A brake control method, device, vehicle and readable storage medium

Abstract

The present application relates to the technical field of vehicle braking, and discloses a brake control method, device, vehicle and readable storage medium, in response to motor assistance failure, the present application acquires brake pedal depth signals and hydraulic line brake-by-wire system assistance motor position signals, and based on the state of the two types of signals, determines the strategy of brake control through pure mechanical master cylinder hydraulic torque and motor feedback torque, or brake control through the combination of pure mechanical master cylinder hydraulic torque, motor feedback torque and hydraulic line brake-by-wire system compensation hydraulic brake torque, then determines the torque value of the motor feedback torque, or the torque value of the motor feedback torque and the hydraulic line brake-by-wire system compensation hydraulic brake torque respectively, realizes the selection of at least one of the motor feedback torque and the compensation hydraulic brake torque for auxiliary braking based on the current signal state, and solves the problems of poor pedal feel and reduced deceleration after the full decoupling hydraulic line brake-by-wire system motor assistance failure.

Description

Technical Field

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

[0002] With the rapid development of new energy vehicles, especially the fast acceleration performance of pure electric vehicles, the vehicles must have a reliable braking system to ensure the safety of the driver. At the same time, in order to improve the driving range of new energy vehicles and achieve better energy recovery of the motor, the industry mainstream uses a fully decoupled hydraulic brake-by-wire system for the braking system's power assist system. However, when the motor assist of the fully decoupled hydraulic brake-by-wire system fails, the braking force of the brake caliper relies entirely on mechanical hydraulics, which will result in a worse pedal feel and reduced deceleration. Summary of the Invention

[0003] This invention provides a braking control method, device, vehicle, and readable storage medium to solve the problem that when the motor assist of a fully decoupled hydraulic brake-by-wire system fails, the braking force of the brake caliper relies entirely on mechanical hydraulics, which leads to a decrease in pedal feel and a reduction in deceleration.

[0004] In a first aspect, the present invention provides a braking control method using a controller in a vehicle, the vehicle being equipped with a hydraulic brake-by-wire system and a drive motor. The method includes: in response to a failure of the motor assist in the fully decoupled hydraulic brake-by-wire system, acquiring a brake pedal depth signal and a position signal of the hydraulic brake-by-wire system assist motor, and determining the states of the brake pedal depth signal and the assist motor position signal; based on the states of the brake pedal depth signal and the assist motor position signal, determining a braking torque control strategy, wherein the braking torque control strategy is braking control through a combination of pure mechanical master cylinder hydraulic torque and motor feedback torque, or braking control through a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque, and hydraulic brake-by-wire system compensating hydraulic braking torque; based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque, determining the torque value of the motor feedback torque of the braking torque control strategy, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensating hydraulic braking torque, respectively, and performing braking control based on the braking torque control strategy.

[0005] The braking control method provided by this invention, in response to the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, acquires the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's assist motor, determines the state of these two signals, and then determines a braking torque control strategy based on the state of these two signals. The braking torque control strategy can be achieved through braking control using the hydraulic torque of the pure mechanical master cylinder and the motor feedback torque, or through a combination of the hydraulic torque of the pure mechanical master cylinder, the motor feedback torque, and the hydraulic brake-by-wire system's compensating hydraulic braking torque. Based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque, the torque value of the motor feedback torque of the braking torque control strategy is determined; alternatively, the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system's compensating hydraulic braking torque are determined separately, and braking control is performed based on the braking torque control strategy. This achieves the selection of at least one of the motor feedback torque and the compensating hydraulic braking torque for auxiliary braking based on the current signal state, solving the problems of deteriorated pedal feel and reduced deceleration after the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, thus improving vehicle safety.

[0006] In one optional implementation, determining the braking torque control strategy based on the state of the brake pedal depth signal and the state of the power assist motor position signal includes: if the brake pedal depth signal is in a normal state but the power assist motor position signal is in a failed state, determining the braking torque control strategy as braking control through pure mechanical master cylinder hydraulic torque and motor feedback torque; if both the brake pedal depth signal and the power assist motor position signal are in a normal state, determining the braking torque control strategy as braking control through a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque control, and hydraulic brake-by-wire system compensation hydraulic braking torque.

[0007] When both signals are normal, this invention activates the motor compensation pressure building function, which improves the vehicle deceleration through three-level torque coordination. When the power assist motor position signal fails, it uses a combination of motor feedback torque and pure mechanical master cylinder hydraulic torque for braking control to compensate for the lack of mechanical torque.

[0008] In one optional implementation, the method further includes: if the brake pedal depth signal is in a failed state, controlling the braking of the vehicle's four-wheel calipers by using the hydraulic torque of the purely mechanical master cylinder.

[0009] This invention enables braking control of the vehicle's four-wheel calipers through the hydraulic torque of the purely mechanical master cylinder when the brake pedal depth signal is in a failed state. This provides a backup braking function in the event of a failure, eliminates the risk of complete brake failure, and ensures vehicle braking stability.

[0010] In one optional implementation, if the brake pedal depth signal is in a normal state but the power assist motor position signal is in a failed state, the torque value of the motor feedback torque of the braking torque control strategy is determined based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque. This includes: obtaining the current brake pedal travel; determining the available pure mechanical master cylinder hydraulic torque based on a preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel; calculating the difference between the vehicle's braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain a first compensating braking torque; determining the available motor feedback torque based on a preset mapping relationship between the brake pedal travel and the available motor feedback torque; and determining the minimum torque value between the first compensating braking torque and the available motor feedback torque as the torque value of the motor feedback torque.

[0011] This invention uses mechanical hydraulic torque as the basic braking force to provide the core braking force, and motor feedback torque as the compensating braking force. This ensures the braking performance of the whole vehicle, and reduces energy loss during braking within the range of the motor's usability, thus balancing braking performance and energy saving.

