Pneumoelectric composite braking method and device of vehicle, vehicle and storage medium

Abstract

The invention relates to the technical field of vehicles, in particular to a pneumoelectric composite braking method and device of a vehicle, the vehicle and a storage medium, and the method comprises the steps that the brake pedal opening degree of the current vehicle, the vehicle weight of the current vehicle and the motor capacity of the current vehicle are obtained; according to the brake pedal opening degree of the current vehicle, the vehicle weight of the current vehicle and the motor capacity of the current vehicle, the motor braking distribution proportion of the current vehicle and the air pressure braking distribution proportion of the current vehicle are determined; and based on the motor braking distribution proportion of the current vehicle and the air pressure braking distribution proportion of the current vehicle, pneumatic-electric composite braking is conducted on the current vehicle. Therefore, the problems that an existing braking method is not beneficial to driving safety, the braking efficiency is reduced and the like are solved, auxiliary braking is carried out as much as possible by calling motor intervention on the premise that the driving safety is guaranteed, use of a wheel end brake is reduced, meanwhile, abrasion of a friction plate is reduced, and the energy recovery efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and particularly to a pneumatic-electric composite braking method, device, vehicle and storage medium for a vehicle. Background Art

[0002] With the development of the automotive industry and the progress of technology, new energy vehicle models have gradually become the main trend of future development. New energy vehicle models mainly include types such as gaseous hydrogen, liquid hydrogen, and pure electric. Compared with traditional fuel vehicle models, they have higher environmental friendliness and economy. However, since new energy vehicle models do not have engines and retarders in traditional fuel vehicle models, traditional auxiliary braking solutions are no longer applicable, resulting in new challenges for new energy vehicle models in terms of auxiliary braking.

[0003] Currently, the auxiliary braking forms of traditional energy vehicles mainly include in-cylinder engine braking, exhaust braking, and retarder braking. The braking efficiency of in-cylinder engine braking and exhaust braking is relatively low, especially in cases where rapid deceleration is required, and their effects are limited. Although retarder braking has a high braking efficiency, it has problems such as high cost, serious heat generation, and a relatively large volume occupying chassis space, which limits its application in new energy vehicle models.

[0004] In contrast, new energy vehicle models mainly adopt separate pneumatic braking and coasting motor braking (i.e., energy recovery). However, in working conditions such as long downhill slopes or long-term continuous braking, continuous pneumatic braking will cause the temperature of the brake to rise, the friction pads to wear more severely, and the braking performance to decline, thus affecting driving safety. In addition, although coasting motor braking can recover some energy, its energy recovery efficiency is relatively low, and it cannot maximize the use of auxiliary braking performance, which urgently needs to be solved. Summary of the Invention

[0005] The present application provides a pneumatic-electric composite braking method, device, vehicle and storage medium for a vehicle to solve problems such as the existing braking methods being unfavorable for driving safety and the decline of braking performance. On the premise of ensuring driving safety, by invoking the motor to intervene for as much auxiliary braking as possible, the use of wheel-end brakes is reduced, the wear of friction pads is reduced, and the energy recovery performance is improved.

[0006] The first aspect embodiment of the present application provides a pneumatic-electric composite braking method for a vehicle, including the following steps:

[0007] Obtain the braking pedal opening degree of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle;

[0008] Determine the electric braking distribution ratio of the current vehicle and the pneumatic braking distribution ratio of the current vehicle according to the braking pedal opening degree of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle;

[0009] Perform air-electric composite braking on the current vehicle based on the electric braking distribution ratio of the current vehicle and the air braking distribution ratio of the current vehicle.

[0010] According to an embodiment of the present application, determining the electric braking distribution ratio of the current vehicle and the air braking distribution ratio of the current vehicle according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle includes:

[0011] Determine a target required deceleration according to the brake pedal opening, and determine the maximum achievable deceleration of the current vehicle according to the motor capacity;

[0012] If the vehicle weight of the current vehicle is less than or equal to a first preset threshold, and the target required deceleration is less than or equal to a second preset threshold, then when the maximum achievable deceleration is greater than or equal to the target required deceleration, use the target required deceleration as the first initial electric braking deceleration of the current vehicle;

[0013] Judge whether the vehicle speed of the current vehicle is greater than a third preset threshold. If the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle. If the wheel slip ratio is greater than a fourth preset threshold, calculate the deceleration reduced and allocated to the electric braking to obtain a reduced first electric braking deceleration, and update the first initial electric braking deceleration based on the first electric braking deceleration;

[0014] If the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold. If the duration is greater than or equal to a fifth preset threshold, calculate the actual executed deceleration of the current vehicle;

[0015] If the actual executed deceleration is greater than the target required deceleration, when the error value between the actual executed deceleration and the target required deceleration is greater than a sixth preset threshold, calculate the deceleration reduced and allocated to the electric braking to obtain a reduced second electric braking deceleration, and update the first initial electric braking deceleration based on the second electric braking deceleration. Otherwise, calculate the deceleration increased and allocated to the electric braking, and update the first initial electric braking deceleration based on the increased third electric braking deceleration.

[0016] According to an embodiment of the present application, after determining that the vehicle weight of the current vehicle is less than or equal to the first preset threshold and the target required deceleration is less than or equal to the second preset threshold, it further includes:

[0017] If the maximum achievable deceleration is less than the target required deceleration, allocate a second initial electric motor braking deceleration to the current vehicle and allocate an initial pneumatic braking deceleration to the current vehicle;

[0018] If the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle. If the wheel slip ratio is greater than the fourth preset threshold, calculate the deceleration reduced and allocated to the pneumatic braking to obtain a reduced first pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the first pneumatic braking deceleration;

[0019] If the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold. If the duration is greater than or equal to the fifth preset threshold, calculate the actual executed deceleration of the current vehicle;

[0020] If the error value between the actual executed deceleration and the target required deceleration is greater than the sixth preset threshold, when the actual executed deceleration is greater than the target required deceleration, calculate the deceleration reduced and allocated to the pneumatic braking to obtain a reduced second pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the second pneumatic braking deceleration. Otherwise, calculate the deceleration increased and allocated to the pneumatic braking, and update the initial pneumatic braking deceleration based on the increased third pneumatic braking deceleration.

[0021] According to an embodiment of the present application, before obtaining the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle, it further includes:

[0022] Obtain the state of the pneumatic-electric composite braking management system and the enable switch state of the current vehicle;

[0023] If the state of the pneumatic-electric composite braking management system is a fault-free state, the enable switch state is an on state, the current vehicle meets the preset preconditions for function activation, and the current vehicle is not in a preset emergency condition, control the current vehicle to activate the pneumatic-electric composite braking function;

[0024] Wherein, when the motor, transmission, wheel speed sensor, and brake pedal sensor of the current vehicle are not in a fault state, it is determined that the state of the pneumatic-electric composite braking management system of the current vehicle is the fault-free state.

[0025] According to an embodiment of the present application, the preconditions for activating the preset function are that the vehicle speed of the current vehicle is greater than or equal to a seventh preset threshold, the driveline state is in an engaged state, there is no motor braking torque, the accelerator pedal state is in a non-pressed state, and the brake pedal state is in a pressed state.

[0026] According to an embodiment of the present application, the preset emergency condition is that the opening degree of the brake pedal of the current vehicle is greater than or equal to an eighth preset threshold, and the speed at which the brake pedal is pressed is greater than or equal to a ninth preset threshold.

