Slope parking auxiliary control method, device and equipment

Abstract

The invention provides a hill-holding auxiliary control method, device and equipment. The method comprises the steps of determining whether a target vehicle is in a slope sliding state according to a current state of the target vehicle; if the target vehicle is in the slope sliding state, the target vehicle enters a slope parking auxiliary state, and the current instruction torque of the target vehicle and the current rotating speed value of a driving motor on the target vehicle are obtained; the current instruction torque is an instruction torque sent by a vehicle control unit of the target vehicle to a driving motor when the target vehicle is in the slope sliding state; according to the current instruction torque and the current rotating speed value, the hill-holding auxiliary output torque of the driving motor is determined; the torque of the driving motor is controlled to be changed from the current instruction torque to the hill-holding auxiliary output torque, and the zero rotating speed is maintained; and after the target vehicle enters the hill-holding auxiliary state, if it is detected that the target vehicle meets the preset exit condition of the hill-holding auxiliary state, the torque of the driving motor is controlled to be changed from the hill-holding auxiliary output torque to the current instruction torque. Therefore, slope parking assistance is achieved, slope slipping is avoided, sensitivity is high, and the cost of the whole vehicle is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle control, and more particularly, to a hill-hold assist control method, device, and equipment. Background Art

[0002] With the rapid development of the automotive industry, new energy vehicles are becoming increasingly common. New energy vehicles are not only widely used in passenger cars but also have developed into the field of commercial vehicles.

[0003] For commercial vehicles, traditional fuel vehicles generally use mechanical handbrakes or auto hold systems to achieve hill parking in cooperation with the transmission locking mechanism and the braking system. However, due to the fundamental differences in the power system structure of pure electric vehicles, they are prone to reverse rolling when starting on a slope, posing a great safety hazard. Currently, some pure electric vehicles achieve anti-rolling through HAC (hill-start assist system), which results in high vehicle costs and low reliability. Most of the existing technologies are aimed at achieving hill starts or hill holds for passenger cars, where the vehicle mass change is small and it is easy to implement. However, this method is less applicable to commercial vehicles with large changes in vehicle load. Summary of the Invention

[0004] The purpose of the present invention is to provide a hill-hold assist control method, device, and equipment to solve the problems such as poor applicability in the existing technology.

[0005] To achieve the above purpose, the technical solutions adopted in the embodiments of the present application are as follows: In a first aspect, an embodiment of the present application provides a hill-hold assist control method, the method including: Determine whether the target vehicle is in a rolling state according to the current state of the target vehicle; If the target vehicle is in a rolling state, enter the hill-hold assist state, and obtain the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle; the current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when in the rolling state; Determine the hill-hold assist output torque of the drive motor according to the current command torque and the current rotational speed value; Control the torque of the drive motor to change from the current command torque to the hill-hold assist output torque and maintain zero rotational speed; After entering the hill-hold assist state, if it is detected that the target vehicle meets the preset exit conditions of the hill-hold assist state, control the torque of the drive motor to change from the hill-hold assist output torque to the current command torque.

[0006] Optionally, the current state of the target vehicle includes: vehicle driving state, gear position, and the current rotational speed direction of the drive motor; determining whether the target vehicle is in a rollback state according to the current state of the target vehicle includes: Determine whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position; If the expected rotational speed direction is inconsistent with the current rotational speed direction, determine that the target vehicle is in a rollback state; If the expected rotational speed direction is consistent with the current rotational speed direction, determine that the target vehicle is not in a rollback state.

[0007] Optionally, determining whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position includes: If the vehicle driving state is a forward state and the gear position is a forward gear position, determine that the expected rotational speed direction of the drive motor is a positive rotational speed direction; Determine whether the current rotational speed direction is a positive rotational speed direction; If the current rotational speed direction is a positive rotational speed direction, determine that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction; If the current rotational speed direction is a negative rotational speed direction, determine that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0008] Optionally, determining whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position includes: If the vehicle driving state is a reverse state and the gear position is a reverse gear position, determine that the expected rotational speed direction of the drive motor is a negative rotational speed direction; Determine whether the current rotational speed direction is a negative rotational speed direction; If the current rotational speed direction is a negative rotational speed direction, determine that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction; If the current rotational speed direction is a positive rotational speed direction, determine that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0009] Optionally, determining the slope holding assist output torque of the drive motor according to the current command torque and the current rotational speed value includes: Calculate the slope holding assist feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current rotational speed value; Determine the slope holding assist output torque of the drive motor according to the current command torque, the slope holding assist feedforward torque, and the proportional-integral control torque.

