Speed ​​control method and device based on control target and new energy vehicle

Abstract

The present application provides a speed control method, device and new energy vehicle based on a control target. The method includes: collecting driver input signals and vehicle state parameters, and determining the control target of the vehicle based on the driver input signals and vehicle state parameters; when it is judged that the control target is vehicle speed control, calculating the acceleration coefficient, and adjusting the wheel speed based on the acceleration coefficient and the corresponding wheel speed control strategy; when it is judged that the control target is turning radius control, calculating the turning radius coefficient, and adjusting the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy; when the vehicle switches between different control targets, determining the speed control strategy of the vehicle, and adjusting the speed gradient of the wheel based on the speed control strategy. The present application can flexibly adjust the speed control strategy, ensure smooth switching between different control strategies, and improve the controllability and stability of the vehicle under different driving conditions.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a speed control method and device based on a control target, and a new energy vehicle. Background Art

[0002] Distributed drive technology has been widely used in modern electric vehicles because of its advantage of being able to control the four-wheel motors individually. By adjusting the torque of the four-wheel motors, distributed drive technology can replace the traditional mechanical differential lock and realize the electronic differential control function. This control method allows the left and right wheels of the vehicle to have a speed difference, so that the vehicle can pass through potholes stably when driving in a straight line and complete the steering operation smoothly when turning.

[0003] During the steering process, electronic differential control is the basic control method, but as the vehicle state and the driver's intention change, different control objectives may need to be achieved. These control objectives include vehicle speed control and turning radius control. In the prior art, there are problems such as single control strategy, non-smooth switching between different control strategies, and lack of effective comprehensive control strategy when two control objectives exist at the same time. Summary of the invention

[0004] In view of this, the embodiments of the present application provide a speed control method, device and new energy vehicle based on a control target to solve the problems existing in the prior art of a single control strategy, uneven switching, inability to dynamically adjust the speed, and reduced controllability and stability of vehicle driving.

[0005] In a first aspect of an embodiment of the present application, a speed control method based on a control target is provided, comprising: collecting driver input signals and vehicle state parameters, and determining the control target of the vehicle based on the driver input signals and the vehicle state parameters; when it is determined that the control target is vehicle speed control, calculating the acceleration coefficient according to the driver input signals and the vehicle state parameters, and adjusting the wheel speed based on the acceleration coefficient and the corresponding wheel speed control strategy; when it is determined that the control target is turning radius control, calculating the turning radius coefficient according to the vehicle state parameters, and adjusting the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy; when the vehicle switches between different control targets, judging based on the vehicle's current acceleration coefficient, turning radius coefficient, vehicle speed, and one or more conditions in the process of switching between positive and negative speeds of the wheels, and determining the corresponding speed control strategy based on the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the wheel speed to the target speed.

[0006] According to a second aspect of an embodiment of the present application, a speed control device based on a control target is provided, comprising: a determination module configured to collect a driver input signal and a vehicle state parameter, and determine a control target of the vehicle based on the driver input signal and the vehicle state parameter; a first wheel speed adjustment module configured to calculate an acceleration coefficient according to the driver input signal and the vehicle state parameter when the control target is determined to be vehicle speed control, and adjust the wheel speed based on the acceleration coefficient and the corresponding wheel speed control strategy; a second wheel speed adjustment module configured to calculate a turning radius coefficient according to the vehicle state parameter when the control target is determined to be turning radius control, and adjust the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy; a speed adjustment module configured to make a judgment based on one or more conditions in the process of switching between positive and negative speeds of the vehicle, and determining a corresponding speed control strategy based on the judgment result when the vehicle switches between different control targets, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the speed of the wheel to the target speed.

[0007] The third aspect of the embodiment of the present application provides a new energy vehicle, including a controller, a power system and a transmission system; the controller is used to implement the steps of the above-mentioned speed control method based on the control target, so as to adjust the speed gradient of the wheel through torque control using the speed control strategy, and send the target speed of the wheel to the power system; the power system is used to control the speed of the drive motor through the transmission system according to the target speed.

[0008] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0009] By collecting the driver input signal and the vehicle state parameters, and based on the driver input signal and the vehicle state parameters, the control target of the vehicle is determined; when it is determined that the control target is vehicle speed control, the acceleration coefficient is calculated according to the driver input signal and the vehicle state parameters, and the wheel speed is adjusted based on the acceleration coefficient and the corresponding wheel speed control strategy; when it is determined that the control target is turning radius control, the turning radius coefficient is calculated according to the vehicle state parameters, and the wheel speed is adjusted based on the turning radius coefficient and the corresponding wheel speed control strategy; when the vehicle switches between different control targets, it is judged based on the current acceleration coefficient, turning radius coefficient, vehicle speed and one or more conditions in the process of switching between the positive and negative speeds of the wheel, and the corresponding speed control strategy is determined according to the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the speed of the wheel to the target speed. The present application can flexibly adjust the speed control strategy, ensure smooth switching between different control strategies, and improve the controllability and stability of the vehicle under different driving conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 is a flow chart of a wheel speed distribution method based on multi-objective control provided in an embodiment of the present application;

[0012] Figure 2 It is a schematic diagram of the overall architecture based on upper-layer control and lower-layer control provided in an embodiment of the present application;

[0013] Figure 3 is a structural schematic diagram of a speed control device based on a control target provided in an embodiment of the present application;

[0014] Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0015] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0016] It should be understood that the various steps described in the method implementation of the present application can be performed in different orders and / or performed in parallel. In addition, the method implementation may include additional steps and / or omit the steps shown. The scope of the present application is not limited in this respect.

[0017] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc. mentioned in this application are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0018] It should be noted that the modifications of "one" and "plurality" mentioned in the present application are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0019] The new energy vehicles in the embodiments of this application refer to vehicles that use new energy (non-traditional petroleum and diesel energy) and have advanced technology. These vehicles use new power systems that can effectively reduce vehicle emissions, reduce environmental impact, and improve energy efficiency. The new energy vehicles in the embodiments of this application include but are not limited to the following types of vehicles: electric vehicles, secondary battery or fuel cell electric vehicles, and can also be applied to hybrid vehicles, including extended-range vehicles, plug-in hybrid vehicles, oil-electric hybrid vehicles, etc.

[0020] A vehicle anti-skid control method and device provided according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0021] Figure 1 FIG. 1 is a flow chart of a wheel speed allocation method based on multi-objective control provided in an embodiment of the present application. Figure 1 As shown, the wheel speed allocation method based on multi-objective control may specifically include:

[0022] S101, collecting driver input signals and vehicle state parameters, and determining a vehicle control target based on the driver input signals and vehicle state parameters;

[0023] S102, when it is determined that the control target is vehicle speed control, the acceleration coefficient is calculated according to the driver input signal and the vehicle state parameter, and the wheel speed is adjusted based on the acceleration coefficient and the corresponding wheel speed control strategy;

[0024] S103, when it is determined that the control target is turning radius control, calculating the turning radius coefficient according to the vehicle state parameter, and adjusting the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy;

[0025] S104, when the vehicle switches between different control targets, a judgment is made based on the vehicle's current acceleration coefficient, turning radius coefficient, vehicle speed, and one or more conditions during the switching process of the positive and negative speeds of the wheels, and a corresponding speed control strategy is determined according to the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the wheel speed to the target speed.

[0026] In some embodiments, during the driving process of the vehicle, the VCU (Vehicle Control Unit) is used to monitor the driver input signals and vehicle status parameters in real time to obtain real-time data. The driver input signals and vehicle status parameters include but are not limited to the following parameters: pedal opening, pedal opening change rate, vehicle acceleration mode, vehicle available power, tire side slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration, etc. In practical applications, the vehicle controller (VCU) monitors the above vehicle status parameters in real time, and through high-frequency sampling, ensures that the acquired motor speed data is real-time and accurate. The built-in processing unit of the VCU processes the collected vehicle status parameters to obtain data for subsequent calculations.

