Servo control method and system for tracking rotary table

Abstract

The invention discloses a servo control method and system for a tracking turntable, and belongs to the technical field of tracking measurement. The method comprises the following steps: receiving tracking data, and setting a corresponding working mode flag bit after processing the tracking data; calling the tracking data by using the interrupt function, and generating a control quantity corresponding to the tracking data according to the working mode flag bit; a pulse width modulation signal corresponding to the control amount is generated. According to the invention, stable tracking measurement of an infrared and visible light detector on a target can be realized, and the servo control system for the tracking turntable integrates driving and control of a servo motor, so that the production, research and development cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of tracking measurement technology, and in particular to a servo control method and system for a tracking turntable. Background Art

[0002] The optoelectronic tracking turntable is a complex system that integrates optics, mechanics, electricity and computer applications. It is an indispensable key hardware system for target range measurement equipment, optoelectronic tracking measurement equipment, astronomical observation equipment, aerospace field, laser communication equipment, optoelectronic capture tracking and aiming equipment, etc.

[0003] In the related art, the turntable is prone to eccentricity. In order to solve this problem, the prior art uses a reducer to connect the motor and the frame to increase the output torque and improve the turntable response rate, but this will affect the control accuracy and speed stability of the turntable and make it impossible to stably track and measure the target. Summary of the invention

[0004] The present invention provides a servo control method and system for a tracking turntable, which can solve the problem of the related art that the target cannot be stably tracked and measured. The technical solution is as follows:

[0005] In one aspect, a servo control method for a tracking turntable is provided, the method comprising:

[0006] receiving tracking data, and setting a corresponding working mode flag after processing the tracking data;

[0007] Using an interrupt function to call the tracking data, and generating a control amount corresponding to the tracking data according to the working mode flag;

[0008] A pulse width modulation signal corresponding to the control amount is generated; wherein the pulse width modulation signal is used to control the DC brushless motor and / or the servo motor to drive the rotation of the tracking turntable.

[0009] Optionally,

[0010] Before receiving the tracking data, the following steps are also included: hardware initialization, system initialization and servo operating environment initialization for the servo used for the tracking turntable;

[0011] The tracking data includes encoder data, hand lever information data, photoelectric tracking miss amount data, and display and control system data; receiving tracking data includes: receiving the encoder data, the hand lever information data, the photoelectric tracking miss amount data, and the display and control system data in order from high to low priority by using an interrupt mode;

[0012] The method also includes: obtaining speed feedback and position feedback of the tracking turntable, an azimuth voltage signal of a brushless DC motor, and a pitch voltage signal of a servo motor; and adjusting the control amount according to the speed feedback, the position feedback, the azimuth voltage signal, and the pitch voltage signal.

[0013] On the other hand, a servo control system for a tracking turntable is provided, the system comprising a servo control unit and a servo drive unit; the servo control unit comprises a digital signal processor and a complex programmable logic device; the servo drive unit comprises an azimuth drive unit and a pitch drive unit; wherein,

[0014] The complex programmable logic device receives the tracking data, and sets a corresponding working mode flag after processing the tracking data; and then sends the tracking data with the working mode flag to the digital signal processor;

[0015] The digital signal processor uses an interrupt function to call the tracking data, generates a control amount corresponding to the tracking data according to the working mode flag, and writes the control amount into the complex programmable logic device;

[0016] The complex programmable logic device generates a pulse width modulation signal corresponding to the control amount, and sends the pulse width modulation signal to the azimuth driving unit and / or the pitch driving unit;

[0017] The azimuth drive unit generates a DC brushless motor drive current according to the pulse width modulation signal, and / or the pitch drive unit generates a servo motor drive current according to the pulse width modulation signal; wherein the DC brushless motor drive current is used to control the DC brushless motor to drive the azimuth rotation of the tracking turntable, and the servo motor drive current is used to control the servo motor to drive the pitch rotation of the tracking turntable.

[0018] Optionally, the digital signal processor is provided with an external memory interface; the servo control unit further comprises an azimuth pulse width modulation circuit, an elevation pulse width modulation circuit, an azimuth level conversion circuit and an elevation level conversion circuit; wherein,

[0019] The complex programmable logic device sends the tracking data with the operating mode flag to the digital signal processor through the external memory interface;

[0020] The digital signal processor uses an interrupt function to call the tracking data, generates a control amount corresponding to the tracking data according to the working mode flag, and writes the control amount into the complex programmable logic device through the external memory interface;

[0021] The complex programmable logic device generates an azimuth pulse width modulation signal and an elevation pulse width modulation signal corresponding to the control amount through the azimuth pulse width modulation circuit and the elevation pulse width modulation circuit, and sends the azimuth pulse width modulation signal to the azimuth drive unit through the azimuth level conversion circuit, and sends the elevation pulse width modulation signal to the elevation drive unit through the elevation level conversion circuit.

