Steering method, vehicle, and storage medium

Abstract

The present application provides a steering method, a vehicle, and a storage medium, wherein the vehicle independently controls each wheel based on an electronic mechanical braking system. The method includes: obtaining the vehicle's current steering wheel angle, current front wheel angle, and brake pedal opening; when the vehicle is in a steering state, determining whether the vehicle meets a preset steering correction condition based on the current steering wheel angle, current front wheel angle, and brake pedal opening; if the vehicle meets the preset steering correction condition, calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and current front wheel angle, and driving the electronic mechanical braking system to apply the corresponding target braking force to each wheel. This method solves the problem that when a vehicle is turning and driving too fast and the driver actively brakes, the vehicle may understeer or oversteer, or even cause safety hazards, thereby improving the safety of vehicle steering and driving stability.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and more particularly, to a steering method, a vehicle, and a storage medium in the field of vehicle technology. Background Art

[0002] With the rapid development of sensor and network communication technologies, the level of automotive electronics and intelligence has greatly increased, and by-wire technology has gradually been applied to the automotive field. The electronic mechanical brake system (EMB) is a key component of the vehicle's by-wire chassis. Its main feature is the elimination of the mechanical connection between the brake pedal and the brake. The brake control unit is responsible for processing electronic signals and controlling the system's actuator to output braking force to achieve braking.

[0003] Automobile steering systems are divided into two categories: mechanical and power steering. A mechanical steering system consists of a steering mechanism, a steering gear, and a steering transmission mechanism. This system uses the driver's physical strength as the steering energy, and all force transmission components are mechanical. A power steering system uses both the driver's physical strength and engine power as the steering energy.

[0004] In related technologies, the vehicle is dynamically controlled by monitoring the yaw angular velocity and adjusting the wheel braking force within a limited range to improve the vehicle's turning performance.

[0005] However, during a vehicle's cornering process, its steering performance is affected by factors such as the steering system, braking system, and chassis layout. In related technologies, the vehicle's braking system is unable to achieve independent control of all four wheels, resulting in difficulty turning and poor maneuverability. This is especially true when the driver suddenly brakes at excessive speeds. Emergency braking can cause the vehicle to understeer or oversteer, potentially posing a safety hazard. This issue urgently needs to be addressed. Summary of the Invention

[0006] The present application provides a steering method, a vehicle and a storage medium, which can effectively prevent the vehicle from understeering or oversteering, or even causing safety hazards, when the vehicle speed is too fast and the driver actively applies the brakes during the steering process. The method realizes a method for independently controlling the braking force of the four wheels, so that the vehicle can steer according to the driver's operating expectations, greatly improving the safety of vehicle steering and driving stability.

[0007] In a first aspect, a steering method is provided, in which a vehicle independently controls each wheel based on an electronic mechanical braking system, the method comprising: obtaining a current steering wheel angle, a current front wheel angle, and a brake pedal opening of the vehicle; when the vehicle is in a steering state, judging whether the vehicle satisfies a preset steering correction condition based on the current steering wheel angle, the current front wheel angle, and the brake pedal opening; if the vehicle satisfies the preset steering correction condition, calculating a target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, and driving the electronic mechanical braking system to apply the corresponding target braking force to each wheel.

[0008] Through the above technical solution, the present application can determine whether the current vehicle is in a steering state. Based on the current steering wheel angle, the current front wheel angle, the brake pedal opening, and other data such as the vehicle body state, the present application can comprehensively determine whether the current vehicle can output the driver's desired control. If the current vehicle state parameters meet the correction conditions preset in the present application, the target braking force corresponding to each wheel is calculated. As a result, the present application can obtain the current vehicle's driving state and body parameters to determine the vehicle's steering state. Based on the steering state, the target braking force for each wheel is calculated separately to perform vehicle steering corrections, thus realizing a method for independent control of the four-wheel braking force, allowing the vehicle to steer according to the driver's desired control, greatly improving the vehicle's steering safety and driving stability.

[0009] In combination with the first aspect, in some possible implementations, after determining whether the vehicle meets the preset steering correction condition based on the current steering wheel angle, the current front wheel angle and the brake pedal opening, it also includes: if the current vehicle does not meet the preset steering correction condition, braking the vehicle according to the braking force corresponding to the brake pedal opening.

[0010] Through the above technical solution, this application presets the conditions for determining whether active steering intervention is required. If the current vehicle does not meet the preset steering correction conditions, there is no need to intervene in the vehicle's steering, and the vehicle can be braked according to the braking force corresponding to the current brake pedal opening. As a result, this application can not activate the vehicle's steering correction strategy when the current vehicle's steering action meets the standard, thereby avoiding increasing the computing power load of the braking system, improving the driver's experience, and enhancing the intelligence of the vehicle.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target braking force corresponding to each wheel of the vehicle is calculated based on the current steering wheel angle and the current front wheel angle, including: obtaining the current speed of the vehicle, and calculating the target yaw angle of the vehicle based on the current speed and the current steering wheel angle; based on the target yaw angle, the current brake pedal opening and the current front wheel angle, searching a preset braking force calibration table to obtain the target braking force corresponding to each wheel of the vehicle.

