Hill-holding assist control method, device and equipment

Abstract

The present application provides a hill-holding assist control method, device, and apparatus. The method determines whether the target vehicle is in a rolling hill state based on the current state of the target vehicle; if the target vehicle is in a rolling hill state, the method enters a hill-holding assist state and obtains the current command torque of the target vehicle and the current 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 the vehicle is in a rolling hill state; the hill-holding assist output torque of the drive motor is determined based on the current command torque and the current speed value; the torque of the drive motor is controlled to change from the current command torque to the hill-holding assist output torque, and the speed is maintained at zero; after entering the hill-holding assist state, if it is detected that the target vehicle meets the preset exit conditions of the hill-holding assist state, the torque of the drive motor is controlled to change from the hill-holding assist output torque to the current command torque. Thus, hill-holding assist is achieved without rolling hills, with high sensitivity and reduced vehicle cost.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle control technology, and in particular to a hill-holding assist control method, device and equipment. Background Art

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

[0003] For commercial vehicles, traditional fuel-powered vehicles generally utilize mechanical parking brakes or automatic parking systems (Auto Hold), which coordinate the transmission locking mechanism with the braking system to achieve hill parking. However, due to fundamental differences in their powertrain structure, pure electric vehicles are prone to reverse rolling when starting on a slope, posing a significant safety hazard. Currently, some pure electric vehicles use HAC (hill start assist) to prevent rolling, but this results in high vehicle cost and low reliability. Existing technologies are mostly designed for hill starting or holding on passenger cars, which are easy to implement with minimal vehicle mass variation. However, this approach is less suitable for commercial vehicles, where the vehicle load varies significantly. Summary of the Invention

[0004] The object of the present invention is to provide a hill-holding assist control method, device and equipment to address the above-mentioned deficiencies in the prior art, so as to solve the problems of poor applicability in the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a hill-hold assist control method, the method comprising:

[0007] Determining whether the target vehicle is in a sliding slope state according to the current state of the target vehicle;

[0008] If the target vehicle is in a rolling hill state, the vehicle enters a hill hold assist state and obtains the current command torque of the target vehicle and the current 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 the target vehicle is in a rolling hill state;

[0009] determining a hill-holding assist output torque of the drive motor according to the current command torque and the current speed value;

[0010] Controlling the torque of the drive motor to change from the current command torque to the hill-holding assist output torque while maintaining zero speed;

[0011] After entering the hill hold assist state, if it is detected that the target vehicle meets a preset exit condition of the hill hold assist state, the torque of the drive motor is controlled to change from the hill hold assist output torque to the current command torque.

[0012] Optionally, the current state of the target vehicle includes: a vehicle driving state, a gear position, and a current rotational speed direction of the drive motor; and determining whether the target vehicle is in a rolling slope state based on the current state of the target vehicle includes:

[0013] determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position;

[0014] If the desired rotational speed direction is inconsistent with the current rotational speed direction, determining that the target vehicle is in a rolling downhill state;

[0015] 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 rolling downhill state.

[0016] 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 gear position includes:

[0017] If the vehicle is in a forward state and the gear is in a forward gear, determining that the desired rotational speed direction of the drive motor is a positive rotational speed direction;

[0018] Determining whether the current rotational speed direction is a positive rotational speed direction;

[0019] If the current rotational speed direction is a positive rotational speed direction, determining that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction;

[0020] If the current rotational speed direction is a negative rotational speed direction, it is determined that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0021] 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 gear position includes:

[0022] If the vehicle is in a reverse state and the gear is in a reverse gear, determining that the desired rotational speed direction of the drive motor is a negative rotational speed direction;

[0023] Determining whether the current rotational speed direction is a negative rotational speed direction;

[0024] If the current rotational speed direction is a negative rotational speed direction, determining that the expected rotational speed direction of the drive motor is consistent with the current rotational speed direction;

[0025] If the current rotational speed direction is a positive rotational speed direction, it is determined that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0026] Optionally, determining the hill-holding assist output torque of the drive motor according to the current command torque and the current speed value includes:

[0027] Calculating the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor according to the current speed value;

[0028] The hill-holding assist output torque of the drive motor is determined according to the current command torque, the hill-holding assist feedforward torque and the proportional-integral control torque.

