High-precision turntable control system for laser communication terminal

Abstract

The invention discloses a high-precision turntable control unit for an inter-satellite laser communication terminal and an anti-interference method of the high-precision turntable control unit in a composite environment. The system comprises a main control module, a power supply module, a communication interface module, a motor driving module, an encoder acquisition module and an unlocking module, and the main control module, the power supply module, the communication interface module, the motor driving module, the encoder acquisition module, the unlocking module and the like are subjected to multi-stage power supply protection, signal isolation, magnetic shielding and redundancy design; according to the invention, the anti-interference capability, the fault-tolerant capability and the environmental adaptability of the system are effectively improved, and the high-reliability operation of the system in a complex space and an industrial environment is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of laser communication terminals and high-precision turntable control thereof, and in particular to a high-precision turntable control system for laser communication terminals. Background Art

[0002] In intersatellite laser communication systems, the turntable control system is the core component for achieving accurate light beam alignment. Its performance directly determines the stability of the communication link and the data transmission rate. This type of control system usually needs to complete precise driving and status feedback of multi-axis motors, while also needing to exchange data with multiple external communication devices and ensure reliability and stability in complex electromagnetic environments.

[0003] Existing turntable control systems have limitations in terms of structural integration, power supply protection, anti-interference capabilities, and motion control accuracy. For example, signal processing and coordinated control between different modules need improvement. Power management and protection circuits may not be able to ensure continuous and stable operation of each unit over long periods of time or under extreme conditions. Some systems also lack structural protection and operational maintenance convenience during equipment shutdown or state switching. These issues have, to a certain extent, impacted the turntable's accuracy, reliability, and system maintenance efficiency.

[0004] In view of the above problems, it is still necessary to further optimize the structure and functional design of related systems to improve the comprehensive performance of laser communication terminal turntable control. Summary of the Invention

[0005] In order to overcome the existing problems and defects, the present invention proposes a high-precision turntable control system for a laser communication terminal, which is characterized by comprising:

[0006] The main control module is used to receive external control instructions, process data, and output motor control signals;

[0007] Power supply module, used to provide working power for each functional module of the core control board;

[0008] Communication interface module, used for data communication with external devices to realize the sending and receiving of instructions and data;

[0009] The motor drive module is used to drive the azimuth and pitch axis motors of the turntable according to the control signal output by the main control module;

[0010] The encoder acquisition module is used to collect the position signals of the azimuth axis and pitch axis, and feed the signals back to the main control module to achieve closed-loop control;

[0011] The unlocking module is used to unlock the locking structures of the azimuth axis and pitch axis.

[0012] The main control module, communication interface module, motor drive module, encoder acquisition module and unlocking module are powered by power modules respectively. The main control module is connected to the communication interface module, encoder acquisition module and motor drive module through signals to achieve high-precision control of the turntable.

[0013] Furthermore, the main control module adopts the STM32F205RGT6 microcontroller chip. The main control chip is equipped with an external active crystal oscillator circuit and a reset circuit, and has an SWD debugging interface and a BOOT configuration pin. The main control chip pins are respectively connected to the PWM control signals of the azimuth and pitch axis motors, the encoder acquisition signals and the unlocking module control signals, and are connected to the communication interface module through the UART interface.

[0014] Furthermore, the power supply module includes a 12V input terminal, an overcurrent protection resistor and a P-channel MOS tube in series for reverse connection prevention, a TVS transient suppression diode and a capacitor in parallel for surge suppression and filtering, and an output terminal that generates 5V and 3.3V power supplies through an LDO voltage regulator chip to power the main control module, drive module, communication interface module and encoder acquisition module respectively.

[0015] Furthermore, the communication interface module is an RS422 differential communication transceiver circuit, which includes an RS422 chip, terminal matching resistors and isolation circuits to achieve differential data communication with an external control unit. The communication signal is connected to the main control module through a UART interface.

[0016] Furthermore, the motor drive module includes two groups of DRV8305 or DRV8306 driver chips and multiple groups of N-channel MOS tubes. Each group of driver chips controls a three-phase brushless motor. The PWM signal output by the main control module is input to the driver chip, and the corresponding three-phase MOS tubes control the U, V, and W three-phase outputs respectively, and a current detection resistor is connected in series in each phase current path to realize current sampling.

[0017] Furthermore, the encoder acquisition module includes an RS422 differential signal receiving chip and a filtering circuit, which are used to collect the position signals of the azimuth and pitch axis encoders. The RS422 differential input end is connected in series with a terminal matching resistor, and the output end is connected to the dedicated interface pin of the main control module through a signal line to achieve high-precision position feedback of the azimuth and pitch axes.