[0012] Through the above technical solution, the present application calculates the target yaw angle of the vehicle based on the current vehicle speed and the current steering wheel angle, and can accurately judge the direction control and stability of the current vehicle during driving. Furthermore, the present application combines vehicle driving status data such as brake pedal opening and front wheel angle, and obtains the target braking force corresponding to each wheel of the vehicle by pre-calibrating the braking force calibration table. Therefore, the present application can obtain the target braking force corresponding to each wheel, realize independent control of the four-wheel braking force, enable the vehicle to steer according to the driver's operating expectations, and greatly improve the accuracy of the vehicle steering control.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the determining whether the vehicle meets the preset steering correction conditions based on the current steering wheel angle, the current front wheel angle and the brake pedal opening includes: calculating the front wheel target angle based on the current steering wheel angle; when the brake pedal opening is greater than the preset opening value, determining whether the vehicle meets the preset steering correction conditions based on the difference between the front wheel target angle and the current front wheel angle.

[0014] Through the above-mentioned technical solution, the present application provides conditions for determining whether the current vehicle requires steering correction. This application calculates the target front wheel angle. Since the driver shifts the front wheels left or right by turning the steering wheel, the present application can use this data to determine the vehicle's steering performance and stability. Furthermore, by determining the degree of brake pedal opening, the present application can determine the degree of opening applied by the driver to the brake pedal, thereby determining whether the driver is performing a braking operation. As a result, the present application can accurately respond to the driver's braking operation and determine whether their steering action requires intervention, effectively improving the safety and stability of vehicle steering.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, judging whether the vehicle meets the preset steering correction condition based on the difference between the front wheel target angle and the current front wheel angle includes: calculating a first difference between the front wheel target angle and the current front wheel angle, and calculating a second difference between the current front wheel angle and the front wheel target angle; if the first difference is greater than a first threshold value, or the second difference is greater than a second threshold value, it is determined that the vehicle meets the preset steering correction condition.

[0016] Through the above technical solution, the present application makes a difference between the front wheel target angle and the current front wheel angle, and makes a difference between the current front wheel angle and the target angle, and compares the two differences obtained with the preset thresholds respectively. The present application can accurately judge the steering state of the current vehicle, and then judge whether the current vehicle needs steering correction, so as to achieve precise control of the vehicle steering and greatly improve the pass rate of vehicle steering.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after calculating the first difference between the front wheel target angle and the current front wheel angle, and calculating the second difference between the current front wheel angle and the front wheel target angle, it also includes: if the first difference is greater than the first threshold value, it is determined that the vehicle is in an understeering state; if the second difference is greater than the second threshold value, it is determined that the vehicle is in an oversteering state.

[0018] Through the above technical solution, when the difference between the front wheel target angle and the current front wheel angle is too large, the present application judges that when the current vehicle is turning, the current front wheel angle value is small, and the vehicle may slide to the outside of the curve, and thus, its steering state is judged to be understeering; when the difference between the current front wheel angle and the front wheel target angle is too large, the present application judges that when the current vehicle is turning, the current front wheel angle of the vehicle is large, and the vehicle cannot follow the desired trajectory, and thus, the steering state of the current vehicle is judged to be oversteering.

[0019] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, it also includes: obtaining the steering intention of the vehicle, and determining the outer wheel and the inner wheel of the vehicle based on the steering intention; based on the steering state, the outer wheel and the inner wheel of the vehicle, judging whether the target braking force corresponding to each wheel meets the preset braking conditions; if the target braking force corresponding to each wheel meets the preset braking conditions, allowing the electronic mechanical braking system to be driven to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel.

[0020] Through the above technical solution, after calculating the target braking force corresponding to each wheel, the present application can combine the vehicle's steering intention, the vehicle's steering state, and the inner / outer wheels to determine whether the target braking force meets the preset braking conditions, thereby controlling the target braking force of each wheel based on the vehicle's real-time state. As a result, the present application applies the corresponding target braking force to each wheel when the vehicle meets the preset braking conditions, effectively avoiding the problem of misadjustment.

[0021] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the determination of whether the target braking force corresponding to each wheel meets the preset braking condition based on the steering state, the outer wheel of the vehicle and the inner wheel of the vehicle includes: if the steering state is an understeering state, then when the target braking force of the outer wheel of the vehicle is greater than the target braking force of the inner wheel of the vehicle, it is determined that the target braking force corresponding to each wheel meets the preset braking condition; if the steering state is an oversteering state, then when the target braking force of the outer wheel of the vehicle is less than the target braking force of the inner wheel of the vehicle, it is determined that the target braking force corresponding to each wheel meets the preset braking condition.

[0022] Through the above technical solution, this application provides conditions for determining whether a vehicle requires steering control. Based on the steering state and the target braking force of the inner and outer wheels, it determines whether the target braking force of each wheel is sufficient to successfully complete the steering operation. As a result, this application can achieve precise control of each wheel, while satisfying the driver's driving intentions and improving the vehicle's steering stability.

[0023] In a second aspect, a steering device is provided, in which the vehicle independently controls each wheel based on an electronic mechanical braking system, and the device includes: an acquisition module for acquiring the current steering wheel angle, the current front wheel angle and the brake pedal opening of the vehicle; a judgment module for judging whether the vehicle meets the preset steering correction condition based on the current steering wheel angle, the current front wheel angle and the brake pedal opening when the vehicle is in a steering state; and a control module for calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle when the vehicle meets the preset steering correction condition, and driving the electronic mechanical braking system to apply the corresponding target braking force to each wheel.

[0024] In combination with the second aspect, in some possible implementations, after determining whether the vehicle meets the preset steering correction condition based on the current steering wheel angle, the current front wheel angle and the brake pedal opening, the judgment module is also used to: if the current vehicle does not meet the preset steering correction condition, brake the vehicle according to the braking force corresponding to the brake pedal opening.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the control module is specifically used to: obtain the current speed of the vehicle, and calculate the target yaw angle of the vehicle based on the current speed and the current steering wheel angle; based on the target yaw angle, the current brake pedal opening and the current front wheel angle, search the preset braking force calibration table to obtain the target braking force corresponding to each wheel of the vehicle.

