Three-channel intelligent motor servo driving system and method based on SOC

Abstract

The invention mainly relates to a design scheme of a three-channel intelligent motor servo driving module based on an SOC, and belongs to the technical field of integrated circuits and micro electro mechanical systems. The system is technically characterized in that the system comprises functional circuits such as an SOC, an AD acquisition circuit, a DDR3 memory, a serial Nor Flash memory, a power conversion circuit, an RS-422 communication circuit, a signal isolation circuit and a three-path power drive circuit, and servo control over different load motors such as a brushless direct current motor and a permanent magnet synchronous motor is achieved. According to the invention, a high-performance line topology structure of "core SOC + 512Mbit FLASH + 8Gbit DDR3 + 6 channel AD acquisition + three-phase power driving" is adopted, multiple protection functions are provided, bus under-voltage and over-voltage protection and driving over-current protection functions are covered, and a fault output function is provided at the same time. The problems of application requirements of intelligence, high performance, generalization and the like of the existing military servo driving system are solved, and the system has important practical significance on improvement of performance indexes of the servo driving system and military high-reliability occasion application.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits and micro-electromechanical systems, and in particular relates to a three-channel intelligent motor servo drive system and method based on SOC. Background Art

[0002] In recent years, integrated circuit and micro-electromechanical system technologies have developed rapidly. High performance, high redundancy, high integration, and high quality reliability have become the important development direction of military servo systems. At present, most domestic servo drives use core processors such as DSP or ARM for calculation and processing. The control system has performance bottlenecks and is difficult to meet the needs. For example, data processing, mathematical operations, signal acquisition, and instruction execution often use processors in a time-sharing manner under the call of the system, resulting in performance bottlenecks in the system. In addition, traditional servo systems are mostly series systems, which make it difficult to ensure the reliability and robustness of the application. Once any link fails, it will cause serious property and even personnel losses. Summary of the invention

[0003] The present invention provides a three-channel intelligent motor servo drive system and method based on SOC to solve the technical problems existing in the prior art that the control system is quiet, the performance is difficult to meet, and the traditional servo systems are mostly connected in series, which easily leads to chain failures.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: A three-channel intelligent motor servo drive system based on SOC, comprising: AD current acquisition module, used to convert the acquired phase current analog signal into parallel digital signal data; The SOC processing module is used to calculate and process the parallel digital signal data to output the motor control digital signal, output the motor control digital signal, realize the communication transceiver function, and store the motor status information and fault information; The power drive module is used to control the opening and closing of the three-phase bridge according to the motor control signal, thereby controlling the operation of the motor; The power conversion module is used to convert the control power into three power supplies, one of which is used to supply power to the SOC processing module, and the other two are used to supply power to the power drive module.

[0005] The power conversion module includes a Π-type filter, a PWM controller and a transformer. The power conversion module converts the control power into an isolated three-way power supply through the PWM controller and the transformer.

[0006] One of the three power supplies converted by the power conversion module acts on the SOC processing module through a four-channel regulator, and the remaining two power supplies act on the power drive module.

[0007] The power driving module includes a digital isolator, one end of which is connected to the SOC processing module. The digital isolator receives the motor control digital signal output by the SOC processing module and outputs the motor control analog signal.

[0008] The power drive module also includes a power driver, one end of the power controller is connected to the other end of the digital isolator, the other end of the power controller is connected to the three-phase bridge, the power driver receives an analog signal and outputs a three-phase bridge gate control signal, and the three-phase bridge gate control signal controls the opening and closing of the three-phase bridge.

[0009] The three-channel intelligent motor servo drive system also includes a power conversion module, which is used to convert the control power supply into three power supplies and act on the SOC processing module and the power drive module.

[0010] The three-channel intelligent motor servo drive system includes three power drive modules, and each of the three power drive modules is connected to an AD current sampling module.

[0011] The three-channel intelligent motor servo drive system also includes an RS422 communication module, and the RS422 communication module is connected to the SOC processing module.

[0012] A three-channel intelligent motor servo drive method based on SOC, comprising the following steps: Step 1: The AD current acquisition module collects the A-phase current and the B-phase current from the motor, and converts the two phase currents into parallel digital signals and outputs them to the SOC processing module; Step 2: After the parallel digital signals are processed and calculated in the SOC processing module, the motor control digital signals are output, and the SOC processing module sends the motor control digital signals to the power drive module; Step 3: The power drive module converts the motor control digital signal into a motor control signal, and controls the operation of the motor according to the motor control signal.