[0022] Optionally, the digital signal processor is further provided with an analog-to-digital converter; the azimuth drive unit includes a DC brushless motor driver, an azimuth photoelectric isolation and an azimuth Hall current sensor; the pitch drive unit includes a servo motor driver, a pitch photoelectric isolation and a pitch Hall current sensor; wherein,

[0023] The azimuth photoelectric isolation receives the azimuth pulse width modulation signal sent by the azimuth level conversion circuit, the DC brushless motor driver controls the DC brushless motor according to the azimuth pulse width modulation signal, and the azimuth Hall current sensor adjusts the current voltage signal of the DC brushless motor driver to an azimuth voltage signal of 0 to 3V and then connects to the analog-to-digital converter;

[0024] and / or,

[0025] The pitch photoelectric isolation receives the pitch pulse width modulation signal sent by the pitch level conversion circuit, the servo motor driver controls the servo motor according to the pitch pulse width modulation signal, and the pitch Hall current sensor conditions the current voltage signal of the servo motor driver to a pitch voltage signal of 0 to 3V and then connects to the analog-to-digital converter.

[0026] Optionally, the complex programmable logic device obtains speed feedback and position feedback of the tracking turntable and sends them to the digital signal processor through the external memory interface;

[0027] The digital signal processor adjusts the control amount according to the speed feedback, the position feedback, the azimuth voltage signal and the pitch voltage signal.

[0028] On the other hand, a tracking turntable is provided, the tracking turntable is controlled by the above-mentioned servo control method for a tracking turntable or by the above-mentioned servo control system for a tracking turntable, the tracking turntable comprises: an azimuth seat, a merge ring, a DC brushless motor, a code disk, a supporting U-shaped frame, a pitch package, a pitch axis system, a servo motor, an infrared thermal imager and a visible light camera, wherein:

[0029] The azimuth seat is sequentially mounted with the merge ring, the brushless DC motor, the encoder, the supporting U-shaped frame and the pitch package;

[0030] The pitch axis system and the servo motor are installed in the support U-shaped frame, and the pitch package is connected; wherein the end of the servo motor is provided with a photoelectric encoder;

[0031] The infrared thermal imager and the visible light camera are installed in the pitch package.

[0032] On the other hand, a computer device is provided, which includes a memory and a processor, wherein the memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the above-mentioned servo control method for a tracking turntable.

[0033] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored in the storage medium, and when the computer program is executed by a processor, the steps of the servo control method for a tracking turntable are implemented.

[0034] On the other hand, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the steps of the servo control method for a tracking turntable described above are implemented.

[0035] The technical solution provided by the present invention can at least bring the following beneficial effects:

[0036] Able to realize stable tracking and measurement of targets by infrared and visible light detectors;

[0037] The servo control system for the tracking turntable integrates servo motor drive and control, reducing production and R&D costs;

[0038] One driver chip is used to realize servo control of two types of motors, realizing servo control of two degrees of freedom: azimuth and pitch. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 is a flow chart of a servo control method for a tracking turntable provided by one embodiment of the present invention;

[0041] Figure 2 It is a structural diagram of a servo control system for a tracking turntable provided by one embodiment of the present invention;

[0042] Figure 3This is a structural diagram of a tracking turntable provided by an embodiment of the present invention;

[0043] Figure 4 This is a main program block diagram of a servo control system for a tracking turntable that can be used as a reference in the present invention;

[0044] Figure 5 This is a three-loop control diagram of a servo control system for a tracking turntable that can be used as a reference in the present invention;

[0045] Figure 6 It is a hardware architecture diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] As mentioned above, a servo control method and system for a tracking turntable proposed in an embodiment of the present invention integrates motor drive and control, reduces production and research and development costs, and uses a driver chip to realize servo control of two types of motors, thereby realizing servo control of two degrees of freedom, azimuth and pitch. For the convenience of testing, the tracking turntable can also be remotely controlled to adjust the posture of the two degrees of freedom, azimuth and pitch. In the working state, the tracking turntable realizes 360° continuous operation in the horizontal direction and +90° to -90° operation in the pitch direction.