[0026] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the judgment module is specifically used to: calculate the front wheel target angle based on the current steering wheel angle; when the brake pedal opening is greater than the preset opening value, judge whether the vehicle meets the preset steering correction condition based on the difference between the front wheel target angle and the current front wheel angle.

[0027] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the judgment module is also used to: calculate a first difference between the front wheel target angle and the current front wheel angle, and calculate a second difference between the current front wheel angle and the front wheel target angle; when the first difference is greater than a first threshold value, or the second difference is greater than a second threshold value, it is determined that the vehicle meets the preset steering correction condition.

[0028] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, after calculating the first difference between the front wheel target angle and the current front wheel angle, and calculating the second difference between the current front wheel angle and the front wheel target angle, the judgment module is also used to: when the first difference is greater than the first threshold value, determine that the vehicle is in an understeering state; when the second difference is greater than the second threshold value, determine that the vehicle is in an oversteering state.

[0029] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, after calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, the control module is also used to: obtain the steering intention of the vehicle, and determine the outer wheel and the inner wheel of the vehicle based on the steering intention; based on the steering state, the outer wheel and the inner wheel of the vehicle, determine whether the target braking force corresponding to each wheel meets the preset braking conditions; when the target braking force corresponding to each wheel meets the preset braking conditions, allow the electronic mechanical braking system to be driven to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel.

[0030] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the target braking force corresponding to each wheel is judged based on the steering state, the outer wheel of the vehicle and the inner wheel of the vehicle to meet the preset braking condition. The control module is specifically used to: when the steering state is an understeering state, determine that the target braking force corresponding to each wheel meets the preset braking condition when the target braking force of the outer wheel of the vehicle is greater than the target braking force of the inner wheel of the vehicle; when the steering state is an oversteering state, determine that the target braking force corresponding to each wheel meets the preset braking condition when the target braking force of the outer wheel of the vehicle is less than the target braking force of the inner wheel of the vehicle.

[0031] In a third aspect, a vehicle is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method of the first aspect or any possible implementation of the first aspect.

[0032] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a vehicle structure according to a specific embodiment of the present application;

[0034] Figure 2 is a flow chart of the steering method provided in an embodiment of the present application;

[0035] Figure 3 is a schematic diagram of signal acquisition according to a specific embodiment of the present application;

[0036] Figure 4is a schematic diagram of target yaw calculation according to a specific embodiment of the present application;

[0037] Figure 5 is a schematic diagram of the control logic of a specific embodiment of the present application;

[0038] Figure 6 is a flow chart of a steering method according to a specific embodiment of the present application;

[0039] Figure 7 is a block diagram of a steering device provided in an embodiment of the present application;

[0040] Figure 8 It is a block diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will clearly and thoroughly describe the technical solutions in this application in conjunction with the accompanying drawings. In the description of the embodiments of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more than two.

[0042] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0043] The development of vehicle braking systems has gone through the process from traditional hydraulic vacuum braking, vacuum-assisted hydraulic braking systems, electric booster hydraulic braking systems, to the current purely electrically controlled electronic mechanical braking system (EMB), also known as the wire-controlled braking system. The controller in the electronic mechanical braking system can process electronic signals and control the system actuator to output braking force to complete braking.

[0044] At present, the braking system and steering system of vehicles equipped with wire control brake systems are not integrated, and precise control of each wheel cannot be achieved. During the turning process, especially when the speed is too fast, if the driver actively brakes, the vehicle will understeer or oversteer. If no intervention is taken, it may even cause safety hazards.

[0045] Therefore, in order to solve the above problems, the present application proposes a steering method, in which the vehicle independently controls each wheel based on an electronic mechanical braking system, and corrects the steering of the vehicle through a wire control brake system, so that the vehicle steers according to the driver's operating expectations, greatly improving the safety of vehicle steering and driving stability.

[0046] Next, the vehicle structure involved in the steering method of the embodiment of the present application will be described. Figure 1 , Figure 1 This is a schematic diagram of a vehicle structure according to a specific embodiment of the present application.

[0047] Specifically, if Figure 1 As shown, the steering method of the embodiment of the present application is implemented based on the electronic mechanical braking system, which can achieve independent control of the four wheels. In the vehicle of the embodiment of the present application, each wheel is equipped with a brake, such as Figure 1 Brake 1, brake 2, brake 3 and brake 4 are used to control each wheel according to the target braking force. For example, brake 1 can control the right front wheel. The electronic mechanical braking system of the embodiment of the present application includes two controllers: a front controller and a rear controller. The front controller is used to control brake 1 and brake 2, and the rear controller is used to control brake 3 and brake 4. Each controller contains two chips, such as Figure 1 Chips 1 and 2 in the front controller and chips 3 and 4 in the rear controller each control a brake. For example, chip 1 controls brake 1 to brake the right front wheel. This allows the present application to output different target braking forces to each wheel by controlling the caliper motor of each wheel.

[0048] In addition, in the embodiment of the present application, the chip integrated control unit main chip MCU (Microcontroller Unit), power chip, pre-drive module, signal acquisition module, variable angle transmission ratio module, and data processing module contained in the front and rear controllers are used to obtain and process vehicle speed, acceleration, steering angle and other data, and judge the vehicle status based on these data to control the operation of the brakes.

[0049] The steering method of an embodiment of the present application will be described below with reference to the accompanying drawings. The vehicle of the embodiment of the present application independently controls each wheel based on an electronic mechanical braking system.

