A vehicle creeping control method and related device

Abstract

The application discloses a kind of automobile crawl control method and related device.The method provided in the application obtains vehicle operation data and when satisfying the crawl condition, the crawl torque is dynamically determined based on actual driving speed and target crawl speed, and the crawl torque is superimposed and output with drive pedal torque.By the way of superimposing crawl torque and drive pedal torque to control vehicle, smooth transition from normal driving to crawl mode is realized.The method constructs closed-loop control through dynamic torque adjustment, improves the control accuracy of crawl speed, and effectively optimizes the smoothness, accuracy and scene adaptation capability of electric vehicle crawl process.

Description

Technical Field

[0001] This application relates to the field of automotive control technology, and in particular to a method and related apparatus for controlling vehicle crawling. Background Technology

[0002] Crawl refers to the slow movement of a vehicle without pressing the drive pedal. Crawl is commonly used in low-speed scenarios such as following other vehicles in traffic jams, preventing vehicles from rolling back on slopes, and maneuvering at low speeds.

[0003] Traditional gasoline-powered cars rely on engine idling speed for creeping, which may be accompanied by slight vibrations or jerks. In contrast, electric vehicles are mostly driven directly by the electric motor, resulting in a smoother and more adjustable creeping motion.

[0004] However, electric vehicles still experience some vibration when entering and exiting crawl mode, resulting in a poor user experience. Summary of the Invention

[0005] In view of the above problems, this application provides a method.

[0006] The embodiments of this application disclose the following technical solutions:

[0007] In a first aspect, embodiments of this application disclose a method for controlling vehicle crawling, characterized in that the method includes:

[0008] Obtain vehicle operating data;

[0009] When the operating data meets the preset conditions for entering the crawl mode, the crawl torque is determined based on the actual driving speed of the vehicle and the target crawl speed of the vehicle;

[0010] The creep torque and the vehicle's drive pedal torque are superimposed to control the vehicle's actual driving speed to approach the target creep speed.

[0011] In one possible implementation, determining the creep torque based on the vehicle's actual driving speed and the vehicle's target creep speed includes:

[0012] The creep torque is obtained by proportional and integral calculations of the target creep speed and the actual driving speed using a speed loop PI controller.

[0013] In one possible implementation, the creep torque is obtained by performing proportional and integral calculations on the target creep speed and the actual driving speed using a speed loop PI controller, including:

[0014] Determine the speed difference obtained by subtracting the actual travel speed from the target creep speed;

[0015] When the vehicle's brake pedal is depressed, the first torque is calculated by integrating the speed difference and the first integral coefficient; when the vehicle's brake pedal is not depressed, the first torque is calculated by integrating the speed difference and the second integral coefficient.

[0016] The second torque is obtained based on the speed difference and the proportional coefficient;

[0017] The creeping torque is obtained by adding the first torque and the second torque.

[0018] In one possible implementation, the method further includes stopping the integral accumulation when the cumulative integral value is greater than or equal to the maximum creep torque value during the integral calculation based on the speed difference.

[0019] In one possible implementation, the method further includes:

[0020] If the running data meets the preset conditions for exiting the crawl mode, the crawl mode is exited using a first method, a second method, or a third method based on the running data; wherein, the speed of exiting the crawl mode using the first method is greater than the speed of exiting the crawl mode using the second method, and the speed of exiting the crawl mode using the second method is greater than the speed of exiting the crawl mode using the third method.

[0021] In one possible implementation, the preset conditions for exiting the crawl mode include:

[0022] The vehicle exits the preparation mode; the vehicle is in parking or neutral; the vehicle's automatic parking function is activated; the vehicle's speed exceeds the creep speed threshold; the vehicle's brake pedal is depressed; the vehicle has a malfunction that affects its normal operation.

[0023] In one possible implementation, the step of exiting the crawl mode by adopting a first, second, or third method based on the running data when the running data meets the preset conditions for exiting the crawl mode includes:

[0024] If the vehicle exits the preparation mode, the vehicle is in parking or neutral, the vehicle's automatic parking function is activated, or the vehicle has a malfunction that affects normal driving, the first method shall be used to exit the crawl mode.

[0025] When the vehicle's brake pedal is depressed, exit the crawl mode using the second method;

[0026] If the vehicle speed exceeds the creep speed threshold, the third method is used to exit the creep mode.

