CN118289082A

CN118289082A - Electronic power steering system and vehicle comprising same

Info

Publication number: CN118289082A
Application number: CN202410570884.8A
Authority: CN
Inventors: 张飞翔; 窦德海; 汪帅丽; 裴福兴; 郁邦国; 董涛涛; 杨坤
Original assignee: Zhejiang Geely Holding Group Co Ltd; Zhejiang Remote Commercial Vehicle R&D Co Ltd; Zhejiang Geely Remote New Energy Commercial Vehicle Group Co Ltd
Current assignee: Zhejiang Geely Holding Group Co Ltd; Zhejiang Remote Commercial Vehicle R&D Co Ltd; Zhejiang Geely Remote New Energy Commercial Vehicle Group Co Ltd
Priority date: 2024-05-09
Filing date: 2024-05-09
Publication date: 2024-07-05

Abstract

The application provides an electronic power steering system and a vehicle including the same. The electronic power steering system includes N subsystems. Each subsystem includes a controller, a drive circuit, and a six-phase motor. The controller includes a first controller and a second controller. The driving circuit comprises a first driving circuit and a second driving circuit. The first controller is connected with a first driving circuit, and the first driving circuit is connected with a three-phase winding of the six-phase motor. The second controller is connected with a second driving circuit, and the second driving circuit is connected with the other three-phase windings of the six-phase motor. The first controller is used for responding to the steering request signal and controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output torque. The second controller is used for responding to the steering request signal and controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output torque. The controllers of the N subsystems are connected in pairs. Each subsystem includes a first pathway and a second pathway. The first path comprises a first controller, a first driving circuit and three-phase windings of the six-phase motor. The second path comprises a second controller, a second driving circuit and the rest three-phase windings of the six-phase motor. When M (M < N1) paths of the N subsystems fail, the controller of the non-failed paths is used for: and controlling the three-phase winding output torque of the six-phase motor connected with the controller of the non-failure passage according to the steering request signal. The application can improve the safety.

Description

Electronic power steering system and vehicle comprising same

Technical Field

The application relates to the technical field of steering control of vehicles, in particular to an electronic power steering system and a vehicle comprising the same.

Background

With the development of automobiles towards electric control and intelligence, the development of automatic driving is faster and faster. The demands for functional safety for high-level autopilot have increased accordingly. The steering system of the automobile is used as a transverse actuating mechanism for automatic driving, and corresponding functional safety schemes are required to be adapted according to different levels of automatic driving standards so as to avoid the occurrence of functional failure of the steering of the automobile.

An electronic power steering system (EPS, electronic Power Steering) is a power steering system that directly relies on an electric motor to provide assist torque. On the basis of the traditional mechanical steering system, according to a torque signal on a steering wheel and a running speed signal of an automobile, an electronic control device is utilized to enable a motor to generate auxiliary power with corresponding magnitude and direction, so that a driver is assisted in steering operation. The electronic power-assisted steering system has been used for comprehensively replacing the traditional hydraulic power-assisted steering system with the advantages of light weight, high efficiency, energy conservation, environmental protection and the like, becomes standard of modern vehicles, is an important component of intelligent automobiles, and is also an indispensable part for high-order auxiliary driving and automatic driving.

For L2 level autopilot (assisted driving, vehicles can perform part of driving tasks such as automatic acceleration and deceleration, automatic steering, etc., but still require driver monitoring and ready take over), EPS usually adopts a non-redundant or partially redundant steering system architecture, and when a single point failure occurs in the system, the steering function will be lost. And the automatic driving is carried out at the level of L3 or above, the EPS is generally in a redundant structure, and at least 50% of steering assistance can be provided when single-point failure occurs, so that the automatic driving function is supported to realize safe side parking. However, when a two-point failure occurs, the EPS may not provide sufficient steering assistance, and the vehicle may run out of control.

Disclosure of Invention

The application provides an electronic power steering system and a vehicle comprising the same, which can improve the safety of the steering system when double-point failure occurs.

