Electric wheelchair system and method using sliding mode synchronous control and magnetic field oriented control

Abstract

The present invention discloses an electric wheelchair system utilizing sliding-mode synchronous control and magnetic field-oriented control. This system, belonging to the field of electric wheelchair control technology, comprises a rocker controller, a motor drive module, and a control assembly. Both the left signal acquisition module and the right signal acquisition module include a sliding-mode synchronous control processor and a magnetic field-oriented control processor. The magnetic field-oriented control processor is connected to the sliding-mode synchronous control processor. The magnetic field-oriented control processor is configured to obtain a speed deviation between the left and right motors when the motor drive module experiences significant torque pulsation. After obtaining this speed deviation, the sliding-mode synchronous control processor synchronizes the speeds of the left and right motors. This solution addresses the issues of existing electric wheelchair systems using square-wave control systems, which can result in significant torque pulsation, unstable rotation, and poor noise performance in the drive unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric wheelchair control, and in particular relates to an electric wheelchair system and method using sliding mode synchronous control and magnetic field oriented control. Background Art

[0002] As the aging population in my country deepens, more and more elderly people have difficulty in moving as they age. Electric wheelchairs are considered to be the most commonly used means of transportation and have become an indispensable means of transportation in the lives of many elderly people.

[0003] The brushless DC motors in electric wheelchairs on the market typically use square-wave drive. This simple, low-cost control method makes it widely used in electric vehicle solutions. However, using square-wave controllers in electric wheelchairs also has drawbacks. The current surges during commutation in square-wave drive can lead to large torque ripples and poor noise performance. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide an electric wheelchair system and method using sliding mode synchronous control and magnetic field oriented control, which can solve the problems of using a square wave control system in existing electric wheelchair systems, thereby causing large torque pulsation of the drive device, unstable rotation, and poor noise performance.

[0005] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0006] In a first aspect, an embodiment of the present invention provides an electric wheelchair system with sliding mode synchronous control and magnetic field oriented control, comprising:

[0007] Joystick controller, motor drive module and control components,

[0008] The rocker controller is connected to the motor drive module,

[0009] The motor drive module includes a dual-motor controller, a left inverter, a right inverter, a left motor, a right motor, a left signal acquisition module and a right signal acquisition module. The input end of the dual-motor controller is connected to the output end of the rocker controller, and the output end of the dual-motor controller is respectively connected to the input end of the left inverter and the right inverter. The output end of the left inverter is connected to the input end of the left motor, and the output end of the right inverter is connected to the input end of the right motor. The left motor is also connected to the dual-motor controller through the left signal acquisition module, and the right motor is also connected to the dual-motor controller through the right signal acquisition module.

[0010] The control assembly includes a left reducer, a left wheel, a right reducer and a right wheel, the output end of the left motor is connected to the input end of the left reducer, the input end of the left reducer is connected to the left wheel, the output end of the right motor is connected to the input end of the right reducer, and the input end of the right reducer is connected to the right wheel;

[0011] Among them, the left signal acquisition module and the right signal acquisition module both have a sliding mode synchronization control processor and the magnetic field oriented control processor. The magnetic field oriented control processor is connected to the sliding mode synchronization control processor. The magnetic field oriented control processor is used to obtain the speed deviation value of the left motor and the right motor when the torque pulsation of the motor drive module is large. The sliding mode synchronization control processor is used to synchronize the speeds of the left motor and the right motor after obtaining the speed deviation value of the left motor and the right motor.

[0012] Optionally, the dual motor controller includes: a left PI speed regulator, a left PI current regulator, a left Park inverter, a left space vector modulator, a right PI speed regulator, a right PI current regulator, a right Park inverter, a right space vector modulator,

[0013] The left PI speed regulator is connected to the left PI current regulator, the left PI current regulator is connected to the left Park inverter, the left Park inverter is connected to the left space vector modulator, and the left space vector modulator is connected to the left inverter.

[0014] The right PI speed regulator is connected to the right PI current regulator, the right PI current regulator is connected to the right Park inverter, the right Park inverter is connected to the right space vector modulator, and the right space vector modulator is connected to the right inverter.