[0010] Optionally, calculating the slope-holding assist feedforward torque and the proportional-integral control torque of the drive motor according to the current rotational speed value respectively includes: Querying a preset gain coefficient corresponding to the current rotational speed value according to the current rotational speed value; Performing a multiplication operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the slope-holding assist feedforward torque; Querying the current proportional parameter and the current integral parameter of the drive motor according to the current rotational speed value and the target rotational speed value, where the target rotational speed value is the zero rotational speed value; Obtaining the proportional-integral control torque by using a preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter, and the current rotational speed value.

[0011] Optionally, determining the slope-holding assist output torque of the drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque includes: Performing a superposition operation on the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque; Performing an assignment limit process on the superposition torque to obtain the slope-holding assist output torque of the drive motor.

[0012] Optionally, controlling the torque of the drive motor to change from the current command torque to the slope-holding assist output torque and maintaining zero rotational speed includes: Controlling the torque of the drive motor to gradually transition from the current command torque to the slope-holding assist output torque according to a preset torque step value and maintaining zero rotational speed.

[0013] Optionally, controlling the torque of the drive motor to change from the slope-holding assist output torque to the current command torque includes: Calculating a torque difference according to the slope-holding assist output torque to the current command torque; Querying a target torque step value according to the torque difference; Controlling the torque of the drive motor to gradually change from the slope-holding assist output torque to the current command torque according to the target torque step value.

[0014] In a second aspect, an embodiment of the present application provides a control device, including: a processor and a storage medium, where the processor is communicatively connected to the storage medium through a bus, the storage medium stores program instructions executable by the processor, and the processor calls the program stored in the storage medium to execute the steps of the slope-holding assist control method according to any one of the first aspects.

[0015] Compared with the prior art, the present application has the following beneficial effects: The present application provides a slope-holding assist control method, device and equipment. The method determines whether the target vehicle is in a slope-sliding state according to the current state of the target vehicle; if the target vehicle is in a slope-sliding state, it enters the slope-holding assist state, and obtains the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle; the current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when in the slope-sliding state; determines the slope-holding assist output torque of the drive motor according to the current command torque and the current rotational speed value; controls the torque of the drive motor to change from the current command torque to the slope-holding assist output torque and maintains zero rotational speed; after entering the slope-holding assist state, if it is detected that the target vehicle meets the preset exit conditions of the slope-holding assist state, controls the torque of the drive motor to change from the slope-holding assist output torque to the current command torque. Thus, by jointly controlling the drive motor with the current command torque and the slope-holding assist output torque, slope-holding assist is realized, there is no slope-sliding, high sensitivity, short slope-sliding distance, the cost of the whole vehicle is reduced, and it is applicable to various types of vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of a vehicle slope-holding assist control system provided by an embodiment of the present application; Figure 2 It is a schematic flow diagram of a slope-holding assist control method provided by an embodiment of the present application; Figure 3 It is a schematic flow diagram of a method for determining whether the target vehicle is in a slope-sliding state according to the current state of the target vehicle provided by an embodiment of the present application; Figure 4 It is a schematic flow diagram of a method for determining whether the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent according to the vehicle driving state and gear provided by an embodiment of the present application; Figure 5 It is a schematic flow diagram of another method for determining whether the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent according to the vehicle driving state and gear provided by an embodiment of the present application; Figure 6 It is a schematic flow diagram of a method for determining the slope-holding assist output torque of the drive motor according to the current command torque and the current rotational speed value provided by an embodiment of the present application; Figure 7 The embodiments of the present application further provide a schematic flowchart of a method for calculating the slope-holding assist feedforward torque and the proportional-integral control torque of a drive motor according to the current rotational speed value; Figure 8 The embodiments of the present application further provide a schematic flowchart of a method for determining the slope-holding assist output torque of a drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque; Figure 9 The embodiments of the present application further provide a schematic flowchart of a method for controlling the torque of a drive motor to change from the slope-holding assist output torque to the current command torque; Figure 10 The embodiments of the present application provide a schematic diagram of a slope-holding assist control device; Figure 11 The embodiments of the present application provide a schematic diagram of an electronic device.

[0018] Icons: 1 - control device, 2 - vehicle controller, 3 - drive motor, 1001 - first determination module, 1002 - acquisition module, 1003 - second determination module, 1004 - first control module, 1005 - second control module, 1101 - processor, 1102 - storage medium. Detailed Embodiments

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. The components of the embodiments of the present application described and illustrated herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0021] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0022] In addition, terms such as "first" and "second" are used only for descriptive distinction and should not be construed as indicating or implying relative importance.

[0023] It should be noted that, without conflict, the features in the embodiments of the present invention can be combined with each other.

[0024] The following first explains a vehicle slope-holding assist control system provided by an embodiment of the present application through specific examples.

