Automobile crawling control method and related device

Abstract

The invention discloses an automobile crawling control method and a related device. According to the method, the operation data of the vehicle are obtained, when the crawling condition is met, the crawling torque is dynamically determined based on the actual running speed and the target crawling speed, and then the crawling torque and the driving pedal torque are output in a superposed mode. The vehicle is controlled in the mode that the creeping torque and the driving pedal torque are overlapped, and smooth transition from a normal running mode to a creeping mode is achieved. According to the method, closed-loop control is constructed through dynamic torque adjustment, the control precision of the crawling speed is improved, and the smoothness, accuracy and scene adaptation capacity of the crawling process of the electric vehicle are effectively optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile control, in particular to an automobile crawling control method and related device. BACKGROUND

[0002] Automobile crawling refers to the slow movement of a vehicle without stepping on the drive pedal. Automobile crawling is often used in scenes of low-speed operation such as congested following, slope anti-slip and low-speed moving.

[0003] The crawling of traditional fuel vehicles relies on engine idle speed, which may be accompanied by slight shaking or jerk. The crawling of electric vehicles is mostly directly driven by the motor, which is smoother and adjustable.

[0004] However, there is still some shaking when the electric vehicle enters and exits the crawling mode, resulting in poor user experience. SUMMARY

[0005] Based on the above problems, the present application provides a method.

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

[0007] In a first aspect, the embodiments of the present application disclose an automobile crawling control method, characterized in that the method comprises:

[0008] obtaining running data of a vehicle;

[0009] in a case where the running data meets a preset condition for entering a crawling mode, determining a crawling torque according to an actual driving speed of the vehicle and a target crawling speed of the vehicle;

[0010] superimposing the crawling torque and a drive pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target crawling speed.

[0011] In a possible implementation manner, the determination of the crawling torque according to the actual driving speed of the vehicle and the target crawling speed of the vehicle comprises:

[0012] performing proportional calculation and integral calculation on the target crawling speed and the actual driving speed by using a speed loop PI controller to obtain the crawling torque.

[0013] In a possible implementation manner, the proportional calculation and integral calculation on the target crawling speed and the actual driving speed by using the speed loop PI controller to obtain the crawling torque comprise:

[0014] determining a speed difference value obtained by subtracting the actual driving speed from the target crawling speed;

[0015] In a case where the brake pedal of the vehicle is stepped on, a first torque is calculated by integrating the speed difference value and a first integral coefficient; in a case where the brake pedal of the vehicle is not stepped on, a first torque is calculated by integrating the speed difference value and a second integral coefficient;

[0016] A second torque is obtained according to the speed difference value and a proportional coefficient;

[0017] The first torque and the second torque are added to obtain the crawling torque.

[0018] In a possible implementation, the method further includes, in the process of calculating the integral value according to the speed difference value, stopping the integral accumulation when the integral accumulation value is greater than or equal to a maximum limit value of the crawling torque.

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

[0020] In a case where the running data meets preset conditions for exiting the crawling mode, the crawling mode is exited in a first mode, a second mode or a third mode according to the running data; a speed of exiting the crawling mode in the first mode is greater than a speed of exiting the crawling mode in the second mode, and the speed of exiting the crawling mode in the second mode is greater than a speed of exiting the crawling mode in the third mode.

[0021] In a possible implementation, the preset conditions for exiting the crawling mode include:

[0022] The vehicle exits a preparation mode; a gear of the vehicle is in a parking gear or a neutral gear; an automatic parking function of the vehicle is activated; a vehicle speed of the vehicle is greater than a crawling speed threshold; a brake pedal of the vehicle is stepped on; and the vehicle has a fault affecting normal driving of the vehicle.

[0023] In a possible implementation, the crawling mode is exited in the first mode, the second mode or the third mode according to the running data in a case where the running data meets the preset conditions for exiting the crawling mode, including:

[0024] In a case where the vehicle exits the preparation mode, the gear of the vehicle is in the parking gear or the neutral gear, the automatic parking function of the vehicle is activated or the vehicle has the fault affecting the normal driving of the vehicle, the crawling mode is exited in the first mode;

[0025] In a case where the brake pedal of the vehicle is stepped on, the crawling mode is exited in the second mode;

[0026] In a case where the vehicle speed of the vehicle is greater than the crawling speed threshold, the crawling mode is exited in the third mode.

