Vehicle off-road crawl control system and vehicle

Abstract

This application discloses a vehicle off-road crawl control system and a vehicle. The system includes: a human-machine interface module configured to receive a speed adjustment command or an off-road mode selection command triggered by the driver; a torque control module configured to receive and calculate machine drive torque or machine braking torque based on the speed adjustment command or the off-road mode selection command, and by receiving vehicle operating data; and a torque arbitration module configured to receive the machine drive torque or the machine braking torque, and to receive the manual drive torque or manual braking torque generated by the driver's operation, and to perform torque arbitration in conjunction with the vehicle operating data, outputting a target drive torque or target braking torque to the vehicle actuator to control the vehicle actuator to drive or brake the vehicle. The technical solution provided by this application can improve the accuracy of vehicle off-road crawl control.

Description

Technical Field

[0001] This application belongs to the field of vehicle torque control technology, and in particular relates to a vehicle off-road crawl control system and vehicle. Background Technology

[0002] As off-road performance continues to improve, the driving scenarios for off-road vehicles are gradually expanding to complex road conditions such as steep slopes, gravel, mud, and rocky roads. Off-road crawl control has become a key feature to improve the vehicle's ability to pass through complex road conditions. It can help the vehicle achieve stable driving at low speeds and effectively reduce the driver's workload.

[0003] However, existing off-road crawl control technologies mostly rely on single signals such as vehicle speed and slope for control, lacking precise perception of terrain adhesion conditions and wheel force states. The response speed and adaptability of torque control are insufficient, which can easily lead to sudden changes in driving force, wheel slippage, or getting stuck. At the same time, the switching between manual operation by the driver and automatic control by the system is not smooth enough, making it difficult to achieve fine and adaptive torque adjustment in complex off-road scenarios.

[0004] Therefore, improving the accuracy of vehicle off-road crawl control has become an urgent technical problem to be solved. Summary of the Invention

[0005] The embodiments of this application provide a vehicle off-road crawl control system and a vehicle, which can at least to some extent improve the accuracy of vehicle off-road crawl control.

[0006] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0007] According to a first aspect of the embodiments of this application, a vehicle off-road crawl control system is provided. The system includes: a human-machine interface module configured to receive a vehicle speed adjustment command or an off-road mode selection command triggered by a driver, the vehicle speed adjustment command including an acceleration command and a deceleration command; a torque control module communicatively connected to the human-machine interface module, configured to receive the vehicle speed adjustment command or the off-road mode selection command, and receive vehicle operating data, and calculate machine drive torque or machine braking torque based on the vehicle speed adjustment command or the off-road mode selection command and the vehicle operating data; and a torque arbitration module communicatively connected to the torque control module and a vehicle actuator, configured to receive the machine drive torque or the machine braking torque, and receive the manual drive torque or manual braking torque generated by the driver's operation, and perform torque arbitration in conjunction with the vehicle operating data, outputting a target drive torque or a target braking torque to the vehicle actuator to control the vehicle actuator to drive or brake the vehicle.

[0008] In some embodiments of this application, based on the foregoing scheme, the torque control module includes a vehicle speed adjustment module, an acceleration loop module, a control mode decision module, and a torque loop module that are interconnected; the vehicle speed adjustment module is configured to: adjust the target vehicle speed according to the vehicle speed adjustment command or the off-road mode selection command; the acceleration loop module is configured to: calculate the desired acceleration based on the actual vehicle speed and the target vehicle speed, and determine the vehicle control mode based on the desired acceleration; the control mode decision module is configured to: decide the control mode of the vehicle off-road crawl control system based on the vehicle control mode and the vehicle operating data; the torque loop module is configured to: calculate the machine drive torque or the machine braking torque based on the control mode and the desired acceleration.

[0009] In some embodiments of this application, based on the aforementioned scheme, the vehicle speed adjustment module has multiple built-in set vehicle speeds and initial vehicle speeds set for different off-road modes. The vehicle speed adjustment module is configured to: perform upward rounding on the actual vehicle speed according to the acceleration command to match the corresponding set vehicle speed as the vehicle's target speed; or, perform downward rounding on the actual vehicle speed according to the deceleration command to match the corresponding set vehicle speed as the vehicle's target speed; or, match the corresponding initial vehicle speed as the vehicle's target speed according to the off-road mode specified by the off-road mode selection command.