[0025] Figure 1 It is a schematic diagram of a vehicle slope-holding assist control system provided by an embodiment of the present application. As Figure 1 shown, the vehicle slope-holding assist control system at least includes: a control device 1, the control device 1 is connected to a vehicle controller 2 and a drive motor 3, and the control device 1 is used to execute a slope-holding assist control method provided by the present application.

[0026] In addition, in another embodiment of the present application, the present application embodiment also provides a vehicle, which at least includes: Figure 1 The vehicle slope-holding assist control system corresponding to the embodiment.

[0027] The following explains a slope-holding assist control method provided by the present application through specific examples. Figure 2 It is a schematic flowchart of a slope-holding assist control method provided by an embodiment of the present application. The execution subject of this method can be a control device, and this control device can be a device with computing and processing functions, such as a desktop computer, a laptop computer, etc. As Figure 2 shown, this method includes: S101. Determine whether the target vehicle is in a slope-sliding state according to the current state of the target vehicle.

[0028] Specifically, if the expected traveling direction of the vehicle is forward and the actual traveling direction of the vehicle is also forward, it is determined that the target vehicle is not in a slope-sliding state. If the expected traveling direction of the vehicle is reverse and the actual traveling direction of the vehicle is also reverse, it is determined that the target vehicle is not in a slope-sliding state.

[0029] If the expected traveling direction of the vehicle is forward and the actual traveling direction of the vehicle is reverse, it is determined that the target vehicle is in a slope-sliding state. If the expected traveling direction of the vehicle is reverse and the actual traveling direction of the vehicle is forward, it is determined that the target vehicle is in a slope-sliding state.

[0030] S102. If the target vehicle is in a slope-sliding state, enter the slope-holding assist state, and obtain the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle.

[0031] The current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when in the slope-sliding state.

[0032] For example, when the driver releases the brake pedal or steps on the accelerator pedal to start on a slope, the vehicle control unit will send a command torque to the motor. When it is determined that the vehicle is in a backward rolling state, the motor latches the current command torque, which is used to improve the response speed of the slope holding control.

[0033] S103. Determine the slope holding assist output torque of the drive motor according to the current command torque and the current rotational speed value.

[0034] If the current command torque is used to control the drive motor, it can be used to control the target vehicle, but there may be situations such as vehicle rolling backward. Therefore, the slope holding assist output torque is calculated using the current command torque and the current rotational speed value. The slope holding assist output torque can be used to superimpose and control the drive motor in the slope holding state, effectively preventing the target vehicle from rolling backward.

[0035] S104. Control the torque of the drive motor to change from the current command torque to the slope holding assist output torque and maintain zero rotational speed.

[0036] Changing from the current command torque to the slope holding assist output torque and maintaining zero rotational speed of the drive motor. In an actual scenario, zero rotational speed of the motor indicates that the vehicle is in a stopped state, thus effectively controlling the phenomenon of the target vehicle rolling backward.

[0037] S105. After entering the slope holding assist state, if it is detected that the target vehicle meets the preset exit conditions for the slope holding assist state, then control the torque of the drive motor to change from the slope holding assist output torque to the current command torque.

[0038] Among them, the preset exit conditions for the slope holding assist state are: slope holding state timeout, the driver steps on the brake pedal, the current command torque is greater than the slope holding assist output torque, etc. When the preset exit conditions for the slope holding assist state are met, it indicates that the target vehicle no longer requires slope holding assist at present.

[0039] Thus, by jointly controlling the drive motor with the current command torque and the slope holding assist output torque, slope holding assist is achieved, there is no rolling backward, there is no need for the vehicle's uphill assist system to assist, the slope holding torque fluctuation is small, it is less affected by vehicle weight and road slope, the sensitivity is high, the rolling backward distance is short, and the cost of the whole vehicle is reduced.

[0040] In summary, in this embodiment, according to the current state of the target vehicle, it is determined whether the target vehicle is in a rollback state; if the target vehicle is in a rollback state, it enters the slope holding assist state, and obtains the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle; the current command torque is the command torque sent by the vehicle control unit of the target vehicle to the drive motor when in the rollback state; according to the current command torque and the current rotational speed value, the slope holding assist output torque of the drive motor is determined; the torque of the drive motor is controlled to change from the current command torque to the slope holding assist output torque, and the zero rotational speed is maintained; after entering the slope holding assist state, if it is detected that the target vehicle meets the preset exit conditions of the slope holding assist state, the torque of the drive motor is controlled to change from the slope holding assist output torque to the current command torque. Thus, by jointly controlling the drive motor with the current command torque and the slope holding assist output torque, slope holding assist is realized, there is no rollback, the sensitivity is high, the rollback distance is short, the cost of the whole vehicle is reduced, and it is applicable to various types of vehicles.