[0029] Optionally, the calculating, according to the current speed value, respectively the hill-holding assist feedforward torque and the proportional-integral control torque of the drive motor includes:

[0030] According to the current speed value, querying a preset gain coefficient corresponding to the current speed value;

[0031] Performing a product operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the hill-holding assist feedforward torque;

[0032] querying a current proportional parameter and a current integral parameter of the drive motor according to the current speed value and the target speed value, wherein the target speed value is a zero speed value;

[0033] The proportional-integral control torque is obtained by adopting a preset proportional-integral control algorithm according to the previous proportional parameter, the current integral parameter and the current speed value.

[0034] Optionally, determining the hill-holding assist output torque of the drive motor according to the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque includes:

[0035] performing a superposition operation on the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque;

[0036] The superimposed torque is subjected to assignment and restriction processing to obtain the hill-holding assist output torque of the drive motor.

[0037] Optionally, controlling the torque of the drive motor to change from the current command torque to the hill-holding assist output torque while maintaining zero speed includes:

[0038] According to a preset torque step value, the torque of the drive motor is controlled to gradually transition from the current command torque to the hill-holding assist output torque while maintaining zero speed.

[0039] Optionally, controlling the torque of the drive motor to change from the hill-holding assist output torque to the current command torque includes:

[0040] Calculating a torque difference according to the hill-holding assist output torque and the current command torque;

[0041] querying a target torque step value according to the torque difference;

[0042] According to the target torque step value, the torque of the drive motor is controlled to gradually change from the hill-holding assist output torque to the current command torque.

[0043] In a second aspect, an embodiment of the present application provides a control device, comprising: a processor and a storage medium, wherein the processor and the storage medium are communicatively connected via 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 hill-holding assist control method as described in any one of the first aspects.

[0044] Compared with the prior art, this application has the following beneficial effects:

[0045] The present application provides a hill-holding assist control method, device, and apparatus. The method determines whether the target vehicle is in a rolling hill state based on the current state of the target vehicle; if the target vehicle is in a rolling hill state, the method enters a hill-holding assist state and obtains the current command torque of the target vehicle and the current 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 the vehicle is in a rolling hill state; the hill-holding assist output torque of the drive motor is determined based on the current command torque and the current speed value; the torque of the drive motor is controlled to change from the current command torque to the hill-holding assist output torque, and the speed is maintained at zero; after entering the hill-holding assist state, if it is detected that the target vehicle meets the preset exit conditions of the hill-holding assist state, the torque of the drive motor is controlled to change from the hill-holding assist output torque to the current command torque. Thus, the drive motor is controlled by the current command torque and the hill-holding assist output torque to achieve hill-holding assist, without rolling hill, with high sensitivity and short rolling hill distance, thus reducing the cost of the vehicle and being applicable to various types of vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 A schematic diagram of a vehicle hill-holding assist control system provided in an embodiment of the present application;

[0048] Figure 2 A flowchart of a hill-holding assist control method provided in an embodiment of the present application;

[0049] Figure 3 A flowchart of a method for determining whether a target vehicle is in a rolling slope state based on the current state of the target vehicle provided in an embodiment of the present application;

[0050] Figure 4 The present application also provides a flowchart of a method for determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position;

[0051] Figure 5 The present application also provides a flowchart of another method for determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position;

[0052] Figure 6 The present application also provides a flowchart of a method for determining the hill-holding assist output torque of a drive motor according to the current command torque and the current speed value;

[0053] Figure 7 The embodiment of the present application also provides a flow chart of a method for respectively calculating the hill-holding assist feedforward torque and the proportional-integral control torque of the drive motor according to the current speed value;

[0054] Figure 8 The present invention also provides a flowchart of a method for determining the hill-holding assist output torque of a drive motor according to the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque.

[0055] Figure 9 The embodiment of the present application also provides a flow chart of a method for controlling the torque of the drive motor to change from the hill-holding assist output torque to the current command torque;

[0056] Figure 10 A schematic diagram of a hill-holding assist control device provided in an embodiment of the present application;

[0057] Figure 11 A schematic diagram of an electronic device provided in an embodiment of the present application.

[0058] Icon: 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 DESCRIPTION

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0060] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0061] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0062] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0063] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0064] The following first explains a vehicle hill-holding assist control system provided by an embodiment of the present application through a specific example.

