Steering ratio switching method, steering ratio switching device, and vehicle

Abstract

The application relates to a steering ratio switching method, a steering ratio switching device and a vehicle. The steering ratio switching method is applied to a steer-by-wire system and comprises the following steps: obtaining a user instruction for switching a steering ratio; obtaining a running state of the vehicle; forming a switching instruction according to the running state and the user instruction; and switching the steering ratio to a value matched with the user instruction according to the switching instruction. The steering ratio switching method can consider various states of vehicle running, and a switching instruction is formed in combination with the running state and the user instruction, so that the driving influence on the driver during the steering ratio switching process is reduced, the driving experience of the driver is more quiet and stable, and therefore the safety and stability of the steering ratio switching method are improved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a steering ratio switching method, a steering ratio switching device, and a vehicle. Background Technology

[0002] Steering ratio is the ratio of the steering wheel's turning angle to the wheel's turning angle. With the same wheel turning angle, a higher steering ratio requires the steering wheel to be turned more, while a lower steering ratio requires less turning.

[0003] When a car is stationary, traveling at low speeds, or with a large steering angle, drivers expect the steering system to provide a small steering ratio. This allows for efficient changes in the vehicle's direction with fewer steering wheel turns, reducing the driver's steering burden. Conversely, when a car is traveling at high speeds or with a small steering angle, drivers expect the steering system to provide a large steering ratio. This prevents even slight changes in steering wheel angle from causing the vehicle to steer, thus enhancing driving stability.

[0004] Therefore, the need for variable vehicle steering ratio arises. Summary of the Invention

[0005] This application provides a steering ratio switching method, a steering ratio switching device, and a vehicle to address some or all of the shortcomings in the related art.

[0006] The first aspect of this application provides a steering ratio switching method applied to a steer-by-wire system, comprising:

[0007] Obtain the user command for switching steering ratio;

[0008] Obtain the driving status of the vehicle;

[0009] Determine whether the driving state meets the switching conditions;

[0010] If so, a switching instruction is generated based on the user instruction;

[0011] According to the switching instruction, the steering ratio is switched to a value that matches the user instruction.

[0012] Furthermore, the driving state includes at least one of steering ratio, speed, steering angle, lateral acceleration, or steering wheel angle.

[0013] Furthermore, the switching condition is: the steering wheel angle of the vehicle changes and the steering wheel rotation passes through zero point.

[0014] Furthermore, the speed at which the steering wheel angle changes is less than a preset speed.

[0015] Furthermore, the range of change in the steering wheel angle is greater than or equal to 2° and less than or equal to 8°.

[0016] Further, the step of generating a switching instruction based on the user instruction is as follows:

[0017] An instant switching instruction is generated based on the user's instructions;

[0018] Wherein, the step of switching the steering ratio to a value matching the user instruction according to the switching instruction means: switching the steering ratio to a value matching the user instruction immediately according to the instant switching instruction.

[0019] Furthermore, after determining whether the driving state meets the switching conditions, the method further includes:

[0020] If not, a delayed switching instruction is generated based on the user instruction;

[0021] Wherein, after generating the delayed switching instruction according to the user instruction, the method includes:

[0022] Obtain the driving status of the vehicle;

[0023] Determine whether the driving state meets the delay switching condition;

[0024] If so, the steering ratio is switched to a value matching the user instruction according to the delay switching instruction.

[0025] Furthermore, the switching condition is: the steering angle is less than a preset angle value.

[0026] Furthermore, the preset angle value includes a first preset angle value and a second preset angle value, and the first preset angle value is less than the second preset angle value;

[0027] Wherein, when the vehicle speed is greater than the speed preset value, the angle preset value is the first angle preset value; when the vehicle speed is less than or equal to the speed preset value, the angle preset value is the second angle preset value.

[0028] Furthermore, the switching condition is at least one of the following:

[0029] The steering angle is less than a first preset angle value, and the lateral acceleration is less than an acceleration preset value;

[0030] The steering angle is less than the second angle preset value, and the lateral acceleration is less than the acceleration preset value.

[0031] Furthermore, the delay switching condition is: the steering angle is less than the preset angle value and the duration is greater than or equal to the preset time.