[0027] In a possible implementation, the first mode is adopted to exit the crawling mode, including:

[0028] The crawling torque output by a speed loop PI controller is set to 0, and a first torque accumulated by an integral term in the speed loop PI controller is set to 0;

[0029] The second mode is adopted to exit the crawling mode, including:

[0030] The target crawling speed input into the speed loop PI controller is set to 0;

[0031] The third mode is adopted to exit the crawling mode, including:

[0032] The target crawling speed input into the speed loop PI controller is kept unchanged.

[0033] In a second aspect, the embodiments of the present application disclose a vehicle crawling control device, which comprises:

[0034] An acquisition module is configured to acquire running data of a vehicle;

[0035] A determination module is configured to determine a crawling torque according to an actual driving speed of the vehicle and a target crawling speed of the vehicle when the running data meets preset conditions for entering a crawling mode;

[0036] A control module is configured to superimpose the crawling torque and a drive pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target crawling speed.

[0037] In a possible implementation, the determination module is specifically configured to use a speed loop PI controller to perform proportional calculation and integral calculation on the target crawling speed and the actual driving speed to obtain the crawling torque.

[0038] In a possible implementation, the determination module is specifically configured to determine a speed difference value obtained by subtracting the actual driving speed from the target crawling speed; when a brake pedal of the vehicle is stepped on, perform integral calculation on the speed difference value and a first integral coefficient to obtain a first torque; when the brake pedal of the vehicle is not stepped on, perform integral calculation on the speed difference value and a second integral coefficient to obtain a first torque; obtain a second torque according to the speed difference value and a proportional coefficient; and add the first torque and the second torque to obtain the crawling torque.

[0039] In a possible implementation, the determining module is further configured to, in the process of integral calculation according to the speed difference, stop the integral accumulation when the integral accumulation is greater than or equal to the maximum value of the creep torque.

[0040] In a possible implementation, the control module is further configured to, in the case where the running data satisfies a preset condition for exiting the creep mode, exit the creep mode in a first mode, a second mode or a third mode according to the running data; the speed of exiting the creep mode in the first mode is greater than the speed of exiting the creep mode in the second mode, and the speed of exiting the creep mode in the second mode is greater than the speed of exiting the creep mode in the third mode.

[0041] In a possible implementation, the preset condition for exiting the creep mode includes that the vehicle exits a preparation mode, a gear of the vehicle is in a parking gear or a neutral gear, an automatic parking function of the vehicle is activated, a vehicle speed of the vehicle is greater than a creep speed threshold, a brake pedal of the vehicle is depressed, or the vehicle has a fault affecting normal driving of the vehicle.

[0042] In a possible implementation, the control module is specifically configured to, in the case where the vehicle exits the preparation mode, the gear of the vehicle is in the parking gear or the neutral gear, the automatic parking function of the vehicle is activated, or the vehicle has the fault affecting the normal driving of the vehicle, exit the creep mode in the first mode; in the case where the brake pedal of the vehicle is depressed, exit the creep mode in the second mode; and in the case where the vehicle speed of the vehicle is greater than the creep speed threshold, exit the creep mode in the third mode.

[0043] In a possible implementation, the control module exits the creep mode in the first mode, and specifically includes:

[0044] a creep torque output by a speed loop PI controller is set to 0, and a first torque accumulated by an integral term in the speed loop PI controller is set to 0;

[0045] the control module exits the creep mode in the second mode, and specifically includes:

[0046] the target creep speed input into the speed loop PI controller is set to 0;

[0047] the control module exits the creep mode in the third mode, and specifically includes:

[0048] the target creep speed input into the speed loop PI controller is kept unchanged.

[0049] In a third aspect, the embodiments of the present application disclose a control device, comprising a processor and a memory, the memory being used for storing programs, instructions or codes, and the processor being used for executing the programs, instructions or codes in the memory to complete the vehicle crawling control method according to any one of the first aspect.

[0050] In a fourth aspect, the embodiments of the present application disclose a computer readable storage medium, storing a computer program, the computer program being loaded by a processor to execute the vehicle crawling control method according to any one of the first aspect.