[0012] In an optional implementation, before determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, the method further includes: determining whether the current brake pedal travel is in the idle travel stage; if the current brake pedal travel is in the idle travel stage; determining the vehicle braking demand torque or the available motor feedback torque as the torque value of the motor feedback torque; if the current brake pedal travel has completed the idle travel stage, performing the step of determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel.

[0013] This invention sets up motor feedback torque braking during the idle stroke stage to eliminate braking lag caused by the idle stroke and improve braking safety. After the idle stroke is completed, the coordinated compensation of hydraulic torque of mechanical master cylinder and motor feedback torque is activated to achieve torque control that perfectly matches the actual working state of the braking system.

[0014] In one optional implementation, if both the brake pedal depth signal and the power assist motor position signal are in a normal state, the values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensation hydraulic braking torque of the braking torque control strategy are determined based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque. This includes: obtaining the current brake pedal travel; determining the available pure mechanical master cylinder hydraulic torque based on a preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel; calculating the difference between the vehicle's braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain a second compensation braking torque; obtaining the available motor feedback torque based on a preset mapping relationship between the brake pedal travel and the available motor feedback torque; and if the second compensation braking torque is not greater than the available motor feedback torque, determining the second compensation braking torque as the motor feedback torque value, and setting the hydraulic brake-by-wire system compensation hydraulic braking torque value to zero.

[0015] This invention is designed to allow the motor's regenerative torque to prioritize compensating for braking needs beyond the mechanical hydraulic torque, thereby maximizing the energy-saving advantages of motor regenerative braking and reducing the workload of the hydraulic drive-by-wire system.

[0016] In an optional embodiment, the method further includes: if the second compensating braking torque is greater than the available motor feedback torque, determining the available motor feedback torque as the torque value of the motor feedback torque; calculating the difference between the second compensating braking torque and the available motor feedback torque to obtain a first hydraulic compensating torque; and determining the first hydraulic compensating torque as the torque value of the hydraulic brake-by-wire system compensating for the hydraulic braking torque.

[0017] This invention ensures that the braking requirements of the entire vehicle are fully covered by quantitatively calculating the difference and accurately supplementing it by the hydraulic drive-by-wire system after the motor feedback torque reaches the upper limit of usability.

[0018] In an optional implementation, the method further includes: if the current brake pedal travel is in the idle travel phase; determining the magnitude of the vehicle braking demand torque and the available motor feedback torque; if the vehicle braking demand torque is not greater than the available motor feedback torque, determining the vehicle braking demand torque as the torque value of the motor feedback torque.

[0019] This invention directly responds to braking demand through motor feedback torque during the idle stroke phase, which not only fills the braking force gap during the idle stroke but also avoids excessive motor feedback, thus achieving synchronous connection between braking intention and braking execution.

[0020] In an optional embodiment, the method further includes: if the vehicle braking demand torque is greater than the available motor feedback torque, determining the available motor feedback torque as the torque value of the motor feedback torque; calculating the difference between the vehicle braking demand torque and the available motor feedback torque to obtain a second hydraulic compensation torque; and determining the second hydraulic compensation torque as the torque value of the hydraulic brake-by-wire system to compensate for the hydraulic braking torque.

[0021] This invention covers high braking demand scenarios and provides full braking force supply by using full feedback from the motor and hydraulic compensation.

[0022] Secondly, the present invention provides a braking control device, which applies a controller in a vehicle. The vehicle is equipped with a hydraulic brake-by-wire system and a drive motor. The device includes: a signal acquisition module, used to acquire a brake pedal depth signal and a hydraulic brake-by-wire system assist motor position signal in response to a failure of the fully decoupled hydraulic brake-by-wire system motor assist, and to determine the state of the brake pedal depth signal and the assist motor position signal; a braking control strategy determination module, used to determine a braking torque control strategy based on the state of the brake pedal depth signal and the state of the assist motor position signal, wherein the braking torque control strategy is braking control through a combination of pure mechanical master cylinder hydraulic torque and motor feedback torque, or braking control through a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque, and hydraulic brake-by-wire system compensating hydraulic braking torque; and a torque value calculation module, used to determine the torque value of the motor feedback torque of the braking torque control strategy, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensating hydraulic braking torque, respectively, based on the vehicle braking demand torque and the pure mechanical master cylinder hydraulic torque, and to perform braking control based on the braking torque control strategy.

[0023] Thirdly, the present invention provides a vehicle equipped with a hydraulic brake-by-wire system, a drive motor, and a controller. The controller includes a memory and a processor, which are communicatively connected. The memory stores computer instructions, and the processor executes the computer instructions to perform the braking control method of the first aspect or any corresponding embodiment described above.

[0024] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the braking control method of the first aspect or any corresponding embodiment thereof.

