A method, device, electronic equipment, and storage medium for controlling vehicle cornering.

Abstract

This application relates to the field of vehicle technology and discloses a control method, device, electronic equipment, and storage medium for vehicle cornering. The control method includes: when the vehicle is in a cornering state, under conditions where energy recovery is limited and the vehicle's lateral acceleration is greater than a preset lateral acceleration, determining an initial recovery torque and a traction torque based on the vehicle's operating parameters to determine a desired recovery torque; if the value of the desired recovery torque is greater than the value of a threshold recovery torque, determining a compensation torque based on the desired recovery torque and the threshold recovery torque, and determining a threshold compensation torque based on the ground adhesion coefficient; determining a target compensation torque based on the compensation torque and the threshold compensation torque, controlling the motor to output a first composite torque, and braking the wheels based on the target compensation torque; the first composite torque is the sum of the threshold recovery torque and the traction torque. This application can ensure that the vehicle safely and smoothly passes through large-curvature curves.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a control method, device, electronic equipment, and storage medium for vehicle cornering. Background Technology

[0002] To improve the driving range of new energy vehicles, an energy recovery system is equipped on their power batteries, which enables the vehicle to convert kinetic energy into electrical energy for storage during coasting or braking.

[0003] When a vehicle is in a state of limited energy recovery, the energy recovery system cannot provide sufficient recovery torque, resulting in a less than expected braking effect. At the same time, when a vehicle is in a state of limited energy recovery and is in a high-curvature curve (i.e., the vehicle's lateral acceleration reaches a threshold), it is necessary to reduce the cornering speed while ensuring vehicle stability to allow the vehicle to safely navigate the curve. Summary of the Invention

[0004] In view of the above problems, this application provides a vehicle cornering control method, device, electronic device and storage medium. When the vehicle is in a state of limited energy recovery and the lateral acceleration is greater than the preset lateral acceleration while cornering, the method simultaneously considers the braking torque and traction torque, and controls the motor and wheels to perform coordinated braking, so as to ensure the vehicle braking effect while taking into account the vehicle's cornering safety and power requirements.

[0005] According to one aspect of this application, a control method is provided, the control method comprising: when a vehicle is in a cornering state, and the vehicle is in an energy recovery limited state and the lateral acceleration of the vehicle is greater than a preset lateral acceleration, determining an initial recovery torque and a traction torque based on the vehicle's operating parameters to determine a desired recovery torque; if the value of the desired recovery torque is greater than the value of a threshold recovery torque, determining a compensation torque based on the desired recovery torque and the threshold recovery torque, and determining a threshold compensation torque based on the ground adhesion coefficient; determining a target compensation torque based on the compensation torque and the threshold compensation torque, controlling the motor to output a first composite torque, and braking the wheels based on the target compensation torque; the first composite torque is the sum of the threshold recovery torque and the traction torque.

[0006] In one alternative approach, determining the threshold compensation torque based on the ground adhesion coefficient includes: determining a threshold braking torque based on the ground adhesion coefficient, the mass of the vehicle, and the wheel radius; and using the quotient between the threshold charging power of the power battery and the angular velocity of the motor as the threshold recovery torque; and determining the difference between the threshold braking torque and the threshold recovery torque as the threshold compensation torque.

[0007] In one alternative approach, braking the wheel based on the target compensation torque includes: calculating the frictional force between the brake pad and the brake disc based on the target compensation torque and the effective radius of the brake disc; and calculating the braking pressure of the brake wheel cylinder based on the frictional force and coefficient of friction between the brake discs and the hydraulic area of ​​the brake wheel cylinder, so as to brake the wheel based on the braking pressure.

[0008] In one alternative approach, the control method further includes: if the vehicle speed is greater than a preset vehicle speed, the accelerator pedal opening is less than a preset first opening, the brake pedal opening is less than a preset second opening, and the power battery temperature is less than a preset temperature and / or the remaining charge is greater than a preset remaining charge, then the vehicle is determined to be in an energy recovery limited state.

[0009] In one optional approach, determining the target compensation torque based on the compensation torque and the threshold compensation torque includes: if the value of the compensation torque is greater than the value of the threshold compensation torque, then the threshold compensation torque is determined as the target compensation torque; if the value of the compensation torque is less than or equal to the value of the threshold compensation torque, then the compensation torque is determined as the target compensation torque.

[0010] In one optional approach, the operating parameters include the vehicle's driving mode, vehicle speed, accelerator pedal opening, battery temperature, and remaining charge. Determining the initial recovery torque and traction torque based on the vehicle's operating parameters to determine the desired recovery torque includes: determining a target MAP based on the driving mode, and determining the initial recovery torque based on the vehicle speed, accelerator pedal opening, and the target MAP; determining the traction torque based on the vehicle speed and lateral acceleration, and using the sum of the initial recovery torque and the traction torque as the desired recovery torque.

[0011] In an optional embodiment, the control method further includes: if the value of the desired recovery torque is less than or equal to the value of the threshold recovery torque, then the sum of the desired recovery torque and the traction torque is used as a second composite torque, and the motor is controlled to output the second composite torque.

