Underwater unmanned vehicle driving circuit and dual-mode power conversion method

Abstract

The invention belongs to the technical field of underwater unmanned vehicle control, and particularly relates to an underwater unmanned vehicle driving circuit and a dual-mode power conversion method, the underwater unmanned vehicle driving circuit comprises a power conversion unit, a hysteresis comparison unit and a PWM control unit, during specific implementation, a UUV (unmanned underwater vehicle) is driven in a short-time pursuit mode in a multi-tube parallel driving mode, and the dual-mode power conversion of the UUV is realized. A high-power motor driving function is achieved, rapid acceleration and high-speed advancing functions of the UUV are completed, in a long-time cruise mode, a single-tube driving mode is used, the driving function is completed, conduction loss generated when a plurality of power devices are turned on and off at the same time is reduced, loss of a driver in the long-time cruise mode is reduced, electric energy consumption is reduced, driving efficiency is improved, and the service life of the UUV is prolonged. The battery (power supply) energy is saved, the cruising time is prolonged, and energy-saving control is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater unmanned vehicle control, and in particular relates to an underwater unmanned vehicle driving circuit and a dual-mode power conversion method. Background Art

[0002] As an advanced underwater operation equipment, electric underwater unmanned vehicle (UUV) plays an important role in many fields such as marine patrol, reconnaissance and exploration. Its power system is the core part to realize various functions, mainly composed of batteries (power supply), drivers, motors and propellers. In this system, the driver plays a key role in power conversion and power regulation. It converts the DC voltage provided by the power supply into an AC voltage suitable for driving the motor to rotate, and then accurately controls the speed and torque of the motor, and finally drives the propeller to rotate, providing the necessary power source for the UUV to move forward or backward underwater.

[0003] UUVs usually operate in different working modes in different mission scenarios, which can be mainly divided into cruise mode and pursuit mode. In cruise mode, UUVs need to maintain a stable and low speed for a long time. At this time, the power motor runs at a fixed speed. Its main task is to overcome the resistance of the water flow and continue to do work. Correspondingly, the motor output power is at a low level. When the UUV performs specific tasks, such as finding a target and needing to approach quickly or avoid the target's escape, it will switch to pursuit mode. In this mode, the UUV needs to quickly increase to the maximum speed in a short period of time. This process is accompanied by a significant increase in the acceleration of the system, which causes the torque of the power motor to increase sharply. As the speed continues to increase, the motor must achieve high power output in a short period of time to meet the needs of rapid maneuvers.

[0004] Endurance is an extremely critical indicator for UUVs, which directly determines whether the UUV can successfully complete underwater missions and the effectiveness of the missions. In order to improve endurance, traditional methods often focus on increasing the volume of portable batteries (power sources) to increase the battery's storage energy. However, this method has obvious disadvantages. As the volume of the power source increases, the weight of the UUV will also increase accordingly, which will lead to a significant increase in consumption during the movement of the UUV, and in turn reduce the operating efficiency of the entire system. Therefore, starting from the drive system, improving the drive efficiency of the UUV is of vital importance to increasing its endurance.

[0005] In terms of driver design, the solution of the drive unit has a decisive influence on the size of its output power. For high-power motor drivers, their three-phase full-bridge drive units usually adopt a multi-tube parallel design. Specifically, the single-tube solution uses a single power electronic device (such as MOSFET, IGBT, SiC, etc.) to build an upper bridge arm or lower bridge arm in the module, while the multi-tube parallel solution uses two or more power electronic devices and peripheral circuits to form the upper bridge arm or lower bridge arm in the module. This multi-tube parallel solution has many advantages. It can effectively meet the output requirements of large currents, thereby significantly increasing the output current capacity of the driver. At the same time, through reasonable layout design, the position of the power device can be flexibly arranged, thereby increasing the heat dissipation area of ​​the power device and achieving uniform distribution of the heat source, which is conducive to improving the overall performance and stability of the driver.

