A permanent magnet synchronous motor control system applied to an electric vehicle

Abstract

This invention provides a permanent magnet synchronous motor control system for electric vehicles, comprising: a vehicle state analysis module, a control strategy determination module, and an execution module. The vehicle state analysis module analyzes the current state of the electric vehicle to obtain analysis results. The control strategy determination module determines the control strategy for each motor based on the analysis results of the current state. The execution module executes the control strategy. This permanent magnet synchronous motor control system for electric vehicles comprehensively considers the vehicle state and then executes the corresponding motor drive strategy, thereby meeting the requirements for smooth and safe operation of the electric vehicle.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a permanent magnet synchronous motor control system for electric vehicles. Background Technology

[0002] With the continuous development of industrial automation and the increasing demands for energy efficiency, motor control technology has made significant progress. Permanent magnet materials are the core components of permanent magnet synchronous motors (PMSMs), and their performance directly affects the overall performance of the motor. Through doping, heat treatment, and other methods, the magnetic properties and stability of these materials have been further improved. Simultaneously, significant progress has been made in the research of non-rare-earth permanent magnet materials, making it possible to reduce the cost of PMSMs. The design of the motor structure also has a crucial impact on the performance of PMSMs. For example, optimizing the magnetic circuit design increases the motor's magnetic field strength and torque density; adopting novel cooling structures reduces the motor's temperature rise, improving its reliability and service life. Furthermore, some novel motor structures, such as dual-stator PMSMs and transverse flux PMSMs, have also been proposed.

[0003] Permanent magnet synchronous motors (PMSMs) are widely used in many fields, especially electric vehicles, due to their high efficiency, high power density, and excellent speed regulation performance. Since electric vehicles are direct passenger transport vehicles, the control of PMSMs needs to meet not only speed and output torque requirements but also other factors such as operational smoothness and safety. Summary of the Invention

[0004] One of the objectives of this invention is to provide a permanent magnet synchronous motor control system for electric vehicles, which comprehensively considers the vehicle's state and executes the corresponding motor drive strategy, thereby meeting the requirements for stability and safety during the operation of electric vehicles.

[0005] The present invention provides a permanent magnet synchronous motor control system for electric vehicles, comprising: a vehicle state analysis module, a control strategy determination module, and an execution module; The vehicle state analysis module is used to analyze the current state of the electric vehicle and obtain the analysis results; the control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state; and the execution module is used to execute the control strategy.

[0006] Preferably, the vehicle status analysis module performs the following operations: Acquire monitoring data from pressure sensors located at various detection points on the vehicle; Obtain vehicle driving parameter data; The driving parameter data and monitoring data are input into a pre-trained and converged analysis model to form a dataset corresponding to the analysis results.

[0007] Preferably, the detection locations include: the upper surface of the seat cushions of each car seat, the upper surface of the bottom of the interior of each car seat, the bottom of the trunk, and each suspension connection point.

[0008] Preferably, the driving parameters include one or more combinations of speed, acceleration, and steering wheel angle.

[0009] Preferably, the control strategy determination module performs the following operations: Using the dataset corresponding to the analysis results, retrieve the parameter set of the corresponding associated control strategy from the pre-configured strategy analysis library; Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

[0010] Preferably, the execution module includes control units configured for each motor; The control unit performs the following operations: Analyze the control strategy and determine the control parameters; The parameters of the pre-configured fuzzy PID control model are updated based on the control parameters.

[0011] Preferably, the fuzzy PID control model includes: a fuzzy controller and a PID controller; the fuzzy controller uses fuzzy control rules to correct the PID parameters of the PID controller in real time; The fuzzy controller performs the following operations: Obtain the deviation between the control target and the feedback quantity, and the change in deviation; Based on the deviation and the amount of deviation change, the pre-configured fuzzy control rule table is queried to determine the corresponding PID parameters.

[0012] Preferably, the permanent magnet synchronous motor control system applied to electric vehicles further includes: a road condition analysis module, used to analyze the current road conditions of the electric vehicle and obtain road condition data; The control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state, including: Feature extraction is performed on road condition data, and the corresponding strategy analysis library is retrieved based on the extracted feature parameters. Using the dataset corresponding to the analysis results, retrieve the parameter set of the corresponding associated control strategy from the strategy analysis library; Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

[0013] Preferably, the acquisition of road condition data includes: Based on the location data of electric vehicles, road condition configuration data is obtained from a pre-configured road condition map; Real-time road condition data is obtained through road condition data collection devices on electric vehicles; By comprehensively analyzing road condition configuration data and real-time road condition data, road condition data is obtained.