[0025] The present invention has the following technical effects: The braking control method provided by this invention, in response to the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, acquires the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's assist motor, determines the state of these two signals, and then determines a braking torque control strategy based on the state of these two signals. The braking torque control strategy can be achieved through braking control using the hydraulic torque of the pure mechanical master cylinder and the motor feedback torque, or through a combination of the hydraulic torque of the pure mechanical master cylinder, the motor feedback torque, and the hydraulic brake-by-wire system's compensating hydraulic braking torque. Based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque, the torque value of the motor feedback torque of the braking torque control strategy is determined; alternatively, the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system's compensating hydraulic braking torque are determined separately, and braking control is performed based on the braking torque control strategy. This achieves the selection of at least one of the motor feedback torque and the compensating hydraulic braking torque for auxiliary braking based on the current signal state, solving the problems of deteriorated pedal feel and reduced deceleration after the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, thus improving vehicle safety. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of a first embodiment of the braking control method according to the present invention; Figure 2 This is a schematic diagram of a second type of braking control method according to an embodiment of the present invention; Figure 3 This is an example diagram of the judgment process of the braking torque control strategy according to an embodiment of the present invention; Figure 4 This is an example diagram showing the mapping curves between the brake pedal travel and the available motor feedback torque, the purely mechanical master cylinder hydraulic torque, and the vehicle braking demand torque according to an embodiment of the present invention. Figure 5 This is a flowchart illustrating the auxiliary control process for compensating hydraulic braking torque in a hydraulic brake-by-wire system according to an embodiment of the present invention. Figure 6 This is a structural block diagram of a vehicle according to an embodiment of the present invention; Figure 7 This is a structural block diagram of a braking control device according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the hardware structure of the controller according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] According to an embodiment of the present invention, a braking control method embodiment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] This embodiment provides a braking control method that can be used in a vehicle controller, wherein the vehicle is equipped with a hydraulic brake-by-wire system and a drive motor. Figure 1 This is a flowchart of a braking control method according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S101: In response to the failure of the motor assist in the fully decoupled hydraulic brake-by-wire system, acquire the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system assist motor, and determine the status of the brake pedal depth signal and the assist motor position signal.

[0032] This invention can monitor the working status of the assist motor of a fully decoupled hydraulic brake-by-wire system in real time, for example, by monitoring the motor current, drive command response value, etc. If no drive current is output from the motor within a continuous time period, or the actual speed of the motor deviates significantly from the commanded speed, or a motor fault code is triggered, it can be determined that the motor assist of the fully decoupled hydraulic brake-by-wire system has failed (the electronic control unit (ECU) is functioning normally). The ECU function includes, but is not limited to, normal ECU operation, normal communication, and normal ECU signal interaction, etc., which are only examples and are not limited.

[0033] In this embodiment of the invention, upon detecting a failure of the motor assist in the fully decoupled hydraulic brake-by-wire system, the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system assist motor can be obtained through the ECU of the hydraulic brake-by-wire system. The system then determines whether the brake pedal signal and the assist motor position signal are communicating normally. The method for determining whether the two signals are communicating normally is not limited; it can be done directly through the CAN bus communication status flag to monitor whether the transmission link of the two types of signals is normal. Alternatively, it can be determined whether the brake pedal depth signal communication is normal through data such as the pedal depth value and the rate of change of pedal depth. The assist motor position signal can be determined by whether the motor rotor position is within the effective range and whether the position signal changes continuously with pedal movement. These are merely examples.

[0034] Step S102: Based on the state of the brake pedal depth signal and the state of the power assist motor position signal, determine the braking torque control strategy. The braking torque control strategy can be either braking control using the hydraulic torque of the purely mechanical master cylinder and the motor feedback torque, or braking control using a combination of the hydraulic torque of the purely mechanical master cylinder, the motor feedback torque, and the compensated hydraulic braking torque from the hydraulic brake-by-wire system.

[0035] This invention embodiment considers the situation where the motor assist of the fully decoupled hydraulic brake-by-wire system fails. In this case, the assist motor cannot participate in pressure building operations, and the hydraulic circuit only generates basic mechanical torque through pressure building by the purely mechanical master cylinder. The four-wheel calipers rely solely on this mechanical torque for basic clamping. Therefore, regardless of the state of the brake pedal signal and the assist motor position signal, the corresponding braking torque control strategy must include the hydraulic torque of the purely mechanical master cylinder. Subsequently, the braking torque control strategy can be based on the state of the brake pedal depth signal and the state of the assist motor position signal. For example, if the assist motor position signal is in a failed state, braking control can be achieved through the hydraulic torque of the purely mechanical master cylinder and the motor feedback torque. In this case, the power limit of the motor feedback torque can be lifted to maximize the output feedback torque at the motor end, which is superimposed on the mechanical torque to compensate for the insufficient braking force of the purely mechanical torque and improve the deceleration of the vehicle. If the assist motor position signal is in a normal state, the hydraulic torque of the purely mechanical master cylinder and the hydraulic brake-by-wire system can be used to compensate for the hydraulic braking torque and improve the clamping force of the calipers. The motor feedback torque can also be combined to improve the deceleration of the vehicle, thus achieving braking control. This is only an example.

[0036] Step S103: Based on the vehicle's braking demand torque and the hydraulic torque of the pure mechanical master cylinder, determine the torque value of the motor feedback torque of the braking torque control strategy, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensation hydraulic braking torque, and perform braking control based on the braking torque control strategy.

[0037] In this embodiment of the invention, the required braking torque Tq of the vehicle can be calculated by combining parameters such as the current brake pedal travel, vehicle speed, and ground adhesion coefficient. The hydraulic torque T of the pure mechanical master cylinder can be calculated by the brake pedal travel and pedal force. Correspondingly, the torque value Tt = Tq - T of the motor feedback torque of the braking torque control strategy can be calculated. Alternatively, when the vehicle braking is jointly participated by the motor feedback torque, the compensated hydraulic braking torque, and the pure mechanical master cylinder hydraulic torque, the priority of the motor feedback torque in braking is set higher than that of the compensated hydraulic braking torque of the hydraulic brake-by-wire system. The priority of the compensated hydraulic braking torque of the hydraulic brake-by-wire system in braking is higher than that of the pure mechanical braking torque. In this case, the motor feedback torque can be calculated based on the current brake pedal travel. Then, the compensated hydraulic braking torque value T0 = Tq - Tt - T of the hydraulic brake-by-wire system can be calculated. Finally, braking control can be performed based on the braking torque control strategy determined above.

