A coaxial fault response method and system for a four-wheel independent drive system

Abstract

The application discloses a coaxial fault response method and system of a four-wheel independent driving system, and comprises the following steps: using double chips to build an electric driving control module respectively to realize 6-way current control; adopting SPI bus communication between the double chips of the electric driving control system to formulate a special protocol to realize emergency fault response; adopting double communication interfaces to access vehicle control commands; establishing a master-slave differential control mechanism to allow a control difference of a slave to exist with the master as a reference; establishing an emergency fault response mechanism, and a single driving fault in coaxial control needs another control unit to be quickly adjusted; an upper layer establishes a front-rear axle driving backup and fault response mechanism, and another axle needs to quickly take over power output after a single axle fault occurs. The application has the beneficial effects that the method can effectively shorten the transmission and response time of coaxial control faults.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of four-wheel independent drive, in particular to a coaxial fault response method and system of four-wheel independent drive system. BACKGROUND

[0002] In recent years, the driving technology of the automobile has been constantly updated and improved, in order to make the electric vehicle more safe and stable, and the driving power more powerful, many electric vehicles begin to adopt the system mode of four-wheel independent drive. SUMMARY

[0003] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0004] In view of the above existing problems, the present application is proposed.

[0005] Therefore, one of the technical problems solved by the present application is to provide a coaxial fault response method of four-wheel independent drive system, which can effectively shorten the transmission and response time of coaxial control fault.

[0006] To solve the above technical problems, the present application provides the following technical scheme: a double-chip is used to build an electric drive control system to realize 6-way current control; in the electric drive control system, an emergency fault response mechanism is established by using SPI bus communication to formulate a special protocol; a double communication interface is used to access the vehicle control command, and a master-slave differential control mechanism is established to allow the slave to exist control difference with the master as the reference; an emergency fault response mechanism is established, and a single drive fault in coaxial control needs another control unit to adjust quickly; a front and rear axle drive backup and fault response mechanism is established in the upper layer, and another axle needs to take over the power output quickly after a single axle fault occurs.

[0007] As a preferred scheme of the coaxial fault response method of the four-wheel independent drive system, the double-motor control system is built by using a fast failure mode, which has the function of heteronuclear check, a historical database is accessed in the double-chip control system, the database is a stored fault data, and when the drive system works, the running data is transmitted to the historical database for fault matching, and the matching principle is:

[0008] IF A THEN B(G)

[0009] Wherein: A is real-time data, B is fault result, G is fault determination interval, the determination interval needs to be set according to the actual fault occurrence, when any chip output data fails, the fast failure mode is started, and another non-fault chip is used to ensure system operation.

[0010] As a preferred scheme of the coaxial fault response method of the four-wheel independent drive system, the emergency fault response comprises guaranteeing through the SPI bus and a private protocol.

[0011] As a preferred scheme of the coaxial fault response method of the four-wheel independent drive system, the control of the electronic differential at the response end comprises the following steps: using the right wheel control target as a comparison reference value; collecting real-time rotation speed data of the left and right wheels; and establishing a rotation speed torque closed loop based on the right wheel control according to a current control required wheel speed difference value of the whole vehicle.

[0012] As a preferred scheme of the coaxial fault response method of the four-wheel independent drive system, the emergency fault response mechanism further comprises the following steps: collecting emergency fault information of the double electric drive; reducing the torque of the non-fault equipment; detecting the double-wheel rotation speed to ensure that the rotation speed at the end of the reduced torque wheel is consistent with that of the fault wheel; and uploading the fault and the processed torque.

[0013] As a preferred scheme of the coaxial fault response method of the four-wheel independent drive system, the power transfer further comprises the following steps: detecting the fault state of the two shafts; classifying the fault shaft state and sending a 0 torque request to the fault wheel; and taking over the power vacancy for the normal state power shaft.

[0014] Another technical problem solved by the present application is to provide a coaxial fault response system of a four-wheel independent drive system, so that the above method can be realized based on the system.

[0015] To solve the above technical problems, the present application provides the following technical scheme: a coaxial fault response system of a four-wheel independent drive system, comprising: an electric drive control module capable of realizing current control; a fault response module for fault monitoring; and an interface module for accessing the whole vehicle control command.