[0032] Furthermore, after determining whether the driving state meets the delay switching condition, the method further includes:

[0033] If so, determine whether the direction of steering wheel rotation is in the same direction as the target angle position;

[0034] If so, the steering ratio is quickly switched to a value matching the user command according to the delay switching instruction; otherwise, the steering ratio is slowly switched to a value matching the user command according to the delay switching instruction.

[0035] Furthermore, after switching the steering ratio to a value matching the user instruction according to the switching instruction, the method further includes:

[0036] The steering ratio value after the switch is stored as the memory steering ratio;

[0037] Prior to obtaining the user instruction for the steering ratio, the method further includes:

[0038] Call the memory steering ratio.

[0039] Furthermore, after obtaining the user instruction for the steering ratio, the method further includes:

[0040] Determine whether the steering ratio of the user command and the memory steering ratio are the same;

[0041] If not, proceed to the next step.

[0042] Furthermore, after determining whether the steering ratio of the user instruction and the memory steering ratio are the same, the method further includes:

[0043] If so, send a notification alert.

[0044] A second aspect of this application provides a steering ratio switching device for use in a steer-by-wire system, comprising: a command receiving module, a status acquisition module, a control processing module, and a steering ratio switching module; wherein...

[0045] The instruction receiving module is used to receive user instructions for switching steering ratios and send the user instructions to the control processing module;

[0046] The status acquisition module is used to acquire the driving status of the vehicle and send the driving status to the control processing module;

[0047] The control processing module is used to generate a switching command based on the driving status and the user command;

[0048] The steering ratio switching module is used to execute the switching command to switch the steering ratio.

[0049] Furthermore, the driving state includes at least one of steering ratio, speed, steering angle, lateral acceleration, or steering wheel angle.

[0050] Furthermore, the switching instruction includes an immediate switching instruction and / or a delayed switching instruction; when the steering ratio switching module executes the immediate switching instruction, it quickly switches the steering ratio; when the steering ratio switching module executes the delayed switching instruction, it delays switching the steering ratio.

[0051] Furthermore, the steering ratio switching device also includes:

[0052] The data storage module is used to store the steering ratio after switching by the steering ratio switching module as a memory steering ratio;

[0053] The control processing module can call the memory steering ratio and generate a recovery command; the steering ratio switching module is used to execute the recovery command to restore the memory steering ratio.

[0054] Furthermore, the steering ratio switching device also includes a warning module; wherein,

[0055] The control processing module can compare the memory steering ratio with the user command; when the comparison result is successful, it sends a prompt command to the prompt alarm module; the prompt alarm module executes the prompt command to issue a prompt.

[0056] Furthermore, the control processing module is the main controller; the steering ratio switching module is the steering actuation assembly.

[0057] A third aspect of this application provides a vehicle including a steer-by-wire system and the steering ratio switching device described in the foregoing embodiments.

[0058] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0059] As can be seen from the above embodiments, the steering ratio switching method of this application can take into account various driving states of the vehicle and combine driving state and user instructions to form a targeted switching command, which helps to reduce the driving impact on the driver during the steering ratio switching process, making the driver's driving experience quieter and smoother. Therefore, it can improve the safety and stability of the steering ratio switching method.

[0060] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 A simplified schematic diagram of one embodiment of the steering ratio switching device of this application is shown.

[0063] Figure 2 A simplified schematic diagram of another embodiment of the steering ratio switching device of this application is shown.

[0064] Figure 3 The diagram shown is a flowchart of one embodiment of the steering ratio switching method of this application.

[0065] Figure 4 The diagram shows a flowchart of another embodiment of the steering ratio switching method of this application.

[0066] Figure 5 The diagram shown is a flowchart of yet another embodiment of the steering ratio switching method of this application.

[0067] The system includes a 100 steering ratio switching device, a 1 command receiving module, a 2 status acquisition module, a 3 control processing module, a 4 steering ratio switching module, a 5 data storage module, a 6 prompt alarm module, and a 200 steering ratio switching method. Detailed Implementation

[0068] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The manner described in the following exemplary embodiments does not represent all manner consistent with this application. Rather, they are merely examples of apparatuses consistent with some aspects of this application as detailed in the appended claims.