[0027] According to an embodiment of the present application, after controlling the current vehicle to activate the air-electric composite braking function, it further includes:

[0028] Continuously monitor the ignition switch state, enable switch state, vehicle speed of the current vehicle, driveline state, wheel state, brake pedal state, accelerator pedal state, and the state of the air-electric composite braking management system of the current vehicle;

[0029] If the ignition switch state of the current vehicle is in the off state, or the enable switch state is in the off state, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the driveline state is in the disengaged state, or the wheel state is in the locked state, or the brake pedal state is in the non-pressed state, or the accelerator pedal state is in the pressed state, or the state of the air-electric composite braking management system is in the fault state, then control the current vehicle to exit the air-electric composite braking function.

[0030] According to the air-electric composite braking method for a vehicle provided by an embodiment of the present application, determine the electric braking distribution ratio and the air braking distribution ratio of the current vehicle according to the brake pedal opening degree, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; perform air-electric composite braking on the current vehicle based on the electric braking distribution ratio and the air braking distribution ratio of the current vehicle. Thereby, problems such as the existing braking method being unfavorable for driving safety and the decline of braking efficiency are solved. On the premise of ensuring driving safety, by calling the motor to intervene for as much auxiliary braking as possible, the use of wheel-end brakes is reduced, the wear of friction plates is reduced, and the energy recovery efficiency is improved.

[0031] An embodiment of the second aspect of the present application provides an air-electric composite braking device for a vehicle, including:

[0032] An acquisition module, configured to acquire the brake pedal opening degree, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle;

[0033] A determination module, configured to determine an electric braking distribution ratio and a pneumatic braking distribution ratio of the current vehicle according to the braking pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle;

[0034] A pneumatic-electric composite braking module, configured to perform pneumatic-electric composite braking on the current vehicle based on the electric braking distribution ratio and the pneumatic braking distribution ratio of the current vehicle.

[0035] According to an embodiment of the present application, the determination module is configured to:

[0036] Determine a target required deceleration according to the braking pedal opening, and determine the maximum executable deceleration of the current vehicle according to the motor capacity;

[0037] If the vehicle weight of the current vehicle is less than or equal to a first preset threshold, and the target required deceleration is less than or equal to a second preset threshold, then when the maximum executable deceleration is greater than or equal to the target required deceleration, use the target required deceleration as the first initial electric braking deceleration of the current vehicle;

[0038] Judge whether the vehicle speed of the current vehicle is greater than a third preset threshold. If the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle. If the wheel slip ratio is greater than a fourth preset threshold, calculate the deceleration reduced to the electric braking to obtain a reduced first electric braking deceleration, and update the first initial electric braking deceleration based on the first electric braking deceleration;

[0039] If the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold. If the duration is greater than or equal to a fifth preset threshold, calculate the actual executed deceleration of the current vehicle;

[0040] If the actual executed deceleration is greater than the target required deceleration, when the error value between the actual executed deceleration and the target required deceleration is greater than a sixth preset threshold, calculate the deceleration reduced to the electric braking to obtain a reduced second electric braking deceleration, and update the first initial electric braking deceleration based on the second electric braking deceleration. Otherwise, calculate the deceleration increased to the electric braking, and update the first initial electric braking deceleration based on the increased third electric braking deceleration.

[0041] According to an embodiment of the present application, after determining that the vehicle weight of the current vehicle is less than or equal to a first preset threshold and the target required deceleration is less than or equal to a second preset threshold, the determining module is further configured to:

[0042] If the maximum executable deceleration is less than the target required deceleration, allocate a second initial electric motor braking deceleration to the current vehicle and allocate an initial pneumatic braking deceleration to the current vehicle;

[0043] If the vehicle speed of the current vehicle is greater than a third preset threshold, calculate the wheel slip ratio of the current vehicle. If the wheel slip ratio is greater than a fourth preset threshold, calculate the deceleration reduced to be allocated to the pneumatic braking to obtain a reduced first pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the first pneumatic braking deceleration;

[0044] If the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold. If the duration is greater than or equal to a fifth preset threshold, calculate the actual executed deceleration of the current vehicle;

[0045] If the error value between the actual executed deceleration and the target required deceleration is greater than a sixth preset threshold, when the actual executed deceleration is greater than the target required deceleration, calculate the deceleration reduced to be allocated to the pneumatic braking to obtain a reduced second pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the second pneumatic braking deceleration. Otherwise, calculate the deceleration increased to be allocated to the pneumatic braking, and update the initial pneumatic braking deceleration based on the increased third pneumatic braking deceleration.

[0046] According to an embodiment of the present application, before obtaining the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle, the obtaining module is further configured to:

[0047] Obtain the state of the pneumatic-electric composite braking management system and the state of the enable switch of the current vehicle;

[0048] If the state of the pneumatic-electric composite braking management system is a fault-free state, the state of the enable switch is an on state, the current vehicle meets the preconditions for activating the preset function, and the current vehicle is not in a preset emergency condition, control the current vehicle to activate the pneumatic-electric composite braking function;

[0049] Wherein, when the motor, transmission, wheel speed sensor, and brake pedal sensor of the current vehicle are not in a fault state, determine that the state of the pneumatic-electric composite braking management system of the current vehicle is the fault-free state.

[0050] According to an embodiment of the present application, the preconditions for activating the preset function are that the vehicle speed of the current vehicle is greater than or equal to a seventh preset threshold, the powertrain state is engaged, there is no motor braking torque, the accelerator pedal state is not depressed, and the brake pedal state is depressed.

[0051] According to an embodiment of the present application, the preset emergency condition is that the opening of the brake pedal of the current vehicle is greater than or equal to an eighth preset threshold, and the speed at which the brake pedal is depressed is greater than or equal to a ninth preset threshold.

[0052] According to an embodiment of the present application, after controlling the current vehicle to activate the air-electric composite braking function, the air-electric composite braking module is further configured to:

[0053] Continuously monitor the ignition switch state, enable switch state, vehicle speed of the current vehicle, powertrain state, wheel state, brake pedal state, accelerator pedal state, and air-electric composite braking management system state of the current vehicle;

[0054] If the ignition switch state of the current vehicle is in the off state, or the enable switch state is in the off state, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the powertrain state is in the disengaged state, or the wheel state is in the locked state, or the brake pedal state is not depressed, or the accelerator pedal state is depressed, or the air-electric composite braking management system state is in a fault state, then control the current vehicle to exit the air-electric composite braking function.

[0055] The air-electric composite braking device of the vehicle provided by the embodiment of the present application determines the electric braking distribution ratio and the air braking distribution ratio of the current vehicle according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; performs air-electric composite braking on the current vehicle based on the electric braking distribution ratio and the air braking distribution ratio of the current vehicle. Thereby, problems such as the existing braking method being unfavorable for driving safety and the decline of braking efficiency are solved. On the premise of ensuring driving safety, as much auxiliary braking as possible is performed by calling the motor to intervene, reducing the use of wheel-end brakes, reducing the wear of friction plates, and improving the energy recovery efficiency.

[0056] An embodiment of the third aspect of the present application provides a vehicle, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the program to implement the air-electric composite braking method of the vehicle as described in the above embodiment.

[0057] In a fourth aspect embodiment of the present application, a computer-readable storage medium is provided. The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the computer to execute the gas-electric composite braking method for a vehicle as described in the above embodiments.

