CAN (Controller Area Network) communication topology architecture for electronic mechanical braking

Abstract

The invention discloses an electronic mechanical braking CAN communication topology architecture which comprises a main controller, a redundant controller and four wheel end controllers, and the main controller and the redundant controller communicate with two of the wheel end controllers through two paths of different main and private CANs respectively. And the main controller and the redundant controller are respectively communicated with the other two wheel end controllers through the other two paths of different redundant private CANs. According to the CAN communication topology architecture for electronic mechanical braking, the main controller and the redundant controller are only connected with two wheel end controllers on one CAN, so that the communication problems of serious signal reflection, waveform distortion, unreasonable arrangement of terminal resistors and the like can be avoided; a multi-point failure scene is supported, and a better redundancy effect is formed; the communication stability of each path of private CAN can be guaranteed, and the reliability of an electronic mechanical braking system is improved.

Description

Technical Field

[0001] This invention relates to the field of electromechanical braking technology, and more specifically, to a CAN communication topology architecture for electromechanical braking. Background Technology

[0002] With the development of automotive technology, the performance requirements for braking systems are becoming increasingly stringent. Simultaneously, with the widespread adoption of driver assistance systems, the performance requirements for brake-by-wire are also rising. Currently, the mainstream braking system is hydraulic braking, which has a relatively long braking response time and makes it difficult to decouple the braking at each wheel. Besides the hydraulic master cylinder driving the brakes, an additional power assist structure is required, resulting in insufficient support for brake-by-wire.

[0003] Electromechanical Braking (EMB) is a completely decoupled braking system where the braking forces of each wheel are fully decoupled. EMB uses electrified actuators to replace traditional hydraulic or pneumatic brake actuators. The controller of an EMB system typically consists of a main controller, redundant controllers, and four wheel-end controllers. The communication topology refers to the connection methods and data transmission paths between the various components (such as ECUs, sensors, actuators, etc.) in the EMB system, forming a network structure. It determines how data is transmitted within the system and how coordination and control between components are achieved. Currently, the mainstream network for EMB systems is CAN / CANFD, and existing network topologies all involve the main or redundant controller being connected to all four wheel-end controllers. The CAN bus uses differential signals (CAN_H and CAN_L) for communication. A CAN bus network requires a 120Ω terminating resistor at each end of the bus. CAN FD is an enhanced and evolved version of CAN, increasing data bandwidth, but its physical medium and principle remain the same as CAN.

[0004] The current CAN communication topology of electromechanical braking has the following two problems: there are four remote nodes in the CAN communication of traditional electromechanical braking; and in traditional electromechanical braking, a short circuit between the main CAN and redundant CAN of a single wheel-end controller will cause the entire system to fail completely.

[0005] Therefore, there is an urgent need for a CAN communication topology architecture for electromechanical braking. Summary of the Invention

[0006] The purpose of this invention is to provide a CAN communication topology for electromechanical braking to solve the problems in the prior art. The main controller and redundant controller are connected to only two wheel-end controllers on one CAN bus, which can avoid communication problems such as severe signal reflection, waveform distortion, and unreasonable arrangement of terminating resistors.

[0007] This invention provides a CAN communication topology for electromechanical braking, comprising: a main controller, a redundant controller, and four wheel-end controllers. The main controller and the redundant controller communicate with two of the wheel-end controllers via two different main private CAN channels, and the main controller and the redundant controller communicate with the other two wheel-end controllers via two other different redundant private CAN channels.

[0008] In the CAN communication topology architecture for electromechanical braking described above, preferably, the main controller is used to send braking commands to each of the wheel-end controllers, and the redundant controller is used to send braking commands to each of the wheel-end controllers in the event of failure or degradation of the main controller.

[0009] In the CAN communication topology architecture of electromechanical braking described above, preferably, the main controller and the redundant controller each have at least two CAN transceivers.

[0010] In the CAN communication topology architecture of electromechanical braking described above, preferably, each wheel-end controller is provided with a terminating resistor with a resistance of 120 ohms.

[0011] In the CAN communication topology architecture of electromechanical braking described above, preferably, the main controller and the redundant controller communicate with two diagonally distributed wheel-end controllers through two different main private CAN channels, and the main controller and the redundant controller communicate with two other diagonally distributed wheel-end controllers through two other different redundant private CAN channels.

[0012] In the CAN communication topology architecture of electromechanical braking described above, preferably, the wheel-end controller includes a left front wheel-end controller, a right front wheel-end controller, a left rear wheel-end controller, and a right rear wheel-end controller.

[0013] In the CAN communication topology architecture of electromechanical braking described above, preferably, the main private CAN includes a first main CAN and a second main CAN, and the redundant private CAN includes a first redundant CAN and a second redundant CAN.