[0041] In another embodiment of the present application, the present application embodiment also provides a method for determining whether a target vehicle is in a rollback state according to the current state of the target vehicle. Figure 3 It is a schematic flow chart of a method for determining whether a target vehicle is in a rollback state according to the current state of the target vehicle provided by an embodiment of the present application. As Figure 3 shown, the current state of the target vehicle includes: the vehicle driving state, the gear position, and the current rotational speed direction of the drive motor; determining whether the target vehicle is in a rollback state according to the current state of the target vehicle in S101 includes: S201. According to the vehicle driving state and the gear position, it is determined whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction.

[0042] The expected rotational speed is the rotational speed that the driver expects to reach after operating the vehicle, and the current rotational speed is the actual rotational speed of the motor. The expected rotational speed direction represents the expected traveling direction of the vehicle, and the current rotational speed direction represents the actual traveling direction of the vehicle.

[0043] S202. If the expected rotational speed direction is not consistent with the current rotational speed direction, it is determined that the target vehicle is in a rollback state.

[0044] If the expected rotational speed direction is not consistent with the current rotational speed direction. Then it is possible that the expected traveling direction of the vehicle is forward, but the actual traveling direction of the vehicle is backward. It is also possible that the expected traveling direction of the vehicle is backward, but the actual traveling direction of the vehicle is forward. Then it is determined that the target vehicle is in a rollback state.

[0045] S203. If the expected rotational speed direction is consistent with the current rotational speed direction, it is determined that the target vehicle is not in a rollback state.

[0046] If the desired rotation speed direction is the same as the current rotation speed direction, it is possible that the desired travel direction of the vehicle is forward and the actual travel direction of the vehicle is also forward. It is also possible that the desired travel direction of the vehicle is reverse and the actual travel direction of the vehicle is also reverse. Then it is determined that the target vehicle is not in a rolling-back state.

[0047] In summary, in this embodiment, according to the vehicle driving state and gear position, it is determined whether the desired rotation speed direction of the drive motor is the same as the current rotation speed direction; if the desired rotation speed direction is not the same as the current rotation speed direction, it is determined that the target vehicle is in a rolling-back state; if the desired rotation speed direction is the same as the current rotation speed direction, it is determined that the target vehicle is not in a rolling-back state. Thus, it is accurately determined whether the target vehicle is rolling back.

[0048] In another embodiment of the present application, the present application embodiment also provides a method for determining whether the desired rotation speed direction of the drive motor is the same as the current rotation speed direction according to the vehicle driving state and gear position. Figure 4 It is a schematic flow chart of a method for determining whether the desired rotation speed direction of the drive motor is the same as the current rotation speed direction according to the vehicle driving state and gear position provided by the present application embodiment. As Figure 4 shown, determining whether the desired rotation speed direction of the drive motor is the same as the current rotation speed direction according to the vehicle driving state and gear position in S201 includes: S301. If the vehicle driving state is the forward state and the gear position is the forward gear position, it is determined that the desired rotation speed direction of the drive motor is the positive rotation speed direction.

[0049] When the vehicle driving state is the forward state and the gear position is the forward gear position, it indicates that the driver expects to control the vehicle to move forward, which can be expressed at the motor level as: the desired rotation speed direction of the drive motor is the positive rotation speed direction.

[0050] S302. Determine whether the current rotation speed direction is the positive rotation speed direction.

[0051] The desired rotation speed in the previous step is the rotation speed that the driver expects to reach after controlling the vehicle, but the actual rotation speed does not necessarily match the desired rotation speed. Therefore, the real-time current rotation speed of the motor is obtained and the current rotation speed direction is judged.

[0052] S303. If the current rotation speed direction is the positive rotation speed direction, it is determined that the desired rotation speed direction of the drive motor is the same as the current rotation speed direction.

[0053] Since both the desired rotation speed direction and the current rotation speed direction are the positive rotation speed direction, the two rotation speed directions are the same.

[0054] S304. If the current rotation speed direction is the negative rotation speed direction, it is determined that the desired rotation speed direction of the drive motor is not the same as the current rotation speed direction.

[0055] If the expected rotational speed direction is the positive rotational speed direction and the current rotational speed direction is the negative rotational speed direction, then the rotational speed directions of the two are inconsistent.

[0056] In summary, in this embodiment, if the vehicle driving state is the forward state and the gear is the forward gear, then it is determined that the expected rotational speed direction of the drive motor is the positive rotational speed direction; it is determined whether the current rotational speed direction is the positive rotational speed direction; if the current rotational speed direction is the positive rotational speed direction, then it is determined that the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent; if the current rotational speed direction is the negative rotational speed direction, then it is determined that the expected rotational speed direction and the current rotational speed direction of the drive motor are inconsistent. Thus, it is accurately determined whether the rotational speed directions of the motor are consistent.