[0013] The motor control digital signal output by the SOC processing module is a PWM control signal. Each channel power drive module receives 6 PWM control signals respectively to control the shutdown of the three-phase bridge.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a three-channel intelligent motor servo drive system based on SOC. By integrating an AD current acquisition module with a high-performance SOC processing module, the system can process the motor phase current analog signal in real time and accurately, convert it into parallel digital signal data, and then output the motor control digital signal. This design shortens the delay of signal processing, improves the execution efficiency of the control algorithm, makes the motor respond faster, and has higher control accuracy, which can better meet the needs of high-performance motion control and effectively improve the reliability and stability of the motor servo drive system.

[0015] Furthermore, a Π-type filter is used in the power conversion module to effectively filter out power supply noise, ensure power supply quality, improve the anti-interference ability of the entire system, and ensure the stable operation of the system.

[0016] Furthermore, the multi-channel power supply design of the power conversion module supplies power to the SOC processing module and the power driving module separately, especially providing an independent and stable power supply for the SOC processing module, ensuring the stable operation of the processor under high load and optimizing system performance.

[0017] Furthermore, the use of digital isolators in the power drive module establishes electrical isolation between the SOC processing module and the power drive module, preventing noise from the high-power part from interfering with the control circuit and enhancing system stability.

[0018] Furthermore, the SOC processing module integrates advanced algorithm processing capabilities, which can quickly and accurately process the signals from the AD current acquisition module and output motor control digital signals, thereby improving control accuracy and dynamic response speed.

[0019] Furthermore, the SOC processing module is connected to a three-channel power drive module. Each channel is equipped with an independent power drive module and AD current acquisition module. Compared with the traditional series structure, even if a channel fails, other channels can still work normally, effectively avoiding the chain effect of failures, improving the reliability and fault tolerance of the system, and avoiding the phenomenon of chain failures caused by failures in any link.

[0020] Furthermore, the addition of the RS422 communication module enables the system to perform real-time monitoring and fault diagnosis, quickly respond to and handle problems, and reduce downtime and maintenance costs.

[0021] Furthermore, the design of 6-channel PWM control signals provides fine control for each phase of the motor, which not only improves the control accuracy of the motor, but also increases the adaptability and flexibility of the system under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the principle block diagram of the intelligent motor control module; Figure 2 The signal conversion principle block diagram of the AD current acquisition module Figure 3 RS422 communication principle block diagram Figure 4 It is the clock and reset logic block diagram of the power conversion module; Figure 5 This is the principle block diagram of the power drive part. DETAILED DESCRIPTION

[0023] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0024] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the AD chip collects the phase current of the AC synchronous motor. The collected phase current includes the A phase current and the B phase current. After the collected phase current is processed and calculated by the core SOC, the PWM control signal is output. The core SOC is connected to a three-channel power drive circuit. The power drive circuit of each channel receives six PWM control signals. The six PWM control signals pass through the digital isolator and the power driver to output the motor control signal to control the opening and closing of the three-phase bridge, thereby realizing the control of the AC synchronous motor. The 28V control power supply is filtered by a π-type filter and then uses a PWM controller to realize the power conversion of isolated 5V and isolated 20V. The isolated 5V is converted by a 4-channel regulator to realize the power conversion of 1.0V, 1.5V, 1.8V, and 3.3V to power the core SOC. The isolated 20V is further converted into analog 5V and analog 15V power. The analog 5V power supply is used to power the digital isolator, the analog 15V is used to power the power driver, and the 28V power supply is directly powered by the three-phase bridge. RS422 communication and the host computer receive and send communication signals to the nine-way serial data transceiver through the core SOC for signal interaction.

[0026] like Figure 2 As shown in the figure, the signal conversion principle block diagram in the AD current acquisition module. The AD conversion circuit uses the AD7606 digital converter of ADI Company to realize the data conversion processing of 6-way phase current signals, connects the control signals CONVSTA and CONVSTB of the converter together, and collects 6-way analog input signals simultaneously. The 6-way phase current signals are converted into digital signals through comparators and other circuits in the AD7606 digital converter, and 16 parallel output data are output to the SOC core processor.

[0027] like Figure 3 As shown, the RS422 communication principle block diagram, The RS422 communication circuit adopts the RS422 asynchronous transceiver interface, which is implemented in the FPGA of the PL end using the UART IP core, and adds appropriate buffers and control logic to achieve autonomous asynchronous serial communication. In order to increase the versatility of the system, the UART core input clock is set to 29.4912Mhz and 30Mhz in the design. The communication rate can be adjusted between 38.4K, 115.2K, 153.6K, 614.4K and other baud rates, and the frame format can be received and determined according to the frame header and frame length. The RS422 communication principle block diagram is shown in the figure. Figure 3 shown.

