A wire-controlled chassis system, its control method, and a control method for a chassis component

Abstract

A steer-by-wire chassis system, its control method, and a control method for a chassis component. The steer-by-wire chassis system includes a chassis domain control system and multiple chassis components. The chassis domain control system is used to obtain the position information of the chassis components and determine the chassis position of the chassis components in the chassis; obtain the vehicle body state information of the chassis components and judge whether the chassis components can execute control instructions. The chassis components include a wheel control system and a wheel operating system. The wheel control system is used to send the position information and the vehicle body state information to the chassis domain control system; under the trigger of a control instruction or a safety control instruction, control the wheel operating system to work. Since the chassis components have independent wheel control systems, after being connected to the chassis system, they can communicate control instructions with the chassis domain control system and transmit the position information and vehicle body state information of the chassis components, so as to achieve the effect of plug-and-play of the chassis components on the chassis system.

Description

Technical Field

[0001] The present invention relates to the technical field of chassis domain control, and particularly relates to a steer-by-wire chassis system, its control method, and a control method for chassis components. Background Art

[0002] With the rapid development of automotive electrification and intelligence, key components such as drive, brake, and steering are gradually being steer-by-wire. The steer-by-wire chassis system eliminates a large number of mechanical connection devices and auxiliary components such as hydraulic and pneumatic components. At the same time, it can also improve the energy utilization efficiency of the chassis, thereby increasing the driving range of new energy vehicles. The steer-by-wire chassis system generally consists of a steer-by-wire steering subsystem, a brake-by-wire subsystem, a drive-by-wire subsystem, and a suspension-by-wire subsystem, and uses signal lines to replace the original mechanical structure to transmit control instructions.

[0003] Currently, most steer-by-wire chassis systems adopt a distributed or centralized architecture. However, at the system level, they are mostly assembled from steer-by-wire components, and the components still play a major role in functional decision-making in this system. That is, component control mostly adopts the control method of the original chassis system. Separate functional components are responsible for separate functions. For example, the steer-by-wire steering system is only responsible for the decision-making and execution of the steering functions of the chassis, and the brake-by-wire system is only responsible for the decision-making and execution of braking functions. The two functions do not have coordinated control.

[0004] Existing steer-by-wire chassis systems can only function as plug-and-play components of the whole vehicle, and cannot yet achieve plug-and-play with the wheel area as a chassis system component. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is that the existing steer-by-wire chassis system cannot yet achieve plug-and-play with the wheel area as a chassis system component.

[0006] According to a first aspect, in one embodiment, a steer-by-wire chassis system is provided, including a chassis domain control system and a plurality of chassis components;

[0007] The chassis domain control system is used to obtain control instructions issued by the upper control unit corresponding to each chassis position; obtain the position information of the chassis components to determine the chassis position of the chassis components in the chassis; obtain the vehicle body state information of the chassis components, where the vehicle body state information is used to reflect the current operation parameters of the wheel operating system of the chassis components; and judge whether the chassis components can execute the control instructions according to the current operation parameters and preset safety thresholds;

[0008] If the chassis assembly can execute the control instruction, send the control instruction to the wheel control system of the chassis assembly; if the chassis assembly cannot execute the control instruction, send the safety control instruction corresponding to the control instruction to the wheel control system. The safety control instruction is set corresponding to a preset safety threshold, and an exception message is generated and sent to the upper control unit;

[0009] The chassis assembly includes a wheel control system and a wheel operating system. The wheel operating system includes at least one of a drive system, a steering system, a braking system, and a suspension system; each chassis assembly is detachably connected to the chassis, and the wheel control system is detachably electrically connected to the chassis domain control system through a cable. The chassis position, the control instruction, and the chassis assembly correspond to each other;

[0010] The wheel control system is used to send the position information and the vehicle body state information to the chassis domain control system; under the trigger of the control instruction or the safety control instruction, control the wheel operating system to work.

[0011] According to a second aspect, a control method of a by-wire chassis system is provided in an embodiment, including:

[0012] Obtain the control instructions issued by the upper control unit corresponding to each chassis position;

[0013] Obtain the vehicle body state information of the chassis assembly at the chassis position corresponding to the control instruction, and determine whether the chassis assembly can execute the control instruction;

[0014] If the chassis assembly can execute the control instruction, send the control instruction to the wheel control system of the chassis assembly; if the chassis assembly cannot execute the control instruction, send the safety control instruction corresponding to the control instruction to the wheel control system. The safety control instruction is set corresponding to a preset safety threshold, and an exception message is generated and sent to the upper control unit;

[0015] Control the wheel operating system to work according to the control instruction or the safety control instruction.