[0027] For example, in some embodiments, the pedal opening, pedal opening change rate, vehicle acceleration mode and vehicle available power in the above-mentioned driver input signal and vehicle status parameters can be used to determine whether the vehicle's control target is vehicle speed control, and can further determine whether the vehicle speed control is acceleration control or deceleration control; for the specific judgment process and embodiments, please refer to the following content on judging whether the vehicle meets the preset vehicle speed control target conditions based on the pedal opening, pedal opening change rate, vehicle acceleration mode and vehicle available power.

[0028] In other embodiments, the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration in the above-mentioned driver input signal and vehicle state parameters can be used to determine whether the control target of the vehicle is turning radius control, and can further determine whether the turning radius control is to reduce the turning radius or increase the turning radius; for the specific judgment process and embodiments, please refer to the following content on judging whether the vehicle meets the preset turning radius control target conditions based on the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration.

[0029] First, before describing the technical solution of the present application in detail, the basic working principle of the electronic differential control is introduced in combination with the embodiments, which may specifically include the following contents:

[0030] Electronic differential control recognizes the driver's intention and vehicle state parameters, and controls the four-wheel speed to achieve relevant control goals. Currently, different control goals are identified according to different driver intentions and vehicle state parameters to complete wheel speed allocation. The basic wheel speed allocation strategy is:

[0031]

[0032]

[0033]

[0034]

[0035] in, Indicates the left front wheel speed, Indicates the right front wheel speed, Indicates the left rear wheel speed, Indicates the right rear wheel speed, Indicates vehicle speed. Indicates the difference in wheel speed between the inside and outside of the vehicle. The average vehicle speed V ave =V 1 +V 2 +V 3 +V 4 =V, turning radius , b represents the distance between the left and right wheels.

[0036] It should be noted that the embodiment of the present application takes the scenario of the vehicle turning left as an example to explain the process of the speed control method based on the control target provided by the present application. However, it should be understood that the speed control method based on the control target of the present application is not limited to the scenario of the vehicle turning left, and this scenario does not constitute a limitation on the technical solution of the present application.

[0037] In some embodiments, determining a control target of a vehicle based on a driver input signal and a vehicle state parameter includes:

[0038] Determine whether the vehicle meets the preset speed control target conditions through the pedal opening, pedal opening change rate, vehicle acceleration mode and vehicle available power;

[0039] Among them, the pedal opening, the pedal opening change rate and the available power of the whole vehicle are compared with the corresponding thresholds respectively, and according to the comparison result and the vehicle acceleration mode, it is judged that the control target of the vehicle is acceleration control or deceleration control.

[0040] Specifically, when the driver steps on the accelerator pedal (this is not a timing limitation, but a condition limitation), the system monitors the size of the pedal opening and the rate of change of the pedal opening in real time. The pedal opening indicates the degree of acceleration the driver wants to achieve, while the rate of change of the pedal opening reflects the urgency of the driver's acceleration. At the same time, the system will also detect the current vehicle acceleration mode, which can be selected by the driver on the control panel in the car, usually including economy mode, comfort mode and sports mode. In addition, the system will obtain the available power of the entire vehicle, which is determined by the battery's state of charge (SOC) and the maximum allowable output drive power of the motor.

[0041] Furthermore, when the system detects that the pedal opening, pedal opening rate, vehicle acceleration mode and vehicle available power have all reached the preset thresholds, the system will determine that the vehicle's control target is acceleration control. For example, when the pedal opening is greater than 40%, the pedal opening rate is greater than 90° / s, the vehicle acceleration mode is in sports mode and the vehicle available power is greater than 80kW, the system sets the vehicle's control target to acceleration control. In this case, the vehicle will adjust the wheel speed of each wheel according to the acceleration control target to achieve a faster acceleration response.

[0042] In addition, when the system detects that the pedal opening, pedal opening change rate, vehicle acceleration mode and vehicle available power are all lower than the preset threshold, the system will determine that the vehicle's control target is deceleration control. For example, when the pedal opening is less than 20%, the pedal opening change rate is less than 30° / s, the vehicle acceleration mode is in economic mode and the vehicle available power is less than 50kW, the system sets the vehicle's control target to deceleration control. In this case, the vehicle will adjust the wheel speed of each wheel according to the deceleration control target to achieve smooth deceleration and energy recovery.

[0043] For example, in a specific example, when the accelerator pedal opening, the accelerator pedal opening change rate, the vehicle acceleration mode, and the vehicle available power reach a threshold, it is determined that the control target is to increase the target vehicle speed:

[0044] (1) Accelerator pedal opening: , where U 100 The collected voltage corresponding to 100% of the accelerator pedal opening; U 0 is the collected voltage corresponding to the accelerator pedal being pressed down to 0% opening, and U is the collected voltage when the driver presses the pedal during driving.

[0045] (2) Accelerator pedal opening rate: , Represents the derivative of pedal opening with respect to time.

[0046] (3) Vehicle acceleration mode: The vehicle acceleration mode is selected by the driver on the large screen. There are three modes: economy, comfort and sport.

[0047] (4) Available power of the whole vehicle: The available power of the whole vehicle is obtained based on the battery SOC and the maximum drive power allowed by the motor.

[0048] The pedal opening P, the pedal opening change rate and the available power of the vehicle are compared with the corresponding thresholds respectively, and the speed control target of the vehicle is determined according to the threshold comparison results. For example, when it is determined that the pedal opening P>40%, the pedal opening change rate >90° / s, vehicle available power>80kW, and acceleration mode is sports mode, the control target is acceleration control mode; on the contrary, when it is judged that the pedal opening P<20%, the pedal opening change rate <30° / s, vehicle available power <50kW, and acceleration mode is economic mode, the control target is deceleration control mode.

[0049] Through the above method of this embodiment, the vehicle can dynamically adjust the control strategy according to the driver's intention and vehicle status to ensure optimal performance and stability under various driving conditions. This method not only improves the vehicle's handling performance, but also enhances driving comfort and safety.

[0050] In some embodiments, determining a control target of a vehicle based on a driver input signal and a vehicle state parameter includes:

[0051] Based on the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration, it is judged whether the vehicle meets the preset turning radius control target conditions; when the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration are all greater than the corresponding thresholds, it is judged that the control target of the vehicle is to reduce the turning radius.

[0052] Specifically, the system collects parameters related to the vehicle's steering and driving status through the vehicle's sensors, including tire slip angle, steering wheel angle, steering wheel angle change rate, and lateral acceleration. The following is an explanation of how to obtain the above parameters and their contents, which may specifically include the following:

[0053] Tire slip angle: measured by sensors installed on the wheels. The tire slip angle reflects the deflection angle between the wheel and the vehicle body, and can reveal the state of the vehicle when turning. Specifically, the tire slip angles of the front and rear axles are calculated through the data detected by the wheel sensors.

[0054] Steering wheel angle: Measured directly by the steering wheel sensor, it reflects the driver's steering intention.

[0055] Steering wheel angle change rate: By detecting the rotation speed of the steering wheel, the steering wheel angle change rate is calculated. This parameter can reflect the speed at which the driver turns the steering wheel.

[0056] Lateral acceleration: Measured by the lateral acceleration sensor, lateral acceleration reflects the lateral force applied to the vehicle when it turns.

[0057] In the specific implementation process, the system will monitor the above parameters. When these parameters reach the preset threshold, the system will determine that the vehicle needs to enter a control mode that reduces the turning radius. For example:

[0058] When the difference in tire slip angles between the front and rear axles is greater than 1 degree, or the difference in tire slip angles between the inner and outer sides of the same axle is greater than 4 degrees, it means that the vehicle's posture is unstable when turning and needs to be adjusted.