[0012] According to another aspect of this application, a vehicle cornering control device is provided. The control device includes: a desired recovery torque determination module, configured to determine an initial recovery torque and a traction torque based on the vehicle's operating parameters when the vehicle is in a cornering state, under conditions where energy recovery is limited and the vehicle's lateral acceleration is greater than a preset lateral acceleration, thereby determining a desired recovery torque; a compensation torque determination module, configured to determine a compensation torque based on the desired recovery torque and the threshold recovery torque if the value of the desired recovery torque is greater than the value of the threshold recovery torque, and to determine a threshold compensation torque based on the ground adhesion coefficient; and a control module, configured to determine a target compensation torque based on the compensation torque and the threshold compensation torque, control the motor to output a first composite torque, and brake the wheels based on the target compensation torque; wherein the first composite torque is the sum of the threshold recovery torque and the traction torque.

[0013] According to one aspect of this application, an electronic device is provided, comprising: a controller; and a memory for storing one or more programs, which, when executed by the controller, perform the control method described above.

[0014] According to one aspect of this application, a computer-readable storage medium is also provided, on which computer-readable instructions are stored, which, when executed by a computer's processor, cause the computer to perform the control method described above.

[0015] According to one aspect of this application, a computer program product or computer program is also provided, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the control method described above.

[0016] This application, when a vehicle is cornering, under conditions of limited energy recovery, and with lateral acceleration exceeding a preset lateral acceleration, determines the initial recovery torque and the traction torque required for cornering by combining vehicle operating parameters. This determines the desired recovery torque. If the desired recovery torque exceeds a threshold recovery torque, a target compensation torque is determined based on the compensation torque and the threshold compensation torque. The motor outputs a first composite torque (the sum of the threshold recovery torque and the traction torque), causing the motor to output negative torque according to the first composite torque to produce a braking effect on the vehicle. Based on the target compensation torque, the wheels are braked (e.g., using a hydraulic braking system or electronic parking brake actuator to apply a mechanical braking force equivalent to the target compensation torque to the rear wheel on the inside of the turn) to reduce the cornering speed. This application, while considering the traction torque required for cornering, coordinates the control of the vehicle for both motor braking and mechanical braking to ensure effective braking while balancing the vehicle's safety and power requirements for cornering, enabling the vehicle to corner safely and smoothly.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0019] Figure 1 This is a schematic flowchart illustrating a vehicle cornering control method according to an exemplary embodiment of this application.

[0020] Figure 2 This is a schematic diagram illustrating an application scenario of the vehicle cornering control method described in this application.

[0021] Figure 3 This is a schematic diagram of the structure of a vehicle cornering control device shown in an exemplary embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the structure of a computer system for an electronic device illustrated in an exemplary embodiment of this application. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0025] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0026] In this application, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0027] As described in the background section, if a vehicle is in a state of limited energy recovery, the energy recovery system cannot provide sufficient recovery torque, resulting in a less than expected braking effect. Meanwhile, when a vehicle is in a state of limited energy recovery and is on a high-curvature curve (i.e., the vehicle's lateral acceleration reaches a threshold), it is necessary to reduce cornering speed while maintaining vehicle stability to ensure safe cornering.

[0028] This application finds that in cornering scenarios, large-curvature curves (i.e., sharp or steep curves) are identified by the vehicle's lateral acceleration. In large-curvature curves, vehicles experience significant centrifugal forces, demanding high stability during cornering. Furthermore, if the vehicle is identified as being in a state of limited energy recovery, relying solely on electric motor braking may result in insufficient braking performance due to the motor failing to provide the driver's or system's desired recovery torque, thus failing to meet deceleration requirements. If mechanical braking is used in conjunction, improper braking force distribution or over-braking may also affect the vehicle's cornering stability. Especially on low-traction surfaces, excessive braking force can easily cause wheel lock-up or skidding, leading to safety accidents.

[0029] To address this, one aspect of this application provides a vehicle cornering control method. When a vehicle is navigating a curve with a large curvature and energy recovery is limited, this method intelligently coordinates electric motor power and mechanical braking force, employing a comprehensive control strategy that satisfies deceleration requirements while prioritizing lateral stability. Please refer to the details below. Figure 1 , Figure 1 This is a schematic flowchart illustrating a vehicle cornering control method according to an exemplary embodiment of this application. The control method includes at least steps S110 to S130, which are described in detail below:

[0030] S110: When the vehicle is in a cornering state, under the condition that the vehicle is in a limited energy recovery state and the vehicle's lateral acceleration is greater than the preset lateral acceleration, the initial recovery torque and traction torque are determined according to the vehicle's operating parameters, so as to determine the expected recovery torque.

[0031] The cornering state is a state in which a vehicle has the intention to corner and has already performed the corresponding cornering driving operation.

[0032] The energy recovery limitation state can be determined based on the relevant operating parameters of the vehicle, including but not limited to the temperature and remaining charge of the power battery.

[0033] When the power battery is in low-temperature conditions (e.g., -25°C and below) or high-SOC (State of Charge, remaining charge), such as SOC ≥ 95%, the battery management system will limit the energy recovery power of the power battery to prevent overcharging risks. In this situation, if the vehicle enters energy recovery mode, the limited energy recovery power of the power battery will result in a restricted energy recovery state. Energy recovery mode refers to the condition where the vehicle converts kinetic energy into electrical energy during braking and / or coasting.

[0034] Here is an example of the limited recovery power state under coasting energy recovery conditions: if the vehicle speed is greater than the preset vehicle speed, the accelerator pedal opening is less than the preset first opening, and the brake pedal opening is less than the preset second opening, and the power battery temperature is less than the preset temperature and / or the remaining charge is greater than the preset remaining charge, then the vehicle is determined to be in a limited energy recovery state.