[0016] According to a third aspect, a control method of a chassis assembly is provided in an embodiment, including:

[0017] Send the position information and the vehicle body state information of the chassis assembly to the chassis domain control system, obtain the control instruction or the safety control instruction, and control the wheel operating system to work according to the control instruction or the safety control instruction;

[0018] Obtain the fault information issued by the redundant device, and under the trigger of the fault information, control the chassis assembly to enter the fault response mode and stop receiving the instructions issued by the chassis domain control system.

[0019] According to the by-wire chassis system, its control method, and the control method of the chassis components in the above embodiments, since the chassis components have independent wheel control systems, after being connected to the chassis system, they can communicate control instructions with the chassis domain control system, and transmit the position information of the chassis components and the body state information, so as to achieve the effect of plug-and-play of the chassis components on the chassis system. Brief Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a chassis component provided for an embodiment;

[0021] Figure 2 It is a schematic structural diagram of a by-wire chassis system provided for an embodiment;

[0022] Figure 3 It is a flowchart of a control method for a chassis component provided for an embodiment;

[0023] Figure 4 It is a flowchart of a control method for a by-wire chassis system provided for an embodiment.

[0024] Reference Numerals: 1 - Chassis Component; 101 - Wheel Control System; 102 - Wheel Operating System; 103 - Wheel; 2 - Chassis Domain Control System; 3 - Upper Control Unit; 4 - Redundant Device. Detailed Description of the Embodiments

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0026] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment and do not mean that they are necessary sequences, unless it is stated that a certain sequence must be followed.

[0027] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0028] In an embodiment of the present invention, on the one hand, a chassis component with independent control of the wheel area is used, and the execution requirements of the whole vehicle function are allocated through the chassis domain control system, and the chassis components of the wire-controlled chassis are completely decoupled to realize the chassis function. The corresponding chassis components (i.e., chassis components) are matched by means of private bus communication so that they can be directly installed and used on the wire-controlled chassis, thereby realizing plug-and-play of the chassis components. On the other hand, by setting a fault protection mode in the chassis component or setting a fault protection mode through a redundant device, when a fault is detected in the chassis domain control system, the control instructions issued by the chassis domain control system will no longer be received, but the control instructions issued by the upper-level control unit will be received instead, and in this mode, the chassis is guaranteed to be able to perform basic functions.

[0029] Embodiment 1:

[0030] Please refer to Figure 1 and Figure 2 This embodiment provides a chassis assembly 1 and a control method thereof, wherein the chassis assembly 1 includes a wheel control system 101, a wheel operating system 102 and a wheel 103. The wheel operating system 102 includes at least one of a drive system, a steering system, a brake system and a suspension system. The chassis assembly 1 is applied to a wire-controlled chassis system.

[0031] In this application, the chassis assembly 1 can be understood as an overall structure corresponding to a wheel area. The wheel control system 101 controls the operation of the wheel operating system 102 through a preset control program, and drives the wheel 103 through the wheel operating system 102 to perform functions such as braking, rotation, steering and suspension. When the chassis assembly 1 is actually used, it needs to be installed on the chassis. A conventional vehicle has four front and rear wheels. At this time, there are four corresponding chassis assemblies 1. After the chassis assembly 1 is installed on the chassis, it is connected to the chassis domain control system 2 (or chassis domain control system 2) on the chassis through a cable to receive control instructions delegated from the upper layer.

[0032] In practical applications, each chassis component 1 is connected to the chassis domain control system 2 via a cable, for example, through a private CAN-FD bus. The chassis has ports for connecting the chassis components 1. When the chassis components 1 are connected, the position information of the chassis components 1 can be identified through these position ports and the private CAN-FD bus. Alternatively, it can be achieved by the wheel control system 101 of the chassis component 1 sending messages to the chassis domain control system 2, and the messages can carry position information. That is to say, the chassis domain control system 2 can identify whether the chassis component 1 is the front left wheel, front right wheel, rear left wheel or right rear wheel (i.e., identify the chassis position), so as to enable the chassis domain control system 2 to send the instructions corresponding to the position to the wheel control system 101 of the corresponding chassis component 1.

[0033] In this embodiment, a plug-and-play chassis component 1 is provided. This component consists of a wheel operating system 102 and a wheel control system 101, and the sensor component is integrated in the subsystem of the wheel operating system 102, and the wheel operating system 102 converts the signal into a bus signal for transmission between each component and the chassis domain control system 2. In practical applications, the suspension system can be the axial adjustment component of this component, responsible for adjusting the axial height of this component. The drive system is provided with a driving torque by a servo motor as the power source of the component, and is responsible for converting the braking torque into energy recovery under low-speed and low-torque conditions. The braking system is responsible for the braking function at medium and high speeds and high torques. The steering system provides the steering torque of the component. In addition, the systems included in this component are only used for the function execution of this component, that is, the steering, braking, driving, suspension and other systems in the four sets of components used by one chassis are exactly the same.