[0051] The embodiments of the present application disclose a vehicle crawling control method and related devices. The method acquires vehicle running data and dynamically determines a crawling torque based on an actual driving speed and a target crawling speed when a crawling condition is met, and then superimposes and outputs the crawling torque and a driving pedal torque. The vehicle is controlled by superimposing the crawling torque and the driving pedal torque, so that a smooth transition from normal driving to crawling mode is realized. The method constructs a closed-loop control through dynamic torque adjustment, improves the control accuracy of the crawling speed, and effectively optimizes the smoothness, accuracy and scene adaptation capability of the electric vehicle crawling process. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0053] Figure 1 A flowchart of a vehicle crawling control method provided by the embodiments of the present application is shown in the figure.

[0054] Figure 2 A schematic diagram of a speed loop PI controller provided by the embodiments of the present application is shown in the figure.

[0055] Figure 3 A flowchart of another vehicle crawling control method provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0056] At present, the entering and exiting of the electric vehicle into the crawling mode is realized by switch control. When the vehicle needs to enter the crawling mode, the vehicle is controlled by the torque table corresponding to the crawling mode; when the vehicle needs to exit the crawling mode, the vehicle is controlled by the torque table corresponding to the normal driving mode. However, the torque table switching when entering or exiting the crawling mode will cause 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] The actual driving speed refers to the current driving speed of the vehicle monitored in real time by a vehicle speed sensor, and is used to determine whether the vehicle is in a low-speed state and adjust the crawling torque. The gear signal is used to reflect the current gear of the vehicle, and the gears of the vehicle include drive (D), reverse (R), neutral (N) and parking (P). The vehicle preparation signal is used to indicate whether the vehicle power system is ready. The drive pedal signal is used to indicate the depth of the drive pedal, which can be obtained by a pedal position sensor, and is used to determine whether the driver has an active acceleration intention. The brake pedal signal is used to reflect the depth of the brake pedal, and if it is in a braking state, it usually does not meet the conditions for entering the crawling mode. The hand brake signal is used to indicate the state signal of the parking brake, and the vehicle cannot enter the crawling mode when the hand brake is activated. The vehicle fault level is used to represent the fault state of each system of the vehicle (such as the power system and the braking system), and if the fault level reaches a threshold affecting driving safety, the crawling mode will be limited. The automatic parking activation state is used to indicate whether the AutoHold function is activated, and the vehicle is in a stationary locking state when the AutoHold is activated, and needs to be released before entering the crawling mode.

[0064] The running data is constructed from the vehicle power state, the driver's operation intention, and the safety state, etc. to form a complete portrait of the vehicle operation, providing comprehensive and real-time input basis for subsequent crawling mode judgment and control.

[0065] S102: When the running data meets the preset conditions for entering the crawling mode, the VCU determines the crawling torque according to the actual driving speed of the vehicle and the target crawling speed of the vehicle.

[0066] The preset conditions for entering the crawling mode are used to measure whether the current vehicle needs or can enter the crawling mode. As an example, the preset conditions for entering the crawling mode can include that the vehicle preparation signal indicates that the vehicle is in a preparation mode, the gear of the vehicle is in a drive or reverse gear, the AutoHold function is not activated, the actual driving speed is less than or equal to the crawling speed threshold, the brake pedal is not stepped on, the hand brake is not activated, and the vehicle has no level three fault. The vehicle has no level three fault means that the vehicle has no fault affecting normal driving of the vehicle. When the running data meets the above-mentioned preset conditions for entering the crawling mode, it needs to be noted that the running data needs to meet the above-mentioned multiple conditions at the same time, and the VCU determines that the vehicle enters the crawling mode, and then starts the calculation of the crawling torque.

[0067] When calculating the creep torque, the VCU dynamically adjusts based on the deviation between the current actual driving speed of the vehicle and the preset target creep speed. The target creep speed can be preset according to the gear position (for example, the target creep speed corresponding to the forward gear is 3 km / h, and the target creep speed corresponding to the 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 uses a speed loop PI controller to proportionally and integrally calculate the target creep speed and the actual driving speed to obtain the creep torque. The speed loop PI controller can calculate a torque value for eliminating the speed deviation 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 the power; when the actual driving speed is higher than the target creep speed, the creep torque is gradually reduced to make the vehicle exit the creep mode. If the two tend to be consistent, the current creep torque is maintained stable. The embodiments of the present application ensure that the creep torque can be dynamically adapted to the actual working condition through closed-loop control, so that the actual driving speed of the vehicle tends to the target creep speed.