[0035] If the vehicle speed is greater than a preset speed, the accelerator pedal opening is less than a preset first opening, and the brake pedal opening is less than a preset second opening, then the vehicle is determined to be in coasting energy recovery mode. Here, the preset speed, preset first opening, and preset second opening are preset parameters adaptively adjusted according to the scenario; both preset first and preset second openings are opening values ​​approaching zero. If the battery temperature is less than a preset temperature, and / or the remaining charge is greater than a preset remaining charge, then the power battery is determined to be in a state of limited recovery power.

[0036] Specifically, if the current vehicle speed is greater than a preset speed (e.g., 8 to 10 km / h), it indicates that the vehicle is in motion. The preset speed can be understood as the minimum speed requirement for the vehicle to perform energy recovery. If the vehicle speed is too low (e.g., below 8 to 10 km / h), the motor's energy recovery efficiency is also low, and the vehicle will usually exit the energy recovery mode to avoid jerking. If the accelerator pedal opening is less than a preset first opening (e.g., 5%), it indicates that the driver has completely released the accelerator pedal, indicating that the driver intends to decelerate. If the brake pedal opening is less than a preset second opening (e.g., BrakePedalPress = Not Pressed < 1 MPa), it indicates that the driver has not actively requested mechanical braking. When these three conditions are met, the vehicle is determined to be in coasting energy recovery mode.

[0037] If the current battery temperature is lower than the preset temperature (e.g., -10℃), it indicates that the current battery temperature is extremely low, affecting the normal use of the power battery and the vehicle's energy recovery function. If the current remaining charge is greater than the preset remaining charge (e.g., 95%), it indicates that the power battery has sufficient charge and does not require additional energy recovery for charging. If either of these two conditions is met, the power battery is determined to be in a state of limited regenerative power.

[0038] It should be noted that the limited energy recovery power of the power battery is only one of the reasons why a vehicle is in a state of limited energy recovery. There are other situations known to those skilled in the art, which will not be discussed here.

[0039] Lateral acceleration is the acceleration directed towards the center of the turn during a vehicle's cornering motion. It is provided by the lateral friction force (i.e., lateral force) exerted by the ground on the tires. The magnitude of lateral acceleration depends on the vehicle's speed and the radius of curvature of the curve in which the vehicle is located. For example, a y =V 2 / R0; where a y R represents lateral acceleration, V represents vehicle speed, and R0 represents radius of curvature.

[0040] The following is an example of how to determine the initial recovery torque and traction torque based on the vehicle's operating parameters in order to determine the desired recovery torque; wherein, the operating parameters include the vehicle's driving mode, vehicle speed and accelerator pedal opening, power battery temperature and remaining charge.

[0041] For example, a target MAP (a preset MAP corresponding to the vehicle's current driving mode, a pre-calibrated and stored two-dimensional chart data structure used to map the ideal initial recovery torque output value under specific operating conditions; that is, the preset MAP reflects the mapping relationship between vehicle speed, accelerator pedal opening, and initial recovery torque) is determined based on the driving mode. The initial recovery torque is then determined based on the vehicle speed, accelerator pedal opening, and the target MAP. The traction torque is determined based on the vehicle speed and lateral acceleration, and the sum of the initial recovery torque and the traction torque is taken as the expected recovery torque. Clearly, the expected recovery torque is the desired torque value that considers the traction torque required for vehicle cornering. Here, the traction torque is not the traditional driving acceleration torque, but rather the adjusted torque applied to the motor to maintain the vehicle's cornering stability. This torque is essentially a virtual control quantity used to compensate for the risk of decreased tire grip and center of gravity shift caused by large lateral acceleration. The traction torque is determined by looking up a table: The vehicle speed and lateral acceleration are matched with the preset vehicle speed (parameter corresponding to the horizontal axis coordinate) and preset lateral acceleration (parameter corresponding to the vertical axis coordinate) in the traction torque MAP table, respectively. The working point (coordinate point) where both are successfully matched is determined, and the preset traction torque stored at the working point is used as the traction torque obtained by looking up the table.

[0042] The traction torque MAP table is constructed as follows: A two-dimensional MAP table (i.e., the traction torque MAP table) is built with a preset vehicle speed as the horizontal axis and a preset lateral acceleration as the vertical axis. It internally stores the preset traction torque corresponding to each operating condition point. The direction of the traction torque is generally the same as the vehicle's direction of travel, while the initial recovery torque and the desired recovery torque are generally opposite to the vehicle's direction of travel. The desired recovery torque is the recovery torque corresponding to the regenerative braking force that the vehicle system expects to obtain under the current operating condition.

[0043] This example meticulously categorizes vehicle driving modes, configuring separate preset MAP maps for each mode. The target MAP map is the preset MAP map corresponding to the vehicle's current driving mode. The horizontal axis of the preset MAP map is typically vehicle speed, and the vertical axis is accelerator pedal opening. Each coordinate point in the preset MAP map stores a corresponding torque suggestion value. Preset MAP maps can be obtained based on bench tests, real-vehicle road tests, and simulation optimization, and independent datasets are established for different driving modes. For example, ECO mode corresponds to a MAP map with a high recovery tendency, while SPORT mode corresponds to a MAP map with a low recovery tendency or even close to zero recovery. In this example, vehicle speed and accelerator pedal opening are used as the corresponding input parameters. The target MAP map is input to determine the target coordinate point that matches the input parameters. That is, the horizontal axis of the target coordinate point (representing the dimension of the preset vehicle speed) is the input vehicle speed, and the vertical axis (representing the dimension of the preset accelerator pedal opening) is the input accelerator pedal opening. The preset torque value stored in the target coordinate point is used as the initial recovery torque. Here, the initial recovery torque can be understood as the expected recovery torque during straight-line driving, i.e., a parameter that does not need to consider the traction torque required for turning.