[0027] In one possible implementation, exiting the creep mode using the first method includes:

[0028] Set the creep torque output by the speed loop PI controller to 0, and set the first torque obtained by accumulating the integral term in the speed loop PI controller to 0;

[0029] Exiting the crawl mode using the second method includes:

[0030] Set the target creep speed input to the speed loop PI controller to 0;

[0031] Exiting the crawl mode using the third method includes:

[0032] The target creeping speed input to the speed loop PI controller remains constant.

[0033] Secondly, embodiments of this application disclose a vehicle crawl control device, which includes:

[0034] The acquisition module is used to acquire vehicle operating data;

[0035] The determination module is used to determine the creep torque based on the actual driving speed of the vehicle and the target creep speed of the vehicle when the operating data meets the preset conditions for entering the creep mode;

[0036] The control module is used to superimpose the creep torque and the drive pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target creep speed.

[0037] In one possible implementation, a determining module is specifically used to perform proportional and integral calculations on the target creep speed and the actual driving speed using a speed loop PI controller to obtain the creep torque.

[0038] In one possible implementation, the determining module is specifically configured to determine the speed difference obtained by subtracting the actual driving speed from the target creep speed; when the vehicle's brake pedal is depressed, to calculate a first torque by integrating the speed difference and a first integral coefficient; when the vehicle's brake pedal is not depressed, to calculate the first torque by integrating the speed difference and a second integral coefficient; to obtain a second torque by integrating the speed difference and a proportional coefficient; and to sum the first torque and the second torque to obtain the creep torque.

[0039] In one possible implementation, the determining module is further configured to stop the integral accumulation when the cumulative integral value is greater than or equal to the maximum creep torque during the integral calculation based on the speed difference.

[0040] In one possible implementation, the control module is further configured to exit the crawling mode by adopting a first method, a second method, or a third method based on the running data when the running data meets the preset conditions for exiting the crawling mode; wherein, the speed of exiting the crawling mode by adopting the first method is greater than the speed of exiting the crawling mode by adopting the second method, and the speed of exiting the crawling mode by adopting the second method is greater than the speed of exiting the crawling mode by adopting the third method.

[0041] In one possible implementation, the preset conditions for exiting the crawl mode include: the vehicle exiting the preparation mode; the vehicle being in parking or neutral; the vehicle's automatic parking function being activated; the vehicle's speed exceeding the crawl speed threshold; the vehicle's brake pedal being depressed; and the vehicle having a malfunction that affects its normal operation.

[0042] In one possible implementation, the control module is specifically configured to exit the creep mode in the following situations: when the vehicle exits the preparation mode, the vehicle is in parking or neutral, the vehicle's automatic parking function is activated, or the vehicle has a malfunction that affects normal driving; exit the creep mode in the following situation: when the vehicle's brake pedal is depressed; and exit the creep mode in the following situation: when the vehicle's speed exceeds the creep speed threshold.

[0043] In one possible implementation, the control module exits the creep mode using the first method, specifically including:

[0044] Set the creep torque output by the speed loop PI controller to 0, and set the first torque obtained by accumulating the integral term in the speed loop PI controller to 0;

[0045] The control module exits the creep mode using the second method, specifically including:

[0046] Set the target creep speed input to the speed loop PI controller to 0;

[0047] The control module exits the creep mode using the third method, specifically including:

[0048] The target creeping speed input to the speed loop PI controller remains constant.

[0049] Thirdly, embodiments of this application disclose a control device, including a processor and a memory, wherein the memory is used to store programs, instructions or code, and the processor is used to execute the programs, instructions or code in the memory to perform the vehicle crawl control method as described in any of the first aspects.

[0050] Fourthly, embodiments of this application disclose a computer-readable storage medium storing a computer program, which is loaded by a processor to execute the vehicle crawl control method as described in any of the first aspects.

