Braking force output methods, devices, vehicles and storage media

Abstract

This application discloses a braking force output method, device, vehicle, and storage medium, belonging to the field of vehicle technology. It includes: when a first vehicle is brought to a stop and the brake pedal is released, controlling the braking system of the first vehicle to output a reference braking force and determining a first braking force based on the vehicle's mass, target torque, and the slope of the vehicle's location; determining a braking force safety factor based on environmental information of the vehicle's location, the braking force safety factor being used to improve the parking safety of the first vehicle; and reducing the braking force output by the braking system while keeping the first vehicle stationary, based on the reference braking force, the first braking force, the slope, and the braking force safety factor. Thus, by reducing the braking force output by the braking system, the vehicle can use less electrical energy to park, thereby achieving the effect of saving energy while ensuring parking safety.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a braking force output method, device, vehicle, and storage medium. Background Technology

[0002] With the development of technology, vehicles are incorporating more and more functions, providing great convenience for drivers. For example, the automatic parking function allows the user to apply braking force after pressing and releasing the brake pedal, thus achieving automatic parking.

[0003] In related technologies, after the driver presses the brake pedal, the vehicle will obtain the maximum braking force when the driver presses the brake pedal, and then apply the maximum braking force to the vehicle's wheels to ensure that the vehicle can automatically stop.

[0004] Normally, braking force is obtained by the torque output of the servo motor in the vehicle's brake-by-wire system. Therefore, in the aforementioned method of controlling vehicle parking, the motor outputs a large torque, which wastes the vehicle's electrical energy and results in the underutilization of the vehicle's electrical resources. Summary of the Invention

[0005] This application provides a braking force output method, device, vehicle, and storage medium, which can reduce the braking force output by the braking system, thereby saving vehicle electrical energy while ensuring parking safety. The technical solution is as follows:

[0006] In a first aspect, a method for outputting braking force is provided, the method comprising:

[0007] When the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, the braking system of the first vehicle is controlled to output a reference braking force and a first braking force of the first vehicle is determined based on the vehicle mass, target torque and slope of the first vehicle's location. The reference braking force is the maximum braking force output by the braking system during the braking process of the first vehicle being brought to a stop, the target torque is the torque output by the first vehicle when it is idling, and the first braking force is the theoretical braking force required when the first vehicle is parked at its current location.

[0008] Based on the environmental information of the location of the first vehicle, the braking force safety factor of the first vehicle is determined, and the braking force safety factor is used to improve the parking safety of the first vehicle.

[0009] Based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced while keeping the first vehicle stationary.

[0010] In this application, when the first vehicle is brought to a stop and the brake pedal is released, the braking system of the first vehicle is controlled to output a reference braking force. Based on the vehicle's mass, target torque, and the slope of the vehicle's location, a first braking force is determined, i.e., the theoretical braking force required for the first vehicle to park at its current position is first determined. Then, based on environmental information about the vehicle's location, a braking force safety factor is determined, allowing for improvements in parking safety. Finally, based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced while keeping the first vehicle stationary. Thus, by reducing the braking force output by the braking system, the vehicle can use less electrical energy to maintain parking, achieving the effect of saving energy while ensuring parking safety.

[0011] Optionally, determining the first braking force of the first vehicle based on the vehicle mass, target torque, and the slope of the location of the first vehicle includes:

[0012] Based on the vehicle mass of the first vehicle and the slope, the downhill force of the first vehicle at its current position is determined; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, the target driving force is determined; when the first vehicle is in an uphill state, the absolute value of the difference between the downhill force and the target driving force is determined as the first braking force; when the first vehicle is in a downhill state, the absolute value of the sum of the downhill force and the target driving force is determined as the first braking force.

[0013] Alternatively, based on the vehicle mass of the first vehicle and the slope, determine the downhill force of the first vehicle at its current location; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, determine the target driving force; when the first vehicle is on an uphill slope, determine the absolute value of the difference between the downhill force and the target driving force to obtain a first value, and determine the first braking force by multiplying the first value by a parking coefficient; when the first vehicle is on a downhill slope, determine the absolute value of the sum of the downhill force and the target driving force to obtain a second value, and determine the first braking force by multiplying the second value by the parking coefficient, wherein the parking coefficient is determined based on the load and / or wind resistance within the first vehicle.

[0014] Optionally, the environmental information includes the slope of the location of the first vehicle, the relative distance between the first vehicle and the second vehicle, and the estimated collision time. Determining the braking force safety factor of the first vehicle based on the environmental information of its location includes:

[0015] If the slope is less than a first slope threshold and / or the expected collision time is greater than a first time threshold, the braking force safety factor of the first vehicle is obtained from the target correspondence based on the slope, the relative distance, and the expected collision time.

[0016] Optionally, the method further includes:

[0017] When the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, the braking system is controlled to output the first braking force.

[0018] Optionally, the step of reducing the braking force output by the braking system while keeping the first vehicle stationary, based on the reference braking force, the first braking force, the slope, and the braking force safety factor, includes:

[0019] Based on the reference braking force, the first braking force, and the slope, multiple rounds of braking force reduction are performed to obtain a second braking force. The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the braking force reduction process. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates.

[0020] Based on the second braking force, the reference braking force, and the braking force safety factor, the braking system is controlled to output braking force.

[0021] Optionally, the step of reducing the braking force in multiple rounds based on the reference braking force, the first braking force, and the slope to obtain the second braking force includes:

[0022] For the first round of braking force reduction in the multi-round braking force reduction, the reference braking force is subtracted from the preset braking force to obtain the braking force after the first round of braking force reduction.

[0023] For the reduction of braking force in the i-th round of the multi-round braking force reduction, when the slope is less than the second slope threshold, the braking force after the reduction of braking force in the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of braking force in the i-th round, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force, where i is an integer greater than or equal to 2;

[0024] When the slope is greater than or equal to the second slope threshold and less than the first slope threshold, the braking force after the reduction in the (i-1)th round is subtracted from the preset braking force to obtain the braking force after the reduction in the i-th round; after multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force, and the second slope threshold is less than the first slope threshold.

[0025] Optionally, controlling the braking system to output braking force based on the second braking force, the reference braking force, and the braking force safety factor includes:

[0026] Multiply the second braking force by the braking force safety factor to obtain the target braking force;

[0027] The braking system is controlled to output the smaller of the target braking force and the reference braking force.

[0028] Secondly, a braking force output device is provided, the device comprising:

[0029] The first determining module is configured to, when the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, control the braking system of the first vehicle to output a reference braking force and determine the first braking force of the first vehicle based on the vehicle mass, target torque and slope of the position of the first vehicle. The reference braking force is the maximum braking force output by the braking system during the braking process of the first vehicle being brought to a stop. The target torque is the torque output by the first vehicle when it is idling. The first braking force is the theoretical braking force required when the first vehicle is parked at its current position.

[0030] The second determining module is used to determine the braking force safety factor of the first vehicle based on the environmental information of the location of the first vehicle. The braking force safety factor is used to improve the parking safety of the first vehicle.

[0031] The braking force reduction module is used to reduce the braking force output by the braking system while keeping the first vehicle stationary, based on the reference braking force, the first braking force, the slope, and the braking force safety factor.