[0050] Figure 2 This is a schematic flow chart of a steering method provided in an embodiment of the present application.

[0051] For example, Figure 2 As shown, the steering method includes the following steps:

[0052] In step S201 , the current steering wheel angle, current front wheel angle, and brake pedal opening of the vehicle are acquired.

[0053] It is understood that the driver controls the steering of the vehicle by manipulating the steering wheel. Therefore, the present application can monitor the steering wheel angle in real time through sensors to obtain the vehicle's steering state. Since the vehicle's current front wheel angle can reflect the angle at which the driver controls the front wheels to deviate to the left or right by manipulating the steering wheel, the present application can determine the vehicle's steering state and direction of travel based on the current front wheel angle. The present application can determine the force applied by the driver on the brake pedal based on the obtained brake pedal opening, and transmit this signal to the MCU to adjust the operation of the braking system.

[0054] In addition, the embodiment of the present application can obtain the actual output front wheel angle signal through the front wheel angle sensor, obtain the brake pedal opening signal in real time through the brake pedal sensor, and transmit the vehicle's current steering wheel angle signal, current front wheel angle signal and brake pedal opening signal to the controller of the electronic mechanical braking system.

[0055] Therefore, the present application can obtain the vehicle's driving status data so that the braking system can accurately respond to the driver's needs and improve the vehicle's steering safety and braking performance.

[0056] In step S202, when the vehicle is in a steering state, it is determined whether the vehicle meets a preset steering correction condition based on the current steering wheel angle, the current front wheel angle and the brake pedal opening.

[0057] It can be understood that the present application obtains data on the current steering wheel angle, the current front wheel angle and the brake pedal opening in step S201. Then, the electronic mechanical brake system controller can judge the driving state of the vehicle through the current steering wheel angle and the current front wheel angle. When the current steering wheel angle is greater than a certain value, the front wheel angle rotates by a corresponding angle, and it is determined that the current vehicle is in a turning state.

[0058] Furthermore, the electronic mechanical brake system controller of the embodiment of the present application can determine the current state of the vehicle through the collected relevant signals, that is, whether the steering correction conditions preset in the present application are met.

[0059] Optionally, in some embodiments, after determining whether the vehicle meets the preset steering correction conditions based on the current steering wheel angle, the current front wheel angle and the brake pedal opening, it also includes: if the current vehicle does not meet the preset steering correction conditions, braking the vehicle according to the braking force corresponding to the brake pedal opening.

[0060] Specifically, this application predefines conditions for determining whether steering correction is necessary. If the vehicle does not meet the predetermined steering correction conditions, the vehicle is braked based on the braking force corresponding to the brake pedal opening obtained in step S201. If the vehicle meets the predetermined steering correction conditions, the electronic mechanical braking system is required to actively intervene to ensure the safety and stability of vehicle steering. The following examples will specifically describe the predetermined steering correction conditions in embodiments of this application.

[0061] Therefore, the present application determines whether the vehicle meets the preset steering correction conditions before braking each wheel, which can effectively avoid misadjustment of the electronic mechanical braking system and ensure the safety of vehicle steering.

[0062] Optionally, in some embodiments, whether the vehicle meets the preset steering correction conditions is determined based on the current steering wheel angle, the current front wheel angle and the brake pedal opening, including: calculating the front wheel target angle based on the current steering wheel angle; when the brake pedal opening is greater than the preset opening value, determining whether the vehicle meets the preset steering correction conditions based on the difference between the front wheel target angle and the current front wheel angle.

[0063] Those skilled in the art will appreciate that the driver controls the left and right offset angles of the front wheels by manipulating the steering wheel, thereby adjusting the vehicle's direction of travel. Therefore, the present application calculates the target front wheel angle based on the current steering wheel angle to determine the vehicle's handling performance and stability. Furthermore, the present application determines whether the driver has applied the brakes based on the brake pedal opening. Specifically, when the currently acquired brake pedal opening exceeds the preset opening value in the present embodiment, a brake signal is transmitted to the MCU.

[0064] Specifically, the present application uses a front wheel angle sensor to obtain the vehicle's current front wheel angle, i.e., the actual output front wheel angle. The electronic mechanical brake system controller receives the steering wheel angle signal and divides the steering wheel angle by the variable angle transmission ratio to obtain the target front wheel angle, i.e., the theoretical front wheel angle. Furthermore, embodiments of the present application subtract the target front wheel angle from the current front wheel angle data and, based on the difference between the two, determine whether the vehicle meets the preset steering correction conditions.

[0065] Therefore, this application takes into account that the target turning angle of the front wheels can reflect the handling performance and stability of the vehicle. When judging whether the current vehicle needs steering correction, the current vehicle is controlled according to the deviation between the theoretical turning angle value and the actual turning angle value to ensure that the vehicle turns and drives according to the driver's expectations.

[0066] Optionally, in some embodiments, whether the vehicle meets the preset steering correction condition is determined based on the difference between the front wheel target angle and the current front wheel angle, including: calculating a first difference between the front wheel target angle and the current front wheel angle, and calculating a second difference between the current front wheel angle and the front wheel target angle; if the first difference is greater than a first threshold value, or the second difference is greater than a second threshold value, it is determined that the vehicle meets the preset steering correction condition.

[0067] It is understood that during a turn, the vehicle's front end may fail to enter the intended curve or may slide to the outside of the curve, indicating an understeer state. In other cases, the vehicle may slide to the inside of the curve, indicating an oversteer state. Therefore, to accurately determine the vehicle's current steering state, in addition to calculating the difference between the target front wheel angle and the current front wheel angle, this application also calculates the difference between the current front wheel angle and the target front wheel angle to accurately determine different vehicle steering states.

