Method, device, medium, product for drag force control for electrically driven vehicles

Abstract

The application relates to the field of electrically driven vehicles, and particularly discloses a method for controlling the drag force of an electrically driven vehicle, which is used for vehicle electronic equipment and comprises the following steps: determining a vehicle speed control threshold according to vehicle information and road surface information; obtaining a driver desired torque from a vehicle management unit of the electrically driven vehicle; determining whether to perform drag force control based on a speed signal of a motor of the electrically driven vehicle and the vehicle speed control threshold; when it is determined that the drag force control is not performed, a motor controller of the electrically driven vehicle adjusts the torque of the motor in response to the driver desired torque; and when it is determined that the drag force control is performed, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver desired torque. The application has the advantage that the drag force can be controlled in time when the motor speed exceeds the allowable range of the current working condition (for example, a braking working condition), so that the negative influence caused by the drag force is reduced.

Description

Technical Field

[0001] This application relates to the field of electric vehicles, and in particular to a method, apparatus, medium, or product for controlling drag force in electric vehicles. Background Technology

[0002] In traditional electronic and electrical architectures, the Engine Torque Control (EDC) function integrated into the Electronic Stability Control (ESC) system typically calculates the actual tire slip ratio in real time based on wheel speed sensor signals, engine speed signals, and inertial measurement unit (IMU) signals. When the actual slip ratio exceeds the slip ratio threshold expected by the EDC, the EDC sends a torque increase request to the engine. This torque increase request needs to be transmitted to the gateway via the Chassis Controller Area Network (CAN). The gateway routes it to the Vehicle Control Unit (VCU) in the Body Control Domain for arbitration. The arbitration result is then routed via the gateway to the Engine Management System (EMS) or Motor Electronic Control Unit (Motor ECU) on the powertrain CAN, thereby achieving control of the engine or motor torque.

[0003] However, in the aforementioned existing technical solutions, the torque request signal from the EDC needs to be transmitted and processed through multiple nodes such as the ESC, gateway, VCU, and EMS / Motor ECU, resulting in a significant transmission delay from the EDC issuing the CAN command to the final execution by the engine or motor. This delay is typically above 70 milliseconds, and in cases of poor network architecture design, it can even reach over 150 milliseconds, severely impacting the real-time performance of control commands.

[0004] With the widespread adoption of electric vehicles, internal combustion engines are being replaced by electric motors, and traditional multi-speed transmission systems are being replaced by reducers. The power from the electric motor is directly transmitted to the wheel axles after passing through the reducer, resulting in a significant reduction in the rotational inertia of the entire drive system. Simultaneously, to improve driving range, automakers are continuously increasing the regenerative braking torque and coasting energy recovery torque. In this context, when the vehicle is on a low-traction surface, if the driver quickly releases the accelerator, the large coasting recovery torque will generate a strong drag effect on the wheels, causing the wheel speed to drop rapidly and quickly fall below the drag force control threshold of the electro-hydraulic automatic braking system. However, due to the aforementioned network latency, by the time the control command from the electro-hydraulic automatic braking system is transmitted to the motor and actually executed, the wheel speed has already dropped significantly, far exceeding the drag force control threshold, thus leading to decreased vehicle stability. Similarly, on low-traction surfaces, if the driver suddenly performs a forced braking maneuver, the slow response of the electric motor to the control command from the electro-hydraulic automatic braking system will further exacerbate the risk of decreased vehicle stability. Summary of the Invention

[0005] To achieve timely and accurate control of the drag force of an electric vehicle, this application proposes a drag force control method for electric vehicles, used in vehicle electronic equipment, comprising:

[0006] Based on vehicle information and road conditions, determine the vehicle speed control threshold;

[0007] The driver's desired torque is obtained from the vehicle management unit of the electric drive vehicle;

[0008] Based on the motor speed signal of the electric drive vehicle and the vehicle speed control threshold, it is determined whether to perform drag force control.

[0009] When it is determined that the drag force control is not performed, the motor controller of the electric drive vehicle adjusts the torque of the motor in response to the driver's desired torque.