[0051] This application discloses a vehicle creep control method and related apparatus. The method acquires vehicle operating data and, when creep conditions are met, dynamically determines the creep torque based on the actual driving speed and the target creep speed. This creep torque is then superimposed on the drive pedal torque for output. By controlling the vehicle through the superposition of the creep torque and the drive pedal torque, a smooth transition from normal driving to creep mode is achieved. This method constructs a closed-loop control through dynamic torque adjustment, improving the control accuracy of the creep speed and effectively optimizing the smoothness, accuracy, and scenario adaptability of the electric vehicle's creep process. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 A flowchart illustrating a vehicle creep control method provided in an embodiment of this application;

[0054] Figure 2 A schematic diagram of a speed loop PI controller provided in an embodiment of this application;

[0055] Figure 3 This is a flowchart illustrating another vehicle creep control method provided in an embodiment of this application. Detailed Implementation

[0056] Currently, electric vehicles use a switch to control entry and exit from crawl mode. When the vehicle needs to enter crawl mode, torque control is applied based on the torque meter corresponding to crawl mode; when the vehicle needs to exit crawl mode, torque control is applied based on the torque meter corresponding to normal driving mode. However, the switching of the torque meter when entering or exiting crawl mode causes the vehicle to vibrate.

[0057] To address this issue, this application provides a vehicle creep control method. By acquiring vehicle operating data and dynamically determining the creep torque based on the actual driving speed and target creep speed when creep conditions are met, this creep torque is then superimposed on the drive pedal torque for output. This fundamentally changes the open-loop control logic in existing technologies that relies on torque meter switching between normal driving and creep modes. This design not only avoids the jitter problem caused by torque meter switching and achieves a smooth transition from normal driving to creep mode, but also constructs a closed-loop control through dynamic torque adjustment, improving the control accuracy of creep speed and effectively optimizing the smoothness, accuracy, and scenario adaptability of the electric vehicle's creep process.

[0058] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0059] like Figure 1 As shown, Figure 1 This is a flowchart illustrating a vehicle creep control method provided in an embodiment of this application. The control method provided in this application can be implemented by a vehicle control unit (VCU) in the vehicle. The following description uses the VCU as the executing entity to illustrate this control method. The method includes:

[0060] S101: VCU acquires vehicle operating data.

[0061] Operational data describes the vehicle's operating status. The Vehicle Control Unit (VCU) can collect and aggregate various parameters reflecting the vehicle's operating status in real time through data transmission channels such as onboard sensors and the CAN bus, forming a complete set of operational data. The VCU completes this process synchronously through hardware-level signal acquisition and software-level data integration, ensuring that the acquired operational data reflects the vehicle's current dynamic state in real time, providing a basis for subsequent judgments on whether to enter crawl mode and for calculating crawl torque.

[0062] As an example, operational data may include actual driving speed, gear position signal, vehicle readiness signal, drive pedal signal, brake pedal signal, handbrake signal, vehicle fault level, and automatic parking activation status.

[0063] Actual driving speed refers to the vehicle's current driving speed monitored in real time by a vehicle speed sensor. This speed is used to determine if the vehicle is in a low-speed state and to adjust creep torque. The gear position signal reflects the vehicle's current gear, which includes Drive (D), Reverse (R), Neutral (N), and Parking (P). The vehicle readiness signal indicates whether the vehicle's powertrain is ready. The drive pedal signal indicates the depth of the drive pedal, specifically obtained from the pedal position sensor. This signal is used to determine if the driver intends to accelerate. The brake pedal signal reflects the depth of the brake pedal; if the brake is engaged, the conditions for entering creep mode are usually not met. The handbrake signal indicates the parking brake status; the vehicle cannot enter creep mode when the handbrake is activated. The vehicle fault level characterizes the fault status of various vehicle systems (such as the powertrain and braking systems). If the fault level reaches a threshold affecting driving safety, creep mode activation will be restricted. The AutoHold activation status indicates whether the AutoHold function is enabled. When AutoHold is activated, the vehicle is in a stationary and locked state and must be released before entering crawl mode.

[0064] The operational data constructs a complete picture of vehicle operation from multiple dimensions such as vehicle power status, driver's operating intention, and safety status, providing comprehensive and real-time input basis for subsequent judgment and control of crawl mode.

[0065] S102: When the operating data meets the preset conditions for entering the crawl mode, the VCU determines the crawl torque based on the vehicle's actual driving speed and the vehicle's target crawl speed.

[0066] The preset conditions for entering crawl mode are used to determine whether the vehicle needs to or can enter crawl mode. As an example, preset conditions for entering crawl mode may include a vehicle readiness signal indicating the vehicle is in readiness mode, the vehicle being in drive or reverse, the AutoHolder function not being activated, the actual driving speed being less than or equal to the crawl speed threshold, the brake pedal not being depressed, the handbrake not being activated, and the vehicle having no level 3 faults. No level 3 faults means the vehicle does not have any faults that affect normal driving. When the operating data meets the above preset conditions for entering crawl mode, it should be noted that multiple conditions must be met simultaneously for the VCU to determine that the vehicle has entered crawl mode and then initiate the calculation of crawl torque.