[0032] Optionally, the first determining module is used to:

[0033] Based on the vehicle mass of the first vehicle and the slope, the downhill force of the first vehicle at its current position is determined; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, the target driving force is determined; when the first vehicle is in an uphill state, the absolute value of the difference between the downhill force and the target driving force is determined as the first braking force; when the first vehicle is in a downhill state, the absolute value of the sum of the downhill force and the target driving force is determined as the first braking force.

[0034] Alternatively, based on the vehicle mass of the first vehicle and the slope, determine the downhill force of the first vehicle at its current location; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, determine the target driving force; when the first vehicle is on an uphill slope, determine the absolute value of the difference between the downhill force and the target driving force to obtain a first value, and determine the first braking force by multiplying the first value by a parking coefficient; when the first vehicle is on a downhill slope, determine the absolute value of the sum of the downhill force and the target driving force to obtain a second value, and determine the first braking force by multiplying the second value by the parking coefficient, wherein the parking coefficient is determined based on the load and / or wind resistance within the first vehicle.

[0035] Optionally, the environmental information includes the slope of the location of the first vehicle, the relative distance between the first vehicle and the second vehicle, and the estimated collision time. The second determining module is used to:

[0036] If the slope is less than a first slope threshold and / or the expected collision time is greater than a first time threshold, the braking force safety factor of the first vehicle is obtained from the target correspondence based on the slope, the relative distance, and the expected collision time.

[0037] Optionally, the device further includes:

[0038] The control module is configured to control the braking system to output the first braking force when the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold.

[0039] Optionally, the braking force output module is used for:

[0040] Based on the reference braking force, the first braking force, and the slope, multiple rounds of braking force reduction are performed to obtain a second braking force. The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the braking force reduction process. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates.

[0041] Based on the second braking force, the reference braking force, and the braking force safety factor, the braking system is controlled to output braking force.

[0042] Optionally, the braking force output module is used for:

[0043] For the first round of braking force reduction in the multi-round braking force reduction, the reference braking force is subtracted from the preset braking force to obtain the braking force after the first round of braking force reduction.

[0044] For the reduction of braking force in the i-th round of the multi-round braking force reduction, when the slope is less than the second slope threshold, the braking force after the reduction of braking force in the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of braking force in the i-th round, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force, where i is an integer greater than or equal to 2;

[0045] When the slope is greater than or equal to the second slope threshold and less than the first slope threshold, the braking force after the reduction in the (i-1)th round is subtracted from the preset braking force to obtain the braking force after the reduction in the i-th round; after multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force, and the second slope threshold is less than the first slope threshold.

[0046] Optionally, the braking force output module is used for:

[0047] Multiply the second braking force by the braking force safety factor to obtain the target braking force;

[0048] The braking system is controlled to output the smaller of the target braking force and the reference braking force.

[0049] Thirdly, a vehicle is provided, the vehicle comprising:

[0050] Memory, used to store executable program code;

[0051] A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the aforementioned braking force output method.

[0052] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described braking force output method.

[0053] Fifthly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the steps of the above-described braking force output method.

[0054] It is understood that the beneficial effects of the second, third, fourth, and fifth aspects mentioned above can be found in the relevant descriptions in the first aspect above, and will not be repeated here. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a schematic diagram of the implementation environment of a braking force output method provided in an embodiment of this application;

[0057] Figure 2 This is a schematic diagram of a braking force output method provided in an embodiment of this application;

[0058] Figure 3 This is a flowchart of a braking force output method provided in an embodiment of this application;

[0059] Figure 4 This is a schematic diagram of force analysis of a first vehicle provided in an embodiment of this application;

[0060] Figure 5 This is a flowchart of another braking force output method provided in the embodiments of this application;

[0061] Figure 6 This is a schematic diagram of the structure of a braking force output device provided in an embodiment of this application;

[0062] Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0064] It should be understood that "multiple" as mentioned in this application refers to two or more. In the description of this application, unless otherwise stated, " / " indicates "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist, for example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, to facilitate a clear description of the technical solutions of this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and that "first," "second," etc., do not necessarily imply differences.

[0065] Before describing the braking force output method provided in the embodiments of this application, the implementation environment provided in the embodiments of this application will be described first.

[0066] Figure 1 This is a schematic diagram illustrating the implementation environment of a braking force output method provided in an embodiment of this application. See also... Figure 1 , Figure 1 The vehicle 101 includes a braking system 102 and an automatic parking function 103.

[0067] The braking system 102 is used to output braking force when the vehicle decelerates or stops. The braking system 102 consists of a brake pedal, a master cylinder, brake fluid, brake lines, brakes, brake discs / drums, brake pads / shoes, brake boosters, etc., which is a traditional mechanical braking system.

[0068] When the driver presses the brake pedal, the pedal transmits force to the master cylinder via a mechanical or hydraulic connection. The piston in the master cylinder compresses the brake fluid, generating high pressure. This high-pressure brake fluid is then transmitted through the brake lines to the brakes at each wheel. The pistons in the brakes then push the brake pads or shoes, causing them to contact the brake discs or drums, generating friction. This friction converts the vehicle's kinetic energy into heat, slowing the vehicle down or bringing it to a stop.

[0069] In addition, the braking system includes an Electronic Parking Brake (EPB), which essentially replaces the traditional mechanical handbrake or foot brake with electronic control. Typically, vehicles have an EPB activation / deactivation button. When the driver presses the EPB button, a signal is sent to the ECU (Electronic Control Unit) to activate the parking brake. Once the vehicle is confirmed to be stationary, the ECU uses a motor to drive the brake calipers, which apply sufficient braking force to keep the wheels stationary.

[0070] Automatic parking assist 103 is a technology that assists the driver in automatically keeping the vehicle stationary when parking, without requiring continuous pressing of the brake pedal. Automatic parking assist 103 is widely used in scenarios such as waiting at traffic lights and starting on an incline. Generally, vehicles are equipped with an on / off button for automatic parking assist 103. When the driver presses the on button, automatic parking assist 103 is activated. Subsequently, when the driver presses the brake pedal to bring the vehicle to a complete stop and then releases the brake pedal, the system automatically detects this and uses the automatic parking assist function to keep the vehicle stationary. The driver can then easily start moving again by lightly pressing the accelerator pedal.

[0071] The working principle of the automatic parking brake function 103 is as follows: When the driver depresses the brake pedal and brings the vehicle to a complete stop, the wheel speed sensors detect that all wheels have stopped rotating. Simultaneously, the master cylinder detects pressure on the brake pedal, indicating that the braking system is fully engaged. When the brake pedal is subsequently released, with the automatic parking brake function 103 activated, the ECU sends a parking signal to the EPB. Normally, the EPB is activated immediately when the driver releases the brake pedal, allowing the EPB to drive the calipers via a motor to apply sufficient braking force (typically the maximum braking force applied when the driver depresses the brake pedal) to keep the vehicle stationary.

[0072] In this embodiment, the braking system 102 is mainly used to brake the vehicle 101. The automatic parking function 103 is mainly used to park the vehicle 101 using the braking force output method provided in this embodiment when the vehicle 101 is stopped.

[0073] The application scenarios of the embodiments of this application will be further described.

[0074] The braking force output method provided in this application can be applied to scenarios where the vehicle needs to be automatically parked when it stops. For example, the braking force output method provided in this application can be applied to scenarios where the vehicle is waiting at a red light, or to scenarios where the vehicle is parked on a slope.

[0075] For example, Figure 2 This is a schematic diagram illustrating a braking force output method provided in an embodiment of this application. See also... Figure 2 , Figure 2 It includes vehicle 201 and ramp 202, wherein vehicle 201 stops on ramp 202.