[0048] The servo system hardware of the embodiment of the present invention is integrated inside the turntable. The servo control driver is the core component for realizing the movement of the turntable, and can realize servo control of the servo motor and the DC brushless motor. A DC brushless motor is used in the azimuth direction. This type of motor does not use a mechanical brush device. It has the characteristics of good speed regulation performance of a DC motor, and has the advantages of a simple structure, no commutation sparks, reliable operation and easy maintenance of an AC motor. In order to adapt to various detectors without balancing, the pitch direction adopts the method of gear plus servo motor, and uses a servo motor with a photoelectric encoder at the end. The load is driven after gear reduction. This type of motor has good high-speed performance and can withstand loads several times the rated torque. It is suitable for occasions with instantaneous load fluctuations and rapid startup.

[0049] At the same time, digital control is adopted. The servo control driver is composed of a digital signal processor, a complex programmable logic device and its peripheral circuits to complete the interface with peripheral devices and realize the servo control algorithm and system communication with the terminal.

[0050] The specific implementation of the above concept is described below.

[0051] Please refer to Figure 1 , an embodiment of the present invention provides a servo control method for a tracking turntable, the method comprising:

[0052] Step 101, receiving tracking data, and setting a corresponding working mode flag after processing the tracking data.

[0053] In the embodiment of the present invention, the tracking data includes encoder data, hand lever information data, photoelectric tracking miss amount data, and display and control system data. The encoder is a photoelectric encoder at the end of the servo motor on the tracking turntable. The encoder data includes the tracking turntable transfer information, etc. The hand lever information data is the data of manually controlling the tracking turntable. The photoelectric tracking miss amount data is the tracking target data. The display and control system data is the tracking situation of the tracking turntable displayed on the display. After completing the reception and processing of the above tracking data, the corresponding working mode flag is set. The working mode flag reflects the type or working mode corresponding to the tracking data, including search target, search mode, tracking target, tracking mode, adjusting display range, etc.

[0054] For step 101, the encoder data, the hand lever information data, the photoelectric tracking miss amount data, and the display and control system data can be received in an interrupt mode, and the encoder data, the hand lever information data, the photoelectric tracking miss amount data, and the display and control system data are received in the order of priority. Among them, the encoder data comes from the photoelectric encoder at the end of the servo motor, and the hand lever information data, the photoelectric tracking miss amount data, and the display and control system data are obtained from the outside through RS422 communication.

[0055] Step 102: Utilize the interrupt function to call the trace data, and generate the control amount corresponding to the trace data according to the working mode flag.

[0056] In the embodiment of the present invention, in order to save system resources and ensure the real-time performance of the system receiving data, an interrupt mode is used to receive data. The interrupt mode is one of the three working modes of serial communication. The interrupt function is run to interrupt the normal running program. After receiving one byte of data, an interrupt is applied again. Subsequent processing is completed in the interrupt service program. During the data reception, the CPU can perform other tasks, and the CPU utilization rate is high. The corresponding control amount is generated according to the type of tracking data, such as the control amount of tracking the target, the control amount of adjusting the display range, etc.

[0057] Step 103: Generate a pulse width modulation signal corresponding to the control amount.

[0058] In the embodiment of the present invention, the rotation of the tracking turntable is controlled by directly controlling the brushless DC motor and the servo motor of the tracking turntable. The pulse width modulation signal is used to control the brushless DC motor and / or the servo motor to drive the rotation of the tracking turntable.

[0059] As a preferred embodiment, the following steps are also included before step 101: hardware initialization, system initialization and servo operating environment initialization of the tracking turntable servo. In the hardware initialization stage, the tracking turntable servo performs a self-check after power-on, mainly reporting the angle after movement, and the self-check is normal if the end position of the movement is the initial horizontal zero degree. In the system initialization stage, the system is restored to the default initial state. In the servo operating environment initialization stage, the tracking turntable servo is restored to the default initial state.

[0060] As a preferred embodiment, after step 103, the following steps are also included: obtaining the speed feedback and position feedback of the tracking turntable, the azimuth voltage signal of the DC brushless motor, and the pitch voltage signal of the servo motor; adjusting the control amount according to the speed feedback, position feedback, azimuth voltage signal, and pitch voltage signal. To ensure the necessary means of high-precision and fast-response tracking of angular position and angular velocity, in order to improve the stability of the angular velocity of the servo system, a full closed-loop control method is adopted at the motor end and the load end, and at the same time, the speed feedback and position feedback at the load end and the voltage signal feedback at the motor end are used to adjust the control amount, thereby suppressing motion errors.