[0067] When calculating creep torque, the VCU dynamically adjusts based on the deviation between the vehicle's current actual speed and the preset target creep speed. The target creep speed can be preset according to the gear (for example, the target creep speed for forward gear is 3 km / h, and the target creep speed for reverse gear is 2 km / h), or the target creep speed can be the same as the creep speed threshold.

[0068] In one possible implementation, the VCU utilizes a speed-loop PI controller to perform proportional and integral calculations on the target creep speed and the actual driving speed to obtain the creep torque. The speed-loop PI controller can calculate the torque value used to eliminate speed deviations through a proportional-integral (PI) control algorithm. When the actual driving speed is lower than the target creep speed, a positive compensation torque is output to increase power; when the actual driving speed is higher than the target creep speed, the creep torque is gradually reduced, causing the vehicle to exit creep mode. If the two tend to be consistent, the current creep torque is maintained stable. This embodiment of the application ensures that the creep torque can dynamically adapt to actual operating conditions through closed-loop control, making the actual vehicle speed approach the target creep speed.

[0069] For ease of understanding, combined with Figure 2 First, let's introduce the speed loop PI controller. For example... Figure 2 As shown, Figure 2 This is a schematic diagram of a speed loop PI controller provided in an embodiment of this application.

[0070] The target creep speed and the actual speed are input into the speed loop PI controller. The speed loop PI controller performs proportional calculations on the target creep speed and the actual speed, and simultaneously performs integral calculations on the target creep speed and the actual speed. Finally, the creep torque is determined based on the results of the proportional calculation and the integral calculation.

[0071] The target creep speed and the actual driving speed are used as inputs to the speed loop PI controller. In the speed loop PI controller, the difference between the target creep speed and the actual driving speed is first calculated, i.e., speed difference = target creep speed - actual driving speed. The speed difference is the core basis for subsequent proportional and integral calculations, reflecting the degree of deviation between the vehicle's actual speed and the target speed.

[0072] The integral calculation process and the proportional calculation process are described below with reference to the accompanying diagrams.

[0073] During the integral calculation process, the integral torque (first torque) is calculated in two scenarios based on the vehicle brake pedal state (VCU_BrakerPedalState).

[0074] A fixed integral coefficient (Ki) is unsuitable for braking scenarios, causing the integral to not clear quickly to zero during braking, resulting in residual creep torque and potential safety hazards. This application's embodiment detects the brake pedal state (VCU_BrakerPedalState) in real time and switches between two sets of integral coefficients (Ki).

[0075] When the brake pedal is detected to be depressed, the speed loop PI controller uses a larger first integral coefficient Ki1, and performs integral calculation based on the speed difference: First torque (brake depressed) = ∫(speed difference × Ki1)dt. Using a first integral coefficient Ki1, which is larger than the second integral coefficient Ki2, accelerates the integral value to zero, ensuring the creep torque quickly returns to 0. When the brake pedal is not depressed, the speed loop PI controller uses a second integral coefficient Ki2, and performs integral calculation based on the speed difference: First torque (brake not depressed) = ∫(speed difference × Ki2)dt. This adapts to the steady-state control requirements of normal creep.

[0076] In traditional speed loop PI controllers, the integral accumulation may result in a negative value, leading to negative torque output when the vehicle is creeping forward (the vehicle tends to reverse, conflicting with the creeping intention), or the inability to effectively eliminate deviations when the vehicle speed is higher than the target. The speed loop PI controller provided in this application forcibly limits the integral accumulation value to ≥0 during the integral calculation process.

[0077] When the speed difference is negative (actual driving speed is greater than the target creep speed), if the accumulated integral value tends to be negative, the accumulation stops or is reset to 0. When the speed difference is positive (actual driving speed is less than the target creep speed), the integral is accumulated normally to ensure that the torque direction is always positive when creeping in forward gear, and that the integral can be reduced to zero and return to steady state when the vehicle speed is too high.