[0006] However, there are also some urgent problems to be solved in the current drive technology. The loss of the drive mainly comes from the power electronic devices in the drive unit, which can be roughly divided into switching loss and conduction loss. Among them, the switching loss is caused by each opening and closing operation of the power electronic devices in the high-frequency (10kHZ - 20kHz) working mode. At present, most high-power drives lack an effective management mechanism for the use of power electronic devices in the two different working modes of cruising and pursuit when using multi-tube parallel schemes. This leads to the fact that in the actual operation process, all power electronic devices are in the same working state regardless of the working mode, resulting in a large amount of energy waste, which seriously affects the endurance of UUV. In addition, some solutions use the core processor (CPU) control method, that is, to control the on and off of some power electronic devices through embedded software. Although this method can theoretically achieve refined management of power electronic devices, it also has many defects. First, the design and implementation of its control system is relatively complex, which undoubtedly increases the R&D cost and technical difficulty. Secondly, since the scheme involves digital circuits, it is very susceptible to interference in a complex electromagnetic environment. Once the program inside the core processor runs out of control or fails, the entire system will not be able to operate according to the expected control logic, which will seriously affect the normal operation of the UUV and may even cause the mission to fail. Summary of the invention

[0007] In view of this, an object of the present invention is to provide an underwater unmanned vehicle driving circuit and a dual-mode power conversion method to solve the related technical problems existing in the prior art. According to a first aspect of an embodiment of the present invention, there is provided an underwater unmanned vehicle driving circuit, the circuit comprising: Power conversion unit, hysteresis comparison unit and PWM control unit; The power conversion unit is used to receive the switch signal containing duty cycle information output by the PWM control unit, control the three-phase six bridge arms to open and close in different combinations, invert the bus DC voltage DC+ into a three-phase AC sinusoidal voltage, output it from the UVW three-phase, and drive the motor to rotate at a specified speed; The hysteresis comparison unit is used to monitor the motor bus current in the power conversion unit. When the bus current value is greater than a preset value, a control high level signal is obtained. When the bus current value is less than the preset value, a control low level signal is obtained, and the obtained level signal is fed back to the PWM control unit. The PWM control unit is used to determine the working mode of the power conversion unit and the on-off selection of multiple power devices connected in parallel in the same bridge arm based on the level signal fed back by the hysteresis comparison unit; The working modes of the power conversion unit include: cruising mode and pursuit mode.

[0008] Furthermore, the power conversion unit comprises: The double-tube or multi-tube parallel connection method is adopted, and the UVW three-phase six-bridge arm is mainly composed of preset power electronic devices. Each bridge arm contains a preset MOS tube and peripheral resistor, and receives a switch signal containing duty cycle information to invert the bus DC voltage into a three-phase AC sinusoidal voltage to drive the motor; The preset power electronic devices include: MOSFET, IGBT, and SiC.

[0009] Furthermore, the power conversion unit adopts a dual-tube parallel MOSFET, comprising: UVW three-phase six bridge arms, UVW three-phase each has an upper and lower bridge arm, each bridge arm contains a MOS tube and a driving resistor and a discharge resistor; wherein the driving resistor controls the on-off speed of the MOS tube through different resistance values; the discharge resistor is used to release the energy stored in the parasitic capacitor of the preset end.

[0010] Furthermore, the hysteresis comparison unit comprises: Current sensor, filter capacitor, RC filter circuit, comparator, comparison voltage configuration resistor, hysteresis bandwidth configuration resistor; The current sensor is used to collect the motor bus current and output a voltage signal containing current information; The filter capacitor is connected to the current sensor and is used to filter out clutter and high-frequency interference in the output signal of the current sensor; The RC filter circuit is connected in series on the output path of the current sensor, and is used to filter the voltage signal containing the current information; The first end of the comparator receives the filtered voltage signal containing current information, and the other end is connected to the corresponding reference voltage through the comparison voltage configuration resistor to determine the upper and lower thresholds of the hysteresis comparison; The hysteresis bandwidth configuration resistor is connected to the comparator and is used to set the width of the hysteresis and control the influence of current fluctuation on the control signal.

[0011] Furthermore, the PWM control unit is composed of a logic control chip, wherein pins 48 and 25 of the chip are used as output control pins for on-off control of two groups of output signals generated by the PWM signal input by the main control end.