[0015] Optionally, the electric wheelchair system with sliding mode synchronous control and magnetic field oriented control further includes a Hall sensor, which is connected to the left motor and the right motor respectively. The Hall sensor is used to obtain the position value and speed value of the rotor in the left motor, as well as the position value and speed value of the rotor in the right motor, thereby obtaining the speed deviation value of the left motor and the right motor.

[0016] Optionally, the dual-motor controller also includes a sampling resistor, and the left motor and the right motor are respectively connected through the sampling resistor. The sampling resistor is used to sample the three-phase current in the left motor and the right motor respectively, and transmit the three-phase current of the left motor and the three-phase current of the right motor to the left PI current regulator and the right PI current regulator, thereby performing speed compensation for the left motor and the right motor.

[0017] In a second aspect, an embodiment of the present invention provides a sliding mode synchronous control and magnetic field oriented control method for an electric wheelchair. The sliding mode synchronous control and magnetic field oriented control method for an electric wheelchair system according to the first aspect includes: sending a target speed value and a steering control instruction to a left motor and a right motor;

[0018] respectively obtaining a first three-phase stator current value of the left motor and a first three-phase stator current value of the right motor, and obtaining a speed deviation value of the left motor and the right motor;

[0019] The speed deviation value of the left motor and the right motor is fed back to the dual-motor controller through sliding mode synchronization control, and the dual-motor controller corrects the first three-phase stator current value of the left motor and the right motor to obtain the second three-phase stator current value of the left motor and the right motor.

[0020] The second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control instruction direction. The right wheel rotates synchronously with the left wheel and reaches the target speed value and the steering control instruction direction.

[0021] Optionally, the electric wheelchair includes a Hall sensor, and obtaining the rotational speed deviation value of the left motor and the right motor specifically includes:

[0022] Obtaining the rotational speed values ​​of the left motor and the right motor according to the pulse number of the Hall sensor;

[0023] Obtaining rotor position information of the left motor and the right motor according to the signal of the Hall sensor;

[0024] A rotational speed deviation value between the left motor and the right motor is obtained according to the rotational speed values ​​of the left motor and the right motor.

[0025] Optionally, the electric wheelchair has a sampling resistor, and obtaining the first three-phase stator current value of the left motor and the first three-phase stator current value of the right motor specifically includes:

[0026] The sampling resistor samples the three-phase current of the left motor and the right motor respectively, and obtains the three-phase stator current values ​​of the left motor and the right motor;

[0027] The three-phase stator current values ​​of the left motor and the right motor are respectively denoted as i a 、i b and i cThe three-phase stator current values ​​of the left motor and the right motor are transformed by Clark and Park to obtain the components i of the d-axis and q-axis of the two-phase synchronous rotating coordinate system. d and i q , and recorded as the first three-phase stator current value of the left motor and the right motor.

[0028] Optionally, the sliding mode synchronous control adopts the formula:

[0029] in, is the electromagnetic torque of the left motor and the right motor; is the number of pole pairs of the left motor and the right motor; is the permanent magnet flux of the rotor of the left motor and the right motor; is the q-axis current component of the left motor and the right motor, is the load torque of the left motor and the right motor; is the load disturbance experienced by the left and right motors; are the moment of inertia and friction coefficient on the left and right motor shafts; is the rotor electrical angular velocity of the left motor and the right motor; and All are positive numbers; is a symbolic function that returns The positive and negative signs; for The derivative of .

[0030] Optionally, the dual-motor controller includes a PI current regulator. After the dual-motor controller corrects the first three-phase stator current values ​​of the left motor and the right motor to obtain the second three-phase stator current values ​​of the left motor and the right motor, the dual-motor controller further includes:

[0031] The second three-phase stator current value is fed back to the PI current regulator, and the PI current regulator re-controls the left motor and the right motor according to the second three-phase stator current value.

[0032] Optionally, the second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control command direction, and the right wheel rotates synchronously with the left wheel to achieve the target speed value and the steering control command direction, specifically including:

[0033] The second three-phase stator current values ​​of the left motor and the right motor pass through the inverter to obtain a three-phase inverter signal.

