CN112904764B - A space rendezvous and docking laser radar scanning tracking control system and method - Google Patents

Abstract

The invention discloses a space intersection docking laser radar scanning tracking control system and a space intersection docking laser radar scanning tracking control method. A closed-loop control system is established by utilizing a single-chip DSP, and the movement direction and the frequency division coefficient of the two stepping motors are determined according to the azimuth axis angle value, the pitching axis angle value and the two-dimensional off-target quantity. Adopting a single-chip FPGA to realize the subdivision driving of the pitch axis stepping motor SPWM and the azimuth axis stepping motor SPWM, and generating pitch axis SPWM waves and azimuth axis SPWM waves according to the motion directions and the frequency division coefficients of the two stepping motors; and 4 bipolar H bridge power driving circuits are utilized to amplify the pitching axis SPWM wave and the azimuth axis SPWM wave, and then the two stepping motors are respectively controlled to drive the azimuth axis and the pitching axis to rotate so as to drive the four-quadrant detector to scan and track. According to the invention, the azimuth axis and the pitching axis subdivision driving and closed-loop control based on the stepping motor are realized by adopting the single-chip DSP and the FPGA, and the required control function and performance index are realized under the condition that no additional control chip or sensor is added, so that the circuit and the structure are simplified, and the requirement of space application is met.

Description

A space rendezvous and docking laser radar scanning tracking control system and method

technical field

The invention relates to the technical field of scanning and tracking control, in particular to a scanning and tracking control system and method for space rendezvous and docking laser radar.

Background technique

In space rendezvous and docking, lidar is a major measurement device. The working principle of the laser radar is: the laser sends a single pulse laser (that is, the main wave), and the laser returns to the original path after hitting the cooperative target; the detector receives the laser echo, measures the time difference between the main wave and the echo, and calculates the straight-line distance from the target to the radar. According to the azimuth and elevation angles emitted by the laser, combined with the straight-line distance, the position of the target in the polar coordinate system centered on the radar is obtained.

Due to the strong directivity of the laser, the divergence angle of the beam and the acceptance angle of the detector are both on the order of milliradians, and the detection range of a pulse laser emission is extremely limited. In order to scan and capture the target in a wide range, and then enter the stable tracking state to measure the distance and angle of the target, it must cooperate with the motion control of the azimuth axis and the pitch axis.

At present, DC motors, permanent magnet synchronous motors and other control methods are used to control the azimuth and pitch two-axis motion control of the laser radar. DC motors and permanent magnet synchronous motors can provide superior torque and response characteristics, but they are also more complicated to control. To achieve high-precision motion control for DC motors and permanent magnet synchronous motors, three-loop control is generally used. The inner current loop requires the use of dedicated current sensors to achieve current closed-loop, and the volume, weight, and complexity of the system increase accordingly. There are brushes in the DC motor, and electric sparks may be generated during the commutation process. At the same time, the brushes will wear and generate redundant products, and the life of the system will be limited. The reliability does not meet the needs of space applications. Permanent magnet synchronous motors do not have the problem of brushes, but the control is more complicated. Permanent magnet synchronous motors are generally three-phase, which requires real-time measurement of two-phase currents, and undergoes relatively complex transformation and calculation, which requires higher computing power of DSP. During the motion of the DC motor and the permanent magnet synchronous motor, the acceleration is different, the output torque changes greatly, and the impact on the power supply is also large. Therefore, the existing two-axis control system is relatively complicated to control, high in cost, heavy in weight, and has problems of space environment adaptability.

Contents of the invention

Based on this, the object of the present invention is to provide a space rendezvous and docking laser radar scanning and tracking control system and method, which can reduce system cost and weight and improve system reliability while meeting accuracy requirements.

In order to achieve the above object, the present invention provides a space rendezvous and docking lidar scanning and tracking control system, the system includes:

An angle sensor is used to detect the angle value of the azimuth axis and the angle value of the pitch axis;

The four-quadrant detector is used to determine the two-dimensional miss amount according to the energy of the echo in each quadrant;

The DSP closed-loop controller is connected with the angle sensor and the four-quadrant detector respectively, and is used to determine the direction of motion and the frequency division coefficient of two stepper motors according to the angle value of the azimuth axis, the angle value of the pitch axis and the two-dimensional miss amount; the direction of motion of the two stepper motors includes: the direction of motion of the pitch motor and the direction of motion of the azimuth motor; the frequency division coefficient of the two stepper motors includes the frequency division coefficient of the pitch motor and the frequency division coefficient of the azimuth motor;

A SPWM subdivision drive controller, connected with the DSP closed-loop controller, is used to determine the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepper motors;

4 bipolar H-bridge power drive circuits are respectively connected with the SPWM subdivision drive controller and two stepping motors, and are used to amplify the first SPWM wave and the second SPWM wave and then control the two stepping motors respectively, so that the two stepping motors drive the rotation of the azimuth axis and the pitch axis respectively, and then drive the four-quadrant detector to scan and track; the two stepper motors are respectively an azimuth motor and a pitch motor.

Optionally, the SPWM subdivision drive controller includes:

The system clock is used to generate a clock signal;

A pitch axis stepping pulse generator, connected to the DSP closed-loop controller and the system clock respectively, for determining a first stepping pulse according to the frequency division factor of the pitching motor and the clock signal;

The first counter is respectively connected with the DSP closed-loop controller, the system clock and the pitch axis step pulse generator, and is used to count according to the motion direction of the pitch motor and the first step pulse to obtain a first count value;

The first table look-up module is connected to the first counter, and is used to determine the pitch axis SIN value by looking up the pitch axis SIN table according to the first count value;

The second table look-up module is connected to the first counter, and is used to determine the pitch axis COS value by looking up the pitch axis COS table according to the first count value;

An azimuth axis stepping pulse generator is connected with the DSP closed-loop controller and the system clock respectively, and is used to determine the second stepping pulse according to the frequency division factor of the azimuth motor and the clock signal;

The second counter is connected with the DSP closed-loop controller, the system clock and the azimuth axis step pulse generator respectively, and is used to count according to the movement direction of the azimuth motor and the second step pulse to obtain a second count value;

The third table look-up module is connected to the second counter, and is used to determine the azimuth axis SIN value by searching the azimuth axis SIN table according to the second count value;

The fourth table look-up module is connected with the second counter, and is used to determine the azimuth axis COS value by searching the azimuth axis COS table according to the second count value;