[0076] In the prior art, when using the automatic parking function, the maximum braking force of the vehicle 201 during the braking process is obtained, and then the vehicle 201 is parked on the slope 202 by applying the maximum braking force.

[0077] However, in reality, when vehicle 201 is parked on ramp 202, it may not be necessary to apply the maximum braking force. Applying a braking force less than the maximum braking force can also make vehicle 201 park automatically, which would waste the vehicle's electrical energy.

[0078] Therefore, this application provides a braking force output method that can determine a suitable braking force to save vehicle electrical energy.

[0079] Specifically, when vehicle 201 is brought to a stop and the brake pedal is released, the braking system of vehicle 201 is first controlled to output the maximum braking force during the stopping process to keep vehicle 201 stationary. Then, based on the vehicle mass, target torque, and slope of vehicle 201's location, the first braking force of vehicle 201 is determined, which is a theoretical braking force for parking at that location. Next, based on environmental information about vehicle 201's location, a braking force safety factor is determined. Finally, based on the maximum braking force during the stopping process, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced.

[0080] In this way, by reducing the braking force output by the braking system, the vehicle can use less electrical energy to maintain parking, thus achieving the effect of saving energy while ensuring parking safety.

[0081] The braking force output method provided in the embodiments of this application will be explained in detail below.

[0082] Figure 3 This is a flowchart illustrating a braking force output method provided in an embodiment of this application. This method can be applied to a vehicle's ECU. See also... Figure 3 The method includes the following steps.

[0083] Step 301: When the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, control the braking system of the first vehicle to output a reference braking force and determine the first braking force of the first vehicle based on the vehicle mass, target torque and slope of the location of the first vehicle.

[0084] The first vehicle being brought to a stop means that the brake pedal of the first vehicle is depressed until the vehicle comes to a complete stop.

[0085] The reference braking force is the maximum braking force output by the braking system during the braking process of the first vehicle coming to a stop. Since the maximum braking force during the braking process is sufficient to keep the vehicle stationary, outputting this reference braking force ensures that the vehicle remains stationary.

[0086] The target torque is the torque output by the first vehicle when it is idling. When the vehicle is idling, the engine needs to generate sufficient torque to overcome internal friction and other resistances. However, this torque is relatively small and is mainly used to maintain stable engine operation. Since the engine typically rotates at a fixed speed when idling, the target torque can also be fixed, and it can usually be stored in the first vehicle's memory before it leaves the factory.

[0087] The slope of the location of the first vehicle can be detected by the IMU (Inertial Measurement Unit) of the first vehicle.

[0088] The first braking force is the theoretical braking force required for the first vehicle to be parked in its current position; that is, the first braking force is the calculated braking force that can keep the first vehicle stationary in its current position.

[0089] In this scenario, when the first vehicle is brought to a stop and the brake pedal is released, the first vehicle's braking system is controlled to output a reference braking force to keep the vehicle stationary and prevent it from rolling backward. Then, based on the vehicle's mass, target torque, and the slope, the first braking force of the first vehicle is determined. A theoretical braking force that can keep the first vehicle stationary at its current position can then be calculated. This theoretical braking force can then be adjusted accordingly to minimize the braking force.

[0090] It is worth noting that before step 301, it is necessary to determine whether the first vehicle has been brought to a stop and whether the brake pedal has been released.

[0091] Specifically, when the brake pedal of the first vehicle is detected to be depressed, the wheel speed of the first vehicle is obtained; when the wheel speed of each wheel of the first vehicle is 0, it is determined that the first vehicle has been stopped; subsequently, when the brake pedal of the first vehicle is detected to be depressed, it is determined that the first vehicle has been stopped and the brake pedal has been released.

[0092] In this scenario, the stopping status of the first vehicle is determined by the wheel speed when the brake pedal is detected being depressed. If the wheel speed of all wheels of the first vehicle is 0, it means that the wheels of the first vehicle are no longer rotating, and the first vehicle has stopped. However, if the wheel speed of any wheel in the first vehicle is not 0, it is determined that the first vehicle has not yet stopped. If the brake pedal is subsequently released while the first vehicle is still stationary, it can be confirmed that the first vehicle has been brought to a complete stop and the brake pedal has been released.

[0093] Optionally, the determination of the first braking force of the first vehicle based on the vehicle mass, target torque, and slope of the location of the first vehicle can be achieved in the following two possible ways.

[0094] One possible implementation involves determining the downhill force of the first vehicle at its current location based on the vehicle's mass and the slope; determining the target driving force based on the target torque, the first vehicle's gear ratio, and the wheel radius; determining the first braking force as the absolute value of the difference between the downhill force and the target driving force when the first vehicle is on an uphill slope; and determining the first braking force as the absolute value of the sum of the downhill force and the target driving force when the first vehicle is on a downhill slope.

[0095] The downward force on the first vehicle at its current position is a downward component of the vehicle's weight along the slope, which is affected by gravity.

[0096] The target driving force is the driving force of the first vehicle when it is idling.

[0097] Because the first vehicle is subjected to various forces when on a slope, the braking force required to park it varies. Gravity exerts a component force along the slope, which is crucial for braking. Additionally, the vehicle may exhibit idling torque when parked uphill or downhill, resulting in a relatively low driving force. Therefore, when calculating the initial braking force, the downward force on the first vehicle at its current position and the target driving force of the target vehicle can be calculated.

[0098] Thus, the first braking force is calculated after performing the corresponding force analysis, which allows for accurate calculation of the first braking force.

[0099] The operation of determining the sliding force of the first vehicle at its location based on the vehicle mass and the slope can be as follows: Based on the vehicle mass and the slope, the sliding force of the first vehicle at its location is determined by the following formula (1).

[0100] F down =mgsinθ (1)

[0101] Among them, F down Let m be the downward force exerted by the first vehicle at its current position, g be the gravitational acceleration (usually taken as 9.8), and θ be the slope at the position of the first vehicle.

[0102] For example, the first vehicle has a mass of 1500 kg and is parked on a slope with an incline of 10°. The downward force exerted by the first vehicle at its current position is: F down =mgsinθ=1500×9.8×sin(10°)=2552.63N (Newtons).

[0103] The operation of determining the target driving force based on the target torque, the transmission ratio of the first vehicle and the wheel radius can be as follows: the target driving force is determined by the following formula (2) based on the target torque, the transmission ratio of the first vehicle and the wheel radius.

[0104]

[0105] Among them, F static Let T be the target driving force of the first vehicle, l be the target torque, l be the gear ratio of the first vehicle, and R be the wheel radius of the first vehicle.

[0106] For example, if the target torque of the first vehicle is 150 Nm, the gear ratio is 4, and the wheel radius is 0.3 meters, then the target driving force of the first vehicle is...

[0107] It's worth noting that when the first vehicle is going uphill, its driving force is upward along the slope. Therefore, the target driving force is also upward along the slope. In this case, the target driving force can offset part of the downward force. Thus, when the first vehicle is going uphill, to ensure the vehicle remains stationary, the absolute value of the difference between the downward force and the target driving force can be determined as the first braking force. For example, Figure 4 This is a schematic diagram of the force analysis of a first vehicle. See also... Figure 4 In (a), the first vehicle 401 is in an uphill state, and it has an upward target driving force and a downward sliding force on the slope.