[0038] The braking control method provided by this invention, in response to the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, acquires the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's assist motor, determines the state of these two signals, and then determines a braking torque control strategy based on the state of these two signals. The braking torque control strategy can be achieved through braking control using the hydraulic torque of the pure mechanical master cylinder and the motor feedback torque, or through a combination of the hydraulic torque of the pure mechanical master cylinder, the motor feedback torque, and the hydraulic brake-by-wire system's compensating hydraulic braking torque. Based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque, the torque value of the motor feedback torque of the braking torque control strategy is determined; alternatively, the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system's compensating hydraulic braking torque are determined separately, and braking control is performed based on the braking torque control strategy. This achieves the selection of at least one of the motor feedback torque and the compensating hydraulic braking torque for auxiliary braking based on the current signal state, solving the problems of deteriorated pedal feel and reduced deceleration after the failure of the motor assist in a fully decoupled hydraulic brake-by-wire system, thus improving vehicle safety.

[0039] This embodiment provides a braking control method that can be used in the controller of the aforementioned vehicle, which is equipped with a hydraulic brake-by-wire system and a drive motor. Figure 2 This is a flowchart of a braking control method according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: In response to the failure of the motor assist in the fully decoupled hydraulic brake-by-wire system, acquire the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's assist motor, and determine the status of the brake pedal depth signal and the assist motor position signal. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0040] Step S202: Based on the state of the brake pedal depth signal and the state of the power assist motor position signal, determine the braking torque control strategy. The braking torque control strategy can be either braking control using the hydraulic torque of the purely mechanical master cylinder and the motor feedback torque, or braking control using a combination of the hydraulic torque of the purely mechanical master cylinder, the motor feedback torque, and the compensated hydraulic braking torque from the hydraulic brake-by-wire system.

[0041] Specifically, step S202 includes: Step S2021: If the brake pedal depth signal is in a normal state, but the power assist motor position signal is in a failed state, determine that the braking torque control strategy is to control the brakes by using the hydraulic torque of the pure mechanical master cylinder and the feedback torque of the motor.

[0042] Step S2022: If both the brake pedal depth signal and the power assist motor position signal are in normal condition, the braking torque control strategy is determined to be a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque control, and hydraulic brake-by-wire system compensation hydraulic braking torque for braking control.

[0043] This invention can determine whether the brake pedal depth signal is normal. If the brake pedal depth signal is normal, it can further determine whether the power assist motor position signal is normal. If the power assist motor position signal fails, the motor feedback torque power limitation is released, and the braking torque control strategy is determined to be a combination of motor feedback torque and pure mechanical master cylinder hydraulic torque for braking control. The priority of motor feedback torque in braking is higher than that of pure mechanical braking torque. If the power assist motor position signal is normal, the hydraulic brake-by-wire system motor compensation pressure build-up function can be activated, and the braking torque control strategy is determined to be a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque control, and hydraulic brake-by-wire system compensated hydraulic braking torque for braking control to improve vehicle deceleration. Among these, the priority of motor braking feedback torque in braking is higher than that of hydraulic brake-by-wire system compensated hydraulic braking torque, and the priority of hydraulic brake-by-wire system compensated hydraulic braking torque is higher than that of pure mechanical master cylinder hydraulic torque. The process for selecting the braking torque control strategy is described in [link to documentation]. Figure 3 As shown.

[0044] When both signals are normal, this invention activates the motor compensation pressure building function, which improves the vehicle deceleration through three-level torque coordination. When the power assist motor position signal fails, it uses a combination of motor feedback torque and pure mechanical master cylinder hydraulic torque for braking control to compensate for the lack of mechanical torque.

[0045] In one alternative implementation, if the brake pedal depth signal is in a failed state, the braking control of the vehicle's four-wheel calipers is performed by the hydraulic torque of the purely mechanical master cylinder.

[0046] In this embodiment of the invention, when the brake pedal depth signal is determined to be in a failed state, the vehicle braking is only generated by the hydraulic torque of the purely mechanical master cylinder through the clamping of the four wheel calipers to produce the deceleration of the entire vehicle.

[0047] This invention enables braking control of the vehicle's four-wheel calipers through the hydraulic torque of the purely mechanical master cylinder when the brake pedal depth signal is in a failed state. This provides a backup braking function in the event of a failure, eliminates the risk of complete brake failure, and ensures vehicle braking stability.

[0048] Step S203: Based on the vehicle's braking demand torque and the hydraulic torque of the pure mechanical master cylinder, determine the torque value of the motor feedback torque of the braking torque control strategy, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensation hydraulic braking torque, and perform braking control based on the braking torque control strategy.

[0049] Specifically, when the brake pedal depth signal is normal but the power assist motor position signal is ineffective, braking control is determined to be based on a combination of the hydraulic torque of the pure mechanical master cylinder and the motor feedback torque. The following steps are then used to determine the motor feedback torque value for the braking torque control strategy based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque: Obtain the current brake pedal travel; determine the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel; calculate the difference between the vehicle's braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain the first compensating braking torque; determine the available motor feedback torque based on the preset mapping relationship between the brake pedal travel and the available motor feedback torque; and determine the minimum torque value between the first compensating braking torque and the available motor feedback torque as the motor feedback torque value.

[0050] In this embodiment of the invention, a pre-calibrated mapping relationship is established between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque and the available motor feedback torque. The form of this mapping relationship is not limited; it can be a formula relating the brake pedal travel to the available pure mechanical master cylinder hydraulic torque and the available motor feedback torque, or it can be a directly calibrated mapping curve corresponding to the brake pedal travel to the available pure mechanical master cylinder hydraulic torque and the available motor feedback torque. (See [link]). Figure 4 As shown, the current brake pedal travel can then be obtained. From the above-calibrated mapping curve, the corresponding available pure mechanical master cylinder hydraulic torque is determined. Then, the difference between the vehicle braking demand torque and the available pure mechanical master cylinder hydraulic torque is calculated to obtain the first compensating braking torque. Finally, from the above-calibrated mapping curve, the available motor feedback torque corresponding to the current brake pedal travel is determined.

