Miniaturized redundant rudder controller and control method

Abstract

The application discloses a kind of miniaturization redundancy steering engine controller and control method, including dual-redundancy control unit, master-slave control signal switching unit, five-phase redundant drive unit;Dual-redundancy control unit adopts dual-MCU architecture, communication is carried out between the two through SCI, MCU and host computer are communicated through CAN and realize external communication function;The position information, current, voltage and other information of motor are sent into the analog acquisition pin of respective MCU after signal conditioning;Each MCU outputs ten-channel PWM signal, and the switching of driving signal is realized after signal switching circuit;Ten-channel PWM signal realizes the isolation of driving signal after digital isolator, and power amplifier realizes the inversion of five-phase motor drive, and forms five-phase redundant drive unit with current sensor.The application reduces the quantity, volume, weight and complexity of connection of actuator, and is suitable for high-reliability application scenarios with stringent requirements on space and weight.

Description

Technical Field

[0001] This invention belongs to the field of automatic control redundancy design technology, specifically relating to a miniaturized redundant servo controller and control method. Background Technology

[0002] As the core execution unit for high-precision motion control, servo controllers face the dual challenges of improving reliability and reducing size and weight in miniaturized equipment such as UAVs and robots. Traditional single-redundancy architectures are prone to single-point failures, leading to the development of dual-redundancy architectures. These architectures employ a master-slave hot backup mode, achieving redundancy management but suffering from reduced power density. Dual redundancy consists of two identical hardware and mechanical systems, with failure points in the servo system primarily occurring in open circuits in the motor windings and short circuits in the power circuits. Using two motors and two sets of power drive hardware increases the system's size. CN 121501024 A discloses a switching control method for a dual-redundancy servo controller, implementing switching control through three FPGA logic processing modules: FPGA_1 controls the master and backup control boards, FPGA_2 controls three master drive boards, and FPGA_3 controls three backup drive boards, avoiding the situation where a single component failure affects the overall operation. The master and backup drive control circuits share states and verify each other via dual-machine communication 422, and can detect and automatically switch when a failure occurs in one redundancy. CN 101799689 A discloses a dual-redundant servo controller, wherein the central control unit is a DSP chip digital signal processor, which is divided into two groups and input to two sets of identical power drive units consisting of a power drive chip and an H-bridge circuit respectively; the drive power supply of the two sets of power drive units and the voltage output to the servo (M) are switched by a fault switching unit controlled by the digital signal processor.

[0003] The existing system technical solutions have the following problems and shortcomings:

[0004] 1) There are risks associated with switching between redundancy modes.

[0005] The system can only switch between two states: "fully normal" and "switch to backup." The switching process involves complex fault diagnosis, logical judgment, and power on / off, resulting in a brief performance interruption. For a three-phase motor drive unit, a failure in any phase winding, power transistor, or sensor will cause the entire motor to be considered a failure, forcing the system to switch to the backup unit.

[0006] 2) Large size and weight, which is not conducive to miniaturization.

[0007] To achieve redundancy, the entire drive actuator (motor, driver, some sensors, and wiring harness) was replicated, resulting in the system's size and weight doubling. This runs counter to the urgent needs of modern aerospace, robotics, and other fields for miniaturized, lightweight, and high-power-density actuators.

[0008] 3) Common fault risk exists

[0009] Although the circuits are physically isolated, two identical three-phase motor control systems may have the same vulnerability to certain environmental stresses (such as vibrations at specific frequencies or electromagnetic interference), posing a risk of simultaneous failure and reducing the advantage of redundancy. Summary of the Invention

[0010] The purpose of this invention is to solve the problems of short-term performance interruption, poor environmental resistance, large size, heavy weight and low redundancy in dual-redundant servo systems, and to provide a miniaturized redundant servo controller and control method.

[0011] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0012] This invention discloses a miniaturized redundant servo controller, which adopts a separate design scheme of dual-redundancy control circuit and five-phase redundant drive. The dual-redundancy control unit ensures high reliability of signal processing and decision-making through the dual redundancy of the control circuit. The drive circuit adopts five-phase redundant drive in conjunction with a five-phase motor to achieve redundant drive, which physically realizes integration and miniaturization. This invention breaks through the existing dual-channel independent hardware mode, and while ensuring a higher level of reliability, it significantly reduces the size and weight of the system and reduces the complexity of the system.

[0013] Five-phase motors have stronger fault-tolerant operation capabilities. In the event of a single-phase or multi-phase fault, the system can maintain stable operation through the reconstruction of the control algorithm, which is called "phase loss redundancy" and provides smoother and more reliable fault-tolerant performance.