[0057] In another embodiment of the present application, the present application embodiment also provides another method for determining whether the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent according to the vehicle driving state and the gear. Figure 5 The flowchart of another method for determining whether the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent according to the vehicle driving state and the gear is provided for the embodiment of the present application. As Figure 5 shown, in S201, determining whether the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent according to the vehicle driving state and the gear includes: S401. If the vehicle driving state is the reverse state and the gear is the reverse gear, then it is determined that the expected rotational speed direction of the drive motor is the negative rotational speed direction.

[0058] If the vehicle driving state is the reverse state and the gear is the reverse gear, it indicates that the driver expects to control the vehicle to reverse, which can be represented at the motor level as: the expected rotational speed direction of the drive motor is the negative rotational speed direction.

[0059] S402. Determine whether the current rotational speed direction is the negative rotational speed direction.

[0060] The expected rotational speed in the previous step is the rotational speed that the driver expects to reach after controlling the vehicle, but the actual rotational speed does not necessarily match the expected rotational speed. Therefore, the real-time current rotational speed of the motor is obtained and the current rotational speed direction is judged.

[0061] S403. If the current rotational speed direction is the negative rotational speed direction, then it is determined that the expected rotational speed direction and the current rotational speed direction of the drive motor are consistent.

[0062] Since both the expected rotational speed direction and the current rotational speed direction are the negative rotational speed direction, the rotational speed directions of the two are consistent.

[0063] S404. If the current rotational speed direction is the positive rotational speed direction, then it is determined that the expected rotational speed direction and the current rotational speed direction of the drive motor are inconsistent.

[0064] If the desired rotational speed direction is the negative rotational speed direction and the current rotational speed direction is the positive rotational speed direction, then the rotational speed directions of the two are inconsistent.

[0065] In summary, in this embodiment, if the vehicle driving state is in reverse and the gear is in reverse gear, then determine that the desired rotational speed direction of the drive motor is the negative rotational speed direction; determine whether the current rotational speed direction is the negative rotational speed direction; if the current rotational speed direction is the negative rotational speed direction, then determine that the desired rotational speed direction and the current rotational speed direction of the drive motor are consistent; if the current rotational speed direction is the positive rotational speed direction, then determine that the desired rotational speed direction and the current rotational speed direction of the drive motor are inconsistent. Thus, accurately determine whether the rotational speed directions of the motor are consistent.

[0066] In another embodiment of the present application, the embodiment of the present application also provides a method for determining the slope-holding auxiliary output torque of a drive motor according to the current command torque and the current rotational speed value. Figure 6 It is a schematic flowchart of a method for determining the slope-holding auxiliary output torque of a drive motor according to the current command torque and the current rotational speed value provided by the embodiment of the present application. As Figure 6 shown, in S103, determining the slope-holding auxiliary output torque of the drive motor according to the current command torque and the current rotational speed value includes: S501. Calculate the slope-holding auxiliary feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current rotational speed value.

[0067] During the actual slope-holding driving of the target vehicle, the magnitude of the rotational speed of the motor that slips backward is different according to different slopes and the total vehicle load. Therefore, calculate the slope-holding auxiliary feedforward torque and the proportional-integral control torque of the drive motor based on the current rotational speed value. The obtained torque can make this method applicable to different slopes and vehicle loads.

[0068] S502. Determine the slope-holding auxiliary output torque of the drive motor according to the current command torque, the slope-holding auxiliary feedforward torque, and the proportional-integral control torque.

[0069] Control the drive motor jointly according to the current command torque, the slope-holding auxiliary feedforward torque, and the proportional-integral control torque, so that the drive motor realizes slope-holding assistance.

[0070] In summary, in this embodiment, calculate the slope-holding auxiliary feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current rotational speed value; determine the slope-holding auxiliary output torque of the drive motor according to the current command torque, the slope-holding auxiliary feedforward torque, and the proportional-integral control torque. Thus, accurately determine the slope-holding auxiliary output torque of the drive motor.

[0071] In another embodiment of the present application, the embodiment of the present application also provides a method for calculating the slope-holding auxiliary feedforward torque and the proportional-integral control torque of a drive motor respectively according to the current rotational speed value. Figure 7The present application embodiment also provides a flowchart of a method for calculating the slope-holding assist feedforward torque and the proportional-integral control torque of a drive motor according to the current rotational speed value. As Figure 7 shown, calculating the slope-holding assist feedforward torque and the proportional-integral control torque of the drive motor according to the current rotational speed value in S501 includes: S601. Query the preset gain coefficient corresponding to the current rotational speed value according to the current rotational speed value.

[0072] Among them, in the preset gain coefficient table, each rotational speed value corresponds to a gain coefficient. According to the current rotational speed value, the corresponding gain coefficient can be queried.

[0073] S602. Perform a multiplication operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the slope-holding assist feedforward torque.