The application provides an electronic power-assisted steering system which is applied to a vehicle and comprises N subsystems, wherein N is a positive integer greater than or equal to 2; each subsystem comprises a controller, a driving circuit and a six-phase motor, wherein the controller comprises a first controller and a second controller, and the driving circuit comprises a first driving circuit and a second driving circuit; the first controller is connected with the first driving circuit, and the first driving circuit is connected with the three-phase winding of the six-phase motor; the second controller is connected with the second driving circuit, and the second driving circuit is connected with the other three-phase windings of the six-phase motor; the first controller is used for responding to a steering request signal and controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output torque, and the second controller is used for responding to the steering request signal and controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output torque;

The controllers of the N subsystems are connected in pairs; each of the subsystems includes a first pathway and a second pathway; the first path comprises the first controller, the first driving circuit and a three-phase winding of the six-phase motor; the second path comprises the second controller, the second driving circuit and the rest three-phase windings of the six-phase motor;

When M (1.ltoreq.M < N) paths of the N subsystems fail, the controller of the non-failed paths is configured to: and controlling the three-phase winding output torque of the six-phase motor connected with the controller of the non-failure passage according to the steering request signal.

Optionally, the first controller is configured to send the steering request signal to the second controller.

Optionally, the first controller is configured to determine 1/N of the steering request torque, and is configured to send 1/2N of the steering request torque to the second controller;

The first controller is used for controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output 1/2N of the steering request torque;

the second controller is used for controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output 1/2N of the steering request torque.

Alternatively to this, the method may comprise,

When M (1.ltoreq.M < N) paths of the N subsystems fail, the controller of the non-failed paths is configured to:

Determining the smaller value of 1/(2N-M) of the steering request torque and the maximum steering torque which can be output by the three-phase winding of the six-phase motor;

and controlling three-phase windings of the six-phase motor connected with the controller of the non-failed path to output the smaller value.

Optionally, when two of the paths of either of the subsystems fail, the first controller of the non-failed subsystem is configured to determine 1/(N-1) of the steering request torque, and to transmit 1/(2N-2) of the steering request torque to the second controller of the same subsystem.

Optionally, the electronic power steering system at least includes a first communication line and a second communication line, where the first communication line is connected to the first controller of the N subsystems, and is configured to transmit the steering request signal to the first controller; the second communication line is connected with the second controllers of the N subsystems and is used for transmitting the steering request signals to the second controllers.

Optionally, when the first communication line fails, the second controller is configured to receive the steering request signal through the second communication line, and send the steering request signal to the first controller.

Optionally, each of the subsystems includes a first CAN transceiver and a second CAN transceiver; the first controller is connected with the first communication line through the first CAN transceiver; the second controller is connected with the second communication line through the second CAN transceiver.

Optionally, each of the subsystems includes a first power source and a second power source; the first power supply is connected with the first controller and is used for supplying power to the first controller; the second power supply is connected with the second controller and is used for supplying power to the second controller.

The application also provides a vehicle, which comprises a whole vehicle controller and the electronic power-assisted steering system, wherein the electronic power-assisted steering system is in communication connection with the whole vehicle controller, and the whole vehicle controller is used for sending a steering request signal to the electronic power-assisted steering system.