[0016] As a preferred scheme of the coaxial fault response system of the four-wheel independent drive system, wherein: the fault response module comprises a historical fault database for storing historical data of the four-wheel independent drive system; a detection unit is connected to the historical fault database, and real-time data is matched with fault data in the historical fault database to find faults; and a quick failure unit is connected to the interface module, and the quick failure unit sends a fault signal to the interface module to immediately stop the operation of the related line when the detection unit finds a fault.

[0017] The method provided by the application can effectively shorten the transmission and response time of coaxial control faults and improve the working efficiency of the four-wheel independent drive system. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0019] Figure 1 The overall flowchart of the coaxial fault response method of the four-wheel independent drive system according to the first embodiment of the application;

[0020] Figure 2 The overall structure diagram of the coaxial fault response system of the four-wheel independent drive system according to the second embodiment of the application. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application will be described in detail below with reference to the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the application.

[0022] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, but the application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the scope of the application. Therefore, the application is not limited to the specific embodiments disclosed below.

[0023] Secondly, the "one embodiment" or "an embodiment" referred to herein means a specific feature, structure, characteristic, or combination of features and characteristics described herein that can be included in at least one implementation of the present application. The various appearances of "in one embodiment" or "in an embodiment" in the specification do not all refer to the same embodiment, although they can.

[0024] The present application is described in detail in conjunction with the schematic drawings, and in the detailed description of the embodiments of the present application, the sectional view of the device structure is partially enlarged without the general proportion for the convenience of illustration, and the schematic drawings are only examples, which should not limit the scope of protection of the present application. In addition, three-dimensional spatial dimensions including length, width and depth should be included in actual production.

[0025] Meanwhile, in the description of the present application, it should be noted that the terms "upper, lower, inner and outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first, second or third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] Unless otherwise specifically defined and limited in the present application, the terms "mounting, connecting, connection" should be broadly understood, for example: it can be fixed connection, detachable connection or integral connection; it can also be mechanical connection, electrical connection or direct connection, it can also be indirectly connected through intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Embodiment 1

[0028] Reference Figure 1 For the first embodiment of the present application, the embodiment provides a coaxial fault response method of a four-wheel independent drive system, comprising the following steps,

[0029] S1: using double chips to build an electric drive control system respectively to realize 6-way current control. It should be noted that,

[0030] Since single electric drive cannot realize 6-way current control, it is necessary to realize 6-way current control through double electric drive, and the control of permanent magnet motor needs to control 6-way switching devices to complete the inversion of power from direct current to alternating current. Based on the importance of the power system in the whole vehicle, double chips are selected to build a double motor control system in the chip building, so that it has the function of heteronuclear verification.

[0031] Further, the dual-motor control system is built, which includes using the fast failure mode to make the system have the function of checking the different cores, accessing the historical database in the dual-chip built control system, the database being the stored fault data, transmitting the running data to the historical database for fault matching when the driving system works, and the matching principle being:

[0032] IF A THEN B(G)

[0033] Wherein: A is real-time data, B is a fault result, G is a fault determination interval, and the determination interval needs to be set according to the actual fault occurrence, when the output data of any chip fails, the fast failure mode is started to use another chip without failure to ensure system operation.

[0034] S2: The dual-chip of the electric drive control system uses SPI bus communication to formulate a special protocol to realize emergency fault response. It should be noted that,

[0035] The emergency fault response is guaranteed by SPI bus and private protocol. Since the matching of the coaxial driving system in four-wheel independent driving requires high real-time requirement, for us-level fault response, timely communication is needed as a guarantee, therefore, SPI bus and private protocol are used to complete fault notification and establish an emergency fault guarantee mechanism based on it.

[0036] S3: Dual communication interfaces are used to access the vehicle control command. It should be noted that,

[0037] The control command of the vehicle for the coaxial dual-motor controller needs to use two communication channels to receive complete control commands, and the use of dual-channel communication backup can prevent the control of a single motor drive from being out of control due to communication channel failure.

[0038] S4: Establish a master-slave differential control mechanism, and allow the slave to have a control difference based on the master control. It should be noted that,

[0039] Specifically, the electronic differential control in the response end includes the following steps,

[0040] S4-1: Use the right wheel control target as the comparison reference value;

[0041] S4-2: Collect real-time speed data of the left and right wheels;

[0042] S4-3: According to the current control requirement wheel speed difference of the vehicle, establish a speed and torque closed loop based on the right wheel control.

