A dual shaft contra-rotating motor control system and method for an underwater unmanned vehicle

Abstract

The application discloses a kind of dual-shaft counter-rotating motor control system and method for underwater unmanned vehicle, it is related to underwater unmanned vehicle propulsion technical field.The motor body and motor controller are included, the motor body includes motor and speed reducer, motor single-shaft output is to speed reducer, realize double rotation output by speed reducer, motor controller includes control panel, power amplifier board, intelligent power module and filter capacitor, control panel includes DSP digital signal processing device, CPLD programmable logic device, CAN communication circuit, rotary encoder and other modules, the program of control motor initialization, power-on self-test, data acquisition and calculation, periodic self-checking is installed in DSP digital signal processing device, the program of interactive acquisition motor drive fault and position, speed, phase current data is installed in CPLD programmable logic device, and control signal is output, the control algorithm of motor controller includes with SVPWM algorithm combination hardware acceleration, position ring-speed ring-current ring three-ring nested control architecture is adopted, high-precision control is realized by closed-loop feedback, and PWM frequency is adjusted to 10K and dead time.

Description

Technical Field

[0001] This invention relates to the field of underwater unmanned vehicle technology, and in particular to a dual-axis counter-rotating motor control system and method for underwater unmanned vehicles. Background Technology

[0002] This invention relates to a motor controller for a dual-axis counter-rotating brushless DC motor used in underwater unmanned vehicles (UUVs). As core equipment for marine exploration and military applications, the performance of the UUV's propulsion system directly determines its maneuverability, endurance, and mission reliability. To suppress the roll torque of UUVs, they require a dual-axis counter-rotating motor to achieve precise control of propulsion and torque. Existing research largely focuses on single-axis propulsion optimization or compensation through mechanical structures. Single-axis propulsion systems use traditional brushless DC motor controllers. There is a lack of controllers specifically designed for UUV dual-axis counter-rotating motors on the market. Existing dual-axis counter-rotating controllers suffer from asynchronous control of the inner and outer shaft speeds and motor efficiency of only 75%-80%. Summary of the Invention

[0003] To address the aforementioned technical bottlenecks, the purpose of this invention is to provide a novel dual-axis counter-rotating motor control system and method for underwater unmanned vehicles (UUVs). The controller is specifically designed for the dual-axis counter-rotating brushless DC motor of UUVs, achieving high-precision synchronous control, improving navigation stability, enhancing motor energy efficiency to over 85%, and extending the UUV's range.

[0004] The technical solution proposed in this invention is implemented as follows: A dual-axis counter-rotating motor control system for an underwater unmanned vehicle includes a motor body and a motor controller. The motor body includes a motor and a reducer. The motor is a permanent magnet synchronous brushless DC motor, and position feedback is achieved using a rotary transformer. The motor outputs from one axis to the reducer, which enables dual-rotating output. The reducer is a planetary reducer. The motor controller includes a control board, a power amplifier board, an IPM intelligent power module, a filter capacitor, a port for receiving resolver signals from the rotary transformer, and a port for communicating with a host computer. The signal input / output terminals of the control board are connected to the signal input / output terminals of the power amplifier board, which are also connected to the signal input / output terminals of the IPM intelligent power module. One end of the filter capacitor is connected to the operating power supply, and the other end is connected to the IPM intelligent power module. The control board includes a DSP digital signal processing device, a CPLD programmable logic device, a CAN communication module, a rotary encoder, a power supply circuit, a data storage circuit, a protection circuit, and an external interface. The CPLD programmable logic device is connected to the DSP digital signal processing device, the data storage circuit, the rotary encoder, and the protection circuit. The rotary encoder is connected to the rotary transformer in the motor body, and the DSP digital signal processing device is connected to the CAN communication module. The power amplifier board includes a power conversion circuit, an IPM driver, an FO fault output, and a current detection module. The DSP digital signal processing device on the control board interacts with the host computer via a CAN communication module; it interacts with the EEPROM memory via an SPI communication interface; it controls multiple I / O operations to acquire data and output signals; and it interacts with a CPLD programmable logic device to obtain drive fault, position, speed, and phase current data, and outputs control signals. The CPLD programmable logic device implements the timing and logic control of the controller, as well as the acquisition and calculation of phase current and position data.