The electronic power-assisted steering system at least comprises 2 subsystems, each subsystem comprises a controller, a driving circuit and a six-phase motor, the controller comprises a first controller and a second controller, and the driving circuit comprises a first driving circuit and a second driving circuit; the first controller is connected with a first driving circuit which is connected with a three-phase winding of the six-phase motor; the second controller is connected with a second driving circuit which is connected with the other three-phase windings of the six-phase motor; the first controller is used for responding to the steering request signal and controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output torque, and the second controller is used for responding to the steering request signal and controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output torque; the controllers of the N subsystems are connected in pairs; each subsystem includes a first pathway and a second pathway; the first channel comprises a first controller, a first driving circuit and a three-phase winding of a six-phase motor; the second path comprises a second controller, a second driving circuit and other three-phase windings of the six-phase motor; when M (M is less than or equal to 1) channels of the N subsystems are failed, the controller of the non-failed channel can acquire the information of the failed channel, and the three-phase winding output torque of the six-phase motor connected with the controller of the non-failed channel is controlled according to the steering request signal. When the electronic power steering system fails in a double-point manner, for example, two controllers of the same subsystem or different subsystems fail, at least the other two controllers can work normally, at least partial steering power can be provided, the vehicle can be ensured to stop by side, the driving safety of the vehicle is improved, and the requirement of high-level automatic driving can be met.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

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

Fig. 1 is a circuit block diagram of one embodiment of an electronic power steering system of the present application.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "plurality" means two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. The word "comprising" or "comprises", and the like, means that elements or items appearing before "comprising" or "comprising" are encompassed by the element or item recited after "comprising" or "comprising" and equivalents thereof, and that other elements or items are not excluded. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

The electronic power steering system of the embodiment of the application comprises N subsystems. Each subsystem includes a controller, a drive circuit, and a six-phase motor. The controller includes a first controller and a second controller. The driving circuit comprises a first driving circuit and a second driving circuit. The first controller is connected with a first driving circuit, and the first driving circuit is connected with a three-phase winding of the six-phase motor. The second controller is connected with a second driving circuit, and the second driving circuit is connected with the other three-phase windings of the six-phase motor. The first controller is used for responding to the steering request signal and controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output torque. The second controller is used for responding to the steering request signal and controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output torque. The controllers of the N subsystems are connected in pairs. Each subsystem includes a first pathway and a second pathway. The first path comprises a first controller, a first driving circuit and three-phase windings of the six-phase motor. The second path comprises a second controller, a second driving circuit and the rest three-phase windings of the six-phase motor. When M (M < N1) paths of the N subsystems fail, the controller of the non-failed paths is used for: and controlling the three-phase winding output torque of the six-phase motor connected with the controller of the non-failure passage according to the steering request signal. The application can improve the safety.

The application provides an electronic power steering system and a vehicle including the same. The electronic power steering system and the vehicle including the same of the present application will be described in detail below with reference to the accompanying drawings. The features of the examples and embodiments described below may be combined with each other without conflict.

The application provides a vehicle, which comprises a whole vehicle controller and an electronic power steering system. The electronic power steering system is in communication connection with the whole vehicle controller. In some embodiments, the overall vehicle controller is communicatively coupled to the electronic power steering system via a CAN bus. The whole vehicle controller is used for sending a steering request signal to the electronic power steering system. The steering request signal indicates that the vehicle requests steering torque provided by the electronic power steering system. In some embodiments, the whole vehicle controller collects data such as a vehicle speed signal, a whole vehicle ready signal, a vehicle corner signal and the like, determines a steering request torque through a preset program, and sends the steering request torque to the electronic power steering system by taking the steering request signal as a carrier. In other embodiments, the electronic power steering system includes a controller that receives a steering request signal from a vehicle controller including data such as a vehicle speed signal, a vehicle ready signal, a vehicle turn signal, etc., and that automatically determines a steering request torque indicated by the steering request signal.

Fig. 1 is a circuit block diagram of one embodiment of an electronic power steering system 10 of the present application. The electronic power steering system 10 is applied to a vehicle provided by the present application. As shown in fig. 1, the electronic power steering system 10 includes N subsystems 20, where N is a positive integer greater than or equal to 2.