[0044] For example, the vehicle speed and accelerator pedal opening are matched with preset vehicle speed and preset accelerator pedal opening in the target MAP, respectively; the same preset torque corresponding to the successfully matched preset vehicle speed and preset accelerator pedal opening is used as the initial recovery torque. The target MAP is a two-dimensional coordinate graph, where the preset vehicle speed and preset accelerator pedal opening are parameters represented by two different coordinate axes in the target MAP. For example, the horizontal axis represents the corresponding preset vehicle speed, and the vertical axis represents the corresponding preset accelerator pedal opening.

[0045] Specifically, the vehicle speed and accelerator pedal opening are input into the target MAP map to determine the successfully matched preset vehicle speed and preset accelerator pedal opening. The target coordinate point (two-dimensional coordinate point, with coordinate parameters in two dimensions, namely the preset vehicle speed and preset accelerator pedal opening) is then determined from the target MAP map. The target coordinate point corresponds to a preset torque, and the preset torque corresponding to the target coordinate point is used as the initial recovery torque.

[0046] S120: If the value of the expected recovery torque is greater than the value of the threshold recovery torque, the compensation torque is determined based on the expected recovery torque and the threshold recovery torque, and the threshold compensation torque is determined based on the ground adhesion coefficient.

[0047] The value of the expected recovered torque can be understood as the absolute value of the expected recovered torque. Similarly, the value of the threshold recovered torque can be understood as the absolute value of the threshold recovered torque.

[0048] Threshold regenerative torque is the maximum regenerative braking torque that the motor can provide under the current operating conditions. Threshold regenerative torque equals the quotient between the threshold charging power of the power battery and the angular velocity of the motor; where threshold charging power is the maximum threshold charging power allowed by the power battery under the current operating conditions. If the desired regenerative torque is greater than the threshold regenerative torque, it indicates that even if the motor outputs its maximum regenerative torque, it still cannot meet all the torque required for vehicle braking, and mechanical braking of the wheels is necessary to ensure good braking performance. If the vehicle is in a state of limited energy recovery, the desired regenerative torque can be determined based on operating parameters such as vehicle speed and accelerator pedal opening. For example, there are corresponding preset mapping relationships between vehicle speed and accelerator pedal opening and regenerative torque. The same preset regenerative torque corresponding to vehicle speed and accelerator pedal opening is used as the desired regenerative torque. Simultaneously, the threshold regenerative torque is determined based on the battery's threshold charging power and the motor's angular velocity.

[0049] Here's an example of how to determine the threshold regenerative torque: The formula for calculating regenerative torque is derived from the motor power formula: Motor power P = T × ω; where T is the regenerative torque and ω is the motor angular velocity. The regenerative torque is then derived from the motor power formula: T_regen_max = P_batt_max_charge / ω; where T_regen_max is the threshold regenerative torque; P_batt_max_charge is the threshold charging power; and ω is the motor angular velocity, calculated from the motor speed n (rpm): ω = 2 × π × n / 60.

[0050] The threshold compensation torque represents the maximum mechanical braking torque configured to prevent wheel lock-up in the current cornering scenario, i.e., the maximum braking torque allowed by mechanical braking in the current cornering scenario. Here's an example of how to determine the threshold compensation torque based on the ground adhesion coefficient: the threshold braking torque is determined based on the ground adhesion coefficient, the vehicle's mass, and the wheel radius; the difference between the threshold braking torque and the threshold recovery torque is determined as the threshold compensation torque.

[0051] For example, the threshold compensation torque is calculated according to the following formula: T_brake_comp_max = (μ×m×g×r)-T_motor_max; where T_brake_comp_max represents the threshold compensation torque; (u×m×g×r) represents the threshold braking torque, u represents the ground adhesion coefficient, m represents the mass of the vehicle, g represents the gravitational acceleration, r represents the wheel radius; and T_motor_max represents the threshold recovery torque.

[0052] The compensation torque is the portion of the expected recovery torque that exceeds the threshold recovery torque; that is, the difference between the expected recovery torque and the threshold recovery torque. The compensation torque represents the shortfall in the motor's braking capacity, which theoretically should be made up by the mechanical braking system. However, to avoid applying excessive braking force on low-traction surfaces (such as ice, snow, or slippery asphalt) that could cause wheel lock-up, the system also needs to assess road friction conditions in conjunction with the ground adhesion coefficient. This coefficient can be obtained through wheel speed difference estimation, IMU data fusion, or a dedicated road surface recognition algorithm, or it can be fed back in real time by the anti-lock braking system (ABS).

[0053] S130: Determine the target compensation torque based on the compensation torque and the threshold compensation torque, control the motor to output the first composite torque, and brake the wheels based on the target compensation torque; the first composite torque is the sum of the threshold recovery torque and the traction torque.

[0054] The target compensation torque is the torque parameter for mechanical braking of the wheels. The determination of the target compensation torque follows a safety-first principle: if the compensation torque does not exceed the threshold compensation torque, the entire shortfall can be covered by the mechanical system, and the target compensation torque is the compensation torque; conversely, only braking force within the upper limit is allowed to prevent slippage, and in this case, the target compensation torque equals the threshold compensation torque. This logic achieves dynamic limiting of the degree of mechanical braking intervention, ensuring stability under extreme conditions. Because the expected recovery torque value in S120 is greater than the threshold recovery torque value, it indicates that, considering the traction torque, the maximum recovery torque that the motor can provide (i.e., the first combined torque = threshold recovery torque + traction torque) still cannot meet all the torque required for vehicle braking, and mechanical braking of the wheels needs to be performed in conjunction, i.e., braking of the wheels based on the target compensation torque.