A carrier counter, connected to the system clock, is used to count the carrier of the clock signal to obtain the carrier value;

The translation correction module is respectively connected with the first table look-up module, the second table look-up module, the third table look-up module and the fourth table look-up module, and is used to perform translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value and the azimuth axis COS value;

The first comparator is connected to the carrier counter and the translation correction module respectively, and is used to compare the carrier value with the corrected pitch axis SIN value to obtain a phase A SPWM wave of the pitch motor;

The second comparator is respectively connected to the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected COS value of the pitch axis to obtain a B-phase SPWM wave of the pitch motor; the first SPWM wave includes a pitch motor A-phase SPWM wave and a pitch motor B-phase SPWM wave;

The third comparator is respectively connected with the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected azimuth axis SIN value to obtain the A-phase SPWM wave of the azimuth motor;

The fourth comparator is respectively connected with the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected azimuth axis COS value to obtain the B-phase SPWM wave of the azimuth motor; the second SPWM wave includes the A-phase SPWM wave of the azimuth motor and the B-phase SPWM wave of the azimuth motor.

Optionally, the four bipolar H-bridge power drive circuits are:

A-phase winding drive circuit for azimuth motor, B-phase winding drive circuit for azimuth motor, A-phase winding drive circuit for pitch motor, and B-phase winding drive circuit for pitch motor;

The A-phase winding drive circuit of the azimuth motor includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an A-phase winding of the azimuth motor; the first end of the first switch tube and the first end of the third switch tube are respectively connected to the positive pole of the driving power supply; the third end of the first switch tube is respectively connected to the first end of the second switch tube and one end of the A-phase winding of the azimuth motor; The third end of the second switching tube is connected to the negative pole of the driving power supply respectively, the second end of the first switching tube and the second end of the fourth switching tube are respectively connected to the A-phase SPWM wave of the azimuth motor output by the first comparator, and the second end of the second switching tube and the second end of the third switching tube are respectively connected to the inverted signal of the A-phase SPWM wave of the azimuth motor output by the first comparator;

The B-phase winding drive circuit of the azimuth motor includes a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, and a B-phase winding of the azimuth motor; the first end of the fifth switch tube and the first end of the seventh switch tube are respectively connected to the positive pole of the driving power supply; the third end of the fifth switch tube is respectively connected to the first end of the sixth switch tube and one end of the B-phase winding of the azimuth motor; The third end of the third switch tube and the third end of the sixth switch tube are respectively connected to the negative pole of the driving power supply, the second end of the fifth switch tube and the second end of the eighth switch tube are respectively connected to the B-phase SPWM wave of the azimuth motor output by the second comparator, and the second end of the sixth switch tube and the second end of the seventh switch tube are respectively connected to the reversed signal of the B-phase SPWM wave of the azimuth motor output by the second comparator;

The A-phase winding drive circuit of the pitch motor includes a ninth switch tube, a tenth switch tube, an eleventh switch tube, a twelfth switch tube, and a pitch motor A-phase winding; the first end of the ninth switch tube and the first end of the eleventh switch tube are respectively connected to the positive pole of the driving power supply; the third end of the ninth switch tube is connected to the first end of the twentieth switch tube and one end of the A-phase winding of the pitch motor; connected, the third end of the twelfth switching tube and the third end of the tenth switching tube are respectively connected to the negative pole of the driving power supply, the second end of the ninth switching tube and the second end of the twelfth switching tube are respectively connected to the A-phase SPWM wave of the pitch motor output by the third comparator, and the second end of the tenth switching tube and the second end of the eleventh switching tube are respectively connected to the inverted signal of the pitch motor A-phase SPWM wave output by the third comparator;

The pitch motor B-phase winding driving circuit includes a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube, a sixteenth switch tube, and a pitch motor B-phase winding; the first end of the thirteenth switch tube and the first end of the fifteenth switch tube are respectively connected to the positive pole of the driving power supply; the third end of the thirteenth switch tube is connected to the first end of the fourteenth switch tube and one end of the B-phase winding of the pitch motor; The third end of the sixteenth switching tube and the third end of the fourteenth switching tube are respectively connected to the negative pole of the driving power supply, the second end of the thirteenth switching tube and the second end of the sixteenth switching tube are respectively connected to the B-phase SPWM wave of the pitch motor output by the fourth comparator, and the second end of the fourteenth switching tube and the second end of the fifteenth switching tube are respectively connected to the inverted signal of the B-phase SPWM wave of the pitch motor output by the fourth comparator.

Optionally, the system also includes:

The photoelectric isolation circuit is arranged between the SPWM subdivision drive controller and the four bipolar H-bridge power drive circuits, and is used for optocoupler isolation of the first SPWM wave and the second SPWM wave.

Optionally, the system also includes:

Eight power drive chips are arranged between the photoelectric isolation circuit and the four bipolar H-bridge power drive circuits, and are used to respectively drive the A-phase winding drive circuit of the azimuth motor, the B-phase winding drive circuit of the azimuth motor, the A-phase winding drive circuit of the pitch motor, and the B-phase winding drive circuit of the pitch motor.

Optionally, the model of the power driver chip is IR2110.

Optionally, when the first switching tube, the second switching tube, the third switching tube, the fourth switching tube, the fifth switching tube, the sixth switching tube, the seventh switching tube, the eighth switching tube, the ninth switching tube, the tenth switching tube, the eleventh switching tube, the twelfth switching tube, the thirteenth switching tube, the fourteenth switching tube, the fifteenth switching tube and the sixteenth switching tube are all MOS tubes, the first terminal is the drain, the second terminal is the gate, and the third terminal is the source.

The present invention also provides a space rendezvous and docking lidar scanning and tracking control method, the method comprising:

Use the angle sensor to obtain the angle value of the azimuth axis and the angle value of the pitch axis;

Determine the two-dimensional off-target amount according to the energy of the echo in each quadrant;

According to the angle value of the azimuth axis, the angle value of the pitch axis and the two-dimensional miss amount, the direction of motion and the frequency division coefficient of the two stepper motors are determined; the direction of motion of the two stepper motors includes: the direction of motion of the pitch motor and the direction of motion of the azimuth motor; the frequency division coefficients of the two stepper motors include the frequency division coefficient of the pitch motor and the frequency division coefficient of the azimuth motor;

Determine the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepper motors;

After amplifying the first SPWM wave and the second SPWM wave, respectively control two stepping motors, so that the two stepping motors drive the azimuth axis and the pitch axis to rotate respectively, and then drive the four-quadrant detector to scan and track; the two stepping motors are respectively an azimuth motor and a pitch motor.