[0065] Figure 1 This is a schematic diagram of a vehicle hill-holding assist control system provided in an embodiment of the present application. Figure 1 As shown, the vehicle hill-holding assist control system includes at least: a control device 1, the control device 1 is connected to the vehicle controller 2 and the drive motor 3, and the control device 1 is used to execute a hill-holding assist control method provided in this application.

[0066] In addition, in another embodiment of the present application, the embodiment of the present application further provides a vehicle, which at least includes: Figure 1 The vehicle hill-holding assist control system provided in the corresponding embodiment.

[0067] The following is an explanation of a hill-holding assist control method provided in this application through a specific example. Figure 2 This is a flow chart of a hill-holding assist control method provided by an embodiment of the present application. The execution subject of this method may be a control device, which may be a device with computing and processing functions, such as a desktop computer, a laptop computer, etc. Figure 2 As shown, the method includes:

[0068] S101. Determine whether the target vehicle is in a rolling downhill state based on the current state of the target vehicle.

[0069] Specifically, if the desired direction of travel of the vehicle is forward and the actual direction of travel of the vehicle is also forward, it is determined that the target vehicle is not in a sliding slope state. If the desired direction of travel of the vehicle is reverse and the actual direction of travel of the vehicle is also reverse, it is determined that the target vehicle is not in a sliding slope state.

[0070] If the desired direction of travel of the vehicle is forward and the actual direction of travel of the vehicle is also reverse, it is determined that the target vehicle is in a sliding state. If the desired direction of travel of the vehicle is reverse and the actual direction of travel of the vehicle is also forward, it is determined that the target vehicle is in a sliding state.

[0071] S102: If the target vehicle is in a rolling downhill state, the vehicle enters a hill-holding assist state and obtains a current command torque of the target vehicle and a current speed value of a drive motor on the target vehicle.

[0072] The current command torque is the command torque sent by the vehicle controller of the target vehicle to the drive motor when the target vehicle is in a slope state.

[0073] For example, when the driver releases the brake pedal or presses the accelerator to start on a slope, the vehicle controller sends a torque command to the motor. If the vehicle is determined to be in a backward roll state, the motor latches the current torque command, which is used to improve the response speed of the hill-holding control.

[0074] S103: Determine the hill-holding assist output torque of the drive motor according to the current command torque and the current speed value.

[0075] If the current command torque is used to control the drive motor, it can be used to control the target vehicle, but the vehicle may roll down the slope. Therefore, the current command torque and the current speed value are used to calculate the hill-holding assist output torque. The hill-holding assist output torque can be used to superimpose the control of the drive motor in the hill-holding state, effectively preventing the target vehicle from rolling down the slope.

[0076] S104 , controlling the torque of the drive motor to change from the current command torque to the hill-holding assist output torque, while maintaining zero speed.

[0077] The current command torque changes to the hill-holding assist output torque to maintain the drive motor at zero speed. In actual scenarios, zero motor speed indicates that the vehicle is in a stopped state, thereby effectively controlling the target vehicle's sliding downhill.

[0078] S105 . After entering the hill hold assist state, if it is detected that the target vehicle meets a preset exit condition of the hill hold assist state, the torque of the drive motor is controlled to change from the hill hold assist output torque to the current command torque.

[0079] The preset exit conditions for the Hill Hold Assist state include: Hill Hold timeout, the driver pressing the brake pedal, the current command torque being greater than the Hill Hold Assist output torque, etc. When the preset exit conditions for the Hill Hold Assist state are met, it indicates that the target vehicle no longer needs Hill Hold Assist.

[0080] Therefore, the drive motor is controlled jointly by the current command torque and the hill-holding assist output torque to achieve hill-holding assist, without sliding down the slope. There is no need for assistance from the vehicle's hill-holding assist system, the hill-holding torque has small fluctuations, is less affected by vehicle weight and road slope, has high sensitivity, and has a short sliding distance, thus reducing the cost of the entire vehicle.

[0081] In summary, in this embodiment, based on the current state of the target vehicle, it is determined whether the target vehicle is in a rolling hill state. If the target vehicle is in a rolling hill state, the hill hold assist state is entered, and the current command torque of the target vehicle and the current speed value of the drive motor on the target vehicle are obtained. 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 hill state. The hill hold assist output torque of the drive motor is determined based on the current command torque and the current speed value. The torque of the drive motor is controlled to change from the current command torque to the hill hold assist output torque while maintaining zero 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, the torque of the drive motor is controlled to change from the hill hold assist output torque to the current command torque. Thus, by jointly controlling the drive motor through the current command torque and the hill hold assist output torque, the hill hold assist is achieved, preventing rolling hills, with high sensitivity and a short rolling hill distance, thus reducing the cost of the vehicle and being applicable to various types of vehicles.