[0014] In the CAN communication topology architecture for electromechanical braking described above, preferably, the nodes on the first main CAN include the main controller, the left front wheel end controller, and the right rear wheel end controller; the nodes on the second main CAN include the main controller, the right front wheel end controller, and the left rear wheel end controller.

[0015] In the CAN communication topology architecture for electromechanical braking described above, preferably, the nodes on the first redundant CAN include the redundant controller, the left front wheel end controller, and the right rear wheel end controller; the nodes on the second redundant CAN are the redundant controller, the right front wheel end controller, and the left rear wheel end controller.

[0016] In the CAN communication topology architecture for electromechanical braking described above, preferably, the main controller includes at least one of a braking system controller, a chassis domain controller, a power chassis domain controller, and a zone controller, and the redundant controller includes a braking system auxiliary controller.

[0017] This invention provides a CAN communication topology architecture for electromechanical braking. The main controller and redundant controller are connected to only two wheel-end controllers on one CAN bus, which can avoid communication problems such as severe signal reflection, waveform distortion, and unreasonable placement of terminating resistors. It supports multi-point failure scenarios, forming a better redundancy effect. It can ensure the communication stability of each private CAN bus and improve the reliability of the electromechanical braking system. It is applicable to electric vehicles, hybrid vehicles and traditional fuel vehicles, and has a wide range of applications. Attached Figure Description

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0019] Figure 1 A block diagram of the CAN communication topology architecture of the main controller for electromechanical braking provided by the present invention;

[0020] Figure 2 A block diagram of the CAN communication topology architecture for the redundant controller of electromechanical braking provided by the present invention.

[0021] Explanation of reference numerals in the attached diagram: 1-Main controller, 2-Redundant controller, 3-Left front wheel controller, 4-Right front wheel controller, 5-Left rear wheel controller, 6-Right rear wheel controller, 7-First main CAN, 8-Second main CAN, 9-First redundant CAN, 10-Second redundant CAN. Detailed Implementation

[0022] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0023] The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as “including” or “contains” mean that the element preceding the term encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as “above” and “below” are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0024] In this disclosure, when a specific component is described as being located between a first component and a second component, an intermediary component may or may not be present between the specific component and the first or second component. When a specific component is described as connecting to other components, the specific component may be directly connected to the other components without having an intermediary component, or it may not be directly connected to the other components but may have an intermediary component.

[0025] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0026] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0027] One current CAN communication topology for electromechanical braking involves connecting four wheel-end controllers simultaneously to a single CAN network. This technology has three CAN communication channels, all in the same configuration. Another current CAN communication topology for electromechanical braking involves multiple wheel-end control units communicating with the chassis domain control unit via a high-speed bus. The drawback of both schemes is that while the electromechanical braking system (EMB) wheel-end controllers are located at the wheel end, the VCU / BCU1 / BCU2 in this technology are located in the passenger compartment. BCU stands for Brake Control Unit. Therefore, the communication topology effectively has four furthest nodes, leading to severe signal reflection, waveform distortion, and problems with the proper placement of terminating resistors.

[0028] Another current CAN communication topology for electromechanical braking involves placing the main controller at the front and rear of the vehicle. The drawback of this approach is that it restricts the installation location of the main controller and redundant controllers, which is detrimental to the overall vehicle layout. A variation of this approach uses a terminating resistor to create a physical remote terminal for one of the controllers; however, the controller is still actually located in the passenger compartment. This variation is a high-risk remedial measure and increases the risk of failure.

[0029] like Figure 1 and Figure 2 As shown, the CAN communication topology architecture for electromechanical braking provided in this embodiment includes: a main controller (MECU) 1, a redundant controller (RECU) 2, and four wheel-end controllers. The main controller and the redundant controller 2 communicate with two of the wheel-end controllers through two different main private CANs, and the main controller and the redundant controller 2 communicate with the other two wheel-end controllers through two other different redundant private CANs.

[0030] The main controller 1 is used to send braking commands to each of the wheel-end controllers, and the redundant controller 2 is used to send braking commands to each of the wheel-end controllers in the event of failure or degradation of the main controller 1. In one embodiment of the present invention, the main controller 1 includes at least one of a braking system controller, a chassis domain controller, a power chassis domain controller, and a zone controller, and the redundant controller 2 includes a braking system auxiliary controller. It should be noted that the present invention does not specifically limit the types of the main controller 1 and the redundant controller 2.