[0108] When the first vehicle is going downhill, its driving force is downward along the slope. Therefore, the target driving force is also downward along the slope. In this case, to keep the vehicle stationary, the absolute value of the sum of the downhill force and the target driving force needs to be determined as the first braking force. See also Figure 4 In (b), the first vehicle 401 is in a downhill state, and it has a downward target driving force and a downward sliding force on the slope.

[0109] In addition, when the first vehicle is in an uphill state, the operation of determining the absolute value of the difference between the sliding force and the target driving force as the first braking force can be achieved by the following formula (3).

[0110] F a =|F down -F static | (3)

[0111] Among them, F a It serves as the primary braking force.

[0112] When the first vehicle is in a downhill state, the operation of determining the absolute value of the sum of the downhill force and the target driving force as the first braking force can be achieved by the following formula (4).

[0113] F a =|F down +F static | (4)

[0114] The second possible implementation involves determining the downhill force of the first vehicle at its current location based on its mass and the slope; determining the target driving force based on the target torque, the transmission ratio of the first vehicle, and the wheel radius; determining the absolute value of the difference between the downhill force and the target driving force when the first vehicle is on an uphill slope, obtaining a first value, and determining the first braking force by multiplying the first value by the parking coefficient; and determining the absolute value of the sum of the downhill force and the target driving force when the first vehicle is on a downhill slope, obtaining a second value, and determining the first braking force by multiplying the second value by the parking coefficient.

[0115] The parking coefficient is determined based on the load and / or wind resistance in the first vehicle. Alternatively, the parking coefficient can be pre-calibrated by a technician.

[0116] For the first vehicle to remain stationary, its braking force is affected by various factors, such as the load inside the vehicle (not just the vehicle's own weight) and the surrounding environment (wind, road surface, etc.). Therefore, in this embodiment, a parking coefficient can be set, and the first braking force can be determined based on this coefficient.

[0117] In this case, by setting a parking coefficient, multiple influencing factors can be taken into account when the first vehicle is parked at its current position, thereby obtaining a more accurate first braking force, which in turn ensures that the first braking force can keep the first vehicle stationary at its current position.

[0118] Among them, when the first vehicle is in an uphill state, the absolute value of the difference between the descent force and the target driving force is determined to obtain the first value. The operation of determining the first braking force by multiplying the first value and the parking coefficient can be achieved by the following formula (5).

[0119] F a =|F down -F static |×k (5)

[0120] Where κ is the parking coefficient.

[0121] When the first vehicle is in a downhill state, the absolute value of the sum of the sliding force and the target driving force is determined to obtain the second value. The operation of determining the first braking force by multiplying the second value and the parking coefficient can be achieved by the following formula (6).

[0122] F a =|F down +F static |×k (6)

[0123] Optionally, the operation of determining the parking coefficient can be as follows: obtaining the drag coefficient and frontal area of ​​the first vehicle, the wind speed and air density at the location of the first vehicle; determining the friction force required by the first vehicle at its location based on the vehicle mass, the slope, the drag coefficient and frontal area of ​​the first vehicle, the wind speed and air density at the location of the first vehicle; and determining the parking coefficient of the first vehicle based on the friction force and the sliding force required by the first vehicle at its location.

[0124] The frontal area of ​​the first vehicle is affected by the vehicle structure, and the drag coefficient is affected by the frontal area. Optionally, the drag coefficient and frontal area of ​​the first vehicle can be pre-stored in the memory of the first vehicle.

[0125] The first vehicle can be equipped with a wind speed sensor, which can be used to collect the wind speed at the location of the first vehicle when determining the parking coefficient.

[0126] The operation of determining the friction force required by the first vehicle at its location based on the vehicle mass, the slope, the drag coefficient and frontal area of ​​the first vehicle, the wind speed and air density at the location of the first vehicle can be as follows: the friction force required by the first vehicle at its location can be determined by the following formula (7) based on the vehicle mass, the slope, the drag coefficient and frontal area of ​​the first vehicle, the wind speed and air density at the location of the first vehicle.

[0127]

[0128] Among them, F 摩擦Let ρ be the frictional force required for the first vehicle to reach its current position, and υ be the air density. 风 B is the wind speed at the location of the first vehicle, C is the frontal area of ​​the first vehicle, and D is the wind speed at the location of the first vehicle. d Let be the drag coefficient of the first vehicle. It is the angle between the wind direction and the slope direction.

[0129] Optionally, the operation of determining the parking coefficient of the first vehicle based on the friction and sliding force required by the first vehicle at its position can be as follows: the parking coefficient of the first vehicle is determined by the following formula (8) based on the friction and sliding force required by the first vehicle at its position.

[0130]

[0131] In this situation, by taking into account various factors, a more accurate parking coefficient can be determined, thereby ensuring that the first vehicle remains stationary at its location.

[0132] The theoretical braking force required for the first vehicle to be parked at its current position can be determined through step 301 above. However, this initial braking force may not be small enough, so steps 302 and 303 below can be performed.

[0133] Step 302: Based on the environmental information of the location of the first vehicle, determine the braking force safety factor of the first vehicle. The braking force safety factor is used to improve the parking safety of the first vehicle.

[0134] The environmental information regarding the location of the first vehicle may include the slope of the first vehicle's location, the relative distance between the first and second vehicles, and the estimated time of collision. The second vehicle refers to the vehicle behind or in front of the first vehicle. For example, if the first vehicle is going uphill, the vehicle following behind it can be considered the second vehicle. Similarly, if the first vehicle is going downhill, the vehicle in front of it can be considered the second vehicle. The estimated time of collision refers to the time from the current moment until the collision occurs between the first and second vehicles.

[0135] The braking force safety factor is specifically used to improve the safety of the first vehicle during the reduction of braking force. The braking force safety factor is affected by the slope, the relative distance between the first and second vehicles, and the expected collision time. It should be understood that the greater the slope, the greater the risk of the first vehicle rolling backwards, and the greater the braking force required; therefore, the greater the braking force safety factor. Conversely, the smaller the relative distance between the first and second vehicles or the shorter the expected collision time, the less likely the first vehicle is to roll backwards, thus requiring greater braking force, and in this case, a greater braking force safety factor is also required to ensure that the first vehicle remains completely stationary in its position.

[0136] In this case, by determining the braking force safety factor of the first vehicle based on the environmental information of the first vehicle's location, the braking force safety factor can be used to ensure that the vehicle remains completely stationary on the slope when parked at its location, thereby improving the parking safety of the first vehicle.

[0137] Optionally, step 302 can be performed as follows: if the slope is less than a first slope threshold and / or the expected collision time is greater than a first time threshold, obtain the braking force safety factor of the first vehicle from the target correspondence based on the slope, the relative distance between the first vehicle and the second vehicle, and the expected collision time.

[0138] The first slope threshold and the first time threshold can be preset, and the first slope threshold can be set to a smaller value, while the first time threshold can be set to a larger value.

[0139] The target correspondence includes the relationship between slope, relative distance, estimated collision time, and braking force safety factor. This correspondence includes multiple slopes, multiple relative distances, multiple estimated collision times, and multiple braking force safety factors. Specifically, one slope, one relative distance, and one estimated collision time correspond to one braking force safety factor.

[0140] For example, Table 1 shows an example of target correspondence. Table 1 includes multiple slopes, multiple relative distances, multiple estimated collision times, and multiple braking force safety factors. Each set of slope, relative distance, and estimated collision time corresponds to a braking force safety factor. For instance, if the slope is 10°, the relative distance is 10 meters, and the estimated collision time is 30 seconds, then the corresponding braking force safety factor can be determined to be 1 from Table 1 below.