[0005] The IPM intelligent power module adopts a single-chip integrated intelligent module. The DSP digital signal processing device is a microprocessor chip with programs for controlling motor initialization, power-on self-test, data acquisition and calculation, and periodic self-test. The CPLD programmable logic device has a built-in program for interactively acquiring motor drive fault and position, speed, and phase current data, and outputs control signals.

[0006] The input terminal of the current detection module of the power amplifier board is connected to the output terminal of the IPM intelligent power module to receive the three-phase drive currents U, V, and W. The output terminal of the current detection module is connected to the three-phase motor M. The three-phase motor M receives the three-phase current output by the current detection module and converts electrical energy into mechanical energy to achieve rotational motion.

[0007] The power amplifier board's current detection module includes bus current acquisition and phase current acquisition. The phase current acquisition uses a surface-mount Hall current sensor, with the Hall chip model being HCS724A-KMA. The control board's rotary encoder includes a resolver / digital converter circuit. This converter circuit converts the analog modulation signal output from the resolver into a digital signal corresponding to the mechanical angle and speed of the motor rotor. The resolver / digital converter model is AD2S1210CSTZ.

[0008] The protection circuit of the control board includes temperature protection and phase current protection. The C-phase current protection circuit consists of multiple operational amplifiers, diodes, transistors, comparator reference circuits, resistors, and capacitors. One end of the two input terminals of operational amplifier U15B is connected to the output terminal of the previous stage operational amplifier U14B, and the other end is connected to the voltage threshold output terminal of the comparator reference circuit. The output terminal of operational amplifier U15B is connected to transistor Q6. The comparison result is level-shifted and power-amplified by transistor Q6, and finally outputs an IC-Alert overcurrent alarm signal. The A-phase current protection circuit is constructed in the same way as the C-phase current protection circuit.

[0009] A method for controlling a dual-axis counter-rotating motor for an underwater unmanned vehicle, wherein the control steps of the motor controller include: Step 1: Power-on initialization: The motor system enters the initialization process immediately after power-on, at which point all system control parameters are called. Step 2: Initialization complete, begin data acquisition and calculation; Step 3: Upon power-up, the built-in self-test bit automatically performs a round of hardware self-tests to quickly identify critical hardware faults; Step 4: CAN communication. After receiving the CAN communication command, control the system status. Step 5: Periodic built-in self-test BIT, which automatically performs hardware self-test mechanism at fixed time intervals, complements the built-in power-on self-test, and is mainly used to detect dynamic faults, performance drift and hidden failures that occur during system operation. Step 6: Execute system control functions, including circuit vector control, speed closed-loop control, and PWM wave output.

[0010] The built-in power-on self-test bit includes checks for reference voltage, resolver, CPU, undervoltage, overcurrent, overheating, and CAN communication. The periodic built-in self-test bit includes checks for abnormalities in the controller, voltage, current, resolver, drive, and temperature, and calls the control function every 167 microseconds to perform real-time motor control.

[0011] The algorithms used in steps 1 to 6 include: using the SVPWM algorithm combined with hardware acceleration, employing a three-loop nested control architecture of position loop, speed loop, and current loop, achieving high-precision control through closed-loop feedback, adjusting the PWM frequency to 10KHz and the dead time; ensuring that the PWM frequency is much higher than the load's time constant to avoid current discontinuity or control instability; during power-on initialization, acquiring the initial binary values ​​of the U and W phase currents and correcting them in the phase currents involved in the calculation; filtering the current and speed to ensure that sampling interference does not affect the real-time control of the motor; and adding synchronous data acquisition: PID adjustment is completed through the host computer.