[0012] According to a second aspect of an embodiment of the present invention, a method for dual-mode power conversion of an underwater unmanned vehicle driving circuit is provided, which is applied to any of the above-mentioned underwater unmanned vehicle driving circuits, and the method comprises: Obtaining preset instructions; the preset instructions include: cruise instructions and pursuit instructions; Utilizing the acquired preset instruction, executing a mode corresponding to the instruction; If the preset instruction is a cruise instruction, executing the cruise mode based on the first preset rule; If the preset instruction is a pursuit instruction, the pursuit mode is executed based on the second preset rule.

[0013] Further, if the preset instruction is a cruise instruction, executing the cruise mode based on the first preset rule includes: Based on the cruise command, a PWM signal for driving a power device to turn on and off is generated, and a PWM signal for driving a group of preset power devices to work is obtained by using the PWM signal for driving a power device to turn on and off; By utilizing the PWM signal of the power device, the preset DC bus voltage is inverted into a three-phase AC voltage for driving the power motor according to a preset control law through the preset power device, and the drive motor rotates at a specified speed.

[0014] Furthermore, if the preset instruction is a pursuit instruction, executing the pursuit mode based on the second preset rule includes: Based on the pursuit instruction, the duty cycle of the PWM signal is increased, and the increased duty cycle of the PWM signal is used to drive the bus current to increase until a preset hysteresis unit upper limit threshold is reached, thereby obtaining a first signal; The first signal is used to drive a preset second group of power devices to turn on, and the two groups of power devices work synchronously.

[0015] The technical solution provided by the embodiments of the present invention may have the following beneficial effects: 1. In cruise mode, only one set of power devices works, converting the DC bus voltage into three-phase AC voltage for the drive motor according to actual needs, avoiding unnecessary power loss. In pursuit mode, high power output is achieved through the coordinated work of two sets of power devices, and the switching of power devices can be reasonably controlled during mode switching, reducing switching losses, improving overall energy utilization efficiency, and extending the endurance of the aircraft.

[0016] 2. When two groups of power devices work simultaneously in pursuit mode, they can share the heat, preventing a single power device from being subjected to excessive heat for a long time, reducing the risk of device damage due to overheating, and improving the reliability and stability of the system. At the same time, it helps to reduce the size and complexity of the heat dissipation device, making the overall structure of the aircraft more compact.

[0017] 3. It can quickly and accurately switch working modes according to preset instructions (cruise instructions and pursuit instructions) to meet the power requirements of underwater unmanned vehicles in different mission scenarios. It can maintain stable and efficient operation during cruising to save energy; it can quickly increase power during pursuit to achieve high-speed navigation, enhance the adaptability of the vehicle to complex mission environments, and improve the success rate of mission execution.

[0018] 4. In the maintenance mode, the two groups of power devices can work alternately by adjusting the wiring method, which reduces the working time and fatigue level of a single power device, evenly distributes the wear and tear of the device, effectively extends the service life of the power device and the entire system, reduces the cost of equipment maintenance and replacement, and improves the economy and practicality of the aircraft.

[0019] 5. The setting of the hysteresis unit can accurately monitor the bus current and control the opening of the power device, preventing the repeated conversion of the control signal caused by current fluctuations, and ensuring the stability of the system during the conversion and operation of different modes. At the same time, the precise control of signals (such as PWM signals) and currents in each mode ensures the stable operation of the power motor and reduces the impact of unstable electrical parameters on the performance of the aircraft.

[0020] It is understandable that the technical solution provided by the present invention, it should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] Figure 1 is a schematic diagram of a driving circuit of an underwater unmanned vehicle according to an exemplary embodiment; Figure 2is a specific implementation flow chart of an underwater unmanned vehicle driving circuit based on dual-tube parallel MOSFET according to an exemplary embodiment; Figure 3 The present invention is a schematic block diagram of a method flow of dual-mode power conversion of an underwater unmanned vehicle driving circuit according to an exemplary embodiment. DETAILED DESCRIPTION