[0069] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are only used to distinguish different components. Similarly, the terms "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one, which will be separately stated if only "a" is referred to. "A plurality" or "several" means two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and / or "upper," etc., are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," etc., mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms “connection” or “link” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The singular forms “a,” “the,” and “the” used in this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0070] This application provides a vehicle including a steer-by-wire system. (Reference) Figure 1 The vehicle also includes a steering ratio switching device 100 for the steer-by-wire system. The steering ratio switching device 100 includes an instruction receiving module 1, a status acquisition module 2, a control processing module 3, and a steering ratio switching module 4. The instruction receiving module 1 receives user instructions to switch the steering ratio and sends these instructions to the control processing module 3. The status acquisition module 2 acquires the vehicle's driving status and sends this status to the control processing module 3; the control processing module 3 generates a switching instruction based on the driving status and the user instruction. The steering ratio switching module 4 executes the switching instruction to switch the steering ratio.

[0071] This configuration allows the driver to adjust the steering ratio based on road conditions and their own driving experience. At the same steering angle, a higher steering ratio requires more turns of the steering wheel, and vice versa. Therefore, at higher vehicle speeds, the driver can adjust to a higher steering ratio to improve stability, while at lower speeds, they can adjust to a lower steering ratio to reduce steering effort. The control processing module 3 also generates switching commands based on the driving status, minimizing the impact on driver input when changing steering ratios and improving driving safety.

[0072] The steering ratio switching device 100 is applied to a steer-by-wire system. Therefore, the control processing module 3 can be the main controller, and the steering ratio switching module 4 can be the steering actuation assembly. The main controller sends commands to the steering actuation assembly, which adjusts the steering ratio by adjusting the meshing position of the rack. Utilizing the decoupling characteristics of the steer-by-wire system, the adjustment of the steering ratio is more flexible and intelligent.

[0073] The steer-by-wire system includes a driver control assembly. This assembly is signal-connected to the steering actuator assembly via a main controller and includes a steering wheel. The steer-by-wire system can simulate the end of a rack based on rack travel parameters. When the steering ratio is large and the driver's steering angle is also large, to prevent the steering actuator motor from exceeding the actual gear's end position, the steering actuator assembly should also output a counterforce, thus prompting the user not to continue turning the steering wheel.

[0074] Steering ratio can be switched directly by changing the steering ratio value. Alternatively, the vehicle can have different preset driving modes, each with a different steering ratio. The driver can then switch driving modes to change the steering ratio. This method eliminates the need for users to have extensive technical knowledge of steering ratios; the driver simply selects the appropriate driving mode for different scenarios, making it convenient for them.

[0075] For example, a vehicle's driving modes include at least one of Comfort, Eco, Sport, Off-road, Sand, and Snow modes. In Comfort and Eco modes, to reduce passenger discomfort caused by weight shift, the steering ratio is adjusted to be larger, thus weakening the connection between steering and vehicle posture. In Sport mode, to improve vehicle handling under high-dynamic conditions, the number of steering wheel rotations needs to be reduced, therefore the steering ratio is adjusted to be smaller. In Off-road, Sand, and Snow modes, which are suitable for low-friction surfaces, to reduce the impact of steering causing the vehicle to get stuck, the system tends to weaken the connection between the driver's steering action and wheel angle, adjusting the steering ratio to be larger. In these modes, the steering ratio value can be the same, while suspension, drive, and braking parameters differ, thus providing the driver with different driving experiences even with the same steering ratio.

[0076] Switching driving modes affects multiple systems, including drive, steering, suspension, and braking. In some embodiments, the vehicle can also adjust the steering mode independently of the driving mode. For example, steering modes may include Standard, Comfort, and Sport modes. Different steering modes correspond to different steering ratios. When the driver switches to Comfort or Sport mode, the driving mode switches to Individual mode. In other words, at this point, only the steering ratio changes within the vehicle's system, while parameters such as suspension remain unchanged. This setting avoids confusion in adjustment logic and the accumulation of undesirable adjustments.