[0034] The three-phase inverter signal controls the rotation of the left motor and the right motor respectively;

[0035] The left motor and the right motor rotate the left wheel through a reducer to achieve the target speed value and the steering control instruction direction, and the right wheel rotates synchronously with the left wheel to achieve the target speed value and the steering control instruction direction.

[0036] In a third aspect, an embodiment of the present invention provides a device, including:

[0037] processor;

[0038] a memory for storing processor-executable instructions;

[0039] The processor is configured to call instructions stored in the memory to execute the method of the second aspect.

[0040] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having computer program instructions stored thereon, which implement the method of the second aspect when the computer program instructions are executed by a processor.

[0041] In an embodiment of the present invention, a sliding-mode synchronous control method is employed to replace the traditional PI synchronous controller to improve the speed synchronization performance of the left and right motors. When the parameters of the two motors are completely identical, if the speeds become asynchronous due to different load disturbances, the sliding-mode synchronous control method can restore steady state within a certain period of time, achieving speed synchronization between the left and right motors. Furthermore, the rotor-field-oriented control method is used to control the left and right motors, resolving the large torque ripple, unstable rotation, and poor noise performance of the drive device caused by existing square-wave control schemes. Furthermore, this method relies on a software-defined control algorithm, eliminating the need for additional hardware costs, making it simple for electric wheelchair users to operate and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a control block diagram of an electric wheelchair system with sliding mode synchronization control and magnetic field oriented control provided by an embodiment of the present invention;

[0043] Figure 2 This is a control block diagram of another electric wheelchair system with sliding mode synchronization control and magnetic field oriented control provided by an embodiment of the present invention;

[0044] Figure 3 The figure is a flow chart of an electric wheelchair system with sliding mode synchronous control and magnetic field oriented control provided by an embodiment of the present invention.

[0045] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0047] The terms "first", "second", etc. in the description and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. It should be understood that in the various embodiments of the present disclosure, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure.

[0048] It should be understood that in the present disclosure, "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product or apparatus.

[0049] It should be understood that in the present disclosure, "plurality" refers to two or more. "And / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "Contains A, B and C", "Contains A, B, C" means that A, B, and C are all included, "Contains A, B or C" means that one of A, B, and C is included, and "Contains A, B and / or C" means that any one, any two, or any three of A, B, and C are included.

[0050] It should be understood that, in this disclosure, "B corresponding to A," "B corresponding to A," "A corresponds to B," or "B corresponds to A" means that B is associated with A and B can be determined based on A. Determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information. A and B match when the similarity between A and B is greater than or equal to a preset threshold.

[0051] Depending on the context, "if" as used herein may be interpreted as "when" or "when" or "in response to determining" or "in response to detecting."

[0052] The electric wheelchair system and method for sliding mode synchronous control and magnetic field oriented control provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios. Example

[0053] Reference Figure 1 , shows a control block diagram of an electric wheelchair system with sliding mode synchronization control and magnetic field oriented control provided by an embodiment of the present invention.

[0054] An embodiment of the present invention provides an electric wheelchair system with sliding mode synchronous control and magnetic field oriented control, comprising:

[0055] Joystick controller 1, motor drive module and control components,

[0056] The rocker controller 1 is connected to the motor drive module.

[0057] The motor drive module includes a dual-motor controller 2, a left inverter 4, a right inverter 5, a left motor 7, a right motor 8, a left signal acquisition module 3 and a right signal acquisition module 6. The input end of the dual-motor controller 2 is connected to the output end of the rocker controller 1, and the output end of the dual-motor controller 2 is connected to the input ends of the left inverter 4 and the right inverter 5 respectively. The output end of the left inverter 4 is connected to the input end of the left motor 7, and the output end of the right inverter 5 is connected to the input end of the right motor 8. The left motor is also connected to the dual-motor controller 2 through the left signal acquisition module 3, and the right motor 8 is also connected to the dual-motor controller 2 through the right signal acquisition module 6;