[0061] Please refer to Figure 2 The embodiment of the present invention provides a servo control system for a tracking turntable, which is composed of a servo control unit and a servo drive unit. The servo control unit includes a digital signal processor (DSP) and a complex programmable logic device (FPGA); the servo drive unit includes an azimuth drive unit and a pitch drive unit.

[0062] The complex programmable logic device receives the tracking data, and sets a corresponding working mode flag after processing the tracking data; and then sends the tracking data with the working mode flag to the digital signal processor;

[0063] The digital signal processor uses the interrupt function to call the tracking data, generates the control quantity corresponding to the tracking data according to the working mode flag, and writes the control quantity into the complex programmable logic device;

[0064] The complex programmable logic device generates a pulse width modulation signal corresponding to the control amount, and sends the pulse width modulation signal to the azimuth drive unit and / or the pitch drive unit;

[0065] The azimuth drive unit generates a DC brushless motor drive current according to a pulse width modulation signal, and / or the pitch drive unit generates a servo motor drive current according to a pulse width modulation signal; the DC brushless motor drive current is used to control the azimuth rotation of the tracking turntable driven by the DC brushless motor, and the servo motor drive current is used to control the pitch rotation of the tracking turntable driven by the servo motor.

[0066] Complex programmable logic devices are used to process information from peripherals and send it to the digital signal processor for processing through the external memory interface (EMIF), and then output the calculated control quantity in real time, so as to achieve the requirements of precise control and tracking of the turntable. The external memory interface (EMIF) is an interface on the DSP. The EMIF can realize the connection between the DSP and different types of memory. The EMIF is connected to the FPGA, so that the FPGA platform acts as a co-processor, a high-speed data processor or a high-speed data transmission interface.

[0067] The azimuth drive unit is used to drive the DC brushless motor of the tracking turntable, and the DC brushless motor is used to drive the tracking turntable to rotate in the azimuth direction. The pitch drive unit is used to drive the servo motor of the tracking turntable, and the servo motor drives the tracking turntable to rotate in the pitch direction.

[0068] As a preferred embodiment, the digital signal processor is provided with an external memory interface and an analog-to-digital converter (ADC); the servo control unit also includes an azimuth pulse width modulation circuit, an elevation pulse width modulation circuit, an azimuth level conversion circuit, and an elevation level conversion circuit. The analog-to-digital converter is mainly used to convert continuously transmitted analog signals into digital signals, so as to facilitate the digital system to quickly process and analyze the transmitted information. The main function of the pulse width modulation circuit (PWM) is to convert the amplitude of the input voltage into a pulse of a certain width. In other words, it converts the amplitude data into a pulse width. In addition to monitoring the output state of the power circuit, the pulse width modulation circuit also provides a power element control signal. Therefore, it is widely used in various high-power circuits such as switching power supplies with high power conversion efficiency, motor inverters, D-pole amplifiers for audio, DC-DC converters, UPS, etc.

[0069] In an embodiment of the present invention, a complex programmable logic device sends tracking data with an operating mode flag to a digital signal processor via an external memory interface; the digital signal processor uses an interrupt function to call the tracking data, generates a control quantity corresponding to the tracking data according to the operating mode flag, and writes the control quantity to the complex programmable logic device via the external memory interface; the complex programmable logic device generates an azimuth pulse width modulation signal and an elevation pulse width modulation signal corresponding to the control quantity via an azimuth pulse width modulation circuit and an elevation pulse width modulation circuit, and sends the azimuth pulse width modulation signal to the azimuth drive unit via an azimuth level conversion circuit, and sends the elevation pulse width modulation signal to the elevation drive unit via a elevation level conversion circuit.

[0070] As a preferred embodiment, the azimuth drive unit includes a DC brushless motor driver, an azimuth photoelectric isolation and a DC brushless motor drive current signal conditioning circuit, and an azimuth Hall current sensor; the pitch drive unit includes a servo motor driver, a pitch photoelectric isolation and a servo motor drive current signal conditioning circuit, and a pitch Hall current sensor. Photoelectric isolation is a device used for electrical signal isolation, which has the advantages of unidirectional transmission, electrical isolation, and strong anti-interference ability. It is mainly used in microcomputer interfaces, voltage isolation protection circuits, etc., and realizes signal transmission through electrical-optical-electrical conversion. The Hall current sensor is used to condition the current voltage signal to the voltage requirement range of the analog-to-digital converter of the digital signal processor, and then connect the signal to the analog-to-digital converter. The azimuth drive unit and the pitch drive unit respectively drive the DC brushless motor and the servo motor of the tracking turntable, and both operate independently, so the azimuth drive unit and the pitch drive unit respectively include independent photoelectric isolation (i.e., azimuth photoelectric isolation and pitch photoelectric isolation) and Hall current sensors (i.e., azimuth Hall current sensor and pitch Hall current sensor).