[0012] This invention proposes a dual-axis counter-rotating motor control system and method for underwater unmanned vehicles (UUVs). It innovatively adopts an integrated design of "motor + reducer" and specifically designs a control system and method for the dual-axis counter-rotating motor of UUVs. The controller uses advanced control algorithms to solve the long-standing problem of efficiency versus accuracy in UUV propulsion systems, restoring motor efficiency to over 85%, extending the UUV's range, and providing a reliable power solution for applications such as deep-sea exploration and military reconnaissance. Attached Figure Description

[0013] Figure 1 : Working principle diagram of the motor system; Figure 2 Schematic diagram of a dual-rotation motor + reducer; Figure 3 Overall structure diagram of the propulsion system; Figure 4 Hardware block diagram of the controller; Figure 5 Schematic diagram of phase current acquisition circuit; Figure 6 Phase current protection circuit diagram; Figure 7 Circuit diagram for motor position and speed acquisition; Figure 8 : Controller control content and working steps flowchart; Figure 9 : DSP digital signal processing device workflow diagram; Figure 10 Flowchart of SVPWM application in motor controller.

[0014] The technical solutions and advantages of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] 1. The UUV motor body innovatively adopts an integrated design of "motor + reducer": This solution innovatively adopts an integrated "motor + reducer" design for the UUV motor body. The motor outputs to the reducer via a single shaft, achieving dual-rotation output through the reducer. Figure 2 As shown. Permanent magnet synchronous motors have higher efficiency, power density, and a wider speed range. Therefore, this product uses a permanent magnet synchronous brushless DC motor, and its position feedback uses a wound-rotor brushless rotary transformer from Shanghai Xinrui Drive Technology Co., Ltd., model J52XFW001.

[0016] This solution achieves forward and reverse rotation through a planetary reducer. It can increase the motor speed and thus improve motor efficiency by using the planetary reducer, and it can also use the planetary reducer itself to achieve efficient forward and reverse rotation, suppressing the speed difference between the inner and outer shafts to <3 rpm, thereby improving navigation stability.

[0017] 2. UUV Controller Hardware Design 1) A controller specifically designed for UUV dual-axis counter-rotating motors. This controller is mainly used in UUV underwater electric propulsion systems. It can realize closed-loop control of speed and phase current, ensure small changes in motor torque / current, good motor operation stability, and significantly improve the high-efficiency operating range of the motor, thereby enhancing motor energy efficiency.

[0018] The controller consists of a hardware system and controller software. The hardware system comprises four parts: a control board (j), a power amplifier board (k), an intelligent power module (IPM) (l), and filter capacitors (m). The software consists of DSP software programs and CPLD software programs. The overall structure of the propulsion system is as follows: Figure 3 .

[0019] The controller includes control circuitry (including a DC / DC power module, DSP digital signal processing, CPLD programmable logic device, communication control interface, digital opto-isolated drive, and other peripheral circuits), an IPM (Integrated Power Module), position signal detection and acquisition circuitry, and protection circuitry. The hardware composition of this propulsion motor unit, such as... Figure 4 As shown.

[0020] ① The DSP interacts with the host computer via CAN communication; it interacts with the EEPROM memory via SPI communication; it controls multiple I / Os to acquire data and output signals; and it interacts with the CPLD to obtain data such as drive faults, position, speed, and phase current, and outputs control signals. The CPLD circuit mainly implements the timing and logic control of the controller, and the acquisition and calculation of phase current and position data, such as... Figure 4 As shown.

[0021] ② The control board is based on the domestically produced DSP CMDSPF2812, and also includes CPLD circuits, communication circuits, resolver signal acquisition, voltage and current acquisition and processing, control board temperature acquisition, power supply circuits, data storage modules, etc. The control board has CAN communication capabilities, using a TJA1050T CAN bus transceiver, which can provide differential transmission and reception capabilities for CAN controllers with signal transmission rates up to 1Mbps. It can operate in harsh environments, and the chip bus pins have ±12kV ESD protection, supporting bus voltages from -58V to 58V. It also has built-in over-temperature protection and short-circuit protection circuits.