[0034] Among them, the control instructions issued by the upper control unit 3 are corresponding to each chassis component 1, and the control instructions of the two chassis components 1 may be the same or different. For example, for the two front wheels, when braking, the control instructions corresponding to the braking of the two front wheels (the output value of the brake at this time) are the same. Another example is that when driving on a slope, the control instructions of the suspension system between the two front wheels may not be the same, and the differential rotation implementation method can also be adopted between the steering systems. Therefore, for each chassis component 1, in the total control instructions issued by the upper control unit 3 at one time, through the chassis domain control system 2 disassembling (or not disassembling), there can be a control instruction corresponding to each chassis component 1, or there can be a corresponding control instruction corresponding to a chassis position.

[0035] By establishing an independent wheel control system 101 for each wheel (chassis component 1), the control instructions issued by the upper control unit 3 can also be degraded for execution when necessary, so as to achieve basic functions such as uniform motion, acceleration, deceleration and braking in case of failure.

[0036] For the chassis component 1 of the entire by-wire chassis system, the components it contains are the same. During chassis integration, the position of chassis component 1 can be identified through specific messages of the private CAN-FD. When each chassis component 1 is installed, there will be a separate private CAN-F harness corresponding to the chassis domain control system 2. Through this harness, it receives the information for position identification to set its functional position in the chassis. The wheel control system 101 then converts the control instructions and control mode signals sent by the chassis domain control system 2, as well as different corresponding relationships map (two-dimensional table), into the instruction values that this chassis component 1 needs to respond to, and then transfers the corresponding instruction information to other components in the component. In this way, the plug-and-play of chassis component 1 on the by-wire chassis system can be achieved.

[0037] In practical applications, for the actual hardware structure, it may not be necessary to add a controller to implement the wheel control system 101. The function of this wheel control system 101 can be integrated into the controller of a certain executing component. Only an additional private CANFD channel is required to identify the position of this chassis component 1, thereby saving costs and harnesses. For example, the function of this wheel control system 101 can be integrated into the braking system, and at the same time, the response time of the braking function can also be improved.

[0038] Taking a four-wheel vehicle as an example, the four chassis components 1 are fixed on the chassis frames of different platforms in a manner that can be independently disassembled and connected. The two components of the front and rear wheels are redundant with each other. Based on the unity and plug-and-play effect of the chassis component 1, the vehicle can ensure that if 2 chassis components 1 can work properly, the chassis can guarantee its basic functions. The situations of chassis component 1 failure can be divided into two types. One is that 3 or more chassis components 1 fail simultaneously. Among them, 2 chassis components 1 fail and belong to the same side of the vehicle body. In this case, the chassis components 1 must be replaced. The other is that 2 or fewer chassis components 1 fail simultaneously. Because the four chassis components 1 are exactly the same, when a single-sided failure occurs, the rear-wheel chassis component 1 on one side can be directly replaced with the front-wheel on the failed side, and only the corresponding private CAN-FD channel needs to be installed to complete the switching of the control task of the chassis component 1. That is to say, at least two front wheels are used to achieve the basic functions.

[0039] Next, the specific process of its control method for the chassis component 1 will be elaborated, as Figure 3 shown, this control method includes normal working steps and fault working steps.

[0040] Among them, the normal working steps may include:

[0041] Step 101: The wheel control system 101 sends the position information of the chassis component 1 and the vehicle body status information to the chassis domain control system 2. Based on the plug-and-play function of the chassis component 1 provided in this application, in order to achieve this function, it is realized through Step 101.

[0042] Specifically, when the chassis component 1 is installed on the chassis, the wheel control system 101 can send the position information to the chassis domain control system 2 to identify the chassis position. Only then can the chassis domain control system 2 send the corresponding control instructions to the chassis component 1. And the wheel control system 101 continuously sends the vehicle body status information to the chassis domain control system 2, and the chassis domain control system 2 uses the vehicle body status information to determine whether the chassis component 1 can execute the current control instructions, that is, to determine whether the chassis component 1 is available. Thus, the plug-and-play effect of the chassis component 1 can be achieved.

[0043] Step 102: The wheel control system 101 obtains the control instruction or the safety control instruction, and controls the wheel operating system 102 to work according to the control instruction or the safety control instruction.