[0074] Among them, the preset external characteristic torque of the drive motor is the maximum power in the power curve of the drive motor.

[0075] S603. Query the current proportional parameter and the current integral parameter of the drive motor according to the current rotational speed value and the target rotational speed value, and the target rotational speed value is the zero rotational speed value.

[0076] Among them, in the preset proportional-integral control table, each set of current rotational speed value and target rotational speed value corresponds to a set of proportional parameter and integral parameter. In the preset proportional-integral control table, input the current rotational speed value and the target rotational speed value, and the current proportional parameter and the current integral parameter can be obtained.

[0077] S604. Obtain the proportional-integral control torque by using the preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter, and the current rotational speed value.

[0078] Among them, the preset proportional-integral algorithm is an existing proportional-integral algorithm, which is not limited here.

[0079] In summary, in this embodiment, according to the current rotational speed value, query the preset gain coefficient corresponding to the current rotational speed value; perform a multiplication operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the slope-holding assist feedforward torque; query the current proportional parameter and the current integral parameter of the drive motor according to the current rotational speed value and the target rotational speed value, and the target rotational speed value is the zero rotational speed value; obtain the proportional-integral control torque by using the preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter, and the current rotational speed value. Thus, the slope-holding assist feedforward torque and the proportional-integral control torque of the drive motor are accurately calculated.

[0080] In another embodiment of the present application, the embodiment of the present application further provides a method for determining the slope-holding assist output torque of a drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque. Figure 8 The following is a schematic flowchart of a method for determining the slope-holding assist output torque of a drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque provided by the embodiment of the present application. As Figure 8 shown, in S502, determining the slope-holding assist output torque of the drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque includes: S701. Perform a superposition operation on the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque.

[0081] The current command torque represents the actual control requirement, and the slope-holding assist feedforward torque and the proportional-integral control torque implement the slope-holding assist. Adding the three together can achieve no rollback after slope-holding start.

[0082] S702. Perform an assignment limit process on the superposition torque to obtain the slope-holding assist output torque of the drive motor.

[0083] For the drive motor to implement slope-holding assist control, an assignment limit process is pre-performed on the superposition torque.

[0084] In summary, in this embodiment, a superposition operation is performed on the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque; an assignment limit process is performed on the superposition torque to obtain the slope-holding assist output torque of the drive motor. Thus, no rollback occurs after slope-holding start.

[0085] In another embodiment of the present application, in S104, controlling the torque of the drive motor to change from the current command torque to the slope-holding assist output torque and maintaining zero speed includes: According to a preset torque step value, control the torque of the drive motor to gradually transition from the current command torque to the slope-holding assist output torque and maintain zero speed.

[0086] The purpose of the torque of the drive motor becoming the slope-holding assist output torque is to prevent the vehicle from rolling back during slope-holding start. And rolling back occurs in an instant. Therefore, the torque control should be fast enough so that the vehicle can start successfully without rolling back quickly, improving the user experience. According to the preset torque step value, fast torque control is achieved. Among them, the preset torque step value is a value preset by the user, and there is no limitation here.

[0087] In summary, in this embodiment, according to the preset torque step value, the torque of the drive motor is controlled to gradually transition from the current command torque to the hill-hold assist output torque, and the zero speed is maintained. Thus, rapid torque control is achieved, enhancing the user experience.

[0088] In another embodiment of the present application, the present application embodiment also provides a method for controlling the torque of the drive motor to change from the hill-hold assist output torque to the current command torque. Figure 9 The present application embodiment also provides a schematic flowchart of a method for controlling the torque of the drive motor to change from the hill-hold assist output torque to the current command torque. As Figure 9 shown, in S105, controlling the torque of the drive motor to change from the hill-hold assist output torque to the current command torque includes: S801. Calculate the torque difference according to the hill-hold assist output torque to the current command torque.

[0089] To facilitate the change from the hill-hold assist state to the normal vehicle desired traveling state, first calculate the torque difference for control based on the torque difference.

[0090] S802. Query the target torque step value according to the torque difference.

[0091] If the torque quickly recovers from the hill-hold assist output torque to the current command torque, it will cause the vehicle to jerk, resulting in a poor experience for the driver and passengers. Therefore, the process of quickly recovering from the hill-hold assist output torque to the current command torque can be carried out slowly. According to the torque difference, query the torque step value corresponding to the torque difference in the preset torque step value table.

[0092] Among them, in the preset torque step value table, each torque difference corresponds to a torque step value.

[0093] For example, the larger the torque difference, the smaller the torque step value.

[0094] S803. Control the torque of the drive motor to gradually change from the hill-hold assist output torque to the current command torque according to the target torque step value.

[0095] Controlling the torque change according to the target torque step value makes the torque change slower. Thus, smooth torque transition is achieved during the transition, avoiding obvious jerks and enhancing the user experience.