[0069] For ease of understanding, the embodiments of the present application will be described below in conjunction with Figure 2 First, the speed loop PI controller will be introduced. As shown in Figure 2 , Fig. 1 is a schematic diagram of a speed loop PI controller provided by an embodiment of the present application. Figure 2

[0070] The target creep speed and the actual driving speed are input into the speed loop PI controller. The speed loop PI controller proportionally calculates the target creep speed and the actual driving speed, and integrally calculates the target creep speed and the actual driving speed, and finally determines the creep torque according to the results of the proportional calculation and the integral calculation.

[0071] The target creep speed and the actual driving speed are input into the speed loop PI controller. The speed loop PI controller proportionally calculates the target creep speed and the actual driving speed, and integrally calculates the target creep speed and the actual driving speed, and finally determines the creep torque according to the results of the proportional calculation and the integral calculation.

[0072] The integral calculation process and the proportional calculation process will be introduced below in conjunction with the accompanying drawings.

[0073] In the integral calculation process, the integral torque (the first torque) is calculated according to the vehicle brake pedal state (VCU_BrakerPedalState) in two scenarios.

[0074] ​The fixed integral coefficient (Ki) cannot adapt to the brake scene, resulting in that the integral cannot be quickly cleared when braking, and the residual creep torque causes safety hazards. The embodiments of the present application detect the brake pedal state (VCU_BrakerPedalState) in real time, and switch two sets of integral coefficients (Ki).

[0075] When it is detected that the vehicle brake pedal is stepped on, the speed loop PI controller calls a larger first integral coefficient Ki1, and integrates the speed difference value to calculate the first torque (brake stepped on): first torque (brake stepped on) = ∫(speed difference value × Ki1)dt. The first integral coefficient Ki1 greater than the second integral coefficient Ki2 can accelerate the integral value to zero, ensuring that the creep torque quickly returns to zero. When the brake pedal is not stepped on, the speed loop PI controller calls the second integral coefficient Ki2, and integrates the speed difference value to calculate the first torque (brake not stepped on): first torque (brake not stepped on) = ∫(speed difference value × Ki2)dt. Adapt to the steady-state control requirement of normal creep.

[0076] In the traditional speed loop PI controller, the integral accumulation may be negative, resulting in that a negative torque is output when the vehicle is creeping forward (the vehicle has a tendency to reverse, which conflicts with the intention of creeping), or the deviation cannot be effectively eliminated when the vehicle speed is higher than the target. The speed loop PI controller provided by the embodiments of the present application forcibly limits the integral accumulation value to be greater than or equal to 0 during the integral calculation process.

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

[0078] In addition, continuous integral accumulation may cause integral saturation, torque overshoot out of control, and even if the speed deviation is eliminated, the integral value still maintains a high level, causing the vehicle to continue to accelerate. The speed loop PI controller provided by the embodiments of the present application triggers integral saturation protection if the integral accumulation value reaches the maximum limit of the creep torque during the integral calculation process, that is, the Ki_Saturation signal is 1, the integral accumulation is stopped, and the torque is prevented from being too large to exceed the safety range of vehicle control. When Ki_Saturation is 0, the integral accumulation continues. This prevents the integral from increasing indefinitely, and preserves the flexibility of subsequent recoverable accumulation when the deviation exists, ensuring control accuracy.

[0079] In the proportional calculation process, the speed loop PI controller directly performs proportional calculation according to the speed difference value and the proportional coefficient kp to obtain the second torque coefficient. The second torque = speed difference value × kp. This step amplifies the influence of the speed deviation on the torque through the proportional coefficient, quickly responds to the speed change, and realizes the control effect of quickly compensating for the deviation.

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

[0081] The PI calculation result may cause the torque to exceed the physical limit of the vehicle (such as the maximum output limit of the motor) due to integral saturation, excessively large proportional coefficient, etc. After the proportional torque and the integral torque are superimposed, the embodiment of the present application forcibly limits the final output ≤ 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 power does not exceed the limit and avoiding the risk of losing control.