[0018] Furthermore, the unlocking modules are set for the azimuth axis and pitch axis respectively, and their unlocking circuits include a P-channel MOS tube, an NPN transistor and a voltage divider resistor network. The 12V power supply is output to the unlocking end of each axis through the P-channel MOS tube. The gate of the MOS tube is driven by the collector of the NPN transistor, the emitter of the transistor is grounded, and the base is connected in series with a current-limiting resistor and connected to the unlocking control signal of the main control module to realize independent unlocking control of the azimuth axis and pitch axis locking structure.

[0019] Furthermore, the main control module, power supply module, encoder acquisition module, communication interface module and motor drive module include at least one or more of the following protection measures:

[0020] The power input is equipped with a self-recovery fuse and transient suppression diode for overcurrent and surge protection;

[0021] The acquisition and control signal channels use photoelectric isolation or multi-layer PCB isolation to enhance anti-interference capabilities;

[0022] Key analog / digital circuits are physically partitioned and magnetic shielding structures are set up in sensitive areas to improve electromagnetic compatibility.

[0023] Beneficial effects of the present invention:

[0024] The present invention realizes the compactness and unification of the system structure and improves the overall stability and reliability through the highly integrated design of multiple functional modules such as main control, power supply, communication interface, motor drive, encoder acquisition and unlocking. The adoption of measures such as multi-level power supply protection and differential signal acquisition effectively enhances the anti-interference ability and power supply stability of the system. The main control chip has strong data processing capabilities and can realize real-time and precise control and status feedback of multi-axis motors, significantly improving the accuracy and response speed of motion positioning. The rich communication interface not only ensures efficient interconnection with the host computer and other external devices, but also facilitates the expansion and engineering application of the system. By setting up a dedicated unlocking module, the safe locking and flexible unlocking of each moving axis of the turntable can be achieved, further improving the operational safety and maintenance convenience of the equipment, thereby effectively meeting the actual needs of the laser communication terminal for high-precision control of the turntable.

[0025] By implementing multi-level power protection, signal isolation, magnetic shielding, and redundant design in modules such as the main control, power supply, communication interface, motor drive, encoder acquisition, and unlocking, the present invention effectively enhances the system's anti-interference capability, fault tolerance, and environmental adaptability, ensuring highly reliable operation of the system in complex spaces and industrial environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 A schematic diagram of the composition of a turntable control system unit provided in one embodiment of the present invention;

[0028] Figure 2A schematic diagram of a motor main control module provided by an embodiment of the present invention;

[0029] Figure 3 A schematic diagram of a control board power module provided in one embodiment of the present invention;

[0030] Figure 4 A block diagram of power distribution for a control panel provided in one embodiment of the present invention;

[0031] Figure 5 A schematic diagram of a turntable motor drive board provided in one embodiment of the present invention;

[0032] Figure 6 A diagram showing a processor communication principle according to an embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the unlocking module of a turntable system provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present application is described below with reference to specific embodiments:

[0035] Example 1:

[0036] The present invention provides a high-precision laser communication terminal turntable control system, which is described in detail below in conjunction with a specific circuit structure:

[0037] like Figure 1 As shown, the control system mainly includes: a main control module, a power management module, a motor drive module, an encoder acquisition module, a communication interface module and an unlocking module.

[0038] (1) Main control module:

[0039] like Figure 2As shown, the main control module of this embodiment is based on the STM32F205RBT6 microcontroller U1, which realizes centralized control and coordination of various system functions. The power supply of the main control chip U1 is powered by an external stable 3.3V power supply through ports such as VBAT, VDD, and VDDA. Multiple high-frequency decoupling capacitors such as C14, C15, C16, and C17 are respectively configured between VBAT, VDD, and GND to suppress power ripple and improve anti-interference capabilities. At the same time, 2.2μF / 50V capacitors C18 and C19 are connected to the V_CAP1 and V_CAP2 pins respectively to support the working stability of the internal modules. Each group of I / O ports of U1 supports high-speed communication with peripheral devices through multiple serial interfaces such as UART1 and UART4, and is connected to the external control signal port respectively. The reset circuit of the chip is composed of R25 pull-up resistor and C22 decoupling capacitor to ensure that the circuit can reset smoothly when powered on without glitch triggering. The debug interface (H7) uses standard SWD signals (SWDIO, SWCLK, and NRST) and is compatible with mainstream JTAG emulators, facilitating both software and hardware development and production debugging. The system clock uses an active crystal oscillator X1 and its matching capacitors C20 and C21 to provide a high-precision master clock signal, which is input to the STM32 controller via the OSC_IN / OSC_OUT ports, ensuring stable system timing and peripheral synchronization. The controller's BOOT0 pin is pulled up to 3.3V via resistor R24. Combined with the H6 test terminal, this pin allows users to flexibly select the chip's boot mode, facilitating system programming and maintenance.