[0058] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0060] Figure 1 is an architecture diagram of a gas-electric composite braking management system for a vehicle according to an embodiment of the present application;

[0061] Figure 2 is a flowchart of a gas-electric composite braking method for a vehicle provided according to an embodiment of the present application;

[0062] Figure 3 is a corresponding curve diagram of the braking pedal depth and the desired deceleration for a vehicle according to an embodiment of the present application;

[0063] Figure 4 is a flowchart of the gas-electric composite braking deceleration distribution for a vehicle according to an embodiment of the present application;

[0064] Figure 5 is a flowchart of a gas-electric composite braking method for a vehicle according to an embodiment of the present application;

[0065] Figure 6 is a block schematic diagram of a gas-electric composite braking device for a vehicle according to an embodiment of the present application;

[0066] Figure 7 is a schematic structural diagram of a vehicle provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0067] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0068] The gas-electric composite braking method, device, vehicle, and storage medium of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0069] Before introducing the gas-electric hybrid braking method of the vehicle according to the embodiments of the present application, first briefly introduce the gas-electric hybrid braking system of the vehicle involved in the gas-electric hybrid braking method of the vehicle of the present application.

[0070] Specifically, as Figure 1 shown, the gas-electric hybrid braking system of the vehicle of the present application includes three parts: an input signal, a controller, and an output signal. Among them, after the controller receives relevant input signals such as the motor, the transmission, the enable switch, the wheel speed sensor, and the brake pedal sensor, through the logical calculation of the controller, it controls the motor, the brake, and the instrument to execute relevant instructions through the output signal to achieve corresponding functions. The input signals mainly include: CAN (Controller Area Network) message input signals such as motor torque, motor speed, and driveline engagement status, and hardwired input signals such as wheel speed, function enable switch, brake pedal depth, and speed. The output signals mainly include: CAN message output signals such as function enable, function activation, and function failure for the instrument to display relevant indicator lights, torque request CAN message output signals for the motor to execute electric braking, and output air pressure private CAN message output signals for the brake to execute air pressure braking.

[0071] Next, introduce the gas-electric hybrid braking method of the vehicle based on the above gas-electric hybrid braking system of the vehicle proposed by the present application.

[0072] Specifically, Figure 2 is a schematic flow chart of a gas-electric hybrid braking method for a vehicle provided by an embodiment of the present application.

[0073] As Figure 2 shown, the gas-electric hybrid braking method of the vehicle includes the following steps:

[0074] In step S201, obtain the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle.

[0075] Specifically, in the embodiment of the present application, the brake pedal opening of the current vehicle can be obtained through an opening sensor, and the motor capacity of the current vehicle can also be obtained by reading the parameter data of the motor controller, such as key parameters of the motor such as the current torque, speed, and temperature. There is no specific limitation here.

[0076] Furthermore, in the embodiment of the present application, the current weight of the vehicle can also be calculated according to the acceleration and engine torque of the current vehicle. For example, the current weight of the vehicle can be calculated by the following formula:

[0077]

[0078] Wherein, G is the vehicle weight of the current vehicle, T is the engine torque, ig is the gear ratio of the transmission corresponding to the gear of the vehicle, io is the gear ratio of the final drive of the vehicle, vT is the mechanical efficiency of the vehicle's driveline, r is the rolling radius of the vehicle's tire, and a is the vehicle acceleration.

[0079] In step S202, the electric brake distribution ratio and the air brake distribution ratio of the current vehicle are determined according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle.

[0080] In step S203, the current vehicle is subjected to electro-pneumatic composite braking based on the electric brake distribution ratio and the air brake distribution ratio of the current vehicle.

[0081] Specifically, in some embodiments, determining the electric brake distribution ratio and the air brake distribution ratio of the current vehicle according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle includes: determining a target required deceleration according to the brake pedal opening, and determining the maximum achievable deceleration of the current vehicle according to the motor capacity; if the vehicle weight of the current vehicle is less than or equal to a first preset threshold and the target required deceleration is less than or equal to a second preset threshold, then when the maximum achievable deceleration is greater than or equal to the target required deceleration, taking the target required deceleration as the first initial electric brake deceleration of the current vehicle; judging whether the vehicle speed of the current vehicle is greater than a third preset threshold, if the vehicle speed of the current vehicle is greater than the third preset threshold, then calculating the wheel slip ratio of the current vehicle, if the wheel slip ratio is greater than a fourth preset threshold, then calculating the deceleration reduced for the electric brake to obtain a reduced first electric brake deceleration, and updating the first initial electric brake deceleration based on the first electric brake deceleration; if the wheel slip ratio is less than or equal to the fourth preset threshold, then obtaining the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold, if the duration is greater than or equal to a fifth preset threshold, then calculating the actual executed deceleration of the current vehicle; if the actual executed deceleration is greater than the target required deceleration, then when the error value between the actual executed deceleration and the target required deceleration is greater than a sixth preset threshold, calculating the deceleration reduced for the electric brake to obtain a reduced second electric brake deceleration, and updating the first initial electric brake deceleration based on the second electric brake deceleration, otherwise, calculating the deceleration increased for the electric brake, and updating the first initial electric brake deceleration based on the increased third electric brake deceleration.

[0082] Optionally, the first preset threshold may be 12 tons, the second preset threshold may be 0.2g, g = 9.8m / s 2, the third preset threshold may be 10 km / h, the fourth preset threshold may be 15%, the fifth preset threshold may be 20 ms, and the sixth preset threshold may be 10%. No specific limitation is made here.

[0083] Specifically, the embodiment of the present application introduces a correspondence curve between the brake pedal depth and the desired deceleration. As Figure 3 shown, according to the correspondence curve between the brake pedal depth and the desired deceleration, the same desired deceleration corresponds to the same brake pedal depth, so as to determine the target required deceleration according to the brake pedal opening. Among them, the correspondence curve between the brake pedal depth and the desired deceleration can be established in advance through experiments or computer simulations, which can ensure that the driver's brake pedal feeling is relatively unified when the vehicle is empty or fully loaded, and improve the riding comfort. In addition, the embodiment of the present application can also adjust the curve according to actual needs to change to a rough mode or a gentle mode. No specific limitation is made here.

[0084] Further, it is judged whether the vehicle weight of the current vehicle is less than or equal to the first preset threshold. If the vehicle weight of the current vehicle is less than or equal to the first preset threshold (such as 12 tons), it is further judged whether the target required deceleration is less than or equal to the second preset threshold (such as 0.2g, g = 9.8m / s 2 ), if the target required deceleration is less than or equal to the second preset threshold, the maximum executable deceleration a0 of the current vehicle is determined according to the motor capacity, and it is further judged whether the maximum executable deceleration is greater than or equal to the target required deceleration.

[0085] In addition, if the vehicle weight of the current vehicle is greater than the first preset threshold, or the target required deceleration is greater than the second preset threshold, it means that the vehicle weight of the whole vehicle is large, or the required deceleration of the current vehicle is large, and the brake system backup pressure p0 needs to be increased in advance (such as 0.2 bar for disc brakes and 0.4 bar for drum brakes), so as to shorten the air brake response time when the electric motor braking cannot meet the required deceleration and can supplement the air brake in time.

[0086] Therefore, the embodiment of the present application introduces a logic for judging the vehicle weight of the whole vehicle, formulates different logics according to different load ranges, and tries to use electric motor braking as much as possible on the premise of ensuring safety. When the load is small, if the required deceleration is small, no backup pressure is applied; if the required deceleration is large, backup pressure is applied; when the load is large, backup pressure is directly applied, and a certain air pressure is reserved in advance in the brake air chamber, which can overcome the opening pressure of the brake, but there is no actual braking force output. When the electric motor braking is insufficient and the air brake needs to be intervened, the response time can be shortened to make the air brake intervene as soon as possible to ensure vehicle safety.