[0010] When it is determined to perform the drag force control, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver's desired torque.

[0011] Optionally, the vehicle speed control threshold is a wheel speed threshold or a motor speed threshold; and when the vehicle speed threshold is the wheel speed threshold, the wheel speed threshold is converted to the motor speed threshold.

[0012] When the speed signal is less than the motor speed threshold, or rapidly approaches the motor speed threshold, it is determined to perform the drag force control.

[0013] When the speed signal is greater than the motor speed threshold, it is determined that the drag force control will not be performed.

[0014] Optionally, adjusting the motor torque based on the vehicle speed control threshold and the driver's desired torque includes:

[0015] The torque adjustment amount is calculated based on the speed deviation between the motor speed threshold and the motor speed signal;

[0016] The torque adjustment request signal is determined based on the torque adjustment amount;

[0017] The torque adjustment request signal is compared with the driver's desired torque to determine the torque adjustment signal;

[0018] The torque of the motor is adjusted based on the torque adjustment signal.

[0019] Optionally, calculating the torque adjustment based on the speed deviation between the motor speed threshold and the motor speed signal includes:

[0020] The acceleration signal can be obtained by differentiating the wheel speed threshold, or by directly acquiring the acceleration signal from the corresponding sensor.

[0021] The road surface adhesion coefficient is determined based on the acceleration signal and the first lookup table; wherein the first lookup table indicates the mapping relationship between the acceleration signal and the road surface adhesion coefficient.

[0022] Based on the speed deviation, the road surface adhesion coefficient, and the second lookup table, torque control parameters are determined; wherein, the second lookup table indicates the mapping relationship between the speed deviation, the road surface adhesion coefficient, and the torque control parameters;

[0023] The torque adjustment amount is calculated based on the torque control parameters and the speed deviation.

[0024] Optionally, the torque control parameters include proportional control parameters, integral control parameters, and derivative control parameters; and

[0025] The torque adjustment amount is calculated using the following formula:

[0026] PID_Tq=K1×(deviation)+K2×(∑deviation×dt)+K3×(d(deviation) / dt),

[0027] Wherein PID_Tq is the torque adjustment amount, K1 is the proportional control parameter, K2 is the integral control parameter, K3 is the derivative control parameter, and deviation is the speed deviation.

[0028] Optionally, the torque adjustment amount is added to the initial torque of the motor to obtain a torque adjustment request signal.

[0029] Optionally, the initial torque is determined based on the road surface adhesion coefficient and a third lookup table; wherein the third lookup table indicates the mapping relationship between the road surface adhesion coefficient and the initial torque.

[0030] Optionally, when the torque adjustment request signal is less than the driver's desired torque, the torque adjustment signal is the driver's desired torque;

[0031] When the torque adjustment request signal is greater than the driver's desired torque, the torque adjustment signal is the torque adjustment request signal.

[0032] Optionally, after performing the drag force control, the drag force control shall be stopped when the following conditions are met simultaneously:

[0033] The motor speed signal is greater than the motor speed threshold;

[0034] The activation time of the torque adjustment request signal reaches a time threshold; and

[0035] The torque adjustment request signal is less than the torque desired by the driver.

[0036] Another aspect of this application provides a drag force control system for an electric vehicle, characterized in that it includes:

[0037] The threshold acquisition unit is used to determine the vehicle speed control threshold based on vehicle information and road surface information;

[0038] A desired torque unit is used to obtain the driver's desired torque from the vehicle management unit of the electric drive vehicle;

[0039] A speed control unit is configured to determine whether to perform drag force control based on the speed signal of the motor of the electric drive vehicle and the vehicle speed control threshold; when it is determined that drag force control should not be performed, the motor controller of the electric drive vehicle adjusts the torque of the motor in response to the driver's desired torque; when it is determined that drag force control should be performed, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver's desired torque.

[0040] Another aspect of this application provides an electronic device, the device including a memory storing computer-executable instructions and a processor; when the instructions are executed by the processor, the device causes the device to perform the method according to any of the foregoing.

[0041] Another aspect of this application provides a computer-readable storage medium storing one or more programs that can be executed by one or more processors to implement the method described in any of the preceding claims.