[0082] The speed loop PI controller provided by the embodiment of the present application not only retains the advantages of traditional PI control in eliminating steady-state error and fast response deviation, but also specifically solves the special needs of electric vehicle creep scenarios (such as direction control, brake safety, torque overrun, etc.), achieving more accurate and safer creep torque control.

[0083] S103: The VCU superimposes 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.

[0084] The VCU linearly superimposes the drive pedal torque and the optimized creep torque, which respectively represent the driver's active acceleration demand and the system's compensation demand for maintaining the target creep speed. When the brake is triggered, the superposition is cut off to ensure safety. The total torque after superposition 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, and when the actual driving speed is higher than the target creep speed, the creep torque is reduced by integral limitation, dynamically adapting to flat, uphill, etc. scenes, and also compatible with the driver's active acceleration of light stepping on the accelerator.

[0085] Compared with the traditional torque table switching scheme, this superimposition method avoids torque step changes, eliminates mode switching jitter, and realizes smooth transition. Through speed closed loop and dynamic compensation, it can accurately adapt to complex conditions such as slope, control the actual driving speed to approach the target creep speed. At the same time, the driver's intention and system automatic control are integrated, compatible with light stepping on the accelerator and other operations, allowing the vehicle to run stably in different scenarios, improving the creep experience and safety, and solving the problems of poor connection, low precision, and weak scene adaptation of traditional schemes.

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

[0087] S104: The VCU exits the creep mode according to the running data in the case that the running data meets the preset condition for exiting the creep mode.

[0088] The speed of adopting the first mode to exit the inching mode is greater than the speed of adopting the second mode to exit the inching mode, and the speed of adopting the second mode to exit the inching mode is greater than the speed of adopting the third mode to exit the inching mode.

[0089] When the vehicle meets the preset condition for exiting the inching mode, the VCU executes one of the first mode, the second mode and the third mode based on the running data, and the exit speeds of the three modes present gradient differences. Through the hierarchical exit strategy, the response speed of the emergency exit scene is ensured, and the smoothness requirement of the conventional exit scene is adapted.

[0090] In the embodiment of the application, the preset condition for exiting the inching mode includes that the vehicle is in a vehicle exit preparation mode, the gear of the vehicle is in a parking gear or a neutral gear, an automatic parking function of the vehicle is activated, the vehicle speed of the vehicle is greater than an inching speed threshold, the brake pedal of the vehicle is stepped on, or the vehicle has a fault affecting normal driving of the vehicle.

[0091] In a possible implementation, the process of the VCU controlling the vehicle to exit the inching mode can include:

[0092] In the case that the vehicle is in the vehicle exit preparation mode, the gear of the vehicle is in the parking gear or the neutral gear, the automatic parking function of the vehicle is activated, or the vehicle has the fault affecting the normal driving of the vehicle, the first mode is adopted to exit the inching mode;

[0093] In the case that the brake pedal of the vehicle is stepped on, the second mode is adopted to exit the inching mode;

[0094] In the case that the vehicle speed of the vehicle is greater than the inching speed threshold, the third mode is adopted to exit the inching mode.

[0095] The VCU controls the vehicle to exit the inching mode through the hierarchical strategy according to different exit trigger conditions, and the exit speeds of the three modes are sequentially decreased, and the specific logic is as follows:

[0096] When the running data meets any of the following preset conditions, the VCU determines that the inching mode needs to be exited urgently or forcibly, and the first mode (the fastest exit speed) is adopted. For example, the vehicle is in the vehicle exit preparation mode (the power system is not ready), the gear is switched to the parking gear or the neutral gear, the automatic parking function is activated (the vehicle needs to be locked and stationary), or the vehicle has a fault affecting normal driving (for example, an abnormal power system, a brake fault, etc.). At this time, the VCU controls the vehicle to quickly exit the inching mode.

[0097] When it is detected that the brake pedal of the vehicle is stepped on, the driver actively intervenes the vehicle state through braking at this time, the VCU gradually reduces the inching torque (rather than immediately returning to zero), so that the inching torque is smoothly exited with the braking process, avoiding the conflict between the torque mutation and the braking action, and reducing the impact on the vehicle body.