[0077] In some embodiments, the switching command includes at least one of an immediate switching command and a delayed switching command. When the steering ratio switching module 4 executes an immediate switching command, it quickly switches the steering ratio, thereby improving the switching efficiency. When the steering ratio switching module 4 executes a delayed switching command, it delays the switching of the steering ratio, thereby improving the stability of the steering ratio switching and avoiding adverse effects on the driver's driving operation caused by sudden changes in the steering ratio. For example, if the state acquisition module 2 detects that the vehicle is in a straight-line driving state and the vehicle state is stable, the control processing module 3 generates an immediate switching command to quickly switch the steering ratio. If the state acquisition module 2 detects that the vehicle is in a sharp turn and the vehicle state is unstable, the control processing module 3 generates a delayed switching command, and the steering ratio is switched only after the vehicle state stabilizes or after a preset time. In this way, the steering ratio switching device 100 can reduce the impact of the gear rack connected to the steering actuator motor, so as to avoid affecting the driver's operation when switching the steering ratio, thereby causing safety problems such as driving accidents.

[0078] refer to Figure 2To facilitate driver operation, in some embodiments, the steering ratio switching device 100 further includes a data storage module 5. The data storage module 5 stores the steering ratio switched by the steering ratio switching module 4 as a memory steering ratio. The control processing module 3 can recall the memory steering ratio and generate a restoration command. The steering ratio switching module 4 executes the restoration command to restore the memory steering ratio. When the driver finishes driving and leaves the vehicle, road conditions and driver preferences typically remain unchanged. Therefore, the steering ratio switching device 100 can remember the steering ratio from the last drive and automatically recall it when the vehicle is started again. This eliminates the need for the driver to specifically adjust the steering ratio every time they drive, improving the driver's driving experience and operational efficiency.

[0079] Furthermore, the steering ratio switching device 100 also includes a warning module 6. The control processing module 3 compares the memorized steering ratio with the user command. When the comparison is successful, a warning command is sent to the warning module 6. The warning module 6 executes the warning command to issue a warning. For example, if the vehicle starts and the steering ratio is adjusted to the memorized steering ratio of 16:1, and the driver subsequently adjusts the steering ratio to 16:1, the control processing module will find that the memorized steering ratio matches the user command. The vehicle can then emit a slight warning sound to alert the driver that a duplicate setting has been made. The warning module 6's setting reminds the user that the vehicle has received the adjustment command, but because it is repeated, the steering ratio adjustment function is not activated again, thus avoiding the user mistakenly believing that the vehicle system is sluggish and experiencing a poor user experience.

[0080] Based on the above embodiments, refer to Figure 3 This application also provides a steering ratio switching method 200 applied to a steer-by-wire system, comprising:

[0081] Step 210: Obtain the user command to switch the steering ratio.

[0082] User commands can be sent to the vehicle via a voice recognition system, or via control buttons on the center console or steering wheel. User commands can be direct commands such as "increase the steering ratio" or preset commands such as "switch the driving mode to snow mode," and this application does not limit this.

[0083] Step 220: Obtain the vehicle's driving status.

[0084] In various embodiments, the driving state includes at least one of steering ratio, speed, steering angle, lateral acceleration, or steering wheel angle. The vehicle's driving state can be used to determine whether the vehicle's current state allows for a change in steering ratio, or to determine how to perform such a change. For example, when the steering angle is small, the steering ratio can be changed instantly and quickly. The driving state may also include intelligent driving state and automatic parking state.

[0085] Step 230: Determine whether the driving status meets the switching conditions.

[0086] In this embodiment, if the driving state does not meet the switching conditions, the next step can be skipped, or the process can return to step 220. If the switching conditions are met, step 240 is then executed.

[0087] In some embodiments, the switching condition is that the steering angle is less than a preset angle value. A large steering angle can be considered as the vehicle making a sharp turn. If the steering ratio is switched at this time, the driver may experience problems such as loss of steering wheel control or inadequate steering angle adjustment due to the sudden change in steering ratio, affecting the driver's driving. Therefore, the steering ratio switching method 200 only adjusts the steering ratio when the driving state meets this switching condition, which can improve the safety of vehicle driving.

[0088] Furthermore, the preset angle value may include a first preset angle value and a second preset angle value, wherein the first preset angle value is less than the second preset angle value. Specifically, when the vehicle speed is greater than the preset speed value, the preset angle value is the first preset angle value. When the vehicle speed is less than or equal to the preset speed value, the preset angle value is the second preset angle value.