[0023] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0024] Embodiment 1 See also Figure 1 , Figure 1 is a schematic diagram of a driving circuit of an underwater unmanned vehicle according to an exemplary embodiment, the circuit comprising: A power conversion unit 1, a hysteresis comparison unit 2 and a PWM control unit 3; The power conversion unit 1 is used to receive the switch signal containing duty cycle information output by the PWM control unit 3, control the three-phase six bridge arms to open and close in different combinations, invert the bus DC voltage DC+ into a three-phase AC sinusoidal voltage, output it from the UVW three-phase, and drive the motor to rotate at a specified speed; The hysteresis comparison unit 2 is used to monitor the motor bus current in the power conversion unit 1. When the bus current value is greater than a preset value, a control high level signal is obtained. When the bus current value is less than the preset value, a control low level signal is obtained, and the obtained level signal is fed back to the PWM control unit 3. The PWM control unit 3 is used to determine the working mode of the power conversion unit 1 and the on-off selection of multiple power devices connected in parallel in the same bridge arm based on the level signal fed back by the hysteresis comparison unit 2; The working modes of the power conversion unit 1 include: a cruise mode and a pursuit mode.

[0025] In a specific implementation, the power conversion unit 1 includes: The double-tube or multi-tube parallel connection method is adopted, and the UVW three-phase six-bridge arm is mainly composed of preset power electronic devices. Each bridge arm contains a preset MOS tube and peripheral resistor, and receives a switch signal containing duty cycle information to invert the bus DC voltage into a three-phase AC sinusoidal voltage to drive the motor; The preset power electronic devices include: MOSFET, IGBT, and SiC.

[0026] In one embodiment, Figure 2 As shown, the power conversion unit 1 adopts a dual-tube parallel MOSFET, including: UVW three-phase six bridge arms, UVW three-phase each has an upper and lower bridge arm, each bridge arm contains a MOS tube and a driving resistor and a discharge resistor; wherein the driving resistor controls the on-off speed of the MOS tube through different resistance values; the discharge resistor is used to release the energy stored in the parasitic capacitor of the preset end.

[0027] In the specific implementation, taking the dual-tube parallel MOSFET as an example, this part of the circuit includes 6 bridge arms of three phases UVW. The upper bridge arm of the U phase is composed of MOS tubes Q1, Q2 and peripheral resistors R11, R12, R19, and R20. R11 and R12 are driving resistors, and the on and off speed of the MOS tube is controlled by different resistance values. R19 and R20 are discharge resistors, which are used to release the energy stored in the parasitic capacitance at both ends of GS. The lower bridge arm of the U phase is composed of MOS tubes Q7, Q8 and peripheral resistors R17, R18, R25, and R26. The upper bridge arm of the V phase is composed of MOS tubes Q3, Q4 and peripheral resistors R7, R8, R21, and R22. The lower bridge arm of the V phase is composed of MOS tubes Q9, Q10 and peripheral resistors R13, R16, R27, and R28. The W-phase upper bridge arm is composed of MOS tubes Q5, Q6 and peripheral resistors R9, R10, R23, and R24, and the W-phase lower bridge arm is composed of MOS tubes Q11, Q12 and peripheral resistors R14, R15, R29, and R30. The power conversion unit 1 receives the switching signal (UgH, UgL, VgH, VgL, WgH, and WgL) containing duty cycle information, controls the three-phase six bridge arms to open and close in different combinations, and inverts the bus DC voltage DC+ into a three-phase AC sinusoidal voltage, which is output from the UVW three-phase to drive the motor to rotate at a specified speed.

[0028] In a specific implementation, the hysteresis comparison unit 2 includes: Current sensor, filter capacitor, RC filter circuit, comparator, comparison voltage configuration resistor, hysteresis bandwidth configuration resistor; The current sensor is used to collect the motor bus current and output a voltage signal containing current information; The filter capacitor is connected to the current sensor and is used to filter out clutter and high-frequency interference in the output signal of the current sensor; The RC filter circuit is connected in series on the output path of the current sensor, and is used to filter the voltage signal containing the current information; The first end of the comparator receives the filtered voltage signal containing current information, and the other end is connected to the corresponding reference voltage through the comparison voltage configuration resistor to determine the upper and lower thresholds of the hysteresis comparison; The hysteresis bandwidth configuration resistor is connected to the comparator and is used to set the width of the hysteresis and control the influence of current fluctuation on the control signal.