[0042] Another aspect of this application provides a computer program product including a computer program that, when executed by a processor, implements the method as described in any of the preceding claims.

[0043] The technical solution provided by the embodiments of this application has at least the following technical effects: by determining the optimal vehicle speed control threshold based on vehicle information and road information, and by comprehensively judging whether drag force control is required based on the current motor speed signal and the vehicle speed control threshold, drag force can be controlled in a timely manner when the motor speed exceeds the allowable range of the current working condition (e.g., braking condition), thereby reducing the negative impact of drag force.

[0044] When drag force control is determined, the motor torque is adjusted based on the vehicle speed control threshold and the driver's desired torque. This allows for direct limitation of the driving force from the motor torque side. When the motor speed approaches or exceeds the drag force control threshold signal issued by the electro-hydraulic automatic braking device, the motor torque is immediately adjusted. This allows for faster control of the motor speed, reduces overshoot, and thus improves vehicle stability.

[0045] Furthermore, by determining torque control parameters based on speed deviation, road surface adhesion coefficient, and lookup tables, and calculating torque adjustment based on these parameters, the torque adjustment process can dynamically change with road surface adhesion and motor speed deviation, thereby improving the adaptability and robustness of the drag force control method to different road conditions. By comparing the torque adjustment request signal with the driver's desired torque to determine the torque adjustment signal, it is also possible to avoid the torque determined by drag force control not matching the driver's actual needs while adjusting the motor output torque, thus balancing vehicle stability and driver power requirements.

[0046] In summary, the drag force control system proposed in this application allows the electro-hydraulic automatic braking device to leverage its rich experience in vehicle dynamics and fully utilizes the low-latency motor speed to calculate the drag force, thus significantly improving the performance of the drag force control system. Attached Figure Description

[0047] Figure 1 This is a flowchart of a drag force control method for an electrically driven vehicle according to an embodiment of this application.

[0048] Figure 2 This is a flowchart of a method for adjusting motor torque based on a vehicle speed control threshold and the driver's desired torque, according to an embodiment of this application.

[0049] Figure 3 This is a flowchart illustrating an embodiment of calculating torque adjustment using PID control according to the present application.

[0050] Figure 4 This is a schematic diagram of a drag force control system for an electrically driven vehicle according to an embodiment of this application.

[0051] Figure 5 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0053] Figure 1 This is a flowchart of a drag force control method for an electrically driven vehicle according to an embodiment of this application.

[0054] In step 101, the vehicle speed control threshold is determined based on the vehicle information and road information, and the driver's desired torque is obtained from the vehicle management unit of the electric drive vehicle.

[0055] Vehicle information can include information related to the vehicle's own parameters, such as vehicle speed, gear position, and operating mode. Road information can include information related to the road surface, such as road type or condition. Both vehicle and road information can be provided by corresponding sensors, controllers, or pre-set calibration data within the vehicle. The vehicle speed control threshold characterizes the lower limit of the permissible speed under the current vehicle operating condition (braking condition). The vehicle speed control threshold can be either a wheel speed threshold or a motor speed threshold. The wheel speed threshold and motor speed threshold can be converted between each other based on the transmission ratio of the electric drive vehicle.

[0056] The driver's desired torque represents the driver's demand for vehicle driving force and can be reflected through the driver's actions. For example, it can be calculated by the vehicle management unit based on information such as accelerator pedal opening, accelerator pedal change rate, and gear position. This application does not limit the specific algorithms for determining the vehicle speed control threshold and the driver's desired torque. Those skilled in the art can determine them using appropriate calibration, calculation, or lookup table methods according to the vehicle type and control requirements.

[0057] In step 102, when the speed signal of the electric motor of the electric drive vehicle is less than the vehicle speed control threshold, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver's desired torque to perform drag force control.

[0058] When the vehicle speed control threshold is the wheel speed threshold, it can first be converted into a motor speed threshold based on the transmission ratio of the vehicle's transmission system. Then, the motor speed signal is compared with the motor speed threshold. The motor speed signal can be acquired by a rotary transformer, encoder, or other speed detection device installed on the motor.