[0089] In other words, when the vehicle is traveling at high speed, the switching condition is that the steering angle is less than a smaller first preset angle value. When the vehicle is traveling at low speed, the switching condition is that the steering angle is less than a larger second preset angle value. When the vehicle is traveling at high speed, even a smaller steering angle can cause a larger angular deviation. Therefore, by setting the first and second preset angle values, appropriate switching commands can be generated for different vehicle speeds. The speed preset values ​​can be, for example, 80 km / h, 90 km / h, 100 km / h, etc., and this application is not limited to these.

[0090] Admittedly, the switching conditions could also be, for example, that the speed is less than a preset value or that the lateral acceleration is less than a preset value, and this application does not limit this.

[0091] Furthermore, if the driving state is intelligent driving mode or automatic parking mode, the steering ratio switching method 200 does not switch the steering ratio, meaning no switching command is generated. Since intelligent driving mode and automatic parking mode are autonomous vehicle control modes, if manual intervention is made to adjust the steering ratio at this time, it may disrupt vehicle control, causing problems such as vehicle control errors and driving hazards.

[0092] Step 240: If so, generate a switching instruction based on the user's instructions.

[0093] Generating a switching command based on user instructions means translating the user instructions into a language that the vehicle can recognize. For example, if the user instruction is to switch the steering ratio to 20:1, then the switching command is an electrical signal that the vehicle can recognize to switch the steering ratio to 20:1. By generating the switching command only after the switching conditions are met in the driving state, compared to a scheme that generates the switching command solely based on user instructions, the steering ratio switching method 200 takes into account the impact of driving state on steering ratio switching. Therefore, it can minimize the impact of changes in gear and rack meshing on the driver's driving experience and noise levels.

[0094] Step 250: According to the switching instruction, switch the steering ratio to a value that matches the user instruction.

[0095] With this setting, the steering ratio switching method 200 can take into account various driving states of the vehicle and combine driving states and user commands to form targeted switching commands, which helps to reduce the impact on the driver's driving during the steering ratio switching process, making the driver's driving experience quieter and smoother. Therefore, it can improve the safety and stability of the steering ratio switching method 200.

[0096] In some embodiments, the switching condition is that the vehicle's steering wheel angle changes and the steering wheel rotation passes zero. When the steering wheel is at zero, the tires of the wheels are pointing straight ahead, and the vehicle's direction of travel is also straight ahead. When the steering wheel rotation passes zero, the vehicle's direction of travel can be roughly determined to be a non-sharp turn. In this state, the change in the vehicle's steering ratio has a minimal impact on the driver, and the vehicle will not experience loss of control due to a sudden change in steering ratio.

[0097] Furthermore, the steering wheel angle can be changed within a range of 2° or greater and 8° or less. The steering ratio can only be switched after the steering wheel has been fully rotated through this range. This design allows the system to detect whether the driver is subjectively manipulating the steering wheel to switch the steering ratio. Moreover, steering wheel movements within this range do not cause excessive vehicle sway, thus enhancing driving safety. In some embodiments, the range is symmetrically positioned on either side of the zero point, allowing for steering ratio changes at the same angle whether the driver turns the steering wheel clockwise or counterclockwise. Alternatively, the range can be asymmetrically set according to the driver's personal preference; this application does not limit this.

[0098] In some extreme situations, the steering wheel may turn past zero and the range of change may also be within the range defined in this application. For example, when a vehicle is turning, the driver may quickly reverse the steering wheel to avoid suddenly appearing pedestrians, animals, or objects, causing the steering wheel to turn past zero. If the steering ratio switching is mistakenly triggered at this time, it may lead to the driver being unable to operate the vehicle as expected, resulting in loss of vehicle control. Therefore, in some embodiments, the speed of steering wheel angle change is less than a preset speed. When the steering wheel rotation speed is greater than the preset speed, the steering ratio switching is not initiated, thereby improving the safety performance of the steering ratio switching method 200.

[0099] In some embodiments, prior to step 210, the method further includes: identifying the power status of the vehicle.

[0100] The steer-by-wire system can only be activated when the vehicle's power mode is enabled. When the steer-by-wire system is in normal use, the main controller can send signals to the steering actuator, enabling the steering actuator to perform a series of operations such as steering and switching steering ratios.

[0101] based on Figure 3 The illustrated embodiment, with reference to Figure 4 In some embodiments, step 250 is followed by:

[0102] Step 260: Store the steering ratio value after the switch as the memory steering ratio.