[0029] In specific implementation, Figure 2 As shown in FIG. 1 , the unit is mainly composed of a current sensor U2, a sensor filter capacitor C3, a current RC filter circuit (C4, R6), a comparator U1, a comparator filter capacitor C1, a comparison voltage configuration resistor (R2, R5), an RC filter circuit (R3, C2), and a hysteresis bandwidth configuration resistor (R1, R4). The current sensor U2 collects the motor bus current, and its output is connected in parallel with the sensor filter capacitor C3 and then connected to the current RC filter circuit C4, R6. The filtered signal is sent to one input end of the comparator U1. The comparison voltage configuration resistors R2 and R5 are connected in series and then connected to the other input end of the comparator U1 to determine the threshold of the hysteresis comparison. The RC filter circuits R3 and C2 are connected in parallel to the input end to further stabilize the reference voltage. The output end of the comparator U1 is connected to the comparator filter capacitor C1, and the hysteresis bandwidth configuration resistors R1 and R4 are connected in the feedback loop of the comparator U1.

[0030] In the specific implementation, the current sensor U2 collects the motor bus current and outputs the voltage signal Ibus containing the current information, which is sent to the comparator U1 after filtering. The comparator U1 compares the Ibus signal with the reference voltage set by R2 and R5. When the current value is greater than the upper limit of the hysteresis loop, the Control1 signal becomes a high level; when the current value is less than the lower limit of the hysteresis loop, the Control1 signal becomes a low level. Through the hysteresis control method, when the current value fluctuates between the upper and lower limits, the Control1 signal can be prevented from repeatedly jumping, ensuring the stable operation of the system, thereby realizing the on-off selection control of multiple power devices in parallel on the same bridge arm, playing a key role in regulation and stabilization in the drive circuit of the underwater unmanned vehicle.

[0031] It should be noted that the function of the hysteresis comparison unit 2 is to collect the bus current driven by the motor. When the bus current value is greater than the preset value, a high-level control signal is obtained. When the bus current value is less than the preset value, a low-level control signal is obtained. The hysteresis control method is used to prevent the current value from fluctuating, causing repeated changes in the control signal and affecting the stability of the system.

[0032] In specific implementation, the PWM control unit 3 is composed of a logic control chip U3. Pins 48 and 25 of the chip are output control pins, which perform on-off control on the two sets of output signals generated by the PWM signal input from the main control end. When the Control1 signal is at a high level, the output of the signals UgH1~WgL1 is enabled, and when the Control1 signal is at a low level, the output of the signals UgH1~WgL1 is prohibited. When the Control2 signal is at a high level, the output of the signals UgH2~WgL2 is enabled, and when the Control2 signal is at a low level, the output of the signals UgH2~WgL2 is prohibited. Through the PWM control unit 3, the on-off selection of multiple power devices in parallel in the same bridge arm is completed.

[0033] In specific implementation, the purpose of the present invention is to provide an energy-saving driving circuit for an unmanned aerial vehicle, so that the UUV can realize a high-power motor driving function through a multi-tube parallel driving method in a short-term pursuit mode, and complete the functions of rapid acceleration and high-speed travel of the UUV. In a long-term cruising mode, a single-tube driving method is used to complete the driving function, reduce the conduction loss caused by the simultaneous opening and closing of multiple power devices, reduce the loss of the driver in the long-term cruising mode, reduce power consumption, improve driving efficiency, save battery (power) energy, extend the cruising time, and achieve energy-saving control.

[0034] See also Figure 3 , Figure 3 The present invention is a schematic block diagram of a method for dual-mode power conversion of an underwater unmanned vehicle driving circuit according to an exemplary embodiment, wherein the method comprises: S1. Get preset instructions; the preset instructions include: cruise instructions, pursuit instructions; S2. Using the preset instruction obtained, execute the mode corresponding to the instruction; S3. If the preset instruction is a cruise instruction, the cruise mode is executed based on the first preset rule; S4. If the preset instruction is a pursuit instruction, executing a pursuit mode based on a second preset rule.