[0044] Another technical objective of this application is to prevent the situation where the entire vehicle system cannot work when the chassis domain control system 2 fails. Corresponding to the chassis component 1, this situation also needs to be optimized and improved. To address this problem, this application solves it by adding the redundant device 4. The redundant device 4 can detect in real time whether the chassis domain control system 2 fails, and immediately start the fault protection mechanism when a failure occurs. The specific fault protection mechanism can refer to the description in other embodiments. In this embodiment, only the content related to the chassis component 1 is described.

[0045] Among them, the fault working steps and the normal working steps are in a parallel relationship, and may include:

[0046] Step 103: The wheel control system 101 obtains the fault information sent by the redundant device 4. Under the trigger of the fault information, it controls the chassis component 1 to enter the fault response mode and stops receiving the instructions sent by the chassis domain control system 2.

[0047] Step 104: The wheel control system 101 obtains the control instruction sent by the redundant device 4 or directly obtains the control instruction sent by the upper control unit 3. Subsequently, Step 102 can be executed.

[0048] Specifically, the redundancy device 4 obtains the control instructions sent by the layer control unit, which can be processed and then sent to the chassis component 1, or directly forwarded to the chassis component 1 without processing. However, for the chassis component 1, when a failure occurs, safety is obviously the top priority. Therefore, the wheel control system 101 receives the control instructions and executes the control instructions in a degraded manner. This corresponding relationship of degraded processing can be preset. For example, when the control instruction is acceleration, only half of the original acceleration parameter is executed in the fault response mode. When performing degraded processing, it can also timely give the user an abnormal feedback effect. The user can timely view the abnormal signal on the central control panel to cope with the failure of the chassis domain control system 2.

[0049] On the one hand, the activation of the fault protection mechanism can be achieved through the redundancy device 4, and on the other hand, it can also be achieved through the wheel control system 101 of the chassis component 1.

[0050] In practical applications, the control method of the chassis component 1 may further include:

[0051] Step 105: Obtain the message sent by the chassis domain control system 2, detect whether the message transmission is in error or detect whether frames are lost during the message transmission process, or confirm the fault information through the diagnostic trouble code. If the message transmission is in error or frames are lost during the message transmission process or there is fault information, output a first fault signal. That is to say, the wheel control system 101 executes the corresponding program to detect whether the chassis domain control system 2 fails. After a failure occurs, the first fault signal is output correspondingly.

[0052] Step 106: Obtain the first fault signals output by other chassis components 1. If there are at least two first fault signals, determine that the chassis domain control system 2 is in a fault state and stop receiving the instructions sent by the chassis domain control system 2. Subsequently, step 104 can be executed.

[0053] That is to say, the fault protection mechanism of the redundancy device 4 can be transplanted into the wheel control system 101 of each chassis component 1. Considering safety, to avoid a wrong judgment by one wheel control system 101, if the wheel control system 101 is used as the trigger of the fault protection mechanism, at least two first fault signals need to trigger simultaneously to determine that the chassis domain control system 2 fails.

[0054] Embodiment 2:

[0055] As Figure 2 shown, this embodiment provides a by-wire chassis system and its control method. The by-wire chassis system includes a chassis domain control system 2 and multiple chassis components 1; this embodiment is described by taking a four-wheel vehicle as an example. In some practical applications, the by-wire chassis system may further include a redundancy device 4.

[0056] The chassis domain control system 2 is used to communicate with the upper control unit 3 and the chassis components 1 respectively, for example, through the CAN-FD bus. Specifically, the chassis domain control system 2 can have the following functions:

[0057] Function 1: Obtain the control instructions issued by the upper control unit 3 corresponding to each chassis position.

[0058] Function 2: Obtain the position information of the chassis components 1 and determine the chassis position of the chassis components 1 in the chassis.

[0059] Function 3: Obtain the vehicle body state information of the chassis components 1, where the vehicle body state information is used to reflect the current operation parameters of the wheel operating system 102 of the chassis components 1; according to the current operation parameters and the preset safety threshold, determine whether the chassis components 1 can execute the control instructions; among them, if the chassis components 1 can execute the control instructions, send the control instructions to the wheel control system 101 of the chassis components 1; if the chassis components 1 cannot execute the control instructions, send the safety control instructions corresponding to the control instructions to the wheel control system 101, the safety control instructions are set corresponding to the preset safety threshold, and generate abnormal information, and send the abnormal information to the upper control unit 3.

[0060] The chassis components 1 can be the chassis components 1 described in the first embodiment. The chassis components 1 include a wheel control system 101 and a wheel operating system 102. The wheel operating system 102 includes at least one of a drive system, a steering system, a braking system, and a suspension system; each chassis component 1 is detachably connected to the chassis, and the wheel control system 101 is detachably electrically connected to the chassis domain control system 2 through a cable. The chassis position, the control instructions, and the chassis components 1 correspond to each other.

