Steering and braking cooperative control method and device, electronic equipment and storage medium

Abstract

The invention provides a steering and braking cooperative control method and device, electronic equipment and a storage medium, and relates to the technical field of vehicles. The steering and braking cooperative control method comprises the steps that according to state information of a steering execution system, the residual control capacity of the steering execution system when the capacity is limited is determined; determining a vehicle transverse control demand according to the vehicle driving path information and the vehicle actual motion state information; and distributing the vehicle transverse control demand between the steering execution system and a braking execution system according to the residual control capability of the steering execution system. According to the method, the path tracking capability and the driving stability of the vehicle can still be maintained when the steering system is partially invalid or the performance is reduced, a traditional fault-tolerant mode depending on single system redundancy is broken through, cooperative fault-tolerant control across execution systems is achieved, and the function safety level of the whole vehicle is improved on the premise that the hardware redundancy cost is not remarkably increased.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a steering and braking coordination control method, device, electronic device, and storage medium. Background Technology

[0002] With the development of automotive intelligence and autonomous driving technology, vehicle chassis systems are gradually evolving from mechanical connections to electronic and steer-by-wire systems. Steer-by-wire systems eliminate the mechanical connection between the steering wheel and the steering actuator, and use sensing, control and execution units to achieve steering functions. They have advantages such as flexible layout, adjustable steering characteristics, and easy integration with autonomous driving systems, and have become one of the important key technologies for high-level autonomous vehicles.

[0003] However, while steer-by-wire systems offer flexibility and intelligent potential, they also place higher demands on system reliability and functional safety. Since the steering link is highly dependent on the electronic and electrical system, problems such as sensor failure, motor performance degradation, controller malfunction, or communication interruption may directly affect the vehicle's lateral control capabilities, thereby posing safety risks. Summary of the Invention

[0004] The problem addressed by this invention is how to improve the safety and reliability of steer-by-wire systems under partial failure conditions.

[0005] To address the aforementioned problems, this invention provides a steering and braking coordinated control method, device, electronic device, and storage medium.

[0006] In a first aspect, the present invention provides a steering and braking coordinated control method, comprising: Determine the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system; The lateral control requirements of the vehicle are determined based on the vehicle's driving path information and the vehicle's actual motion status information. Based on the remaining control capability of the steering actuation system, the lateral control requirements of the vehicle are allocated between the steering actuation system and the braking actuation system.

[0007] Optionally, determining the remaining control capability of the steering system when it is under capacity constraints based on the state information of the steering system includes: The system is used to diagnose failures of the steering system based on sensor signals and actuator operating signals, and to determine the failure type when the steering system fails. The status information includes the sensor signals and actuator operating signals. The available control performance of the steering execution system is evaluated based on the failure type to determine the capability coefficient used to characterize the remaining control capability.

[0008] Optionally, the step of performing failure diagnosis on the steering system based on sensor signals and actuator operating signals to determine the failure type when the steering system fails includes: The angle sensor signal is compared with the estimated signal. When the deviation between the angle sensor signal and the estimated signal exceeds a first preset threshold, the failure type is determined to be a sensor failure. The estimated signal is determined based on the position signal of the steering motor and the transmission relationship. The sensor signal includes the angle sensor signal and the position signal. The commanded torque is compared with the actual output torque. When the following error between the commanded torque and the actual output torque exceeds a second preset threshold, the failure type is determined to be motor performance degradation. The actuator operating signal includes the actual output torque, and the commanded torque is determined by the steering controller.

[0009] Optionally, determining the vehicle's lateral control requirements based on the vehicle's driving path information and actual vehicle motion state information includes: The path tracking deviation is determined based on the vehicle's driving path information and its current position, wherein the actual vehicle motion state information includes the vehicle's current position. The vehicle lateral control requirements for reducing the path tracking deviation are determined based on the path tracking deviation.