[0078] Furthermore, continuous integral accumulation may lead to integral saturation, resulting in torque overshoot and loss of control. Even if the speed deviation is eliminated, the integral value remains high, causing the vehicle to accelerate continuously. The speed loop PI controller provided in this application triggers integral saturation protection during integral calculation if the accumulated integral value reaches the maximum creep torque limit. This means the Ki_Saturation signal is 1, stopping integral accumulation to prevent excessive torque exceeding the vehicle's safe control range. When Ki_Saturation is 0, integral accumulation continues. This prevents unlimited integral growth leading to torque overshoot and retains the flexibility for subsequent recoverable accumulation when a deviation exists, ensuring control accuracy.

[0079] During the proportional calculation process, the speed loop PI controller directly performs proportional calculations based on the speed difference and the proportional coefficient kp to obtain the second torque coefficient. The second torque = speed difference × kp. This step amplifies the impact of speed deviation on torque through the proportional coefficient, enabling rapid response to speed changes and achieving a control effect of quick compensation when deviations are large.

[0080] Finally, the first torque (integral calculation result) and the second torque (proportional calculation result) are added together to obtain the final creep torque: Creep torque = first torque + second torque.

[0081] The PI calculation result may exceed the vehicle's physical limits (such as the maximum output limit of the motor) due to integral saturation, excessively large proportional coefficients, etc. This application's embodiment, after superimposing the proportional torque and integral torque, forcibly limits the final output to ≤ the maximum creep torque limit. If the superimposed value exceeds the limit, it is truncated to the maximum creep torque limit, ensuring that the vehicle's power does not exceed the limit and avoiding the risk of loss of control.

[0082] The speed loop PI controller provided in this application not only retains the advantages of traditional PI control in eliminating steady-state errors and responding quickly to deviations, but also specifically addresses the special needs of electric vehicle creep scenarios (such as direction control, braking safety, torque over-limit, etc.), achieving more precise and safer creep torque control.

[0083] S103: The VCU combines the creep torque with the vehicle's drive pedal torque to control the vehicle's actual driving speed to approach the target creep speed.

[0084] The VCU linearly superimposes the drive pedal torque and the optimized creep torque, representing the driver's active acceleration demand and the system's compensation demand to maintain the target creep speed, respectively. The superposition is cut off when braking is triggered to ensure safety. The superimposed total torque acts on the powertrain, and the actual driving speed is fed back to the control closed loop. When the actual driving speed is lower than the target creep speed, the creep torque is increased; when the actual driving speed is higher than the target creep speed, the creep torque is reduced by integral limiting, dynamically adapting to scenarios such as flat ground and uphill driving, and also accommodating the driver's active acceleration with light throttle input.

[0085] Compared to traditional torque gauge switching methods, this superposition method avoids abrupt torque changes, eliminates mode switching jitter, and achieves a smooth transition. Through speed closed-loop and dynamic compensation, it can accurately adapt to complex working conditions such as inclines, controlling the actual driving speed to approach the target creep speed. At the same time, it integrates driver intentions with automatic system control, and is compatible with operations such as light accelerator pedal pressing, allowing the vehicle to operate stably in different scenarios, improving the creep experience and safety, and solving the problems of poor connection, low accuracy, and weak scenario adaptability of traditional solutions.

[0086] In one possible implementation, such as Figure 3 As shown, the control method further includes step S104.

[0087] S104: If the running data meets the preset conditions for exiting the crawl mode, the VCU will exit the crawl mode using the first, second, or third method based on the running data.

[0088] The speed at which the first method exits the crawling mode is greater than the speed at which the second method exits the crawling mode, and the speed at which the second method exits the crawling mode is greater than the speed at which the third method exits the crawling mode.

[0089] When the vehicle meets the preset conditions for exiting crawl mode, the VCU selects one of three exit methods (first, second, and third) based on operational data, with the exit speeds of the three methods exhibiting a gradient difference. This tiered exit strategy ensures both rapid response in emergency exit scenarios and smoothness requirements for regular exit scenarios.

[0090] In this embodiment, the preset conditions for exiting the crawl mode include the vehicle exiting the preparation mode, the vehicle being in parking or neutral, the vehicle's automatic parking function being activated, the vehicle speed being greater than the crawl speed threshold, the vehicle's brake pedal being pressed, or the vehicle having a malfunction that affects normal driving.

[0091] In one possible implementation, the process of the VCU controlling the vehicle to exit crawl mode may include:

[0092] If the vehicle exits the preparation mode, the vehicle is in parking or neutral, the vehicle's auto hold function is activated, or the vehicle has a malfunction that affects normal driving, the first method should be used to exit the crawl mode.