[0059] When the motor speed signal is lower than the motor speed threshold, or rapidly approaches the motor speed threshold, it indicates that the motor speed poses a risk to vehicle stability, requiring drag control. In this case, the motor torque is adjusted based on the vehicle speed control threshold and the driver's desired torque to perform drag control. During drag control, the motor torque needs to be adjusted according to the vehicle speed control threshold, while simultaneously considering the driver's desired torque.

[0060] When the motor speed signal is greater than or equal to the motor speed threshold, it indicates that the current motor speed has not exceeded the speed range allowed by the current vehicle operating conditions, and drag control is not required. At this time, the electric drive vehicle's motor controller adjusts the motor torque in response to the driver's desired torque. For example, the motor controller can use the driver's desired torque as the target torque for the motor.

[0061] Figure 2 This is a flowchart of a method for adjusting motor torque based on a vehicle speed control threshold and the driver's desired torque, according to an embodiment of this application.

[0062] In step 201, the torque adjustment is calculated based on the speed deviation between the motor speed threshold and the motor speed signal. The speed deviation characterizes the degree of deviation of the current motor speed from the motor speed threshold. In one example, the speed deviation can be defined as the difference between the motor speed threshold and the motor speed signal. The torque adjustment can be calculated using proportional-integral-derivative (PID) control, AI control, fuzzy control, or other closed-loop control methods.

[0063] Figure 3 This is a flowchart illustrating an implementation method for calculating torque adjustment using PID control.

[0064] In step 301, the acceleration signal is obtained by differentiating the wheel speed threshold, or it can be directly acquired from the corresponding sensor. When the vehicle speed control threshold is the motor speed threshold, the motor speed threshold can also be converted to a wheel speed threshold based on the transmission ratio of the vehicle's transmission system, and then the wheel speed threshold can be differentiated. In some embodiments, the acceleration signal can be directly acquired from a longitudinal acceleration sensor, inertial measurement unit, or other sensors capable of detecting vehicle acceleration.

[0065] In step 302, the road surface adhesion coefficient is determined based on the acceleration signal and a first lookup table. The road surface adhesion coefficient characterizes the adhesion capability that the tire can provide between the tire and the current road surface. The first lookup table indicates the mapping relationship between the acceleration signal and the road surface adhesion coefficient under braking conditions. The first lookup table can be pre-established through vehicle testing, simulation, or calibration and stored in the electronic device executing the method of this application. For example, vehicle acceleration and the corresponding road surface adhesion coefficient can be collected on different types of road surfaces to establish the correspondence between the acceleration signal and the road surface adhesion coefficient. The electronic device can look up the corresponding road surface adhesion coefficient in the first lookup table based on the current acceleration signal. An example of the first lookup table is shown in the table below:

[0066] First lookup table

[0067]

[0068] In addition, when the current acceleration signal is located between two calibration points in the first lookup table, the road surface adhesion coefficient can also be determined by linear interpolation or other interpolation methods.

[0069] In step 303, torque control parameters are determined based on the speed deviation, road surface adhesion coefficient, and a second lookup table. The second lookup table is a two-dimensional lookup table used to indicate the mapping relationship between speed deviation, road surface adhesion coefficient, and torque control parameters. The second lookup table can be pre-obtained through vehicle testing or control parameter calibration and stored in an electronic device. For different combinations of speed deviation and road surface adhesion coefficient, the second lookup table can be set with corresponding torque control parameters to adapt the drag force control process to different road surface adhesion conditions and wheel slippage. The specific values ​​and variation patterns of the torque control parameters can be calibrated according to the vehicle's power performance, comfort, and stability requirements. In this PID control method, the second lookup table can be three separate lookup tables for proportional control parameters, integral control parameters, and derivative control parameters, or they can be integrated into one table. An example of the second lookup table is shown in the table below, where second lookup table-1 is used to look up proportional control parameters, second lookup table-2 is used to look up integral control parameters, and second lookup table-3 is used to look up derivative control parameters.