[0014] By adopting a highly integrated five-phase drive unit, a large number of repetitive components and interfaces such as motors, bearings, and connecting cables are reduced, greatly compressing the size and weight of the system and achieving the performance requirements of high performance, high reliability, and miniaturization.

[0015] A miniaturized redundant servo controller includes a dual-redundant control unit, a master-slave control signal switching unit, and a five-phase redundant drive unit. The dual-redundant control unit adopts a dual microcontroller unit (MCU) architecture, and the two communicate with each other through a serial communication interface (SCI). The MCU communicates with the host computer via a local area network (CAN) to achieve external communication. The position information, current, voltage, and other information of the motor are sent to the analog acquisition pins of their respective MCUs after signal conditioning. Each MCU outputs ten PWM signals, which are switched by a signal switching circuit to realize the switching of drive signals. The ten PWM signals are isolated by a digital isolator, and the power amplifier realizes the inversion of the five-phase motor drive, forming a five-phase redundant drive unit with the current sensor.

[0016] A servo control method for a miniaturized redundant servo controller includes the following steps:

[0017] 1) Upon system power-up, the dual MCUs, switching circuit, and drive circuit complete their initialization sequentially;

[0018] 2) The main control MCU is responsible for complete closed-loop control, collecting position, speed and current data from the motor sensors. The main control MCU receives CAN commands from the host computer, calculates and outputs ten PWM channels, which drive the five-phase motor after passing through the switching circuit, isolator and inverter.

[0019] The same control algorithm is run synchronously from the MCU, and the status of the main MCU and motor data are monitored in real time, but no valid PWM is output; it is only used for hot backup.

[0020] 3) SCI information exchange.

[0021] 4) During operation, the two MCUs periodically exchange self-test results and key control variables (current, speed, fault codes) through SCI to achieve cross-verification.

[0022] 5) Master-slave switching control

[0023] Main MCU fault diagnosis criteria: communication timeout, critical variable abnormality, program runaway / reset signal abnormality, etc.

[0024] The switching unit uses hardware circuitry to switch PWM signals, with an extremely short switching time, so the motor drive is unaware of the switching.

[0025] 6) The motor adopts a fault-tolerant control method (under open-circuit fault), including the following steps:

[0026] S1. Fault Detection and Location

[0027] The current sensor collects the five-phase current in real time, and the main control MCU quickly determines which phase is open by the current amplitude and phase deviation.

[0028] S2, Four-phase fault-tolerant mode switching

[0029] The algorithm instantly reconstructs the control model, cuts off the faulty phase, and switches the five-phase field-oriented control (FOC) algorithm to four-phase fault-tolerant FOC control; it recalculates the current command, voltage vector and PWM duty cycle of the healthy phase, and compensates for the missing torque component of the faulty phase.

[0030] S3, Torque Ripple Suppression

[0031] By optimizing the four-phase current phase, the torque pulsation introduced by the fault is offset, enabling the motor to quickly restore stable output after slight transient fluctuations.

[0032] Compared with existing technologies, the present invention has the following beneficial technical effects:

[0033] 1. This invention adopts a separate design of dual redundancy of control circuit and five-phase drive redundancy, which physically realizes integration and miniaturization, breaking through the existing dual-channel independent hardware mode, and reducing the size and weight of the system while ensuring higher reliability.

[0034] 2. This invention changes the drive core from two sets of three-phase motor drives in the existing technology to one set of five-phase motor drives, which is a fundamental change in the drive method. Compared with the existing three-phase system mode of "failure of one phase leads to failure" and the existing dual-redundancy mode of needing to switch to the backup motor, it provides smoother and more reliable fault-tolerant performance.

[0035] 3. A highly integrated five-phase drive unit replaces two independent three-phase drive units, directly reducing a large number of repetitive components and interfaces such as motors, bearings, and connecting cables, greatly compressing the system's size and weight, and perfectly meeting the urgent needs of aerospace, high-end equipment and other fields for high performance, high reliability and miniaturization. Attached Figure Description

[0036] Figure 1 This is a block diagram illustrating the principle of a miniaturized redundant servo controller according to an embodiment of the present invention.

[0037] Figure 2 This is a schematic diagram of a dual-redundant control unit in an embodiment of a miniaturized redundant servo controller of the present invention.

[0038] Figure 3 This is a schematic diagram of the master-slave control signal switching unit in an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of a five-phase redundant drive unit in an embodiment of the present invention.