[0087] Further, if the maximum achievable deceleration is greater than or equal to the target required deceleration, it indicates that the motor of the current vehicle has the ability to fully execute the target required deceleration. At this time, a first initial motor braking deceleration is allocated to the current vehicle, and the target required deceleration is used as the first initial motor braking deceleration of the current vehicle, that is, a1(1) = a, where a1(1) is the first initial motor braking deceleration and a is the target required deceleration.

[0088] Further, the vehicle speed of the current vehicle is obtained through the vehicle instrument or the vehicle speed sensor, and it is determined whether the vehicle speed of the current vehicle is greater than a third preset threshold (such as 10 km / h). If the vehicle speed of the current vehicle is greater than the third preset threshold, the wheel slip ratio of the current vehicle is calculated according to the following formula:

[0089]

[0090] where S is the wheel slip ratio, u is the vehicle speed, and u w is the wheel speed.

[0091] It can be understood that if the wheel is in pure rolling, uw = u and s = 0; when the wheel is locked and in pure sliding, uw = 0 and s = 100%; when the wheel is rolling and sliding, u > uw and 0 < s < 100%. The larger the wheel slip ratio, the greater the proportion of the sliding component in the movement of the wheel, the worse the vehicle stability, and the less safe. To ensure vehicle safety and avoid wheel locking, when the wheel has a tendency to lock, that is, when the wheel slip ratio is greater than a fourth preset threshold, the allocated motor braking deceleration is reduced, a1(n + 1) = a1(n) * T4 / S(n), and the step of allocating the first initial motor braking deceleration is re-executed. Where a1(n + 1) is the deceleration allocated to the motor braking in the (n + 1)-th cycle; a1(n) is the deceleration allocated to the motor braking in the n-th cycle; T4 is the fourth preset threshold; and S(n) is the slip ratio in the n-th cycle.

[0092] Thus, the embodiment of the present application introduces a logic for judging the wheel slip ratio. The tendency of the wheel to lock can be judged by the magnitude and duration of the slip ratio. When there is a tendency to lock, a preset algorithm is used to gradually reduce the braking force and reduce the wheel slip ratio to ensure vehicle safety.

[0093] Further, if the wheel slip ratio is less than or equal to the fourth preset threshold, the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold is obtained through a timer. If the duration is greater than or equal to a fifth preset threshold, the actual execution deceleration of the current vehicle is calculated in real time according to the vehicle speed and time, and the calculation formula is where Δv is the vehicle speed difference within Δt time.

[0094] Further, calculate the error value between the actual execution deceleration a2 of the current vehicle and the target required deceleration a. The calculation formula for the error value is After calculating the error value between the actual execution deceleration a2 of the current vehicle and the target required deceleration a, determine whether the error value is greater than the sixth preset threshold. If the error value is less than or equal to the sixth preset threshold, keep the current motor braking deceleration unchanged. If the error value is greater than the sixth preset threshold, further determine whether the actual execution deceleration a2 of the current vehicle is greater than the target required deceleration a. If the actual execution deceleration a2 of the current vehicle is greater than the target required deceleration a, it means that the current actual execution deceleration is too large. To ensure the accuracy of the actual execution deceleration, closed-loop control is required to reduce the allocated motor braking deceleration, that is, a1(n + 1) = a1(n) - (a2(n) - a) / 2, and re-execute the step of allocating the first initial motor braking deceleration. Wherein, a1(n + 1) is the deceleration allocated to the motor braking in the (n + 1)-th cycle; a1(n) is the deceleration allocated to the motor braking in the n-th cycle; a2(n) is the actual execution deceleration in the n-th cycle; a is the target required deceleration.

[0095] In addition, if the actual execution deceleration a2 of the current vehicle is less than or equal to the target required deceleration a, it means that the current actual execution deceleration is too small. To ensure the accuracy of the actual execution deceleration, closed-loop control is required to increase the allocated motor braking deceleration, that is, a1(n + 1) = a1(n) + (a - a2(n)) / 2, and re-execute the step of allocating the first initial motor braking deceleration. Wherein, a1(n + 1) is the deceleration allocated to the motor braking in the (n + 1)-th cycle; a1(n) is the deceleration allocated to the motor braking in the n-th cycle; a2(n) is the actual execution deceleration in the n-th cycle; a is the target required deceleration.

[0096] Thus, by introducing a closed-loop control logic, the embodiment of the present application monitors the actual execution braking deceleration in real time, and determines whether the requirements are met according to the preset threshold of the error between the actual execution deceleration and the required deceleration. When the requirements are not met, the preset algorithm is used to gradually increase or decrease the braking force to finally meet the requirements of the error threshold and ensure the accuracy of the execution deceleration.

[0097] Further, in some embodiments, after determining that the vehicle weight of the current vehicle is less than or equal to the first preset threshold and the target required deceleration is less than or equal to the second preset threshold, the following steps are further included: If the maximum executable deceleration is less than the target required deceleration, allocate a second initial electric motor braking deceleration to the current vehicle and allocate an initial pneumatic braking deceleration to the current vehicle; If the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle. If the wheel slip ratio is greater than the fourth preset threshold, calculate the deceleration reduced for the pneumatic braking to obtain a reduced first pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the first pneumatic braking deceleration; If the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold. If the duration is greater than or equal to the fifth preset threshold, calculate the actual executed deceleration of the current vehicle; If the error value between the actual executed deceleration and the target required deceleration is greater than the sixth preset threshold, when the actual executed deceleration is greater than the target required deceleration, calculate the deceleration reduced for the pneumatic braking to obtain a reduced second pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the second pneumatic braking deceleration. Otherwise, calculate the increased deceleration for the pneumatic braking and update the initial pneumatic braking deceleration based on the increased third pneumatic braking deceleration.

[0098] Specifically, if the maximum executable deceleration is less than the target required deceleration, it indicates that the motor is not capable of fully executing the required deceleration. Allocate a second initial electric motor braking deceleration to the current vehicle, take the maximum executable deceleration a0 as the second initial electric motor braking deceleration, and allocate an initial pneumatic braking deceleration to the current vehicle, where the initial pneumatic braking deceleration a3(1)=a - a0.

[0099] Further, obtain the vehicle speed of the current vehicle through the vehicle instrument or the vehicle speed sensor, and determine whether the vehicle speed of the current vehicle is greater than the third preset threshold (such as 10 km / h). If the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle according to the following formula:

[0100]

[0101] where S is the wheel slip ratio, u is the vehicle speed, and u w is the wheel speed.

[0102] It is understandable that when the wheel is in pure rolling, uw = u and s = 0; when the wheel is locked and in pure sliding, uw = 0 and s = 100%; when the wheel is rolling and sliding, u > uw and 0 < s < 100%. The larger the wheel slip ratio, the greater the proportion of the sliding component in the movement of the wheel, the worse the vehicle stability, and the less safe. To ensure vehicle safety and avoid wheel locking, when the wheel has a tendency to lock, that is, when the wheel slip ratio is greater than the fourth preset threshold, the distributed air pressure braking deceleration is reduced, a3(n + 1) = a3(n) * T4 / S(n), and the step of allocating the initial air pressure braking deceleration for the current vehicle is executed again. Wherein, a3(n + 1) is the deceleration allocated to the air pressure braking in the (n + 1)-th cycle; a3(n) is the deceleration allocated to the air pressure braking in the n-th cycle; T4 is the fourth preset threshold; S(n) is the slip ratio in the n-th cycle.