Optionally, the determining the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepping motors specifically includes:

get clock signal;

determining a first step pulse according to the frequency division factor of the pitch motor and the clock signal;

Counting according to the motion direction of the pitch motor and the first step pulse to obtain a first count value;

Determine the pitch axis SIN value by looking up the pitch axis SIN table according to the first count value;

Determine the pitch axis COS value by looking up the pitch axis COS table according to the first count value;

Perform carrier counting on the clock signal to obtain the carrier value;

determining a second stepping pulse according to the frequency division factor of the azimuth motor and the clock signal;

Counting according to the moving direction of the azimuth motor and the second stepping pulses to obtain a second count value;

Determine the azimuth axis SIN value by searching the azimuth axis SIN table according to the second count value;

determining the azimuth axis COS value by searching the azimuth axis COS table according to the second count value;

Perform translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value and the azimuth axis COS value;

Comparing the carrier value with the corrected pitch axis SIN value to obtain a phase A SPWM wave of the pitch motor;

Comparing the carrier value with the corrected COS value of the pitch axis to obtain the B-phase SPWM wave of the pitch motor; the first SPWM wave includes the A-phase SPWM wave of the pitch motor and the B-phase SPWM wave of the pitch motor;

The carrier value is compared with the corrected azimuth axis SIN value to obtain the A-phase SPWM wave of the azimuth motor;

The carrier value is compared with the corrected COS value of the azimuth axis to obtain the B-phase SPWM wave of the azimuth motor; the second SPWM wave includes the A-phase SPWM wave of the azimuth motor and the B-phase SPWM wave of the azimuth motor.

According to the specific embodiments provided by the invention, the invention discloses the following technical effects:

The invention is based on the high-precision SPWM subdivision drive closed-loop system of the stepping motor, constructs the closed-loop controller with a single-chip DSP, uses the angle sensor and the off-target amount of the four-quadrant detector as double feedback, and realizes high-speed scanning control and stable tracking control of the two-axis stepping motor at the same time. The SPWM subdivision drive controller is implemented with a single FPGA, and the required control functions and performance indicators are realized without adding additional control chips and sensors, which simplifies the circuit and structure, improves system reliability, and meets the needs of space rendezvous and docking applications.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative work.

Fig. 1 is a structural diagram of a space rendezvous and docking lidar scanning and tracking control system according to an embodiment of the present invention;

Fig. 2 is the step angle subdivision principle of the two-phase hybrid stepper motor according to the embodiment of the present invention;

Fig. 3 is the structural diagram of the SPWM subdivision drive controller of the embodiment of the present invention;

Fig. 4 is a structural diagram of a phase A winding drive circuit of an azimuth motor according to an embodiment of the present invention;

Among them, 1. Angle sensor, 2. DSP closed-loop controller, 3. SPWM subdivision drive controller, 4. Bipolar H-bridge power drive circuit, 5. Four-quadrant detector, 6. Pitch motor, 7. Azimuth motor.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The purpose of the present invention is to provide a space rendezvous and docking laser radar scanning tracking control system and method, which can reduce system cost and weight and improve system reliability while meeting the precision requirements.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a structural diagram of a space rendezvous and docking laser radar scanning and tracking control system according to an embodiment of the present invention. As shown in Fig. 1 , the present invention discloses a space rendezvous and docking laser radar scanning and tracking control system. The system includes: an angle sensor 1, a four-quadrant detector 5, a DSP closed-loop controller 2, a SPWM subdivision drive controller 3, and four bipolar H-bridge power drive circuits 4; the DSP closed-loop controller 2 is connected to the angle sensor 1 and the four-quadrant detector 5 respectively; A bipolar H-bridge power drive circuit 4 is connected with the SPWM subdivision drive controller 3 and two stepper motors respectively.

Described angle sensor 1 is used for detecting azimuth axis angle value and pitch axis angle value; Described four-quadrant detector 5 is used for determining the two-dimensional off-target amount according to the energy of echo in each quadrant; Described DSP closed-loop controller 2 is used for determining the motion direction and the frequency division coefficient of two stepper motors according to the described azimuth axis angle value, the described pitch axis angle value and the described two-dimensional off-target amount; the motion direction of two stepper motors comprises: the motion direction of pitch motor 6 and the motion direction of azimuth motor 7; frequency coefficient and the frequency division coefficient of the azimuth motor 7; the SPWM subdivision drive controller 3 is used to determine the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepper motors; the four bipolar H-bridge power drive circuits 4 are used to amplify the first SPWM wave and the second SPWM wave to control the two stepper motors respectively, so that the two stepper motors drive the azimuth axis and the pitch axis to rotate respectively, and then drive the four-quadrant detector 5 to scan and track; Lift up the motor6.

The closed-loop controller in the present invention is designed based on DSP. The DSP is an aerospace-grade high-reliability product, and the closed-loop control function is completed in combination with a control algorithm. In the scanning state, a closed loop is performed according to the angle value of the azimuth axis and the angle value of the pitch axis detected by the angle sensor 1 to complete the control of large-scale high-speed scanning motion. In the tracking state, a closed loop is performed according to the two-dimensional off-target amount output by the four-quadrant detector 5 to realize stable tracking control. DSP outputs the motion direction and frequency division coefficient of the two-axis stepping motor as the control quantity. The frequency division factor determines the movement speed of the stepper motor.

The working principle of SPWM subdivision drive controller 3 is explained as follows:

The stepper motor used in space rendezvous and docking lidar is a two-phase hybrid stepper motor. The hybrid stepper motor has the advantages of high operating frequency, large dynamic torque, small fluctuation, stable operation, low noise, high positioning accuracy and resolution. The two-phase hybrid stepping motor has two-phase windings, which are arranged with a 90° difference in space. The phase currents pass through the two-phase windings according to a certain sequence to generate continuously changing torque and drive the rotor to rotate.

In the drive circuit without subdivision, the phase current works in the switch state, and the current in the winding is 0 or the positive and negative rated value. Assume that the two-phase windings are A-phase and B-phase respectively, the torque generated by the positive rated current of the A-phase winding is T _A+ , the negative rated current torque is T _A- , and the B-phase winding torques are T _B+ and T _B- . A, B phase winding torque is equal. Taking the single four-beat working mode as an example, the torque change is shown in Figure 2(a), the rotor moves 1/4 of the tooth pitch per beat, and the torque is constant.