[0061] The wheel control system 101 is used to send the position information and the vehicle body state information to the chassis domain control system 2; under the trigger of the control instructions or the safety control instructions, control the wheel operating system 102 to work.

[0062] The redundant device 4 is used to detect whether the chassis domain control system 2 fails. If the chassis domain control system 2 fails, obtain the control instructions and send them to the wheel control system 101, and send the fault information to the upper control unit 3 and the wheel control system 101.

[0063] Under the trigger of the fault information, the wheel control system 101 is further used to control the chassis components 1 to enter the fault response mode and stop receiving the instructions issued by the chassis domain control system 2; the fault response mode includes a four-wheel drive mode, a four-wheel braking mode, and a four-wheel steering mode.

[0064] In practical applications, the redundancy device 4 is used to obtain the messages sent by the chassis domain control system 2, detect whether there is an error in message transmission or whether frames are lost during message transmission, or confirm the fault information through diagnostic trouble codes. If there is an error in message transmission, frames are lost during message transmission, or there is fault information, it is determined that the chassis domain control system 2 is in a fault state.

[0065] For example, the redundancy device 4 can be implemented in the form of a gateway controller. That is to say, the actual execution of the redundancy device 4 can be achieved by installing a separate gateway controller on the original bus. In addition to the bus interface, this gateway controller is also configured with 5 private CAN-FD channels. By monitoring the messages of the chassis domain control system 2 on the bus, it mainly detects the checksum and rolling counter algorithms and DTC fault codes to determine whether the chassis domain control system 2 is faulty. At the same time, this gateway controller should be able to detect the private CAN-FD channels of the chassis domain control for the four-wheel control systems 101. When both the chassis domain control system 2 and the bus fail, the four chassis components 1 can be controlled through this gateway controller on the private CAN-FD channels.

[0066] In practical applications, the wheel control system 101 is also used to obtain the messages sent by the chassis domain control system 2, detect whether there is an error in message transmission or whether frames are lost during message transmission, or confirm the fault information through diagnostic trouble codes. If there is an error in message transmission, frames are lost during message transmission, or there is fault information, a first fault signal is output; if there are at least two first fault signals, it is determined that the chassis domain control system 2 is in a fault state.

[0067] For example, in the normal working mode, the chassis component 1 receives control instructions from the chassis domain control system 2, and the instruction information includes: expected driving torque, expected braking torque, expected steering angle, and expected roll angle. In this mode, the main function of the wheel control system 101 is to convert, in combination with the characteristics of the corresponding mode, into the requirements that should be executed by the corresponding individual wheel 103 and transmit them to the corresponding sub-operation system. Therefore, the sub-operation system in the component can directly respond to the instructions according to the corresponding map (such as a two-dimensional table) after receiving the above instruction information.

[0068] In the fault response mode, the chassis assembly 1 can directly receive control instructions from the upper control unit 3. Since the chassis assemblies 1 communicate via a bus, the corresponding control instructions in this mode are as follows: Determine whether the control instruction belongs to the acceleration mode, deceleration mode, or constant speed mode, and start the drive or brake subsystem response according to the converted value of the actual instruction. In this mode, although the steering is four-wheel steering, the front-wheel steering is the main one, and the rear wheels only assist in steering in the case of large steering angles. The steering component motor of the front wheels can directly drive the front-wheel assembly according to the angle to complete the steering operation. Specifically, in the fault response mode, the processing of control instructions is also preset for specific vehicles and is not unique.

[0069] In the normal working mode, the chassis domain control system 2 controls the chassis assembly 1 by transmitting signals through the CAN-FD bus. After each wheel is installed with the assembly, a redundant communication channel, the private CAN-FD, also needs to be connected. In the normal mode, this channel only transmits the chassis position identification signal, that is, it is determined whether the chassis assembly 1 is performing tasks in the left front, right front, left rear, or right rear wheel area through this signal. After receiving this signal frame, the corresponding map is set. If the private CAN-FD bus is not installed, the chassis assembly 1 is set according to the signal before the last power-off. In this mode, the chassis assembly 1 is in a degraded mode but can still provide at least 50% of its performance.

[0070] The following elaborates on the specific process of the control method for the by-wire chassis system, as Figure 4 shown, this control method has the following steps:

[0071] Instruction acquisition step: The chassis domain control system 2 acquires the control instructions issued by the upper control unit 3 corresponding to each chassis position. The format of this control instruction is not restricted and should at least include the target steering angle, target vehicle speed, or target acceleration. The remaining instructions not included can be set by the chassis domain control system 2 itself.

