ring; FPGA realizes transmission and the I/O of reception and other peripheral interface signal of the multichannel SCI data of servo system, and and DSP between carry out exchanges data through data/address bus and address bus mode.The pulse width modulating signal (PWM) of DSP output amplifies through power amplification element, and drive motors drives the radar antenna running, follows the motion of target, realizes precision tracking.

The current feedback of actuator's motor forms the speed ring of servo system through the electric current loop of Hall current sensor sampling formation servo system, the speed feedback of actuator's motor through the tachometer with the motor coaxle running; The position feedback of radar antenna feeds back to the position ring that the target location ring forms servo system, totally three loops through the position detecting element with the coaxial running of radar antenna.Electric current loop is the high interior ring of response frequency, and position ring is the low outer shroud of response frequency.The Hall current sensor that the electric current of servo controller actuator motor passes through is taken a sample and is proofreaied and correct input parameter through negative feedback after operational amplifier amplification, the filtering as electric current loop; The speed of motor tests the speed through tachometer and amplification, filtering after negative feedback as the velocity correction input parameter; The current location of radar antenna is through the input of position sensor feedback to position ring; Site error between target location and the radar antenna position is as the input parameter of position ring; This input parameter is carried out linear variable coefficient treatment for correcting and filtering; Make the magnification ratio coefficient of position ring error in certain scope, be linear change, with the input parameter of the data output after handling as speed ring; The output parameter of speed ring is as the input parameter of electric current loop.

Consult Fig. 2.In the circuit theory of the servo controller of in frame of broken lines, describing, the AC power of 220V/50Hz becomes high voltage source through the rectifying and wave-filtering of current rectifying and wave filtering circuit.High voltage source is used for power driving power supply, and low-tension supply is given the low-voltage circuit power supply of servo controller.In described servo controller circuit, contain the digital signal processor (DSP) and the field programmable gate array (FPGA) that link to each other with data/address bus through address bus; DSP is the core devices of servo controller; Realize the calculation process and the control of three loops of servo controller; FPGA is the interface device of servo controller, realize external input/output interface and and DSP between exchanges data.The Hall element current detecting that links to each other with motor; The detection voltage of tachometer is through behind the testing circuit of servo controller; Gather through A/D again and deliver to FPGA; Read through data/address bus by DSP,, participate in the calculation process of DSP internal processes respectively as the negative feedback of electric current loop and the negative feedback of speed ring.Be connected in the position detecting element between servounit structure and the FPGA,, receive buffer memory, read through data/address bus, as the parameter input of position ring by DSP through FPGA with the radar antenna position signalling that detects.DSP controls and computing according to the operating state of radar, and output pwm signal is given power amplification circuit, and drive motors actuator drives the radar antenna running.

Drive for stablizing actuator's power of motor; The influence of level and smooth load torque fluctuation; Raising system control stability; The electric current of actuator's motor obtains and the linearly proportional voltage of current of electric through the Hall current sensor on the servo controller circuit board, the input of Current Negative Three-Point Capacitance to electric current loop;

Disturbance ability for the anti-load of raising system; The control system stabilization of speed; Improve system stiffness; The harmful effect of various non-linear factors in reducing to encircle, the speed of actuator's motor obtains the linearly proportional voltage of speed with motor, the input of negative velocity feedback to speed ring through the tachometer with motor coaxle running;

For improving the alliance control precision, the position of radar antenna feeds back to the input of position ring through the position detecting element of servo controller.DSP adopts linear equation variable coefficient mode that site error is handled and filtering; Make the magnification ratio coefficient of position ring error in certain scope, be linear variation, employing ratio, integration, differential (PID) mode are carried out treatment for correcting to speed ring, and employing ratio, integration (PI) mode are carried out treatment for correcting to electric current loop; And in the DSP sheet, accomplish the regeneration feedback of radar servo system, the calculation process of azimuthal error secant compensation simultaneously; Obtain final control output variable, output pwm signal amplifies through power amplification element, and drive motors drives the radar antenna running; Follow the motion of target, realize precision tracking.Servo controller communicates by letter with the SCI of a plurality of peripheral hardwares, external other input, output signal; Realize by FPGA with programmable logic functions; Realize the I/O of many serial ports expansion and signal through logic programming language, and with the decoding circuit realization exchanges data of DSP through address bus and data/address bus, FPGA programming.