[0082] In another embodiment of the present application, the embodiment of the present application also provides a method for determining whether the target vehicle is in a rolling slope state based on the current state of the target vehicle. Figure 3 A flow chart of a method for determining whether a target vehicle is in a rolling slope state according to the current state of the target vehicle is provided in an embodiment of the present application. Figure 3 As shown, the current state of the target vehicle includes: the vehicle driving state, the gear position, and the current speed direction of the drive motor; S101 determines whether the target vehicle is in a rolling slope state based on the current state of the target vehicle, including:

[0083] S201: Determine whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position.

[0084] The desired speed is the speed the driver wants to achieve after maneuvering the vehicle, while the current speed is the actual speed of the motor. The desired speed direction represents the desired direction of travel for the vehicle, while the current speed direction represents the actual direction of travel.

[0085] S202: If the expected rotational speed direction is inconsistent with the current rotational speed direction, it is determined that the target vehicle is in a rolling downhill state.

[0086] If the desired speed direction is inconsistent with the current speed direction, it is possible that the vehicle's desired direction of travel is forward, but the vehicle is actually moving in reverse. Alternatively, the desired direction of travel is reverse, but the vehicle is actually moving in forward direction. In this case, the target vehicle is determined to be rolling down a slope.

[0087] 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 rolling downhill state.

[0088] If the desired speed direction is consistent with the current speed direction, it is possible that the vehicle's desired direction of travel is forward, and the vehicle's actual direction of travel is also forward. Alternatively, it is possible that the vehicle's desired direction of travel is reverse, and the vehicle's actual direction of travel is also reverse. In this case, it is determined that the target vehicle is not rolling down a slope.

[0089] In summary, in this embodiment, based on the vehicle's driving state and gear position, a determination is made as to whether the desired and current rotational speed directions of the drive motor are consistent. If the desired and current rotational speed directions are inconsistent, the target vehicle is determined to be rolling downhill. If the desired and current rotational speed directions are consistent, the target vehicle is determined not to be rolling downhill. This allows for accurate determination of whether the target vehicle is rolling downhill.

[0090] In another embodiment of the present application, the embodiment of the present application further provides a method for determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position. Figure 4 The present application also provides a flowchart of a method for determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position. Figure 4 As shown, in S201, determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position includes:

[0091] S301: If the vehicle is in a forward state and the gear is in a forward gear, determine that the desired rotational speed direction of the drive motor is a positive rotational speed direction.

[0092] When the vehicle is in a forward driving state and the gear is in a forward gear, it indicates that the driver desires to control the vehicle to move forward. From the motor level, this can be expressed as: the desired speed direction of the drive motor is a positive speed direction.

[0093] S302: Determine whether the current rotational speed direction is a positive rotational speed direction.

[0094] The desired speed in the previous step is the speed the driver expects to achieve after maneuvering the vehicle, but the actual speed may not necessarily match the desired speed. Therefore, the current speed of the motor is obtained in real time and the current speed direction is determined.

[0095] S303: 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.

[0096] If the expected speed direction and the current speed direction are both positive, then the speed directions of the two are consistent.

[0097] S304: If the current rotational speed direction is a negative rotational speed direction, it is determined that the expected rotational speed direction of the drive motor is inconsistent with the current rotational speed direction.

[0098] If the expected speed direction is positive and the current speed direction is negative, the speed directions of the two are inconsistent.

[0099] In summary, in this embodiment, if the vehicle is in a forward state and the gear is in a forward gear, the desired rotational speed direction of the drive motor is determined to be a positive rotational speed direction; a determination is made as to whether the current rotational speed direction is a positive rotational speed direction; if the current rotational speed direction is a positive rotational speed direction, the desired rotational speed direction of the drive motor and the current rotational speed direction are determined to be consistent; if the current rotational speed direction is a negative rotational speed direction, the desired rotational speed direction of the drive motor and the current rotational speed direction are determined to be inconsistent. Thus, whether the motor rotational speed directions are consistent is accurately determined.