Each subsystem 20 includes a controller 21, a drive circuit 22, and a six-phase motor 23. The controller 21 includes a first controller 211 and a second controller 212. The driving circuit 22 includes a first driving circuit 221 and a second driving circuit 222. The first controller 211 is connected to a first driving circuit 221, and the first driving circuit 221 is connected to the three-phase windings of the six-phase motor 23. The second controller 212 is connected to a second drive circuit 222, and the second drive circuit 222 is connected to the remaining three-phase windings of the six-phase motor 23. The first controller 211 is configured to control the first driving circuit 221 to drive the output torque of the three-phase winding connected thereto in response to the steering request signal. The second controller 212 is configured to control the second driving circuit 222 to drive the output torque of the three-phase winding connected thereto in response to the steering request signal. In some embodiments, the sum of the torques output by the six-phase motor 23 of the N subsystems 20 is equal to the steering request torque indicated by the steering request signal. In other embodiments, the sum of the torques output by the partial six-phase electric machines 23 of the N subsystems 20 is equal to the steering request torque indicated by the steering request signal.

In the embodiment shown in fig. 1, N is equal to 2, and the electronic power steering system 10 includes 2 subsystems 20, the subsystems 20 including a first subsystem 201 and a second subsystem 202.

The first subsystem 201 includes a first controller 211, a second controller 212, a first drive circuit 221, a second drive circuit 222, and a first six-phase motor 231. The second subsystem 202 includes a third controller 213, a fourth controller 214, a third drive circuit 223, a fourth drive circuit 224, and a second six-phase motor 232.

The first controller 211 is connected to a first driving circuit 221, and the first driving circuit 221 is connected to the three-phase windings of the first six-phase motor 231. The second controller 212 is connected to a second driving circuit 222, and the second driving circuit 222 is connected to the remaining three-phase windings of the first six-phase motor 231.

The third controller 213 is connected to a third driving circuit 223, and the third driving circuit 223 is connected to the three-phase winding of the second six-phase motor 232. The fourth controller 214 is connected to a fourth drive circuit 224, the fourth drive circuit 224 being connected to the remaining three-phase windings of the second six-phase motor 232.

The controllers 21 of the N subsystems 20 are connected in pairs. Each controller 21 is connected not only to the controllers 21 located in the same subsystem 20, but also to the controllers 21 located in different subsystems 20, so that each controller 21 can acquire the operating status signal of any other controller 21 to determine whether the other controller 21 has a fault. Each subsystem 20 includes a first pathway and a second pathway. The first path includes the first controller 211, the first driving circuit 221, and the three-phase windings of the six-phase motor 23. The second path includes the second controller 212, the second drive circuit 222, and the remaining three-phase windings of the six-phase motor 23. When M (1.ltoreq.M < N) paths of the N subsystems 20 fail, the controller 21 of the non-failed path is configured to: the three-phase winding output torque of the six-phase motor 23 connected to the controller 21 of the non-failed path is controlled according to the steering request signal.

When the electronic power assisting system 10 is operating normally, the four controllers 21 respectively control the drive circuits 22 connected thereto to drive the three-phase windings of the six-phase motor 23 to output torques, and the sum of the torques output by the six-phase motor 23 is equal to the steering request torque indicated by the steering request signal. The six-phase motor 23 may distribute torque equally or unequally.

When M paths fail, the controllers 21 of the paths that do not fail may acquire the operating states of the controllers 21 of the other paths, thereby determining which controllers 21 fail. The controller 21 of the non-failed path recalculates the allocated torque of the six-phase motor 23 of each path according to the steering request signal. In some embodiments, the controller 21 of the non-failed path controls the sum of the torque output from the three-phase windings of the six-phase motor 23 connected to the controller 21 of the non-failed path to be equal to the steering request torque indicated by the steering request signal. In this way, sufficient steering assistance may still be provided in the event of a failure of the electronic assistance system 10.

In some embodiments, the six-phase motor 23 equally distributes torque. The three-phase windings of the six-phase motor 23 output one-fourth of the steering request torque. When any element of the electric power steering system 10 fails, i.e., any controller 21 or drive circuit 22 or three-phase windings of the six-phase motor 23 fail, three-phase windings of the six-phase motor 23 that are not failed can remain outputting three-fourths of the steering request torque, so that the vehicle can go forward with the failure or stop sideways.