[0072] Specifically, the upper control unit 3 generates an original control instruction according to the user's operation. The original control instruction needs to be processed and split into control instructions corresponding to each wheel 103. Each subsystem such as the suspension system of each wheel 103 has corresponding control instructions. The decomposition of the control instructions can be executed by the upper control system, or by the chassis domain control system 2, and if necessary, by the wheel control system 101. Generally, it is queried through a two-dimensional table and generated one by one corresponding to the user's operation. Specifically, it can be determined according to the actual situation of the vehicle. How the user's operation corresponds to the control instructions of the final wheel 103 is not the focus of this application and will not be elaborated here.

[0073] Instruction processing steps: The chassis domain control system 2 obtains the vehicle body state information of the chassis component 1 at the chassis position corresponding to the control instruction, and determines whether the chassis component 1 can execute the control instruction.

[0074] Among them, if the chassis component 1 can execute the control instruction, the chassis domain control system 2 sends the control instruction to the wheel control system 101 of the chassis component 1; if the chassis component 1 cannot execute the control instruction, the chassis domain control system 2 sends a safety control instruction corresponding to the control instruction to the wheel control system 101. The safety control instruction is set corresponding to a preset safety threshold, and an exception message is generated and sent to the upper control unit 3. The safety control instruction and the safety threshold can also be implemented through a predetermined two-dimensional table. For different abnormal situations, corresponding safety control instructions can be adopted.

[0075] Specifically, the chassis domain control system 2 receives the vehicle body state information from the chassis component 1. The vehicle body state information includes: actual steering angle, actual vehicle speed, XYZ three-axis acceleration, actual height of each chassis component 1 from the vehicle body, etc. According to the vehicle body state information and the safety threshold table set by calibration for different vehicle models and platforms, it is determined whether the control instruction can be executed. If it exceeds its own execution conditions, it will be executed according to a safety value below the safety threshold, and this information will be fed back to the upper control unit 3 of the autonomous driving. If the upper control instruction is within the safety range, the command will be executed according to the optimal response execution mode of the chassis. For example, when a single front tire gets stuck in a slippery road surface, for the two drive components corresponding to the front wheels, turning on the differential mode can better provide driving force for the chassis. Another example is when parking, the four wheels entering the in-situ steering mode can better and faster execute the parking function.

[0076] Instruction execution steps: The wheel control system 101 controls the wheel operating system 102 to work according to the control instruction or the safety control instruction.

[0077] Fault handling steps: The redundant device 4 detects whether the chassis domain control system 2 fails. If the chassis domain control system 2 fails, the redundant device 4 obtains the control instruction and sends it to the wheel control system 101, and sends the fault information to the upper control unit 3 and the wheel control system 101.

[0078] Specifically, the redundant device 4 obtains the message sent by the chassis domain control system 2, detects whether the message transmission is in error or detects whether there is a frame loss during the message transmission process, or confirms the fault information through the diagnostic fault code. If the message transmission is in error, there is a frame loss during the message transmission process, or there is fault information, it is determined that the chassis domain control system 2 is in a fault state.

[0079] For example, if the message transmission fails twice or more, it is determined that the chassis domain control system 2 is in a fault state; if 10 or more frames are lost during the message transmission process, it is determined that the chassis domain control system 2 is in a fault state; if there is a diagnostic trouble code, it is determined that the chassis domain control system 2 is in a fault state.

[0080] Fault handling steps: The redundant device 4 controls the chassis component 1 to enter the fault response mode and sends a control instruction to the wheel control system 101. The fault response mode includes four-wheel drive mode, four-wheel braking mode, and four-wheel steering mode. At this time, the four chassis components 1 are in the fault response mode, and the four wheels 103 can participate in the operations of driving, braking, and steering using the same or preset control instructions. In this fault response mode, the corresponding relationship with the original control instruction can also be implemented by querying a two-dimensional table. Specifically, it can be processed by the redundant device 4 or the wheel control system 101.

[0081] For example, during steering, two front wheels can perform the steering operation, and the rotational speeds of the two front wheels are the same, without using complex functions such as differential steering. During braking, the braking force of each wheel can be the same. During driving, the driving force of each wheel is the same. The main idea is that when the chassis is in a fault, the wheel control system controls in a relatively fixed manner, and the same control instructions are used between two or four wheels to reduce the operation complexity and ensure operation safety.

[0082] In the fault response mode, the chassis component 1 can directly receive the control instruction from the automatic upper control unit 3 and directly respond to the control instruction through the interactive communication between the wheel control systems 101.

[0083] Embodiment 3:

[0084] Taking the steering function requirement during automatic parking as an example, this embodiment further illustrates the control method of the by-wire chassis system.