[0059] When the steering wheel angle is greater than 10 degrees and the steering wheel angle change rate is greater than 5 degrees per second, it indicates that the driver is performing a more drastic steering operation.

[0060] When the lateral acceleration is greater than 0.4g, it means that the vehicle is subjected to a large lateral force when turning, which may cause the turning radius to be too large and require correction.

[0061] When the above conditions are met, the system determines that the vehicle's control target is to reduce the turning radius. Then, the system will adjust the wheel speed distribution of each wheel according to these parameters to achieve the goal of reducing the turning radius. The specific steps are as follows:

[0062] Data collection: Through the sensor system, data such as tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration are collected in real time.

[0063] Judgment condition: Compare the collected data with the preset threshold to determine whether the conditions for reducing the turning radius are met. If all parameters reach the corresponding threshold, the control mode of reducing the turning radius is entered.

[0064] Adjust wheel speed distribution: Dynamically adjust the wheel speed distribution of each wheel according to the current vehicle status and turning requirements. The specific strategy is to prioritize the speed difference between the left and right wheels on the front axle to reduce the turning radius. The system will optimize the wheel speed distribution according to the real-time status of the vehicle to ensure that the vehicle maintains stable and efficient steering performance during the turning process.

[0065] For example, in a specific example, when the tire slip angle α, the steering wheel angle δ, the steering wheel angle change rate, and the lateral acceleration a y After reaching the threshold, the control target is determined to be to reduce the turning radius.

[0066] (1) Tire slip angle: ; , where V x , V y are the longitudinal and lateral speeds of the vehicle, γ is the yaw rate, the above three parameters are all obtained through sensors, a and b are the distances from the center of mass to the front and rear axles;

[0067] (2) Steering wheel angle δ: obtained through the steering angle sensor;

[0068] (3) Steering wheel angle change rate: , represents the derivative of the steering wheel angle with respect to time;

[0069] (4) Lateral acceleration: obtained from the lateral acceleration sensor.

[0070] When judging α 前轴 -α 后轴 >1° or coaxial α 内侧 -α 外侧 >4°, δ>10°, >5° / s,a y When the speed is >0.4g, it is determined that the vehicle has entered the control target stage of reducing the turning radius.

[0071] Through the method of the present embodiment described above, the vehicle can intelligently adjust the turning radius under complex driving conditions, improve the vehicle's handling and stability, and provide the driver with a safer and more comfortable driving experience.

[0072] In some embodiments, when it is determined that the control target is vehicle speed control, the acceleration coefficient is calculated according to the driver input signal and the vehicle state parameter, including:

[0073] When the control target of the vehicle is acceleration control or deceleration control, the acceleration coefficient is determined according to the pre-established acceleration coefficient mapping relationship using the vehicle's current pedal opening, pedal opening change rate and vehicle available power;

[0074] Among them, the value of the acceleration coefficient is positively correlated with the pedal opening, the pedal opening change rate and the value of the available power of the vehicle.

[0075] Specifically, when the vehicle's control target is determined to be vehicle speed control, the system uses these parameters to query the pre-established acceleration coefficient mapping relationship. The mapping relationship is a database related to the vehicle's acceleration performance, which records the acceleration coefficient under different pedal openings, pedal opening change rates, and vehicle available power conditions. Specifically, the value of the acceleration coefficient is positively correlated with the pedal opening, pedal opening change rate, and vehicle available power, that is, the larger the pedal opening, the faster the pedal opening change rate, and the higher the vehicle available power, the greater the acceleration coefficient.

[0076] Furthermore, in order to establish the mapping relationship of the acceleration coefficient, during the vehicle design phase, the acceleration coefficient values ​​under different working conditions are determined through a large amount of experimental data and simulation results. For example, the system can record the vehicle acceleration performance under different pedal openings (such as 20%, 50%, 80%, etc.), different pedal opening change rates (such as 20° / s, 50° / s, 100° / s, etc.) and different vehicle available power (such as 30kW, 60kW, 90kW, etc.), and then form these data into a two-dimensional or three-dimensional map.

[0077] In actual operation, when the system determines that the vehicle needs to be accelerated or decelerated, the system will query the map to obtain the corresponding acceleration coefficient based on the current pedal opening, pedal opening change rate and vehicle available power. For example, when the driver's pedal opening is 50%, the pedal opening change rate is 60° / s, and the vehicle available power is 70kW, the system will find the corresponding acceleration coefficient K in the map. v .

[0078] Once the acceleration factor K is determined v , the system will use this coefficient to calculate the target average speed. For example, if the current average speed is V, the acceleration coefficient K v After adjustment, the target average speed is K v Multiply by V. This approach ensures that the vehicle can adjust the acceleration performance in real time according to the driver's intention and vehicle status under various conditions to provide a better driving experience.

[0079] For example, in a specific example, when the vehicle enters the vehicle speed control mode, the pedal opening angle P and the pedal opening angle change rate are firstly , The available power of the vehicle is established and the acceleration coefficient K v The map diagram shows that the larger the pedal opening, the greater the pedal opening change rate, the greater the available power of the vehicle, and the greater the acceleration coefficient, K v The value range is (1-ΔV / 4V) ~ (1+ΔV / 4V).

[0080] By calculating and adjusting the acceleration coefficient, the vehicle can flexibly respond to different driving requirements, which not only improves the acceleration performance, but also enhances the driving smoothness and responsiveness. This embodiment shows how to use the driver input signal and vehicle state parameters to dynamically adjust the acceleration coefficient, thereby achieving precise vehicle speed control.

[0081] In some embodiments, adjusting the wheel speed based on the acceleration coefficient and the corresponding wheel speed control strategy includes:

[0082] The target average vehicle speed is calculated according to the acceleration coefficient, and the wheel speed corresponding to each wheel is determined according to the target average vehicle speed and the current vehicle speed and the average vehicle speed, and the wheel speed is allocated to the corresponding wheel.

[0083] Specifically, the acceleration factor (K) is obtained through the above steps. v ), and use the acceleration factor to calculate the target average speed. The target average speed is based on the current vehicle average speed (V ave ) multiplied by the acceleration factor (K v ) obtained.

[0084] Furthermore, when the target average speed is determined, the system will determine the wheel speed distribution of each wheel based on the target average speed and the current speed of the vehicle. This process is designed to ensure that when the vehicle is accelerating or decelerating, the speed adjustment of each wheel can meet the overall acceleration requirements of the vehicle and maintain a stable driving state.

[0085] Furthermore, in the vehicle speed control mode, the system will first keep the wheel speed of the left wheel unchanged. For example, if the current wheel speed of the left front wheel and the left rear wheel is V, then after the adjustment, the wheel speed of the left front wheel and the left rear wheel will still be V. For the right wheel, the system will make corresponding wheel speed adjustments based on the difference between the target average speed and the current average speed. The specific wheel speed distribution method is as follows:

[0086] Keep the left wheel speed unchanged: the wheel speed of the left front wheel and the left rear wheel remains at the current vehicle speed V.

[0087] Adjust the wheel speed of the right wheel: The wheel speed of the right front and rear wheels will be increased compared to the wheel speed of the left wheel by a specific value, which is four times the difference between the target average speed and the current average speed.

[0088] For example, assuming the target average vehicle speed (V ave ’ ) is greater than the current average vehicle speed (V ave ) is higher than a certain value. In this case, the wheel speed distribution of the right front wheel and the right rear wheel is as follows:

[0089] The left front wheel speed is maintained at V.

[0090] The right front wheel speed is adjusted to V plus 4 times the difference between the target average vehicle speed and the current average vehicle speed.

[0091] The left rear wheel speed is maintained at V.

[0092] The right rear wheel speed is adjusted to V plus 4 times the difference between the target average vehicle speed and the current average vehicle speed.