[0010] Optionally, allocating the vehicle lateral control requirements between the steering and braking systems based on the remaining control capability of the steering system includes: The maximum lateral control amount that the steering system can provide is determined based on the remaining control capability of the steering system. The vehicle lateral control requirement is compared with the maximum lateral control amount, and the control amounts to be undertaken by the steering actuation system and the braking actuation system are determined based on the comparison results.

[0011] Optionally, determining the control quantities to be handled by the steering actuation system and the braking actuation system respectively based on the comparison results includes: When the vehicle lateral control requirement does not exceed the maximum lateral control amount, the steering actuation system shall independently undertake the vehicle lateral control requirement. When the vehicle's lateral control demand exceeds the maximum lateral control amount, the steering actuation system provides the control amount within its capacity, and the braking actuation system takes over the excess control amount.

[0012] Optionally, the control amount exceeding the limit undertaken by the braking actuation system includes: determining the target braking wheel and corresponding braking force based on the control amount required by the braking actuation system, determining the target wheel cylinder pressure based on the braking force, and controlling the braking actuation system to apply the corresponding target wheel cylinder pressure to achieve differential braking.

[0013] In a second aspect, the present invention provides a steering and braking coordination control device, comprising: The first module is used to determine the remaining control capability of the steering execution system when it is in a state of limited capability, based on the status information of the steering execution system. The second module is used to determine the vehicle's lateral control requirements based on the vehicle's driving path information and the vehicle's actual motion state information. The third module is used to allocate the vehicle's lateral control requirements between the steering and braking systems based on the remaining control capabilities of the steering system.

[0014] Thirdly, the present invention provides an electronic device, including a memory and a processor; The memory is used to store computer programs; The processor is configured to implement the steering and braking coordinated control method as described in the first aspect when executing the computer program.

[0015] Fourthly, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steering and braking coordinated control method as described in the first aspect.

[0016] The beneficial effects of the steering and braking coordinated control method of the present invention are as follows: when the steering actuator system is limited, the lateral control requirements of the vehicle are distributed between the steering actuator system and the braking actuator system. The braking actuator system compensates for the lateral control requirements that the steering actuator system cannot meet, so that the lateral control of the vehicle no longer depends solely on the steering system. Thus, even when the steering system experiences partial failure or performance degradation, the vehicle's path tracking ability and driving stability can still be maintained. This breaks through the traditional fault-tolerant mode that relies on the redundancy of a single system and realizes coordinated fault-tolerant control across actuator systems, thereby improving the functional safety level of the entire vehicle without significantly increasing the cost of hardware redundancy. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the steering and braking coordinated control method according to an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the principle of the steering and braking coordinated control method according to an embodiment of the present invention; Figure 3This is a schematic diagram of the process for determining the remaining control capability according to an embodiment of the present invention; Figure 4 This is a flowchart illustrating the process of determining the failure type according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the process for determining the lateral control requirements of a vehicle according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the process for allocating vehicle lateral control requirements according to an embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the specific process of allocating vehicle lateral control requirements according to an embodiment of the present invention; Figure 8 This is a system architecture diagram of the steering and braking coordinated control device according to an embodiment of the present invention; Figure 9 This is a system architecture diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0021] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0023] like Figure 1 As shown in the figure, an embodiment of the present invention provides a steering and braking coordinated control method, comprising: S100: Determine the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system.

[0024] Specifically, the steering system is first assessed based on its status information to determine if it is experiencing any limitations. If limitations are detected, its remaining control capabilities are then determined.

[0025] S200: Determines the vehicle's lateral control requirements based on the vehicle's driving path information and actual vehicle motion status information.

[0026] Specifically, the target driving path is obtained based on the navigation path or the autonomous driving planning path, and the vehicle's actual motion state information, such as the vehicle's current lateral position, heading angle, yaw rate, and vehicle speed, is combined to calculate the vehicle's lateral control requirements.