[0035] In one embodiment, if the preset instruction is a cruise instruction, executing the cruise mode based on a first preset rule includes: Based on the cruise command, a PWM signal for driving a power device to turn on and off is generated, and a PWM signal for driving a group of preset power devices to work is obtained by using the PWM signal for driving a power device to turn on and off; By utilizing the PWM signal of the power device, the preset DC bus voltage is inverted into a three-phase AC voltage for driving the power motor according to a preset control law through the preset power device, and the drive motor rotates at a specified speed.

[0036] In one embodiment, if the preset instruction is a pursuit instruction, executing the pursuit mode based on the second preset rule includes: Based on the pursuit instruction, the duty cycle of the PWM signal is increased, and the increased duty cycle of the PWM signal is used to drive the bus current to increase until a preset hysteresis unit upper limit threshold is reached, thereby obtaining a first signal; The first signal is used to drive a preset second group of power devices to turn on, and the two groups of power devices work synchronously.

[0037] In specific implementation, the working principle of the energy-saving drive circuit of the underwater vehicle is as follows: after the system is powered on, the current on the bus of the power motor drive circuit is 0, the Control1 signal is low level, and the Control2 signal is set to high level through the pull-up circuit. When the UUV receives the cruise command, the system generates a PWM signal (UgH~WgL) that drives the power device to turn on and off. After entering the energy-saving circuit, it is converted into a PWM signal (UgH2~WgL2) that drives a group of power devices (Q2, Q4, Q6, Q8, Q10, Q12) to work. This group of power devices inverts the DC bus voltage into a three-phase AC voltage that drives the power motor to work according to the control law. The motor drives the propeller to rotate to realize the cruise operation of the UUV. When the UUV receives the pursuit command, the duty cycle of the PWM signal generated by the system increases, and the bus current of the driving part increases after acting on the motor until it reaches the upper limit threshold of the hysteresis unit, and the Control1 signal is converted to a high level. At this time, the second group of power devices (Q1, Q3, Q5, Q7, Q9, Q11) are turned on, and the two groups of power devices work at the same time to achieve high-power output of the driver, while sharing heat and improving heat dissipation efficiency. The power motor is in a high-speed and high-power working state, allowing the UUV to achieve the power indicators of the pursuit mode. When the UUV re-enters the cruise mode, the bus current of the driving part gradually decreases until it is lower than the lower limit of the hysteresis unit, and Control1 is converted to a low level again, the second group of power devices is turned off, and only the first group of power devices is in the working mode, reducing the switching loss of the power devices and completing energy saving. When the UUV has been working for a certain period of time, or has completed its mission and returned for maintenance, the wiring method of control1 and control2 can be adjusted to put the second group of power devices (Q1, Q3, Q5, Q7, Q9, Q11) into long-term working mode, and the first group of power devices can be turned on only in high-power state, so as to achieve alternating operation of the two groups of power devices and extend the life of the devices and the system.

[0038] In specific implementation, the present invention adopts a pure hardware method to achieve system energy saving. In the low-speed cruising mode and the high-speed pursuit mode, different control schemes are adopted to achieve efficiency improvement and energy saving, and extend the cruising time of the UUV. The pure hardware method does not require the participation of the CPU control chip, so the response speed of the controller is significantly improved. It is independent and does not rely on CPU control instructions, which reduces the complexity of system control. It is not easily affected by external environmental interference such as electromagnetic interference, has a low error rate, high reliability, and a simple system composition with low cost. At the same time, the control signals can be swapped during maintenance to put multiple groups of power devices in long-term working mode respectively, thereby extending the service life of the system.

[0039] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0040] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0041] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0042] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0043] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0044] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0045] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0047] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An underwater unmanned vehicle driving circuit, characterized in that: The circuit comprises: Power conversion unit, hysteresis comparison unit and PWM control unit; The power conversion unit is used to receive the switch signal containing duty cycle information output by the PWM control unit, control the three-phase six bridge arms to open and close in different combinations, invert the bus DC voltage DC+ into a three-phase AC sinusoidal voltage, output it from the UVW three-phase, and drive the motor to rotate at a specified speed; The hysteresis comparison unit is used to monitor the motor bus current in the power conversion unit. When the bus current value is greater than a preset value, a control high level signal is obtained. When the bus current value is less than the preset value, a control low level signal is obtained, and the obtained level signal is fed back to the PWM control unit. The PWM control unit is used to determine the working mode of the power conversion unit and the on-off selection of multiple power devices connected in parallel in the same bridge arm based on the level signal fed back by the hysteresis comparison unit; The working modes of the power conversion unit include: cruising mode and pursuit mode.