[0043] S5: Establish an emergency fault response mechanism, and the single drive fault in coaxial control needs to be quickly adjusted by another control unit;

[0044] Specifically, the emergency fault response mechanism further comprises the following steps,

[0045] S5-1: Collecting emergency fault information of the double electric drive;

[0046] S5-2: Reducing torque of the non-fault device;

[0047] S5-3: Detecting double-wheel rotating speed, and ensuring that the rotating speed of the reduced-torque wheel is consistent with that of the fault wheel;

[0048] S5-4: Uploading fault and processed torque.

[0049] S6: The upper layer establishes a front and rear axle drive backup and fault response mechanism, and another axle needs to quickly take over power output after a single axle fault. It should be noted that,

[0050] Specifically, the power transfer further comprises the following steps,

[0051] S6-1: Detecting the fault state of the two axles;

[0052] S6-2: Classifying the fault axle state, and sending a 0-torque request to the fault wheel;

[0053] S6-3: Normal state power axle, taking over the power vacancy.

[0054] In order to verify the technical effects adopted in the method, the embodiment selects a traditional fault response method and the method for comparison test, compares the test results by scientific means, and verifies the real effects of the method. The traditional fault response method analyzes the timeliness of the combined device according to the analysis result, and schedules the combined device.

[0055] In order to verify the beneficial effects of the present application, a four-wheel independent drive system, a controller and a fault detection device are selected for simulation experiments of two methods, and the two methods are divided into three groups for fault experiments, wherein 20 fault problems are selected for test in each group, the response time of the two methods to the fault problems and the influence of the fault problems on the system work are calculated respectively, the experimental results of the two methods are simulated by using PCL simulation software, and the experimental results are shown in Table 1 as follows:

[0056] Table 1: Comparison of experimental results.

[0057]

[0058] As shown in Table 1, the average reaction time of the application to the fault is between 50-65 ms, while the reaction time of the traditional fault response method is about 70 ms. The average reaction time of the application is significantly less than that of the traditional method. In addition, when a fault occurs, the working system of the traditional fault response method needs to stop running, while the application can maintain normal operation of the system when responding to the fault due to the use of dual channels for data transmission. Therefore, the application is more practical.

[0059] Embodiment 2

[0060] Referring to Figure 2 the schematic diagram, the schematic diagram is a whole structure schematic diagram of a coaxial fault response system of a four-wheel independent drive system proposed by the embodiment, and the coaxial fault response method of the four-wheel independent drive system proposed by the above embodiment can be realized by relying on the system. The system comprises an electric drive control module 100, a fault response module 200 and an interface module 300. The electric drive control module 100 can realize current control. The fault response module 200 is used for fault monitoring. The interface module 300 is used for access of vehicle control commands.

[0061] Further, the fault response module 200 comprises a historical fault database 201 used for storing historical data of faults of the four-wheel independent drive system, a detection unit 202 connected to the historical fault database 201, which matches real-time data with fault data in the historical fault database 201 to find faults, and a quick failure unit 203 connected to the interface module 300, which sends a fault signal to the interface module 300 to immediately stop the operation of related lines when the detection unit 202 finds a fault.

[0062] The electric drive control module 100 takes the right wheel in the four-wheel independent drive system as a reference value to control the difference in rotational speed of the left and right wheels. Since the system has dual communication channels, the quick failure unit 203 can also stop the equipment in the fault channel according to the fault information sent by the interface module 300 to ensure the overall operation of the system.

[0063] It should be appreciated that embodiments of the present application can be realized by computer hardware, a combination of hardware and software, or by computer instructions stored on a non-transitory computer-readable storage medium. The methods can be implemented in a computer program using standard programming techniques— including non-transitory computer-readable storage media configured with a computer program to implement the methods in which the storage media so configured causes a computer to operate in a specific and predefined manner— according to the methods described in the detailed embodiments and the accompanying drawings. Each program can be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the programs can be implemented in assembly or machine language, if desired. In any case, the language can be a compiled or interpreted language. Also, the programs can be able to operate on programmable electronic devices having thereon a computer program wrapped in a suitably programmed application-specific integrated circuit.

[0064] Further, the operations of the processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The processes described herein (or variations and / or combinations thereof) can be performed under the control of one or more computer systems configured with executable instructions (e.g., computer programs, one or more computer programs, or one or more applications) to perform the processes, by hardware, or combinations thereof. Computer programs include machine instructions that can be executed by one or more processors.