[0051] The present invention can then determine the relationship between the first compensating braking torque and the available motor feedback torque, and directly select the minimum torque value as the torque value of the motor feedback torque. This can not only meet the braking requirements of the whole vehicle, but also ensure that the motor feedback torque does not exceed its own available upper limit, thus avoiding the problems of motor overload and feedback failure.

[0052] This invention uses mechanical hydraulic torque as the basic braking force to provide the core braking force, and motor feedback torque as the compensating braking force. This ensures the braking performance of the whole vehicle, and reduces energy loss during braking within the range of the motor's usability, thus balancing braking performance and energy saving.

[0053] In one optional implementation, before determining the available hydraulic torque of the pure mechanical master cylinder based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque and the current brake pedal travel, it can also be determined whether the current brake pedal travel is in the idle travel stage; if the current brake pedal travel is in the idle travel stage, the vehicle braking demand torque or the available motor feedback torque is determined as the torque value of the motor feedback torque; if the current brake pedal travel has completed the idle travel stage, the step of determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque and the current brake pedal travel is executed.

[0054] In this embodiment of the invention, when braking control is achieved by combining the hydraulic torque of the purely mechanical master cylinder and the regenerative torque of the electric motor, it is considered that when the driver depresses the pedal, the ECU detects the braking intention and immediately releases the power limitation of the regenerative torque of the electric motor. During the first few millimeters to several centimeters of pedal depressing, the brake pedal is in a free-travel phase. This free-travel phase must be completed first to eliminate the gap before the driver's pedal force can effectively drive the master cylinder to build pressure, and only then will the purely mechanical master cylinder hydraulic torque be generated. See [link to relevant documentation]. Figure 4 As shown, before determining the available pure mechanical master cylinder hydraulic torque, it is also possible to determine whether the current brake pedal travel is in the no-travel phase.

[0055] In this embodiment of the invention, if it is determined that the current brake pedal travel is in the idle travel stage, the hydraulic torque of the purely mechanical master cylinder is zero. At this time, the available motor feedback torque can be determined based on the current brake pedal travel. Then, the minimum torque value between the available motor feedback torque and the vehicle's braking demand torque is determined as the torque value of the motor feedback torque. This allows the motor feedback torque to intervene in braking first during the idle travel stage, eliminating braking lag caused by the idle travel and improving braking safety. If it is determined that the current brake pedal travel has completed the idle travel stage, the hydraulic torque of the purely mechanical master cylinder can be determined based on the current brake pedal travel. Then, the first compensating braking torque is calculated. The minimum torque value between the first compensating braking torque and the available motor feedback torque is determined as the torque value of the motor feedback torque.

[0056] This invention sets up motor feedback torque braking during the idle stroke stage to eliminate braking lag caused by the idle stroke and improve braking safety. After the idle stroke is completed, the coordinated compensation of hydraulic torque of mechanical master cylinder and motor feedback torque is activated to achieve torque control that perfectly matches the actual working state of the braking system.

[0057] In one optional implementation, when both the brake pedal depth signal and the power assist motor position signal are in a normal state, it is determined that braking control is performed by combining the hydraulic torque of the pure mechanical master cylinder, the motor feedback torque control, and the hydraulic brake-by-wire system's compensated hydraulic braking torque. This can be achieved by the following steps, based on the vehicle's braking demand torque and the pure mechanical master cylinder hydraulic torque, to determine the values ​​of the motor feedback torque and the hydraulic brake-by-wire system's compensated hydraulic braking torque for the braking torque control strategy: obtaining the current brake pedal travel; determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel; calculating the difference between the vehicle's braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain the second compensated braking torque; obtaining the available motor feedback torque based on the preset mapping relationship between the brake pedal travel and the available motor feedback torque; if the second compensated braking torque is not greater than the available motor feedback torque, determining the second compensated braking torque as the motor feedback torque value, and setting the hydraulic brake-by-wire system's compensated hydraulic braking torque value to zero.

[0058] In this embodiment of the invention, when both the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's power assist motor are normal, the hydraulic brake-by-wire system's motor compensation pressure-building function is activated to obtain the current brake pedal travel, based on... Figure 4 The mapping curve shown is used to obtain the vehicle's braking torque requirement corresponding to the current brake pedal travel (i.e., Figure 4 The solid line in the diagram represents the mapping curve, and the available pure mechanical master cylinder hydraulic torque is used. Then, the difference between the vehicle braking demand torque and the available pure mechanical master cylinder hydraulic torque is calculated to obtain the second compensating braking torque. Then, based on the mapping curve of the brake pedal travel and the available motor feedback torque, the available motor feedback torque is determined. Since the priority of the set motor feedback torque in braking is higher than the hydraulic brake-by-wire system compensating hydraulic braking torque, the second compensating braking torque and the available motor feedback torque can be compared first. If the second compensating braking torque is not greater than the available motor feedback torque, it means that the motor feedback torque can meet the vehicle braking needs. Then, the second compensating braking torque can be determined as the torque value of the motor feedback torque, and the torque value of the hydraulic brake-by-wire system compensating hydraulic braking torque is set to zero.

[0059] This invention is designed to allow the motor's regenerative torque to prioritize compensating for braking needs beyond the mechanical hydraulic torque, thereby maximizing the energy-saving advantages of motor regenerative braking and reducing the workload of the hydraulic drive-by-wire system.

[0060] In one optional implementation, if the second compensating braking torque is greater than the available motor feedback torque, the available motor feedback torque is determined as the torque value of the motor feedback torque; the difference between the second compensating braking torque and the available motor feedback torque is calculated to obtain the first hydraulic compensating torque; the first hydraulic compensating torque is determined as the torque value of the hydraulic brake-by-wire system compensating for the hydraulic braking torque.