[0022] ③ The resolver signal acquisition uses the AD2S1210CSTZ for A / D conversion. This is a 10-bit to 16-bit resolution resolver-to-digital converter with an integrated on-chip programmable sine wave oscillator to provide sine wave excitation for the resolver. The sampling rate can reach 20kHz, and it can simultaneously acquire motor position and speed. The schematic diagram for resolver acquisition of motor position and speed is shown below. Figure 7 .

[0023] ④ Current Acquisition: Current acquisition uses a surface-mount Hall effect chip, such as... Figure 5 As shown, its high sensitivity, anti-interference capability, and miniaturization make it ideal for precision current monitoring applications such as motor control. By monitoring current in real time, the PWM duty cycle and commutation timing are optimized, reducing copper and iron losses and improving motor efficiency. Real-time monitoring of the bus current allows the system to promptly detect power fluctuations and load changes, providing crucial information for overcurrent and undervoltage protection mechanisms, effectively preventing equipment damage. Simultaneously, synchronous acquisition of U and W phase currents not only optimizes the accuracy of PWM waveform generation but also enables millisecond-level response to hardware faults by rapidly identifying current anomalies (such as overcurrent and short circuits), significantly improving the dynamic performance and reliability of motor control.

[0024] ⑤ Data storage uses EEPROM storage chips to store key parameters during navigation, forming a complete historical data chain.

[0025] ⑥ Protection Circuit: Overheat protection monitors motor temperature in real time; undervoltage protection detects grid voltage fluctuations and, when the voltage falls below a set ratio, determines whether to cut off the power supply after a delay to prevent abnormal motor shutdown due to insufficient voltage; overcurrent protection activates rapidly when the current exceeds the limit; resolver fault protection estimates the speed based on historical data and triggers a safety shutdown mechanism when the sensor fails, avoiding the risk of high-speed operation; CPU fault protection ensures stable operation of the main control chip through hardware detection (such as phase-locked loop and watchdog timer) and software verification (dual-core comparison), and immediately enters a safe mode in case of an anomaly. These protection mechanisms work together to provide comprehensive fault protection for the motor, significantly improving system reliability. Current protection circuits, such as... Figure 6 As shown.

[0026] 2) The power amplifier board includes modules such as power conversion circuit, IPM driver, FO fault output, and voltage and current acquisition. Bus voltage acquisition controls the maximum output voltage limit of the motor.

[0027] 3. Implementation of the dual-axis counter-rotating motor control method for underwater unmanned vehicles: 1) The controller's control content and operating steps are as follows: Figure 8 As shown, it is mainly divided into an initialization module, a power-on self-test module, a data acquisition and calculation module, and a periodic self-test module, which includes power-on detection, periodic detection, data acquisition, power-on initialization, and control functions.

[0028] The power-on self-test checks the reference voltage, resolver, CPU, undervoltage, overcurrent, and overheating CAN communication; the periodic detection includes checking the controller, voltage, current, resolver, drive, temperature, etc. for any abnormalities, and calls the control function every 167 microseconds to perform real-time control of the motor.

[0029] 2) Algorithm optimization to improve motor efficiency. The SVPWM algorithm is combined with hardware acceleration, and a three-loop nested control architecture of position loop-speed loop-current loop is adopted. High-precision control is achieved through closed-loop feedback, and the PWM frequency and dead time are adjusted to 10K.

[0030] ① Determine the load time constant: the ratio of phase inductance L to phase resistance R. Typically, the PWM frequency needs to be much greater than 10 times 1 / (L / R). For motors, the PWM frequency must be much higher than the load time constant to avoid intermittent current or unstable control. The existing motor has a rated power of 9kW, a power operating voltage of 190VDC~287VDC, phase resistance: 0.357Ω, and phase inductance: 445μH; L d : 481μH; L q : 493μH.

[0031] τ = L / R = (445×10) -6 ) / 0.357≈0.0012465; 10 / τ = 10 / 0.0012465 = 8020Hz; Therefore, the PWM frequency must not be lower than 8KHz, and the PWM frequency is selected as 10KHz.