[0141] Table 1

[0142] slope relative distance Expected collision time Braking force safety factor 10° 10 meters 30 seconds 1 20° 20 meters 20 seconds 1.2 30° 10 meters 10 seconds 1.3 …… …… …… ……

[0143] The embodiments of this application are merely illustrative examples of the target correspondence using Table 1 above, and do not constitute a limitation on the embodiments of this application.

[0144] Since the braking force safety factor is a factor used to improve the safety of the first vehicle during the process of reducing braking force, if the slope is too steep and the expected collision time is too short, the vehicle may roll back down the slope if the braking force is reduced. Therefore, the braking force cannot be reduced in this case. Therefore, in this embodiment of the application, the braking force safety factor is determined only when the slope is less than the first slope threshold and / or the expected collision time is greater than the first time threshold.

[0145] In this situation, if the slope is less than the first slope threshold and / or the expected collision time is greater than the first time threshold, it indicates that the slope is relatively small and / or the expected collision time is relatively large. Therefore, when reducing the braking force, the risk of the first vehicle rolling backward is relatively small. Thus, the operation of reducing the braking force can be performed, and the braking force safety factor can be determined.

[0146] If the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, it indicates that the slope is large and / or the expected collision time is small. In this case, the risk of the vehicle rolling backward is high when the braking force is reduced. Therefore, the braking force cannot be reduced, and there is no need to determine the braking force safety factor.

[0147] Optionally, if the slope is greater than or equal to a first slope threshold and / or the expected collision time is less than or equal to a first time threshold, the braking system is controlled to output a first braking force.

[0148] Since the first vehicle may roll back down the slope when the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, there is a risk of collision after the braking force is reduced. Therefore, the braking force is not reduced in this case. Instead, the braking system can be directly controlled to output the first braking force, which is the theoretical braking force required for the first vehicle to be parked at its current position.

[0149] Optionally, if the slope is greater than or equal to a first slope threshold and / or the expected collision time is less than or equal to a first time threshold, the braking system is controlled to output the smaller of the first braking force and the reference braking force.

[0150] In this case, the first braking force is compared with the reference braking force, and the braking system is then controlled to output the smaller of the first braking force and the reference braking force, thereby achieving the purpose of energy saving.

[0151] Since the first braking force and the reference braking force are braking forces that can ensure the first vehicle remains stationary at its current position, when the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, the braking system outputs the corresponding braking force, which can ensure safety while keeping the first vehicle stationary at its current position, thus improving parking safety.

[0152] It is worth noting that before determining the braking force safety factor, it is also necessary to determine whether there is a second vehicle behind the first vehicle; if there is a second vehicle behind the first vehicle, obtain the relative distance and relative speed between the first vehicle and the second vehicle; divide the relative distance by the relative speed to obtain the estimated collision time.

[0153] Optionally, the first vehicle may be equipped with radar, which can then be used to collect the relative distance and relative speed between the first vehicle and the second vehicle.

[0154] Alternatively, the operation to determine whether there is a second vehicle behind the first vehicle can be as follows: capture a rear image using the camera of the first vehicle; output the rear image to the vehicle recognition model; process the rear image using the vehicle recognition model and output the recognition result; if the recognition result indicates that there is a vehicle, determine that there is a second vehicle behind the first vehicle; if the recognition result indicates that there is no vehicle, determine that there is no second vehicle behind the first vehicle.

[0155] The vehicle recognition model is used to identify whether a vehicle exists in an image. Optionally, the vehicle recognition model can be a convolutional neural network model or other models capable of object detection; this application embodiment does not limit this. For example, the vehicle recognition model can be the YOLO (You Only Look Once) model, Fast R-CNN (Fast Region-based Convolutional Neural Network), etc.

[0156] Therefore, using a neural network model to determine whether there is a second vehicle behind the first vehicle makes it easier to determine whether there is a vehicle behind the first vehicle, thereby improving vehicle detection efficiency.

[0157] The braking force safety factor of the first vehicle during the braking force reduction process can be determined through step 302 above. Therefore, the braking force can be reduced accordingly, that is, the following step 303 is to be executed.

[0158] Step 303: Based on the reference braking force, the first braking force, the slope, and the braking force safety factor, reduce the braking force output by the braking system while keeping the first vehicle stationary.

[0159] In this situation, by reducing the braking force output by the braking system based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force of the first vehicle can be reduced while ensuring safety. This allows the first vehicle to be kept stationary at its current position with a smaller braking force, thereby saving energy.

[0160] Specifically, the operation of step 303 may include the following steps (1)-(2).

[0161] (1) Based on the reference braking force, the first braking force and the slope, the braking force is reduced in multiple rounds to obtain the second braking force.

[0162] The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the reduction of braking force. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates.

[0163] The wheel speed sensor consists of a permanent magnet, a coil, and a gear rotor. The permanent magnet generates a constant magnetic field, the coil is wrapped around the permanent magnet, and the gear rotor is fixed to the vehicle and rotates with the wheels.

[0164] As the gear rotor rotates, its teeth periodically move closer to and further away from the permanent magnet. When a tooth approaches the permanent magnet, the magnetic field changes, causing a changing magnetic field to be generated in the coil. This changing magnetic field induces a voltage signal in the coil. Due to the periodic movement of the teeth, the voltage signal generated in the coil will appear as pulses, which is the pulse signal described in the embodiments of this application. The wheel speed is then determined based on the number of pulses.

[0165] The entire process is essentially based on the reference braking force, the first braking force, and the slope. During multiple rounds of braking force reduction, pulse signals are continuously collected. That is, a pulse signal is collected every time the braking force is reduced, until a pulse signal is collected. The second braking force is the braking force at which the pulse signal is first collected.

[0166] In this situation, the generation of a pulse signal indicates that the gear rotor has just begun to move. Therefore, the reduction in braking force is stopped promptly as soon as the gear rotor starts moving, preventing the first vehicle from rolling backward and ensuring that a relatively small braking force is achieved. In this way, the braking force can be reduced as much as possible while ensuring safety, allowing the vehicle to be parked with appropriate braking force.

[0167] Optionally, the operation of step (1) may include the following steps (a)-step (b) or steps (a)-step (c).

[0168] (a) For the first round of braking force reduction in a multi-round braking force reduction, the reference braking force is subtracted from the preset braking force to obtain the braking force after the first round of braking force reduction.

[0169] The preset braking force can be set in advance, and the preset braking force can be set according to actual needs. For example, the preset braking force can be set to a smaller value.

[0170] In this situation, it's equivalent to first reducing the maximum braking force by the preset braking force to achieve the first reduction in braking force. Furthermore, if the preset braking force is relatively small, the maximum braking force is first reduced by a smaller amount to obtain the braking force after the first reduction.

[0171] (b) For the reduction of braking force in the i-th round of the multi-round braking force reduction, if the slope is less than the second slope threshold, the braking force after the reduction of braking force in the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of braking force in the i-th round, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force.

[0172] If the second slope threshold is less than the first slope threshold, then step (b) above is the scheme executed when the slope is very small. That is, when the slope is very small, the maximum braking force is continuously reduced in a gradient until the wheel speed sensor collects a pulse signal.

[0173] Because the probability of the first vehicle slipping on a very gentle slope is very small when the braking force is reduced, the braking force can be reduced continuously until a pulse signal is collected.