[0061] In this embodiment of the invention, if it is determined that the second compensating braking torque is greater than the available motor feedback torque, see [reference needed]. Figure 4 The shaded area shown indicates that the available motor feedback torque can be determined as the torque value of the motor feedback torque. Then, the difference between the second compensating braking torque and the available motor feedback torque is calculated to obtain the first hydraulic compensating torque. This first hydraulic compensating torque is determined as the torque value of the hydraulic brake-by-wire system compensating for the hydraulic braking torque, i.e., T0 = Tq - Tt - T. The torque determination logic can be found in [reference needed]. Figure 5 As shown.

[0062] This invention ensures that the braking requirements of the entire vehicle are fully covered by quantitatively calculating the difference and accurately supplementing it by the hydraulic drive-by-wire system after the motor feedback torque reaches the upper limit of usability.

[0063] In one optional implementation, if the current brake pedal travel is in the no-travel phase, the magnitudes of the vehicle's braking demand torque and the available motor feedback torque are determined; if the vehicle's braking demand torque is not greater than the available motor feedback torque, the vehicle's braking demand torque is determined as the torque value of the motor feedback torque.

[0064] In this embodiment of the invention, it is considered that during the first few millimeters to several centimeters of the brake pedal being pressed, the brake pedal is in the idle travel phase. This idle travel must be completed first to eliminate the gap before the driver's pedal force can effectively drive the master cylinder to build pressure, and only then will the purely mechanical master cylinder hydraulic torque be generated. Therefore, when the current brake pedal travel is in the idle travel phase, the magnitude of the vehicle's required braking torque and the available motor feedback torque can be determined. If the vehicle's required braking torque is not greater than the available motor feedback torque, the vehicle's required braking torque is determined as the torque value of the motor feedback torque, and the torque value of the hydraulic brake-by-wire system compensating for the hydraulic braking torque is set to zero.

[0065] This invention directly responds to braking demand through motor feedback torque during the idle stroke phase, which not only fills the braking force gap during the idle stroke but also avoids excessive motor feedback, thus achieving synchronous connection between braking intention and braking execution.

[0066] In one optional implementation, if the vehicle braking demand torque is greater than the available motor feedback torque, the available motor feedback torque is determined as the torque value of the motor feedback torque; the difference between the vehicle braking demand torque and the available motor feedback torque is calculated to obtain the second hydraulic compensation torque; the second hydraulic compensation torque is determined as the torque value of the hydraulic brake-by-wire system to compensate for the hydraulic braking torque.

[0067] In this embodiment of the invention, if it is determined that the vehicle braking demand torque is greater than the available motor feedback torque, the available motor feedback torque is determined as the torque value of the motor feedback torque; and the difference between the vehicle braking demand torque and the available motor feedback torque is calculated to obtain the second hydraulic compensation torque; the second hydraulic compensation torque is determined as the torque value of the hydraulic brake-by-wire system to compensate for the hydraulic braking torque, thereby covering high braking demand scenarios and covering the full supply of braking force through full motor feedback and hydraulic compensation.

[0068] This embodiment also provides a vehicle, such as Figure 6 As shown, the vehicle is equipped with a hydraulic brake-by-wire system 61, a drive motor 62, and a controller 63. The controller 63 includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes these computer instructions to perform the braking control method. For detailed descriptions, please refer to the above embodiments; they will not be repeated here.

[0069] This embodiment also provides a braking control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0070] This embodiment provides a braking control device. The vehicle is equipped with a hydraulic brake-by-wire system and a drive motor, such as... Figure 7As shown, the system includes: a signal acquisition module 701, used to acquire the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system's assist motor in response to the failure of the fully decoupled hydraulic brake-by-wire system's motor assist, and to determine the state of the brake pedal depth signal and the assist motor position signal; a brake control strategy determination module 702, used to determine a brake torque control strategy based on the state of the brake pedal depth signal and the state of the assist motor position signal, wherein the brake torque control strategy is to perform brake control through the pure mechanical master cylinder hydraulic torque and the motor feedback torque, or to perform brake control through a combination of the pure mechanical master cylinder hydraulic torque, the motor feedback torque, and the hydraulic brake-by-wire system's compensated hydraulic brake torque; and a torque value calculation module 703, used to determine the torque value of the motor feedback torque of the brake torque control strategy based on the vehicle's brake demand torque and the pure mechanical master cylinder hydraulic torque, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system's compensated hydraulic brake torque, and to perform brake control based on the brake torque control strategy.

[0071] In some optional implementations, the braking control strategy determination module 702 includes: a first control strategy determination unit, configured to determine the braking torque control strategy as braking control through a combination of pure mechanical master cylinder hydraulic torque and motor feedback torque if the brake pedal depth signal is in a normal state but the power assist motor position signal is in a failed state; and a second control strategy determination unit, configured to determine the braking torque control strategy as braking control through a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque control, and hydraulic brake-by-wire system compensated hydraulic braking torque if both the brake pedal depth signal and the power assist motor position signal are in a normal state.

[0072] In some alternative implementations, the braking control device further includes a purely mechanical braking control module, used to control the braking of the vehicle's four-wheel calipers by means of purely mechanical master cylinder hydraulic torque if the brake pedal depth signal is in a failed state.

[0073] In some optional implementations, if the brake pedal depth signal is in a normal state but the power assist motor position signal is in a failed state, the torque value calculation module 703 includes: a pedal travel acquisition unit for acquiring the current brake pedal travel; a mechanical torque determination unit for determining the available pure mechanical master cylinder hydraulic torque based on a preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque and the current brake pedal travel; a first compensation brake torque determination unit for calculating the difference between the vehicle's braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain a first compensation brake torque; an available motor feedback torque calculation unit for determining the available motor feedback torque based on a preset mapping relationship between the brake pedal travel and the available motor feedback torque; and a motor feedback torque determination unit for determining the minimum torque value between the first compensation brake torque and the available motor feedback torque as the torque value of the motor feedback torque.