[0100] In another embodiment of the present application, the embodiment of the present application also provides another method for determining whether the expected speed direction of the drive motor is consistent with the current speed direction according to the vehicle driving state and gear position. Figure 5 The present application also provides a flowchart of another method for determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position. Figure 5 As shown, in S201, determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position includes:

[0101] S401: If the vehicle is in a reverse state and the gear is in a reverse gear, determine that the desired rotational speed direction of the drive motor is a negative rotational speed direction.

[0102] When the vehicle is in reverse and the gear is in reverse, it means that the driver wants to control the vehicle to reverse. From the motor level, it can be expressed as: the expected speed direction of the drive motor is in the negative speed direction.

[0103] S402: Determine whether the current rotational speed direction is a negative rotational speed direction.

[0104] The desired speed in the previous step is the speed the driver expects to achieve after maneuvering the vehicle, but the actual speed may not necessarily match the desired speed. Therefore, the current speed of the motor is obtained in real time and the current speed direction is determined.

[0105] S403: 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.

[0106] If the desired speed direction and the current speed direction are both negative, then the speed directions of the two are consistent.

[0107] S404: 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.

[0108] If the expected speed direction is negative and the current speed direction is positive, the speed directions of the two are inconsistent.

[0109] In summary, in this embodiment, if the vehicle is in reverse and the gear is in reverse, the desired rotational speed direction of the drive motor is determined to be negative; a determination is made as to whether the current rotational speed direction is negative; if the current rotational speed direction is negative, the desired rotational speed direction and the current rotational speed direction of the drive motor are determined to be consistent; if the current rotational speed direction is positive, the desired rotational speed direction and the current rotational speed direction of the drive motor are determined to be inconsistent. Thus, whether the motor rotational speed directions are consistent is accurately determined.

[0110] In another embodiment of the present application, the embodiment of the present application also provides a method for determining the hill-holding assist output torque of the drive motor according to the current command torque and the current speed value. Figure 6 The present application also provides a flowchart of a method for determining the hill-holding assist output torque of the drive motor according to the current command torque and the current speed value. Figure 6 As shown, in S103, the hill-holding assist output torque of the drive motor is determined according to the current command torque and the current speed value, including:

[0111] S501 : Calculate the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor according to the current speed value.

[0112] During the target vehicle's actual hill-holding process, the slipping motor speed varies depending on the slope and vehicle load. Therefore, the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor are calculated based on the current speed. The resulting torque allows this method to be adapted to varying slopes and vehicle loads.

[0113] S502 : Determine the hill-holding assist output torque of the drive motor according to the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque.

[0114] The drive motor is controlled jointly according to the current command torque, the hill-holding assist feedforward torque and the proportional-integral control torque, thereby enabling the drive motor to achieve hill-holding assist.

[0115] In summary, in this embodiment, the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor are calculated based on the current speed value. The hill-holding assist output torque of the drive motor is determined based on the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque. This allows the hill-holding assist output torque of the drive motor to be accurately determined.

[0116] In another embodiment of the present application, the embodiment of the present application further provides a method for respectively calculating the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor according to the current speed value. Figure 7 The present application also provides a flow chart of a method for calculating the hill-holding assist feedforward torque and proportional integral control torque of the drive motor according to the current speed value. Figure 7 As shown, in S501, the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor are calculated according to the current speed value, including:

[0117] S601: Query a preset gain coefficient corresponding to the current speed value according to the current speed value.

[0118] In the preset gain coefficient table, each speed value corresponds to a gain coefficient. The corresponding gain coefficient can be queried based on the current speed value.

[0119] S602 : Perform a product operation on the preset gain coefficient and the preset external characteristic torque of the driving motor to obtain a hill-holding assist feedforward torque.

[0120] The preset external characteristic torque of the drive motor is the maximum power in the power curve of the drive motor.

[0121] S603 : According to the current speed value and the target speed value, query the current proportional parameter and the current integral parameter of the drive motor, and the target speed value is a zero speed value.

[0122] In the preset proportional-integral control table, each set of current speed value and target speed value corresponds to a set of proportional parameters and integral parameters. In the preset proportional-integral control table, by inputting the current speed value and target speed value, the current proportional parameters and current integral parameters can be obtained.