[0027] S300: Based on the remaining control capability of the steering actuator system, the lateral control requirements of the vehicle are allocated between the steering actuator system and the braking actuator system.

[0028] Specifically, based on the remaining control capability of the steering system, the vehicle's lateral control requirements are dynamically allocated between the steering and braking systems, thereby ensuring vehicle path tracking stability even when steering capability is limited.

[0029] Among them, combined Figure 2As shown, the control architecture of this embodiment generally includes a perception and input layer, a decision and control layer, a cooperative execution layer, and a vehicle dynamics system and state feedback loop. The perception and input layer is used to acquire the basic information required for control, including steering state information, target path information, and vehicle state information. Among them, the failure diagnosis and capability assessment module is used to identify whether the steering system has entered a capability-limited state, the path tracking and yaw moment demand calculation module is used to determine the control requirements based on the target path / driver intention and vehicle state, the cooperative control allocation core algorithm module is used to allocate control requirements between steering and braking, and the cooperative execution layer is used to execute the allocated control commands. Steering and braking work together on the vehicle dynamics system to change the vehicle's yaw motion and driving trajectory. The vehicle state is collected by sensors and fed back to the vehicle state estimator, and then input to the path tracking and yaw moment demand calculation module to form a closed-loop control.

[0030] In this embodiment, when the steering system's capabilities are limited, the vehicle's lateral control requirements are distributed between the steering and braking systems. This prevents the vehicle's lateral control from solely relying on the steering system. Consequently, even when the steering system experiences partial failure or performance degradation, the vehicle's path tracking capability and driving stability can still be maintained. This breaks through the traditional fault-tolerant mode that relies on the redundancy of a single system, achieving collaborative fault-tolerant control across execution systems and improving the overall vehicle's functional safety level without significantly increasing hardware redundancy costs.

[0031] Optionally, determining the remaining control capability of the steering system when it is under capacity constraints based on the state information of the steering system includes: S110: Perform failure diagnosis on the steering system based on the sensor signals and actuator operating signals of the steering system, and determine the failure type when the steering system fails. The status information includes the sensor signals and the actuator operating signals.

[0032] Specifically, in combination Figure 3 As shown, during the failure diagnosis phase, signals such as steering angle sensor signals (e.g., steering wheel angle signal measured by steering wheel angle sensor and / or wheel angle signal measured by front wheel angle sensor), motor position sensor signals (e.g., steering motor shaft position sensor signal), motor current signals (e.g., steering motor phase current signal), and controller communication status signals (e.g., communication status signal between steering controller and vehicle controller) can be collected. Based on the vehicle steering system dynamics model and signal consistency characteristics, the operating status of the steering system can be diagnosed in real time to identify the failure type. S120: Evaluate the available control performance of the steering execution system based on the failure type to determine the capability coefficient used to characterize the remaining control capability.

[0033] Specifically, in the capability assessment phase, the available control performance of the steering actuator is evaluated based on the failure type, such as decreased response bandwidth, limited maximum output torque, or reduced control accuracy. The capability coefficient α is then calculated based on the assessment results. steer This is used to quantify residual control capabilities.

[0034] In this optional embodiment, failure diagnosis is performed based on sensor signals and actuator operating signals, and the available control performance is evaluated in combination with the failure type. This can distinguish the degree of impact of different failure modes on steering capability, thereby achieving a quantitative characterization of the remaining control capability. This can provide a capability boundary basis for subsequent control allocation and improve the pertinence and rationality of fault-tolerant control.

[0035] Optionally, the step of performing failure diagnosis on the steering system based on sensor signals and actuator operating signals to determine the failure type when the steering system fails includes: S111: Compare the angle sensor signal with the estimated signal. When the deviation between the angle sensor signal and the estimated signal exceeds a first preset threshold, determine that the failure type is a sensor failure. The estimated signal is determined based on the position signal and transmission relationship of the steering motor. The sensor signal includes the angle sensor signal and the position signal.