[0074] In some optional embodiments, before determining the available hydraulic torque of the pure mechanical master cylinder based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, the brake control device further includes: an idle travel phase determination module, used to determine whether the current brake pedal travel is in the idle travel phase; a state determination module, used if the current brake pedal travel is in the idle travel phase; a motor feedback torque determination module, used to determine the vehicle braking demand torque or available motor feedback torque as the torque value of the motor feedback torque; and a step execution module, used if the current brake pedal travel has completed the idle travel phase, to execute the step of determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel.

[0075] In some optional implementations, if both the brake pedal depth signal and the power assist motor position signal are in a normal state, the torque value calculation module 703 includes: a pedal travel unit for acquiring the current brake pedal travel; a mechanical torque determination unit for determining the available pure mechanical master cylinder hydraulic torque based on a preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque and the current brake pedal travel; a second compensation torque determination unit for calculating the difference between the vehicle braking demand torque and the available pure mechanical master cylinder hydraulic torque to obtain the second compensation braking torque; a motor feedback torque determination unit for obtaining the available motor feedback torque based on a preset mapping relationship between the brake pedal travel and the available motor feedback torque; and a torque setting unit for determining the second compensation braking torque as the torque value of the motor feedback torque if the second compensation braking torque is not greater than the available motor feedback torque, and setting the torque value of the hydraulic brake-by-wire system compensation hydraulic braking torque to zero.

[0076] In some optional embodiments, the braking control device further includes: a motor feedback torque setting module, used to determine the available motor feedback torque as the torque value of the motor feedback torque if the second compensating braking torque is greater than the available motor feedback torque; a first hydraulic compensation torque calculation module, used to calculate the difference between the second compensating braking torque and the available motor feedback torque to obtain the first hydraulic compensation torque; and a hydraulic drive-by-wire torque setting module, used to determine the first hydraulic compensation torque as the torque value of the hydraulic drive-by-wire braking system to compensate for the hydraulic braking torque.

[0077] In some optional embodiments, the braking control device further includes: a pedal travel module, used if the current brake pedal travel is in the no-travel phase; a magnitude determination module, used to determine the magnitude of the vehicle braking demand torque and the available motor feedback torque; and a motor feedback torque determination module, used to determine the vehicle braking demand torque as the torque value of the motor feedback torque if the vehicle braking demand torque is not greater than the available motor feedback torque.

[0078] In some optional embodiments, the braking control device further includes: a motor feedback torque determination module, used to determine the available motor feedback torque as the torque value of the motor feedback torque if the vehicle braking demand torque is greater than the available motor feedback torque; a second hydraulic compensation torque determination module, used to calculate the difference between the vehicle braking demand torque and the available motor feedback torque to obtain the second hydraulic compensation torque; and a hydraulic compensation torque determination module, used to determine the second hydraulic compensation torque as the torque value of the hydraulic brake-by-wire system to compensate for the hydraulic braking torque.

[0079] The braking control device provided in this embodiment of the invention can execute the braking control method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0080] Figure 8 This is a schematic diagram of the structure of a controller in a vehicle provided by an embodiment of the present invention.

[0081] The following is a detailed reference. Figure 8 The diagram illustrates a structural schematic suitable for implementing a controller in an embodiment of the present invention. The controller may include a processor (e.g., a central processing unit, a graphics processing unit, etc.) 801, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 802 or a program loaded from memory 808 into random access memory (RAM) 803. The RAM 803 also stores various programs and data required for controller operation. The processor 801, ROM 802, and RAM 803 are interconnected via bus 804. An input / output (I / O) interface 805 is also connected to bus 804.

[0082] Typically, the following devices can be connected to I / O interface 805: input devices 806 including, for example, a touchscreen, touchpad, keyboard, mouse, camera, microphone, accelerometer, gyroscope, etc.; output devices 807 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; memory 808 including, for example, magnetic tape, hard disk, etc.; and communication devices 809. Communication device 809 allows the controller to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 8 A controller with various devices is shown, but it should be understood that it is not required to implement or have all of the devices shown, and may alternatively implement or have more or fewer devices.

[0083] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 809, or installed from a memory 808, or installed from a ROM 802. When the computer program is executed by the processor 801, it performs the functions defined in the braking control method of the embodiments of the present invention.

[0084] Figure 8 The controller shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0085] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the braking control method shown in the above embodiments is implemented.

[0086] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0087] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A braking control method, employing a controller in a vehicle, said vehicle being equipped with a hydraulic brake-by-wire system and a drive motor, characterized in that, The method includes: In response to the failure of the motor assist in the fully decoupled hydraulic brake-by-wire system, the system acquires the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system assist motor, and determines the state of the brake pedal depth signal and the position signal of the assist motor. Based on the state of the brake pedal depth signal and the state of the power assist motor position signal, a braking torque control strategy is determined. The braking torque control strategy is to control braking by using the hydraulic torque of the pure mechanical master cylinder and the feedback torque of the motor, or to control braking by combining the hydraulic torque of the pure mechanical master cylinder, the feedback torque of the motor and the compensated hydraulic braking torque of the hydraulic brake-by-wire system. Based on the vehicle's braking demand torque and the hydraulic torque of the purely mechanical master cylinder, the torque value of the motor feedback torque of the braking torque control strategy is determined, or the torque values ​​of the motor feedback torque and the hydraulic brake-by-wire system compensation hydraulic braking torque are determined respectively, and braking control is performed based on the braking torque control strategy.