[0085] When the automatic driving upper control unit 3 sends a steering demand instruction to the chassis domain control system 2, the chassis domain control system 2 simultaneously and real-time detects the chassis state signal. According to the steering demand, it determines which mode to use for the steering execution. For example, the automatic driving upper control unit 3 gives an instruction that the steering demand is applied to the automatic parking function, or in the case where only the steering demand instruction is given at the upper layer, the chassis domain control system 2 determines that the four-wheel in-place steering mode should be used according to the actual steering angle, the required steering angle, and the lateral acceleration signal. In this mode, the component achieves a 90° in-place steering or the front wheels execute 80% and the rear wheels execute 20% in the reverse direction to complete the steering demand. It should be noted that the 90° and the execution ratios of the front and rear wheels are only example numbers here, and the actual parameters need to be calibrated in the actual controller before confirmation.

[0086] After confirming the steering mode and steering demand allocation, it is also necessary to perform stability control based on the chassis and then perform secondary allocation of the demand. That is, if the vehicle is in a stationary state or a low-speed state at this time, and the four-wheel steering demand and steering demand will not cause the chassis to lose stability, the steering demand can be allocated to each wheel control system 101. If this steering demand will generate an unexpected steering angle or cause the chassis to lose stability at this time, then the execution cannot be carried out according to the demand in this mode. Instead, the steering mode is switched, and the steering operation is performed when the chassis is stable according to the actual steering angle and steering demand trend.

[0087] When the wheel control system 101 receives the steering mode and demand instructions from the chassis domain control system 2, it corresponds to the steering torque demand of the executing components according to the internally calibrated map. The position of the wheel control system 101 is different, and the steering torque corresponding to the internal steering demand is also different. For example, the front wheels and the rear wheels may require different steering torques under the same steering demand, which is jointly determined by different steering modes and calibrated maps.

[0088] When the upper-level control unit 3 of the autonomous driving sends a steering demand instruction to the chassis domain control system 2, at this time, the redundant device 4 detects the state of the chassis domain control system 2. When the signal interaction is abnormal, it can trigger each chassis component 1 to switch to the fault protection mode, that is, directly receive the control instruction from the upper-level control unit 3 of the autonomous driving.

[0089] After the chassis component 1 confirms the failure of the chassis domain control system 2, it will directly receive the control instruction from the upper-level control unit 3 of the autonomous driving. At the same time, because it is in the fault protection mode, the chassis component 1 can only ensure the realization of the basic functions of the chassis driving, convert the steering demand into the torque demand of the steering components. In this mode, the front-wheel steering is the main steering execution, so the chassis component 1 of the front wheels performs the steering operation according to its torque demand, and the rear wheels do not perform the steering operation. When the steering demand is too large, the components of the rear wheels will also provide a part of the steering torque for auxiliary steering to make the steering response more sensitive. The determination of the size of the steering demand is obtained through calibration according to different steering angles and steering accelerations.

[0090] Those skilled in the art can understand that all or part of the functions of the various methods in the above embodiments can be implemented in a hardware manner or in a computer program manner. When all or part of the functions in the above embodiments are implemented in a computer program manner, the program can be stored in a computer-readable storage medium. The storage medium can include: read-only memory, random access memory, magnetic disk, optical disk, hard disk, etc. The above functions can be realized by a computer executing the program. For example, the program is stored in the memory of the device, and when the processor executes the program in the memory, the above all or part of the functions can be realized. In addition, when all or part of the functions in the above embodiments are implemented in a computer program manner, the program can also be stored in a storage medium such as a server, another computer, magnetic disk, optical disk, flash drive or mobile hard disk, and saved to the memory of the local device by downloading or copying, or the system of the local device is updated. When the processor executes the program in the memory, all or part of the functions in the above embodiments can be realized.

[0091] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art of the present invention, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A steer-by-wire chassis system, characterized in that, It includes a chassis domain control system and multiple chassis components; The chassis domain control system is used to obtain the control instructions sent by the upper control unit corresponding to each chassis position; obtain the position information of the chassis components to determine the positions of the chassis components in the chassis; obtain the vehicle body state information of the chassis components, and the vehicle body state information is used to reflect the current operation parameters of the wheel operating system of the chassis components; According to the current operation parameters and the preset safety threshold, determine whether the chassis components can execute the control instructions; If the chassis components can execute the control instructions, send the control instructions to the wheel control systems of the chassis components; if the chassis components cannot execute the control instructions, send the safety control instructions corresponding to the control instructions to the wheel control systems. The safety control instructions are set corresponding to the preset safety threshold, and generate abnormal information, and send the abnormal information to the upper control unit; The chassis components include wheel control systems and wheel operating systems, and the wheel operating systems include at least one of a drive system, a steering system, a braking system, and a suspension system; each chassis component is detachably connected to the chassis, and the wheel control systems are detachably electrically connected to the chassis domain control system through cables, and the chassis positions, control instructions, and chassis components correspond to each other; The wheel control systems are used to send the position information and the vehicle body state information to the chassis domain control system; under the trigger of the control instructions or the safety control instructions, control the wheel operating systems to work.