[0093] For example, in a specific example, the average vehicle speed V in the vehicle speed control mode is ave ’ =K v *V. The principle of wheel speed distribution is: keep the left wheel speed at V, and the sum of the wheel speeds of the front and rear wheels on the right side should be increased by 4 (V ave ’ -V ave ).Right now:

[0094]

[0095]

[0096]

[0097]

[0098] in, Indicates the left front wheel speed, Indicates the right front wheel speed, Indicates the left rear wheel speed, Indicates the right rear wheel speed, Indicates vehicle speed. represents the target average vehicle speed, Indicates the current average vehicle speed.

[0099] In another scenario, if the vehicle requires a smoother acceleration distribution, for example, the wheel speed of the right front wheel increases by twice the difference between the target average speed and the current average speed than the left front wheel, and the wheel speed of the right rear wheel also increases by twice the difference, then the wheel speed distribution is as follows:

[0100] The left front wheel speed is maintained at V.

[0101] The right front wheel speed is adjusted to V plus 2 times the difference between the target average vehicle speed and the current average vehicle speed.

[0102] The left rear wheel speed is maintained at V.

[0103] The right rear wheel speed is adjusted to V plus 2 times the difference between the target average vehicle speed and the current average vehicle speed.

[0104] For example, in a specific example, the average vehicle speed V in the vehicle speed control mode is ave ’ =K v *V. The principle of wheel speed distribution is: keep the left wheel speed at V, and the sum of the right front and rear wheel speeds should be increased by 2 (V) compared to the left wheel speed. ave ’ -V ave ).Right now:

[0105]

[0106]

[0107]

[0108]

[0109] in, Indicates the left front wheel speed, Indicates the right front wheel speed, Indicates the left rear wheel speed, Indicates the right rear wheel speed, Indicates vehicle speed. represents the target average vehicle speed, Indicates the current average vehicle speed.

[0110] Through the method of the present embodiment, the wheel speed distribution of the vehicle can be flexibly adjusted to ensure that under different acceleration requirements, the wheel speed adjustment of each wheel can meet the dynamic performance requirements of the entire vehicle. This not only improves the acceleration performance of the vehicle, but also enhances the driving smoothness and responsiveness, providing a better driving experience.

[0111] In some embodiments, when it is determined that the control target is turning radius control, the turning radius coefficient is calculated according to the vehicle state parameter, including:

[0112] When the control target of the vehicle is to reduce the turning radius, the turning radius coefficient is determined according to the pre-established turning radius coefficient mapping relationship using the current tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration of the vehicle;

[0113] Among them, the value of the turning radius coefficient is negatively correlated with the values ​​of the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration.

[0114] Specifically, when the system detects the turning demand of the vehicle, it will calculate the turning radius coefficient (K) based on the above parameters (tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration). R ). This coefficient is used to adjust the turning radius of the vehicle to ensure that the vehicle can remain stable and safe during the turning process.

[0115] Furthermore, in order to calculate the turning radius coefficient (K R ), the system uses the vehicle's current tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration to query the pre-established turning radius coefficient mapping relationship. The turning radius coefficient value is negatively correlated with these parameters, that is, the larger the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration, the larger the turning radius coefficient K. R The smaller.

[0116] In the specific implementation process, when entering the turning radius control target stage, the system will determine the appropriate turning radius coefficient K through a series of calculations and mappings. R Here are the detailed steps:

[0117] Data collection: The sensor system collects data such as the vehicle's tire slip angle, steering wheel angle, steering wheel angle change rate, and lateral acceleration in real time.

[0118] Judgment condition: Compare the collected data with the preset threshold to determine whether the turning radius needs to be reduced. If all parameters reach the corresponding threshold, the control mode of reducing the turning radius is entered.

[0119] Query mapping relationship: Use the currently collected tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration data to calculate the pre-established turning radius coefficient K R The corresponding turning radius coefficient is obtained by querying the mapping relationship. This mapping relationship is established through a large amount of experimental data and simulation results, and the turning radius coefficient values ​​under different working conditions are recorded.

[0120] Calculate wheel speed difference: According to the turning radius coefficient K obtained by query R , the system calculates the new left and right wheel speed difference. Since the turning radius is inversely proportional to the left and right wheel speed difference, by increasing the left and right wheel speed difference ΔV, the turning radius can be effectively reduced.

[0121] Adjust wheel speed distribution: Dynamically adjust the wheel speed distribution of each wheel based on the calculated wheel speed difference. The specific strategy is to prioritize the wheel speed difference between the left and right wheels on the front axle, thereby reducing the turning radius. The system will optimize the wheel speed distribution based on the real-time status of the vehicle to ensure that the vehicle maintains stable and efficient steering performance during the turn.

[0122] For example, in a specific example, when entering the turning radius control target stage, the radius formula is used It can be seen that only by increasing the left and right wheel speed difference ΔV can the turning radius R be reduced. Therefore, according to the tire slip angle α, steering wheel angle δ, steering wheel angle change rate, lateral acceleration a y Establish the turning radius factor K R The map diagram shows the tire slip angle α, steering wheel angle δ, steering wheel angle change rate, and lateral acceleration a. y The larger the K R The smaller the K R The value range is 0~1.

[0123] Through the method of the present embodiment described above, the vehicle can intelligently adjust the turning radius under complex driving conditions, improve the vehicle's maneuverability and stability, and provide the driver with a safer and more comfortable driving experience. This method not only improves the vehicle's turning performance, but also enhances the smoothness and responsiveness of driving, providing a better driving experience.

[0124] In some embodiments, adjusting the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy includes:

[0125] The initial turning radius is adjusted using the turning radius coefficient to obtain the adjusted turning radius. The left and right wheel speed difference is calculated based on the turning radius coefficient. The wheel speed corresponding to each wheel is determined based on the left and right wheel speed difference and the current vehicle speed, and the wheel speed is allocated to the corresponding wheel.

[0126] Specifically, the system first uses the turning radius coefficient (K R ) to adjust the initial turning radius (R) to obtain an adjusted turning radius. Specifically, the adjusted turning radius is the initial turning radius (R) multiplied by the turning radius coefficient (K R ).

[0127] Furthermore, based on the adjusted turning radius, the system calculates the new left and right wheel speed difference ( ). Specifically, the left and right wheel speed difference ( ) is equal to the initial left and right wheel speed difference ( ) divided by the turning radius factor (K R ). By increasing the speed difference between the left and right wheels, the turning radius can be effectively reduced, thereby meeting the turning needs of the vehicle.

[0128] Furthermore, after calculating the new left and right wheel speed difference, the system determines the wheel speed distribution of each wheel according to the current vehicle speed and the left and right wheel speed difference. The specific steps are as follows:

[0129] The left front wheel speed is adjusted to the current vehicle speed minus half of the left and right wheel speed difference ( ).

[0130] The speed of the right front wheel is adjusted to the current vehicle speed plus half of the left and right wheel speed difference ( ).

[0131] The left rear wheel speed remains at the current vehicle speed ( ).

[0132] The speed of the right rear wheel also remains at the current vehicle speed ( ).

[0133] In this way, the vehicle can prioritize maintaining the wheel speed difference between the left and right wheels on the front axle when turning, thereby effectively reducing the turning radius and ensuring the stability and controllability of the vehicle during the turning process.

[0134] For example, in a specific example, when the vehicle enters a control mode that requires a reduced turning radius, the system first collects and calculates parameters such as tire slip angle, steering wheel angle, steering wheel angle change rate, and lateral acceleration. Based on these parameters, the turning radius coefficient (K R ).

[0135] Assuming the initial turning radius is R, the system uses K R Adjust the initial turning radius. The adjusted turning radius is R*K R , so the left and right wheel speed difference =ΔV / K R At this time, the wheel speed distribution strategy is: the difference between the left and right wheel speeds is , and give priority to maintaining the wheel speed difference between the left and right wheels of the front axle. According to the calculated left and right wheel speed difference ( ), the system adjusts the wheel speed of each wheel:

[0136]

[0137]

[0138]

[0139]

[0140] Through the method of the present embodiment described above, the vehicle can intelligently adjust the turning radius, improve the vehicle's handling and stability, and provide the driver with a safer and more comfortable driving experience.