Subdividing the step angle of the stepping motor is realized by changing the phase current of the winding. In the subdivision drive circuit, the phase current of the motor no longer works in the switch state, but changes continuously from 0 to the rated value. Suppose the two-phase currents are i _A , i _B , and the resultant current vector is i _M , as shown in Figure 2(b). Satisfy the following relationship:

i _a = i _M sinα (1)

i _b =i _M cosα (2)

α is the direction angle of the current vector. Every time the direction of the current vector changes by 90°, the rotor of the motor turns 1 step angle (1/4 tooth pitch). If the direction angle of the current vector changes by 90°/n each time, the rotor rotates 1/n of a step angle correspondingly, realizing n times subdivision of the step angle of the stepping motor. It can be seen from the above formula that when the currents of the A and B two-phase windings change regularly with sine waves with equal amplitude and a phase difference of 90°, the torque remains constant and rotates evenly. The motor torque variation after subdivision is shown in Fig. 2(c).

SPWM wave is the abbreviation of sinusoidal pulse width modulation wave. The generation of SPWM is realized by FPGA. The principle and generation method of FPGA-based stepper motor driving SPWM wave are explained as follows.

SPWM wave is a kind of pulse width modulation waveform, and its characteristic is that the change law of duty cycle is a sinusoidal function. After the SPWM passes through the H-bridge power drive circuit, the size of the duty cycle is converted into the size of the average current through the motor winding. Two-way SPWM waves modulated with a sine law with a phase difference of 90° are respectively generated, and connected to the A and B phases of the two-phase stepping motor after passing through the bipolar H-bridge power drive circuit 4 to realize subdivision driving.

In the lidar design, the number of teeth of the stepper motor rotor used for the azimuth angle is 200, the tooth pitch is 1.8°, the step angle is 0.45°, the pitch angle stepper motor has 50 teeth, the tooth pitch is 7.2°, and the step angle is 1.8°. Carry out 512 subdivisions to a step angle of azimuth stepper motor, 1024 subdivisions to a step angle of pitch motor 6, the process that FPGA produces SPWM as shown in Figure 3, SPWM subdivision drive controller 3 of the present invention comprises: system clock, pitch axis step pulse generator, the first counter, the first look-up table module, the second look-up table module, azimuth axis step pulse generator, the second counter, the third look-up table module, the fourth look-up table module, carrier counter, translation correction module, the first comparator, the second comparator, the third comparator and the fourth comparator; the pitch axis step pulse generator is connected with the DSP closed-loop controller 2 and the system clock respectively, the first counter is connected with the DSP closed-loop controller 2, the system clock and the pitch axis step pulse generator respectively, the first table look-up module is connected with the first counter, the second table look-up module is connected with the first counter, the azimuth axis step pulse generator is connected with the DSP closed-loop controller 2 and the system clock respectively, and the second counter is connected with the DSP closed-loop controller 2, the system clock and the orientation respectively The axis step pulse generator is connected, the third look-up module is connected with the second counter, the fourth look-up module is connected with the second counter, the carrier counter is connected with the system clock, the translation correction module is respectively connected with the first look-up module, the second look-up module, the third look-up module and the fourth look-up module, the first comparator is connected with the carrier counter and the translation correction module, the second comparator is connected with the carrier counter and the translation correction module, and the third comparator is connected with the carrier counter and the translation correction module, respectively. The fourth comparator is respectively connected with the carrier counter and the translation correction module.

The system clock is used to generate the clock signal. The pitch axis step pulse generator is used to determine the first step pulse according to the frequency division coefficient of the pitch motor 6 and the clock signal; the frequency division coefficient of the pitch motor 6 determines the first step pulse frequency, that is, determines the pitch motor 6 speed.

The first counter is used to count according to the moving direction of the pitching motor 6 and the first stepping pulse to obtain a first count value; specifically, when the moving direction of the pitching motor 6 is positive, the first stepping pulse is counted up; when the moving direction of the pitching motor 6 is negative, the first stepping pulse is counted down.

The first table lookup module is used to determine the pitch axis SIN value by looking up the pitch axis SIN table according to the first count value; the second lookup table module is used to determine the pitch axis COS value by looking up the pitch axis COS table according to the first count value; the third table lookup module is used to determine the azimuth axis SIN value by looking up the azimuth axis SIN table according to the second count value; the fourth table lookup module is used to determine the azimuth axis COS value by looking up the azimuth axis COS table according to the second count value. The present invention obtains the corresponding SIN value (i.e. sine value) and COS value (i.e. cosine value) according to the count value table lookup, and the sine type function only needs to establish a 1/4 cycle lookup table to calculate the value of the entire cycle. For the azimuth axis, the size of the lookup table is 512×12bit; for the pitch axis, the size of the lookup table is 1024×12bit. The table outputs are all 12bit wide. The design carrier cycle is 0~4095 (12bit), and the amplitude of SIN and COS functions is designed to be 3/4 (1536) of 1/2 carrier cycle.

The azimuth axis stepping pulse generator is used to determine the second stepping pulse according to the frequency division coefficient of the azimuth motor 7 and the clock signal;

The second counter is used to count according to the moving direction of the azimuth motor 7 and the second stepping pulse to obtain a second counting value; specifically, when the moving direction of the azimuth motor 7 is positive, the second stepping pulse is counted up; when the moving direction of the azimuth motor 7 is negative, the second stepping pulse is counted down.

The carrier counter is used to count the clock signal to obtain the carrier value; the transplanting modification module is used to transfer the pitch shaft SIN value, the pitch shaft COS value, the axis shaft value, and the axis shaft COS value. For comparison, obtain a pitch motor A -phase SPWM wave; the second comparator is used to compare the carrier value with the corrected pitch shaft COS value to obtain the pitch motor B phase SPWM wave; The axis shaft SIN values are compared to obtain a orientation motor A -phase SPWM wave; the fourth comparator is used to compare the load -wave value with the corrected axis shaft COS value to obtain a orientation motor B phase SPWM wave;

The SPWM subdivision drive controller 3 in the present invention is designed with an aerospace-grade high-reliability antifuse FPGA product, which has strong immunity to space radiation and single event effects, and meets the needs of space rendezvous and docking. The FPGA mainly realizes the subdivision drive control of the stepping motor. According to the direction parameter input by the DSP and the frequency division factor of the stepping motor, corresponding SPWM waves of phase A of the pitching motor, SPWM waves of the B phase of the pitching motor, SPWM waves of the A phase of the azimuth motor and SPWM waves of the B phase of the azimuth motor, that is, the first SPWM wave and the second SPWM wave.