[0036] Specifically, in combination Figure 4 As shown, for the steering angle sensor, the steering wheel angle sensor signal θ can be compared. s and via the steering motor position θ m The estimated rotation angle converted from the transmission ratio G (e.g., the estimated rotation angle is G*θ) m If the difference between the two is |θ s -G*θ m If ε1 exceeds time T1 and continues for a preset duration, the sensor is considered faulty, where ε1 is typically 1°. The steering system enters "open-loop assist mode," and the remaining steering capability is represented by the front wheel steering angle command δ. f No longer relying on faulty sensors, but still able to perform open-loop control through intact motors and their position sensors; at this point, the effective bandwidth and accuracy of the steering actuation system will decrease, but the basic steering function remains, and its capability coefficient α can be defined. steer =f(failure mode), for example α steer =0.7 indicates that its cornering response speed has dropped to 70% of normal.

[0037] S112: Compare the commanded torque with the actual output torque. When the following error between the commanded torque and the actual output torque exceeds a second preset threshold, determine that the failure type is motor performance degradation. The actuator operating signal includes the actual output torque, and the commanded torque is determined by the steering controller.

[0038] Specifically, for motor performance, monitor the command torque T cmd If the error in tracking the actual output torque exceeds a threshold ε2 (usually set to 5% of the motor's rated torque), the motor's torque output capability is deemed degraded, and the current maximum available torque ratio η (0 < η ≤ 1) is estimated. For example, the maximum available torque ratio η is determined based on the ratio between the commanded torque and the actual output torque. The maximum available torque ratio η represents the ratio of the maximum torque that the motor can actually stably output under the current fault condition to its rated maximum torque. When the motor performance degrades, the maximum output torque of the steering system is limited, and the front wheel steering angle δ... f With steering wheel angle θ s The steady-state relationship may remain unchanged, but the dynamic response will slow down, and it may saturate under large turning demands (such as emergency obstacle avoidance).

[0039] Among them, the actual output torque T est It can be represented as T est =K t *I m K t The torque constant of a motor (Nm / A) is a constant determined by the motor's own physical parameters. m This indicates the motor current.

[0040] Among them, the ability coefficient α steer The relationship between the motor performance degradation factor η and the system dynamic characteristics depends on the system dynamics. Typically, η represents the degradation percentage of the motor's maximum output torque (e.g., η = 0.8 means the maximum torque is reduced to 80% of normal). steer This characterizes the degradation ratio of the dynamic response speed of the steering system (e.g., a in the sensor failure example). steer = 0.7 indicates that the response speed has dropped to 70%); for motor performance degradation, a reasonable model is to assume that the bandwidth or response speed of the steering system is proportional to the maximum torque, that is: a steer =η, which means the dynamic response speed is reduced to η times the normal value; this relationship is based on simplified analysis: within the small-signal linear range, the system open-loop gain is proportional to the motor torque constant, while the bandwidth is approximately proportional to the open-loop gain, hence α steer ∝η; If nonlinearity or saturation effects are considered (such as during large-scale shifts in demand), the relationship may be more complex, for example: α steer=η^k (0.5≤k≤1), where k reflects the system's sensitivity to torque limitations; the actual functional form needs to be determined based on specific system parameters and controller design, but the basic trend is α steer It increases with increasing η, and when η=1, α steer When α = 1 and η = 0, α steer =0.

[0041] In this optional embodiment, by comparing the angle sensor signal with the estimated signal obtained based on the motor position and transmission relationship, the sensor anomaly can be effectively identified. By comparing the command torque with the actual output torque, the motor performance degradation can be detected. Cross-validation using the inherent physical correlation improves the reliability and accuracy of fault diagnosis, reduces false positives and false negatives, and is conducive to the stable triggering of the fault-tolerant control strategy.