[0068] Specifically, the embodiments of the present application foresee a first threshold value and a second threshold value for the aforementioned difference. The difference between the target front wheel angle and the current front wheel angle is compared with the first threshold value, and the difference between the current front wheel angle and the target front wheel angle is compared with the second threshold value. This determines whether the vehicle meets the preset steering correction conditions, i.e., whether active intervention by the electronic mechanical braking system is required. Furthermore, this application does not specifically limit the values ​​of the first and second threshold values, and those skilled in the art may set them based on actual circumstances.

[0069] Optionally, in some embodiments, after calculating the first difference between the front wheel target angle and the current front wheel angle, and calculating the second difference between the current front wheel angle and the front wheel target angle, it also includes: if the first difference is greater than a first threshold value, determining that the vehicle is in an understeering state; if the second difference is greater than a second threshold value, determining that the vehicle is in an oversteering state.

[0070] Specifically, when the difference between the front wheel target angle and the current front wheel angle is too large, the present application judges that when the current vehicle is turning, the current front wheel angle value, that is, the actual front wheel angle is small, and the vehicle may slide to the outside of the curve, and thus, its steering state is judged to be an understeering state; when the difference between the current front wheel angle and the front wheel target angle is too large, the present application judges that when the current vehicle is turning, the current front wheel angle of the vehicle is large, and the vehicle cannot follow the desired trajectory, and thus, the steering state of the current vehicle is judged to be an oversteering state.

[0071] Based on the above embodiments, the present application can collect the required sensor signals through the electronic mechanical braking system controller, and judge the current state of the vehicle, and judge whether the vehicle has abnormal steering according to the difference between the front wheel target angle and the current front wheel angle, and then correct the steering of the current vehicle through the electronic mechanical braking system.

[0072] In step S203, if the vehicle meets the preset steering correction conditions, the target braking force corresponding to each wheel of the vehicle is calculated based on the current steering wheel angle and the current front wheel angle, and the electronic mechanical braking system is driven to apply the corresponding target braking force to each wheel.

[0073] Specifically, after determining that the current vehicle meets the preset steering correction conditions, the present application uses the electronic mechanical braking system controller to process the acquired vehicle driving state parameters to calculate the target braking force for each wheel. Ultimately, the electronic mechanical braking system controls the four-wheel brakes to output the target braking force, thereby controlling the wheel speeds of the inner and outer wheels to achieve vehicle steering correction. The following examples will specifically describe the vehicle steering correction strategy of the present application.

[0074] It should be noted that, when the embodiment of the present application drives the electronic mechanical brake system to apply the corresponding target braking force to each wheel, the target braking force is applied to the corresponding wheel by controlling the caliper motor corresponding to each wheel respectively.

[0075] Optionally, in some embodiments, the target braking force corresponding to each wheel of the vehicle is calculated based on the current steering wheel angle and the current front wheel angle, including: obtaining the current speed of the vehicle, and calculating the target yaw angle of the vehicle based on the current speed and the current steering wheel angle; based on the target yaw angle, the current brake pedal opening and the current front wheel angle, searching a preset braking force calibration table to obtain the target braking force corresponding to each wheel of the vehicle.

[0076] It can be understood that the target yaw angle of the vehicle is an important parameter for the driver to control the vehicle's driving direction and path during driving. It is related to the driver's adjustment of the steering wheel and brake pedal. Therefore, this application calculates the target yaw angle of the vehicle based on the current vehicle speed and the current steering wheel angle.

[0077] Specifically, various sensors are installed in the vehicle of the embodiment of the present application, such as a brake pedal sensor, a steering wheel angle sensor, etc. The electronic mechanical brake system controller can collect signals obtained by each sensor, such as Figure 3 As shown, Figure 3This is a schematic diagram of signal acquisition for a specific embodiment of the present application. The electronic mechanical brake system controller will collect and process longitudinal acceleration signals, lateral acceleration signals, yaw rate signals, brake pedal signals, wheel speed signals, gear signals, and front wheel angle signals, and calculate the target yaw rate based on the steering wheel angle and vehicle speed.

[0078] It should be noted that Figure 4 This is a schematic diagram of target yaw calculation for a specific embodiment of the present application. The target yaw angle of the embodiment of the present application can be calculated based on a single track model, such as Figure 4 As shown, the embodiment of the present application calculates the desired yaw based on the steering wheel angle and the Ackermann equation. In combination with the vehicle speed, the yaw rate limit is increased according to the vehicle's current motion state. The target yaw angle is then corrected based on the driver's operating state. After filtering, the calculated value is then compensated to increase system robustness, ultimately outputting the driver's desired target yaw angle. Furthermore, the electromechanical brake system controller of the embodiment of the present application calculates the target braking force for each wheel based on the target yaw angle and the collected signal, and outputs a request signal.

[0079] Furthermore, the present application takes into account that the yaw angle can determine the braking force of the left and right wheels. Therefore, the target braking force corresponding to each wheel is pre-calibrated according to the target yaw angle, and the actual braking force is corrected in combination with the vehicle speed and the front wheel angle to obtain a more accurate target braking force.

[0080] During the actual execution process, after the electronic mechanical braking system controller recognizes the braking force corresponding to the brake pedal opening, the electronic mechanical braking system actively intervenes, automatically compensates for the braking force, calculates the target yaw angle, obtains the target braking force by looking up the table, and corrects the braking force through real-time feedback of the vehicle speed signal, ultimately achieving precise control of each wheel.