[0071] In an embodiment of the present invention, the azimuth photoelectric isolation receives an azimuth pulse width modulation signal sent through an azimuth level conversion circuit, the DC brushless motor driver controls the DC brushless motor according to the azimuth pulse width modulation signal, and the azimuth Hall current sensor conditions the current and voltage signals of the DC brushless motor driver to an azimuth voltage signal of 0 to 3V and then connects to an analog-to-digital converter; and / or, the pitch photoelectric isolation receives the pitch pulse width modulation signal sent through the pitch level conversion circuit, the servo motor driver controls the servo motor according to the pitch pulse width modulation signal, and the pitch Hall current sensor conditions the current and voltage signals of the servo motor driver to a pitch voltage signal of 0 to 3V and then connects to the analog-to-digital converter.

[0072] In an embodiment of the present invention, a complex programmable logic device obtains speed feedback and position feedback of the tracking turntable and sends them to a digital signal processor through an external memory interface; the digital signal processor adjusts the control amount according to the speed feedback, position feedback, azimuth voltage signal and pitch voltage signal.

[0073] The complex programmable logic device can obtain the position signal of the tracking turntable in azimuth according to the absolute code disk and incremental code disk of the tracking turntable. The complex programmable logic device can also obtain the position signal of the tracking turntable in azimuth according to the Hall of the DC brushless motor. At the same time, the complex programmable logic device can obtain the position signal of the tracking turntable in pitch angle according to the photoelectric encoder of the servo motor. The speed information and position information of the tracking turntable can be calculated according to the position signal of azimuth angle and the position signal of pitch angle, and the digital signal processor can adjust the corresponding control amount according to the speed information and position information of the tracking turntable.

[0074] Continue to refer Figure 2 , is a reference servo control system for tracking turntable. The system is developed based on DSP+FPGA architecture. DSP implements servo control algorithm and various working modes. FPGA processes peripheral information and sends it to DSP through EMIF for processing. It also outputs the control quantity solved by DSP in real time, so as to achieve the requirement of precise control of servo motor (i.e. servo motor and DC brushless motor). Among them, the chip used by DSP is TMS320F28335 produced by TI, which mainly realizes the control algorithm of azimuth and pitch direction, analog-to-digital conversion, RS422 communication and peripheral device control. FPGA adopts EP2C8Q208I8 of Cyclone II series of ALTERA, which mainly realizes functions such as logic control, code disk acquisition, motor control and external device communication. The azimuth drive unit can adopt DC brushless motor driver of Xi'an Weijing, model WBC03G, which can realize motor drive with continuous working current less than 7A. DC brushless motor driver can also obtain position signal according to the Hall of DC brushless motor. The pitch drive unit can adopt a servo motor driver of TI, model LMD18200, which can realize a DC motor drive with a continuous working current of less than 3A.

[0075] The control quantity generated by DSP is called by FPGA to generate azimuth pulse width modulation circuit (PWM1) and pitch pulse width modulation circuit (PWM2) to generate azimuth driving logic (i.e. azimuth pulse width modulation signal) and pitch driving logic (i.e. pitch pulse width modulation signal) corresponding to the control quantity, and the azimuth pulse width modulation signal is sent to the azimuth photoelectric isolation through the azimuth level conversion circuit, and the pitch pulse width modulation signal is sent to the pitch photoelectric isolation through the pitch level conversion circuit. The azimuth pulse width modulation signal output by PWM2 control is directly connected to the DC brushless motor driver WBC03G through the azimuth photoelectric isolation, and the DC brushless motor driver generates control current to drive the DC brushless motor to move. The main function of the azimuth Hall current sensor (model CC6900) is to convert the control current generated by the DC brushless motor driver into a voltage signal, and adjust it to the voltage requirement (0~3V) range of the ADC module of the DSP, and then connect the signal to the ADC module of the DSP, thereby improving the accuracy of the sampling current. The pitch pulse width modulation signal output by PWM1 control is directly connected to the servo motor driver LMD18200 through the pitch photoelectric isolation. The servo motor driver generates a control current to drive the servo motor to move. The main function of the pitch Hall current sensor (model CC6900) is to convert the control current generated by the servo motor driver into a voltage signal, and adjust it to the voltage requirement (0~3V) range of the DSP's ADC module, and then connect the signal to the DSP's ADC module.