[0093] If the vehicle's brake pedal is depressed, exit crawl mode using the second method.

[0094] If the vehicle speed exceeds the creep speed threshold, a third method will be used to exit creep mode.

[0095] The VCU controls the vehicle's exit from crawl mode using a tiered strategy based on different exit trigger conditions. The exit speed decreases sequentially for the three methods, as detailed below:

[0096] When the operating data meets any of the following preset conditions, the VCU determines that an emergency or forced exit from crawl mode is required, and adopts the first method (fastest exit speed): such as the vehicle exiting the preparation mode (power system not ready), the gear shifting to parking or neutral, the automatic parking function being activated (the vehicle must be locked and stationary), or the vehicle having a malfunction affecting normal driving (such as power system abnormality, braking failure, etc.). In this case, the VCU controls the vehicle to quickly exit crawl mode.

[0097] When the brake pedal is detected to be depressed, the driver actively intervenes in the vehicle's state by braking. The VCU gradually reduces the creep torque (instead of immediately returning it to zero), allowing the creep torque to exit smoothly with the braking process, avoiding a sudden torque change that conflicts with the braking action and reducing vehicle body impact.

[0098] When the vehicle speed is detected to be greater than the creep speed threshold, the vehicle has already exceeded the creep speed range due to driver acceleration or inertia. The VCU uses the integral limiting logic of the speed loop PI controller (such as gradually reducing the integral accumulation to 0) to slowly reduce the creep torque to 0, achieving a smooth transition from creep mode to normal driving mode without obvious torque drop.

[0099] Through the above process, this application embodiment employs a first method for rapid exit in emergency scenarios such as malfunctions and gear shifting, avoiding conflicts between the creep function and safety requirements. For conventional scenarios such as braking or exceeding speed limits, exit is achieved at medium and slow speeds respectively, eliminating the abruptness of mode switching through gradual torque changes (e.g., avoiding the conflict between creep torque and braking force during braking, and avoiding power interruption caused by a sudden loss of torque during acceleration). This ensures that the creep mode exit logic responds to safety priorities while also aligning with the driver's operational intentions, enhancing the intelligence and user-friendliness of creep control.

[0100] As an example, when emergency conditions such as "vehicle exiting preparation mode, gear being in P / N gear, AutoHold being activated, or a fault affecting driving" are triggered, the first method achieves rapid exit by directly cutting off the torque source and clearing the residual integral value. When the VCU exits the creep mode using the first method, it forcibly sets the creep torque output by the speed loop PI controller to 0, directly terminating the torque superposition logic; simultaneously, it clears the first torque accumulated in the integral term of the speed loop PI controller to zero, that is, resets the accumulated integral value to 0.

[0101] In emergency scenarios, the creep intervention needs to be lifted immediately. The torque output of the speed loop PI controller is set to zero to ensure that the creep torque output is cut off instantly. The integral accumulation value is also cleared to prevent torque sudden changes caused by residual integral values ​​when re-entering creep mode (e.g., when creep is restarted after the fault is cleared, there is no historical integral interference), thus achieving the safety effect of stopping and clearing immediately.

[0102] As another example, when the brake pedal is depressed, the second method guides a smooth exit by adjusting the target value to allow the torque to decay naturally. When the VCU exits creep mode using the second method, it forcibly sets the target creep speed input to the speed loop PI controller to 0, gradually reducing the creep torque to zero through the speed loop PI controller. When the driver actively brakes to decelerate, there is no need for emergency cutoff, but it is necessary to avoid the creep torque from opposing the braking force. After the target creep speed is set to 0, the speed difference becomes the negative actual driving speed. Combined with the improved logic of the speed loop PI controller (integral accumulation ≥ 0, integral does not increase when the difference is negative), the proportional term outputs a reverse torque suppression due to the negative difference, and the integral term stops accumulating due to the negative difference and gradually returns to zero. The two work together to allow the creep torque to gradually decrease from the current value to 0, which both responds to the braking intention and avoids the body impact caused by sudden torque changes (such as the nose-diving phenomenon caused by the sudden disappearance of creep torque during braking).