[0042] Optionally, determining the vehicle's lateral control requirements based on the vehicle's driving path information and actual vehicle motion state information includes: S210: Determine the path tracking deviation based on the vehicle's driving path information and its current position, wherein the vehicle's actual motion state information includes the vehicle's current position.

[0043] Specifically, in combination Figure 5 As shown, obtain the target path information (expected horizontal position Y). des Desired heading angle ψ des Actual vehicle status (actual lateral position Y, actual heading angle ψ, yaw rate y, vehicle speed V) x The lateral deviation is calculated as e. y =Y des -Y, heading deviation is e ψ =ψ des -ψ.

[0044] S220: Determine the vehicle lateral control requirements for reducing the path tracking deviation based on the path tracking deviation.

[0045] Specifically, the controller is designed using a pre-aiming tracking model or a linear quadratic regulator (LQR), and the total additional yaw moment ΔM required to eliminate the deviation is calculated. z_des Taking single-point pre-aiming as an example, the pre-aiming distance is L. p =τ*V x (τ is the aiming time), and the lateral deviation of the aiming point is e. y_pre =e y +L p *sin(e ψ The required yaw moment is ΔM. z_des =K p *e y_pre +K d*(d(e y_pre ) / dt)+K ψ *e ψ ; Among them, K p K d K ψ The controller gain can be obtained by tuning the parameters of the vehicle model (such as a two-degree-of-freedom vehicle model).

[0046] In this optional embodiment, by determining the vehicle's lateral control requirements based on path tracking deviation, the control target is directly oriented towards the path tracking error rather than the control quantity of a single actuator. This allows for a more accurate reflection of the vehicle's overall motion requirements, which is beneficial for achieving a unified control target in multi-actuator collaborative control scenarios and improving vehicle path tracking accuracy and control consistency.

[0047] Optionally, allocating the vehicle lateral control requirements between the steering and braking systems based on the remaining control capability of the steering system includes: S310: Determine the maximum lateral control amount that the steering actuator can provide based on the remaining control capability of the steering actuator.

[0048] Specifically, in combination Figure 6 As shown, based on the ability coefficient α steer Given the current vehicle speed and the vehicle dynamics model, the maximum yaw control that the steering system can provide is calculated.

[0049] S320: Compare the vehicle lateral control requirement with the maximum lateral control amount, and determine the control amounts to be undertaken by the steering actuation system and the braking actuation system respectively based on the comparison result.

[0050] Specifically, the yaw moment requirement corresponding to the vehicle's lateral control needs is compared with the maximum yaw control quantity (used to characterize the maximum yaw moment capability), and the control quantities to be undertaken by the steering actuation system and the braking actuation system are determined based on the comparison results.

[0051] In this optional embodiment, by determining the maximum lateral control amount based on the remaining control capability and comparing it with the vehicle's lateral control requirements, the control allocation is based on the actual capability of the actuator, avoiding the issuance of control commands beyond the capability range, thereby reducing the risk of actuator saturation and control instability, and improving system stability and safety margin.

[0052] Optionally, determining the control quantities to be handled by the steering actuation system and the braking actuation system respectively based on the comparison results includes: S321: When the vehicle lateral control requirement does not exceed the maximum lateral control amount, the steering execution system shall independently undertake the vehicle lateral control requirement.

[0053] Specifically, in combination Figure 7 As shown, when the vehicle's lateral control demand does not exceed the maximum lateral control amount, the steering execution system independently undertakes the vehicle's lateral control demand.

[0054] S322: When the vehicle's lateral control demand exceeds the maximum lateral control amount, the steering actuation system provides the control amount within its capacity, and the braking actuation system undertakes the control amount exceeding the limit.

[0055] Specifically, when the vehicle's lateral control demand exceeds the maximum lateral control amount, the steering system outputs its maximum available capacity, and the remaining demand is handled by the braking system. Steering control can be used preferentially to reduce the impact of braking intervention on comfort.