[0098] When the vehicle speed is detected to be greater than the crawling speed threshold value, at this time the vehicle has naturally exceeded the crawling speed range by the driver accelerating or inertia, the VCU makes the crawling torque slowly decay to 0 through the integral limiting logic of the speed loop PI controller (such as the integral accumulation gradually returns to 0), so as to realize smooth transition from the crawling mode to the normal driving mode without obvious torque fault.

[0099] Through the above process, the embodiments of the present application use the first mode to quickly exit in emergency scenes such as faults and gear switching, avoiding the conflict between the crawling function and the safety demand. For regular scenes such as brake depression and overspeed, the medium and slow exit are respectively adopted, and the jerk feeling of mode switching is eliminated through torque gradual change (such as avoiding the confrontation between the crawling torque and the braking force when braking, and avoiding the power interruption caused by the sudden disappearance of the torque when accelerating). The exit logic of the crawling mode not only responds to the safety priority, but also meets the driver's operation intention, thereby improving the intelligence and humanization of the crawling control.

[0100] As an example, when the emergency conditions such as the vehicle exit preparation mode, the gear being P / N gear, AutoHold being activated or there being a fault affecting driving are triggered, the first mode directly cuts off the torque source and clears the integral residual to realize quick exit. When the VCU adopts the first mode to exit the crawling mode, the VCU forcibly sets the crawling torque output by the speed loop PI controller to 0, directly terminates the torque superposition logic; and synchronously clears the first torque accumulated in the integral term of the speed loop PI controller, that is, resets the integral accumulation value to 0.

[0101] The emergency scene needs to immediately release the crawling intervention, the torque output by the speed loop PI controller is directly set to 0 to ensure that the crawling torque output is immediately cut off, and the integral accumulation value is cleared to avoid the residual integral value causing torque mutation when re-entering the crawling mode (such as restarting the crawling after the fault is removed without historical integral interference), thereby realizing the safety effect of stopping and clearing.

[0102] As another example, when the brake pedal is depressed, the second mode realizes smooth exit by adjusting the target value to guide the natural decay of the torque. When the VCU adopts the second mode to exit the crawling mode, the VCU forcibly sets the target crawling speed input into the speed loop PI controller to 0, and gradually reduces the crawling torque to zero through the speed loop PI controller. When the driver actively brakes to decelerate, the crawling torque needs to be avoided from confronting the braking force without being urgently cut off. After the target crawling speed is set to 0, the speed difference value becomes the negative actual driving speed. In combination with the improved logic of the speed loop PI controller (the integral accumulation ≥ 0, the integral does not increase when the difference is negative), the proportional term reversely suppresses the torque due to the negative difference, and the integral term stops accumulation and gradually returns to zero due to the negative difference, so that the crawling torque is gradually reduced to 0 from the current value, which not only responds to the braking intention, but also avoids the vehicle body impact caused by the sudden disappearance of the crawling torque when braking (such as the nod phenomenon caused by the sudden disappearance of the crawling torque when braking).

[0103] As another example, when the actual driving speed is greater than the crawling speed threshold, the third mode exits by maintaining the target crawling speed value and relying on the actual driving speed feedback. When the actual driving speed is greater than the crawling speed threshold, the vehicle has exceeded the speed range of the crawling mode due to driver acceleration or inertia, the target crawling speed of the input speed loop PI controller is kept unchanged, and the speed difference is negative. The proportional term outputs a negative torque, the integral term stops accumulating due to the negative difference, and the original integral value naturally decays to 0 over time, and finally the crawling torque gradually returns to 0 from the current value, realizing a seamless transition from the crawling mode to normal driving (e.g., when the driver continues to accelerate, the crawling torque gradually exits, without a sense of power interruption).

[0104] The three modes adopted by the embodiments of the present application for different exit scenarios realize the organic unification of safety, smoothness and scenario adaptability through precise matching of trigger conditions and exit logic. In emergency scenarios such as faults and gear shifting, the first mode directly clears the crawling torque and the integral term to achieve rapid exit, eliminating safety risks. For the brake pedal down scenario, the second mode sets the target crawling speed to 0 to guide the torque to decay smoothly, avoiding the conflict between the crawling torque and the braking force that causes impact. For the natural transition scenario of vehicle speed exceeding the limit, the third mode keeps the target speed unchanged to make the crawling torque naturally return to 0 with the integral term, realizing a seamless connection from crawling to normal driving. The three modes are adaptively graded from emergency to normal scenarios, ensuring safety priority and eliminating the jerkiness of mode switching through torque gradual change, making the exit logic of the crawling mode more intelligent and more in line with actual driving needs.