The SPWM wave is generated by the above method to drive the stepper motor. The relationship between the motor speed V (unit °/s) and the frequency division coefficient C input by the DSP is as follows:

In the formula, V is the motor speed, C is the frequency division coefficient, D is the motor step angle (1/4 pitch, unit °), N is the subdivision number, and F is the system clock frequency (unit Hz).

As an embodiment, the SPWM subdivision drive controller 3 of the present invention further includes: a translation correction module, respectively connected to the first table look-up module, the second table look-up module, the third table look-up module, the fourth table look-up module, the first comparator, the second comparator, the third comparator, and the fourth comparator, for performing translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value, and the azimuth axis COS value. When the table lookup value is 0, the corresponding duty cycle is 50%. That is 1/2 carrier period (2048). The variation range of the corrected SIN and COS values is 2048±1536. Based on the system clock, the carrier counts from 0 to 4095. After comparing with the corrected SIN and COS values, it outputs a square wave whose high-level proportion in the carrier cycle changes according to the sine/cosine law, that is, a two-phase SPWM wave drive signal with a phase difference of 90°.

As an embodiment, the four bipolar H-bridge power drive circuits 4 of the present invention are respectively: an azimuth motor A-phase winding drive circuit, an azimuth motor B-phase winding drive circuit, a pitch motor A-phase winding drive circuit and a pitch motor B-phase winding drive circuit. The circuit structure diagram of the B-phase winding drive circuit of the azimuth motor, the A-phase winding drive circuit of the pitch motor, and the B-phase winding drive circuit of the pitch motor is the same as the circuit structure diagram of the A-phase winding drive circuit of the azimuth motor, and no drawings are given here.

以方位电机A相绕组为例，如图4所示，所述方位电机A相绕组驱动电路包括第一开关管Q ₁ 、第二开关管Q ₂ 、第三开关管Q ₃ 、第四开关管Q ₄和方位电机A相绕组L ₁ ；所述第一开关管Q ₁的第一端、所述第三开关管Q ₃的第一端分别与驱动电源正极连接，所述第一开关管Q ₁的第三端分别与第二开关Q ₂管的第一端和所述方位电机A相绕组L ₁的一端连接，所述方位电机A相绕组L ₁的另一端分别与所述第三开关管Q ₃的第三端和所述第四开关管Q ₄的第一端连接，所述第四开关管Q ₄的第三端与所述第二开关管Q ₂的第三端分别与驱动电源负极连接，所述第一开关管Q ₁的第二端和所述第四开关管Q ₄的第二端分别与所述第一比较器输出的方位电机A相SPWM波连接，所述第二开关管Q ₂的第二端和所述第三开关管Q ₃的第二端分别与所述第一比较器输出的方位电机A相SPWM波取反的信号连接。 When the first switching tube Q ₁ , the second switching tube Q ₂ , the third switching tube Q ₃ and the fourth switching tube Q ₄ in the present invention are all MOS tubes, the first terminal is the drain, the second terminal is the gate, and the third terminal is the source.

The first switching tube Q ₁ and the fourth switching tube Q ₄ form a group, and the second switching tube Q ₂ and the third switching tube Q ₃ form a group. The same group of MOS transistors input the same waveform and are turned on or off at the same time. The input waveforms of different groups of MOS transistors are electrically turned on, and the level is inverted. When one group of MOS transistors is turned on, the other group of MOS transistors is turned off.

In a PWM cycle, when the input waveform U ₁ is at a high level, the first switching tube Q _{1 and} the fourth switching tube Q ₄ are turned on _, and at this time U ₂ is at a low level, the second _switching tube Q _{2 and} the third switching tube Q ₃ are turned off, and the motor winding bears the forward voltage from A+ to A-; Through, the motor winding bears the _reverse voltage from A- to A+.

In a PWM cycle, the relationship between the average voltage Ua on the motor winding and the duty cycle is as follows:

Among them, U _s is the power supply voltage of the driving circuit, T is the PWM period, t ₁ is the high level time, and r is the duty cycle. It can be seen that when the duty cycle is 50%, the average voltage across the motor windings is 0.

According to the aforementioned FPGA-based SPWM wave generation process, the changing law of the duty cycle is as follows:

Putting it into the above formula, the change law of the average voltage of the motor winding is obtained as:

U _a = p·U _S ·sinα (6)

In the formula, p is the ratio of the amplitude of the sinusoidal function to the 1/2 period. In the actual design, p is selected as 0.75. It can be seen that the average voltage and current on the motor winding change according to the sinusoidal law.

The B-phase winding drive circuit of the azimuth motor in the present invention includes a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, and a B-phase winding of the azimuth motor; the first end of the fifth switch tube and the first end of the seventh switch tube are respectively connected to the positive pole of the driving power supply; the third end of the fifth switch tube is respectively connected to the first end of the sixth switch tube and one end of the B-phase winding of the azimuth motor; The third end of the tube and the third end of the sixth switching tube are respectively connected to the negative pole of the drive power supply, the second end of the fifth switching tube and the second end of the eighth switching tube are respectively connected to the B-phase SPWM wave of the azimuth motor output by the second comparator, and the second end of the sixth switching tube and the second end of the seventh switching tube are respectively connected to the inverted signal of the B-phase SPWM wave of the azimuth motor output by the second comparator.

The pitch motor A-phase winding drive circuit of the present invention includes a ninth switch tube, a tenth switch tube, an eleventh switch tube, a twelfth switch tube, and a pitch motor A-phase winding; the first end of the ninth switch tube and the first end of the eleventh switch tube are respectively connected to the positive pole of the driving power supply; the third end of the ninth switch tube is connected to the first end of the twentieth switch tube and one end of the A-phase winding of the pitch motor; The third end of the twelfth switching tube and the third end of the tenth switching tube are respectively connected to the negative pole of the drive power supply, the second end of the ninth switching tube and the second end of the twelfth switching tube are respectively connected to the phase A SPWM wave of the pitch motor output by the third comparator, and the second end of the tenth switching tube and the second end of the eleventh switching tube are respectively connected to the inverted signal of the phase A SPWM wave of the pitch motor output by the third comparator.