2. The underwater unmanned vehicle driving circuit according to claim 1, characterized in that: The power conversion unit comprises: The double-tube or multi-tube parallel connection method is adopted, and the UVW three-phase six-bridge arm is mainly composed of preset power electronic devices. Each bridge arm contains a preset MOS tube and peripheral resistor, and receives a switch signal containing duty cycle information to invert the bus DC voltage into a three-phase AC sinusoidal voltage to drive the motor; The preset power electronic devices include: MOSFET, IGBT, and SiC.

3. The underwater unmanned vehicle driving circuit according to claim 2, characterized in that: The power conversion unit adopts a dual-tube parallel MOSFET, including: UVW three-phase six bridge arms, UVW three-phase each has an upper and lower bridge arm, each bridge arm contains a MOS tube and a driving resistor and a discharge resistor; wherein the driving resistor controls the on-off speed of the MOS tube through different resistance values; the discharge resistor is used to release the energy stored in the parasitic capacitor of the preset end.

4. The underwater unmanned vehicle driving circuit according to claim 1, characterized in that: The hysteresis comparison unit comprises: Current sensor, filter capacitor, RC filter circuit, comparator, comparison voltage configuration resistor, hysteresis bandwidth configuration resistor; The current sensor is used to collect the motor bus current and output a voltage signal containing current information; The filter capacitor is connected to the current sensor and is used to filter out clutter and high-frequency interference in the output signal of the current sensor; The RC filter circuit is connected in series on the output path of the current sensor, and is used to filter the voltage signal containing the current information; The first end of the comparator receives a filtered voltage signal containing current information, and the other end is connected to a corresponding reference voltage through a comparison voltage configuration resistor to determine the upper and lower thresholds of the hysteresis comparison; The hysteresis bandwidth configuration resistor is connected to the comparator and is used to set the width of the hysteresis and control the influence of current fluctuation on the control signal.

5. The underwater unmanned vehicle driving circuit according to claim 1, characterized in that: Said The PWM control unit is composed of a logic control chip, in which pins 48 and 25 of the chip are used as output control pins to control the on / off of the two sets of output signals generated by the PWM signal input from the main control end.

6. A method for dual-mode power conversion of an underwater unmanned vehicle driving circuit, applied to the underwater unmanned vehicle driving circuit according to any one of claims 1 to 5, characterized in that: The method comprises: Obtaining preset instructions; the preset instructions include: cruise instructions and pursuit instructions; Utilizing the acquired preset instruction, executing a mode corresponding to the instruction; If the preset instruction is a cruise instruction, executing the cruise mode based on the first preset rule; If the preset instruction is a pursuit instruction, the pursuit mode is executed based on the second preset rule.

7. The method according to claim 6, characterized in that If the preset instruction is a cruise instruction, executing the cruise mode based on the first preset rule includes: Based on the cruise command, a PWM signal for driving a power device to turn on and off is generated, and a PWM signal for driving a group of preset power devices to work is obtained by using the PWM signal for driving a power device to turn on and off; By utilizing the PWM signal of the power device, the preset DC bus voltage is inverted into a three-phase AC voltage for driving the power motor according to a preset control law through the preset power device, and the drive motor rotates at a specified speed.

8. The method according to claim 6, characterized in that If the preset instruction is a pursuit instruction, executing the pursuit mode based on the second preset rule includes: Based on the pursuit instruction, the duty cycle of the PWM signal is increased, and the increased duty cycle of the PWM signal is used to drive the bus current to increase until a preset hysteresis unit upper limit threshold is reached, thereby obtaining a first signal; The first signal is used to drive a preset second group of power devices to turn on, and the two groups of power devices work synchronously.

Images