[0103] Furthermore, if the wheel slip ratio is less than or equal to the fourth preset threshold, the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold is obtained through a timer. If the duration is greater than or equal to the fifth preset threshold, the actual execution deceleration of the current vehicle is calculated in real time based on the vehicle speed and time, and the calculation formula is Wherein, Δv is the vehicle speed difference within Δt time.

[0104] Furthermore, the error value between the actual execution deceleration a2 of the current vehicle and the target required deceleration a is calculated. The calculation formula for the error value is After calculating the error value between the actual execution deceleration a2 of the current vehicle and the target required deceleration a, it is determined whether the error value is greater than the sixth preset threshold. If the error value is less than or equal to the sixth preset threshold, the current air pressure braking deceleration remains unchanged. If the error value is greater than the sixth preset threshold, it is further determined whether the actual execution deceleration a2 of the current vehicle is greater than the target required deceleration a. If the actual execution deceleration a2 of the current vehicle is greater than the target required deceleration a, it means that the current actual execution deceleration is too large. To ensure the accuracy of the actual execution deceleration, closed-loop control is required to reduce the distributed air pressure braking deceleration, that is, a3(n + 1) = a3(n) - (a2(n) - a) / 2, and the step of allocating the initial air pressure braking deceleration for the current vehicle is executed again. Wherein, a3(n + 1) is the deceleration allocated to the air pressure braking in the (n + 1)-th cycle; a3(n) is the deceleration allocated to the air pressure braking in the n-th cycle; a2(n) is the actual execution deceleration in the n-th cycle; a is the target required deceleration.

[0105] In addition, if the actual deceleration a2 of the current vehicle is less than or equal to the target required deceleration a, it indicates that the current actual deceleration is too small. To ensure the accuracy of the actual deceleration, closed-loop control is required to increase the distributed air pressure braking deceleration, that is, a3(n + 1) = a3(n) + (a - a2(n)) / 2, and the step of allocating the initial air pressure braking deceleration for the current vehicle is executed again. Among them, a3(n + 1) is the deceleration allocated to the air pressure braking in the (n + 1)-th cycle; a3(n) is the deceleration allocated to the air pressure braking in the n-th cycle; a2(n) is the actual deceleration in the n-th cycle; a is the target required deceleration.

[0106] To facilitate those skilled in the art to more clearly and intuitively understand the process of air-electric composite braking deceleration distribution of the vehicle in the embodiments of the present application, the following is combined with Figure 4 for detailed description.

[0107] As Figure 4 shown, the process of air-electric composite braking deceleration distribution of the vehicle includes the following steps:

[0108] S401, Start.

[0109] S402, Obtain the depth of the brake pedal.

[0110] S403, Determine the required deceleration a.

[0111] S404, Judge whether the vehicle weight of the whole vehicle is less than or equal to the threshold T1. If so, execute S405; otherwise, execute S406.

[0112] S405, Judge whether the required deceleration a is less than or equal to the threshold T2. If so, execute S407; otherwise, execute S406.

[0113] S406, Air pressure braking standby pressure p0.

[0114] S407, Judge whether the motor capacity a0 is greater than or equal to a. If so, execute S408; otherwise, execute S417.

[0115] S408, Allocate the motor braking deceleration a1.

[0116] S409, Judge whether the vehicle speed V is less than or equal to the threshold T3. If so, execute S411; otherwise, execute S410.

[0117] S410, Judge whether the wheel slip ratio S is less than or equal to the threshold T4 and the duration t is greater than or equal to the threshold T5. If so, execute S411; otherwise, execute S412.

[0118] S411. Calculate the actual deceleration a2.

[0119] S412. Reduce the allocated motor braking deceleration, a1(n + 1) = a1(n) * T4 / S(n).

[0120] S413. Determine whether |a2 - a| / max(a, a2) is less than or equal to the threshold T6. If so, execute S426; otherwise, execute S414.

[0121] S414. Determine whether the actual deceleration a2 is greater than a. If so, execute S415; otherwise, execute S416.

[0122] S415. Reduce the allocated motor braking deceleration, a1(n + 1) = a1(n) - (a2(n) - a) / 2.

[0123] S416. Increase the allocated motor braking deceleration, a1(n + 1) = a1(n) + (a - a2(n)) / 2.

[0124] S417. Allocate the motor braking deceleration a0 and the pneumatic braking deceleration a3.

[0125] S418. Determine whether the vehicle speed V is less than or equal to the threshold T3. If so, execute S420; otherwise, execute S419.

[0126] S419. Determine whether the wheel slip ratio S is less than or equal to the threshold T4 and the duration t is greater than or equal to the threshold T5. If so, execute S420; otherwise, execute S421.

[0127] S420. Calculate the actual deceleration a2.

[0128] S421. Reduce the allocated pneumatic braking deceleration, a3(n + 1) = a3(n) * T4 / S(n).

[0129] S422. Determine whether |a2 - a| / max(a, a2) is less than or equal to the threshold T6. If so, execute S426; otherwise, execute S423.

[0130] S423. Determine whether the actual deceleration a2 is greater than a. If so, execute S424; otherwise, execute S425.

[0131] S424. Reduce the allocated pneumatic braking deceleration, a3(n + 1) = a3(n) - (a2(n) - a) / 2.

[0132] S425. Increase the allocated pneumatic braking deceleration, a3(n + 1) = a3(n) + (a - a2(n)) / 2.

[0133] S426, end.

[0134] Thus, after the function of the electro-pneumatic composite braking system is activated in the embodiments of the present application, the distribution ratio of the electric braking and the pneumatic braking is uniformly distributed after comprehensive judgment based on information such as the pedal depth, vehicle weight, and motor capacity, and the execution of the actual vehicle deceleration is monitored for closed-loop control and real-time optimization of the control logic, so as to use as much electric braking as possible, increase energy recovery, and use less pneumatic braking, thereby reducing the wear of the friction plates.

[0135] Further, in some embodiments, before obtaining the braking pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle, it further includes: obtaining the status of the electro-pneumatic composite braking management system of the current vehicle and the status of the enable switch; if the status of the electro-pneumatic composite braking management system is a fault-free state, and the status of the enable switch is an on state, and the current vehicle meets the preset preconditions for function activation, and the current vehicle is not in a preset emergency condition, then controlling the current vehicle to activate the electro-pneumatic composite braking function; wherein, when the motor, transmission, wheel speed sensor, and braking pedal sensor of the current vehicle are not in a fault state, it is determined that the status of the electro-pneumatic composite braking management system of the current vehicle is a fault-free state.

[0136] Optionally, the preset preconditions for function activation are that the vehicle speed of the current vehicle is greater than or equal to the seventh preset threshold, and the driveline status is a combined state, and there is no electric braking torque, and the throttle pedal status is an unpressed state, and the braking pedal status is a pressed state. The preset emergency condition is that the braking pedal opening of the current vehicle is greater than or equal to the eighth preset threshold, and the speed at which the braking pedal is pressed is greater than or equal to the ninth preset threshold.

[0137] Among them, the seventh preset threshold can be 3 km / h, the eighth preset threshold can be 45%, and the ninth preset threshold can be 540% / s, which are not specifically limited herein.

[0138] Specifically, the embodiments of the present application can detect relevant messages of the motor and the transmission to determine whether there is a fault in the motor or the transmission, and can also actually detect whether there are faults such as wiring harnesses in the wheel speed sensor and the braking pedal sensor. If any device has a fault, the fault information is sent to the instrument through the CAN message, and the yellow fault light of the instrument is always on. At this time, the function of the electro-pneumatic composite braking system is limited, and pure pneumatic braking is used during braking. In addition, if the motor, transmission, wheel speed sensor, and braking pedal sensor of the current vehicle are not in a fault state, it is determined that the status of the electro-pneumatic composite braking management system of the current vehicle is a fault-free state.