[0174] In addition, the reduction of braking force in multiple rounds is essentially a reduction of the maximum braking force in a certain gradient. When the preset braking force is small, the maximum braking force is gradually reduced in a small gradient. This allows for more accurate acquisition of pulse signals during the reduction of braking force, and thus more accurate determination of the second braking force.

[0175] The following example illustrates the braking force reduction process when the slope is less than the second slope threshold.

[0176] For example, if the maximum braking force is 100 and the preset braking force is 5, after the first round of braking force reduction, the braking force after the first round of braking force reduction is 95.

[0177] For the second round of braking force reduction, the braking force (95) after the first round of braking force reduction is subtracted from the preset braking force (5) to obtain the braking force (90) after the second round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. After the second round of braking force reduction, the wheel speed sensor does not collect pulse signals.

[0178] For the third round of braking force reduction, the braking force (90) after the second round of braking force reduction is subtracted from the preset braking force (5) to obtain the braking force (85) after the third round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. After the third round of braking force reduction, the wheel speed sensor does not collect pulse signals.

[0179] For the reduction of the fourth round braking force, the braking force (85) after the reduction of the third round braking force is subtracted from the preset braking force (5) to obtain the braking force (80) after the reduction of the fourth round braking force. The wheel speed sensor of the first vehicle continuously collects pulse signals. At this time, after the fourth round braking force is reduced, the wheel speed sensor collects pulse signals and stops reducing the braking force. At this time, the second braking force is determined to be 80.

[0180] Optionally, when the braking force is reduced to the first braking force, the preset braking force can be appropriately reduced, and the braking force can be reduced in subsequent stages based on the reduced preset braking force.

[0181] Since the initial braking force is the theoretical braking force required for the vehicle to stop at its current position, if the braking force is reduced too much in the future, the probability of the vehicle rolling backward will increase. Therefore, the braking force can be reduced in smaller increments in the future.

[0182] Using the example above, if the first braking force is 80, and the braking force is reduced to 80 after the fourth round of braking, but the wheel speed sensor has not yet collected a pulse signal, then the preset braking force is reduced. Let's assume the reduced preset braking force is 2.

[0183] For the fifth round of braking force reduction, the reduced preset braking force (2) is subtracted from the braking force (80) after the fourth round of braking force reduction to obtain the braking force (78) after the fifth round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. At this time, after the fifth round of braking force reduction, the wheel speed sensor collects pulse signals and stops reducing the braking force. At this time, the second braking force is determined to be 78.

[0184] Optionally, step (b) can also be performed as follows: for the i-th round of braking force reduction in multi-round braking force reduction, if the slope is less than the second slope threshold and / or the expected collision time is greater than the second time threshold, the braking force after the reduction of the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of the i-th round, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force.

[0185] The second time threshold can be preset, and the second time threshold can be set according to the relationship that the second time threshold is greater than the first time threshold.

[0186] In this scenario, the slope is very gentle and / or the expected collision time is very long. Since the probability of the first vehicle rolling off the slope is low when the slope is very gentle or the expected collision time is very long, and even if the first vehicle does roll off the slope, it may not cause damage, the above steps can be performed when the slope is very gentle and / or the expected collision time is very long.

[0187] (c) When the slope is greater than or equal to the second slope threshold and less than the first slope threshold, the braking force after the reduction in the (i-1)th round is subtracted from the preset braking force to obtain the braking force after the reduction in the i-th round; after multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force.

[0188] If the slope is greater than or equal to the second slope threshold but less than the first slope threshold, it indicates that the slope is slightly large, but not particularly large. In this case, if a pulse signal is not collected after the braking force is reduced to the first braking force, the first braking force will be determined as the second braking force.

[0189] Since the probability of the first vehicle rolling back is slightly higher when the slope is slightly steeper, if the braking force has been reduced to the first braking force and no pulse signal has been collected, further reduction of the braking force may cause the vehicle to roll back. Therefore, the first braking force can be determined as the second braking force.

[0190] In this situation, if no pulse signal is collected after multiple rounds of braking force reduction to the first braking force, the first braking force is determined as the second braking force, which can ensure that the first vehicle will not roll back.

[0191] The following example illustrates the scheme implemented when the slope is greater than or equal to the second slope threshold and less than the first slope threshold.

[0192] For example, the maximum braking force is 100, the first braking force is 80, the preset braking force is 5, and after the first round of braking force reduction, the braking force after the first round of braking force reduction is 95.

[0193] For the second round of braking force reduction, the braking force (95) after the first round of braking force reduction is subtracted from the preset braking force (5) to obtain the braking force (90) after the second round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. After the second round of braking force reduction, the wheel speed sensor does not collect pulse signals.

[0194] For the third round of braking force reduction, the braking force (90) after the second round of braking force reduction is subtracted from the preset braking force (5) to obtain the braking force (85) after the third round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. After the third round of braking force reduction, the wheel speed sensor does not collect pulse signals.

[0195] For the fourth round of braking force reduction, the preset braking force (5) is subtracted from the braking force (85) after the third round of braking force reduction to obtain the braking force (80) after the fourth round of braking force reduction. The wheel speed sensor of the first vehicle continuously collects pulse signals. After the fourth round of braking force reduction, the wheel speed sensor has not yet collected pulse signals. At this time, the first braking force (80) is determined as the second braking force.

[0196] Optionally, step (c) can also be performed as follows: for the i-th round of braking force reduction in multiple rounds of braking force reduction, if the slope is greater than or equal to the second slope threshold and less than the first slope threshold and / or the expected collision time is less than the second time threshold and greater than the first time threshold, the braking force after the (i-1)-th round of reduction is subtracted from the preset braking force to obtain the braking force after the i-th round of braking force reduction; after multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force.

[0197] In this case, the slope is slightly steep and / or the expected collision time is slightly longer. Since the probability of the first vehicle rolling back increases if the braking force is reduced too much when the slope is slightly steep or the expected collision time is slightly longer, the rolling back of the first vehicle may cause damage to the first vehicle. Therefore, the above steps can be performed when the slope is greater than or equal to the second slope threshold and less than the first slope threshold and / or the expected collision time is less than the second time threshold and greater than the first time threshold.

[0198] (2) Based on the second braking force, the reference braking force and the braking force safety factor, control the output braking force of the braking system.

[0199] Since the second braking force is the braking force that brings the first vehicle to a standstill after the braking force has been reduced, based on the second braking force, the reference braking force, and the braking force safety factor, the braking system can be controlled to output a smaller braking force. This is done while ensuring the parking safety of the first vehicle, thus achieving the effect of saving energy.

[0200] Specifically, step (2) can be performed by multiplying the second braking force by the braking force safety factor to obtain the target braking force; and controlling the braking system to output the smaller of the target braking force and the reference braking force.

[0201] In this case, multiplying the second braking force by the braking force safety factor yields the target braking force that can ensure the parking safety of the first vehicle. Then, the smaller braking force between the target braking force and the reference braking force is selected for output, so that the braking system of the first vehicle can always output a smaller braking force while ensuring parking safety, thereby saving energy.

[0202] For example, the reference braking force is 100, the second braking force is 80, and the braking force safety factor is 1.

[0203] First, multiply the second braking force (80) by the braking force safety factor (1) to obtain the target braking force as 80. Then, compare the target braking force (80) with the reference braking force (100) to determine that the target braking force is smaller, and then control the braking system to output a smaller target braking force (80).