[0096] In summary, in this embodiment, calculate the torque difference according to the hill-hold assist output torque to the current command torque; query the target torque step value according to the torque difference; control the torque of the drive motor to gradually change from the hill-hold assist output torque to the current command torque according to the target torque step value. Thus, smooth torque transition is achieved during the transition, avoiding obvious jerks and enhancing the user experience.

[0097] The following describes the hill-holding assist control device, server, storage medium, etc. provided by the present application for execution. For the specific implementation process and technical effects, please refer to the above, and will not be elaborated below.

[0098] Figure 10 It is a schematic diagram of a hill-holding assist control device provided by an embodiment of the present application. As Figure 10 shown, the device includes: A first determination module 1001, configured to determine whether the target vehicle is in a rolling-back state according to the current state of the target vehicle.

[0099] An acquisition module 1002, configured to enter the hill-holding assist state if the target vehicle is in a rolling-back state, and acquire the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle; the current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when in the rolling-back state.

[0100] A second determination module 1003, configured to determine the hill-holding assist output torque of the drive motor according to the current command torque and the current rotational speed value.

[0101] A first control module 1004, configured to control the torque of the drive motor to change from the current command torque to the hill-holding assist output torque and maintain zero rotational speed.

[0102] A second control module 1005, configured to, after entering the hill-holding assist state, if it is detected that the target vehicle meets the preset exit condition of the hill-holding assist state, control the torque of the drive motor to change from the hill-holding assist output torque to the current command torque.

[0103] Further, the first determination module 1001 is specifically configured that the current state of the target vehicle includes: the vehicle driving state, the gear position, and the current rotational speed direction of the drive motor; determine whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position; if the expected rotational speed direction is inconsistent with the current rotational speed direction, determine that the target vehicle is in a rolling-back state; if the expected rotational speed direction is consistent with the current rotational speed direction, determine that the target vehicle is not in a rolling-back state.

[0104] Further, the first determination module 1001 is specifically further configured to if the vehicle driving state is the forward state and the gear position is the forward gear position, determine that the expected rotational speed direction of the drive motor is the positive rotational speed direction; determine whether the current rotational speed direction is the positive rotational speed direction; if the current rotational speed direction is the positive rotational speed direction, determine that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction; if the current rotational speed direction is the negative rotational speed direction, determine that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0105] Further, the first determination module 1001 is specifically further configured to, if the vehicle driving state is a reverse state and the gear is in the reverse gear, determine that the desired rotational speed direction of the drive motor is the negative rotational speed direction; determine whether the current rotational speed direction is the negative rotational speed direction; if the current rotational speed direction is the negative rotational speed direction, determine that the desired rotational speed direction and the current rotational speed direction of the drive motor are consistent; if the current rotational speed direction is the positive rotational speed direction, determine that the desired rotational speed direction and the current rotational speed direction of the drive motor are inconsistent.

[0106] Further, the second determination module 1003 is specifically configured to calculate the slope holding assist feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current rotational speed value; determine the slope holding assist output torque of the drive motor according to the current command torque, the slope holding assist feedforward torque and the proportional-integral control torque.

[0107] Further, the second determination module 1003 is specifically further configured to query the preset gain coefficient corresponding to the current rotational speed value according to the current rotational speed value; perform a multiplication operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the slope holding assist feedforward torque; query the current proportional parameter and the current integral parameter of the drive motor according to the current rotational speed value and the target rotational speed value, and the target rotational speed value is the zero rotational speed value; use the preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter and the current rotational speed value to obtain the proportional-integral control torque.

[0108] Further, the second determination module 1003 is specifically further configured to perform a superposition operation on the current command torque, the slope holding assist feedforward torque and the proportional-integral control torque to obtain a superposition torque; perform an assignment limit process on the superposition torque to obtain the slope holding assist output torque of the drive motor.

[0109] Further, the first control module 1004 is specifically configured to control the torque of the drive motor to gradually transition from the current command torque to the slope holding assist output torque according to the preset torque step value and maintain zero rotational speed.

[0110] Further, the second control module 1005 is specifically configured to calculate the torque difference according to the slope holding assist output torque to the current command torque; query the target torque step value according to the torque difference; control the torque of the drive motor to gradually change from the slope holding assist output torque to the current command torque according to the target torque step value.

[0111] Figure 11 The figure is a schematic diagram of an electronic device provided by an embodiment of the present application, and the electronic device may be a device with computing and processing capabilities.

[0112] The electronic device includes: a processor 1101 and a storage medium 1102. The processor 1101 and the storage medium 1102 are connected through a bus.

[0113] The storage medium 1102 is used to store a program, and the processor 1101 calls the program stored in the storage medium 1102 to execute the above method embodiments. The specific implementation manners and technical effects are similar and will not be elaborated here.