[0032] ② Apply the SVPWM algorithm to the UUV motor controller. The specific process of applying SVPWM to the controller is as follows: Figure 10 As shown. Three-phase current I u I v I w After being transformed by CLARK into I α and I β Then, through PARK, it is transformed into real-time feedback I. dfdb I qfdb The real-time I obtained dfdb I qfdb The feedback value is obtained through PID control. dref I qref After obtaining the given value, obtain U d and U q After a given value is given, FPARK changes to U. α and U β To obtain the given U α and U β Then, in the SVPWM module, sector determination → calculation of action time → determination of switching point (selecting seven-segment insertion zero vector).

[0033] ③ To ensure the accuracy of the phase currents involved in the control, the initial binary values ​​of the U and Q phase currents are collected during the controller power-on initialization and corrected in the phase currents involved in the calculation.

[0034] Acquire the initial binary values ​​of the U and W phase currents: Ia.pianz = Ia.CyData; / *U-phase current polarization * / ; Ic.pianz = Ic.CyData; / *W-phase current polarization* / ; The phase currents involved in the calculation are corrected as follows: Ia.ThData =0- _IQtoF(_IQmpy(_IQ((int)(Ia.CyData -; Ia.pianz)) ,_IQ(I_AD_XS_4))); / *U-phase current processing* / ; Ic.ThData =0- _IQtoF(_IQmpy(_IQ((int)(Ic.CyData -; Ic.pianz)) ,_IQ(I_AD_XS_4))); / *W-phase current processing* / ; In addition, the current and speed are filtered to ensure that sampling interference does not affect the real-time control of the motor.

[0035] ④ Increased Data Synchronization Acquisition: While running the control algorithm, the motor controller transmits the actual intermediate variables Idfdb, Iqref, Iqfdb, and the actual instantaneous variable W-phase current IC generated during algorithm execution to the host computer via the CAN bus. A three-loop nested control architecture (position loop, speed loop, and current loop) is adopted, achieving high-precision control through closed-loop feedback, with PID adjustment completed by the host computer.

Claims

1. A dual-axis counter-rotating motor control system for an underwater unmanned vehicle, comprising a motor body and a motor controller, characterized in that: The motor body includes a motor and a reducer. The motor outputs a single shaft to the reducer, which enables dual rotary output. Position feedback uses a rotary transformer. The motor controller includes a control board, a power amplifier board, an IPM intelligent power module, a filter capacitor, and a receiving rotary transformer. The rotary transformer provides the port for the resolver signal and a port for communication with the host computer. The signal input / output terminals of the control board are connected to the signal input / output terminals of the power amplifier board, which are also connected to the signal input / output terminals of the IPM intelligent power module. One end of the filter capacitor is connected to the power supply, and the other end is connected to the IPM intelligent power module. The control board includes a DSP digital signal processing device, a CPLD programmable logic device, a CAN communication module, a rotary encoder, a power supply circuit, a data storage circuit, a protection circuit, and external interfaces. The CPLD programmable logic device is connected to the DSP digital signal processing device, data storage circuit, rotary encoder and protection circuit. The rotary encoder is connected to the rotary transformer in the motor body. The DSP digital signal processing device is connected to the CAN communication module. The power amplifier board includes a power conversion circuit, an IPM driver, an FO fault output, and a current detection module.

2. The dual-axis counter-rotating motor control system for underwater unmanned vehicles according to claim 1, characterized in that: The DSP digital signal processing device of the control board interacts with the host computer through the CAN communication module; it interacts with the EEPROM memory through the SPI communication interface; it controls multiple I / O to acquire data and output signals; it interacts with the CPLD programmable logic device to obtain drive fault and position, speed and phase current data, and outputs control signals. The CPLD programmable logic device realizes the timing and logic control of the controller, and the acquisition and calculation of phase current and position data.

3. The dual-axis counter-rotating motor control system for underwater unmanned vehicles according to claim 1, characterized in that: The IPM intelligent power module adopts a single-chip integrated intelligent module. The DSP digital signal processing device adopts a microprocessor chip with a program for controlling motor initialization, power-on self-test, data acquisition and calculation, and periodic self-test. The CPLD programmable logic device has a built-in program for interactively acquiring motor drive fault and position, speed, and phase current data, and outputs control signals.