[0204] To facilitate understanding, we will now combine... Figure 5 The braking force output method provided in the embodiments of this application will be described by way of example. For example, Figure 5 For a flowchart of another braking force output method provided in the embodiments of this application, please refer to [link / reference]. Figure 5 , Figure 5 This includes steps 501-509.

[0205] Step 501: When the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, control the braking system of the first vehicle to output a reference braking force.

[0206] Step 502: Determine the first braking force of the first vehicle based on the vehicle mass, target torque, and slope of the location of the first vehicle.

[0207] Step 503: Determine whether the slope is less than the first slope threshold and / or whether the expected collision time is greater than the first time threshold.

[0208] Step 504: If the slope is less than a first slope threshold and / or the expected collision time is greater than a first time threshold, determine the braking force safety factor of the first vehicle. If the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, control the braking system to output a first braking force.

[0209] Step 505: Determine whether the slope is less than the second slope threshold and / or whether the expected collision time is greater than the second time threshold.

[0210] Step 506: If the slope is less than the second slope threshold and / or the expected collision time is greater than the second time threshold, the reference braking force is reduced in multiple rounds until the wheel speed sensor collects a pulse signal. The braking force at which the wheel speed sensor begins to collect a pulse signal is determined as the second braking force.

[0211] Step 507: If the slope is greater than or equal to the second slope threshold and less than the first slope threshold and / or the expected collision time is less than or equal to the second time threshold and greater than the first time threshold, and no pulse signal is collected after multiple rounds of braking force reduction of the reference braking force, then the first braking force is determined as the second braking force.

[0212] Step 508: Multiply the second braking force by the braking force safety factor to obtain the target braking force.

[0213] Step 509: Control the braking system to output the smaller of the target braking force and the reference braking force.

[0214] In this embodiment, when the first vehicle is brought to a stop and the brake pedal is released, the ECU controls the braking system of the first vehicle to output a reference braking force. Based on the vehicle's mass, target torque, and the slope of the vehicle's location, a first braking force is determined, i.e., the theoretical braking force required for the first vehicle to park at its current position is first determined. Then, based on environmental information about the vehicle's location, a braking force safety factor is determined, allowing for improvements in parking safety. Finally, based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced while keeping the first vehicle stationary. Thus, by reducing the braking force output by the braking system, the vehicle can use less electrical energy to maintain parking, achieving the effect of saving energy while ensuring parking safety.

[0215] Figure 6 This is a schematic diagram of a braking force output device provided in an embodiment of this application. This braking force output device can be implemented as part or all of a vehicle by software, hardware, or a combination of both. The vehicle can be described below. Figure 7 The vehicle shown. See also Figure 6 The device includes: a first determining module 601, a second determining module 602, and a braking force reduction module 603.

[0216] The first determining module 601 is used to control the braking system of the first vehicle to output a reference braking force and determine the first braking force of the first vehicle based on the vehicle mass, target torque and slope of the first vehicle's location when the first vehicle is stopped and the brake pedal of the first vehicle is released. The reference braking force is the maximum braking force output by the braking system during the stopping process of the first vehicle, the target torque is the torque output when the first vehicle is idling, and the first braking force is the theoretical braking force required when the first vehicle is parked at its current location.

[0217] The second determining module 602 is used to determine the braking force safety factor of the first vehicle based on the environmental information of the location of the first vehicle. The braking force safety factor is used to improve the parking safety of the first vehicle.

[0218] The braking force reduction module 603 is used to reduce the braking force output by the braking system while keeping the first vehicle stationary, based on a reference braking force, a first braking force, the slope, and a braking force safety factor.

[0219] Optionally, the first determining module 601 is used for:

[0220] Based on the vehicle mass of the first vehicle and the slope, determine the downhill force of the first vehicle at its current position; based on the target torque, the transmission ratio of the first vehicle and the wheel radius, determine the target driving force; when the first vehicle is in an uphill state, determine the absolute value of the difference between the downhill force and the target driving force as the first braking force; when the first vehicle is in a downhill state, determine the absolute value of the sum of the downhill force and the target driving force as the first braking force.

[0221] Alternatively, based on the vehicle mass of the first vehicle and the slope, determine the downhill force of the first vehicle at its current location; based on the target torque, the transmission ratio of the first vehicle, and the wheel radius, determine the target driving force; when the first vehicle is on an uphill slope, determine the absolute value of the difference between the downhill force and the target driving force to obtain a first value, and determine the first braking force by multiplying the first value by a parking coefficient; when the first vehicle is on a downhill slope, determine the absolute value of the sum of the downhill force and the target driving force to obtain a second value, and determine the first braking force by multiplying the second value by a parking coefficient, which is determined based on the load and / or wind resistance inside the first vehicle.

[0222] Optionally, the environmental information includes the slope of the location of the first vehicle, the relative distance between the first vehicle and the second vehicle, and the estimated collision time. The second determining module 602 is used for:

[0223] If the slope is less than the first slope threshold and / or the expected collision time is greater than the first time threshold, the braking force safety factor of the first vehicle is obtained from the target correspondence based on the slope, relative distance and expected collision time.

[0224] Optionally, the device further includes:

[0225] The control module is used to control the braking system to output a first braking force when the slope is greater than or equal to a first slope threshold and / or the expected collision time is less than or equal to a first time threshold.

[0226] Optionally, the braking force output module 603 is used for:

[0227] Based on the reference braking force, the first braking force, and the slope, multiple rounds of braking force reduction are performed to obtain the second braking force. The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the braking force reduction process. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates.

[0228] The braking system outputs braking force based on the second braking force, the reference braking force, and the braking force safety factor.

[0229] Optionally, the braking force output module 603 is used for:

[0230] For the first round of braking force reduction in this multi-round braking force reduction, the reference braking force is subtracted from the preset braking force to obtain the braking force after the first round of braking force reduction;

[0231] For the i-th round of braking force reduction in the multi-round braking force reduction, when the slope is less than the second slope threshold, the braking force after the reduction of the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of the i-th round braking force, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force, where i is an integer greater than or equal to 2;

[0232] If the slope is greater than or equal to the second slope threshold and less than the first slope threshold, the braking force after the reduction in the (i-1)th round is subtracted from the preset braking force to obtain the braking force after the reduction in the i-th round. After multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force, and the second slope threshold is less than the first slope threshold.

[0233] Optionally, the braking force output module 603 is used for:

[0234] Multiply the second braking force by the braking force safety factor to obtain the target braking force;

[0235] The control braking system outputs the smaller of the target braking force and the reference braking force.

[0236] In this embodiment, when the first vehicle is brought to a stop and the brake pedal is released, the braking system of the first vehicle outputs a reference braking force. Based on the vehicle's mass, target torque, and the slope of the vehicle's location, a first braking force is determined; that is, the theoretical braking force required for the first vehicle to park at its current position is first determined. Then, based on environmental information about the vehicle's location, a braking force safety factor is determined, allowing for improved parking safety. Finally, based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced while keeping the first vehicle stationary. Thus, by reducing the braking force output by the braking system, the vehicle can use less electrical energy to maintain parking, achieving the effect of saving energy while ensuring parking safety.

[0237] It should be noted that the braking force output device provided in the above embodiments is only illustrated by the division of the above functional modules when controlling the braking system to output braking force. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0238] The functional units and modules in the above embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of the embodiments of this application.