[0058] The control assembly includes a left reducer 9, a left wheel 11, a right reducer 10 and a right wheel 12. The output end of the left motor is connected to the input end of the left reducer, the input end of the left reducer is connected to the left wheel, the output end of the right motor is connected to the input end of the right reducer, and the input end of the right reducer is connected to the right wheel;

[0059] Among them, the left signal acquisition module and the right signal acquisition module both have a sliding mode synchronization control processor and the magnetic field oriented control processor. The magnetic field oriented control processor is connected to the sliding mode synchronization control processor. The magnetic field oriented control processor is used to obtain the speed deviation value of the left motor and the right motor when the torque pulsation of the motor drive module is large. The sliding mode synchronization control processor is used to synchronize the speeds of the left motor and the right motor after obtaining the speed deviation value of the left motor and the right motor.

[0060] Optionally, refer to Figure 2 , shows a control block diagram of an electric wheelchair system with sliding mode synchronous control and magnetic field oriented control provided by an embodiment of the present invention. The dual-motor controller includes: a left PI speed regulator S102, a left PI current regulator S104, a left Park inverter S106, a left space vector modulator (SVPMW) S111, a right PI speed regulator S103, a right PI current regulator S105, a right Park inverter S108, and a right space vector modulator (SVPMW) S112. The left PI speed regulator is connected to the left PI current regulator, the left PI current regulator is connected to the left Park inverter, the left Park inverter is connected to the left space vector modulator, the left space vector modulator is connected to the left inverter, the right PI speed regulator is connected to the right PI current regulator, the right PI current regulator is connected to the right Park inverter, the right Park inverter is connected to the right space vector modulator, and the right space vector modulator is connected to the right inverter.

[0061] Optionally, the electric wheelchair system with sliding mode synchronous control and magnetic field oriented control further includes a Hall sensor, which is connected to the left motor and the right motor respectively. The Hall sensor is used to obtain the position value and speed value of the rotor in the left motor, as well as the position value and speed value of the rotor in the right motor, thereby obtaining the speed deviation value of the left motor and the right motor.

[0062] This method uses rotor-field-oriented control to control the left and right motors. This method addresses the high torque ripple, unstable rotation, and poor noise levels associated with existing square-wave control systems for electric wheelchairs.

[0063] Optionally, the dual-motor controller also includes a sampling resistor, and the left motor and the right motor are respectively connected through the sampling resistor. The sampling resistor is used to sample the three-phase current in the left motor and the right motor respectively, and transmit the three-phase current of the left motor and the three-phase current of the right motor to the left PI current regulator and the right PI current regulator, thereby performing speed compensation for the left motor and the right motor.

[0064] This scheme designs a control method based on rotor magnetic field orientation to drive the left and right to move at a given speed to control the target speed and forward, backward, left turn, right turn and zero radius rotation of the electric wheelchair.

[0065] In an embodiment of the present invention, a sliding-mode synchronous control method is employed to replace the traditional PI synchronous controller to improve the speed synchronization performance of the left and right motors. When the parameters of the two motors are completely identical, if the speeds become asynchronous due to different load disturbances, the sliding-mode synchronous control method can restore steady state within a certain period of time, achieving speed synchronization between the left and right motors. Furthermore, the rotor-field-oriented control method is used to control the left and right motors, resolving the large torque ripple, unstable rotation, and poor noise performance of the drive device caused by existing square-wave control schemes. Furthermore, this method relies on a software-defined control algorithm, eliminating the need for additional hardware costs, making it simple for electric wheelchair users to operate and easy to implement. Example

[0066] Reference Figure 3 , which shows a flow chart of an electric wheelchair system with sliding mode synchronization control and magnetic field oriented control provided by an embodiment of the present invention.

[0067] A method for an electric wheelchair using sliding mode synchronous control and magnetic field oriented control is applied to any of the above electric wheelchair systems using sliding mode synchronous control and magnetic field oriented control, and is characterized by comprising:

[0068] S201: Sending a target speed value and a steering control instruction to the left motor and the right motor.

[0069] Specifically, the movement of the wheelchair is manually controlled through a joystick. The signal processing algorithm of the joystick's central processor converts a two-dimensional signal into the target speed values ​​and steering control instructions of the left and right motors, and sends them to the STM32 F3 series 32-bit microcontroller through the CAN communication protocol.