When any two components of the electric power steering system 10 fail, the three-phase windings of the six-phase motor 23 that are not failed can remain at least one-half of the output steering request torque so that the vehicle can be parked on the side in the event of a two-point failure.

When the electronic power steering system 10 fails in a double-point manner, for example, when two controllers 21 of the same subsystem 20 or different subsystems 20 fail, at least the other two controllers 21 can work normally, at least 50% of steering power can be provided, the vehicle can be ensured to stop at the side, the running safety of the vehicle is improved, and the requirement of high-level automatic driving can be met.

The first controller 211 is connected to the second controller 212, and the first controller 211 is configured to transmit a steering request signal to the second controller 212.

The first controller 211 is connected with the second controller 212, and the first controller 211 and the second controller 212 mutually send and receive check signals to determine whether the other party is in a normal working state. The controller 21 includes a transceiver for receiving signals. When the electronic power assist system 10 is operating properly, both the first controller 211 and the second controller 212 may receive the steering request signal. When the transceiver of any one of the controllers 21 fails, the non-failed controller 21 may transmit a steering request signal to the failed controller 21. For example, the second controller 212 fails, the steering request signal cannot be received, the first controller 211 acquires the state information of the second controller 212 through the collected check signal of the second controller 212, the first controller 211 determines that the second controller 212 fails, and sends the steering request signal to the second controller 212, and the second controller 212 continues to control the second driving circuit 222 to work. Thus, when any controller 21 in the same subsystem 20 fails to receive the signal, the subsystem 20 can still normally output the steering request torque, and the driving safety of the vehicle is improved.

In some embodiments, the first controller 211 is configured to determine 1/N of the steering request torque and is configured to send 1/2N of the steering request torque to the second controller 212. The first controller 211 is for controlling the first driving circuit 221 to drive 1/2N of the three-phase winding output steering request torque connected thereto. The second controller 212 is configured to control the second driving circuit 222 to drive 1/2N of the three-phase winding output steering request torque connected thereto.

The second controller 212 may or may not receive the steering request signal. After receiving the steering request signal, the first controller 211 transmits the torque to be output by the three-phase winding controlled by the second controller 212 to the second controller 212. The first controller 211 determines 1/N of the steering request torque and transmits 1/2N of the steering request torque to the second controller 212. Thus, the second controller 212 does not need to determine the steering request torque by itself, and when the calculation module of one of the first controller 211 and the second controller 212 fails, the steering request torque can be obtained from the other, so that the driving capability of the vehicle with faults is improved, and the safety is improved.

In the embodiment shown in fig. 1, the first subsystem 201 includes a first pathway and a second pathway. The first path includes the first controller 211, the first driving circuit 221, and the three-phase windings of the first six-phase motor 231. The second path includes the second controller 212, the second drive circuit 222, and the remaining three-phase windings of the first six-phase motor 231. The second subsystem 202 includes a third path and a fourth path. The third path includes the third controller 213, the third driving circuit 223, and the three-phase windings of the second six-phase motor 232. The fourth path includes the fourth controller 214, the fourth drive circuit 224, and the remaining three-phase windings of the second six-phase motor 232.

When M (1.ltoreq.M < N) paths of N subsystems fail, the controller 21 of the non-failed path is configured to:

determining the smaller of 1/(2N-M) of the steering request torque and the maximum steering torque that can be output by the three-phase windings of the six-phase motor 23;

The three-phase windings of the six-phase motor 23 connected to the controller 21 of the non-failed path are controlled to output the smaller value.

Ideally, the steering request torque is now provided by the common use of 2N-M paths that are not faulty, each path providing 1/(2N-M) of steering request torque. The controller 21 of the non-faulty pathway is configured to control the three-phase winding connected thereto to output torque as much as possible that satisfies the steering request torque without exceeding the maximum steering torque that the three-phase winding connected thereto can output. Therefore, under the condition of faults, the steering request torque can be provided as large as possible, and the steering assistance capability of the vehicle is ensured.