[0103] As another example, when the actual driving speed exceeds the creep speed threshold, the third method maintains the target creep speed value and naturally exits based on feedback from the actual driving speed. When the actual driving speed exceeds the creep speed threshold, the vehicle has exceeded the speed range of the creep mode due to driver acceleration or inertia. The target creep speed of the input speed loop PI controller remains unchanged, and the speed difference is negative. The proportional term outputs negative torque, and the integral term stops accumulating due to the negative difference. The original integral value naturally decays to 0 over time, and finally the creep torque slowly returns to zero from the current value, achieving a seamless transition from creep mode to normal drive (e.g., when the driver continues to accelerate, the creep torque gradually exits without any sense of power interruption).

[0104] This application employs three methods for different exit scenarios, achieving a harmonious balance between safety, smoothness, and scenario adaptability through precise matching of trigger conditions and exit logic. In emergency scenarios such as malfunctions or gear shifts, the first method directly resets the creep torque and integral term for rapid exit, eliminating safety risks. For braking scenarios, the second method sets the target creep speed to 0 to guide a smooth torque decay, avoiding impact caused by the conflict between creep torque and braking force. For natural transition scenarios involving exceeding vehicle speed limits, the third method maintains the target speed constant, allowing the creep torque to naturally return to zero with the integral term, achieving a seamless transition from creep to normal driving. These three methods provide a gradient adaptation from emergency to normal scenarios, ensuring safety priority while eliminating the abruptness of mode switching through gradual torque changes, making the creep mode exit logic more intelligent and more aligned with actual driving needs.

[0105] Based on the above embodiments, this application also provides a vehicle crawl control device, which includes:

[0106] The acquisition module is used to acquire vehicle operating data;

[0107] The determination module is used to determine the creep torque based on the actual driving speed of the vehicle and the target creep speed of the vehicle when the operating data meets the preset conditions for entering the creep mode;

[0108] The control module is used to superimpose the creep torque and the drive pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target creep speed.

[0109] In one possible implementation, a determining module is specifically used to perform proportional and integral calculations on the target creep speed and the actual driving speed using a speed loop PI controller to obtain the creep torque.

[0110] In one possible implementation, the determining module is specifically configured to determine the speed difference obtained by subtracting the actual driving speed from the target creep speed; when the vehicle's brake pedal is depressed, to calculate a first torque by integrating the speed difference and a first integral coefficient; when the vehicle's brake pedal is not depressed, to calculate the first torque by integrating the speed difference and a second integral coefficient; to obtain a second torque by integrating the speed difference and a proportional coefficient; and to sum the first torque and the second torque to obtain the creep torque.

[0111] In one possible implementation, the determining module is further configured to stop the integral accumulation when the cumulative integral value is greater than or equal to the maximum creep torque during the integral calculation based on the speed difference.

[0112] In one possible implementation, the control module is further configured to exit the crawling mode by adopting a first method, a second method, or a third method based on the running data when the running data meets the preset conditions for exiting the crawling mode; wherein, the speed of exiting the crawling mode by adopting the first method is greater than the speed of exiting the crawling mode by adopting the second method, and the speed of exiting the crawling mode by adopting the second method is greater than the speed of exiting the crawling mode by adopting the third method.

[0113] In one possible implementation, the preset conditions for exiting the crawl mode include: the vehicle exiting the preparation mode; the vehicle being in parking or neutral; the vehicle's automatic parking function being activated; the vehicle's speed exceeding the crawl speed threshold; the vehicle's brake pedal being depressed; and the vehicle having a malfunction that affects its normal operation.

[0114] In one possible implementation, the control module is specifically configured to exit the creep mode in the following situations: when the vehicle exits the preparation mode, the vehicle is in parking or neutral, the vehicle's automatic parking function is activated, or the vehicle has a malfunction that affects normal driving; exit the creep mode in the following situation: when the vehicle's brake pedal is depressed; and exit the creep mode in the following situation: when the vehicle's speed exceeds the creep speed threshold.

[0115] In one possible implementation, the control module exits the creep mode using the first method, specifically including:

[0116] Set the creep torque output by the speed loop PI controller to 0, and set the first torque obtained by accumulating the integral term in the speed loop PI controller to 0;

[0117] The control module exits the creep mode using the second method, specifically including:

[0118] Set the target creep speed input to the speed loop PI controller to 0;

[0119] The control module exits the creep mode using the third method, specifically including:

[0120] The target creeping speed input to the speed loop PI controller remains constant.

[0121] In one possible implementation, this application also provides a control device.