[0076] It should be noted that the further functional realization of the aforementioned components can refer to the description of the aforementioned servo control system for a tracking turntable, which will not be repeated here.

[0077] In addition, a servo control system for a tracking turntable in an embodiment of the present invention can connect a code disk, a power supply +24V, a servo motor and a brushless DC motor through a unified servo control interface, and adopt RS422 communication. The full name of the RS422 standard is "Electrical Characteristics of Balanced Voltage Digital Interface Circuits", which defines the characteristics of the interface circuit. The typical RS-422 is a four-wire interface, full-duplex, differential transmission, and multi-point communication data transmission protocol. In fact, there is also a signal ground wire, for a total of 5 wires. It uses balanced transmission and adopts unidirectional / non-reversible transmission lines with or without enable ends. FPGA uses multiple transceivers (IL422) for communication.

[0078] It should be noted that the above introduction about the servo control interface, RS422 communication, power supply +24V, and IL422 is only to help understand the reference embodiment and does not constitute a limitation of the present invention.

[0079] Please refer to Figure 3An embodiment of the present invention provides a tracking turntable, which is controlled by the aforementioned tracking turntable servo control method or by the aforementioned tracking turntable servo control system.

[0080] The tracking turntable is mainly divided into two parts, the azimuth axis and the pitch axis. Its structure adopts a typical pitch-azimuth structure, specifically including: an azimuth seat 1, a current collector 2, a DC brushless motor (not shown in the figure), a code disc 5, a support U-shaped frame 3, a pitch package 4, a pitch axis system (not shown in the figure), a servo motor (not shown in the figure), an infrared thermal imager 7 and a visible light camera 6. The azimuth seat is sequentially equipped with a current collector 2, a DC brushless motor, a code disc 5, a support U-shaped frame 3 and a pitch package 4; the support U-shaped frame 3 is equipped with a pitch axis system and a servo motor, and is connected to the pitch package 4; the end of the servo motor is provided with a photoelectric encoder (not shown in the figure); the pitch package 4 is equipped with an infrared thermal imager 7 and a visible light camera 6.

[0081] The slip ring 2 is a connection device that realizes stable and reliable transmission of electric energy and signals between the rotating part and the fixed part of the equipment. The slip ring 2 enables the infrared thermal imager 7 and the visible light camera 6 to continuously operate 360° in the horizontal direction. At the same time, the infrared thermal imager 7 and the visible light camera 6 are installed in the supporting U-shaped frame 3 through the pitch bag 4, and can achieve a movement of +90° to -90° in the pitch direction.

[0082] A tracking turntable in an embodiment of the present invention is a hardware design based on the aforementioned servo control method for a tracking turntable or a servo control system for a tracking turntable. It is expandable and has a wide range of adaptability. For example, the infrared thermal imager 7 and the visible light camera 6 can be replaced by other measuring tools, and has important engineering application value.

[0083] Please refer to Figure 4, is a main program flowchart of a servo control system for a tracking turntable according to an embodiment of the present invention, which can be implemented by control software. The main program mainly includes two parts: initialization and cyclic operation program. Initialization includes hardware initialization, system initialization and servo system operation environment initialization. In the hardware initialization stage, the servo for the tracking turntable performs self-test after power-on, mainly reporting the angle after movement. If the end position of the movement is the initial horizontal zero degree, the self-test is normal. The cyclic operation program mainly includes a data receiving module, a servo motion control module and a data sending module called by a clock interrupt function in a timed loop. Among them, the servo motion control module is mainly based on DSP. The servo motion control module completes the functions of working mode switching, control algorithm implementation, etc. The data receiving module and the data sending module are mainly based on FPGA, level conversion circuit and PWM. The data receiving module receives tracking data such as photoelectric tracking miss amount data, hand lever information data, encoder data and display and control system data, and processes the tracking data and sets the corresponding working mode flag. The data sending module sends data to the display and control system and the servo drive unit. In order to save system resources and ensure the real-time data received by the system, the interrupt mode is used for real-time reception. The interrupt response priority is reduced from encoder data reception, hand lever information data reception, photoelectric tracking miss amount data reception, and display and control system data reception. The servo motion control module uses the interrupt function to receive data, and calls the interrupt function to receive data at an interval of 1ms. The interrupt function first determines the interrupt type, then performs the corresponding operation, and finally writes the control amount into the FPGA, and the FPGA generates the corresponding PWM control signal. To ensure system synchronization, the data sending module is called in the DSP clock interrupt function, and the DSP system clock is used to query and send data at an interval of 20ms. If there is data to be sent, it is sent every 20ms.