[0123] S604 : According to the previous proportional parameter, the current integral parameter and the current speed value, a preset proportional integral control algorithm is used to obtain a proportional integral control torque.

[0124] The preset proportional integral algorithm is an existing proportional integral algorithm, which is not limited here.

[0125] In summary, in this embodiment, the preset gain coefficient corresponding to the current speed value is queried based on the current speed value; the preset gain coefficient is multiplied by the preset external characteristic torque of the drive motor to obtain the hill-holding assist feedforward torque; the current proportional parameter and current integral parameter of the drive motor are queried based on the current speed value and the target speed value, with the target speed value being zero speed; and the preset proportional-integral control algorithm is employed based on the forward proportional parameter, the current integral parameter, and the current speed value to obtain the proportional-integral control torque. Thus, the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor are accurately calculated.

[0126] In another embodiment of the present application, the embodiment of the present application also provides a method for determining the hill-holding assist output torque of the drive motor based on the current command torque, the hill-holding assist feedforward torque and the proportional-integral control torque. Figure 8 The present application also provides a flowchart of a method for determining the hill-holding assist output torque of the drive motor according to the current command torque, the hill-holding assist feedforward torque and the proportional-integral control torque. Figure 8 As shown, the step S502 determines the hill-holding assist output torque of the drive motor according to the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque, including:

[0127] S701 , performing a superposition operation on the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque.

[0128] The current command torque represents the actual control demand. The hill-holding assist feedforward torque and proportional-integral control torque realize the hill-holding assist. By adding the three together, the vehicle can be prevented from sliding down the hill after starting on the hill.

[0129] S702: Perform value assignment and restriction processing on the superimposed torque to obtain the hill-holding assist output torque of the drive motor.

[0130] In order to facilitate the drive motor to achieve hill-holding assist control, the superimposed torque is assigned and limited in advance.

[0131] In summary, in this embodiment, the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque are superimposed to obtain the superimposed torque. This superimposed torque is then assigned and constrained to obtain the hill-holding assist output torque for the drive motor. This prevents the vehicle from rolling downhill after starting on a hill.

[0132] In another embodiment of the present application, controlling the torque of the drive motor in S104 to change from the current command torque to the hill-holding assist output torque while maintaining zero speed includes:

[0133] 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-holding assist output torque while maintaining zero speed.

[0134] The drive motor's torque is converted into a hill-hold assist output torque to prevent the vehicle from rolling downhill during a hill-hold start. Since rolling downhill occurs in an instant, torque control must be fast enough to allow the vehicle to start quickly without rolling downhill, improving the user experience. Rapid torque control is achieved based on a preset torque step value. The preset torque step value is a user-defined value and is not a restriction.

[0135] In summary, in this embodiment, the torque of the drive motor is controlled to gradually transition from the current command torque to the hill-holding assist output torque based on the preset torque step value, while maintaining zero speed. This achieves rapid torque control and improves the user experience.

[0136] In another embodiment of the present application, the embodiment of the present application also provides a method for controlling the torque of the drive motor to change from the hill-holding assist output torque to the current command torque. Figure 9 The present application also provides a flowchart of a method for controlling the torque of the drive motor to change from the hill-holding assist output torque to the current command torque. Figure 9 As shown, the control of the torque of the drive motor in S105 changes from the hill-holding assist output torque to the current command torque, including:

[0137] S801. Calculate the torque difference between the hill-holding assist output torque and the current command torque.

[0138] In order to facilitate the transition from the hill-hold assist state to the normal desired vehicle travel state, the torque difference is first calculated so as to perform control based on the torque difference.

[0139] S802: Query the target torque step value according to the torque difference.

[0140] If the hill-hold assist output torque is quickly restored to the current command torque, the vehicle will jerk, resulting in a poor driver and passenger experience. Therefore, the process of quickly restoring the hill-hold assist output torque to the current command torque can be performed more slowly. Based on the torque difference, the torque step value corresponding to the torque difference is searched in the preset torque step value table.

[0141] Among them, in the preset torque step value table, each torque difference corresponds to a torque step value.

[0142] For example, the larger the torque difference, the smaller the torque step value.

[0143] S803 : According to the target torque step value, the torque of the drive motor is controlled to gradually change from the hill-holding assist output torque to the current command torque.