[0141] In some embodiments, the wheel speeds are allocated according to the acceleration coefficient and / or the turning radius coefficient, including:

[0142] According to the change of the acceleration coefficient and / or the turning radius coefficient, the wheel speed distribution strategy corresponding to the control target is updated, and the wheel speeds of the wheels are distributed using the updated wheel speed distribution strategy.

[0143] Specifically, the system monitors the vehicle's acceleration coefficient (K v ) and turning radius factor (K R ). These two coefficients reflect the current acceleration demand and turning demand of the vehicle respectively, and are the key parameters for the system to determine the wheel speed distribution.

[0144] Furthermore, when changes in the acceleration coefficient and / or turning radius coefficient are detected, the system will automatically update the corresponding wheel speed distribution strategy. For example, when the acceleration coefficient increases, the system will adjust the wheel speed distribution strategy so that more driving force is distributed to the front or rear wheels to achieve faster acceleration; when the turning radius coefficient increases, the system will adjust the speed difference between the left and right wheels to achieve a smaller turning radius.

[0145] Furthermore, the system calculates a new wheel speed distribution strategy based on the updated acceleration coefficient and / or turning radius coefficient. Specifically, the system adjusts the wheel speed of each wheel to make it more consistent with the current control target. For example:

[0146] When acceleration is prioritized, the system may increase the drive ratio of the rear wheels, thereby improving the vehicle's overall acceleration performance; when turning is prioritized, the system will increase the speed difference between the left and right wheels, allowing the vehicle to complete turns more flexibly.

[0147] Furthermore, the system uses the updated wheel speed distribution strategy to adjust the actual wheel speed of each wheel. For example:

[0148] If the acceleration coefficient is large, the system will adjust the speed difference between the front and rear wheels so that the vehicle can reach the required speed more quickly; if the turning radius coefficient is large, the system will adjust the speed difference between the left and right wheels to reduce the turning radius.

[0149] It should be noted that the "wheel speed" in some embodiments of the present application is a vector, that is, it includes not only the absolute value of the speed but also the direction of the wheel speed.

[0150] In some embodiments, the embodiment of the present application will also update the wheel speed distribution strategy corresponding to the control target according to the change of the acceleration coefficient and / or the turning radius coefficient. The specific contents are as follows:

[0151] Under the vehicle speed control target, query the pre-established first wheel speed distribution coefficient mapping relationship according to the acceleration coefficient to obtain the predetermined first wheel speed distribution coefficient;

[0152] Under the turning radius control target, a pre-established second wheel speed distribution coefficient mapping relationship is queried according to the turning radius coefficient to obtain a predetermined second wheel speed distribution coefficient;

[0153] The wheel speed distribution strategy under the vehicle speed control target is updated based on the wheel speed distribution strategy matching the first wheel speed distribution coefficient, or the wheel speed distribution strategy under the turning radius control target is updated based on the wheel speed distribution strategy matching the second wheel speed distribution coefficient.

[0154] First, the correlation coefficient changes (K v , K R ), the torque distribution strategy has the same control target. As long as the expected yaw moment is guaranteed, different distribution strategies can be used. Therefore, the distribution strategy needs to be limited in combination with the vehicle target change. λ is selected as the front axle torque distribution coefficient, and γ is the left wheel torque distribution coefficient.

[0155] Furthermore, the acceleration factor K v The value range is (1-ΔV / 4V) ~ (1+ΔV / 4V), and the average speed range is V-ΔV ~ V+ΔV. As shown in the following table, λ and γ increase with K v The torque distribution basis of the four wheels can be obtained according to λ and γ, that is, the greater the average speed, the greater the rear axle distribution ratio, the greater the right wheel distribution ratio, and the smaller the torque fluctuation. As shown in Table 1, Table 1 is a first wheel speed distribution coefficient mapping relationship table configured in some embodiments of the present application.

[0156] Table 1 Mapping relationship table of first wheel speed distribution coefficient

[0157]

[0158] Furthermore, the turning radius coefficient K R The value range is 0~1. R The smaller the difference, the greater the difference in left and right wheel speeds. The left and right wheels should be evenly distributed with the wheel speed difference, and the rear axle should also be allocated a certain proportion of the wheel speed difference to avoid the speed of a single wheel or a single axle exceeding the maximum wheel speed and slipping. The front axle should be maintained as the main wheel speed difference to ensure the turning radius of the vehicle. As shown in Table 2, Table 2 is a second wheel speed distribution coefficient mapping relationship table configured in some embodiments of the present application.

[0159] Table 2 Second wheel speed distribution coefficient mapping table

[0160]

[0161] Through the method of the above-mentioned embodiment, the present application targets the electronic differential control function, and according to the driver's driving intention and the vehicle state, enters the control target stage of increasing the target vehicle speed and reducing the turning radius according to different judgment conditions, can respond to the driving intention more highly and reduce the vehicle's turning radius, and try to transition to steering neutrality. At the same time, according to the different acceleration coefficients and turning radius coefficients in the same target, the values ​​of λ and γ are determined to obtain different torque distribution methods, thereby ensuring the stability and target characteristics of the vehicle to the greatest extent possible.

[0162] Furthermore, the embodiment of the present application will also establish an overall architecture of upper-level control and lower-level control. Figure 2 Schematic diagram of the overall architecture based on upper layer control and lower layer control provided by the embodiment of the present application. Figure 2 As shown, the schematic diagram of the overall architecture based on upper-level control and lower-level control may specifically include: electronic differential control is located in the lower-level control as a basic function; when turning radius control and vehicle speed control are not activated, the control target of the electronic differential control is the desired yaw moment of the vehicle; when turning radius control and vehicle speed control are activated, the control target of the electronic differential is updated to the turning radius control mode or the vehicle speed control mode.

[0163] In some embodiments, a judgment is made based on the current acceleration coefficient, turning radius coefficient, vehicle speed, and one or more conditions during the positive and negative speed switching of the wheel, and a corresponding speed control strategy is determined according to the judgment result, including:

[0164] When the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is less than the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the first speed difference threshold, it is determined to be the first speed control strategy;

[0165] When the turning radius coefficient is greater than the turning radius coefficient threshold, the acceleration coefficient is less than the acceleration coefficient threshold, and the vehicle speed is greater than or equal to the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the second speed difference threshold, it is determined to be the second speed control strategy;

[0166] When the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is greater than or equal to the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the third speed difference threshold, it is determined to be the third speed control strategy;

[0167] When the turning radius coefficient is greater than or equal to the turning radius coefficient threshold, the fourth speed control strategy is determined;

[0168] When the wheels of the vehicle are in the process of switching between positive and negative speeds, it is determined to be the fifth speed control strategy.