[0084] A servo control system for a tracking turntable in an embodiment of the present invention can realize motion control of the azimuth and pitch degrees of freedom of the tracking turntable. The azimuth control of the servo controller (i.e., the servo control system for the tracking turntable) adopts a torque motor direct drive method, and the control algorithm includes three parts: a current loop, a speed loop, and a position loop. The pitch axis is equipped with a reducer. In order to improve the stability of the angular velocity of the servo system, the pitch control adopts a full closed-loop control method of the motor end and the load end, and at the same time adopts a load end acceleration feedback method to suppress the motion error caused by the reducer.

[0085] Servo control is a necessary means to ensure high-precision and fast-response tracking of angular position and angular velocity. A typical three-loop servo control system is as follows: Figure 5As shown, it includes a position loop, a speed loop and a current loop. Among them, the input of the position loop is a pulse width modulation signal (including an azimuth pulse width modulation signal and a pitch pulse width modulation signal), a target angular position and an actual angular position fed back by a photoelectric encoder. The actual angular position is calculated by the code disk and the Hall of the servo motor to obtain the servo mechanical structure. The difference between the pulse width modulation signal and the target angular position and the actual angular position is processed by error conversion and then output after correction by the position loop. The sum of the output and the position signal constitutes the input of the speed loop. The input of the speed loop is the position signal after correction by the position loop and the feedback of the speed loop. The difference between the position signal and the feedback of the speed loop is compared and output as the azimuth pulse width modulation signal and the pitch pulse width modulation signal after error conversion by the speed loop. The feedback of the speed loop comes from the feedback value of the photoelectric encoder obtained by speed calculation. The input of the current loop is the corrected output of the position loop and speed loop (i.e., the azimuth pulse width modulation signal and the pitch pulse width modulation signal) and the feedback of the current loop. The difference between the azimuth pulse width modulation signal and the pitch pulse width modulation signal and the feedback of the current loop is processed by error conversion in the current loop and then output to the actuator motor (i.e., the servo motor and the DC brushless motor). The output of the current loop is the control current of the actuator motor. The feedback of the current loop is the Hall current sensor feedback to the current loop. Therefore, the azimuth pulse width modulation signal and the pitch pulse width modulation signal will undergo three links of correction to form the control current. The feedback element of the position loop is the encoder of the tracking turntable, the speed feedback element of the rate loop is also the encoder of the tracking turntable, and the current feedback element of the current loop is the Hall current sensor.

[0086] It should be noted that the servo control system for a tracking turntable provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the servo control system for a tracking turntable provided in the above embodiment and the servo control method embodiment for a tracking turntable belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0087] The embodiment of the present application also provides a computer device, please refer to Figure 6 The computer device includes a processor and a memory, in which at least one instruction, at least one program, a code set or an instruction set is stored, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by the processor to implement a servo control method for a tracking turntable provided in the above-mentioned method embodiments.

[0088] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement a servo control method for a tracking turntable provided in the above-mentioned method embodiments.

[0089] An embodiment of the present application also provides a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium, and the processor executes the computer program, so that the computer device executes a servo control method for a tracking turntable as described in any of the above embodiments.

[0090] For the convenience of description, the above system or device is described by dividing it into various modules or units according to its functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0091] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0092] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0093] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A servo control method for a tracking turntable, characterized in that: The method comprises: receiving tracking data, and setting a corresponding working mode flag after processing the tracking data; Using an interrupt function to call the tracking data, and generating a control amount corresponding to the tracking data according to the working mode flag; A pulse width modulation signal corresponding to the control amount is generated; wherein the pulse width modulation signal is used to control the DC brushless motor and / or the servo motor to drive the rotation of the tracking turntable.

2. The method according to claim 1, characterized in that Before receiving the tracking data, the following steps are also included: hardware initialization, system initialization and servo operating environment initialization for the servo used for the tracking turntable; The tracking data includes encoder data, hand lever information data, photoelectric tracking miss amount data, and display and control system data; receiving tracking data includes: receiving the encoder data, the hand lever information data, the photoelectric tracking miss amount data, and the display and control system data in order from high to low priority by using an interrupt mode; The method also includes: obtaining speed feedback and position feedback of the tracking turntable, an azimuth voltage signal of a brushless DC motor, and a pitch voltage signal of a servo motor; and adjusting the control amount according to the speed feedback, the position feedback, the azimuth voltage signal, and the pitch voltage signal.