The pitch motor B-phase winding drive circuit of the present invention includes a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube, a sixteenth switch tube, and a pitch motor B-phase winding; the first end of the thirteenth switch tube and the first end of the fifteenth switch tube are respectively connected to the positive pole of the driving power supply; the third end of the thirteenth switch tube is respectively connected to the first end of the fourteenth switch tube and one end of the B-phase winding of the pitch motor; The first end of the switch tube is connected, the third end of the sixteenth switch tube and the third end of the fourteenth switch tube are respectively connected to the negative pole of the driving power supply, the second end of the thirteenth switch tube and the second end of the sixteenth switch tube are respectively connected to the B-phase SPWM wave of the pitch motor output by the fourth comparator, and the second end of the fourteenth switch tube and the second end of the fifteenth switch tube are respectively connected to the inverted signal of the B-phase SPWM wave of the pitch motor output by the fourth comparator.

As an embodiment, the system of the present invention further includes: a photoelectric isolation circuit, arranged between the SPWM subdivision drive controller 3 and the four bipolar H-bridge power drive circuits 4, for optocoupler isolation of the first SPWM wave and the second SPWM wave.

As an embodiment, the system of the present invention further includes: 8 power drive chips, arranged between the photoelectric isolation circuit and the four bipolar H-bridge power drive circuits 4, for respectively driving the A-phase winding drive circuit of the azimuth motor, the B-phase winding drive circuit of the azimuth motor, the A-phase winding drive circuit of the pitch motor, and the B-phase winding drive circuit of the pitch motor.

In the lidar design, after the SPWM wave generated by the SPWM subdivision drive controller 3 passes through the photoelectric isolation circuit for optocoupler isolation, the power drive chip IR2110 is input to drive the bipolar H-bridge power drive circuit 4 . IR2110 has a high-speed switching frequency, which meets the application requirements ranging from dozens of Hz to hundreds of kHz. It also has two input and output channels, and a dead zone protection function with slow turn-on and fast turn-off to prevent the bridge arm from passing through. One IR2110 controls the MOS tubes of the upper and lower bridge arms of the same side of the H-bridge, so each phase winding drive circuit needs two IR2110. In addition, the power MOS tube of the H bridge is selected from IRHNJ67230, which has the characteristics of enhanced space radiation and single event effect, and the continuous working current reaches more than 10A.

The present invention also provides a space rendezvous and docking lidar scanning and tracking control method, the method comprising:

Step S10: Obtain the angle value of the azimuth axis and the angle value of the pitch axis by using the angle sensor.

Step S20: Determine the two-dimensional miss amount according to the energy of the echo in each quadrant.

Step S30: Determine the motion direction and frequency division coefficient of the two stepper motors according to the angle value of the azimuth axis, the angle value of the pitch axis, and the two-dimensional miss amount; the motion directions of the two stepper motors include: the motion direction of the pitch motor and the motion direction of the azimuth motor; the frequency division coefficients of the two stepper motors include the frequency division coefficient of the pitch motor and the frequency division coefficient of the azimuth motor.

Step S40: Determine the first SPWM wave and the second SPWM wave according to the moving directions of the two stepping motors and the frequency division coefficient.

Step S50: after amplifying the first SPWM wave and the second SPWM wave, respectively control two stepping motors, so that the two stepping motors respectively drive the azimuth axis and the pitch axis to rotate, and then drive the four-quadrant detector 5 to scan and track; the two stepping motors are respectively an azimuth motor and a pitch motor.

As an implementation, the present invention determines the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepping motors, specifically including:

Step S401: Obtain a clock signal.

Step S402: Determine a first step pulse according to the frequency division coefficient of the pitch motor and the clock signal.

Step S403: Counting is performed according to the moving direction of the pitch motor and the first stepping pulse to obtain a first count value.

Step S404: Determine the azimuth axis SIN value by looking up the azimuth axis SIN table according to the first count value.

Step S405: Determine the pitch axis COS value by looking up the azimuth axis COS table according to the first count value.

Step S406: Carrier counting is performed on the clock signal to obtain a carrier value.

Step S407: Determine a second step pulse according to the frequency division factor of the azimuth motor and the clock signal.

Step S408: Counting is performed according to the moving direction of the azimuth motor and the second stepping pulse to obtain a second count value.

Step S409: Determine the azimuth axis SIN value by looking up the azimuth axis SIN table according to the second count value.

Step S410: Determine the COS value of the azimuth axis by searching the COS table of the azimuth axis according to the second count value.

Step S411: performing translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value and the azimuth axis COS value.

Step S412: Comparing the carrier value with the corrected SIN value of the pitch axis to obtain the A-phase SPWM wave of the pitch motor.

Step S413: Compare the carrier value with the corrected COS value of the pitch axis to obtain the B-phase SPWM wave of the pitch motor; the first SPWM wave includes the A-phase SPWM wave of the pitch motor and the B-phase SPWM wave of the pitch motor.

Step S414: Comparing the carrier value with the corrected SIN value of the azimuth axis to obtain the A-phase SPWM wave of the azimuth motor.

Step S415: Compare the carrier value with the corrected COS value of the azimuth axis to obtain the B-phase SPWM wave of the azimuth motor; the second SPWM wave includes the A-phase SPWM wave of the azimuth motor and the B-phase SPWM wave of the azimuth motor.

Advantages of the present invention include:

1. The system has a compact structure and a high degree of integration, mainly including the following two aspects.

(1) Using a single-chip FPGA with the peripheral H-bridge drive circuit, the subdivision drive control of the two-axis stepping motor of the laser radar can be realized. FPGA is one of the core chips in the lidar electronic control system, which realizes functions such as DSP peripheral interface expansion and logic control. The FPGA is used to generate the SPWM wave required for the two-axis stepper motor movement according to the input frequency division coefficient and direction information of the DSP. There is no need to add a dedicated motor driver chip or module, which improves the integration and reliability of the system and also helps to reduce the weight of the system.

(2) Establish a closed-loop control system based on the high-precision subdivision drive of the stepper motor, use the single-chip DSP as the controller, and use the angle sensor and the four-quadrant detector miss-target as the double feedback, and realize the high-speed scanning control and stable tracking control of the two-axis stepper motor at the same time. DSP is the control core of lidar. In addition to realizing motor control, it also realizes functions such as radar system control and interface communication. Without adding additional control chips and sensors, the required control function and performance index are realized, and the circuit and structure are simplified.