[0122] The control device may include memory and a processor. The memory may be random access memory (RAM), flash memory, read-only memory (ROM), EPROM, non-volatile read-only memory (Electronic Programmable ROM), registers, hard disk, removable disk, etc.

[0123] The memory can store computer instructions, which, when executed by a processor, can be used in a vehicle crawl control method. The memory can also store data, such as preset ranges and preset thresholds as described in the above embodiments.

[0124] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape) or a semiconductor medium (e.g., solid-state disk (SSD)).

[0125] This application also provides a readable storage medium for storing the methods provided in the above embodiments. Examples include random access memory (RAM), flash memory, read-only memory (ROM), EPROM, non-volatile read-only memory (EEPROM), registers, hard disks, removable disks, or any other form of storage medium in the art.

[0126] In the embodiments of this application, the terms "first" and "second" (if they exist) are used only as name identifiers and do not represent the order of first and second.

[0127] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Regarding the methods disclosed in the embodiments, since they correspond to the product embodiments disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the description of the product embodiments.

[0128] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling vehicle crawling, characterized in that, The method includes: Obtain vehicle operating data; When the operating data meets the preset conditions for entering the crawl mode, the crawl torque is determined based on the actual driving speed of the vehicle and the target crawl speed of the vehicle; The creep torque and the vehicle's drive pedal torque are superimposed to control the vehicle's actual driving speed to approach the target creep speed; Determining the creep torque based on the vehicle's actual driving speed and the vehicle's target creep speed includes: The creep torque is obtained by performing proportional and integral calculations on the target creep speed and the actual driving speed using a speed loop PI controller. The creep torque is obtained by proportional and integral calculations of the target creep speed and the actual driving speed using a speed loop PI controller, including: Determine the speed difference obtained by subtracting the actual travel speed from the target creep speed; When the vehicle's brake pedal is depressed, the first torque is calculated by integrating the speed difference and the first integral coefficient; when the vehicle's brake pedal is not depressed, the first torque is calculated by integrating the speed difference and the second integral coefficient. The second torque is obtained based on the speed difference and the proportional coefficient; The creeping torque is obtained by adding the first torque and the second torque.

2. The method according to claim 1, characterized in that, The method further includes stopping the integral accumulation when the cumulative integral value is greater than or equal to the maximum creep torque value during the integral calculation based on the speed difference.

3. The method according to claim 1, characterized in that, The method further includes: If the running data meets the preset conditions for exiting the crawl mode, the crawl mode is exited using a first method, a second method, or a third method based on the running data; wherein, the speed of exiting the crawl mode using the first method is greater than the speed of exiting the crawl mode using the second method, and the speed of exiting the crawl mode using the second method is greater than the speed of exiting the crawl mode using the third method.

4. The method according to claim 3, characterized in that, The preset conditions for exiting the crawl mode include: The vehicle exits the preparation mode; the vehicle is in parking or neutral; the vehicle's automatic parking function is activated; the vehicle's speed exceeds the creep speed threshold; the vehicle's brake pedal is depressed; the vehicle has a malfunction that affects its normal operation.

5. The method according to claim 4, characterized in that, When the running data meets the preset conditions for exiting the crawl mode, the step of exiting the crawl mode using a first method, a second method, or a third method based on the running data includes: If the vehicle exits the preparation mode, the vehicle is in parking or neutral, the vehicle's automatic parking function is activated, or the vehicle has a malfunction that affects normal driving, the first method shall be used to exit the crawl mode. When the vehicle's brake pedal is depressed, exit the crawl mode using the second method; If the vehicle speed exceeds the creep speed threshold, the third method is used to exit the creep mode.

6. The method according to any one of claims 3-5, characterized in that, Exiting the crawl mode using the first method includes: Set the creep torque output by the speed loop PI controller to 0, and set the first torque obtained by accumulating the integral term in the speed loop PI controller to 0; Exiting the crawl mode using the second method includes: Set the target creep speed input to the speed loop PI controller to 0; Exiting the crawl mode using the third method includes: The target creeping speed input to the speed loop PI controller remains constant.

7. A control device, characterized in that, It includes a processor and a memory, the memory being used to store programs, instructions, or code, and the processor being used to execute the programs, instructions, or code in the memory to perform the vehicle crawl control method as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The system contains a computer program that is loaded by a processor to execute the vehicle crawl control method as described in any one of claims 1-6.

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