2. The method according to claim 1, characterized in that, The determination of the braking torque control strategy based on the state of the brake pedal depth signal and the state of the power assist motor position signal includes: If the brake pedal depth signal is in a normal state, but the power assist motor position signal is in a failed state, the brake torque control strategy is determined to be to control the brakes through the hydraulic torque of the pure mechanical master cylinder and the feedback torque of the motor. If both the brake pedal depth signal and the power assist motor position signal are in normal condition, the braking torque control strategy is determined to be a combination of pure mechanical master cylinder hydraulic torque, motor feedback torque control, and hydraulic brake-by-wire system compensation hydraulic braking torque for braking control.

3. The method according to claim 2, characterized in that, The method further includes: If the brake pedal depth signal is ineffective, the braking control of the vehicle's four wheel calipers is achieved through the hydraulic torque of the purely mechanical master cylinder.

4. The method according to claim 2, characterized in that, If the brake pedal depth signal is normal, but the power assist motor position signal is invalid, the torque value of the motor feedback torque of the braking torque control strategy is determined based on the vehicle's braking torque demand and the hydraulic torque of the purely mechanical master cylinder, including: Get the current brake pedal travel; Based on the mapping relationship between the preset brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, the available pure mechanical master cylinder hydraulic torque is determined. The difference between the vehicle's braking torque requirement and the available pure mechanical master cylinder hydraulic torque is calculated to obtain the first compensating braking torque. Based on the mapping relationship between the preset brake pedal travel and the available motor feedback torque, the available motor feedback torque is determined; The minimum torque value between the first compensated braking torque and the available motor feedback torque is determined as the torque value of the motor feedback torque.

5. The method according to claim 4, characterized in that, Before determining the available hydraulic torque of the pure mechanical master cylinder based on the mapping relationship between the preset brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, the method further includes: Determine whether the current brake pedal travel is in the free travel phase; If the current brake pedal travel is in the no-travel phase; The torque value of the motor feedback torque is determined by the vehicle's braking torque requirement or the available motor feedback torque. If the current brake pedal travel completes the idle travel phase, the step of determining the available pure mechanical master cylinder hydraulic torque based on the preset mapping relationship between the brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, is executed.

6. The method according to claim 2, characterized in that, If both the brake pedal depth signal and the power assist motor position signal are in normal condition, based on the vehicle's braking torque demand and the purely mechanical master cylinder hydraulic torque, determine the motor feedback torque and the torque values ​​of the hydraulic brake-by-wire system compensating for the hydraulic braking torque of the braking torque control strategy, including: Get the current brake pedal travel; Based on the mapping relationship between the preset brake pedal travel and the available pure mechanical master cylinder hydraulic torque, and the current brake pedal travel, the available pure mechanical master cylinder hydraulic torque is determined. The difference between the vehicle's braking torque requirement and the available pure mechanical master cylinder hydraulic torque is calculated to obtain the second compensating braking torque. Based on the mapping relationship between the preset brake pedal travel and the available motor feedback torque, the available motor feedback torque is obtained; If the second compensating braking torque is not greater than the available motor feedback torque, the second compensating braking torque is determined as the torque value of the motor feedback torque, and the torque value of the hydraulic brake-by-wire system compensating for the hydraulic braking torque is set to zero.

7. The method according to claim 6, characterized in that, The method further includes: If the second compensated braking torque is greater than the available motor feedback torque, the available motor feedback torque is determined as the torque value of the motor feedback torque; The difference between the second compensated braking torque and the available motor feedback torque is calculated to obtain the first hydraulic compensated torque; The first hydraulic compensation torque is determined as the torque value of the hydraulic brake-by-wire system that compensates for the hydraulic braking torque.

8. The method according to claim 6, characterized in that, The method further includes: If the current brake pedal travel is in the no-travel phase; Determine the vehicle's braking torque requirement and the magnitude of the available motor feedback torque; If the vehicle's braking torque requirement is not greater than the available motor feedback torque, the vehicle's braking torque requirement is determined as the torque value of the motor feedback torque.

9. The method according to claim 8, characterized in that, The method further includes: If the vehicle's braking torque requirement is greater than the available motor feedback torque, the available motor feedback torque is determined as the torque value of the motor feedback torque. The difference between the vehicle's braking torque demand and the available motor feedback torque is calculated to obtain the second hydraulic compensation torque; The second hydraulic compensation torque is determined as the torque value of the hydraulic brake-by-wire system for compensating for the hydraulic braking torque.

10. A braking control device, employing a controller in a vehicle, said vehicle being equipped with a hydraulic brake-by-wire system and a drive motor, characterized in that, The device includes: The signal acquisition module is used to acquire the brake pedal depth signal and the position signal of the hydraulic brake-by-wire system assist motor in response to the failure of the fully decoupled hydraulic brake-by-wire system motor, and to determine the state of the brake pedal depth signal and the position signal of the assist motor. The braking control strategy determination module is used to determine the braking torque control strategy based on the state of the brake pedal depth signal and the state of the power assist motor position signal. The braking torque control strategy is to perform braking control by using the hydraulic torque of the pure mechanical master cylinder and the feedback torque of the motor, or to perform braking control by combining the hydraulic torque of the pure mechanical master cylinder, the feedback torque of the motor and the compensated hydraulic braking torque of the hydraulic brake-by-wire system. The torque value calculation module is used to determine the torque value of the motor feedback torque of the braking torque control strategy based on the vehicle braking demand torque and the hydraulic torque of the pure mechanical master cylinder, or the torque values ​​of the motor feedback torque and the hydraulic braking torque compensated by the hydraulic brake-by-wire system, and to perform braking control based on the braking torque control strategy.

11. A vehicle, characterized in that, The vehicle is equipped with a hydraulic brake-by-wire system, a drive motor, and a controller. The controller includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the braking control method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the braking control method according to any one of claims 1 to 9.

Images