[0114] Optionally, the present invention further provides a storage medium including a program, which is used to execute the above method embodiments when being executed by a processor. In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division manners in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0115] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0116] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit exists physically alone, or two or more units are integrated in one unit. The above integrated units can be implemented in the form of hardware, or in the form of hardware plus software functional units.

[0117] The above integrated units implemented in the form of software functional units can be stored in a storage medium. The above software functional units are stored in a storage medium and include several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to execute some steps of the methods described in each embodiment of the present invention. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (English: Read-Only Memory, abbreviated as: ROM), a random access memory (English: Random Access Memory, abbreviated as: RAM), a magnetic disk, or an optical disc that can store program codes.

Claims

1. A slope holding assist control method, characterized in that, The method includes: Determining whether the target vehicle is in a rollback state according to the current state of the target vehicle; If the target vehicle is in a rollback state, entering a hill-hold assist state, and obtaining the current command torque of the target vehicle and the current rotational speed value of the drive motor on the target vehicle; the current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when in the rollback state; Determining the hill-hold assist output torque of the drive motor according to the current command torque and the current rotational speed value; Controlling the torque of the drive motor to change from the current command torque to the hill-hold assist output torque and maintaining zero rotational speed; After entering the hill-hold assist state, if it is detected that the target vehicle meets the preset exit condition of the hill-hold assist state, controlling the torque of the drive motor to change from the hill-hold assist output torque to the current command torque.

2. The method according to claim 1, wherein The current state of the target vehicle includes: the vehicle driving state, the gear position, and the current rotational speed direction of the drive motor; determining whether the target vehicle is in a rollback state according to the current state of the target vehicle includes: Determining whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position; If the expected rotational speed direction is inconsistent with the current rotational speed direction, determining that the target vehicle is in a rollback state; If the expected rotational speed direction is consistent with the current rotational speed direction, determining that the target vehicle is not in a rollback state.

3. The method according to claim 2, wherein Determining whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position includes: If the vehicle driving state is the forward state and the gear position is the forward gear position, determining that the expected rotational speed direction of the drive motor is the positive rotational speed direction; Determining whether the current rotational speed direction is the positive rotational speed direction; If the current rotational speed direction is the positive rotational speed direction, determining that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction; If the current rotational speed direction is the negative rotational speed direction, determining that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

4. The method according to claim 2, wherein Determining whether the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and the gear position includes: If the vehicle driving state is the reverse state and the gear position is the reverse gear position, determining that the expected rotational speed direction of the drive motor is the negative rotational speed direction; Determining whether the current rotational speed direction is the negative rotational speed direction; If the current rotational speed direction is the negative rotational speed direction, determining that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction; If the current rotational speed direction is the positive rotational speed direction, determining that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

5. The method according to claim 1, wherein Determining the hill-hold assist output torque of the drive motor according to the current command torque and the current rotational speed value includes: Calculating the hill-hold assist feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current rotational speed value; Determine the slope-holding assist output torque of the drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque.

6. The method according to claim 5, characterized in that, The calculating of the slope-holding assist feedforward torque and the proportional-integral control torque of the drive motor respectively according to the current speed value includes: Query the preset gain coefficient corresponding to the current speed value according to the current speed value; Perform a multiplication operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the slope-holding assist feedforward torque; Query the current proportional parameter and the current integral parameter of the drive motor according to the current speed value and the target speed value, and the target speed value is the zero speed value; Obtain the proportional-integral control torque by using a preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter, and the current speed value.

7. The method according to claim 5, characterized in that The determining of the slope-holding assist output torque of the drive motor according to the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque includes: Perform a superposition operation on the current command torque, the slope-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque; Perform an assignment limit process on the superposition torque to obtain the slope-holding assist output torque of the drive motor.

8. The method according to claim 1, characterized in that, The controlling of the torque of the drive motor to change from the current command torque to the slope-holding assist output torque and maintain zero speed includes: Control the torque of the drive motor to gradually transition from the current command torque to the slope-holding assist output torque according to a preset torque step value and maintain zero speed.

9. The method according to claim 1, wherein The controlling of the torque of the drive motor to change from the slope-holding assist output torque to the current command torque includes: Calculate a torque difference according to the slope-holding assist output torque to the current command torque; Query a target torque step value according to the torque difference; Control the torque of the drive motor to gradually change from the slope-holding assist output torque to the current command torque according to the target torque step value.

10. A control device, characterized in that, Including: A processor and a storage medium. The processor is communicatively connected to the storage medium via a bus. The storage medium stores program instructions executable by the processor. The processor invokes the program stored in the storage medium to execute the steps of the slope-holding assist control method according to any one of claims 1 to 9.

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