[0169] Specifically, when the control strategy in the upper-level control switches from turning radius to vehicle speed or from vehicle speed to turning radius, the following control strategy is formulated:

[0170] Speed ​​control strategy 1: When K R <0.5 and Kv<1, if the vehicle speed is <80km / h, when the control target is switched, the overall vehicle speed is relatively low and the sensitivity to the speed change of the vehicle is relatively high. Therefore, the filtering gradient should not be too large, and the speed difference ΔVc on the same wheel needs to be further determined. When ΔVc>0.3ΔV, the speed gradient limit should be increased in response to the speed change (which can be controlled by torque), and the maximum speed gradient is 0.3ΔV;

[0171] Speed ​​control strategy 2: When K R <0.5 and Kv<1, if the vehicle speed is ≥80km / h, when the control target is switched, the overall vehicle speed is relatively high, and the sensitivity to the speed change of the vehicle is not high, but there are certain requirements for vehicle stability. The filter gradient can be appropriately increased, and the speed difference ΔVc on the same wheel needs to be further determined. When ΔVc>0.5ΔV, the speed gradient limit should be increased in response to the speed change (which can be controlled by torque), and the maximum speed gradient is 0.5ΔV;

[0172] Speed ​​control strategy three: when K R <0.5 and Kv≥1, if the vehicle speed is <80km / h, when the control target is switched, the purpose is to increase the overall speed of the vehicle quickly, so the filter gradient can be increased. The speed difference ΔVc on the same wheel needs to be further determined. When ΔVc>ΔV, the speed gradient limit should be increased in response to the speed change (which can be controlled by torque), and the maximum speed gradient is ΔV;

[0173] Speed ​​control strategy 4: When K RWhen ≥0.5, when the control target is switched, the four-wheel speed can be directly switched to the speed required by the demand target, and the speed gradient is limited (can be controlled by torque), and the maximum speed gradient is 0.5ΔV;

[0174] Speed ​​control strategy five: During the switching process between positive and negative speeds of the four wheels, in order to ensure the smoothness of vehicle driving, the maximum speed gradient is 0.1ΔV.

[0175] In some embodiments, the speed control strategy is used to adjust the speed gradient of each wheel through torque control, including:

[0176] When it is determined to be the first speed control strategy, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the first speed gradient;

[0177] When it is determined that the second speed control strategy is used, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the second speed gradient;

[0178] When the third speed control strategy is determined, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the third speed gradient;

[0179] When it is determined that the fourth speed control strategy is used, the wheel speed of the vehicle is switched to the required target speed, and the maximum value of the speed gradient is limited to the fourth speed gradient;

[0180] When the fifth speed control strategy is determined, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the fifth speed gradient.

[0181] Specifically, speed control strategy 1: When the turning radius coefficient (K R ) is less than 0.5 and the acceleration coefficient (Kv) is less than 1, if the vehicle speed is less than 80 km / h.

[0182] The current wheel speed difference (ΔVc) is determined. If ΔVc is greater than 0.3 times the initial speed difference (ΔV), the speed gradient is limited to a maximum of 0.3ΔV through torque control to ensure vehicle stability at low speeds.

[0183] Speed ​​control strategy 2: When the turning radius coefficient (K R ) is less than 0.5 and the acceleration coefficient (Kv) is less than 1, if the vehicle speed is greater than or equal to 80 km / h.

[0184] The current wheel speed difference (ΔVc) is determined. If ΔVc is greater than 0.5 times the initial speed difference (ΔV), the speed gradient is limited to a maximum of 0.5ΔV through torque control to ensure vehicle stability at high speeds.

[0185] Speed ​​control strategy three: When the turning radius coefficient (K R ) is less than 0.5 and the acceleration coefficient (Kv) is greater than or equal to 1, if the vehicle speed is less than 80 km / h.

[0186] The current wheel speed difference (ΔVc) is determined. If ΔVc is greater than the initial speed difference (ΔV), the speed gradient is limited to the maximum ΔV through torque control to quickly increase the overall vehicle speed.

[0187] Speed ​​control strategy 4: When the turning radius coefficient (K R ) is greater than or equal to 0.5. Directly switch the four-wheel speed to the speed required by the target. The speed gradient is limited to a maximum of 0.5ΔV through torque control to ensure that the vehicle can respond quickly to different control targets.

[0188] Speed ​​control strategy 5: During the positive and negative speed switching of the four wheels, in order to ensure the smoothness of the vehicle's driving, the speed gradient is limited to a maximum of 0.1ΔV through torque control.

[0189] In actual applications, when the vehicle switches between different control objectives, such as switching from vehicle speed control to turning radius control, or from turning radius control to vehicle speed control, the system will adjust the speed of each wheel according to the above strategy. Specifically:

[0190] When the system detects that the current turning radius coefficient and acceleration coefficient meet the conditions of the first speed control strategy (K R <0.5 and K v <1, vehicle speed <80km / h), the wheel speed difference ΔVc will be determined, and the speed gradient will be limited to a maximum of 0.3ΔV through torque control, thereby ensuring a smooth speed change at low speeds.

[0191] If the vehicle is in high speed state (vehicle speed ≥ 80km / h) and meets the conditions of the second speed control strategy (K R <0.5 and K v <1), the system will appropriately increase the filter gradient and limit the speed gradient to a maximum of 0.5ΔV to ensure vehicle stability.

[0192] When the overall vehicle speed needs to be increased quickly, for example, the conditions of the third speed control strategy (K R <0.5 and K v ≥1, vehicle speed <80km / h), the system will limit the speed gradient to the maximum ΔV to achieve rapid acceleration.

[0193] When the fourth speed control strategy is applied (K R≥0.5), the system will directly switch to the target speed and limit the speed gradient to a maximum of 0.5ΔV.

[0194] Finally, when the vehicle is switching between positive and negative speeds of the four wheels (the fifth speed control strategy), the system will limit the speed gradient to a maximum of 0.1ΔV to ensure the smoothness of the vehicle's driving.

[0195] Through the method of the present embodiment described above, the system can effectively switch between different control targets, ensure the stability and responsiveness of the vehicle under various driving conditions, and provide a smoother and safer driving experience.

[0196] In some embodiments, the method further comprises:

[0197] When there are mutually exclusive conditions between different control targets and it is detected that the vehicle switches between different control targets, the current control target is released and another control target is activated;

[0198] In the absence of mutually exclusive conditions between different control objectives, the weight ratio of different control objectives is determined according to the values ​​of the turning radius coefficient and the acceleration coefficient. When different control objectives are activated, the weight ratio is used to perform weighted summation on the wheel speed required for the turning radius control objective and the wheel speed required for the vehicle speed control objective to obtain the final wheel speed of each wheel.

[0199] Specifically, the system first determines whether there is a conditional mutual exclusion between the current control targets. When there is a conditional mutual exclusion, the system monitors the vehicle's state parameters, and when it detects that the vehicle needs to switch between different control targets, it releases the current control target and activates another control target. For example, when the vehicle needs to switch from speed control to turning radius control, the system will first release speed control and then activate turning radius control to ensure that only one control target is activated.

[0200] Furthermore, the weighted summation of non-mutually exclusive control objectives is processed as follows: When the system determines that different control objectives do not have mutually exclusive conditions, the system will calculate the weighted summation of non-mutually exclusive control objectives according to the turning radius coefficient (K R ) and the acceleration factor (K v ) determines the weight ratio (λ) of different control objectives.

[0201] The allocation principle is: | K R The larger the -1| is, the greater the demand for turning radius control is, and the greater the weight of turning radius control is; v The larger the -1| is, the greater the demand for speed control is, and the greater the weight of speed control is.

[0202] Furthermore, the required wheel speed for the turning radius control target is set to V R, the required wheel speed of the vehicle speed control target is VV. When both control targets are activated, the system uses the weight ratio (λ) to control V R and V V Perform weighted summation to calculate the final wheel speed (Vi) of each wheel. The specific calculation formula is: V i = λV R + (1-λ) V V , where i represents each wheel (front left wheel, front right wheel, rear left wheel, rear right wheel).

[0203] As shown in Table 3, the corresponding K R , K v The value of corresponds to a lambda value.

[0204] Table 3 Turning radius coefficient (K R ) and the acceleration factor (K v ) and weight ratio (λ)

[0205]

[0206] In actual applications, when the vehicle is in complex driving conditions that require simultaneous consideration of vehicle speed and turning radius control, the system will automatically judge and handle these two situations.

[0207] (1) Mutually exclusive conditions:

[0208] For example, when the vehicle is driving on a straight road, speed control is required, while when entering a curve, turning radius control is required. When the system detects a curve condition, it will first release the current speed control and then activate the turning radius control to ensure the stability of the vehicle in the curve.