[0040] The above circuit distributes the main control power and signal interfaces, and adopts multi-point filtering, voltage regulation and pull-up configuration, which effectively improves the anti-interference ability and system operation stability, ensures the reliable operation of the main control module under complex working conditions, and provides a solid control and communication foundation for the entire control system.

[0041] (2) Power management module

[0042] like Figure 3-4 The power management module in this embodiment is based on a 12V DC power input and integrates multiple functions such as overcurrent protection, reverse connection protection, power supply voltage reduction and voltage stabilization.

[0043] First, a resettable fuse F1 is set at the input end to implement input overcurrent protection. Next, a MOS tube Q1 and its peripheral resistor devices are used in the input path to build an anti-reverse connection circuit, which effectively prevents damage to the system when the positive and negative poles of the power supply are reversed. Compared with the traditional diode anti-reverse connection solution, it has a lower series voltage drop and higher efficiency. After being filtered by high-frequency decoupling capacitors and other filters, the 12V input enters the main step-down conversion unit. This part is centered on chip U8 and works in conjunction with energy storage inductor L1, Schottky rectifier diode D9, and multiple input and output decoupling capacitors to achieve 12V to 5V step-down conversion. In the 5V output path, a resettable fuse F2 and TVS tube D8 are further connected in series to provide secondary overcurrent and overvoltage protection, effectively ensuring load safety. At the same time, a TEST test terminal is reserved for power supply testing and subsequent debugging. To meet the lower supply voltage requirements of some key functional units, the power management module further regulates the 5V output to 3.3V (3V_TEST) using linear voltage regulator chip U3. Large-capacity ceramic capacitors are placed at the regulator's input and output to enhance filtering and dynamic response. Throughout the power management module, every power supply level fully considers stability, power quality, and system safety requirements. Multi-level decoupling and hierarchical protection effectively enhance anti-interference capabilities and operational reliability, providing a safe, stable, and high-quality operating power supply for the main control unit and various functional circuits.

[0044] (3) Motor drive module

[0045] like Figure 5 As shown, the driver module of this embodiment adopts a three-phase drive architecture with DRV8306HRSMT as the core and three sets of full-bridge power MOSFETs as actuators. The specific structure is as follows:

[0046] The drive module includes three complete bridge arms. Each bridge arm consists of two N-channel MOSFETs connected in series as upper and lower bridge arms, totaling six MOSFETs. The midpoints of the three bridge arms are connected to the A, B, and C phase windings of the motor respectively, realizing on-off commutation and efficient drive of the three-phase motor.

[0047] The DRV8306HRSMT chip's three driver output ports (GHA, GHB, and GHC) are connected to the gate terminals of each pair of MOSFETs in the three full-bridges. This provides accurate on / off control signals for each MOSFET, enabling high-speed and efficient switching of the bridge arms according to the PWM or commutation logic generated by the main control chip. Furthermore, the driver chip's IDRIVE pin is connected to ground via external resistors (such as R5 and R7). Depending on the resistance value, the MOSFET's on / off gate current range is automatically set to match different power transistor specifications, improving switching speed, EMI performance, and system reliability.

[0048] A current sampling resistor (such as R8-R12, 220mΩ) is placed between the source and ground of the lower-side MOSFET of each bridge arm to sample the current in each phase circuit. The DRV8306HRSMT chip features a built-in current sampling function. By monitoring the tiny voltage across the resistor, it enables real-time monitoring of the operating current of each phase, providing overcurrent and short-circuit protection responses, ensuring safe and stable operation of the motor drive system.

[0049] Appropriate decoupling capacitors (such as C1 and C2) are also configured on the periphery to stabilize the power supply of the driver chip and the full-bridge power circuit, and to filter and reduce noise in the power circuit and control section. The above structure achieves signal and power separation, simplifying system design and maintenance.

[0050] (4) Encoder acquisition module and communication interface module

[0051] Figure 6 An embodiment of a signal acquisition and communication interface module is presented. The module is based on the AM26LV32EMDREP differential line receiver chip and peripheral components to implement highly reliable reception, isolation, and standard output of differential signals from external encoders or sensors.