[0144] The torque change is controlled according to the target torque step value, making the torque change slower. This achieves a smooth torque transition during the transition, avoiding obvious jerks and improving the user experience.

[0145] In summary, this embodiment calculates the torque difference between the hill-hold assist output torque and the current command torque; uses this torque difference to query the target torque step value; and uses this target torque step value to gradually control the drive motor's torque from the hill-hold assist output torque to the current command torque. This ensures a smooth torque transition, avoiding noticeable jerks and improving the user experience.

[0146] The following describes the hill-holding assist control device, server, storage medium, etc. provided in this application for execution. The specific implementation process and technical effects are described above and will not be repeated below.

[0147] Figure 10 This is a schematic diagram of a hill-holding assist control device provided in an embodiment of the present application. Figure 10 As shown, the device includes:

[0148] The first determining module 1001 is configured to determine whether the target vehicle is in a rolling downhill state according to the current state of the target vehicle.

[0149] The acquisition module 1002 is used to enter the hill hold assist state if the target vehicle is in a rolling hill state, and obtain the current command torque of the target vehicle and the current 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 the target vehicle is in a rolling hill state.

[0150] The second determining module 1003 is configured to determine the hill-holding assist output torque of the driving motor according to the current command torque and the current speed value.

[0151] The first control module 1004 is configured to control the torque of the drive motor to change from the current command torque to the hill-holding assist output torque while maintaining zero speed.

[0152] The second control module 1005 is configured to control the torque of the drive motor to change from the hill hold assist output torque to the current command torque 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.

[0153] Furthermore, the first determination module 1001 is specifically used for the current state of the target vehicle including: the vehicle driving state, gear position and the current speed direction of the drive motor; according to the vehicle driving state and gear position, determining whether the expected speed direction and the current speed direction of the drive motor are consistent; if the expected speed direction is inconsistent with the current speed direction, determining that the target vehicle is in a rolling hill state; if the expected speed direction is consistent with the current speed direction, determining that the target vehicle is not in a rolling hill state.

[0154] Furthermore, the first determination module 1001 is specifically used to determine that the expected speed direction of the drive motor is a positive speed direction if the vehicle is in a forward state and the gear is in a forward gear; determine whether the current speed direction is a positive speed direction; if the current speed direction is a positive speed direction, determine that the expected speed direction of the drive motor is consistent with the current speed direction; if the current speed direction is a negative speed direction, determine that the expected speed direction of the drive motor is inconsistent with the current speed direction.

[0155] Furthermore, the first determination module 1001 is specifically used to determine that the expected speed direction of the drive motor is a negative speed direction if the vehicle is in a reverse state and the gear is in a reverse gear; determine whether the current speed direction is a negative speed direction; if the current speed direction is a negative speed direction, determine that the expected speed direction of the drive motor is consistent with the current speed direction; if the current speed direction is a positive speed direction, determine that the expected speed direction of the drive motor is inconsistent with the current speed direction.

[0156] Furthermore, the second determination module 1003 is specifically used to calculate the hill-holding assist feedforward torque and proportional-integral control torque of the drive motor according to the current speed value; and determine the hill-holding assist output torque of the drive motor according to the current command torque, the hill-holding assist feedforward torque and the proportional-integral control torque.

[0157] Furthermore, the second determination module 1003 is specifically used to query the preset gain coefficient corresponding to the current speed value according to the current speed value; perform a product operation on the preset gain coefficient and the preset external characteristic torque of the drive motor to obtain the hill-holding auxiliary 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 a zero speed value; and adopt a preset proportional-integral control algorithm according to the front proportional parameter, the current integral parameter and the current speed value to obtain the proportional-integral control torque.

[0158] Furthermore, the second determination module 1003 is further configured to perform a superposition operation on the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposed torque; and perform a value restriction process on the superposed torque to obtain the hill-holding assist output torque of the drive motor.

[0159] Furthermore, 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 hill-holding assist output torque according to a preset torque step value, while maintaining zero speed.

[0160] Furthermore, the second control module 1005 is specifically used to calculate the torque difference based on the hill-holding assist output torque to the current command torque; query the target torque step value based on the torque difference; and control the torque of the drive motor to gradually change from the hill-holding assist output torque to the current command torque based on the target torque step value.

[0161] Figure 11 A schematic diagram of an electronic device provided in an embodiment of the present application, which may be a device with computing and processing functions.