In some embodiments, m=1. When any one of the N sub-systems 20 fails, the controller 21 of the non-failed path is configured to: determining the smaller value of 1/(2N-1) of the steering request torque and the maximum steering torque that can be output by the three-phase windings of the six-phase motor 23; the three-phase windings of the six-phase motor 23 connected to the controller 21 of the non-failed path are controlled to output the smaller value. Therefore, under the condition of single-point failure fault, the steering request torque can be provided as large as possible, and the steering power assisting capability of the vehicle is ensured.

In other embodiments, m=2. When any two paths of the electric power steering system 10 fail, the controller 21 of the non-failed path is configured to: determining the smaller of 1/(2N-2) of the steering request torque and the maximum steering torque that can be output by the three-phase windings of the six-phase motor 23; the three-phase windings of the six-phase motor 23 connected to the controller 21 of the non-failed path are controlled to output the smaller value. Therefore, under the condition of double-point failure fault, the steering request torque is provided as large as possible, and the steering power assisting capability of the vehicle is ensured.

In some embodiments, when two paths of either subsystem 20 fail, the first controller 211 of the non-failed subsystem 20 is used to determine 1/(N-1) of the steering request torque and to send 1/(2N-2) of the steering request torque to the second controller 212 of the same subsystem 20.

When two paths fail and the two paths are located in the same subsystem 20, the remaining (2N-2) paths need to provide the steering request torque, and if each path equally distributes the steering request torque, each path that is not failed needs to provide 1/(2N-2) of the steering request torque. The first controller 211 and the second controller 212 may determine the torque value to be provided by each path by themselves, or the first controller 211 may determine 1/(N-1) of the steering request torque and send 1/(2N-2) of the steering request torque to the second controller 212 in the same subsystem 20. In other embodiments, the first controller 211 may also send 1/(2N-2) of the steering request torque to the second controller 212 at a different subsystem 20. Thus, when the calculation module of the partial controller 21 fails, a control signal can be obtained, and the path can still normally output torque, so that the safety of the vehicle is improved.

In some embodiments, the electronic power steering system 10 includes at least a first communication line 24 and a second communication line 25. The first communication line 24 is connected to the first controller 211 of the N subsystems 20 for transmitting a steering request signal to the first controller 211. The second communication line 25 is connected to the second controller 212 of the N sub-systems 20 for transmitting a steering request signal to the second controller 212.

In some embodiments, the second controller 212 is configured to receive the steering request signal via the second communication line 25 and send the steering request signal to the first controller 211 when the first communication line 24 fails. When the second communication line 25 fails, the first controller 211 is configured to send a steering request signal to the second controller 212.

The first communication line 24 and the second communication line 25 are redundant to each other. Both the first communication line 24 and the second communication line 25 may transmit a steering request signal. When the electronic power steering system 10 is operating normally, both the first communication line 24 and the second communication line 25 may be in operation, transmitting signals to the first controller 211 and the second controller 212, respectively. It is also possible that only the first communication line 24 is in operation, the first communication line 24 transmitting a signal to the first controller 211, the first controller 211 in turn transmitting a signal to the second controller 212. When one of the first communication line 24 and the second communication line 25 fails, the other may continue to transmit the steering request signal. For example, when the first communication line 24 fails, the second communication line 25 is in an operating state, and transmits a signal to the second controller 212, and the second controller 212 transmits a signal to the first controller 211, so that the traveling capability of the vehicle with the failure can be improved.

In some embodiments, each subsystem 20 includes a first CAN transceiver and a second CAN transceiver. The first controller 211 is connected to the first communication line 24 through a first CAN transceiver. The second controller 212 is connected to the second communication line 25 via a second CAN transceiver.