[0239] The braking force output device and braking force output method embodiments provided in the above embodiments belong to the same concept. The specific working process and technical effects of the units and modules in the above embodiments can be found in the method embodiment section, and will not be repeated here.

[0240] Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0241] For example, such as Figure 7 As shown, the vehicle 700 includes a memory 71 and a processor 70, wherein the memory 71 stores executable program code 72, and the processor 70 is used to call and execute the executable program code 72 to perform the aforementioned braking force output method.

[0242] This embodiment can divide the vehicle into functional modules according to the above method example. For example, each function can be assigned to a separate module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0243] When each functional module is divided according to its corresponding function, the vehicle may include: a first determining module, a second determining module, and a braking force reduction module. It should be noted that all relevant content regarding the steps involved in the above method embodiments can be referenced from the functional descriptions of the corresponding functional modules, and will not be repeated here.

[0244] The vehicle provided in this embodiment is used to execute the above-described method of braking force output, and therefore can achieve the same effect as the above-described implementation method.

[0245] When using integrated units, the vehicle may include a processing module and a storage module. The processing module is used to control and manage the vehicle's actions. The storage module is used to support the vehicle in executing corresponding program code and data.

[0246] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits shown in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0247] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, it causes the computer to execute the above-described related method steps to achieve the above-described method for outputting braking force in the above embodiment.

[0248] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned related steps to achieve the above-described method for outputting braking force in the above embodiment.

[0249] In this embodiment, the vehicle, computer-readable storage medium, computer program product, or chip are all used to execute the method described above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects of the method described above, and will not be repeated here.

[0250] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0251] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are illustrative; for instance, the division of modules or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0252] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for outputting braking force, characterized in that, The method includes: When the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, the braking system of the first vehicle is controlled to output a reference braking force and a first braking force of the first vehicle is determined based on the vehicle mass, target torque and slope of the first vehicle's location. The reference braking force is the maximum braking force output by the braking system during the braking process of the first vehicle being brought to a stop, the target torque is the torque output by the first vehicle when it is idling, and the first braking force is the theoretical braking force required when the first vehicle is parked at its current location. Based on the environmental information of the location of the first vehicle, the braking force safety factor of the first vehicle is determined, and the braking force safety factor is used to improve the parking safety of the first vehicle. Based on the reference braking force, the first braking force, the slope, and the braking force safety factor, the braking force output by the braking system is reduced while keeping the first vehicle stationary. The method of reducing the braking force output by the braking system while keeping the first vehicle stationary, based on the reference braking force, the first braking force, the slope, and the braking force safety factor, includes: Based on the reference braking force, the first braking force, and the slope, multiple rounds of braking force reduction are performed to obtain a second braking force. The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the braking force reduction process. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates. Based on the second braking force, the reference braking force, and the braking force safety factor, the braking system is controlled to output braking force.

2. The method as described in claim 1, characterized in that, Determining the first braking force of the first vehicle based on its mass, target torque, and the slope of its location includes: Based on the vehicle mass of the first vehicle and the slope, the downhill force of the first vehicle at its current position is determined; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, the target driving force is determined; when the first vehicle is in an uphill state, the absolute value of the difference between the downhill force and the target driving force is determined as the first braking force; when the first vehicle is in a downhill state, the absolute value of the sum of the downhill force and the target driving force is determined as the first braking force. Alternatively, based on the vehicle mass of the first vehicle and the slope, determine the downhill force of the first vehicle at its current location; based on the target torque, the gear ratio of the first vehicle, and the wheel radius, determine the target driving force; when the first vehicle is on an uphill slope, determine the absolute value of the difference between the downhill force and the target driving force to obtain a first value, and determine the first braking force by multiplying the first value by a parking coefficient; when the first vehicle is on a downhill slope, determine the absolute value of the sum of the downhill force and the target driving force to obtain a second value, and determine the first braking force by multiplying the second value by the parking coefficient, wherein the parking coefficient is determined based on the load and / or wind resistance within the first vehicle.

3. The method as described in claim 1, characterized in that, The environmental information includes the slope of the location of the first vehicle, the relative distance between the first vehicle and the second vehicle, and the estimated collision time. Determining the braking force safety factor of the first vehicle based on the environmental information of its location includes: If the slope is less than a first slope threshold and / or the expected collision time is greater than a first time threshold, the braking force safety factor of the first vehicle is obtained from the target correspondence based on the slope, the relative distance, and the expected collision time.

4. The method as described in claim 3, characterized in that, The method further includes: When the slope is greater than or equal to the first slope threshold and / or the expected collision time is less than or equal to the first time threshold, the braking system is controlled to output the first braking force.

5. The method as described in claim 1, characterized in that, The process of reducing the braking force in multiple rounds based on the reference braking force, the first braking force, and the slope to obtain the second braking force includes: For the first round of braking force reduction in the multi-round braking force reduction, the reference braking force is subtracted from the preset braking force to obtain the braking force after the first round of braking force reduction. For the reduction of braking force in the i-th round of the multi-round braking force reduction, when the slope is less than the second slope threshold, the braking force after the reduction of braking force in the (i-1)-th round is subtracted from the preset braking force to obtain the braking force after the reduction of braking force in the i-th round, until the wheel speed sensor of the first vehicle begins to collect pulse signals; the braking force that makes the wheel speed sensor begin to collect pulse signals is determined as the second braking force, where i is an integer greater than or equal to 2; When the slope is greater than or equal to the second slope threshold and less than the first slope threshold, the braking force after the reduction in the (i-1)th round is subtracted from the preset braking force to obtain the braking force after the reduction in the i-th round; after multiple rounds of braking force reduction to the first braking force, if the wheel speed sensor does not collect a pulse signal, the first braking force is determined as the second braking force, and the second slope threshold is less than the first slope threshold.

6. The method as described in claim 1, characterized in that, The step of controlling the braking system to output braking force based on the second braking force, the reference braking force, and the braking force safety factor includes: Multiply the second braking force by the braking force safety factor to obtain the target braking force; The braking system is controlled to output the smaller of the target braking force and the reference braking force.

7. A braking force output device, characterized in that, The device includes: The first determining module is configured to, when the first vehicle is brought to a stop and the brake pedal of the first vehicle is released, control the braking system of the first vehicle to output a reference braking force and determine the first braking force of the first vehicle based on the vehicle mass, target torque and slope of the position of the first vehicle. The reference braking force is the maximum braking force output by the braking system during the braking process of the first vehicle being brought to a stop. The target torque is the torque output by the first vehicle when it is idling. The first braking force is the theoretical braking force required when the first vehicle is parked at its current position. The second determining module is used to determine the braking force safety factor of the first vehicle based on the environmental information of the location of the first vehicle. The braking force safety factor is used to improve the parking safety of the first vehicle. A braking force reduction module is used to reduce the braking force output by the braking system while keeping the first vehicle stationary, based on the reference braking force, the first braking force, the slope, and the braking force safety factor. The braking force reduction module is specifically used to: reduce the braking force in multiple rounds based on the reference braking force, the first braking force, and the slope to obtain a second braking force. The second braking force is the braking force that causes the wheel speed sensor of the first vehicle to start collecting pulse signals during the braking force reduction process. The pulse signal is the electrical signal generated when the gear rotor fixed on the wheel of the first vehicle rotates. Based on the second braking force, the reference braking force, and the braking force safety factor, the braking system is controlled to output braking force.

8. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 6.

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