[0055] The target compensation torque can be quickly determined based on the relationship between the compensation torque and the threshold compensation torque. For example, if the value of the compensation torque is greater than the value of the threshold compensation torque, then the threshold compensation torque is determined as the target compensation torque; if the value of the compensation torque is less than or equal to the value of the threshold compensation torque, then the compensation torque is determined as the target compensation torque.

[0056] For example, if the compensation torque is -15 Nm and the threshold compensation torque is -10 Nm, then |-15 Nm| is obviously greater than |-10 Nm| (i.e., the value of the compensation torque is greater than the value of the threshold compensation torque). Therefore, -10 Nm (i.e., the threshold compensation torque) is determined as the target compensation torque.

[0057] For example, if the compensation torque is -10 Nm and the threshold compensation torque is -15 Nm, then obviously |-10 Nm| is less than |-15 Nm| (that is, the value of the compensation torque is less than the value of the threshold compensation torque), so -10 Nm (i.e. the compensation torque) is determined as the target compensation torque.

[0058] Here is an example of how to brake a wheel based on a target compensation torque: the frictional force between the brake pads and the brake disc is calculated based on the target compensation torque and the effective radius of the brake disc; the braking pressure of the brake wheel cylinder is calculated based on the frictional force and coefficient of friction between the brake discs, as well as the hydraulic area of ​​the brake wheel cylinder, so as to brake the wheel based on the braking pressure.

[0059] The target compensation braking torque is the difference between the braking torque required to be output by the motor, that is, the braking torque required for mechanical braking. Here, the target compensation braking torque is converted into the braking pressure of the corresponding brake wheel cylinder to perform fluid replenishment braking on the wheel, thereby achieving the synergistic purpose of motor braking and hydraulic mechanical braking to improve the vehicle braking effect.

[0060] The target compensation braking torque calculated above is the braking torque required for mechanical braking (T_Total_Brake_Tq): the torque generated by friction acting on the effective radius of the brake disc. T_Total_Brake_Tq = 2 × F_f × R_eff = 2 × μ × P × A × R_eff; where R_eff represents the effective radius of the brake disc (the average radius of the friction force); F_f represents the frictional force between the brake pads and the brake disc, F_f = μ × F_n = μ × P × A; F_n represents the normal force (i.e., the force applied to the brake pads by the brake fluid pressure), F_n = P × A; P represents the hydraulic pressure in the brake wheel cylinder (i.e., the braking pressure of the brake wheel cylinder); A represents the effective working area of ​​the brake wheel cylinder (caliper piston) (i.e., the hydraulic area of ​​the brake wheel cylinder); and μ represents the coefficient of friction.

[0061] The first combined torque is the final torque output by the motor when the desired recovered torque is greater than the threshold recovered torque. First combined torque = threshold recovered torque + traction torque. For example, if the desired recovered torque is -85 Nm, the threshold recovered torque is -70 Nm, and the traction torque is 15 Nm, then the first combined torque = -70 Nm + 15 Nm = -55 Nm. The first combined torque takes into account the traction torque required for vehicle cornering; that is, it considers the traction force required for cornering while applying motor braking, ensuring vehicle controllability in curves and preventing cornering failure due to insufficient power.

[0062] In some embodiments, if the desired recoverable torque is less than or equal to the threshold recoverable torque, it is not necessary to determine the target compensation torque or execute S130 as described above. The sum of the desired recoverable torque and the traction torque can be directly used as the second composite torque to control the motor to output the second composite torque. This situation indicates that the maximum recoverable torque that the motor can output can meet the current braking requirements of the vehicle. That is, it is only necessary to control the motor to output the second composite torque, without performing other braking operations, to achieve the expected vehicle braking effect.

[0063] For example, if the expected recovery torque is -70 Nm, the threshold recovery torque is -85 Nm, and the traction torque is 15 Nm, since |-70| is less than |-85| (i.e., the value of the expected recovery torque is less than the value of the threshold recovery torque), there is no need to apply mechanical braking to the wheels. It is only necessary to control the motor to output the second composite torque (i.e., the sum of the expected recovery torque and the traction torque, the second composite torque = -70 Nm + 15 Nm = -55 Nm). This takes into account the traction force required for the vehicle to turn while applying motor braking, so as to ensure the controllability of the vehicle in the curve and avoid the situation where the vehicle fails to turn due to insufficient power.

[0064] This application, when a vehicle is cornering, energy recovery is limited, and the vehicle's lateral acceleration exceeds a preset lateral acceleration, determines the initial recovery torque and the traction torque required for cornering by combining vehicle operating parameters, thus determining the desired recovery torque. If the desired recovery torque exceeds a threshold recovery torque, a target compensation torque required to brake the wheels is determined based on the compensation torque and the threshold compensation torque. The motor is controlled to output a first composite torque (the sum of the threshold recovery torque and the traction torque), causing the motor to output negative torque according to the first composite torque to produce a braking effect on the vehicle. Based on the target compensation torque, the wheels are braked (e.g., using a hydraulic braking system or electronic parking brake actuator to apply a mechanical braking force equivalent to the target compensation torque to the rear wheels on the inside of the turn) to reduce the cornering speed. This embodiment considers the traction torque required for vehicle cornering while coordinating motor braking and mechanical braking to ensure vehicle braking effectiveness while balancing the vehicle's safety and power requirements for cornering, enabling the vehicle to corner safely and smoothly.