[0014] Preferably, the permanent magnet synchronous motor control system applied to electric vehicles further includes: a trigger holding module, used to analyze and judge the current road conditions and / or vehicle status to determine whether to enter strategy analysis; when strategy analysis is entered, the control strategy determination module works; otherwise, it does not work.

[0015] Preferably, the trigger holding module performs the following operations: Analyze the vehicle status to determine whether each trigger item meets the pre-configured trigger conditions; And / or, Arrange the feature parameters corresponding to the current road conditions in order to form a feature vector; Calculate the similarity between the feature vector corresponding to the current road condition and the feature vector corresponding to the road condition at the previous sampling time; the similarity calculation can be performed using a pre-similarity calculation method; When the similarity is less than or equal to the preset trigger threshold, trigger strategy analysis is initiated. And / or, Based on the risk scoring table corresponding to each trigger item of the vehicle status, the data of the trigger item is evaluated to obtain the first score value; Based on a pre-configured second evaluation table, determine the second score value corresponding to the similarity; When the sum of the first and second ratings exceeds a pre-configured rating threshold, strategy analysis is triggered. The triggering items include: speed, and / or, steering wheel rotation angle; the triggering conditions include: the difference between the speeds at adjacent sampling times is greater than a preset difference threshold, and / or, the steering wheel rotation angle is greater than or equal to a preset angle threshold.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a permanent magnet synchronous motor control system applied to an electric vehicle according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the fuzzy PID control model in an embodiment of the present invention. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] This invention provides a permanent magnet synchronous motor control system for electric vehicles, such as... Figure 1 As shown, it includes: a vehicle status analysis module, a control strategy determination module, and an execution module; The vehicle state analysis module is used to analyze the current state of the electric vehicle and obtain the analysis results; the control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state; and the execution module is used to execute the control strategy.