[0103] Correspondingly, before step 210, the following steps are also included:

[0104] Step 201: Invoke the memory steering ratio.

[0105] In other words, the steering ratio control method 200 can remember the most recently used steering ratio in real time. After the vehicle is turned off and restarted, the steering ratio control method 200 directly recalls the previously used steering ratio. After the vehicle is turned off, the road conditions around the vehicle and the driver usually do not change. By recalling the memorized steering ratio, the driver does not need to adjust the steering ratio before each drive, thus the steering ratio control method 200 can improve the vehicle's intelligence and the driver's experience.

[0106] based on Figure 4 The illustrated embodiment, with reference to Figure 5 In some embodiments, after step 210, the method further includes:

[0107] Step 211: Determine whether the steering ratio of the user command and the memory steering ratio are the same.

[0108] If not, proceed to the next step, namely step 220.

[0109] With this setting, the steering ratio switching method 200 can determine whether the user command matches the vehicle's current steering ratio. If they do not match, it will proceed to the next step. This setting avoids increasing the computational load on the vehicle system due to user errors.

[0110] In some embodiments, after step 211, the method further includes:

[0111] Step 212: If so, send a notification alert.

[0112] In other words, in this embodiment, if the steering ratio specified by the user matches the vehicle's current steering ratio, the vehicle will issue a warning to inform the user that the vehicle will not switch steering ratios at this time. Step 212 avoids the situation where the vehicle fails to respond after multiple user commands due to a lack of steering ratio adjustment, leading the user to mistakenly perceive the steering ratio switching method 200 as sluggish or unresponsive. Therefore, the warning setting provides timely feedback to the user, improving the user experience.

[0113] based on Figure 3 or Figure 4 The illustrated embodiment, with reference to Figure 5 In some embodiments, step 240 may be set as follows:

[0114] Step 2401: If so, generate an immediate switching instruction based on the user's instructions.

[0115] Step 250 is set as follows:

[0116] Step 2501: Based on the real-time switching command, immediately switch the steering ratio to the value that matches the user command.

[0117] In this embodiment, the switching condition can be: the vehicle speed is greater than a preset speed value and the steering angle is less than a first preset angle value, or the vehicle speed is less than a preset speed value and the steering angle is less than a second preset angle value. That is, when the vehicle is traveling in a straight line or the steering angle is close to straight-line travel, the steering ratio switching method 200 immediately switches the steering ratio upon receiving a user command. To prevent excessive adjustment of the gears and rack during steering ratio adjustment, the gears and rack can be adjusted at a slower speed during steering ratio switching, thereby helping to ensure the accuracy of the adjustment.

[0118] Because the vehicle's steering angle is small when traveling in a straight line or near a straight line, the lateral acceleration is relatively small regardless of whether the vehicle speed is greater than or less than the preset speed value. If the switching conditions detect an abnormal lateral acceleration, that is, if the lateral acceleration is greater than the preset acceleration value, then step 230 can also determine that the switching conditions are not met. Therefore, the switching conditions can further include: lateral acceleration less than the preset acceleration value, thereby further improving the safety of the steering ratio switching method 200.

[0119] In other embodiments, step 240 may be configured as follows:

[0120] Step 2402: If not, generate a delayed switching instruction based on the user's instructions.

[0121] Wherein, control method 200 further includes, after step 2402:

[0122] Step 241: Obtain the vehicle's driving status;

[0123] Step 242: Determine whether the driving status meets the delay switching conditions.

[0124] Step 250 is set as follows:

[0125] Step 2502: If so, switch the steering ratio to a value that matches the user command according to the delay switching instruction.

[0126] In other words, after step 230 determines that the current driving state does not meet the switching conditions, the steering ratio switching method 200 acquires the vehicle's driving state in real time, and only switches the steering ratio when the vehicle's driving state meets the delayed switching conditions. With this setup, the vehicle can maintain its current steering ratio even when the steering ratio switching conditions are not met, while the steering ratio switching method 200 adjusts the vehicle's steering ratio at the appropriate time. Thus, the user does not need to manually determine whether a steering ratio switch is suitable. Furthermore, user commands issued at any time are captured and executed by the vehicle. In addition, timely steering ratio switching improves vehicle stability and driving safety.