[0070] Second lookup table - 1

[0071]

[0072] Second lookup table - 2

[0073]

[0074] Second lookup table - 3

[0075]

[0076] In step 304, the torque adjustment is calculated based on the torque control parameters and speed deviation. Taking a discrete control process as an example, the torque adjustment can be calculated using the following formula:

[0077] PID_Tq=K1×(deviation)+K2×(∑deviation×dt)+K3×(d(deviation) / dt).

[0078] Where PID_Tq is the torque adjustment amount, K1, K2, and K3 are the proportional control parameter, integral control parameter, and derivative control parameter, respectively, deviation is the speed deviation, ∑deviation×dt is the integral form of the speed deviation, and d(deviation) / dt is the derivative form of the speed deviation.

[0079] The proportional term adjusts the motor torque based on the current speed deviation, the integral term reduces steady-state error based on the accumulated speed deviation over a period of time, and the derivative term suppresses rapid changes in motor speed based on the trend of speed deviation. By dynamically selecting proportional, integral, and derivative control parameters based on the road adhesion coefficient and speed deviation, the PID controller can adapt to different road conditions and improve the robustness of drag force control.

[0080] In step 202, a torque adjustment request signal is determined based on the torque adjustment amount.

[0081] In some implementations, the torque adjustment amount can be added to the initial torque of the motor to obtain the torque adjustment request signal, i.e.: Tq_req = Tq_Ini + PID_Tq. Here, Tq_req is the torque adjustment request signal, and Tq_Ini is the initial torque of the motor. The initial torque of the motor can be a reference torque determined when entering the current drag force control process.

[0082] In some implementations, the initial torque of the motor can be determined based on the road surface adhesion coefficient and a third lookup table. The third lookup table indicates the mapping relationship between the road surface adhesion coefficient and the initial torque and can be pre-established through vehicle testing or calibration. An example of a third lookup table is shown in the table below:

[0083] Third lookup table

[0084]

[0085] The first lookup table, the second lookup table, and the third lookup table mentioned above can be set up separately, or they can be stored as different data tables in the same set of calibration data.

[0086] In step 203, the torque adjustment request signal is compared with the driver's desired torque to determine the torque adjustment signal.

[0087] When the torque adjustment request signal is greater than the driver's desired torque, the torque adjustment request signal is determined as the torque adjustment signal; when the torque adjustment request signal is less than the driver's desired torque, the driver's desired torque is determined as the torque adjustment signal. In other words, the larger of the torque adjustment request signal and the driver's desired torque can be determined as the torque adjustment signal.

[0088] During braking, the ABS function may adjust wheel cylinder pressure to control tire slippage. The electro-hydraulic automatic braking system then requests the open-loop torque request from the drag force control mechanism to coordinate the drag force control program in the motor controller with the ABS function's slippage control. At this point, the open-loop requested torque and the torque adjustment request signal can be compared, and the larger one is taken as the torque adjustment signal. This signal is then compared with the driver's desired torque.

[0089] Through the above comparison, drag force control can be mainly used to limit the output torque of the motor, so as to avoid the torque determined by drag force control being lower than the torque determined by the vehicle speed control threshold.

[0090] In step 204, the torque of the motor is adjusted based on the torque adjustment signal.

[0091] The motor controller can use the torque adjustment signal as the target torque and adjust the actual output torque of the motor according to the target torque. In some implementations, the torque adjustment signal can be further adjusted based on the motor's permissible output torque, the battery's permissible discharge power, and other vehicle safety limitations.

[0092] By directly adjusting the motor torque using the motor speed signal in a closed loop, the motor torque can be reduced promptly when the motor speed exceeds or approaches a threshold. This reduces the impact of network transmission and execution delays between the electro-hydraulic automatic braking device and the motor controller on the timeliness of drag force control. Furthermore, by adjusting the torque control parameters and initial torque according to the road surface adhesion coefficient, the adaptability of the drag force control method under different road surface conditions can be improved.

[0093] In some implementations, after drag force control is performed, it can be continuously determined whether the conditions for stopping drag force control are met. Dragging force control is stopped when the motor speed signal is greater than the motor speed threshold, the activation time of the torque adjustment request signal reaches a preset time threshold, and the torque adjustment request signal is less than the torque desired by the driver.