[0070] S202: respectively obtaining a first three-phase stator current value of the left motor and a first three-phase stator current value of the right motor, and obtaining a speed deviation value of the left motor and the right motor.

[0071] Optionally, the electric wheelchair includes a Hall sensor, and obtaining the rotational speed deviation value of the left motor and the right motor specifically includes:

[0072] Obtaining the rotational speed values ​​of the left motor and the right motor according to the pulse number of the Hall sensor;

[0073] Obtaining rotor position information of the left motor and the right motor according to the signal of the Hall sensor;

[0074] A rotational speed deviation value between the left motor and the right motor is obtained according to the rotational speed values ​​of the left motor and the right motor.

[0075] Specifically, the Hall sensor is connected to the rotor of the brushless DC motor to collect the position and speed of the DC motor rotor. The motor controller samples the three-phase current of the DC motor through a sampling resistor to obtain the three-phase stator current value.

[0076] S203: The speed deviation value of the left motor and the right motor is fed back to the dual-motor controller after sliding mode synchronization control. The dual-motor controller corrects the first three-phase stator current value of the left motor and the right motor to obtain the second three-phase stator current value of the left motor and the right motor.

[0077] Optionally, the electric wheelchair has a sampling resistor, and obtaining the first three-phase stator current value of the left motor and the first three-phase stator current value of the right motor specifically includes:

[0078] The sampling resistor samples the three-phase current of the left motor and the right motor respectively, and obtains the three-phase stator current values ​​of the left motor and the right motor;

[0079] The three-phase electric stator current values ​​of the left motor and the right motor are respectively denoted as ia, ib and ic, and the three-phase electric stator current values ​​of the left motor and the right motor are subjected to Clark transformation and Park transformation to obtain the components id and iq of the d-axis and q-axis of the two-phase synchronous rotating coordinate system, and are denoted as the first three-phase stator current values ​​of the left motor and the right motor.

[0080] Specifically, a sliding mode synchronous control method is used to design the motor speed synchronization controller based on the speed deviation between the left and right motors. When the actual speeds of the left and right motors differ, the speeds are compared to obtain a speed deviation. This speed deviation is then adjusted by the sliding mode synchronous controller and fed back as a tracking signal to the speed loops of the left and right motors. The tracking signal compensates the speed loops of the left and right motors, with positive compensation for the left motor and negative compensation for the right motor.

[0081] Optionally, the sliding mode synchronous control adopts the formula:

[0082] The speed sliding mode synchronization controller is designed as follows:

[0083] In the formula is the electromagnetic torque of the left and right motors; is the number of pole pairs of the left and right motors; is the permanent magnet flux of the rotor of the left and right motors; is the q-axis current component of the left and right motors.

[0084] The equation of motion for the motor is:

[0085] is the load torque of the left and right motors; is the load disturbance of the left and right motors; are the moment of inertia and friction coefficient on the left and right motor shafts; is the rotor electrical angular velocity of the left and right motors.

[0086] The design of the sliding mode synchronous controller should satisfy the requirement that the system reaches the sliding surface within a finite time under sliding mode synchronous control and maintains near the sliding surface. The sliding surface is designed as follows:

[0087] Take the state variables of the system as:

[0088] in and The actual speed of the left and right motors.

[0089] Combining the previous formula, the state equation of the system can be obtained as:

[0090] Select the sliding surface of the system for:

[0091]

[0092] The control quantity is designed as follows:

[0093] The reaching law in the sliding mode synchronous controller uses the exponential reaching law:

[0094] and All are positive numbers; is a symbolic function that returns The positive and negative signs; for The derivative of .

[0095] The output of the sliding mode synchronization controller is:

[0096]

[0097] Based on stability analysis:

[0098] In order to make the system meet the stability requirements, the Lyapunov function is used to prove the system.

[0099] Choose the Lyapunov function as:

[0100] because and are all constants greater than zero, so no matter positive and negative, and Always different signs, that is Satisfy the stability conditions.