[0127] Similar to the above embodiments, the switching condition can be: the vehicle speed is greater than a preset speed value and the steering angle is less than a first preset angle value, or the vehicle speed is less than a preset speed value and the steering angle is less than a second preset angle value. In other words, when the driving state does not meet the switching condition, the vehicle is making a large-angle turn. If the steering ratio is switched at this time, it will affect the driver's judgment of the turning angle, causing driving instability and danger.

[0128] At low speeds, increasing the turning angle does not cause a significant increase in lateral acceleration because the lateral acceleration is relatively small. At high speeds, however, increasing the turning angle causes a significant increase in lateral acceleration. If the switching conditions detect abnormal lateral acceleration—that is, lateral acceleration exceeding a preset acceleration value—then step 230 can also determine that the switching conditions are not met. Therefore, the switching conditions can further include: lateral acceleration less than a preset acceleration value, thereby further improving the safety of the steering ratio switching method 200.

[0129] In the above embodiments, the delayed switching condition can be: the steering angle is less than a preset angle value and the duration is greater than or equal to a preset time. A steering angle less than the preset angle value means that the vehicle has resumed straight-line driving. A duration greater than or equal to the preset time means that the vehicle is now traveling on a stable straight road, rather than in a situation of possible continuous turns. With this setting, the steering ratio switching method 200 can ensure driving safety during switching as much as possible and reduce the impact of the shock generated during rack and pinion switching on the driver.

[0130] In some embodiments, the method further includes the following after step 242:

[0131] If so, determine whether the direction of steering wheel rotation is the same as the target turning angle.

[0132] If so, the steering ratio is quickly switched to the value matching the user command according to the delayed switching instruction; otherwise, the steering ratio is slowly switched to the value matching the user command according to the delayed switching instruction.

[0133] When the steering wheel is turned in the same direction as the target angle, the steering ratio can be adjusted more quickly, thus rapidly reaching the target angle. When the steering wheel is turned in the opposite direction to the target angle, the steering ratio is adjusted more slowly to avoid inaccurate meshing of the gear and rack, thereby effectively ensuring the accuracy of the adjustment.

[0134] The steering ratio switching method 200 can adjust the steering ratio at different speeds, thus allowing for the selection of a suitable switching method 200 for different vehicle conditions. This helps to minimize the impact of the shock generated during the steering ratio switching process on the driver and improve the accuracy of the steering ratio switching method 200.

[0135] It should be understood that the steering ratio switching method 200 may be able to generate only a delayed switching command or only an immediate switching command, and this application does not limit this.

[0136] In the above embodiments, in order to enable users to receive timely feedback from the vehicle, some or even all of the steps of the steering ratio switching method 200 can be displayed on the vehicle's central control panel, for example, in the form of pop-ups or progress bars, so as to avoid users mistakenly believing that the steering ratio switching method 200 has failed to start.

[0137] The specific embodiments described herein are merely illustrative examples of the spirit of this application. Those skilled in the art to which this application pertains may make various modifications, additions, or similar methods to the described specific embodiments without departing from the spirit of this application or exceeding the scope defined by the appended claims.

[0138] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A steering ratio switching method, applied to a steer-by-wire system, characterized in that, include: Obtain the user command to switch steering ratio; Obtain the vehicle's driving status; Determine whether the driving state meets the switching conditions; If so, a switching instruction is generated based on the user instruction; based on the switching instruction, the steering ratio is switched to a value matching the user instruction; If not, generate a delay switching instruction based on the user instruction; obtain the driving status of the vehicle; determine whether the driving status meets the delay switching condition; the delay switching condition is: the steering angle is less than the preset angle value and the duration is greater than or equal to the preset time; If so, the steering ratio is switched to a value matching the user instruction according to the delay switching instruction.

2. The steering ratio switching method according to claim 1, characterized in that, The driving state includes at least one of the following: steering ratio, speed, steering angle, lateral acceleration, or steering wheel angle.

3. The steering ratio switching method according to claim 1, characterized in that, The switching condition is: the steering wheel angle of the vehicle changes and the steering wheel rotation passes through zero point.

4. The steering ratio switching method according to claim 3, characterized in that, The speed at which the steering wheel angle changes is less than the preset speed.