[0021] The vehicle status analysis module performs the following operations: Acquire monitoring data from pressure sensors located at various detection points on the vehicle; Obtain vehicle driving parameter data; Driving parameter data and monitoring data are input into a pre-trained and converged analysis model to form a dataset corresponding to the analysis results. This dataset includes data regions indicating the weight distribution at various locations of the electric vehicle, as well as data regions corresponding to various driving parameters, which are then filled with preset values. Specifically, the data regions indicating the weight distribution at various locations of the electric vehicle can be understood as finite element subdivisions of the electric vehicle from a top-down view perspective, obtaining individual finite element units. The relative positions of these finite element units correspond to the data in the dataset, i.e., one data point corresponds to one finite element unit. During finite element subdivision, a 3D model of the vehicle is constructed, and the boundaries of the 3D model and the boundaries of the vehicle's interior space are mapped onto the plane corresponding to the top-down view. The system first divides the interior space into fixed and variable regions based on the boundaries of the interior space. Then, it performs a second division based on the correspondence between the variable regions and the detection positions. The fixed regions are divided according to the pre-configured segmentation mesh. Based on the volume-to-mass ratio of each position corresponding to the 3D model, the initial values ​​of the inherent weight parameters of the finite element elements after the fixed region segmentation and the initial values ​​of the variable weight parameters of the finite element elements after the variable region segmentation are calculated. The variable values ​​of the variable finite element elements are obtained by processing the detection data of the detection positions through the analysis model. The sum of the initial values ​​and the variable values ​​is used as the weight parameters of the variable finite element elements. The detection locations include: the upper surface of each car seat cushion, the upper surface of the underside of the vehicle interior in front of each car seat, the bottom of the trunk, and each suspension connection point. The upper surface of each car seat cushion allows for the determination of passenger distribution and weight in the electric vehicle; the upper surface of the underside of the vehicle interior in front of each car seat assists in determining passenger distribution and weight; furthermore, it allows for monitoring the weight of items placed there when no passengers are present; the bottom of the trunk allows for monitoring the weight of objects inside the trunk; and the suspension connections clearly show the weight distribution to each tire. This configuration of detection locations enables a comprehensive analysis of the vehicle's weight distribution, facilitating better analysis of the control strategies for each motor. Since the weight borne by each tire's motor will differ, corresponding adjustments to the control strategies are necessary to ensure smooth operation and safety. The driving parameters include one or more of the following: speed, acceleration, and steering wheel angle. The steering wheel angle is the angle the driver needs to turn the steering wheel from its current position relative to its initial position (the car is moving straight). The control strategy determination module performs the following operations: Using the dataset corresponding to the analysis results, the corresponding control strategy parameter set is retrieved from the pre-configured strategy analysis library. The strategy analysis library is pre-configured, and the control strategy parameter set in the strategy analysis library is associated with the dataset corresponding to the analysis results one-to-one. Based on the control strategy retrieval parameter set corresponding to the retrieval parameters of each motor, the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library. The control strategy library contains pre-configured control strategies for various motors. The difference between each control strategy lies in the specific values ​​of the PID control parameters, which are: proportional (P), integral (I), and derivative (D). When configuring the control strategy library, a different retrieval parameter is configured for each control strategy to achieve the retrieval of the corresponding control strategy from the library. During retrieval, each retrieval parameter in the control strategy retrieval parameter set corresponds to a motor. The execution module includes the control unit configured for each motor; The control unit performs the following operations: The control strategy is parsed to determine the control parameters. The control strategy contains control parameters, and the parsing operation is to extract the data belonging to the control parameters from the control strategy. The parameters of the pre-configured fuzzy PID control model are updated based on the control parameters. These control parameters include: the PID parameters of the PID controller and / or the table number of the fuzzy control rule table. Among them, such as Figure 2As shown, the fuzzy PID control model includes a fuzzy controller and a PID controller; the fuzzy controller uses fuzzy control rules to correct the PID parameters of the PID controller in real time. The fuzzy controller performs the following operations: Obtain the deviation between the control target and the feedback quantity, and the change in deviation; Based on the deviation and the change in deviation, the pre-configured fuzzy control rule table is queried to determine the corresponding PID parameters. The PID parameters include: speed loop PID parameters P, I, and D; current loop PID parameters P, I, and D. Multiple fuzzy control rule tables can be configured, each with a table number, to facilitate updates to the fuzzy PID control model. Real-time correction of PID parameters using fuzzy control rules can significantly improve the control accuracy of a system. The fuzzy controller is the core component, primarily used to analyze feedback signals from sensors and output corresponding feedback control schemes to the actuators, thereby achieving feedback regulation of the controlled object. Feedback quantities are generated from parameters such as motor speed actually detected by sensors. This invention uses the easily computed triangular membership function as the fuzzy controller function. The input to the fuzzy controller is a definite quantity, so it needs to be fuzzified first to ensure the fuzzy quantity conforms to the universe of discourse. Assume the given area variable is... The range of values ​​for the fuzzy area variable is {-n, n}, and the quantization factor and scaling factor are determined according to the following formula.

[0022] After the given input is adjusted by fuzzy control and fuzzy control rules, inverse fuzzy operations are needed to obtain accurate quantities to control the permanent magnet synchronous motor. Using the center-of-gravity method for anti-fuzzy calculations can yield accurate outputs.

[0023] In the formula, It's about output clarity. It is the weight of each group of elements.

[0024] In one embodiment, a permanent magnet synchronous motor control system for electric vehicles includes: a vehicle state analysis module, a road condition analysis module, a control strategy determination module, and an execution module; The road condition analysis module is used to analyze the current road conditions of electric vehicles and obtain road condition data. The road condition data includes: the type of road, whether there are potholes in front of the vehicle, and the size of the potholes if they exist. The vehicle status analysis module performs the following operations: Acquire monitoring data from pressure sensors located at various detection points on the vehicle; Obtain vehicle driving parameter data; The driving parameter data and monitoring data are input into a pre-trained and converged analysis model to form a dataset corresponding to the analysis results.

[0025] The inspection locations include: the upper surface of the seat cushions of each car seat, the upper surface of the bottom of the interior in front of each car seat, the bottom of the trunk, and each suspension connection point.