2. The output torque of the motor is stable, the speed can be adjusted in a large range, the subdivision precision is high and the subdivision precision is controllable. In the process of high-speed scanning and stable tracking, the acceleration changes greatly, and the output torque of the stepping motor remains basically stable, so that the output power of the power supply remains basically constant, reducing the impact on the power supply. Using the stepper motor subdivision drive control method based on SPWM wave, the number of subdivision steps can be designed according to the needs to achieve the required subdivision accuracy, and a compromise can be made between the highest speed and the minimum step angle. In the actual design, the step angle of the laser radar pitch motor is about 0.0018° after subdivision, the step angle of the azimuth motor is about 0.0009° after subdivision, and the maximum speed during the scanning process of the pitch axis reaches more than 1000°/s.

3. Meet the application requirements of space rendezvous and docking. The DSP, FPGA, and bipolar H-bridge power drive circuit used in the stepping motor subdivision drive closed-loop control system are all aerospace-grade high-reliability products, and the reliability and redundancy design have been strengthened in the DSP software and FPGA logic design, which has strong space environment adaptability. The system structure and circuit are compact, highly integrated, and the volume and weight meet the constraints on aerospace loads.

Each embodiment in the description of the present invention is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

In the present invention, specific examples are used to illustrate the principle of the present invention and the implementation mode. The description of the above examples is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the thought of the present invention, there will be changes in the specific implementation mode and the scope of application. In summary, the contents of the description of the present invention should not be construed as limiting the present invention.

Claims (5)