[0094] The activation time of the torque adjustment request signal can be timed from the moment the current drag control state is entered or the torque adjustment request signal is first output. Setting a time threshold can prevent frequent entry and exit from drag control due to a brief drop in motor speed. When the motor speed signal is greater than the motor speed threshold, it indicates that the motor speed has returned to the allowable range; when the torque adjustment request signal is less than the torque expected by the driver, it indicates that the torque actually requested by the driver will not cause the vehicle to slip. When both of the above conditions are met, the vehicle can be considered to have returned to a stable operating state, and therefore drag control can be exited.

[0095] In another embodiment, this application also provides a drag force control system for an electrically driven vehicle. For example... Figure 4 As shown, the drag force control system 400 includes a threshold acquisition unit 401 and a torque adjustment unit 402.

[0096] Threshold acquisition unit 401 is used to determine the vehicle speed control threshold based on vehicle information and road information, and to obtain the driver's desired torque from the vehicle management unit of the electric drive vehicle. Torque adjustment unit 402 is used to adjust the motor torque based on the vehicle speed control threshold and the driver's desired torque when the motor speed signal of the electric drive vehicle is less than the vehicle speed control threshold, thereby performing drag force control.

[0097] In some embodiments, the torque adjustment unit 402 can also be used to calculate the speed deviation between the motor speed threshold and the motor speed signal, calculate the torque adjustment amount based on the speed deviation, determine the torque adjustment request signal based on the torque adjustment amount, compare the torque adjustment request signal with the driver's desired torque to determine the torque adjustment signal, and control the motor torque based on the torque adjustment signal. Detailed explanations can be found in the embodiments described above for the drag force control method, and will not be repeated here.

[0098] Now for reference Figure 5 The diagram shown is a block diagram of an electronic device 500 according to an embodiment of the present application. The electronic device 500 may include one or more processors 502, system control logic 508 connected to at least one of the processors 502, system memory 504 connected to the system control logic 508, non-volatile memory (NVM) 506 connected to the system control logic 508, and network interface 510 connected to the system control logic 508.

[0099] Processor 502 may include one or more single-core or multi-core processors. Processor 502 may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, baseband processors, etc.). In embodiments herein, processor 502 may be configured to perform one or more embodiments of the drag force control method for an electrically driven vehicle according to this application.

[0100] In some embodiments, system control logic 508 may include any suitable interface controller to provide any suitable interface to at least one of the processors 502 and / or any suitable device or component communicating with system control logic 508.

[0101] In some embodiments, system control logic 508 may include one or more memory controllers to provide an interface to system memory 504. System memory 504 may be used to load and store data and / or instructions. In some embodiments, system memory 504 of electronic device 500 may include any suitable volatile memory, such as suitable dynamic random access memory (DRAM).

[0102] The nonvolatile memory 506 may include one or more tangible, non-transitory computer-readable storage media for storing data and / or instructions. In some embodiments, the nonvolatile memory 506 may include any suitable nonvolatile memory such as flash memory and / or any suitable nonvolatile storage device, such as at least one of HDD (Hard Disk Drive), CD (Compact Disc) drive, and DVD (Digital Versatile Disc) drive.

[0103] The non-volatile memory 506 may include a portion of the storage resources installed on the device of the electronic device 500, or it may be accessible by the device, but is not necessarily part of the device. For example, the non-volatile memory 506 may be accessed over a network via the network interface 510.

[0104] Specifically, system memory 504 and non-volatile memory 506 may each include a temporary copy and a permanent copy of instructions 520. Instructions 520 may include instructions that, when executed by at least one of processors 502, cause electronic device 500 to implement the methods provided in this application. In some embodiments, instructions 520, hardware, firmware, and / or their software components may additionally / alternatively reside in system control logic 508, network interface 510, and / or processor 502.

[0105] In some embodiments, network interface 510 may be integrated into other components of electronic device 500. For example, network interface 510 may be integrated into at least one of processor 502, system memory 504, non-volatile memory 506, and firmware device (not shown) having instructions that, when at least one of processor 502 executes the instructions, electronic device 500 implements one or more embodiments of the various embodiments described herein. Network interface 510 may further include any suitable hardware and / or firmware to provide a multiple-input multiple-output radio interface.