[0105] On the basis of the above-mentioned embodiments, the embodiments of the present application further provide a vehicle crawling control device, which comprises:

[0106] An acquisition module is configured to acquire running data of a vehicle.

[0107] A determination module is configured to determine a crawling torque according to an actual driving speed of the vehicle and a target crawling speed of the vehicle when the running data meets a preset condition for entering a crawling mode.

[0108] A control module is configured to superimpose the crawling torque and a drive pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target crawling speed.

[0109] In a possible implementation, the determination module is specifically configured to perform proportional calculation and integral calculation on the target crawling speed and the actual driving speed by using a speed loop PI controller to obtain the crawling torque.

[0110] In a possible implementation, the determining module is specifically configured to determine a speed difference value obtained by subtracting the actual driving speed from the target crawling speed; in a case where the brake pedal of the vehicle is stepped on, a first torque is obtained by integrating the speed difference value and a first integral coefficient; in a case where the brake pedal of the vehicle is not stepped on, a first torque is obtained by integrating the speed difference value and a second integral coefficient; a second torque is obtained according to the speed difference value and a proportional coefficient; and the first torque and the second torque are added to obtain the crawling torque.

[0111] In a possible implementation, the determining module is further configured to, in the process of integrating according to the speed difference value, stop the integral accumulation when the integral accumulation value is greater than or equal to a maximum limit value of the crawling torque.

[0112] In a possible implementation, the control module is further configured to, in a case where the running data satisfies a preset condition for exiting the crawling mode, exit the crawling mode according to a first mode, a second mode or a third mode according to the running data; wherein a speed of exiting the crawling mode in the first mode is greater than a speed of exiting the crawling mode in the second mode, and the speed of exiting the crawling mode in the second mode is greater than a speed of exiting the crawling mode in the third mode.

[0113] In a possible implementation, the preset condition for exiting the crawling mode includes that the vehicle exits a preparation mode, a gear of the vehicle is in a parking gear or a neutral gear, an automatic parking function of the vehicle is activated, a vehicle speed of the vehicle is greater than a crawling vehicle speed threshold, the brake pedal of the vehicle is stepped on, or the vehicle has a fault affecting normal driving of the vehicle.

[0114] In a possible implementation, the control module is specifically configured to, in a case where the vehicle exits the preparation mode, the gear of the vehicle is in the parking gear or the neutral gear, the automatic parking function of the vehicle is activated, or the vehicle has the fault affecting the normal driving of the vehicle, exit the crawling mode in the first mode; in a case where the brake pedal of the vehicle is stepped on, exit the crawling mode in the second mode; and in a case where the vehicle speed of the vehicle is greater than the crawling vehicle speed threshold, exit the crawling mode in the third mode.

[0115] In a possible implementation, the control module exits the crawling mode in the first mode, and the method specifically includes:

[0116] The crawling torque output by a speed loop PI controller is set to 0, and a first torque obtained by accumulating an integral term in the speed loop PI controller is set to 0.

[0117] The control module exits the crawling mode in the second mode, specifically including:

[0118] The target crawling speed input into the speed loop PI controller is set to 0;

[0119] The control module exits the crawling mode in the third mode, specifically including:

[0120] The target crawling speed input into the speed loop PI controller is kept unchanged.

[0121] In a possible implementation, the embodiments of the present application further provide a control device.

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

[0123] The memory can store computer instructions, when the computer instructions stored in the memory are executed by the processor, the processor can be used for the vehicle crawling control method. The memory can also store data, for example, the information of the preset range, the preset threshold, etc. involved in the above embodiments.

[0124] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The 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 processes or functions according to the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), or semiconductor media (such as solid state disk (Solid State Disk, SSD)) and the like.

[0125] The embodiments of the present application also provide a readable storage medium for storing the method provided by the above embodiments. For example, random access memory (Random Access Memory, RAM), flash memory, read only memory (Read Only Memory, ROM), EPROM memory, non-volatile read only memory (Electronic Programmable ROM, EPROM), register, hard disk, removable disk or any other form of storage medium in the art.