[0065] In an exemplary embodiment, an instance scenario is provided to illustrate the control method described above: A vehicle enters a high-curvature curve at a speed of 60 km / h (lateral acceleration greater than 0.6g, where g is gravitational acceleration), and the driver releases the accelerator pedal (i.e., the vehicle is in a coasting energy recovery state). The battery temperature is -25°C, and the battery SOC is above 95%. At this time, the battery recovery power is limited, meaning the vehicle is in a high-curvature curve scenario with limited energy recovery. Based on the vehicle speed of 60 km / h and the lateral acceleration of 0.6g, the traction torque T_traction = +15 Nm is obtained from the traction torque MAP table. Based on the vehicle speed of 60 km / h and the accelerator pedal opening of 0%, the initial recovery torque T_req_target = -100 Nm is determined. The sum of these two values ​​is the desired recovery torque T_req_target_adj = -100 + 15 = -85 Nm. The initial recovery torque is reduced by introducing traction torque to obtain the desired recovery torque. The purpose is to prioritize the controllability of the vehicle in curves by leaving a margin for vehicle stability in advance, at the cost of sacrificing some braking efficiency.

[0066] If the current motor can actually reach the maximum recovery torque, i.e., the threshold recovery torque T_motor_max = -70 Nm, then the absolute value of T_req_target_adj (|-85|) is greater than the absolute value of T_motor_max (|-70|). Based on T_req_target_adj and T_motor_max, the compensation braking torque T_brake_comp = -85 - (-70) = -15 Nm is determined. Based on the ground adhesion coefficient μ... max Calculate the maximum permissible braking compensation torque, i.e., the threshold compensation torque T_brake_comp_max.

[0067] If |T_brake_comp|≤|T_brake_comp_max|, the final braking compensation torque, i.e., the target compensation torque, is T_brake_comp (i.e., -15 Nm); if |T_brake_comp|>|T_brake_comp_max|=|-10| Nm, the target compensation torque is T_brake_comp_max (i.e., -10 Nm).

[0068] The control motor outputs a first composite torque (i.e., the sum of the threshold recovery torque and the traction torque = -70Nm + 15Nm = -55Nm), and brakes the wheels based on the target compensation torque (i.e. -15Nm or -10Nm, which needs to be determined according to the relationship between the compensation torque and the threshold compensation torque).

[0069] In another exemplary embodiment of this application, the application scenarios of the above-mentioned multiple control methods are illustrated by way of example. Please refer to the following for details. Figure 2 , Figure 2 This is a schematic diagram illustrating an application scenario of the vehicle cornering control method of this application. It includes a vehicle 100 and a server 200, which can be connected wirelessly. This application does not limit the connection method between them.

[0070] Server 200 acts as the execution entity for any of the above control methods, and executes any of the above control methods, as illustrated below:

[0071] When vehicle 100 is in a cornering state, server 200, under the condition that vehicle 100 is in an energy recovery limited state and the lateral acceleration of vehicle 100 is greater than the preset lateral acceleration, determines the initial recovery torque and traction torque based on the operating parameters of vehicle 100, and thus determines the expected recovery torque. If the value of the expected recovery torque is greater than the value of the threshold recovery torque, server 200 determines the compensation torque based on the expected recovery torque and the threshold recovery torque, and determines the threshold compensation torque based on the ground adhesion coefficient. Server 200 determines the target compensation torque based on the compensation torque and the threshold compensation torque, and server 200 controls the motor to output the first composite torque, and brakes the wheels based on the target compensation torque. The first composite torque is the sum of the threshold recovery torque and the traction torque.

[0072] Server 200 can be as follows Figure 2 The server located in vehicle 100 shown can be a physical server outside of vehicle 100, or a server cluster or distributed system composed of multiple physical servers. Multiple servers can form a blockchain, and the server is a node on the blockchain. Server 200 can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. This document does not impose any restrictions on this.

[0073] Another aspect of this application provides a vehicle cornering control device, such as... Figure 3 As shown, Figure 3 This is a schematic diagram illustrating the structure of a vehicle cornering control device according to an exemplary embodiment of this application. The control device 300 includes:

[0074] The expected recovery torque determination module 310 is used to determine the expected recovery torque by determining the initial recovery torque and traction torque based on the vehicle's operating parameters when the vehicle is in a cornering state, under conditions where the vehicle's energy recovery is limited and the vehicle's lateral acceleration is greater than a preset lateral acceleration.

[0075] The compensation torque determination module 330 is used to determine the compensation torque based on the expected recovery torque and the threshold recovery torque if the value of the expected recovery torque is greater than the value of the threshold recovery torque, and to determine the threshold compensation torque based on the ground adhesion coefficient.

[0076] The control module 350 is used to determine the target compensation torque based on the compensation torque and the threshold compensation torque, control the motor to output the first composite torque, and brake the wheels based on the target compensation torque; the first composite torque is the sum of the threshold recovery torque and the traction torque.

[0077] In another exemplary embodiment, the compensation torque determination module 330 includes:

[0078] The threshold recovery torque determination unit is used to determine the threshold braking torque based on the ground adhesion coefficient, vehicle mass and wheel radius, and uses the quotient between the threshold charging power of the power battery and the angular velocity of the motor as the threshold recovery torque.