[0209] (2) When the conditions are not mutually exclusive:

[0210] In some complex driving scenarios, such as when accelerating and turning at the same time, the system will adjust the turning radius according to the current turning radius coefficient (K R ) and the acceleration factor (K v ), determine the weight ratio (λ) between the two.

[0211] Assume that the current K R A larger value indicates a higher turning demand, while K v A smaller value indicates a lower acceleration demand, and the system will give a higher weight to turning control.

[0212] When the system calculates the final wheel speed of each wheel, V R and V V A weighted sum is performed to ensure that the vehicle can turn safely and smoothly while accelerating.

[0213] Through the method of the present embodiment described above, the system can effectively handle mutually exclusive and non-mutually exclusive situations between different control targets, ensure the stability and safety of the vehicle under various driving conditions, and improve the overall driving experience.

[0214] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0215] Figure 3 Schematic diagram of the structure of the speed control device based on the control target provided in the embodiment of the present application. Figure 3 As shown, the speed control device based on the control target includes:

[0216] The determination module 301 is configured to collect the driver input signal and the vehicle state parameter, and determine the control target of the vehicle based on the driver input signal and the vehicle state parameter;

[0217] The first wheel speed adjustment module 302 is configured to calculate the acceleration coefficient according to the driver input signal and the vehicle state parameter when the control target is determined to be vehicle speed control, and to adjust the wheel speed based on the acceleration coefficient and the corresponding wheel speed control strategy;

[0218] The second wheel speed adjustment module 303 is configured to calculate the turning radius coefficient according to the vehicle state parameter when the control target is determined to be turning radius control, and to adjust the wheel speed based on the turning radius coefficient and the corresponding wheel speed control strategy;

[0219] The speed adjustment module 304 is configured to make a judgment based on the vehicle's current acceleration coefficient, turning radius coefficient, vehicle speed, and one or more conditions during the switching process of the positive and negative speeds of the wheels when the vehicle switches between different control targets, and determine a corresponding speed control strategy based on the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the wheel speed to the target speed.

[0220] In some embodiments, Figure 3 The determination module 301 determines whether the vehicle meets the preset target conditions for vehicle speed control through the pedal opening, the pedal opening change rate, the vehicle acceleration mode and the available power of the whole vehicle; wherein the pedal opening, the pedal opening change rate and the available power of the whole vehicle are compared with the corresponding thresholds respectively, and according to the comparison result and the vehicle acceleration mode, it is determined whether the control target of the vehicle is acceleration control or deceleration control.

[0221] In some embodiments, Figure 3The determination module 301 determines whether the vehicle meets the preset turning radius control target conditions according to the tire slip angle, the steering wheel angle, the steering wheel angle change rate and the lateral acceleration; wherein, when the tire slip angle, the steering wheel angle, the steering wheel angle change rate and the lateral acceleration are all greater than the corresponding thresholds, it is determined that the control target of the vehicle is to reduce the turning radius.

[0222] In some embodiments, Figure 3 The first wheel speed adjustment module 302 determines the acceleration coefficient according to a pre-established acceleration coefficient mapping relationship using the vehicle's current pedal opening, pedal opening change rate and vehicle available power when the vehicle's control target is acceleration control or deceleration control; wherein the value of the acceleration coefficient is positively correlated with the values ​​of the pedal opening, pedal opening change rate and vehicle available power.

[0223] In some embodiments, Figure 3 The first wheel speed adjustment module 302 calculates the target average vehicle speed according to the acceleration coefficient, determines the wheel speed corresponding to each wheel according to the target average vehicle speed and the current vehicle speed and the average vehicle speed, and distributes the wheel speed to the corresponding wheel.

[0224] In some embodiments, Figure 3 When the control target of the vehicle is to reduce the turning radius, the second wheel speed adjustment module 303 uses the vehicle's current tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration to determine the turning radius coefficient according to a pre-established turning radius coefficient mapping relationship; wherein the value of the turning radius coefficient is negatively correlated with the values ​​of the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration.

[0225] In some embodiments, Figure 3 The second wheel speed adjustment module 303 adjusts the initial turning radius using the turning radius coefficient to obtain an adjusted turning radius, calculates the left and right wheel speed difference according to the turning radius coefficient, determines the wheel speed corresponding to each wheel according to the left and right wheel speed difference and the current vehicle speed, and distributes the wheel speed to the corresponding wheel.

[0226] In some embodiments, Figure 3The speed adjustment module 304 obtains the speed difference on the same wheel when the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is less than the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, and when the speed difference is greater than the first speed difference threshold, it is determined to be the first speed control strategy; when the turning radius coefficient is greater than the turning radius coefficient threshold, the acceleration coefficient is less than the acceleration coefficient threshold, and the vehicle speed is greater than or equal to the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the second speed difference threshold, it is determined to be the second speed control strategy; when the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is greater than or equal to the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the third speed difference threshold, it is determined to be the third speed control strategy; when the turning radius coefficient is greater than or equal to the turning radius coefficient threshold, it is determined to be the fourth speed control strategy; when the wheels of the vehicle are in the process of switching between positive and negative speeds, it is determined to be the fifth speed control strategy.

[0227] In some embodiments, Figure 3 When the speed adjustment module 304 is judged as the first speed control strategy, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the first speed gradient; when it is judged as the second speed control strategy, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the second speed gradient; when it is judged as the third speed control strategy, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the third speed gradient; when it is judged as the fourth speed control strategy, the wheel speed of the vehicle is switched to the required target speed, and the maximum value of the speed gradient is limited to the fourth speed gradient; when it is judged as the fifth speed control strategy, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the fifth speed gradient.

[0228] In some embodiments, Figure 3 The speed adjustment module 304 releases the current control target and activates another control target when there is conditional mutual exclusion between different control targets and it is detected that the vehicle switches between different control targets. When there is no conditional mutual exclusion between different control targets, the weight ratio of different control targets is determined according to the values ​​of the turning radius coefficient and the acceleration coefficient. When all different control targets are activated, the weight ratio is used to perform weighted summation on the wheel speed required for the turning radius control target and the wheel speed required for the vehicle speed control target to obtain the final wheel speed of each wheel.

[0229] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0230] An embodiment of the present application also provides a new energy vehicle, including a vehicle controller, a motor controller, a drive motor and a transmission system; the vehicle controller is used to implement the above-mentioned wheel speed distribution method based on multi-objective control, so as to adjust the wheel speed of each wheel using the wheel speed distribution method, and send the wheel speed of each wheel to the motor controller; the motor controller is used to control the wheel speed of the drive motor through the transmission system according to the wheel speed of each wheel.

[0231] Figure 4 Schematic diagram of the structure of the electronic device 4 provided in the embodiment of the present application. Figure 4 As shown, the electronic device 4 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 401 executes the computer program 403, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0232] Exemplarily, the computer program 403 may be divided into one or more modules / units, which are stored in the memory 402 and executed by the processor 401 to complete the present application. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 403 in the electronic device 4.

[0233] The electronic device 4 may be a desktop computer, a notebook, a PDA, a cloud server, or other electronic device. The electronic device 4 may include, but is not limited to, a processor 401 and a memory 402. Those skilled in the art will appreciate that Figure 4 It is only an example of the electronic device 4 and does not constitute a limitation of the electronic device 4. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0234] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0235] The memory 402 may be an internal storage unit of the electronic device 4, for example, a hard disk or memory of the electronic device 4. The memory 402 may also be an external storage device of the electronic device 4, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 4. Further, the memory 402 may also include both an internal storage unit and an external storage device of the electronic device 4. The memory 402 is used to store computer programs and other programs and data required by the electronic device. The memory 402 may also be used to temporarily store data that has been output or is to be output.