4. The dual-axis counter-rotating motor control system for underwater unmanned vehicles according to claim 1, characterized in that: The input terminal of the current detection module of the power amplifier board is connected to the output terminal of the IPM intelligent power module to receive the three-phase drive currents U, V, and W. The output terminal of the current detection module is connected to the three-phase motor M. The three-phase motor M receives the three-phase current output by the current detection module and converts electrical energy into mechanical energy to achieve rotational motion. The current detection module of the power amplifier board includes bus current acquisition and phase current acquisition. The phase current acquisition adopts a surface-mount Hall current sensor, and the Hall chip model is HCS724A-KMA.

5. The dual-axis counter-rotating motor control system for underwater unmanned vehicles according to claim 1, characterized in that: The rotary encoder of the control board includes a resolver / digital converter circuit, which converts the analog modulation signal output by the resolver into a digital signal corresponding to the mechanical angle and speed of the motor rotor. The resolver / digital converter is model AD2S1210CSTZ. The reducer is a planetary reducer. The motor is a permanent magnet synchronous brushless DC motor.

6. The dual-axis counter-rotating motor control system for underwater unmanned vehicles according to claim 1, characterized in that: The protection circuit of the control board includes temperature protection and phase current protection. The C-phase current protection circuit consists of multiple operational amplifiers, diodes, transistors, comparator reference circuits, resistors, and capacitors. One end of the two input terminals of operational amplifier U15B is connected to the output terminal of the previous stage operational amplifier U14B, and the other end is connected to the voltage threshold output terminal of the comparator reference circuit. The output terminal of operational amplifier U15B is connected to transistor Q6. The comparison result is level-shifted and power-amplified by transistor Q6, and finally outputs an IC-Alert overcurrent alarm signal. The A-phase current protection circuit is constructed in the same way as the C-phase current protection circuit.

7. A method for controlling a dual-axis counter-rotating motor for an underwater unmanned vehicle, characterized in that: The control steps of the motor controller include: Step 1: Power-on initialization: The motor system enters the initialization process immediately after power-on, at which point all system control parameters are called. Step 2: Initialization complete, begin data acquisition and calculation; Step 3: Upon power-up, the built-in self-test bit automatically performs a round of hardware self-tests to quickly identify critical hardware faults; Step 4: CAN communication. After receiving the CAN communication command, control the system status. Step 5: Periodic built-in self-test BIT, which automatically performs hardware self-test mechanism at fixed time intervals, complements the built-in power-on self-test, and is mainly used to detect dynamic faults, performance drift and hidden failures that occur during system operation. Step 6: Execute system control functions, including circuit vector control, speed closed-loop control, and PWM wave output.

8. The dual-axis counter-rotating motor control method for underwater unmanned vehicles according to claim 7, characterized in that: The power-on built-in self-test bit in step 3 includes detection of reference voltage, rotary transformer, CPU, undervoltage, overcurrent, overheating, and CAN communication.

9. The dual-axis counter-rotating motor control method for underwater unmanned vehicles according to claim 7, characterized in that: The periodic built-in self-test BIT in step 5 includes: checking for abnormalities in the controller, voltage, current, resolver, drive, and temperature, and calling the control function every 167 microseconds to perform real-time control of the motor.

10. The dual-axis counter-rotating motor control method for underwater unmanned vehicles according to claim 7, characterized in that: The algorithms used in steps 1 to 6 include: The SVPWM algorithm is combined with hardware acceleration, and a three-loop nested control architecture of position loop-velocity loop-current loop is adopted. High-precision control is achieved through closed-loop feedback, and the PWM frequency is adjusted to 10K and the dead time is adjusted. Ensure that the PWM frequency is much higher than the load's time constant to avoid intermittent current or unstable control. During power-on initialization, the initial binary values ​​of the U and W phase currents are acquired and corrected in the phase currents involved in the calculation. The current and speed are filtered to ensure that sampling interference does not affect the real-time control of the motor. Add synchronous data acquisition: PID adjustment is completed via a host computer.

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