2. The steer-by-wire chassis system according to claim 1, characterized in that The drive-by-wire chassis system further includes a redundancy device; The redundancy device is used to detect whether the chassis domain control system fails. If the chassis domain control system fails, obtain the control instructions and send them to the wheel control systems, and send the fault information to the upper control unit and the wheel control systems; Under the trigger of the fault information, the wheel control systems are further used to control the chassis components to enter a fault response mode and stop receiving the instructions sent by the chassis domain control system; the fault response modes include four-wheel drive mode, four-wheel braking mode, and four-wheel steering mode.

3. The steer-by-wire chassis system according to claim 2, wherein, The redundancy device is used to obtain the messages sent by the chassis domain control system, detect whether the message transmission is in error or detect whether frames are lost during the message transmission process or confirm the fault information through diagnostic trouble codes. If the message transmission is in error or frames are lost during the message transmission process or there is fault information, determine that the chassis domain control system is in a fault state.

4. The steer-by-wire chassis system according to claim 1, characterized in that, The wheel control systems are further used to obtain the messages sent by the chassis domain control system, detect whether the message transmission is in error or detect whether frames are lost during the message transmission process or confirm the fault information through diagnostic trouble codes. If the message transmission is in error or frames are lost during the message transmission process or there is fault information, output a first fault signal; If there are at least two first fault signals, determine that the chassis domain control system is in a fault state.

5. A control method for a steer-by-wire chassis system, characterized in that, Using the drive-by-wire chassis system according to any one of claims 1-4, the method includes: Obtain the control instructions sent by the upper control unit corresponding to each chassis position; Obtain the vehicle body status information of the chassis components at the chassis position corresponding to the control instruction, and determine whether the chassis components can execute the control instruction; If the chassis components can execute the control instruction, send the control instruction to the wheel control system of the chassis components; if the chassis components cannot execute the control instruction, send a safety control instruction corresponding to the control instruction to the wheel control system, the safety control instruction is set corresponding to a preset safety threshold, and generate an exception message, and send the exception message to the upper control unit; Control the wheel operating system to work according to the control instruction or the safety control instruction.

6. The control method according to claim 5, wherein, The control method further includes: Detect whether the chassis domain control system fails. If the chassis domain control system fails, obtain the control instruction and send it to the wheel control system, and send the failure information to the upper control unit and the wheel control system; Control the chassis components to enter a failure response mode, and the failure response mode includes four-wheel drive mode, four-wheel braking mode, and four-wheel steering mode.

7. The control method according to claim 6, wherein Detecting whether the chassis domain control system fails includes: Obtain the message sent by the chassis domain control system, detect whether the message transmission is in error or detect whether frames are lost during the message transmission process, or confirm the failure information through diagnostic trouble codes. If the message transmission is in error or frames are lost during the message transmission process or there is failure information, determine that the chassis domain control system is in a failure state.

8. The control method according to claim 7, characterized in that, If the message transmission is in error or frames are lost during the message transmission process or there is failure information, determining that the chassis domain control system is in a failure state includes: If the message transmission is in error two or more times, determine that the chassis domain control system is in a failure state; If 10 or more frames are continuously lost during the message transmission process, determine that the chassis domain control system is in a failure state; If there is failure information, determine that the chassis domain control system is in a failure state.

9. A control method for a chassis assembly, characterized in that, Adopt the drive-by-wire chassis system as described in any one of claims 1-4, and the method includes: Send the position information and vehicle body status information of the chassis components to the chassis domain control system, obtain a control instruction or a safety control instruction, and control the wheel operating system to work according to the control instruction or the safety control instruction; Obtain the failure information sent by the redundant device, and under the trigger of the failure information, control the chassis components to enter a failure response mode and stop receiving the instructions sent by the chassis domain control system.

10. The control method according to claim 9, characterized in that, It further includes: Obtain the message sent by the chassis domain control system, detect whether the message transmission is in error or detect whether frames are lost during the message transmission process, or confirm the failure information through diagnostic trouble codes. If the message transmission is in error or frames are lost during the message transmission process or there is failure information, output a first failure signal; Obtain the first failure signals output by other said chassis components. If there are at least two first failure signals, determine that the chassis domain control system is in a failure state and stop receiving the instructions sent by the chassis domain control system.

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