[0052] like Figure 6 As shown, this module features multiple differential signal input channels (such as FW_CODE_RX_P / N, GD_CODE_RX_P / N, and RS422 RX_P / N). Each channel's signal first passes through matching resistors (such as R32 and R39) to achieve current limiting, crosstalk mitigation, and common-mode noise suppression before being input to the corresponding differential inputs of the AM26LV32EMDREP chip. The AM26LV32EMDREP integrates four high-speed differential receivers that convert RS422 differential signals into standard TTL / CMOS digital signals. These received signals are then transmitted through the chip's digital outputs as standard single-ended digital signals, such as PW_CODE_TX, GD_CODE_TX, and RS_CODE_TX, facilitating direct data acquisition and subsequent data processing by the main control unit.

[0053] (5) Unlock module

[0054] Figure 7 discloses an electronically controlled unlocking module for the azimuth and pitch axes of a device. Its structure, as shown in the figure, includes two essentially identical unlocking circuits, one for the azimuth and one for the pitch axis. Each unlocking circuit uses a field-effect transistor and a transistor as the primary switching control elements to precisely on-off the external 12V power supply, thereby driving a motor or electromagnetic lock body to complete the mechanical unlocking action.

[0055] Taking the azimuth axis unlocking circuit as an example, the main control unit transmits the UnLOCK_FW control signal through current-limiting resistor R17 and inputs it to transistor Q4 (MMBT3904LT1HTSA1). When the UnLOCK_FW signal outputs a high level, Q4 turns on, and the gate of Q2 is released to ground through voltage-divider resistors R16 and R20. Q2 then turns on, connecting the 12V_M main power supply to the UnLOCK_F port, thereby unlocking the actuator. The pitch axis unlocking circuit structure is the same as described above. The main control unit outputs the UnLOCK_GD signal, which drives Q8 and Q3 to conduct, establishing a path from the 12V_M main power supply to UnLOCK_GD, thereby controlling the pitch axis unlocking action.

[0056] This unlocking module offers simple control logic, quick response, and strong output capability. It utilizes MOSFETs for efficient power drive, preventing high current from directly acting on the main control port, thereby improving system safety and reliability. Each control signal path is equipped with appropriate current limiting and pull-down resistors to effectively prevent malfunctions caused by signal interference or accidental triggering.

[0057] Example 2:

[0058] To ensure the long-term stable operation of this system under high-intensity electromagnetic interference, high-energy particle radiation and complex space environments, the present invention implements multi-level protection and fault-tolerant design for each functional module. Specific measures include:

[0059] Power module protection measures: All power input terminals are connected in series with resettable fuses to prevent overcurrent caused by external short circuits and power supply anomalies. A TVS is connected in parallel with the main power circuit to suppress surge spikes from the power supply network. Large-capacity aluminum electrolytic and tantalum capacitors are used in the power input downstream stage to filter out residual high-frequency interference and power supply pulse noise. Current-limiting resistors and ceramic capacitors are connected in series with the DC-DC output to further reduce high-frequency interference and improve power supply stability.

[0060] PCB and signal protection: The main control board and acquisition circuits utilize four or more layers of PCB, with extensive grounding on the top and bottom layers. The analog and digital signal areas are independently isolated, and key signal lines are embedded with ground rings to significantly suppress crosstalk within the PCB. All weak signal acquisition terminals utilize high-speed optoelectronic isolation chips, physically isolating each channel between the main control and external ports, effectively preventing malfunctions caused by common ground or ground potential differences.

[0061] Magnetic shielding measures for key components of the module: Tantalum metal shielding layer is used for highly sensitive components such as differential signal amplifiers, precision A / D acquisition chips, and clock oscillators to perform local envelope shielding on areas susceptible to magnetic field interference; MnZn ferrite magnetic ring filters are installed at the entry and exit interfaces of power devices and motor power supply harnesses to effectively suppress high-frequency magnetic field interference in space.

[0062] Overvoltage and overcurrent fault tolerance and redundancy design: All signal ports are equipped with parallel electrostatic suppression diodes (such as PESD2CAN and SMAJ12CA) to prevent electrostatic discharge damage. All power branches use segmented fuses, and important branches are equipped with indicating fuses to facilitate rapid fault location and segmented restart. Certain critical signal links are equipped with series capacitors and parallel voltage divider resistors based on actual needs to prevent signal spikes and provide a certain degree of current limiting protection.

[0063] Communication and power supply bus redundancy and isolation: Data links such as the CAN bus and RS485 all adopt a dual-channel redundant structure, with one channel for primary use and one channel for backup, and are physically isolated by a magnetic isolation transformer. The motor power supply channel adopts a relay switching redundancy design, which supports rapid switching when a single channel fails without affecting the continuous operation of core equipment.