[0081] Furthermore, in some embodiments, after calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, it also includes: obtaining the steering intention of the vehicle, and determining the outer wheels and the inner wheels of the vehicle based on the steering intention; based on the steering state, the outer wheels and the inner wheels of the vehicle, judging whether the target braking force corresponding to each wheel meets the preset braking conditions; if the target braking force corresponding to each wheel meets the preset braking conditions, allowing the driving electronic mechanical braking system to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel.

[0082] Among them, the vehicle's steering intention refers to the driver's need to turn or change the driving direction while driving, which can be judged based on the driver's operations such as turning the steering wheel, stepping on the accelerator, braking, changing lanes, etc.

[0083] It can be understood that when the vehicle is turning, the tire on the same side as the steering wheel rotation direction is the inner wheel of the vehicle, and the tire on the opposite side of the steering wheel rotation direction is the outer wheel of the vehicle. Therefore, the present application can distinguish between the outer wheels and the inner wheels of the vehicle based on the vehicle's steering intention, that is, the direction in which the driver controls the steering wheel rotation.

[0084] Specifically, the present application obtains the steering wheel angle signal through the electronic mechanical braking system controller to obtain the vehicle's steering intention, and determines whether the vehicle needs intervention of the steering control strategy in combination with the steering status and the outer wheels and inner wheels of the vehicle. When the vehicle meets the preset braking conditions, the electronic mechanical braking system controls the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel, so that the current steering action meets the driver's wishes and driving mode requirements. In this way, the vehicle's misadjustment can be effectively avoided and precise control of the vehicle's steering can be achieved.

[0085] Optionally, in some embodiments, based on the steering state, the outer wheels of the vehicle and the inner wheels of the vehicle, it is determined whether the target braking force corresponding to each wheel meets the preset braking conditions, including: if the steering state is an understeering state, then when the target braking force of the outer wheels of the vehicle is greater than the target braking force of the inner wheels of the vehicle, it is determined that the target braking force corresponding to each wheel meets the preset braking conditions; if the steering state is an oversteering state, then when the target braking force of the outer wheels of the vehicle is less than the target braking force of the inner wheels of the vehicle, it is determined that the target braking force corresponding to each wheel meets the preset braking conditions.

[0086] In some cases, the vehicle's steering state is an understeer state. If the target braking force of the vehicle's outer wheels is greater than the target braking force of the vehicle's inner wheels, it is determined that the target braking force corresponding to each wheel meets the preset braking conditions. At this time, it is necessary to increase the braking force of the vehicle's inner wheels to ensure that the vehicle passes the turn smoothly; in other cases, the vehicle's steering state is an oversteer state. If the target braking force of the vehicle's outer wheels is less than the target braking force of the vehicle's inner wheels, it is determined that the target braking force corresponding to each wheel meets the preset braking conditions. At this time, it is necessary to increase the target braking force of the vehicle's outer wheels to prevent the vehicle from skidding due to excessive speed during the turning process.

[0087] Therefore, in this application, when the vehicle turns and the driver steps on the brake pedal due to excessive speed, the electronic mechanical braking system intervenes and collects corresponding signals, judges the vehicle's usage status through the collected sensor signals, obtains the driver's control expectations based on the driver's steering wheel angle input, and judges whether the vehicle meets the preset braking conditions based on the difference between the target front wheel angle and the current front wheel angle. If the preset braking conditions are not met, the braking force is output normally according to the driver's needs. If the preset braking conditions are met, the electronic mechanical braking system controls the wheel speeds on both sides through the braking force to complete the driver's desired steering.

[0088] Based on the above embodiments, the present application can control the vehicle according to the vehicle steering correction strategy, effectively preventing the vehicle from turning and understeering or oversteering after the driver actively brakes due to excessive speed. In order to enable those skilled in the art to further understand the implementation of the steering method of the present application, the following examples are listed to schematically illustrate the control logic of the method.

[0089] Specifically, Figure 5 This is a schematic diagram of the control logic of a specific embodiment of the present application.

[0090] It should be noted that, as described in the above embodiments, in order to implement the steering method of the present application, Figure 5 As shown, in the electronic mechanical braking system of the embodiment of the present application, the structure of the control main chip needs to include but is not limited to the following modules: a variable angle transmission ratio module, a signal acquisition module, a data processing module, a control unit main chip and a pre-drive module.

[0091] Among them, the input of the variable angle transmission ratio module is the steering wheel angle signal. In the embodiment of the present application, the target front wheel angle is obtained by dividing the steering wheel angle by the variable angle transmission ratio; the signal acquisition module is used to collect sensor signals, including longitudinal acceleration signals, lateral acceleration signals, yaw angular velocity signals, brake pedal signals, wheel speed signals, gear signals and current front wheel angle signals, and calculates the target yaw angle based on the steering wheel angle and vehicle speed.

[0092] Optionally, the data processing module is used to compare the target front wheel angle obtained by the signal collected by the signal acquisition module and the variable angle transmission ratio module, and the deviation between the target front wheel angle and the current front wheel angle with a threshold value (the threshold is a set value). If the deviation exceeds the threshold, the electronic mechanical braking system needs to actively intervene. The data processing module then calculates the target braking torque of the wheel based on the target yaw angle and the collected signal and outputs a request signal.

[0093] Optionally, the control unit main chip is used to receive request signals and related signals from the data processing module and send instructions; the pre-drive module is used to output target braking force signals to the wheel brakes, and the wheel brakes apply braking force to the wheels to control the speed of the inner and outer wheels.