[0065] Further, the methods can be implemented in any suitable type of computing platform operably connected to, including but not limited to, a personal computer, a mini-computer, a mainframe, a workstation, a network or distributed computing environment, a stand-alone or integrated computer platform, or in communication with a charged particle tool or other imaging device, and the like. Aspects of the present application can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated to the computing platform, such as a hard disk, an optical read and / or write storage medium, RAM, ROM, and the like, such that it can be read by a programmable computer to configure and operate the computer to perform the processes described herein. Further, the machine-readable code, or portions thereof, can be transmitted over wired or wireless networks. The present application described herein includes these and other different types of non-transitory computer-readable storage media when such media include instructions or programs that implement the steps described above in conjunction with a microprocessor or other data processor. The present application also includes the computer itself when programmed according to the methods and techniques described herein. The computer programs are able to apply to input data to perform the functions described herein, thereby transforming the input data to generate output data that is stored to non-volatile memory. The output information can also be applied to one or more output devices, such as a display. In the preferred embodiments of the present application, the transformed data represents physical and tangible objects, including specific visual depictions of physical and tangible objects produced on a display.

[0066] As used in this application, the terms "component," "module," "system" and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution and a component can be localized, partially and / or entirely, in one computer or distributed between two or more computers. Also, these components can execute from various computer-readable media having various data structures stored thereon. The components can communicate by way of local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems via the signal).

[0067] It should be noted that the above-mentioned embodiments are only used to illustrate but not to limit the technical solutions of the present application, and although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalent replaced without departing from the spirit and scope of the technical solutions of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A coaxial fault response method for a four-wheel independent drive system, characterized by: It comprises the following steps, The double-chip is used to build the electric drive control system respectively to realize 6-way current control, wherein the electric drive control system is built, the system has the function of heteronuclear check by using the fast failure mode, the historical database is accessed in the double-chip built control system, the database is the stored fault data, when the drive system works, the running data is transmitted to the historical database for fault matching, the matching principle is: IF A THEN B (G) Wherein: A is real-time data, B is fault result, G is fault determination interval, the determination interval needs to be set according to the actual fault occurrence, when the output data of any chip fails, the fast failure mode is started to ensure the system operation by using another chip without failure; In the electric drive control system, the SPI bus communication is used to formulate a special protocol to establish an emergency fault response mechanism, wherein the emergency fault response includes guaranteeing through the SPI bus and private protocol; The double communication interface is used to access the vehicle control command, and the master-slave differential control mechanism is established, taking the master control as the reference to allow the control difference of the slave to exist, wherein the electronic differential control in the response end comprises the following steps, The right wheel control target is used as the comparison reference value; The real-time speed data of the left and right wheels is collected; According to the current control requirement wheel speed difference of the vehicle, the speed torque closed loop based on the right wheel control is established; The emergency fault response mechanism is established, and the single drive fault in the coaxial control needs another control unit to adjust quickly, wherein the emergency fault response mechanism further comprises the following steps, The emergency fault information of the double electric drive is collected; The non-fault equipment reduces the torque; The double-wheel speed is detected to ensure that the speed of the reduced torque wheel is consistent with the fault wheel; The fault and the processed torque are uploaded; The upper layer establishes the front and rear axle drive backup and fault response mechanism, and another axle needs to quickly take over the power output after a single axle fault, wherein the power transfer further comprises the following steps, The fault state of the two axles is detected; The fault axle state is classified, and a 0 torque request is sent to the fault wheel; The normal state power axle takes over the power vacancy.

2. A coaxial failure response system for a four-wheel independent drive system, applying the method of claim 1, characterized in that: It comprises, The electric drive control module (100) can realize current control; The fault response module (200) is used for fault monitoring; The interface module (300) is used for accessing the vehicle control command.

3. The on-axis failure response system for a four-wheel independent drive system of claim 2, wherein: The fault response module (200) comprises, The historical fault database (201) is used for storing the historical data of the four-wheel independent drive system when the fault occurs; The detection unit (202) is connected to the historical fault database (201), and the real-time data is matched with the fault data in the historical fault database (201) to find the fault; The fast failure unit (203) is connected to the interface module (300), when the detection unit (202) finds the fault, the fast failure unit (203) sends a fault signal to the interface module (300) to immediately stop the related line operation.

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