[0040] Figure 5 This is a block diagram illustrating the control principle of a miniaturized redundant servo controller according to the present invention. Detailed Implementation

[0041] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] like Figure 1 As shown, this embodiment provides a miniaturized redundant servo controller and control method. The redundant servo controller includes a dual-redundant control unit, a master-slave control signal switching unit, and a five-phase redundant drive unit. The dual-redundant control unit adopts a dual microcontroller unit (MCU) architecture, and the two communicate with each other through a serial communication interface (SCI). The MCU communicates with the host computer through a local area network (CAN) to realize external communication. The position information, current, voltage, and other information of the motor are sent to the analog acquisition pins of their respective MCUs after signal conditioning. Each MCU outputs ten PWM signals, which are switched by a signal switching circuit to realize the switching of drive signals. The ten PWM signals are isolated by a digital isolator. The power amplifier realizes the inversion of the five-phase motor drive and forms a five-phase redundant drive unit with the current sensor.

[0043] like Figure 2 As shown, the dual-redundant control unit adopts a "master-slave" dual-MCU control architecture. The master and slave MCUs use the same high-performance digital signal processor, such as ARM or DSP. The master and slave MCUs are physically completely independent, running the same control algorithms, including position loop, speed loop, current loop algorithms, and fault diagnosis algorithms. The master and slave MCUs interact bidirectionally via a serial communication interface (SCI) to exchange system status, self-test results, and control commands. Mutual monitoring ensures that a fault in one MCU can be detected promptly by the other. Both MCUs connect to a host computer (such as a flight control computer) via independent Controller Area Network (CAN) bus interfaces to receive control surface position commands and report controller status. The dual CAN channels constitute a communication redundancy design. The position signal output from the five-phase motor's resolver is fed back to each MCU for position information processing via a decoding circuit. The phase current signal of each phase, collected by current sensors mounted on each phase drive arm, is processed by a signal voltage conditioning circuit and simultaneously sent to the ADC input pin of each MCU. The two MCUs have completely independent and identical sensor information input paths.

[0044] like Figure 3As shown, the master-slave control signal switching unit is responsible for safe switching between the ten PWM signals output by the dual-redundant control unit. The master and slave MCUs each independently generate ten PWM signals according to the control algorithm to drive a five-phase full-bridge inverter. Each phase requires two complementary signals from the upper and lower bridge arms. The switching logic circuit uses multiple relays for signal selection. By default, the system uses the MCU as the master controller, and its PWM signals are allowed to pass. If a fault is detected in the master MCU or its peripheral circuits, the system will seamlessly switch to the PWM signals output by the slave MCU within several PWM cycles. The switching process does not require shutting down the power supply, achieving "hot switching." The ten PWM signals output from the switching circuit are then sent to a digital isolator. The isolator completely isolates the low-voltage control signals from the high-voltage drive circuit electrically, preventing interference or faults on the high-voltage side from damaging the low-voltage control circuit.

[0045] like Figure 4 As shown, the five-phase redundant drive unit adopts five-phase redundant drive and is responsible for converting ten PWM signals into power electricity for the five-phase motor. This part is a five-phase full-bridge inverter circuit, which consists of ten high-power switching transistors (such as MOSFETs or IGBTs) and their gate drive chips, receiving PWM signals from the digital isolator; the inverter converts the DC bus voltage (according to the modulation of the PWM signal) into a five-phase sinusoidal voltage with adjustable amplitude, frequency and phase, driving the five-phase permanent magnet synchronous motor to run.

[0046] like Figure 5 As shown, a servo control method for a miniaturized redundant servo controller includes the following steps:

[0047] 1) Upon system power-up, the dual MCUs, switching circuit, and drive circuit complete their initialization sequentially;

[0048] 2) The main control MCU is responsible for complete closed-loop control, collecting position, speed and current data from the motor sensors. The main control MCU receives CAN commands from the host computer, calculates and outputs ten PWM channels, which drive the five-phase motor after passing through the switching circuit, isolator and inverter.

[0049] The same control algorithm is run synchronously from the MCU, and the status of the main MCU and motor data are monitored in real time, but no valid PWM is output; it is only used for hot backup.

[0050] 3) SCI information exchange.

[0051] 4) During operation, the two MCUs periodically exchange self-test results and key control variables (current, speed, fault codes) through SCI to achieve cross-verification.

[0052] 5) Master-slave switching control

[0053] Main MCU fault diagnosis criteria: communication timeout, critical variable abnormality, program runaway / reset signal abnormality, etc.

[0054] The switching unit uses hardware circuitry to switch PWM signals, with an extremely short switching time, so the motor drive is unaware of the switching.

[0055] 6) The motor adopts a fault-tolerant control method (under open-circuit fault), including the following steps:

[0056] S1. Fault Detection and Location

[0057] The current sensor collects the five-phase current in real time, and the main control MCU quickly determines which phase is open by the current amplitude and phase deviation.