Consult Fig. 3.Site error and error ratio linearity curve relation show that error is in restricted portion, and the magnification ratio coefficient of error is not a definite value; But satisfy curved line relation shown in Figure 3, and the sum of errors proportionality coefficient is the inversely proportional linear relationship, error is more little; Proportionality coefficient is big more; Error is big more, and proportionality coefficient is more little, can be expressed as with formula:

$K_p=K_{p0}-(K_{p0}-K_{p1})\×\frac{\left|\mathrm{err}\right|}{\max }\·\·\·\·\·\·\left(1\right)$

Wherein:

K _P0Be the worst error proportionality coefficient

K _P1Be the minimal error proportionality coefficient

Max is the maximum position error

Err is a deviations of actual position

Can guarantee that so quick tracking of little error puts in place, the raising tracking accuracy, not overshoot of mistake improves stability, thus the tracking accuracy of raising radar servo system and quick reflection ability.

Claims (8)

1. the servo system of a linear variable coefficient servo-drive radar antenna pursuit movement target; Comprise servo controller and servounit structure; It is characterized in that: said servo controller is made up of the site error Chooser, position correction device, velocity correction device, current correction device, power amplification element and the actuator that are series at successively between servounit structure and the object position detector; Said actuator is a motor; The current feedback of motor forms the speed ring of servo system through the electric current loop of current Hall transducer formation servo system, the speed feedback of motor through the tachometer with the motor coaxle running; The position of radar antenna is through feeding back to the position ring that object position detector forms servo system, totally three loops with the coaxial position detecting element of radar antenna; In the servo controller circuit; Contain the digital signal processor (DSP) and the field programmable gate array (FPGA) that link to each other with data/address bus through address bus; DSP is through the magnification ratio coefficient of the linear equation variable coefficient work location ring error of plug-in software; The output control signal drives above-mentioned driven by motor radar antenna running, and the target of motion is followed the tracks of, and above-mentioned three loops that servo controller is controlled carry out calculation process and control; FPGA carries out exchanges data through the decoding circuit and the DSP of programming, and realizes the transmission and the reception of multi-path asynchronous string shape communication interface (SCI) data.

2. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1 is characterized in that: electric current loop is the high interior ring of response frequency, and position ring is the low outer shroud of response frequency.

3. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1; It is characterized in that: the electric current of servo controller actuator motor is taken a sample through Hall current sensor, and proofreaies and correct input parameter through negative feedback after operational amplifier amplification, the filtering as electric current loop; The speed of motor tests the speed through tachometer and amplification, filtering after negative feedback as the velocity correction input parameter.

4. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1 is characterized in that: the current location of radar antenna is through the input of position sensor feedback to position ring; Site error between target location and the radar antenna position is as the input parameter of position ring; This input parameter is carried out linear variable coefficient treatment for correcting and filtering; Make the magnification ratio coefficient of position ring error in certain scope, be linear change, with the input parameter of the data output after handling as speed ring; The output parameter of speed ring is as the input parameter of electric current loop.

5. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1; It is characterized in that: be connected in the position detecting element between servounit structure and the FPGA; With detected radar antenna position signalling; Receive buffer memory through FPGA, read through data/address bus, as the parameter input of position ring by DSP.

6. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1; It is characterized in that: the electric current of actuator's motor obtains and the linearly proportional voltage of current of electric through the Hall current sensor on the servo controller circuit board, the input of Current Negative Three-Point Capacitance to electric current loop.

7. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1; It is characterized in that: the speed of actuator's motor obtains the linearly proportional voltage of speed with motor, the input of negative velocity feedback to speed ring through the tachometer with motor coaxle running.

8. the servo system of linear variable coefficient servo-drive radar antenna pursuit movement target according to claim 1, it is characterized in that: site error and proportionality coefficient are the inversely proportional linear relationship, are formulated as:

$K_p=K_{p0}-(K_{p0}-K_{p1})\×\frac{\left|\mathrm{err}\right|}{\max }\·\·\·\·\·\·\left(1\right)$

Wherein: K _P0Be worst error proportionality coefficient, K _P1Be the minimal error proportionality coefficient, max is the maximum position error, and err is a deviations of actual position.

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