3. A servo control system for a tracking turntable, characterized in that: The system is composed of a servo control unit and a servo drive unit; the servo control unit includes a digital signal processor and a complex programmable logic device; the servo drive unit includes an azimuth drive unit and a pitch drive unit; wherein, The complex programmable logic device receives the tracking data, and sets a corresponding working mode flag after processing the tracking data; and then sends the tracking data with the working mode flag to the digital signal processor; The digital signal processor uses an interrupt function to call the tracking data, generates a control amount corresponding to the tracking data according to the working mode flag, and writes the control amount into the complex programmable logic device; The complex programmable logic device generates a pulse width modulation signal corresponding to the control amount, and sends the pulse width modulation signal to the azimuth driving unit and / or the pitch driving unit; The azimuth drive unit generates a DC brushless motor drive current according to the pulse width modulation signal, and / or the pitch drive unit generates a servo motor drive current according to the pulse width modulation signal; wherein the DC brushless motor drive current is used to control the DC brushless motor to drive the azimuth rotation of the tracking turntable, and the servo motor drive current is used to control the servo motor to drive the pitch rotation of the tracking turntable.

4. The system according to claim 3, characterized in that The digital signal processor is provided with an external memory interface; the servo control unit further comprises an azimuth pulse width modulation circuit, an elevation pulse width modulation circuit, an azimuth level conversion circuit and an elevation level conversion circuit; wherein, The complex programmable logic device sends the tracking data with the working mode flag to the digital signal processor through the external memory interface; The digital signal processor uses an interrupt function to call the tracking data, generates a control amount corresponding to the tracking data according to the working mode flag, and writes the control amount into the complex programmable logic device through the external memory interface; The complex programmable logic device generates an azimuth pulse width modulation signal and an elevation pulse width modulation signal corresponding to the control amount through the azimuth pulse width modulation circuit and the elevation pulse width modulation circuit, and sends the azimuth pulse width modulation signal to the azimuth drive unit through the azimuth level conversion circuit, and sends the elevation pulse width modulation signal to the elevation drive unit through the elevation level conversion circuit.

5. The system according to claim 4, characterized in that The digital signal processor is also provided with an analog-to-digital converter; the azimuth drive unit includes a DC brushless motor driver, an azimuth photoelectric isolation and an azimuth Hall current sensor; the pitch drive unit includes a servo motor driver, a pitch photoelectric isolation and a pitch Hall current sensor; wherein, The azimuth photoelectric isolation receives the azimuth pulse width modulation signal sent by the azimuth level conversion circuit, the DC brushless motor driver controls the DC brushless motor according to the azimuth pulse width modulation signal, and the azimuth Hall current sensor adjusts the current voltage signal of the DC brushless motor driver to an azimuth voltage signal of 0 to 3V and then connects to the analog-to-digital converter; and / or, The pitch photoelectric isolation receives the pitch pulse width modulation signal sent by the pitch level conversion circuit, the servo motor driver controls the servo motor according to the pitch pulse width modulation signal, and the pitch Hall current sensor conditions the current voltage signal of the servo motor driver to a pitch voltage signal of 0 to 3V and then connects to the analog-to-digital converter.

6. The system according to claim 5, characterized in that The complex programmable logic device obtains the speed feedback and the position feedback of the tracking turntable and sends them to the digital signal processor through the external memory interface; The digital signal processor adjusts the control amount according to the speed feedback, the position feedback, the azimuth voltage signal and the pitch voltage signal.

7. A tracking turntable, characterized in that: The tracking turntable is controlled by the method described in any one of claims 1 to 2 or by the system described in any one of claims 3 to 6. The tracking turntable comprises: an azimuth seat (1), a slip ring (2), a brushless DC motor, a code disc (5), a supporting U-shaped frame (3), a pitch package (4), a pitch axis system, a servo motor, an infrared thermal imager (7) and a visible light camera (6), wherein: The azimuth seat (1) is provided with the merge ring (2), the DC brushless motor, the encoder (5), the supporting U-shaped frame (3) and the pitch bag (4) in sequence; The pitch axis system and the servo motor are installed in the support U-shaped frame (3), and the pitch package (4) is connected; wherein the end of the servo motor is provided with a photoelectric encoder; The pitch package (4) is equipped with the infrared thermal imager (7) and the visible light camera (6).

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the steps of any of the methods described in claims 1-2 above.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 2 are implemented.

10. A computer program product, characterized in that The method comprises a computer program, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 2 are implemented.

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