[0139] Further, an enable switch is introduced in the embodiments of the present application. In special working conditions, such as on low-adhesion roads, using electric motor braking is likely to cause wheel lock-up and affect vehicle stability. The driver can turn off the enable switch so that electric motor braking is not invoked during braking, ensuring vehicle safety under special working conditions. Specifically, on the premise that the air-electric composite braking management system is fault-free, the state of the enable switch is detected. If the switch state is enabled, the enable state information is sent to the instrument via a CAN message, and the green indicator light on the instrument stays on constantly.

[0140] Further, on the premise of function enabling, it is detected whether the current vehicle meets the preset preconditions for function activation. If the speed of the current vehicle is greater than or equal to the seventh preset threshold, and the driveline state is in the engaged state, and there is no electric motor braking torque, and the accelerator pedal state is in the non-pressed state, and the brake pedal state is in the pressed state, it is determined that the current vehicle meets the preset preconditions for function activation. For example, if the speed of the current vehicle ≥ 3 km / h && the driveline is engaged && there is no electric motor braking torque && the accelerator pedal is released && the brake pedal is pressed, it is determined that the current vehicle meets the preset preconditions for function activation.

[0141] Further, the embodiments of the present application introduce a logic for judging emergency braking working conditions, which can avoid the reduction of vehicle stability caused by the intervention of electric motor braking during emergency braking and ensure vehicle safety. Specifically, on the premise of meeting the preset preconditions for function activation, it is detected whether the current vehicle meets the preset emergency working condition. When the driver presses the brake pedal, the system collects the opening and speed of the driver pressing the brake pedal through the brake pedal sensor. If the opening of the brake pedal of the current vehicle is greater than or equal to the eighth preset threshold, and the speed at which the brake pedal is pressed is greater than or equal to the ninth preset threshold, it is determined that the current vehicle meets the preset emergency working condition. For example, when the brake pedal opening ≥ 45% && the speed at which the brake pedal is pressed ≥ 540% / s, it is judged as a preset emergency working condition, and other situations are judged as non-preset emergency working conditions. If the current vehicle is not in the preset emergency working condition, the air-electric composite braking function of the current vehicle is controlled to be activated, that is, the activation state information is sent to the instrument via a CAN message, the green indicator light on the instrument flashes, and a torque request is sent to the motor via a CAN message. The motor performs electric motor braking, and at the same time, an air pressure request is sent to the front and rear axle modules via a private CAN message to supply air pressure to the brake, and the brake performs air pressure braking.

[0142] Further, in some embodiments, after controlling the current vehicle to activate the gas-electric composite braking function, the method further includes: continuously monitoring the ignition switch state, enable switch state, vehicle speed of the current vehicle, driveline state, wheel state, brake pedal state, accelerator pedal state, and gas-electric composite braking management system state of the current vehicle; if the ignition switch state of the current vehicle is in the off state, or the enable switch state is in the off state, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the driveline state is in the disconnected state, or the wheel state is in the locked state, or the brake pedal state is in the unpressed state, or the accelerator pedal state is in the pressed state, or the gas-electric composite braking management system state is in the fault state, then control the current vehicle to exit the gas-electric composite braking function.

[0143] Specifically, on the premise that the gas-electric composite braking function is activated, continuously detect whether the current vehicle meets the function exit conditions. If the ignition switch state of the current vehicle is in the off state, or the enable switch state is in the off state, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the driveline state is in the disconnected state, or the wheel state is in the locked state, or the brake pedal state is in the unpressed state, or the accelerator pedal state is in the pressed state, or the gas-electric composite braking management system state is in the fault state, then control the current vehicle to exit the gas-electric composite braking function.

[0144] For example, if the current vehicle meets the conditions of turning off the key power || turning off the enable switch || vehicle speed < 3 km / h || driveline disconnected || wheels tend to lock || releasing the brake pedal || pressing the accelerator pedal || system failure, etc., it is determined that the current vehicle meets the gas-electric composite braking function exit conditions, and the activation status information is sent to the instrument through the CAN message, and the green indicator light on the instrument is always on or off; and stop sending the torque request message, the motor exits the electric braking, and stop sending the air pressure request message, the front and rear axle modules release the brake air pressure, and the brake exits the air pressure braking, so as to realize that the current vehicle exits the gas-electric composite braking function.

[0145] To facilitate those skilled in the art to more clearly and intuitively understand the gas-electric composite braking method of the vehicle in the embodiments of the present application, the following will be combined with Figure 5 for detailed description.

[0146] As Figure 5 shown, the gas-electric composite braking method of the vehicle includes the following steps:

[0147] S501, Start.

[0148] S502, IG ON.

[0149] S503, Determine whether the system is fault-free. If so, execute S504; otherwise, execute S505.

[0150] S504, Determine whether the switch is enabled. If so, execute S506; otherwise, execute S507.

[0151] S505, Functional failure, the yellow indicator light of the instrument is always on, and pure air pressure braking is applied during braking.

[0152] S506, Function enabled, the green indicator light of the instrument is always on.

[0153] S507, Pure air pressure braking is applied during braking.

[0154] S508, Determine whether the activation precondition is met. If so, execute S509; otherwise, execute S513.

[0155] S509, Determine whether it is an emergency condition. If so, execute S513; otherwise, execute S510.

[0156] S510, Function activation, the controller sends a torque request command to the motor and executes electric braking. At the same time, air pressure is supplied to the brake to execute air pressure braking. The green indicator light of the instrument flashes.

[0157] S511, Determine whether the exit condition is met. If so, execute S512; otherwise, execute S510.

[0158] S512, Function activation exit, the controller stops sending the torque request command to the motor and the electric braking exits; at the same time, the air pressure of the brake is released and the air pressure braking exits. The green indicator light of the instrument is always on or off.

[0159] S513, End.

[0160] Thus, in the embodiment of the present application, by introducing the logic for judging the motor ability, when the motor ability is sufficient, the air pressure braking is not intervened and the electric braking is fully used, which can maximize the utilization rate of the electric braking; when the motor ability is insufficient, the air pressure braking is supplemented on the premise that the full use of the electric braking ability is still insufficient; the electric braking can be maximally used, reducing the wear of the friction plate and improving the energy recovery efficiency at the same time. In addition, in the embodiment of the present application, by introducing the instrument indicator light, when the enable switch is enabled, the green indicator light is always on, reminding the driver that the air-electric composite braking system has been enabled and can be used normally; when the system fails, the yellow indicator light is always on, reminding the driver that the system has failed and the function of the air-electric composite braking system is unavailable, please repair and check in time; when the system is working, the green indicator light flashes, reminding the driver that the system is working, improving the user experience.

[0161] The electro-pneumatic composite braking method for a vehicle according to an embodiment of the present application determines the electric braking distribution ratio and the pneumatic braking distribution ratio of the current vehicle based on the braking pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; and performs electro-pneumatic composite braking on the current vehicle based on the electric braking distribution ratio and the pneumatic braking distribution ratio of the current vehicle. Thereby, problems such as the existing braking method being unfavorable for driving safety and the decline of braking efficiency are solved. On the premise of ensuring driving safety, by invoking the motor to intervene for as much auxiliary braking as possible, the use of wheel-end brakes is reduced, the wear of friction plates is reduced, and the energy recovery efficiency is improved.