[0101] Optionally, the dual-motor controller includes a PI current regulator. After the dual-motor controller corrects the first three-phase stator current values ​​of the left motor and the right motor to obtain the second three-phase stator current values ​​of the left motor and the right motor, the dual-motor controller further includes:

[0102] The second three-phase stator current value is fed back to the PI current regulator, and the PI current regulator re-controls the left motor and the right motor according to the second three-phase stator current value.

[0103] Specifically, the speed control quantity of the left and right motors obtained after compensation is used as the given speed of the PI speed regulator. The difference between the given speed and the feedback speed is output by the PI speed regulator to form the output control quantity of the speed controller. The output control quantity of the PI speed regulator serves as the input control quantity of the PI current regulator. The output of the speed loop is used as the given value of the d and q axis currents. The deviation signal obtained by comparing it with the actual current component is calculated by the PI current regulator to obtain the d axis stator voltage u d and q-axis stator voltage u q . d and u q Perform inverse Park transformation to the two-phase stationary coordinate system to obtain u α and u β . α and u β The PWM duty cycle is obtained by space vector pulse width modulation technology to generate the control signal of the three-phase inverter.

[0104] S204: The second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control instruction direction, and the right wheel rotates synchronously with the left wheel and reaches the target speed value and the steering control instruction direction.

[0105] Optionally, the second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control command direction, and the right wheel rotates synchronously with the left wheel and achieves the target speed value and the steering control command direction, specifically comprising: the second three-phase stator current values ​​of the left motor and the right motor pass through an inverter to obtain a three-phase inverter signal, and the three-phase inverter signal respectively controls the rotation of the left motor and the right motor;

[0106] The left motor and the right motor rotate the left wheel through a reducer to achieve the target speed value and the steering control instruction direction, and the right wheel rotates synchronously with the left wheel to achieve the target speed value and the steering control instruction direction.

[0107] Example 3

[0108] An embodiment of the present invention provides a device, a processor;

[0109] a memory for storing processor-executable instructions;

[0110] The processor is configured to call the instructions stored in the memory to execute the method described in the second embodiment.

[0111] In an embodiment of the present invention, a sliding-mode synchronous control method is employed to replace the traditional PI synchronous controller to improve the speed synchronization performance of the left and right motors. When the parameters of the two motors are completely identical, if the speeds become asynchronous due to different load disturbances, the sliding-mode synchronous control method can restore steady state within a certain period of time, achieving speed synchronization between the left and right motors. Furthermore, the rotor-field-oriented control method is used to control the left and right motors, resolving the large torque ripple, unstable rotation, and poor noise performance of the drive device caused by existing square-wave control schemes. Furthermore, this method relies on a software-defined control algorithm, eliminating the need for additional hardware costs, making it simple for electric wheelchair users to operate and easy to implement.

[0112] Example 4

[0113] An embodiment of the present invention provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the method described in the second embodiment is implemented.

[0114] In an embodiment of the present invention, a sliding-mode synchronous control method is employed to replace the traditional PI synchronous controller to improve the speed synchronization performance of the left and right motors. When the parameters of the two motors are completely identical, if the speeds become asynchronous due to different load disturbances, the sliding-mode synchronous control method can restore steady state within a certain period of time, achieving speed synchronization between the left and right motors. Furthermore, the rotor-field-oriented control method is used to control the left and right motors, resolving the large torque ripple, unstable rotation, and poor noise performance of the drive device caused by existing square-wave control schemes. Furthermore, this method relies on a software-defined control algorithm, eliminating the need for additional hardware costs, making it simple for electric wheelchair users to operate and easy to implement.

[0115] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or raised-in-groove structure on which instructions are stored, and any suitable combination thereof. As used herein, a computer-readable storage medium is not to be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

[0116] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0117] The computer program instructions for performing the operations of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, the state information of the computer-readable program instructions is used to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), so that the electronic circuit can execute the computer-readable program instructions, thereby implementing various aspects of the present invention.