The first CAN transceiver and the second CAN transceiver are redundant to each other. Both the first CAN transceiver and the second CAN transceiver may transmit a steering request signal. When the electronic power steering system 10 is operating normally, both the first CAN transceiver and the second CAN transceiver may be in operation, transmitting signals to the first controller 211 and the second controller 212, respectively. It is also possible that only the first CAN transceiver is in operation, the first CAN transceiver transmits a signal to the first controller 211, and the first controller 211 transmits a signal to the second controller 212. When one of the first CAN transceiver and the second CAN transceiver fails, the other CAN continue to transmit the turn request signal. For example, when the first CAN transceiver fails, the second CAN transceiver is in an operating state, and transmits a signal to the second controller 212, and the second controller 212 sends a signal to the first controller 211, so that the driving capability of the vehicle with the failure CAN be improved.

In some embodiments, each subsystem 20 includes a first power source and a second power source. The first power supply is connected to the first controller 211 for supplying power to the first controller 211. The second power source is connected to the second controller 212 for powering the second controller 212. The first controller 211 and the second controller 212 are powered by different power sources, and when any one of the power sources fails, the other controller 21 is not affected, so that the ability of the vehicle to travel with a failure can be improved.

In the embodiment shown in FIG. 1, the electronic power steering system 10 includes a third power source, a fourth power source, a third CAN transceiver, and a fourth CAN transceiver (not shown). The third power supply is connected to the third controller 213. The fourth power supply is connected to the fourth controller 214. The third CAN transceiver connects the third controller 213 and the first communication line 24. The fourth CAN transceiver connects the fourth controller 214 and the second communication line 25. The first controller 211, the second controller 212, the third controller 213, and the fourth controller 214 are connected in pairs.

When all the elements of the electronic power steering system 10 are operating normally, the first controller 211 and the third controller 213 receive steering request signals from the first communication line 24 through the first CAN transceiver and the third CAN transceiver, respectively. After the first controller 211 and the third controller 213 verify the respective operating states, 1/2 of the steering request torque is calculated. The first controller 211 transmits 1/4 of the steering request torque to the second controller 212. The third controller 213 sends 1/4 of the steering request torque to the fourth controller 214. The first controller 211 and the second controller 212 together control the first six-phase motor 231. The third controller 213 and the fourth controller 214 together control the second six-phase motor 232. The three-phase windings of the first six-phase motor 231 and the second six-phase motor 232 output 1/4 of the steering request torque within the respective torque output capacities, respectively. The entire electric power steering system 10 can output torque according to the maximum torque output capability of the six-phase motor 23.

When the first controller 211 or the element in the same path as it fails, the second controller 212 and the fourth controller 214 receive the steering request signal from the second communication line 25 through the second CAN transceiver and the fourth CAN transceiver, respectively. After the second controller 212 and the fourth controller 214 verify the respective operation states, the second controller 212 calculates 1/3 of the steering request torque, and the fourth controller 214 calculates 2/3 of the steering request torque. The fourth controller 214 transmits 1/3 of the steering request torque to the third controller 213. The second controller 212, the third controller 213, and the fourth controller 214 control the three-phase windings connected thereto to output 1/3 of the steering request torque within the range of the torque capacity thereof, respectively. The entire electronic power steering system 10 is provided with 1/3 of the maximum torque output capacity of the six-phase motor 23.

When the first controller 211 and the third controller 213 are simultaneously failed, or when the path in which the first controller 211 is located and the path in which the third controller 213 is located are simultaneously failed, the second controller 212 and the fourth controller 214 receive the steering request signal from the second communication line 25 through the second CAN transceiver and the fourth CAN transceiver, respectively. After the second controller 212 and the fourth controller 214 verify the respective operation states, 1/2 of the steering request torque is calculated, and the three-phase windings connected thereto are controlled within the torque capacity range thereof, respectively, to output 1/2 of the steering request torque. The entire electronic power steering system 10 is provided with 1/2 of the maximum torque output capacity of the six-phase motor 23.