[0028] like Figure 4 As shown in the figure, the principle block diagram of the clock and reset circuit in the power conversion module. The PGOOD pin of the 3.3V voltage output of the four-channel power regulator LTM4644 is connected to the reset pin of the PS end of the SOC to reset and release the PS end, and the reset of the PL end is given by the PS end. The main clock of the PS end of the SOC is provided by a 33.3MHz crystal oscillator, the main clock of the PL end is provided by the PS end, and the asynchronous RS422 logic module is provided by a 40MHz crystal oscillator.

[0029] like Figure 5 As shown, the principle block diagram of the power drive circuit, in the three-channel power drive circuit of the present invention, the principle topology of each channel is exactly the same, so only one channel is illustrated. After the six-channel PWM drive signals (AH, AL, BH, BL, CH, CL) are isolated from the digital signal and the analog signal by the digital isolator, the output signal is sent to the controller. The drive controller can not only drive the three-phase bridge power circuit through the bootstrap circuit, but also has a stable output and a fault output function, which can cut off the output of the signal in time when a fault occurs. The VDMOS tube uses a MOSFET with a withstand voltage VDSS of 200V, a current ID of 45A, and an on-resistance RDS of 28mΩ, which meets the needs of most low-voltage drive occasions.

[0030] This embodiment provides a three-channel intelligent motor servo drive system and method based on SOC, which integrates multiple key links such as power conversion, current acquisition, signal processing and power drive control. The specific implementation steps are as follows: The system uses two 28V power inputs, one 28V control power supply is used to supply the digital isolator, power driver and SOC processing module in the power drive, and the other 28V power supply is directly supplied to the three-phase bridge. Among them, the 28V control power supply is first subjected to noise suppression by a π-type filter to ensure the purity of the power supply, which is particularly important for precision control. After that, a PWM (pulse width modulation) controller is used for power conversion to achieve the conversion from 28V to isolated 5V and isolated 20V. This design ensures the electrical isolation between the control circuit and the power circuit, and improves the stability and safety of the system. The isolated 5V power supply is further converted to multiple voltages such as 1.0V, 1.5V, 1.8V, and 3.3V through the four-channel power regulator LTM4644, providing the system's core SOC (System on Chip) with the required power supply of different voltage levels to support its efficient operation. The isolated 20V power supply is converted into analog 5V and analog 15V to power the digital isolator and power driver to meet the power requirements of different parts.

[0031] The AD current acquisition module uses the high-precision AD7606 digital converter of ADI Company, which is responsible for real-time monitoring and acquisition of the A-phase current and B-phase current of the motor, and realizes the data conversion processing of the phase current signal. The AD conversion resolution is 16 bits, with serial output, byte parallel output and 16-bit parallel output mode. The input range can be configured to -5V~+5V or -10V~+10V. The present invention is configured to -5V~+5V, 16-bit data parallel output mode. The conversion rate of each ADC conversion is not more than 5μs. The control signals CONVSTA and CONVSTB of the converter are connected together, and the 6-way analog input signals are collected simultaneously. The conversion time is not more than 5us. After the AD current collects the phase current, it converts the phase current into parallel current signal data and sends it to the SOC processing module.

[0032] The SOC processing module is equipped with a high-performance programmable PSOC chip from XILINX, which integrates a processing system (PS) and programmable logic (PL) based on a quad-core high-performance processor with rich features. The core SOC, as the brain of the system, is responsible for processing the phase current signals collected from the AD (analog-to-digital converter) chip. These signals reflect the actual operating status of the motor, and after complex algorithm calculations inside the SOC, accurate motor control digital signals are output. Specifically, the SOC generates three-channel motor control signals, each channel contains 6 PWM signals, which are the key to precise motor control and are used to adjust the motor's performance parameters such as speed and torque. The SOC processing module sends the output motor control digital signal to the power drive module.

[0033] The power drive module includes a digital isolator, a power driver, and a three-phase bridge. The digital isolator receives the motor control digital signal from the SOC, and safely isolates and converts it into a motor control analog signal through photoelectric or magnetic coupling technology, avoiding interference problems that may be caused by direct driving of power devices by digital signals. Subsequently, the power driver outputs precise three-phase bridge gate control signals based on the analog signal to control the switching logic of the three-phase bridge, such as Figure 5 As shown, the motor is driven to run efficiently and smoothly.