[0118] Various aspects of the present invention are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0119] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, such that when these instructions are executed by the processing unit of the computer or other programmable data processing device, a device is generated that implements the functions / actions specified in one or more blocks in the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, where these instructions cause the computer, programmable data processing device, and / or other device to operate in a specific manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing various aspects of the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0120] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0121] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction includes one or more executable instructions for realizing the logical function of the specification. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the function or action of the specification, or can be implemented with a combination of dedicated hardware and computer instructions.

[0122] Note that, unless otherwise directly stated, all features disclosed in this specification (including any accompanying claims, abstracts and drawings) may be replaced by alternative features for achieving the same, equivalent or similar purposes. Therefore, unless otherwise explicitly stated, each feature disclosed is only an example of a group of equivalent or similar features. Where used, further, preferably, further and more preferably are a simple starting point for elaborating another embodiment based on the aforementioned embodiment, and the content of the further, preferably, further or more preferably followed by the above embodiment is combined with the aforementioned embodiment as a complete composition of another embodiment. Several further, preferably, further or more preferably settings following the same embodiment can be arbitrarily combined to form another embodiment.

[0123] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. An electric wheelchair system with sliding mode synchronous control and magnetic field oriented control, characterized in that: include: Joystick controller, motor drive module and control components, The rocker controller is connected to the motor drive module, The motor drive module includes a dual-motor controller, a left inverter, a right inverter, a left motor, a right motor, a left signal acquisition module, and a right signal acquisition module. The input end of the dual-motor controller is connected to the output end of the rocker controller, and the output end of the dual-motor controller is connected to the input end of the left inverter and the input end of the right inverter respectively. The output end of the left inverter is connected to the input end of the left motor, and the output end of the right inverter is connected to the input end of the right motor. The left motor is also connected to the dual-motor controller through the left signal acquisition module, and the right motor is also connected to the dual-motor controller through the right signal acquisition module. The control assembly includes a left reducer, a left wheel, a right reducer and a right wheel, the output end of the left motor is connected to the input end of the left reducer, the input end of the left reducer is connected to the left wheel, the output end of the right motor is connected to the input end of the right reducer, and the input end of the right reducer is connected to the right wheel; Among them, both the left signal acquisition module and the right signal acquisition module have a sliding mode synchronization control processor and a magnetic field oriented control processor. The magnetic field oriented control processor is connected to the sliding mode synchronization control processor. The magnetic field oriented control processor is used to obtain the speed deviation value of the left motor and the right motor when the torque pulsation of the motor drive module is large. The sliding mode synchronization control processor is used to synchronize the speeds of the left motor and the right motor after obtaining the speed deviation value of the left motor and the right motor.

2. The electric wheelchair system with sliding mode synchronous control and magnetic field oriented control according to claim 1, characterized in that: The dual motor controller includes: a left PI speed regulator, a left PI current regulator, a left Park inverter, a left space vector modulator, a right PI speed regulator, a right PI current regulator, a right Park inverter, a right space vector modulator, The left PI speed regulator is connected to the left PI current regulator, the left PI current regulator is connected to the left Park inverter, the left Park inverter is connected to the left space vector modulator, and the left space vector modulator is connected to the left inverter. The right PI speed regulator is connected to the right PI current regulator, the right PI current regulator is connected to the right Park inverter, the right Park inverter is connected to the right space vector modulator, and the right space vector modulator is connected to the right inverter.

3. The electric wheelchair system with sliding mode synchronous control and magnetic field oriented control according to claim 2, characterized in that: It also includes a Hall sensor, which is connected to the left motor and the right motor respectively. The Hall sensor is used to obtain the position value and speed value of the rotor in the left motor, as well as the position value and speed value of the rotor in the right motor, thereby obtaining the speed deviation value of the left motor and the right motor.

4. The electric wheelchair system with sliding mode synchronous control and magnetic field oriented control according to claim 3, characterized in that: The dual-motor controller also includes a sampling resistor, through which the left motor and the right motor are respectively connected. The sampling resistor is used to sample the three-phase current in the left motor and the right motor respectively, and transmit the three-phase current of the left motor and the three-phase current of the right motor to the left PI current regulator and the right PI current regulator, thereby performing speed compensation for the left motor and the right motor.