[0064] Module-level independence and maintainability: All core functional modules adopt independent daughterboard designs that are pluggable or screw-fastened. The interfaces are equipped with anti-error positioning and shielded shells to facilitate independent removal and replacement during maintenance. They can also be powered off and hot-swapped individually to ensure stable operation of subsystems outside the fault isolation zone.

[0065] Through the layered integrated implementation of the above-mentioned specific protection measures, the system is guaranteed to be able to perform high-precision control and communication safely, stably and without errors in typical complex environments such as electromagnetic disturbance, radiation, electrostatic discharge, power supply anomalies and mechanical shock, greatly improving the system reliability and engineering practical value.

[0066] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that ordinary relevant personnel in this technical field can make several improvements and modifications without departing from the principles of the present invention. Such improvements and modifications should also be considered as the scope of protection of the present invention.

[0067] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A high-precision turntable control system for laser communication terminals, characterized in that: include: The main control module is used to receive external control instructions, process data, and output motor control signals; A power supply module, used to provide working power to each functional module of the core control board; Communication interface module, used for data communication with external devices to realize the sending and receiving of instructions and data; The motor drive module is used to drive the azimuth and pitch axis motors of the turntable according to the control signal output by the main control module; The encoder acquisition module is used to collect the position signals of the azimuth axis and pitch axis, and feed the signals back to the main control module to achieve closed-loop control; The unlocking module is used to unlock the locking structures of the azimuth axis and pitch axis. The main control module, communication interface module, motor drive module, encoder acquisition module and unlocking module are respectively powered by the power supply module. The main control module is connected to the communication interface module, encoder acquisition module and motor drive module through signals to achieve high-precision control of the turntable.

2. The control system according to claim 1, characterized in that: The main control module adopts the STM32F205RGT6 microcontroller chip. The main control chip is equipped with an external active crystal oscillator circuit and a reset circuit, and has an SWD debugging interface and a BOOT configuration pin. The main control chip pins are respectively connected to the PWM control signals of the azimuth and pitch axis motors, the encoder acquisition signal and the unlocking module control signal, and are connected to the communication interface module through the UART interface.

3. The control system according to claim 1, characterized in that: The power supply module includes a 12V input end, an overcurrent protection resistor and a P-channel MOS tube in series for reverse connection prevention, a TVS transient suppression diode and a capacitor in parallel for surge suppression and filtering, and an output end that generates 5V and 3.3V power supplies through an LDO voltage regulator chip to power the main control module, drive module, communication interface module and encoder acquisition module respectively.

4. The control system according to claim 1, characterized in that: The communication interface module is an RS422 differential communication transceiver circuit, which includes an RS422 chip, terminal matching resistors and an isolation circuit to realize differential data communication with an external control unit. The communication signal is connected to the main control module through a UART interface.

5. The control system according to claim 1, characterized in that: The motor drive module includes two sets of DRV8306HRSMT driver chips and multiple sets of N-channel MOS tubes. Each set of driver chips controls a three-phase brushless motor. The PWM signal output by the main control module is input into the driver chip. The corresponding three-phase MOS tubes control the U, V, and W three-phase outputs respectively. A current detection resistor is connected in series in each phase current path to realize current sampling.

6. The control system according to claim 1, characterized in that: The encoder acquisition module includes an RS422 differential signal receiving chip and a filtering circuit, which is used to collect the position signals of the azimuth and pitch axis encoders. The RS422 differential input end is connected in series with a terminal matching resistor, and the output end is connected to the dedicated interface pin of the main control module through a signal line to achieve high-precision position feedback of the azimuth and pitch axes.

7. The control system according to claim 1, characterized in that: The unlocking modules are respectively set for the azimuth axis and the pitch axis, and their unlocking circuits include a P-channel MOS, an NPN transistor and a voltage divider resistor network. The 12V power supply is output to the unlocking end of each axis through the P-channel MOS transistor. The gate of the MOS transistor is driven by the collector of the NPN transistor, the emitter of the transistor is grounded, and the base is connected in series with a current-limiting resistor and connected to the unlocking control signal of the main control module to realize independent unlocking control of the azimuth axis and pitch axis locking structures.

8. The control system according to any one of claims 1 to 7, characterized in that: The main control module, power supply module, encoder acquisition module, communication interface module and motor drive module include at least one or more of the following protective measures: The power input is equipped with a self-recovery fuse and transient suppression diode for overcurrent and surge protection; The acquisition and control signal channels use photoelectric isolation or multi-layer PCB isolation to enhance anti-interference capabilities; Key analog / digital circuits are physically partitioned and magnetic shielding structures are set up in sensitive areas to improve electromagnetic compatibility.

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