[0056] The objective of the steering-braking coordinated control allocation is to reduce the total yaw moment demand ΔM. z_des Dynamically allocated to the steering system (generating ΔM) z_steer ) and differential braking system (generating ΔM z_brake An exemplary allocation process is as follows: (1) Based on the two-degree-of-freedom vehicle model, the calculation of the front wheel steering angle δ by simply adjusting the front wheel steering angle is performed. f The incremental yaw moment (the incremental yaw moment characterizes the steering system's ability to adjust to the vehicle's lateral motion and can be used as a quantitative indicator of the steering system's lateral control capability); Vehicle lateral stiffness: Front axle C f Rear axle C r Wheelbase: L (a is the distance from the center of mass to the front axle, b = La, the distance from the center of mass to the rear axle), Stability factor: K = m / (L^2)*(a / C) r -b / C f ), where m represents the vehicle mass. Under steady state, the front wheel steering angle increment Δδ f The estimated increase in the yaw moment is as follows: ΔM z_steer_max =(V x ^2 / (1+K*V x ^2))*(C f *Δδ f )*a (Simplified formula, ignoring dynamic processes); Considering the remaining steering capacity α steer and the current front wheel steering angle δ f Is it close to saturation? Calculate the maximum yaw moment ΔM that the steering system can safely and quickly provide at the current moment. z_steer_avail ; where ΔMz_steer_max It can represent the maximum yaw moment that can theoretically be generated by a change in rotation angle, ΔM z_steer_avail This indicates the actual yaw moment that can be safely provided under the current operating conditions.

[0057] (2) If |ΔM z_des | ≤|ΔM z_steer_avail |, then the steering system will handle the entire task: ΔM z_steer =ΔM z_des ; ΔM z_brake =0; New front wheel steering angle command δ f_cmd ΔM is obtained through reverse vehicle modeling or table lookup. z_steer We can deduce this by working backwards; If |ΔM z_des |>|ΔM z_steer_avail | Then, braking coordination will be activated: ΔM z_steer =sign(ΔM z_des )*|ΔMz _steer_avail The steering system contributes its maximum capability, where sign represents the sign function, i.e., ΔM. z_des When greater than zero, sign(ΔM) z_des ) is 1, ΔM z_des When it equals zero, sign(ΔM) z_des ) is 0, ΔM z_des When less than zero, sign(ΔM) z_des A value of -1 ensures that the direction of the yaw moment output by the steering system is consistent with the direction of the target yaw moment; for example, ΔM z_des = +1000 Nm, ΔM z_steer_avail = 600 Nm, then ΔM z_steer = +600Nm, ΔM z_brake = 400 Nm; ΔM z_brake =ΔM z_des -ΔM z_steer The remaining portion is borne by the braking system; In this optional embodiment, the steering system is given priority to take over the control task when the demand is within limits, and the braking system is used to supplement it when the demand exceeds limits. This allows the control strategy to take into account both response continuity and comfort, reduce unnecessary braking intervention, reduce the impact on longitudinal dynamics and ride comfort, and at the same time ensure that there is still sufficient lateral control capability under extreme demand.

[0058] Optionally, the control amount exceeding the limit undertaken by the braking actuation system includes: determining the target braking wheel and corresponding braking force based on the control amount required by the braking actuation system, determining the target wheel cylinder pressure based on the braking force, and controlling the braking actuation system to apply the corresponding target wheel cylinder pressure to achieve differential braking.

[0059] Specifically, the target braking wheel and corresponding braking force are determined based on the control quantities required by the braking execution system. For example, when a positive yaw moment (a positive yaw moment is a torque that causes the vehicle to turn to the left) is required, the left rear wheel is braked; when a negative yaw moment is required, the right rear wheel is braked. The required braking force is calculated based on the target yaw moment and the vehicle's wheelbase, and then converted into target wheel cylinder pressure based on the brake efficiency factor. The ESC hydraulic control unit precisely adjusts the pressure based on the target wheel cylinder pressure to achieve differential braking control.