[0026] The driving parameters include one or more of the following: speed, acceleration, and steering wheel angle. The steering wheel angle is the angle the driver needs to turn the steering wheel from its current position relative to its initial position (the car is moving straight). The control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state, including: The system extracts features from road condition data and retrieves the corresponding strategy analysis library based on the extracted feature parameters. The feature parameters include: parameters indicating the type of road, parameters indicating whether there are potholes in front of the vehicle, and parameters indicating the size of the pothole when it exists. The system stores multiple strategy analysis libraries and retrieves different strategy analysis libraries based on different feature parameters to achieve accurate and effective strategy analysis. Using the dataset corresponding to the analysis results, retrieve the corresponding parameter set of the associated control strategy from the strategy analysis library; the parameter set of the control strategy in the strategy analysis library is associated one-to-one with the dataset corresponding to the analysis results. Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

[0027] The acquisition of road condition data includes: Based on the electric vehicle's location data, road condition configuration data is obtained from a pre-configured road condition map. The location of the electric vehicle can be determined through the location data, and based on this, the road condition configuration data of the road corresponding to that location is retrieved from the road condition map. The road condition configuration data includes: road type, whether there are potholes ahead, the size and location of the potholes (relative to the vehicle). Real-time road condition data is obtained through real-time road condition acquisition devices for electric vehicles, including cameras. The real-time road condition data is obtained by analyzing the images captured by the cameras. The real-time road condition data includes road type, whether there are potholes ahead, the size and location of potholes, whether there are vehicles ahead, and the positional relationship between the vehicles ahead and the vehicle itself. Road condition data is obtained by comprehensively analyzing road condition configuration data and real-time road condition data. Generally, the road type is based on the road condition configuration data, while the presence and size of potholes are based on the real-time acquisition equipment. Because image acquisition may be affected by factors such as obstructed vision by vehicles ahead, the specific steps for comprehensive analysis are as follows: When the road condition configuration data indicates a pothole ahead, but the real-time road condition data indicates no pothole ahead, determine whether the vehicles in the real-time road condition data cover the location of the pothole indicated in the road condition configuration data. If they cover it, the pothole data in the road condition configuration data is used; if they do not cover it, the real-time road condition data is used. When the road condition configuration data indicates no pothole ahead, but the real-time road condition data indicates a pothole ahead, the real-time road condition data is used. Specifically, determining whether vehicles in the real-time road condition data cover the location of the pothole indicated in the road condition configuration data involves constructing a first vector indicating the location of the pothole in the road condition configuration data and a second vector indicating the positional relationship between the vehicle ahead and the current vehicle. When the angle between the first and second vectors is less than or equal to a preset angle, it can be determined as coverage.

[0028] In one embodiment, a permanent magnet synchronous motor control system for electric vehicles includes: a vehicle state analysis module, a trigger-hold module, a road condition analysis module, a control strategy determination module, and an execution module; The trigger-and-hold module analyzes and judges the current road conditions and / or vehicle status to determine whether to enter strategy analysis. Once strategy analysis is entered, the strategy determination module operates; otherwise, it does not. Frequent strategy analysis during the operation of an electric vehicle is undesirable, unnecessary, and extremely wasteful of analysis resources. Therefore, the trigger-and-hold module is used for triggering; if no strategy analysis is triggered, the strategy from the previous trigger analysis is retained. The vehicle status analysis module performs the following operations: Acquire monitoring data from pressure sensors located at various detection points on the vehicle; Obtain vehicle driving parameter data; The driving parameter data and monitoring data are input into a pre-trained and converged analysis model to form a dataset corresponding to the analysis results.

[0029] The inspection locations include: the upper surface of the seat cushions of each car seat, the upper surface of the bottom of the interior in front of each car seat, the bottom of the trunk, and each suspension connection point.

[0030] The driving parameters include one or more of the following: speed, acceleration, and steering wheel angle. The steering wheel angle is the angle the driver needs to turn the steering wheel from its current position relative to its initial position (the car is moving straight). The control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state, including: Feature extraction is performed on road condition data, and the corresponding strategy analysis library is retrieved based on the extracted feature parameters. Using the dataset corresponding to the analysis results, retrieve the parameter set of the corresponding associated control strategy from the strategy analysis library; Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

[0031] The trigger holding module performs the following operations: Analyze the vehicle status to determine whether each trigger item meets the pre-configured trigger conditions; And / or, Arrange the feature parameters corresponding to the current road conditions in order to form a feature vector; Calculate the similarity between the feature vector corresponding to the current road condition and the feature vector corresponding to the road condition at the previous sampling time; the similarity calculation can be performed using a pre-similarity calculation method; When the similarity is less than or equal to the preset trigger threshold, trigger strategy analysis is initiated. And / or, Based on the risk scoring table corresponding to each trigger item of the vehicle status, the data of the trigger item is evaluated to obtain the first score value; Based on a pre-configured second evaluation table, determine the second score value corresponding to the similarity; When the sum of the first and second ratings exceeds a pre-configured rating threshold, strategy analysis is triggered. The triggering items include: speed, and / or, steering wheel rotation angle; the triggering conditions include: the difference between the speeds at adjacent sampling times is greater than a preset difference threshold, and / or, the steering wheel rotation angle is greater than or equal to a preset angle threshold.