[0094] Therefore, the present application can realize a vehicle control method for independently controlling the four-wheel braking force. During the vehicle steering process, the vehicle steering is corrected through the electronic mechanical braking system so that the vehicle steers according to the driver's operating expectations.

[0095] Furthermore, the following examples will illustrate the process of the steering method of the present application. Figure 6 This is a flow chart of a steering method according to a specific embodiment of the present application. Figure 6 As shown, the method includes the following steps:

[0096] Step S601: The driver presses the brake pedal to perform a vehicle steering operation, and the electromechanical braking system begins to intervene;

[0097] Step S602: The electronic mechanical brake system controller collects required sensor signals and determines the vehicle status;

[0098] Step S603: confirming that the vehicle's steering is abnormal and that the electronic mechanical braking system is required to perform steering correction;

[0099] Step S604: the electronic mechanical brake system controller processes the signal data to obtain the target braking force of the four wheels;

[0100] Step S605: Control the four-wheel brakes to output target braking forces to control the wheel speeds of the inner and outer wheels, and correct the vehicle steering.

[0101] Therefore, the present application judges the steering state of the vehicle, corrects the steering of the vehicle when the current vehicle has a steering abnormality, calculates the target braking force of each wheel, achieves precise control of the four wheels, and improves the safety of vehicle steering and driving stability.

[0102] In summary, the steering method of the present application obtains the vehicle's current steering wheel angle, current front wheel angle and brake pedal opening. When the vehicle is in a steering state, it determines whether the vehicle meets the preset steering correction conditions based on the current steering wheel angle, current front wheel angle and brake pedal opening. When the vehicle meets the preset steering correction conditions, the target braking force corresponding to each wheel of the vehicle is calculated based on the current steering wheel angle and the current front wheel angle, and the electronic mechanical braking system is driven to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel.

[0103] Therefore, the present application can effectively avoid the problem that the vehicle may understeer or oversteer, or even cause safety hazards, when the vehicle speed is too fast and the driver actively steps on the brakes during the steering process. It realizes the independent control method of the four-wheel braking force, so that the vehicle can steer according to the driver's operating expectations, greatly improving the safety of vehicle steering and driving stability.

[0104] Figure 7 It is a structural schematic diagram of a vehicle steering device provided in an embodiment of the present application.

[0105] For example, Figure 7 As shown, the steering device 10 of the vehicle may include: an acquisition module 100 , a judgment module 200 and a control module 300 .

[0106] Among them, the acquisition module 100 is used to obtain the vehicle's current steering wheel angle, current front wheel angle and brake pedal opening; the judgment module 200 is used to judge whether the vehicle meets the preset steering correction conditions based on the current steering wheel angle, current front wheel angle and brake pedal opening when the vehicle is in a steering state; the control module 300 is used to calculate the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle when the vehicle meets the preset steering correction conditions, and drive the electronic mechanical braking system to apply the corresponding target braking force to each wheel.

[0107] Optionally, in some embodiments, after determining whether the vehicle meets the preset steering correction conditions based on the current steering wheel angle, the current front wheel angle and the brake pedal opening, the judgment module 200 is also used to: when the current vehicle does not meet the preset steering correction conditions, brake the vehicle with corresponding braking force according to the brake pedal opening.

[0108] Optionally, in some embodiments, the control module 300 is specifically used to: obtain the current speed of the vehicle, and calculate the target yaw angle of the vehicle based on the current speed and the current steering wheel angle; based on the target yaw angle, the current brake pedal opening and the current front wheel angle, search a preset braking force calibration table to obtain the target braking force corresponding to each wheel of the vehicle.

[0109] Optionally, in some embodiments, the judgment module 200 is specifically used to: calculate the front wheel target angle based on the current steering wheel angle; when the brake pedal opening is greater than the preset opening value, judge whether the vehicle meets the preset steering correction condition based on the difference between the front wheel target angle and the current front wheel angle.

[0110] Optionally, in some embodiments, the judgment module 200 is further used to: calculate a first difference between the front wheel target angle and the current front wheel angle, and calculate a second difference between the current front wheel angle and the front wheel target angle; when the first difference is greater than a first threshold value, or the second difference is greater than a second threshold value, determine that the vehicle meets the preset steering correction condition.

[0111] Optionally, in some embodiments, after calculating a first difference between the front wheel target angle and the current front wheel angle, and calculating a second difference between the current front wheel angle and the front wheel target angle, the judgment module 200 is further used to: determine that the vehicle is in an understeering state when the first difference is greater than a first threshold value; and determine that the vehicle is in an oversteering state when the second difference is greater than a second threshold value.

[0112] Optionally, in some embodiments, after calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, the control module 300 is further used to: obtain the steering intention of the vehicle, and determine the outer wheels and the inner wheels of the vehicle based on the steering intention; based on the steering state, the outer wheels and the inner wheels of the vehicle, determine whether the target braking force corresponding to each wheel meets the preset braking conditions; when the target braking force corresponding to each wheel meets the preset braking conditions, allow the driving electronic mechanical braking system to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel.

[0113] Optionally, in some embodiments, based on the steering state, the outer wheels of the vehicle and the inner wheels of the vehicle, it is determined whether the target braking force corresponding to each wheel meets the preset braking conditions. The control module 300 is specifically used to: when the steering state is an understeering state, determine that the target braking force corresponding to each wheel meets the preset braking conditions when the target braking force of the outer wheels of the vehicle is greater than the target braking force of the inner wheels of the vehicle; when the steering state is an oversteering state, determine that the target braking force corresponding to each wheel meets the preset braking conditions when the target braking force of the outer wheels of the vehicle is less than the target braking force of the inner wheels of the vehicle.