When the first controller 211 and the second controller 212 simultaneously fail, or when the path in which the first controller 211 and the path in which the second controller 212 are simultaneously fail, the third controller 213 receives a steering request signal from the first communication line 24 through the third CAN transceiver. After the third controller 213 verifies that the operation state of itself is correct, it calculates the steering request torque and sends 1/2 of the steering request torque to the fourth controller 214. The third controller 213 and the fourth controller 214 together control the second six-phase motor 232. The entire electronic power steering system 10 is provided with 1/2 of the maximum torque output capacity of the six-phase motor 23.

When the first controller 211 and the fourth controller 214 simultaneously fail, or when the path in which the first controller 211 and the path in which the fourth controller 214 are simultaneously fail, the second controller 212 receives a steering request signal from the second communication line 25 through the second CAN transceiver. The third controller 213 receives a steering request signal from the first communication line 24 through the third CAN transceiver. After the second controller 212 and the third controller 213 verify the respective operating states, 1/2 of the steering request torque is calculated, and the three-phase windings connected thereto are controlled within the torque capacity thereof, respectively, to output 1/2 of the steering request torque. The entire electronic power steering system 10 is provided with 1/2 of the maximum torque output capacity of the six-phase motor 23.

Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. An electronic power steering system applied to a vehicle is characterized by comprising N subsystems, wherein N is a positive integer greater than or equal to 2; each subsystem comprises a controller, a driving circuit and a six-phase motor, wherein the controller comprises a first controller and a second controller, and the driving circuit comprises a first driving circuit and a second driving circuit; the first controller is connected with the first driving circuit, and the first driving circuit is connected with the three-phase winding of the six-phase motor; the second controller is connected with the second driving circuit, and the second driving circuit is connected with the other three-phase windings of the six-phase motor; the first controller is used for responding to a steering request signal and controlling the first driving circuit to drive the three-phase winding connected with the first driving circuit to output torque, and the second controller is used for responding to the steering request signal and controlling the second driving circuit to drive the three-phase winding connected with the second driving circuit to output torque; the controllers of the N subsystems are connected in pairs; each of the subsystems includes a first pathway and a second pathway; the first path comprises the first controller, the first driving circuit and a three-phase winding of the six-phase motor; the second path comprises the second controller, the second driving circuit and the rest three-phase windings of the six-phase motor;

2. The electronic power steering system of claim 1, wherein the first controller is configured to send the steering request signal to the second controller.

3. The electronic power steering system of claim 2, wherein the first controller is configured to determine 1/N of the steering request torque and to send 1/2N of the steering request torque to the second controller;

4. The electronic power steering system of claim 1, wherein,

5. An electronic power steering system according to claim 1, wherein when both of the paths of either of the subsystems fail, the first controller of the subsystem that is not failed is configured to determine 1/(N-1) of the steering request torque, and is configured to send 1/(2N-2) of the steering request torque to the second controller of the same subsystem.

6. The electronic power steering system according to claim 1, comprising at least a first communication line and a second communication line, the first communication line being connected to the first controller of the N subsystems for transmitting the steering request signal to the first controller; the second communication line is connected with the second controllers of the N subsystems and is used for transmitting the steering request signals to the second controllers.

7. The electronic power steering system of claim 6, wherein the second controller is configured to receive the steering request signal via the second communication line and send the steering request signal to the first controller when the first communication line fails.

8. The electronic power steering system of claim 6, wherein each of said subsystems comprises a first CAN transceiver and a second CAN transceiver; the first controller is connected with the first communication line through the first CAN transceiver; the second controller is connected with the second communication line through the second CAN transceiver.

9. The electronic power steering system of claim 1, wherein each of said subsystems comprises a first power source and a second power source; the first power supply is connected with the first controller and is used for supplying power to the first controller; the second power supply is connected with the second controller and is used for supplying power to the second controller.

10. A vehicle, comprising a vehicle controller and an electronic power steering system according to any one of claims 1-9, wherein the electronic power steering system is in communication with the vehicle controller, and the vehicle controller is configured to send a steering request signal to the electronic power steering system.