[0079] The compensation torque determination unit is used to determine the difference between the threshold braking torque and the threshold recovery torque as the threshold compensation torque.

[0080] In another exemplary embodiment, the control module 350 includes:

[0081] The friction force determination unit is used to calculate the friction force between the brake block and the brake disc based on the target compensation torque and the effective radius of the brake disc.

[0082] The control unit is used to calculate the braking pressure of the brake wheel cylinder based on the friction force and friction coefficient between the brake discs and the hydraulic area of ​​the brake wheel cylinder, so as to brake the wheel based on the braking pressure.

[0083] In another exemplary embodiment, the control device 300 further includes:

[0084] The energy recovery limited state determination module is used to determine that the vehicle is in an energy recovery limited state if the vehicle speed is greater than a preset vehicle speed, the accelerator pedal opening is less than a preset first opening, the brake pedal opening is less than a preset second opening, and the power battery temperature is less than a preset temperature and / or the remaining charge is greater than a preset remaining charge.

[0085] In another exemplary embodiment, the control module 350 includes:

[0086] The first target compensation torque determination unit is used to determine the threshold compensation torque as the target compensation torque if the value of the compensation torque is greater than the value of the threshold compensation torque.

[0087] The second target compensation torque determination unit is used to determine the compensation torque as the target compensation torque if the value of the compensation torque is less than or equal to the value of the threshold compensation torque.

[0088] In another exemplary embodiment, the operating parameters include the vehicle's driving mode, vehicle speed and accelerator pedal opening, power battery temperature and remaining charge; the compensation torque determination module 330 includes:

[0089] The initial recovery torque determination unit is used to determine the target MAP based on the driving mode, and to determine the initial recovery torque based on the vehicle speed, accelerator pedal opening and the target MAP.

[0090] The expected recovery torque determination unit is used to determine the traction torque based on the vehicle speed and lateral acceleration, and to use the sum of the initial recovery torque and the traction torque as the expected recovery torque.

[0091] In another exemplary embodiment, the control device 300 further includes:

[0092] The motor control module is used to take the sum of the expected recovered torque and the traction torque as the second composite torque if the value of the expected recovered torque is less than or equal to the value of the threshold recovered torque, and control the motor to output the second composite torque.

[0093] This application's control device, when the vehicle is cornering, under conditions of limited energy recovery, and with lateral acceleration exceeding a preset lateral acceleration, determines the initial recovery torque and the traction torque required for cornering by combining vehicle operating parameters. This determines the desired recovery torque. If the desired recovery torque exceeds a threshold recovery torque, the device determines the target compensation torque required to brake the wheels based on the compensation torque and the threshold compensation torque. The control motor outputs a first composite torque (the sum of the threshold recovery torque and the traction torque), causing the motor to output negative torque according to the first composite torque to produce a braking effect on the vehicle. Based on the target compensation torque, the device brakes the wheels (e.g., using a hydraulic braking system or electronic parking brake actuator to apply a mechanical braking force equivalent to the target compensation torque to the rear wheels on the inside of the turn) to reduce cornering speed. This application's control device, while considering the traction torque required for cornering, coordinates motor braking and mechanical braking to ensure effective braking while balancing the vehicle's safety and power requirements for cornering, enabling the vehicle to corner safely and smoothly.

[0094] It should be noted that the control device provided in the above embodiments and the control method provided in the foregoing embodiments belong to the same concept. The specific way in which each module and unit performs operations has been described in detail in the method embodiments, and will not be repeated here.

[0095] Another aspect of this application provides an electronic device, including: a controller; and a memory for storing one or more programs, which, when executed by the controller, perform the control method described above.

[0096] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a computer system for an electronic device according to an exemplary embodiment of this application, illustrating a schematic diagram of the structure of a computer system suitable for implementing the embodiments of this application.

[0097] It should be noted that, Figure 4 The computer system 400 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0098] like Figure 4 As shown, the computer system 400 includes a Central Processing Unit (CPU) 401, which can perform various appropriate actions and processes, such as executing the methods described in the above embodiments, based on a program stored in Read-Only Memory (ROM) 402 or a program loaded from storage portion 408 into Random Access Memory (RAM) 403. The RAM 403 also stores various programs and data required for system operation. The CPU 401, ROM 402, and RAM 403 are interconnected via a bus 404. An Input / Output (I / O) interface 405 is also connected to the bus 404.

[0099] The following components are connected to I / O interface 405: an input section 406 including a keyboard, mouse, etc.; an output section 407 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to I / O interface 405 as needed. A removable medium 411, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 410 as needed so that computer programs read from it can be installed into storage section 408 as needed.

[0100] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program including a computer program for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 409, and / or installed from removable medium 411. When the computer program is executed by central processing unit (CPU) 401, it performs various functions defined in the system of this application.

[0101] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable computer program. The transmitted data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0102] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0103] The units described in the embodiments of this application can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0104] Another aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the control method as described above. This computer-readable storage medium may be included in the electronic device described in the above embodiments, or it may exist independently and not assembled into the electronic device.

[0105] Another aspect of this application provides a computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the control methods provided in the various embodiments described above.