[0114] It should be noted that the above explanation of the steering method embodiment is also applicable to the steering device of this embodiment and will not be repeated here.

[0115] In this embodiment, the device can be divided into functional modules based on the above-described method examples. For example, each functional module can be mapped to a specific functional module, or two or more functions can be integrated into a single processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and represents only a logical functional division. In actual implementation, other division methods may be used.

[0116] It should be understood that the steering device provided in this embodiment is used to execute the above-mentioned steering method, and therefore can achieve the same effect as the above-mentioned implementation method, which will not be repeated here.

[0117] The embodiment of the present application also provides a vehicle, Figure 8 is a schematic diagram of the structure of the vehicle provided in the embodiment of the present application, such as Figure 8 As shown, the vehicle may include: a memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0118] When the processor 802 executes the program, the steering method provided in the above embodiment is implemented.

[0119] Furthermore, the vehicle further comprises:

[0120] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0121] The memory 801 is used to store computer programs that can be run on the processor 802.

[0122] The memory 801 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0123] If the memory 801, the processor 802, and the communication interface 803 are implemented independently, the communication interface 803, the memory 801, and the processor 802 can be connected to each other via a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0124] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0125] The processor 802 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0126] This embodiment also provides a computer-readable storage medium, which stores computer program code. When the computer program code runs on a computer, the computer executes the above-mentioned related method steps to implement the steering method provided in the above-mentioned embodiment.

[0127] The computer-readable storage medium provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0128] The above content is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A steering method, characterized in that: The vehicle independently controls each wheel based on an electromechanical braking system, which includes the following steps: Obtaining the current steering wheel angle, current front wheel angle, and brake pedal opening of the vehicle; When the vehicle is in a steering state, determining whether the vehicle satisfies a preset steering correction condition based on the current steering wheel angle, the current front wheel angle, and the brake pedal opening; and If the vehicle satisfies the preset steering correction condition, calculating a target braking force corresponding to each wheel of the vehicle according to the current steering wheel angle and the current front wheel angle, and driving the electronic mechanical braking system to apply the corresponding target braking force to each wheel; After calculating the target braking force corresponding to each wheel of the vehicle based on the current steering wheel angle and the current front wheel angle, the method further includes: obtaining a steering intention of the vehicle and determining an outer wheel and an inner wheel of the vehicle based on the steering intention; judging whether the target braking force corresponding to each wheel meets a preset braking condition based on the steering state, the outer wheel of the vehicle, and the inner wheel of the vehicle; and if the target braking force corresponding to each wheel meets the preset braking condition, allowing the electronic mechanical braking system to control the caliper motor corresponding to each wheel to apply the corresponding target braking force to each wheel; The determining whether the target braking force corresponding to each wheel satisfies a preset braking condition based on the steering state, the outer wheel of the vehicle, and the inner wheel of the vehicle includes: if the steering state is an understeering state, determining that the target braking force corresponding to each wheel satisfies the preset braking condition when the target braking force of the outer wheel of the vehicle is greater than the target braking force of the inner wheel of the vehicle; if the steering state is an oversteering state, determining that the target braking force corresponding to each wheel satisfies the preset braking condition when the target braking force of the outer wheel of the vehicle is less than the target braking force of the inner wheel of the vehicle.

2. The method according to claim 1, characterized in that After determining whether the vehicle satisfies the preset steering correction condition according to the current steering wheel angle, the current front wheel angle, and the brake pedal opening, the method further includes: If the vehicle does not meet the preset steering correction condition, the vehicle is braked according to the braking force corresponding to the brake pedal opening.

3. The method according to claim 1, characterized in that The calculating the target braking force corresponding to each wheel of the vehicle according to the current steering wheel angle and the current front wheel angle includes: The current speed of the vehicle is obtained, and a target yaw angle of the vehicle is calculated based on the current speed and the current steering wheel angle; based on the target yaw angle, the brake pedal opening and the current front wheel angle, a preset braking force calibration table is searched to obtain a target braking force corresponding to each wheel of the vehicle.

4. The method according to any one of claims 1 to 3, characterized in that The determining whether the vehicle satisfies a preset steering correction condition based on the current steering wheel angle, the current front wheel angle, and the brake pedal opening includes: Calculating a front wheel target angle according to the current steering wheel angle; When the brake pedal opening is greater than a preset opening value, whether the vehicle satisfies a preset steering correction condition is determined according to a difference between the front wheel target turning angle and the current front wheel turning angle.

5. The method according to claim 4, characterized in that The determining whether the vehicle satisfies a preset steering correction condition based on the difference between the front wheel target turning angle and the current front wheel turning angle includes: calculating a first difference between the front wheel target turning angle and the current front wheel turning angle, and calculating a second difference between the current front wheel turning angle and the front wheel target turning angle; If the first difference is greater than a first threshold value, or the second difference is greater than a second threshold value, it is determined that the vehicle meets the preset steering correction condition.

6. The method according to claim 5, characterized in that After calculating a first difference between the front wheel target turning angle and the current front wheel turning angle, and calculating a second difference between the current front wheel turning angle and the front wheel target turning angle, the method further includes: If the first difference is greater than the first threshold, determining that the vehicle is in an understeering state; If the second difference is greater than the second threshold, it is determined that the vehicle is in an oversteering state.

7. A vehicle, characterized in that: The vehicle includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steering method according to any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed, the steering method according to any one of claims 1 to 6 is implemented.

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