[0126] The "first" and "second" in the names mentioned in the embodiments of the present application (if any) are only used for name identification, and do not represent the first and second in order.

[0127] It should be noted that the embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the method disclosed in the embodiments, since it corresponds to the product embodiment disclosed in the embodiments, the description is relatively simple, and the relevant part can be referred to the description of the product embodiment.

[0128] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended 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 vehicle crawl control method, characterized by, The method comprises: acquiring running data of a vehicle; in a case where the running data meets preset conditions for entering a crawling mode, determining a crawling torque according to an actual driving speed of the vehicle and a target crawling speed of the vehicle; superimposing the crawling torque and a driving pedal torque of the vehicle to control the actual driving speed of the vehicle to approach the target crawling speed.

2. The method of claim 1, wherein, The determination of the crawling torque according to the actual driving speed of the vehicle and the target crawling speed of the vehicle comprises: performing proportional calculation and integral calculation on the target crawling speed and the actual driving speed by using a speed loop PI controller to obtain the crawling torque.

3. The method of claim 2, wherein, The proportional calculation and integral calculation on the target crawling speed and the actual driving speed by using the speed loop PI controller to obtain the crawling torque comprises: determining a speed difference value obtained by subtracting the actual driving speed from the target crawling speed; in a case where a brake pedal of the vehicle is depressed, performing integral calculation on the speed difference value and a first integral coefficient to obtain a first torque; in a case where the brake pedal of the vehicle is not depressed, performing integral calculation on the speed difference value and a second integral coefficient to obtain a first torque; obtaining a second torque according to the speed difference value and a proportional coefficient; adding the first torque and the second torque to obtain the crawling torque.

4. The method of claim 3, wherein, The method further comprises, in the process of performing integral calculation according to the speed difference value, stopping integral accumulation when an integral accumulation value is greater than or equal to a maximum limit value of the crawling torque.

5. The method of claim 1, wherein, The method further comprises: in a case where the running data meets preset conditions for exiting the crawling mode, adopting a first mode, a second mode or a third mode to exit the crawling mode according to the running data; wherein a speed of adopting the first mode to exit the crawling mode is greater than a speed of adopting the second mode to exit the crawling mode, and the speed of adopting the second mode to exit the crawling mode is greater than a speed of adopting the third mode to exit the crawling mode.

6. The method of claim 5, wherein, The preset conditions for exiting the crawling mode comprise: the vehicle exits a preparation mode; a gear position of the vehicle is in a parking gear or a neutral gear; an automatic parking function of the vehicle is activated; a vehicle speed of the vehicle is greater than a crawling vehicle speed threshold; the brake pedal of the vehicle is depressed; the vehicle has a fault affecting normal driving of the vehicle.

7. The method of claim 5, wherein, The adoption of the first mode, the second mode or the third mode to exit the crawling mode according to the running data in the case where the running data meets the preset conditions for exiting the crawling mode comprises: in a case where the vehicle exits the preparation mode, the gear position of the vehicle is in the parking gear or the neutral gear, the automatic parking function of the vehicle is activated or the vehicle has the fault affecting the normal driving of the vehicle, the first mode is adopted to exit the crawling mode; in a case where the brake pedal of the vehicle is depressed, the second mode is adopted to exit the crawling mode; in a case where the vehicle speed of the vehicle is greater than the crawling vehicle speed threshold, the third mode is adopted to exit the crawling mode.

8. The method according to any one of claims 5 to 7, characterized in that, The adoption of the first mode to exit the crawling mode comprises: set the output of the speed loop PI controller to 0 and set the first torque accumulated by the integral term in the speed loop PI controller to 0; adopting the second mode to exit the inching mode, comprising: setting the target inching speed input to the speed loop PI controller to 0; adopting the third mode to exit the inching mode, comprising: keeping the target inching speed input to the speed loop PI controller unchanged.

9. A control device characterized by comprising: a processor and a memory, the memory being used to store programs, instructions or codes, the processor being used to execute the programs, instructions or codes in the memory to complete the automobile inching control method as claimed in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, a computer program is stored, the computer program is loaded by a processor to execute the automobile inching control method as claimed in any one of claims 1-8.

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