[0106] In one embodiment, at least one of the processors 502 may be packaged together with the logic of one or more controllers for system control logic 508 to form a system package (SiP). In another embodiment, at least one of the processors 502 may be integrated on the same die with the logic of one or more controllers for system control logic 508 to form a system on chip (SoC).

[0107] Electronic device 500 may further include: input / output (I / O) device 512. Input / output (I / O) device 512 may include a user interface that enables a user to interact with electronic device 500; the design of peripheral component interfaces enables peripheral components to also interact with electronic device 500.

[0108] In some embodiments, the user interface may include, but is not limited to, a display (e.g., a liquid crystal display, a touch screen display, etc.), a speaker, a microphone, one or more cameras (e.g., a still image camera and / or a video camera), a flashlight (e.g., a light-emitting diode flash), and a keyboard.

[0109] In some embodiments, the peripheral component interface may include, but is not limited to, a non-volatile memory port, an audio jack, and a power interface.

[0110] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on the electronic device 500. In other embodiments of this application, the electronic device 500 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0111] Program code can be applied to input instructions to perform the functions described herein and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), or a microprocessor.

[0112] The program code can be implemented using a high-level procedural language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used when needed. In fact, the mechanisms described in this paper are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0113] One or more aspects of at least one embodiment can be implemented by representational instructions stored on a computer-readable storage medium, the instructions representing various logics in a processor, which, when read by a machine, cause the machine to create logic for performing the techniques described herein. These representations, referred to as “IP cores,” can be stored on a tangible computer-readable storage medium and provided to multiple customers or production facilities for loading into manufacturing machines that actually manufacture the logic or processor.

[0114] One embodiment of this application discloses a computer-readable storage medium storing one or more programs executable by one or more processors to implement the drag force control method for an electrically driven vehicle of this application.

[0115] One embodiment of this application discloses a computer program product, including a computer program that, when executed by a processor, implements the drag force control method for an electrically driven vehicle of this application.

[0116] The specific embodiments described above illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application is presented in conjunction with preferred embodiments, this does not mean that the features of this invention are limited to these embodiments. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0117] Furthermore, the various operations will be described as multiple discrete operations in a manner most conducive to understanding the illustrative embodiments; however, the order of description should not be construed as implying that these operations must depend on the order. In particular, these operations do not need to be performed in the order presented.

[0118] Unless the context otherwise specifies, the terms “contains,” “has,” and “includes” are synonyms. The phrase “A / B” means “A or B.” The phrase “A and / or B” means “(A and B) or (A or B).”

[0119] As used herein, the terms “module” or “unit” may refer to, be, or include: application-specific integrated circuits (ASICs), electronic circuits, (shared, dedicated, or group) processors and / or memories that execute one or more software or firmware programs, combinational logic circuits, and / or other suitable components that provide the described functionality.

[0120] In the accompanying drawings, certain structural or methodological features are shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be necessary. In some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. Furthermore, the inclusion of structural or methodological features in a particular figure does not imply that such features are required in all embodiments, and in some embodiments, these features may be omitted or may be combined with other features.

[0121] It should be understood that although terms such as "first," "second," etc., may be used herein to describe various units or data, these units or data should not be limited by these terms. These terms are used merely to distinguish one feature from another. For example, without departing from the scope of the exemplary embodiments, a first feature may be referred to as a second feature, and similarly, a second feature may be referred to as a first feature.

[0122] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0123] Although the invention has been illustrated and described with reference to certain preferred embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims

1. A drag force control method for an electric vehicle, used in vehicle electronic equipment, characterized in that, include: Based on vehicle information and road conditions, determine the vehicle speed control threshold; The driver's desired torque is obtained from the vehicle management unit of the electric drive vehicle; Based on the motor speed signal of the electric drive vehicle and the vehicle speed control threshold, it is determined whether to perform drag force control. When it is determined that the drag force control is not performed, the motor controller of the electric drive vehicle adjusts the torque of the motor in response to the driver's desired torque. When it is determined to perform the drag force control, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver's desired torque.