[0162] Next, a description is given of the electro-pneumatic composite braking device for a vehicle according to an embodiment of the present application with reference to the accompanying drawings.

[0163] Figure 6 It is a block diagram of the electro-pneumatic composite braking device for a vehicle according to an embodiment of the present application.

[0164] As Figure 6 shown, the electro-pneumatic composite braking device 10 of the vehicle includes: an acquisition module 100, a determination module 200, and an electro-pneumatic composite braking module 300.

[0165] Among them, the acquisition module 100 is configured to acquire the braking pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; the determination module 200 is configured to determine the electric braking distribution ratio and the pneumatic braking distribution ratio of the current vehicle based on the braking pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; the electro-pneumatic composite braking module 300 is configured to perform electro-pneumatic composite braking on the current vehicle based on the electric braking distribution ratio and the pneumatic braking distribution ratio of the current vehicle.

[0166] Further, in some embodiments, the determining module 200 is configured to: determine a target required deceleration according to the brake pedal opening, and determine the maximum achievable deceleration of the current vehicle according to the motor capacity; if the vehicle weight of the current vehicle is less than or equal to a first preset threshold and the target required deceleration is less than or equal to a second preset threshold, then when the maximum achievable deceleration is greater than or equal to the target required deceleration, use the target required deceleration as the first initial electric motor braking deceleration of the current vehicle; determine whether the vehicle speed of the current vehicle is greater than a third preset threshold, if the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle, if the wheel slip ratio is greater than a fourth preset threshold, calculate the deceleration reduced for electric motor braking to obtain a reduced first electric motor braking deceleration, and update the first initial electric motor braking deceleration based on the first electric motor braking deceleration; if the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold, if the duration is greater than or equal to a fifth preset threshold, calculate the actual executed deceleration of the current vehicle; if the actual executed deceleration is greater than the target required deceleration, when the error value between the actual executed deceleration and the target required deceleration is greater than a sixth preset threshold, calculate the deceleration reduced for electric motor braking to obtain a reduced second electric motor braking deceleration, and update the first initial electric motor braking deceleration based on the second electric motor braking deceleration, otherwise, calculate the deceleration increased for electric motor braking and update the first initial electric motor braking deceleration based on the increased third electric motor braking deceleration.

[0167] Further, in some embodiments, after determining that the vehicle weight of the current vehicle is less than or equal to the first preset threshold and the target required deceleration is less than or equal to the second preset threshold, the determining module 200 is further configured to: if the maximum executable deceleration is less than the target required deceleration, allocate a second initial electric motor braking deceleration to the current vehicle and allocate an initial pneumatic braking deceleration to the current vehicle; if the vehicle speed of the current vehicle is greater than the third preset threshold, calculate the wheel slip ratio of the current vehicle, and if the wheel slip ratio is greater than the fourth preset threshold, calculate the deceleration reduced to the pneumatic braking to obtain a reduced first pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the first pneumatic braking deceleration; if the wheel slip ratio is less than or equal to the fourth preset threshold, obtain the duration during which the wheel slip ratio is less than or equal to the fourth preset threshold, and if the duration is greater than or equal to the fifth preset threshold, calculate the actual executed deceleration of the current vehicle; if the error value between the actual executed deceleration and the target required deceleration is greater than the sixth preset threshold, when the actual executed deceleration is greater than the target required deceleration, calculate the deceleration reduced to the pneumatic braking to obtain a reduced second pneumatic braking deceleration, and update the initial pneumatic braking deceleration based on the second pneumatic braking deceleration, otherwise, calculate the increased deceleration allocated to the pneumatic braking and update the initial pneumatic braking deceleration based on the increased third pneumatic braking deceleration.

[0168] Further, in some embodiments, before obtaining the brake pedal opening degree of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle, the obtaining module 100 is further configured to: obtain the state of the pneumatic-electric composite braking management system and the enabling switch state of the current vehicle; if the state of the pneumatic-electric composite braking management system is a fault-free state, the enabling switch state is an on state, the current vehicle meets the preset preconditions for function activation, and the current vehicle is not in a preset emergency condition, control the current vehicle to activate the pneumatic-electric composite braking function; wherein, when the motor, transmission, wheel speed sensor, and brake pedal sensor of the current vehicle are all not in a fault state, it is determined that the state of the pneumatic-electric composite braking management system of the current vehicle is a fault-free state.

[0169] Further, in some embodiments, the preset preconditions for function activation are that the vehicle speed of the current vehicle is greater than or equal to the seventh preset threshold, the driveline state is a combined state, there is no electric motor braking torque, the throttle pedal state is an unpressed state, and the brake pedal state is a pressed state.

[0170] Further, in some embodiments, the preset emergency condition is that the brake pedal opening degree of the current vehicle is greater than or equal to the eighth preset threshold and the speed at which the brake pedal is pressed is greater than or equal to the ninth preset threshold.

[0171] Further, in some embodiments, after controlling the current vehicle to activate the gas-electric composite braking function, the gas-electric composite braking module 300 is further configured to continuously monitor the ignition switch state, enable switch state, vehicle speed, driveline state, wheel state, brake pedal state, accelerator pedal state, and gas-electric composite braking management system state of the current vehicle; if the ignition switch state of the current vehicle is in the off state, or the enable switch state is in the off state, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the driveline state is in the disconnected state, or the wheel state is in the locked state, or the brake pedal state is in the unpressed state, or the accelerator pedal state is in the pressed state, or the gas-electric composite braking management system state is in the fault state, then control the current vehicle to exit the gas-electric composite braking function.

[0172] It should be noted that the foregoing explanation of the embodiments of the gas-electric composite braking method for vehicles also applies to the gas-electric composite braking device of the vehicle in this embodiment, and will not be elaborated here.

[0173] The gas-electric composite braking device of the vehicle according to the embodiment of the present application determines the electric braking distribution ratio and the air pressure braking distribution ratio of the current vehicle according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle, and the motor capacity of the current vehicle; performs gas-electric composite braking on the current vehicle based on the electric braking distribution ratio and the air pressure braking distribution ratio of the current vehicle. Thereby, the problems that the existing braking method is not conducive to driving safety and the braking efficiency decreases are solved. On the premise of ensuring driving safety, by calling the motor to intervene for as much auxiliary braking as possible, the use of wheel-end brakes is reduced, the wear of friction plates is reduced, and the energy recovery efficiency is improved.

[0174] Figure 7 The structural schematic diagram of the vehicle provided by the embodiment of the present application. The vehicle may include:

[0175] A memory 701, a processor 702, and a computer program stored on the memory 701 and executable on the processor 702.

[0176] When the processor 702 executes the program, it implements the gas-electric composite braking method for the vehicle provided in the foregoing embodiment.

[0177] Further, the vehicle further includes:

[0178] A communication interface 703 for communication between the memory 701 and the processor 702.

[0179] The memory 701 is used to store a computer program executable on the processor 702.

[0180] The memory 701 may include high-speed RAM memory and may also include non-volatile memory, such as at least one disk memory.

[0181] If the memory 701, the processor 702, and the communication interface 703 are implemented independently, the communication interface 703, the memory 701, and the processor 702 can be interconnected through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity of representation, Figure 7 only a thick line is used to represent it in the figure, but it does not mean that there is only one bus or one type of bus.

[0182] Optionally, in a specific implementation, if the memory 701, the processor 702, and the communication interface 703 are integrated on a single chip, the memory 701, the processor 702, and the communication interface 703 can communicate with each other through an internal interface.