[0236] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0237] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0238] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0239] In the embodiments provided in the present application, it should be understood that the disclosed devices / computer equipment and methods can be implemented in other ways. For example, the device / computer equipment embodiments described above are only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. Multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0240] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0241] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0242] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. The computer program may include computer program code, which may be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0243] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A speed control method based on a control target, characterized in that: include: collecting driver input signals and vehicle state parameters, and determining a vehicle control target based on the driver input signals and vehicle state parameters; When it is determined that the control target is vehicle speed control, an acceleration coefficient is calculated according to the driver input signal and the vehicle state parameter, and the wheel speed is adjusted based on the acceleration coefficient and the corresponding wheel speed control strategy; When it is determined that the control target is turning radius control, a turning radius coefficient is calculated according to the vehicle state parameter, and the wheel speed is adjusted based on the turning radius coefficient and a corresponding wheel speed control strategy; When the vehicle switches between different control targets, a judgment is made based on the current acceleration coefficient, turning radius coefficient, vehicle speed, and one or more conditions in the process of switching between positive and negative speeds of the wheels, and a corresponding speed control strategy is determined according to the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheels through torque control so as to adjust the speed of the wheels to the target speed; Wherein, the method further comprises: When there are mutually exclusive conditions between different control targets and it is detected that the vehicle switches between different control targets, the current control target is released and another control target is activated; In the absence of mutually exclusive conditions between different control targets, the weight ratio of different control targets is determined according to the values ​​of the turning radius coefficient and the acceleration coefficient. When all different control targets are activated, the weight ratio is used to perform weighted summation on the wheel speed required for the turning radius control target and the wheel speed required for the vehicle speed control target to obtain the final wheel speed of each wheel.

2. The method according to claim 1, characterized in that: The determining of the control target of the vehicle based on the driver input signal and the vehicle state parameter comprises: Determine whether the vehicle meets the preset vehicle speed control target conditions through the pedal opening, pedal opening change rate, vehicle acceleration mode and vehicle available power; The pedal opening, the pedal opening change rate and the vehicle available power are compared with corresponding thresholds respectively, and according to the comparison result and the vehicle acceleration mode, it is determined whether the vehicle control target is acceleration control or deceleration control.

3. The method according to claim 1, characterized in that The determining of the control target of the vehicle based on the driver input signal and the vehicle state parameter comprises: According to the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration, it is judged whether the vehicle meets the preset turning radius control target conditions; wherein, when the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration are all greater than corresponding thresholds, it is judged that the control target of the vehicle is to reduce the turning radius.

4. The method according to claim 2, characterized in that: When it is determined that the control target is vehicle speed control, the acceleration coefficient is calculated according to the driver input signal and the vehicle state parameter, including: When the control target of the vehicle is acceleration control or deceleration control, the acceleration coefficient is determined according to a pre-established acceleration coefficient mapping relationship using the current pedal opening, pedal opening change rate and vehicle available power of the vehicle; The value of the acceleration coefficient is positively correlated with the pedal opening, the pedal opening change rate and the value of the available power of the vehicle.

5. The method according to claim 1, characterized in that The wheel speed adjustment based on the acceleration coefficient and the corresponding wheel speed control strategy includes: The target average vehicle speed is calculated according to the acceleration coefficient, the wheel speed corresponding to each wheel is determined according to the target average vehicle speed and the current vehicle speed and the average vehicle speed of the vehicle, and the wheel speed is allocated to the corresponding wheel.

6. The method according to claim 3, characterized in that When it is determined that the control target is turning radius control, calculating the turning radius coefficient according to the vehicle state parameter includes: When the control target of the vehicle is to reduce the turning radius, the turning radius coefficient is determined according to a pre-established turning radius coefficient mapping relationship using the current tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration of the vehicle; The turning radius coefficient is negatively correlated with the tire slip angle, steering wheel angle, steering wheel angle change rate and lateral acceleration.

7. The method according to claim 6, characterized in that The wheel speed adjustment based on the turning radius coefficient and the corresponding wheel speed control strategy includes: The initial turning radius is adjusted using the turning radius coefficient to obtain an adjusted turning radius, the left and right wheel speed difference is calculated based on the turning radius coefficient, the wheel speed corresponding to each wheel is determined based on the left and right wheel speed difference and the current speed of the vehicle, and the wheel speed is allocated to the corresponding wheel.

8. The method according to claim 1, characterized in that The method of judging based on one or more conditions during the switching process of the vehicle's current acceleration coefficient, turning radius coefficient, vehicle speed, and positive and negative speeds of the wheels, and determining a corresponding speed control strategy according to the judgment result includes: When the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is less than the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the first speed difference threshold, it is determined to be the first speed control strategy; When the turning radius coefficient is greater than a turning radius coefficient threshold, the acceleration coefficient is less than an acceleration coefficient threshold, and the vehicle speed is greater than or equal to a vehicle speed threshold, obtaining a speed difference on the same wheel, and when the speed difference is greater than a second speed difference threshold, determining that the second speed control strategy is in place; When the turning radius coefficient is less than the turning radius coefficient threshold, the acceleration coefficient is greater than or equal to the acceleration coefficient threshold, and the vehicle speed is less than the vehicle speed threshold, the speed difference on the same wheel is obtained, and when the speed difference is greater than the third speed difference threshold, it is determined to be the third speed control strategy; When the turning radius coefficient is greater than or equal to the turning radius coefficient threshold, determining to adopt the fourth speed control strategy; When the wheels of the vehicle are in the process of switching between positive and negative speeds, it is determined to be the fifth speed control strategy.

9. The method according to claim 8, characterized in that The speed control strategy is used to adjust the speed gradient of each wheel through torque control, including: When it is determined that the first speed control strategy is used, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the first speed gradient; When it is determined that the second speed control strategy is used, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the second speed gradient; When the third speed control strategy is determined, a speed gradient limit is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the third speed gradient; When it is determined that the fourth speed control strategy is used, the wheel speed of the vehicle is switched to the required target speed, and the maximum value of the speed gradient is limited to the fourth speed gradient; When the fifth speed control strategy is determined, a speed gradient limitation is added to the speed change of the wheel through torque control, and the maximum value of the speed gradient is limited to the fifth speed gradient.

10. A speed control device based on a control target, characterized in that: include: a determination module configured to collect a driver input signal and a vehicle state parameter, and determine a control target of the vehicle based on the driver input signal and the vehicle state parameter; a first wheel speed adjustment module, configured to calculate an acceleration coefficient according to the driver input signal and the vehicle state parameter when it is determined that the control target is vehicle speed control, and to adjust the wheel speed based on the acceleration coefficient and a corresponding wheel speed control strategy; a second wheel speed adjustment module, configured to calculate a turning radius coefficient according to the vehicle state parameter when it is determined that the control target is turning radius control, and to adjust the wheel speed based on the turning radius coefficient and a corresponding wheel speed control strategy; a speed adjustment module, configured to make a judgment based on one or more conditions in the process of switching between positive and negative speeds of the vehicle, when the vehicle switches between different control targets, and determine a corresponding speed control strategy according to the judgment result, wherein the speed control strategy is used to adjust the speed gradient of the wheel through torque control so as to adjust the speed of the wheel to the target speed; Among them, the speed adjustment module is used to release the current control target and activate another control target when there is conditional mutual exclusion between different control targets and it is detected that the vehicle switches between different control targets; when there is no conditional mutual exclusion between different control targets, the weight ratio of different control targets is determined according to the values ​​of the turning radius coefficient and the acceleration coefficient. When different control targets are all activated, the weight ratio is used to perform weighted summation on the wheel speed required for the turning radius control target and the wheel speed required for the vehicle speed control target to obtain the final wheel speed of each wheel.

11. A new energy vehicle, characterized in that: Including controller, power system and transmission system; The controller is used to implement the steps of the method according to any one of claims 1 to 9, so as to adjust the speed gradient of the wheel through torque control using a speed control strategy, and send the target speed of the wheel to the power system; The power system is used to control the speed of the drive motor through the transmission system according to the target speed.

Images