[0058] S2, Four-phase fault-tolerant mode switching

[0059] The algorithm instantly reconstructs the control model, cuts off the faulty phase, and switches the five-phase FOC algorithm to four-phase fault-tolerant FOC control; it recalculates the current command, voltage vector and PWM duty cycle of the healthy phase, and compensates for the missing torque component of the faulty phase.

[0060] S3, Torque Ripple Suppression

[0061] By optimizing the four-phase current phase, the torque pulsation introduced by the fault is offset, enabling the motor to quickly restore stable output after slight transient fluctuations.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A miniaturized redundant servo controller, employing a separate design of dual-redundant control circuitry and five-phase redundant drive, characterized in that: Includes a dual-redundant control unit, a master-slave control signal switching unit, and a five-phase redundant drive unit; The dual-redundancy control unit ensures high reliability of signal processing and decision-making through dual redundancy in the control circuit. The master-slave control signal switching unit is responsible for safely switching between the ten PWM signals output by the dual-redundant control unit; The five-phase redundant drive unit adopts five-phase redundant drive and is responsible for converting ten PWM signals into power electricity for the five-phase motor to achieve redundant drive, and physically realizes integration and miniaturization.

2. The miniaturized redundant servo controller according to claim 1, characterized in that: When a single-phase or multi-phase fault occurs in a five-phase motor, the system maintains stable operation through the reconstruction of the control algorithm, which is called "phase loss redundancy" and provides smooth and reliable fault tolerance performance.

3. The miniaturized redundant servo controller according to claim 1, characterized in that: The dual-redundant control unit adopts a dual-microcontroller architecture. The two microcontrollers communicate with each other through a serial communication interface, and the microcontrollers communicate with the host computer through a local area network. The position, current and voltage information of the motor are sent to the analog acquisition pins of their respective microcontrollers after signal conditioning.

4. A miniaturized redundant servo controller according to claim 1 or 3, characterized in that: Each microcontroller outputs ten PWM signals, which are switched by a signal switching circuit to achieve the switching of drive signals. The ten PWM signals are isolated by a digital isolator, and the power amplifier realizes the inversion of the five-phase motor drive. Together with the current sensor, they form a five-phase redundant drive unit.

5. The miniaturized redundant servo controller according to claim 3, characterized in that: The dual microcontroller unit includes a master microcontroller unit and a slave microcontroller unit. The master and slave microcontroller units run the same control algorithms, including position loop, speed loop, current loop algorithms, and fault diagnosis algorithms. The master and slave microcontroller units interact bidirectionally, exchanging system status, self-test results, and control commands.

6. A servo control method using a miniaturized redundant servo controller as described in any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Upon system power-up, the dual microcontroller unit, switching circuit, and drive circuit sequentially complete initialization; 2) The main control microcontroller unit is responsible for complete closed-loop control, collecting position, speed and current data from the motor sensors. The main control microcontroller unit receives instructions from the host computer's local area network, calculates and outputs ten PWM channels, which drive the five-phase motor after passing through the switching circuit, isolator and inverter. The same control algorithm is run synchronously from the microcontroller unit, and the status of the main microcontroller unit and motor data are monitored in real time, but no valid PWM is output; it is only used for hot backup. 3) Serial communication interface information exchange; 4) During operation, the dual micro-control units periodically exchange self-test results and key control current, speed, and fault code variables through a serial communication interface to achieve cross-verification; 5) Master-slave switching control; Fault determination criteria for the main microcontroller unit: communication timeout, abnormal critical variables, and abnormal program runaway / reset signal; The switching unit uses hardware circuitry to switch PWM signals, with an extremely short switching time, so the motor drive is unaware of the switching. 6) In the event of an open circuit fault, the motor adopts a fault-tolerant control method.

7. The servo control method of the miniaturized redundant servo controller according to claim 6, characterized in that, The fault-tolerant control method used in the motor includes the following steps: S1. Fault detection and location; The current sensor collects the five-phase current in real time, and the main control microcontroller unit quickly determines which phase is open by the current amplitude and phase deviation. S2, Four-phase fault-tolerant mode switching; The algorithm instantly reconstructs the control model, cuts off the faulty phase, and switches the five-phase field-oriented control algorithm to a four-phase fault-tolerant field-oriented control algorithm; it recalculates the current command, voltage vector and PWM duty cycle of the healthy phase, and compensates for the missing torque component of the faulty phase. S3, Torque ripple suppression; By optimizing the four-phase current phase, the torque pulsation introduced by the fault is offset, enabling the motor to quickly restore stable output after slight transient fluctuations.

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