[0183] The processor 702 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0184] The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the gas-electric composite braking method of the vehicle as described above is implemented.

[0185] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0186] In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0187] Any process or method description shown in a flowchart or described in other ways herein can be understood as representing a module, segment, or portion of code including one or more N executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of this application includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in a reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of this application pertain.

[0188] The logic and / or steps represented in the flowchart or otherwise described herein can, for example, be considered as a definitional sequence of executable instructions for implementing logical functions, which can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. As used in this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of the computer-readable medium include the following: an electrical connection part (electronic device) having one or N wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0189] It should be understood that various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0190] Those of ordinary skill in the art of the present technology can understand that all or part of the steps carried by the method of implementing the above embodiments can be completed by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and when the program is executed, it includes one or a combination of the steps of the method embodiments.

[0191] In addition, each functional unit in various embodiments of the present application may be integrated into one processing module, may exist physically alone for each unit, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0192] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A pneumatic-electric hybrid braking method for a vehicle, characterized in that: The following steps are involved: Acquiring a brake pedal opening of a current vehicle, a vehicle weight of the current vehicle, and a motor capacity of the current vehicle; Determining a motor braking distribution ratio of the current vehicle and a pneumatic braking distribution ratio of the current vehicle according to a brake pedal opening of the current vehicle, a vehicle weight of the current vehicle, and a motor capacity of the current vehicle; The current vehicle is subjected to pneumatic-electrical composite braking based on the motor braking allocation ratio of the current vehicle and the pneumatic braking allocation ratio of the current vehicle.

2. The method according to claim 1, characterized in that The determining the motor braking distribution ratio of the current vehicle and the air pressure braking distribution ratio of the current vehicle according to the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle and the motor capacity of the current vehicle includes: determining a target required deceleration according to the brake pedal opening, and determining a maximum executable deceleration of the current vehicle according to the motor capacity; If the vehicle weight of the current vehicle is less than or equal to a first preset threshold, and the target required deceleration is less than or equal to a second preset threshold, then when the maximum executable deceleration is greater than or equal to the target required deceleration, the target required deceleration is used as the first initial motor braking deceleration of the current vehicle; Determine whether the speed of the current vehicle is greater than a third preset threshold value, if the speed of the current vehicle is greater than the third preset threshold value, calculate the wheel slip rate of the current vehicle, if the wheel slip rate is greater than a fourth preset threshold value, calculate and reduce the deceleration allocated to the motor braking to obtain a reduced first motor braking deceleration, and update the first initial motor braking deceleration based on the first motor braking deceleration; If the wheel slip rate is less than or equal to the fourth preset threshold, then obtaining a duration during which the wheel slip rate is less than or equal to the fourth preset threshold; if the duration is greater than or equal to the fifth preset threshold, then calculating an actual deceleration of the current vehicle; If the actual execution deceleration is greater than the target required deceleration, then when the error value between the actual execution deceleration and the target required deceleration is greater than a sixth preset threshold, the deceleration allocated to the motor braking is reduced by calculation to obtain a reduced second motor braking deceleration, and the first initial motor braking deceleration is updated based on the second motor braking deceleration; otherwise, the deceleration allocated to the motor braking is increased by calculation, and the first initial motor braking deceleration is updated based on the increased third motor braking deceleration.

3. The method according to claim 2, characterized in that After determining that the vehicle weight of the current vehicle is less than or equal to a first preset threshold, and the target required deceleration is less than or equal to a second preset threshold, the method further includes: If the maximum executable deceleration is less than the target required deceleration, allocating a second initial motor braking deceleration to the current vehicle and allocating an initial pneumatic braking deceleration to the current vehicle; If the vehicle speed of the current vehicle is greater than the third preset threshold, the wheel slip rate of the current vehicle is calculated; if the wheel slip rate is greater than a fourth preset threshold, the deceleration allocated to the air brake is reduced by calculating to obtain a reduced first air brake deceleration, and the initial air brake deceleration is updated based on the first air brake deceleration; If the wheel slip rate is less than or equal to the fourth preset threshold, then obtaining a duration during which the wheel slip rate is less than or equal to the fourth preset threshold; if the duration is greater than or equal to the fifth preset threshold, then calculating an actual deceleration of the current vehicle; If the error value between the actual execution deceleration and the target required deceleration is greater than a sixth preset threshold value, then when the actual execution deceleration is greater than the target required deceleration, the deceleration allocated to the pneumatic brake is reduced by calculation to obtain a reduced second pneumatic brake deceleration, and the initial pneumatic brake deceleration is updated based on the second pneumatic brake deceleration; otherwise, the deceleration allocated to the pneumatic brake is increased by calculation, and the initial pneumatic brake deceleration is updated based on the increased third pneumatic brake deceleration.

4. The method according to claim 1, characterized in that: Before obtaining the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle and the motor capacity of the current vehicle, the method further includes: Get the status of the gas-electric hybrid brake management system and the enabling switch status of the current vehicle; If the state of the gas-electric hybrid brake management system is a non-fault state, and the state of the enabling switch is an on state, and the current vehicle meets the preset function activation preconditions, and the current vehicle is not in a preset emergency condition, then the current vehicle is controlled to activate the gas-electric hybrid brake function; Wherein, when the motor, gearbox, wheel speed sensor and brake pedal sensor of the current vehicle are not in a fault state, it is determined that the state of the gas-electric hybrid brake management system of the current vehicle is the non-fault state.

5. The method according to claim 4, characterized in that The precondition for activating the preset function is that the current vehicle speed is greater than or equal to the seventh preset threshold, the transmission system state is in the engaged state, there is no motor braking torque, the accelerator pedal state is in the unpressed state, and the brake pedal state is in the pressed state.

6. The method according to claim 4, characterized in that The preset emergency operating condition is that the brake pedal opening of the current vehicle is greater than or equal to an eighth preset threshold, and the speed at which the brake pedal is depressed is greater than or equal to a ninth preset threshold.

7. The method according to claim 4, characterized in that After controlling the current vehicle to activate the gas-electric composite brake function, the method further includes: Continuously monitoring the ignition switch state, the enable switch state, the vehicle speed, the powertrain state, the wheel state, the brake pedal state, the accelerator pedal state and the gas-electric hybrid brake management system state of the current vehicle; If the ignition switch state of the current vehicle is off, or the enable switch state is off, or the vehicle speed of the current vehicle is less than the seventh preset threshold, or the transmission system state is disconnected, or the wheel state is locked, or the brake pedal state is not pressed, or the accelerator pedal state is pressed, or the gas-electric hybrid brake management system state is a fault state, then the current vehicle is controlled to exit the gas-electric hybrid brake function.

8. A pneumatic-electric composite brake device for a vehicle, characterized in that: include: An acquisition module, used to acquire the brake pedal opening of the current vehicle, the vehicle weight of the current vehicle and the motor capacity of the current vehicle; A determination module, configured to determine a motor braking allocation ratio of the current vehicle and a pneumatic braking allocation ratio of the current vehicle according to a brake pedal opening of the current vehicle, a vehicle weight of the current vehicle, and a motor capacity of the current vehicle; The pneumatic-electric composite braking module is used to perform pneumatic-electric composite braking on the current vehicle based on the motor braking allocation ratio of the current vehicle and the pneumatic braking allocation ratio of the current vehicle.

9. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the gas-electric hybrid braking method for a vehicle as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the gas-electric hybrid braking method for a vehicle as claimed in any one of claims 1 to 7.

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