[0034] The RS422 communication module includes an RS422 communication circuit, an RS422 communication circuit, and an RS422 asynchronous transceiver interface. The UART IP core is implemented in the FPGA of the PL end inside the core SOC, and appropriate buffers and control logic are added to realize autonomous asynchronous serial communication. Through the point-to-point signal interaction between the nine-way serial data transceiver in the RS422 communication circuit and the SOC processing module, the system is provided with the ability to communicate with the host computer or other control systems, realize remote monitoring, parameter setting and fault diagnosis, and enhance the flexibility and maintainability of the system.

[0035] During operation, the AC synchronous motor generates phase currents. The AD current acquisition module captures these current values ​​in real time and converts them into digital signals and sends them to the SOC processing module. The SOC processing module calculates the precise PWM control strategy based on current feedback and the preset control algorithm, and outputs 6 PWM control signals to three independent power drive modules. The digital isolator inside each power drive module converts the PWM signal into an analog signal. Then the power driver controls the corresponding three-phase bridge according to the analog signal to adjust the current and voltage of the motor, thereby achieving precise control of the motor, such as speed regulation and torque control. Throughout the process, the power conversion module ensures the stable power supply of the SOC processing module and the digital isolator, power driver and three-phase bridge in the power drive module, while the RS422 communication module provides a bridge for the system to interact with the outside world, which is convenient for monitoring and debugging.

[0036] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A three-channel intelligent motor servo drive system based on SOC, characterized in that: include: AD current acquisition module, used to convert the acquired phase current analog signal into parallel digital signal data; SOC processing module, used for calculating and processing parallel digital signal data, outputting motor control digital signals, realizing RS422 communication transceiver function, and storing motor status information and fault information; The power drive module is used to control the opening and closing of the three-phase bridge according to the motor control signal, thereby controlling the operation of the motor; The power conversion module is used to convert the control power into three power supplies, one of which is used to supply power to the SOC processing module, and the other two are used to supply power to the power drive module.

2. A three-channel intelligent motor servo drive system based on SOC according to claim 1, characterized in that: The power conversion module includes a Π-type filter, a PWM controller and a transformer. The power conversion module converts the control power supply into an isolated three-way power supply through the Π-type filter, the PWM controller and the transformer.

3. A three-channel intelligent motor servo drive system based on SOC according to claim 2, characterized in that: One of the three power supplies converted by the power conversion module acts on the SOC processing module through a four-channel regulator, and the remaining two power supplies act on the power drive module.

4. The three-channel intelligent motor servo drive system based on SOC according to claim 1 is characterized in that: The power driving module includes a digital isolator, one end of which is connected to the SOC processing module. The digital isolator receives the motor control digital signal output by the SOC processing module and outputs the motor control analog signal.

5. The three-channel intelligent motor servo drive system based on SOC according to claim 4 is characterized in that: The power drive module also includes a power driver, one end of the power controller is connected to the other end of the digital isolator, the other end of the power controller is connected to the three-phase bridge, the power driver receives an analog signal and outputs a three-phase bridge gate control signal, and the three-phase bridge gate control signal controls the opening and closing of the three-phase bridge.

6. The three-channel intelligent motor servo drive system based on SOC according to claim 1, characterized in that: The three-channel intelligent motor servo drive system also includes a power conversion module, which is used to convert the control power supply into three power supplies and act on the SOC processing module and the power drive module.

7. The three-channel intelligent motor servo drive system based on SOC according to claim 6, characterized in that: The three-channel intelligent motor servo drive system includes three power drive modules, and each of the three power drive modules is connected to an AD current sampling module.

8. The three-channel intelligent motor servo drive system based on SOC according to claim 1, characterized in that: The three-channel intelligent motor servo drive system also includes an RS422 communication module, and the RS422 communication module is connected to the SOC processing module.

9. A three-channel intelligent motor servo drive method based on SOC, characterized in that: A three-channel intelligent motor servo drive system based on SOC according to any one of claims 1 to 7, comprising the following steps: Step 1: The AD current acquisition module collects the A-phase current and the B-phase current from the motor, and converts the two phase currents into parallel digital signals and outputs them to the SOC processing module; Step 2: After the parallel digital signals are processed and calculated in the SOC processing module, the motor control digital signals are output, and the SOC processing module sends the motor control digital signals to the power drive module; Step 3: The power drive module converts the motor control digital signal into a motor control signal, and controls the operation of the motor according to the motor control signal.

10. A three-channel intelligent motor servo driving method based on SOC according to claim 9, characterized in that: The motor control digital signal output by the SOC processing module is a PWM control signal. Each channel power drive module receives 6 PWM control signals respectively to control the shutdown of the three-phase bridge.

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