2. The method according to claim 1, characterized in that, The vehicle speed control threshold is either a wheel speed threshold or a motor speed threshold; and when the vehicle speed threshold is the wheel speed threshold, the wheel speed threshold is converted to the motor speed threshold. When the speed signal is less than the motor speed threshold, or rapidly approaches the motor speed threshold, it is determined to perform the drag force control. When the speed signal is greater than the motor speed threshold, it is determined that the drag force control will not be performed.

3. The method according to claim 1, characterized in that, The method of adjusting the motor torque based on the vehicle speed control threshold and the driver's desired torque includes: The torque adjustment amount is calculated based on the speed deviation between the motor speed threshold and the motor speed signal; The torque adjustment request signal is determined based on the torque adjustment amount; The torque adjustment request signal is compared with the driver's desired torque to determine the torque adjustment signal; The torque of the motor is adjusted based on the torque adjustment signal.

4. The method according to claim 3, characterized in that, The calculation of torque adjustment based on the speed deviation between the motor speed threshold and the motor speed signal includes: The acceleration signal can be obtained by differentiating the wheel speed threshold, or by directly acquiring the acceleration signal from the corresponding sensor. The road surface adhesion coefficient is determined based on the acceleration signal and the first lookup table; wherein the first lookup table indicates the mapping relationship between the acceleration signal and the road surface adhesion coefficient. Based on the speed deviation, the road surface adhesion coefficient, and the second lookup table, torque control parameters are determined; wherein, the second lookup table indicates the mapping relationship between the speed deviation, the road surface adhesion coefficient, and the torque control parameters; The torque adjustment amount is calculated based on the torque control parameters and the speed deviation.

5. The method according to claim 4, characterized in that, The torque control parameters include proportional control parameters, integral control parameters, and derivative control parameters; and The torque adjustment amount is calculated using the following formula: PID_Tq=K1×(deviation)+K2×(∑deviation×dt)+K3×(d(deviation) / dt), Wherein PID_Tq is the torque adjustment amount, K1 is the proportional control parameter, K2 is the integral control parameter, K3 is the derivative control parameter, and deviation is the speed deviation.

6. The method according to claim 3, characterized in that, The torque adjustment amount is added to the initial torque of the motor to obtain the torque adjustment request signal.

7. The method according to claim 6, characterized in that, The initial torque is determined based on the road surface adhesion coefficient and a third lookup table; wherein the third lookup table indicates the mapping relationship between the road surface adhesion coefficient and the initial torque.

8. The method according to claim 3, characterized in that, When the torque adjustment request signal is less than the driver's desired torque, the torque adjustment signal is the driver's desired torque; When the torque adjustment request signal is greater than the driver's desired torque, the torque adjustment signal is the torque adjustment request signal.

9. The method according to claim 1, characterized in that, After the aforementioned drag force control is performed, the drag force control shall be stopped when the following conditions are met simultaneously: The motor speed signal is greater than the motor speed threshold; The activation time of the torque adjustment request signal reaches a time threshold; and The torque adjustment request signal is less than the torque desired by the driver.

10. A drag force control system for an electric vehicle, characterized in that, include: The threshold acquisition unit is used to determine the vehicle speed control threshold based on vehicle information and road surface information; A desired torque unit is used to obtain the driver's desired torque from the vehicle management unit of the electric drive vehicle; A speed control unit is used to determine whether to perform drag force control based on the speed signal of the motor of the electric drive vehicle and the vehicle speed control threshold. When it is determined that the drag force control is not performed, the motor controller of the electric drive vehicle adjusts the torque of the motor in response to the driver's desired torque. When it is determined to perform the drag force control, the torque of the motor is adjusted based on the vehicle speed control threshold and the driver's desired torque.

11. An electronic device, characterized in that, The device includes a memory storing computer-executable instructions and a processor; when the instructions are executed by the processor, the device performs the method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more programs, which can be executed by one or more processors to implement the method of any one of claims 1 to 9.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 9.

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