1. A space rendezvous and docking laser radar scanning and tracking control system is characterized in that the system includes: An angle sensor is used to detect the angle value of the azimuth axis and the angle value of the pitch axis; The four-quadrant detector is used to determine the two-dimensional miss amount according to the energy of the echo in each quadrant; The DSP closed-loop controller is connected with the angle sensor and the four-quadrant detector respectively, and is used to determine the direction of motion and the frequency division coefficient of two stepper motors according to the angle value of the azimuth axis, the angle value of the pitch axis and the two-dimensional miss amount; the direction of motion of the two stepper motors includes: the direction of motion of the pitch motor and the direction of motion of the azimuth motor; the frequency division coefficient of the two stepper motors includes the frequency division coefficient of the pitch motor and the frequency division coefficient of the azimuth motor; A SPWM subdivision drive controller, connected with the DSP closed-loop controller, is used to determine the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepping motors; 4 bipolar H-bridge power drive circuits are respectively connected with the SPWM subdivision drive controller and two stepping motors, and are used to amplify the first SPWM wave and the second SPWM wave and control the two stepping motors respectively, so that the two stepping motors drive the rotation of the azimuth axis and the pitch axis respectively, and then drive the four-quadrant detector to scan and track; the two stepper motors are respectively an azimuth motor and a pitch motor; The SPWM subdivision drive controller includes: The system clock is used to generate a clock signal; A pitch axis stepping pulse generator, connected to the DSP closed-loop controller and the system clock respectively, for determining a first stepping pulse according to the frequency division factor of the pitching motor and the clock signal; The first counter is respectively connected with the DSP closed-loop controller, the system clock and the pitch axis step pulse generator, and is used to count according to the motion direction of the pitch motor and the first step pulse to obtain a first count value; The first table look-up module is connected to the first counter, and is used to determine the pitch axis SIN value by looking up the pitch axis SIN table according to the first count value; The second table look-up module is connected to the first counter, and is used to determine the pitch axis COS value by looking up the pitch axis COS table according to the first count value; An azimuth axis stepping pulse generator is connected with the DSP closed-loop controller and the system clock respectively, and is used to determine the second stepping pulse according to the frequency division factor of the azimuth motor and the clock signal; The second counter is connected with the DSP closed-loop controller, the system clock and the azimuth axis step pulse generator respectively, and is used to count according to the movement direction of the azimuth motor and the second step pulse to obtain a second count value; The third table look-up module is connected to the second counter, and is used to determine the azimuth axis SIN value by searching the azimuth axis SIN table according to the second count value; The fourth table look-up module is connected with the second counter, and is used to determine the azimuth axis COS value by searching the azimuth axis COS table according to the second count value; A carrier counter, connected to the system clock, is used to count the carrier of the clock signal to obtain the carrier value; The translation correction module is respectively connected with the first table look-up module, the second table look-up module, the third table look-up module and the fourth table look-up module, and is used to perform translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value and the azimuth axis COS value; The first comparator is connected to the carrier counter and the translation correction module respectively, and is used to compare the carrier value with the corrected pitch axis SIN value to obtain a phase A SPWM wave of the pitch motor; The second comparator is respectively connected to the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected COS value of the pitch axis to obtain a B-phase SPWM wave of the pitch motor; the first SPWM wave includes a pitch motor A-phase SPWM wave and a pitch motor B-phase SPWM wave; The third comparator is respectively connected with the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected azimuth axis SIN value to obtain the A-phase SPWM wave of the azimuth motor; The fourth comparator is respectively connected with the carrier counter and the translation correction module, and is used to compare the carrier value with the corrected azimuth axis COS value to obtain the B-phase SPWM wave of the azimuth motor; the second SPWM wave includes the A-phase SPWM wave of the azimuth motor and the B-phase SPWM wave of the azimuth motor; The four bipolar H-bridge power drive circuits are: A-phase winding drive circuit for azimuth motor, B-phase winding drive circuit for azimuth motor, A-phase winding drive circuit for pitch motor, and B-phase winding drive circuit for pitch motor; The A-phase winding drive circuit of the azimuth motor includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an A-phase winding of the azimuth motor; the first end of the first switch tube and the first end of the third switch tube are respectively connected to the positive pole of the driving power supply; the third end of the first switch tube is respectively connected to the first end of the second switch tube and one end of the A-phase winding of the azimuth motor; The third end of the second switching tube is connected to the negative pole of the driving power supply respectively, the second end of the first switching tube and the second end of the fourth switching tube are respectively connected to the A-phase SPWM wave of the azimuth motor output by the first comparator, and the second end of the second switching tube and the second end of the third switching tube are respectively connected to the inverted signal of the A-phase SPWM wave of the azimuth motor output by the first comparator; The B-phase winding drive circuit of the azimuth motor includes a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, and a B-phase winding of the azimuth motor; the first end of the fifth switch tube and the first end of the seventh switch tube are respectively connected to the positive pole of the driving power supply; the third end of the fifth switch tube is respectively connected to the first end of the sixth switch tube and one end of the B-phase winding of the azimuth motor; The third end of the third switch tube and the third end of the sixth switch tube are respectively connected to the negative pole of the driving power supply, the second end of the fifth switch tube and the second end of the eighth switch tube are respectively connected to the B-phase SPWM wave of the azimuth motor output by the second comparator, and the second end of the sixth switch tube and the second end of the seventh switch tube are respectively connected to the reversed signal of the B-phase SPWM wave of the azimuth motor output by the second comparator; The pitch motor A-phase winding driving circuit includes a ninth switch tube, a tenth switch tube, an eleventh switch tube, a twelfth switch tube, and a pitch motor A-phase winding; the first end of the ninth switch tube and the first end of the eleventh switch tube are respectively connected to The third end of the ninth switching tube is connected to the positive pole of the driving power supply, the third end of the ninth switching tube is connected to the first end of the twentieth switching tube and one end of the A-phase winding of the pitch motor, the other end of the A-phase winding of the pitching motor is respectively connected to the third end of the eleventh switching tube and the first end of the twelfth switching tube, the third end of the twelfth switching tube and the third end of the tenth switching tube are respectively connected to the negative pole of the driving power supply, and the second end of the ninth switching tube and the second end of the twelfth switching tube are respectively connected to the phase A of the pitching motor output by the third comparator. SPWM wave connection, the second end of the tenth switching tube and the second end of the eleventh switching tube are respectively connected to the inverted signal of the pitch motor A phase SPWM wave output by the third comparator; The pitch motor B-phase winding driving circuit includes a thirteenth switch tube, a fourteenth switch tube, a fifteenth switch tube, a sixteenth switch tube, and a pitch motor B-phase winding; the first end of the thirteenth switch tube and the first end of the fifteenth switch tube are respectively connected to the positive pole of the driving power supply; the third end of the thirteenth switch tube is connected to the first end of the fourteenth switch tube and one end of the B-phase winding of the pitch motor; The first end of the switch tube is connected, the third end of the sixteenth switch tube and the third end of the fourteenth switch tube are respectively connected to the negative pole of the driving power supply, the second end of the thirteenth switch tube and the second end of the sixteenth switch tube are respectively connected to the B-phase SPWM wave of the pitch motor output by the fourth comparator, and the second end of the fourteenth switch tube and the second end of the fifteenth switch tube are respectively connected to the inverted signal of the B-phase SPWM wave of the pitch motor output by the fourth comparator; When the first switching tube, the second switching tube, the third switching tube, the fourth switching tube, the fifth switching tube, the sixth switching tube, the seventh switching tube, the eighth switching tube, the ninth switching tube, the tenth switching tube, the eleventh switching tube, the twelfth switching tube, the thirteenth switching tube, the fourteenth switching tube, the fifteenth switching tube and the sixteenth switching tube are all MOS tubes, the first terminal is a drain, the second terminal is a gate, and the third terminal is a source. 2. The space rendezvous and docking lidar scanning and tracking control system according to claim 1, wherein the system further comprises: The photoelectric isolation circuit is arranged between the SPWM subdivision drive controller and the four bipolar H-bridge power drive circuits, and is used for optocoupler isolation of the first SPWM wave and the second SPWM wave. 3. The space rendezvous and docking laser radar scanning and tracking control system according to claim 2, is characterized in that, said system also comprises: Eight power drive chips are arranged between the photoelectric isolation circuit and the four bipolar H-bridge power drive circuits, and are used to respectively drive the A-phase winding drive circuit of the azimuth motor, the B-phase winding drive circuit of the azimuth motor, the A-phase winding drive circuit of the pitch motor, and the B-phase winding drive circuit of the pitch motor. 4. The space rendezvous and docking lidar scanning and tracking control system according to claim 3, characterized in that the model of the power driver chip is IR2110. 5. A space rendezvous and docking laser radar scanning and tracking control method, characterized in that the method comprises: Use the angle sensor to obtain the angle value of the azimuth axis and the angle value of the pitch axis; Determine the two-dimensional off-target amount according to the energy of the echo in each quadrant; According to the angle value of the azimuth axis, the angle value of the pitch axis and the two-dimensional miss amount, the direction of motion and the frequency division coefficient of the two stepper motors are determined; the direction of motion of the two stepper motors includes: the direction of motion of the pitch motor and the direction of motion of the azimuth motor; the frequency division coefficients of the two stepper motors include the frequency division coefficient of the pitch motor and the frequency division coefficient of the azimuth motor; Determine the first SPWM wave and the second SPWM wave according to the direction of motion and the frequency division coefficient of the two stepper motors; After amplifying the first SPWM wave and the second SPWM wave, control two stepper motors respectively, so that the two stepper motors drive the azimuth axis and the pitch axis to rotate respectively, and then drive the four-quadrant detector to scan and track; the two stepper motors are respectively an azimuth motor and a pitch motor; the first SPWM wave and the second SPWM wave are determined according to the direction of motion and the frequency division coefficient of the two stepper motors, specifically comprising: get clock signal; determining a first step pulse according to the frequency division factor of the pitch motor and the clock signal; Counting according to the motion direction of the pitch motor and the first step pulse to obtain a first count value; Determine the pitch axis SIN value by looking up the pitch axis SIN table according to the first count value; Determine the pitch axis COS value by looking up the pitch axis COS table according to the first count value; Perform carrier counting on the clock signal to obtain the carrier value; determining a second stepping pulse according to the frequency division factor of the azimuth motor and the clock signal; Counting according to the moving direction of the azimuth motor and the second stepping pulses to obtain a second count value; Determine the azimuth axis SIN value by searching the azimuth axis SIN table according to the second count value; determining the azimuth axis COS value by searching the azimuth axis COS table according to the second count value; Perform translation correction on the pitch axis SIN value, the pitch axis COS value, the azimuth axis SIN value and the azimuth axis COS value; Comparing the carrier value with the corrected pitch axis SIN value to obtain a phase A SPWM wave of the pitch motor; Comparing the carrier value with the corrected COS value of the pitch axis to obtain the B-phase SPWM wave of the pitch motor; the first SPWM wave includes the A-phase SPWM wave of the pitch motor and the B-phase SPWM wave of the pitch motor; The carrier value is compared with the corrected azimuth axis SIN value to obtain the A-phase SPWM wave of the azimuth motor; The carrier value is compared with the corrected COS value of the azimuth axis to obtain the B-phase SPWM wave of the azimuth motor; the second SPWM wave includes the A-phase SPWM wave of the azimuth motor and the B-phase SPWM wave of the azimuth motor.