[0060] An example of differential braking is as follows: Assuming a braking force F is applied to the left rear wheel xb_lr The resulting yaw moment is: ΔM z_brake =F xb_lr ×(t w / 2); Where t w This refers to the rear wheel track.

[0061] Therefore, the required braking force is: F xb_lr =(2*ΔM z_brake ) / t w (If ΔM) z_brake If positive, the left rear wheel needs to be braked to turn the vehicle to the right; if negative, the right rear wheel needs to be braked.

[0062] Finally, the ESC hydraulic control unit receives the target wheel cylinder pressure command P. cmd =F xb_lr / k b (k) b (This is the brake efficiency factor), and it is executed precisely.

[0063] According to vehicle dynamics, single-sided rear-wheel braking is the most effective way to generate yaw moment with relatively little impact on longitudinal dynamics. In other embodiments, combined front and rear wheel braking or multi-wheel coordinated braking is feasible. This involves treating the vehicle chassis as a torque distribution platform and using an electronic control system to collaboratively calculate and independently control the braking forces of multiple wheels, thereby vector-synthesizing the target yaw moment. For example, simultaneously braking the left front wheel and right rear wheel (diagonal braking) can utilize a longer lever arm to generate a stronger rotational effect; while braking two wheels on the same side can quickly provide a large corrective torque. More advanced multi-wheel coordinated strategies (such as torque vector control) can use optimized algorithms to accurately generate the required yaw moment while coordinating the torque of other wheels to counteract unnecessary longitudinal deceleration, thereby improving handling response while minimizing the impact on longitudinal dynamics.

[0064] In this optional embodiment, the target braking wheel and braking force are determined based on the required control quantity and further converted into wheel cylinder pressure for precise control, enabling differential braking to participate in lateral control in a controllable manner, making full use of the existing braking system's execution capabilities, and generating additional yaw torque without additional hardware.

[0065] like Figure 8 As shown, an embodiment of the present invention provides a steering and braking coordination control device 800, comprising: The first module 810 is used to determine the remaining control capability of the steering execution system when it is in a state of limited capability based on the status information of the steering execution system. The second module 820 is used to determine the vehicle's lateral control requirements based on the vehicle's driving path information and the vehicle's actual motion state information. The third module 830 is used to allocate the vehicle's lateral control requirements between the steering system and the braking system based on the remaining control capability of the steering system.

[0066] like Figure 9 As shown, an electronic device 900 provided in this embodiment of the invention includes a memory 920 and a processor 910; the memory 920 is used to store a computer program; the processor 910 is used to implement the steering and braking coordinated control method as described above when the computer program is executed.

[0067] Alternatively, an electronic device 900 includes a memory 920 and a processor 910 coupled to the memory 920; the memory 920 is configured to store a computer program; and the processor 910 is configured to perform the following operations when the computer program is executed: Determine the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system; The lateral control requirements of the vehicle are determined based on the vehicle's driving path information and the vehicle's actual motion status information. Based on the remaining control capability of the steering actuation system, the lateral control requirements of the vehicle are allocated between the steering actuation system and the braking actuation system.

[0068] This invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the steering and braking coordinated control method as described above.

[0069] Alternatively, a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the following operations: Determine the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system; The lateral control requirements of the vehicle are determined based on the vehicle's driving path information and the vehicle's actual motion status information. Based on the remaining control capability of the steering actuation system, the lateral control requirements of the vehicle are allocated between the steering actuation system and the braking actuation system.

[0070] The present invention will now be described an electronic device 900 that can serve as a server or client of the present invention, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic device 900 is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 900 can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0071] Electronic device 900 includes a computing unit that can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) or a computer program loaded from a storage unit into random access memory (RAM). The RAM may also store various programs and data required for device operation. The computing unit, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus.

[0072] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. In this application, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs. Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units can be implemented in hardware or as software functional units.