5. The steering ratio switching method according to claim 3, characterized in that, The range of change in the steering wheel angle is greater than or equal to 2° and less than or equal to 8°.

6. The steering ratio switching method according to claim 1, characterized in that, The process of generating a switching instruction based on the user instruction is as follows: An instant switching instruction is generated based on the user's instructions; Wherein, the step of switching the steering ratio to a value matching the user instruction according to the switching instruction means: switching the steering ratio to a value matching the user instruction immediately according to the instant switching instruction.

7. The steering ratio switching method according to claim 1 or 6, characterized in that, The switching condition is: the steering angle is less than the preset angle value.

8. The steering ratio switching method according to claim 7, characterized in that, The preset angle value includes a first preset angle value and a second preset angle value, and the first preset angle value is less than the second preset angle value; Wherein, when the vehicle speed is greater than the speed preset value, the angle preset value is the first angle preset value; when the vehicle speed is less than or equal to the speed preset value, the angle preset value is the second angle preset value.

9. The steering ratio switching method according to claim 8, characterized in that, The switching condition is at least one of the following: The steering angle is less than a first preset angle value, and the lateral acceleration is less than an acceleration preset value; The steering angle is less than the second angle preset value, and the lateral acceleration is less than the acceleration preset value.

10. The steering ratio switching method according to claim 1, characterized in that, After determining whether the driving state meets the delay switching condition, the method further includes: If so, determine whether the direction of steering wheel rotation is the same as the target turning angle; If so, the steering ratio is quickly switched to a value matching the user command according to the delay switching instruction; otherwise, the steering ratio is slowly switched to a value matching the user command according to the delay switching instruction.

11. The steering ratio switching method according to claim 1, characterized in that, After switching the steering ratio to a value matching the user instruction according to the switching command, the method further includes: The steering ratio value after the switch is stored as the memory steering ratio; Prior to obtaining the user instruction for the steering ratio, the method further includes: Call the memory steering ratio.

12. The steering ratio switching method according to claim 11, characterized in that, After receiving the user instruction to obtain the steering ratio, the method further includes: Determine whether the steering ratio of the user command and the memory steering ratio are the same; If not, proceed to the next step.

13. The steering ratio switching method according to claim 12, characterized in that, After determining whether the steering ratio of the user instruction and the memory steering ratio are the same, the method further includes: If so, send a notification alert.

14. A steering ratio switching device, applied to a steer-by-wire system, characterized in that, The steer-by-wire system is used to perform the steering ratio switching method as described in any one of claims 1-13; The steering ratio switching device includes: a command receiving module, a status acquisition module, a control processing module, and a steering ratio switching module; wherein, The instruction receiving module is used to receive user instructions for switching steering ratios and send the user instructions to the control processing module; The status acquisition module is used to acquire the driving status of the vehicle and send the driving status to the control processing module; The control processing module is used to generate a switching command based on the driving status and the user command; The steering ratio switching module is used to execute the switching command to switch the steering ratio.

15. The steering ratio switching device according to claim 14, characterized in that, The driving state includes at least one of the following: steering ratio, speed, steering angle, lateral acceleration, or steering wheel angle.

16. The steering ratio switching device according to claim 14, characterized in that, The switching instructions include immediate switching instructions and / or delayed switching instructions; when the steering ratio switching module executes the immediate switching instruction, it quickly switches the steering ratio; when the steering ratio switching module executes the delayed switching instruction, it delays switching the steering ratio.

17. The steering ratio switching device according to claim 14, characterized in that, The steering ratio switching device further includes: The data storage module is used to store the steering ratio after switching by the steering ratio switching module as a memory steering ratio; The control processing module can call the memory steering ratio and generate a recovery command; the steering ratio switching module is used to execute the recovery command to restore the memory steering ratio.

18. The steering ratio switching device according to claim 17, characterized in that, The steering ratio switching device also includes a warning module; wherein... The control processing module can compare the memory steering ratio with the user command; when the comparison result is successful, it sends a prompt command to the prompt alarm module; the prompt alarm module executes the prompt command to issue a prompt.

19. The steering ratio switching device according to claim 14, characterized in that, The control processing module is the main controller; the steering ratio switching module is the steering actuation assembly.

20. A vehicle, characterized in that, Includes a steer-by-wire system and a steering ratio switching device as described in any one of claims 14-19.

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