[0032] Furthermore, due to the delay in strategy analysis, to achieve a smooth transition of control between the strategy analysis results and the trigger time, the sum of the first and second score values ​​can be used as the trigger marker data. Using the marker data of this trigger and the marker data of the previous trigger, the pre-configured transition strategy table can be queried to determine the transition strategy for each motor during the transition period; that is, the fuzzy PID control model is updated according to the parameters indicated by the transition strategy.

[0033] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A permanent magnet synchronous motor control system for electric vehicles, characterized in that, include: Vehicle status analysis module, control strategy determination module, and execution module; The vehicle state analysis module is used to analyze the current state of the electric vehicle and obtain the analysis results; the control strategy determination module is used to determine the control strategy of each motor based on the analysis results of the current state. The execution module is used to execute control policies.

2. The permanent magnet synchronous motor control system for electric vehicles as described in claim 1, characterized in that, The vehicle status analysis module performs the following operations: Acquire monitoring data from pressure sensors located at various detection points on the vehicle; Obtain vehicle driving parameter data; The driving parameter data and monitoring data are input into a pre-trained and converged analysis model to form a dataset corresponding to the analysis results.

3. The permanent magnet synchronous motor control system for electric vehicles as described in claim 2, characterized in that, The inspection locations include: the upper surface of the seat cushions of each car seat, the upper surface of the bottom of the interior in front of each car seat, the bottom of the trunk, and each suspension connection point.

4. The permanent magnet synchronous motor control system for electric vehicles as described in claim 2, characterized in that, Driving parameters include one or more of the following: speed, acceleration, and steering wheel angle.

5. The permanent magnet synchronous motor control system for electric vehicles as described in claim 2, characterized in that, The control strategy determination module performs the following operations: Using the dataset corresponding to the analysis results, retrieve the parameter set of the corresponding associated control strategy from the pre-configured strategy analysis library; Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

6. The permanent magnet synchronous motor control system for electric vehicles as described in claim 1, characterized in that, The execution module includes the control unit configured for each motor; The control unit performs the following operations: Analyze the control strategy and determine the control parameters; The parameters of the pre-configured fuzzy PID control model are updated based on the control parameters.

7. The permanent magnet synchronous motor control system for electric vehicles as described in claim 6, characterized in that, The fuzzy PID control model includes a fuzzy controller and a PID controller; the fuzzy controller uses fuzzy control rules to correct the PID parameters of the PID controller in real time. The fuzzy controller performs the following operations: Obtain the deviation between the control target and the feedback quantity, and the change in deviation; Based on the deviation and the amount of deviation change, the pre-configured fuzzy control rule table is queried to determine the corresponding PID parameters.

8. The permanent magnet synchronous motor control system for electric vehicles as described in claim 1, characterized in that, Also includes: The road condition analysis module is used to analyze the current road conditions of electric vehicles and obtain road condition data; The control strategy determination module is used to determine the control strategy for each motor based on the analysis results of the current state, including: Feature extraction is performed on road condition data, and the corresponding strategy analysis library is retrieved based on the extracted feature parameters. Using the dataset corresponding to the analysis results, retrieve the parameter set of the corresponding associated control strategy from the strategy analysis library; Based on the control strategy, the parameter set corresponding to each motor is retrieved, and the corresponding control strategy for each motor is retrieved from the pre-configured control strategy library.

9. The permanent magnet synchronous motor control system for electric vehicles as described in claim 8, characterized in that, Traffic data acquisition includes: Based on the location data of electric vehicles, road condition configuration data is obtained from a pre-configured road condition map; Real-time road condition data is obtained through road condition data collection devices on electric vehicles; By comprehensively analyzing road condition configuration data and real-time road condition data, road condition data is obtained.

10. The permanent magnet synchronous motor control system for electric vehicles as described in claim 1, characterized in that, Also includes: The trigger-and-hold module is used to analyze and judge the current road conditions and / or vehicle status to determine whether to enter strategy analysis; once strategy analysis is entered, the control strategy determination module is activated. Otherwise, it won't work.

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