[0073] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A steering and braking coordinated control method, characterized in that, include: Determine the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system; The lateral control requirements of the vehicle are determined based on the vehicle's driving path information and the vehicle's actual motion status information. Based on the remaining control capability of the steering actuation system, the lateral control requirements of the vehicle are allocated between the steering actuation system and the braking actuation system.

2. The steering and braking coordinated control method according to claim 1, characterized in that, Determining the remaining control capability of the steering execution system when it is under limited capability based on the status information of the steering execution system includes: The system is used to diagnose failures of the steering system based on sensor signals and actuator operating signals, and to determine the failure type when the steering system fails. The status information includes the sensor signals and actuator operating signals. The available control performance of the steering execution system is evaluated based on the failure type to determine the capability coefficient used to characterize the remaining control capability.

3. The steering and braking coordinated control method according to claim 2, characterized in that, The step of performing failure diagnosis on the steering system based on sensor signals and actuator operating signals to determine the failure type when the steering system fails includes: The angle sensor signal is compared with the estimated signal. When the deviation between the angle sensor signal and the estimated signal exceeds a first preset threshold and continues for a preset duration, the failure type is determined to be a sensor failure. The estimated signal is determined based on the position signal of the steering motor and the transmission relationship. The sensor signal includes the angle sensor signal and the position signal. The commanded torque is compared with the actual output torque. When the following error between the commanded torque and the actual output torque exceeds a second preset threshold, the failure type is determined to be motor performance degradation. The actuator operating signal includes the actual output torque, and the commanded torque is determined by the steering controller.

4. The steering and braking coordinated control method according to claim 1, characterized in that, Determining the vehicle's lateral control requirements based on vehicle travel path information and actual vehicle motion state information includes: The path tracking deviation is determined based on the vehicle's driving path information and its current position, wherein the actual vehicle motion state information includes the vehicle's current position. The vehicle lateral control requirements for reducing the path tracking deviation are determined based on the path tracking deviation.

5. The steering and braking coordinated control method according to claim 1, characterized in that, The step of allocating the vehicle lateral control requirements between the steering and braking systems based on the remaining control capability of the steering system includes: The maximum lateral control amount that the steering system can provide is determined based on the remaining control capability of the steering system. The vehicle lateral control requirement is compared with the maximum lateral control amount, and the control amounts to be undertaken by the steering actuation system and the braking actuation system are determined based on the comparison results.

6. The steering and braking coordinated control method according to claim 5, characterized in that, The determination of the control quantities to be undertaken by the steering actuation system and the braking actuation system respectively based on the comparison results includes: When the vehicle lateral control requirement does not exceed the maximum lateral control amount, the steering actuation system shall independently undertake the vehicle lateral control requirement. When the vehicle's lateral control demand exceeds the maximum lateral control amount, the steering actuation system provides the control amount within its capacity, and the braking actuation system takes over the excess control amount.

7. The steering and braking coordinated control method according to claim 6, characterized in that, The control quantity exceeding the limit undertaken by the braking execution system includes: determining the target braking wheel and corresponding braking force based on the control quantity required by the braking execution system, determining the target wheel cylinder pressure based on the braking force, and controlling the braking execution system to apply the corresponding target wheel cylinder pressure to achieve differential braking.

8. A steering and braking coordinated control device, characterized in that, include: The first module is used to determine the remaining control capability of the steering execution system when it is in a state of limited capability, based on the status information of the steering execution system. The second module is used to determine the vehicle's lateral control requirements based on the vehicle's driving path information and the vehicle's actual motion state information. The third module is used to allocate the vehicle's lateral control requirements between the steering and braking systems based on the remaining control capabilities of the steering system.

9. An electronic device, characterized in that, Including memory and processor; The memory is used to store computer programs; The processor is configured to implement the steering and braking coordinated control method as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steering and braking coordinated control method as described in any one of claims 1 to 7.

Images