5. A sliding mode synchronous control and magnetic field oriented control electric wheelchair method, applied to the sliding mode synchronous control and magnetic field oriented control electric wheelchair system according to any one of claims 1 to 4, characterized in that: include: Send target speed values ​​and steering control instructions to the left and right motors; respectively obtaining a first three-phase stator current value of the left motor and a first three-phase stator current value of the right motor, and obtaining a speed deviation value of the left motor and the right motor; The speed deviation value of the left motor and the right motor is fed back to the dual-motor controller after sliding mode synchronization control, and the dual-motor controller corrects the first three-phase stator current values ​​of the left motor and the right motor to obtain the second three-phase stator current values ​​of the left motor and the right motor; The second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control instruction direction. The right wheel rotates synchronously with the left wheel and reaches the target speed value and the steering control instruction direction.

6. The electric wheelchair method of sliding mode synchronous control and magnetic field oriented control according to claim 5, characterized in that: The electric wheelchair includes a Hall sensor, and obtaining the rotational speed deviation value of the left motor and the right motor specifically includes: Obtaining the rotational speed values ​​of the left motor and the right motor according to the pulse number of the Hall sensor; Obtaining rotor position information of the left motor and the right motor according to the signal of the Hall sensor; A rotational speed deviation value between the left motor and the right motor is obtained according to the rotational speed values ​​of the left motor and the right motor.

7. The electric wheelchair method of sliding mode synchronous control and magnetic field oriented control according to claim 6, characterized in that: The electric wheelchair has a sampling resistor, and obtaining the first three-phase stator current value of the left motor and the first three-phase stator current value of the right motor specifically includes: The sampling resistor samples the three-phase current of the left motor and the right motor respectively, and obtains the three-phase stator current values ​​of the left motor and the right motor; The three-phase stator current values ​​of the left motor and the right motor are respectively denoted as i a 、i b and i c The three-phase stator current values ​​of the left motor and the right motor are transformed by Clark and Park to obtain the components i of the d-axis and q-axis of the two-phase synchronous rotating coordinate system. d and i q , and recorded as the first three-phase stator current value of the left motor and the right motor.

8. The electric wheelchair method of sliding mode synchronous control and magnetic field oriented control according to claim 6, characterized in that: The sliding mode synchronous control adopts the formula: in, is the electromagnetic torque of the left motor and the right motor; is the number of pole pairs of the left motor and the right motor; is the permanent magnet flux of the rotor of the left motor and the right motor; is the q-axis current component of the left motor and the right motor, is the load torque of the left motor and the right motor; is the load disturbance experienced by the left and right motors; are the moment of inertia and friction coefficient on the left and right motor shafts; is the rotor electrical angular velocity of the left motor and the right motor; and All are positive numbers; is a symbolic function that returns The positive and negative signs; for The derivative of Indicates the actual speed of the left motor; Indicates the actual speed of the right motor.

9. The electric wheelchair method of sliding mode synchronous control and magnetic field oriented control according to claim 8, characterized in that: The dual-motor controller includes a PI current regulator. After the dual-motor controller corrects the first three-phase stator current values ​​of the left motor and the right motor to obtain the second three-phase stator current values ​​of the left motor and the right motor, it further includes: The second three-phase stator current value is fed back to the PI current regulator, and the PI current regulator re-controls the left motor and the right motor according to the second three-phase stator current value.

10. The electric wheelchair method of sliding mode synchronous control and magnetic field oriented control according to claim 9, characterized in that: The second three-phase stator current values ​​of the left motor and the right motor respectively control the rotation of the left wheel to achieve the target speed value and the steering control instruction direction, and the right wheel rotates synchronously with the left wheel to achieve the target speed value and the steering control instruction direction, specifically including: The second three-phase stator current values ​​of the left motor and the right motor pass through the inverter to obtain a three-phase inverter signal. The three-phase inverter signal controls the rotation of the left motor and the right motor respectively; The left motor and the right motor rotate the left wheel through a reducer to achieve the target speed value and the steering control instruction direction, and the right wheel rotates synchronously with the left wheel to achieve the target speed value and the steering control instruction direction.

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