[0031] Furthermore, the main controller and the redundant controller 2 communicate with two diagonally distributed wheel-end controllers via two different main private CAN channels, and the main controller and the redundant controller 2 communicate with another two diagonally distributed wheel-end controllers via two other different redundant private CAN channels. The CAN communication topology of the electromechanical braking system of this invention is designed in an X-shape. This ensures that even in the event of multi-point failure (three out of four CAN channels fail, such as a short circuit), the electromechanical braking system can still operate with diagonally distributed wheel-end actuators. The longitudinal deceleration is reduced but still reaches 0.2g, and the vehicle body does not lose lateral control. This performance is superior to that of simultaneous operation of wheel-end actuators on the same side or coaxial operation.

[0032] Furthermore, the wheel-end controllers include a left front wheel-end controller (WCU-FL) 3, a right front wheel-end controller (WCU-FR) 4, a left rear wheel-end controller (WCU-RL) 5, and a right rear wheel-end controller (WCU-RR) 6. The master private CAN includes a first master CAN (MCAN1) 7 and a second master CAN (MCAN2) 8, and the redundant private CAN includes a first redundant CAN (RCAN1) 9 and a second redundant CAN (RCAN2) 10.

[0033] Specifically, the nodes on the first main CAN 7 include the main controller 1, the left front wheel controller 3, and the right rear wheel controller 6; the nodes on the second main CAN 8 include the main controller 1, the right front wheel controller 4, and the left rear wheel controller 6.

[0034] The nodes on the first redundant CAN 9 include the redundant controller 2, the left front wheel end controller 3, and the right rear wheel end controller 6; the nodes on the second redundant CAN 10 are the redundant controller 2, the right front wheel end controller 4, and the left rear wheel end controller 6.

[0035] Furthermore, both the main controller 1 and the redundant controller 2 have at least two CAN transceivers. Each wheel-end controller is equipped with a 120-ohm terminating resistor. For example... Figure 1 and Figure 2 As shown, each wheel-end controller is connected to four private CAN channels.

[0036] The CAN communication topology architecture for electromechanical braking provided in this invention connects the main controller and redundant controller to only two wheel-end controllers on one CAN bus, which avoids communication problems such as severe signal reflection, waveform distortion, and improper placement of terminating resistors; it supports multi-point failure scenarios, forming a better redundancy effect; it can ensure the communication stability of each private CAN bus, improving the reliability of the electromechanical braking system; it is applicable to electric vehicles, hybrid vehicles, and traditional fuel vehicles, and has a wide range of applications.

[0037] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0038] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A CAN communication topology architecture for electromechanical braking, characterized in that, The application relates to a vehicle control system comprising: a main controller and a redundant controller, which communicate with two of the four wheel end controllers via two different main private CANs, and which communicate with the other two of the four wheel end controllers via two different redundant private CANs.

2. The electromechanical braking CAN communication topology architecture of claim 1, wherein, The main controller is configured to send brake commands to the wheel end controllers, and the redundant controller is configured to send brake commands to the wheel end controllers in the event of failure or degradation of the main controller.

3. The electromechanical braking CAN communication topology architecture of claim 1, wherein, The main controller and the redundant controller each have at least two CAN transceivers.

4. The electromechanical braking CAN communication topology architecture of claim 1, wherein, Each of the wheel end controllers is provided with a terminal resistor having a resistance of 120 ohms.

5. The electromechanical braking CAN communication topology architecture of claim 1, wherein, The main controller and the redundant controller each communicate with two of the four wheel end controllers via two different main private CANs, and the main controller and the redundant controller each communicate with the other two of the four wheel end controllers via two different redundant private CANs.

6. The electromechanical braking CAN communication topology architecture of claim 5, wherein, The wheel end controllers comprise a left front wheel end controller, a right front wheel end controller, a left rear wheel end controller and a right rear wheel end controller.

7. The electromechanical braking CAN communication topology architecture of claim 6, wherein, The main private CANs comprise a first main CAN and a second main CAN, and the redundant private CANs comprise a first redundant CAN and a second redundant CAN.

8. The electromechanical braking CAN communication topology architecture of claim 7, wherein, The nodes on the first main CAN comprise the main controller, the left front wheel end controller and the right rear wheel end controller, and the nodes on the second main CAN comprise the main controller, the right front wheel end controller and the left rear wheel end controller.

9. The electromechanical braking CAN communication topology architecture of claim 7, wherein, The nodes on the first redundant CAN comprise the redundant controller, the left front wheel end controller and the right rear wheel end controller, and the nodes on the second redundant CAN comprise the redundant controller, the right front wheel end controller and the left rear wheel end controller.

10. The electromechanical braking CAN communication topology architecture of claim 1, wherein, The main controller comprises at least one of a brake system controller, a chassis domain controller, a power chassis domain controller and a zone controller, and the redundant controller comprises a brake system auxiliary controller.

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