[0162] The electronic device includes: a processor 1101 and a storage medium 1102. The processor 1101 and the storage medium 1102 are connected via a bus.

[0163] The storage medium 1102 is used to store programs, and the processor 1101 calls the programs stored in the storage medium 1102 to execute the above method embodiment. The specific implementation methods and technical effects are similar and will not be repeated here.

[0164] Optionally, the present invention also provides a storage medium, including a program, which is used to execute the above-mentioned method embodiment when executed by a processor. In the 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 schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as 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 mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0165] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0166] In addition, the functional units in various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or hardware plus software functional units.

[0167] The aforementioned integrated unit implemented as a software functional unit can be stored in a storage medium. The software functional unit stored in a storage medium includes instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) or a processor to perform some of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

Claims

1. A hill-holding assist control method, characterized in that: The method comprises: Determining whether the target vehicle is in a sliding slope state according to the current state of the target vehicle; If the target vehicle is in a rolling hill state, the vehicle enters a hill hold assist state and obtains the current command torque of the target vehicle and the current 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 the target vehicle is in a rolling hill state; According to the current speed value, querying a preset gain coefficient corresponding to the current speed value; wherein each speed value corresponds to a gain coefficient; The hill-holding assist feedforward torque is obtained by multiplying the preset gain coefficient and the preset external characteristic torque of the drive motor; wherein the preset external characteristic torque is the maximum power in the power curve of the drive motor; querying a current proportional parameter and a current integral parameter of the drive motor according to the current speed value and the target speed value, wherein the target speed value is a zero speed value; According to the current proportional parameter, the current integral parameter and the current speed value, a preset proportional-integral control algorithm is used to obtain a proportional-integral control torque; performing a superposition operation on the current command torque, the hill-holding assist feedforward torque, and the proportional-integral control torque to obtain a superposition torque; performing a value assignment and restriction process on the superimposed torque to obtain a hill-holding assist output torque of the drive motor; Controlling the torque of the drive motor to change from the current command torque to the hill-holding assist output torque while maintaining zero speed; After entering the hill hold assist state, if it is detected that the target vehicle meets a preset exit condition of the hill hold assist state, the torque of the drive motor is controlled to change from the hill hold assist output torque to the current command torque.

2. The method according to claim 1, characterized in that The current state of the target vehicle includes: the vehicle driving state, the gear position, and the current speed direction of the drive motor; and determining whether the target vehicle is in a rolling slope state based on the current state of the target vehicle includes: determining whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction according to the vehicle driving state and gear position; If the desired rotational speed direction is inconsistent with the current rotational speed direction, determining that the target vehicle is in a rolling downhill state; 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 rolling downhill state.

3. The method according to claim 2, characterized in that The determining, based on the vehicle driving state and gear position, whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction includes: If the vehicle is in a forward state and the gear is in a forward gear, determining that the desired rotational speed direction of the drive motor is a positive rotational speed direction; Determining whether the current rotational speed direction is a positive rotational speed direction; If the current rotational speed direction is a 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 a negative rotational speed direction, it is determined 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, characterized in that The determining, based on the vehicle driving state and gear position, whether the desired rotational speed direction of the drive motor is consistent with the current rotational speed direction includes: If the vehicle is in a reverse state and the gear is in a reverse gear, determining that the desired rotational speed direction of the drive motor is a negative rotational speed direction; Determining whether the current rotational speed direction is a negative rotational speed direction; If the current rotational speed direction is a 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 a positive rotational speed direction, it is determined 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 The controlling the torque of the drive motor to change from the current command torque to the hill-holding assist output torque while maintaining zero speed includes: According to a preset torque step value, the torque of the drive motor is controlled to gradually transition from the current command torque to the hill-holding assist output torque while maintaining zero speed.

6. The method according to claim 1, characterized in that The controlling the torque of the drive motor to change from the hill-holding assist output torque to the current command torque includes: Calculating a torque difference according to the hill-holding assist output torque and the current command torque; querying a target torque step value according to the torque difference; According to the target torque step value, the torque of the drive motor is controlled to gradually change from the hill-holding assist output torque to the current command torque.

7. A control device, characterized in that: include: A processor and a storage medium, wherein the processor and the storage medium are communicatively connected via 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 hill-holding assist control method according to any one of claims 1 to 6.

Images