[0106] According to one aspect of the embodiments of this application, a computer system is also provided, including a Central Processing Unit (CPU), which can perform various appropriate actions and processes based on a program stored in read-only memory (ROM) or a program loaded from storage into random access memory (RAM), such as performing the methods described above. Various programs and data required for system operation are also stored in the RAM. The CPU, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0107] The following components are connected to the I / O interface: input components including keyboards, mice, etc.; output components including cathode ray tubes (CRTs), liquid crystal displays (LCDs), and speakers; storage components including hard drives; and communication components including network interface cards such as LAN (Local Area Network) cards and modems. The communication components perform communication processing via networks such as the Internet. Drives are also connected to the I / O interface as needed. Removable media, such as disks, optical discs, magneto-optical discs, semiconductor memories, etc., are installed on the drive as needed so that computer programs read from them can be installed into the storage components as required.

[0108] The above description is merely a preferred exemplary embodiment of this application and is not intended to limit the implementation of this application. Those skilled in the art can easily make corresponding modifications or alterations based on the main concept and spirit of this application. Therefore, the scope of protection of this application should be determined by the scope of protection claimed in the claims.

Claims

1. A control method of a vehicle turning around a curve, characterized by, The control method comprises: When the vehicle is in the over-bending state, if the vehicle is in the energy recovery limited state and the lateral acceleration of the vehicle is greater than a preset lateral acceleration, an initial recovery torque and a traction torque are determined according to the working condition parameters of the vehicle to determine a desired recovery torque; If the value of the desired recovery torque is greater than the value of the threshold recovery torque, a compensation torque is determined according to the desired recovery torque and the threshold recovery torque, and a threshold compensation torque is determined according to the ground adhesion coefficient; A target compensation torque is determined according to the compensation torque and the threshold compensation torque, a first combined torque is output by the motor, and the wheels are braked based on the target compensation torque; the first combined torque is the sum of the threshold recovery torque and the traction torque.

2. The control method according to claim 1, characterized by, The threshold compensation torque is determined according to the ground adhesion coefficient, which comprises: The threshold braking torque is determined according to the ground adhesion coefficient, the mass of the vehicle and the wheel radius, and the quotient between the threshold charging power of the power battery and the angular velocity of the motor is taken as the threshold recovery torque; The difference between the threshold braking torque and the threshold recovery torque is determined as the threshold compensation torque.

3. The control method according to claim 1, characterized by, The wheels are braked based on the target compensation torque, which comprises: The friction force between the brake block and the brake disc is calculated according to the target compensation torque and the effective radius of the brake disc; The brake pressure of the brake wheel cylinder is calculated according to the friction force between the brake disc and the friction coefficient, and the hydraulic area of the brake wheel cylinder, so that the wheels are braked based on the brake pressure.

4. The control method according to claim 1, characterized by, The control method further comprises: If the vehicle speed is greater than a preset vehicle speed, the accelerator pedal opening degree is less than a preset first opening degree, the brake pedal opening degree is less than a preset second opening degree, and the temperature of the power battery is less than a preset temperature and / or the remaining power is greater than a preset remaining power, it is determined that the vehicle is in the energy recovery limited state.

5. The control method according to claim 1, characterized by, The target compensation torque is determined according to the compensation torque and the threshold compensation torque, which comprises: If the value of the compensation torque is greater than the value of the threshold compensation torque, the threshold compensation torque is determined as the target compensation torque; If the value of the compensation torque is less than or equal to the value of the threshold compensation torque, the compensation torque is determined as the target compensation torque.

6. The control method according to any one of claims 1 to 5, characterized by, The working condition parameters comprise the driving mode of the vehicle, the vehicle speed and the accelerator pedal opening degree, the temperature of the power battery and the remaining power; The initial recovery torque and the traction torque are determined according to the working condition parameters of the vehicle to determine the desired recovery torque, which comprises: The target MAP diagram is determined according to the driving mode, and the initial recovery torque is determined according to the vehicle speed, the accelerator pedal opening degree and the target MAP diagram; The traction torque is determined according to the vehicle speed and the lateral acceleration, and the sum of the initial recovery torque and the traction torque is taken as the desired recovery torque.

7. The control method according to any one of claims 1 to 5, characterized by, The control method further comprises: If the value of the desired recovery torque is less than or equal to the value of the threshold recovery torque, the sum of the desired recovery torque and the traction torque is taken as a second combined torque, and the motor is controlled to output the second combined torque.

8. A control device for vehicle cornering, characterized in that, The control device comprises: The expected recovery torque determination module is configured to determine an initial recovery torque and a traction torque according to the working condition parameters of the vehicle when the vehicle is in the energy recovery limited state and the lateral acceleration of the vehicle is greater than a preset lateral acceleration, to determine an expected recovery torque when the vehicle is in the over-bending state. The compensation torque determination module is configured to determine a compensation torque according to the expected recovery torque and a threshold recovery torque, and determine a threshold compensation torque according to the ground adhesion coefficient, if the value of the expected recovery torque is greater than the value of the threshold recovery torque. The control module is configured to determine a target compensation torque according to the compensation torque and the threshold compensation torque, control the motor to output a first combined torque, and brake the wheel based on the target compensation torque; the first combined torque is the sum of the threshold recovery torque and the traction torque.

9. An electronic device, comprising: The control method comprises the following steps: controlling the motor to output a first combined torque, and braking the wheel based on the target compensation torque; the first combined torque is the sum of the threshold recovery torque and the traction torque. The controller; 10. A computer-readable storage medium, characterized in that, The memory is configured to store one or more programs, and the one or more programs, when executed by the controller, cause the controller to implement the control method in any one of claims 1 to 7. The computer readable instructions are stored on the computer readable medium, and when the computer readable instructions are executed by the processor of the computer, the computer executes the control method in any one of claims 1 to 7.

Images