[0010] In some embodiments of this application, based on the aforementioned scheme, the acceleration loop module is configured to: calculate the desired acceleration of the vehicle at the actual vehicle speed based on the difference between the actual vehicle speed and the target vehicle speed; determine the idle speed trigger boundary and the braking trigger boundary based on a pre-calibrated acceleration reference curve, wherein the acceleration reference curve is a quadratic function curve used to characterize the correspondence between vehicle speed and acceleration during coasting in gear, and the braking trigger boundary is smaller than the idle speed trigger boundary, and the idle speed trigger boundary is less than 0; and select one of the drive control mode, idle speed control mode, and braking control mode as the vehicle control mode based on the relationship between the desired acceleration and the idle speed trigger boundary and the braking trigger boundary.

[0011] In some embodiments of this application, based on the foregoing scheme, the acceleration loop module is further configured to: when the vehicle is running in drive control mode, if the desired acceleration is less than the idle speed trigger boundary, select idle speed control mode as vehicle control mode; when the vehicle is running in idle speed control mode, if the desired acceleration is less than the braking trigger boundary, select braking control mode as vehicle control mode; when the vehicle is running in braking control mode, if the desired acceleration is greater than 0 and the duration is greater than a set duration, select drive control mode as vehicle control mode.

[0012] In some embodiments of this application, based on the foregoing scheme, the control mode includes a hydraulic braking mode corresponding to the braking control mode, an idle speed mode corresponding to the idle speed control mode, and a drive mode corresponding to the drive control mode; the control mode decision module is configured to: output an escape flag signal when it is determined that the vehicle triggers an escape condition set for potholes or bumps during downhill driving, based on vehicle operating data; the escape condition includes the vehicle being blocked on an undulating downhill road, the vehicle having excessive driving resistance on a small downhill slope with high resistance, and the driver instructing the vehicle to accelerate on a small downhill slope but the acceleration is insufficient; respond to the escape flag signal to force the vehicle to exit the hydraulic braking mode or idle speed mode and switch to the drive mode; transmit the control mode signal to the torque loop module so that the torque loop module adjusts the torque calculation logic according to the control mode signal.

[0013] In some embodiments of this application, based on the foregoing scheme, the torque loop module is configured to: calculate the machine drive torque or the machine braking torque through a fusion of feedforward control and feedback control, wherein the feedforward control includes braking feedforward control and drive feedforward control, the braking feedforward control calculates the machine braking torque according to the vehicle longitudinal dynamics equation, the drive feedforward control calculates the machine drive torque according to a set vehicle speed-gradient-torque correspondence table, and the feedback control uses an incremental PID controller, which calculates a torque correction value based on the error between the desired acceleration and the actual vehicle acceleration; when the override module in the torque arbitration module is in a partial override state or a full override state, the torque loop module disables the incremental PID controller and only retains the feedforward control; after the driver's override operation ends, the torque loop module is set with dual limit rules for the vehicle's deceleration process, including an acceleration upper limit and a torque upper limit.

[0014] In some embodiments of this application, based on the foregoing scheme, the torque arbitration module includes a override module, which is configured to: determine the control execution subject based on the manual drive torque or the manual braking torque, and the machine drive torque or the machine braking torque; when the vehicle is in a first unidirectional operating condition or a second unidirectional operating condition, select the torque with the larger torque value as the basis for control execution; wherein, the first unidirectional operating condition is the condition in which the machine drive torque and the manual drive torque coexist, and the second unidirectional operating condition is the condition in which the machine braking torque and the manual braking torque coexist; when the vehicle is in a first reverse operating condition or a second reverse operating condition, use the torque generated by the driver's operation as the basis for control execution; wherein, the first reverse operating condition is the condition in which the machine drive torque and the manual braking torque coexist, and the second reverse operating condition is the condition in which the machine braking torque and the manual drive torque coexist.

[0015] In some embodiments of this application, based on the foregoing scheme, the operating states of the override module include: a non-responsive state, where the torque value generated by the driver operating the accelerator pedal or brake pedal is less than a first set threshold, and the vehicle off-road crawl control system maintains autonomous control; a partial override state, where the torque value generated by the driver operating the accelerator pedal or brake pedal is between the first and second set thresholds, and only the target vehicle speed is adjusted while the torque is autonomously controlled by the vehicle off-road crawl control system; and a full override state, where the torque value generated by the driver operating the accelerator pedal or brake pedal is greater than the second set threshold, and the driver completely takes over vehicle control.

[0016] According to a second aspect of the embodiments of this application, a vehicle is provided, the vehicle being equipped with a vehicle off-road crawl control system as described in any of the embodiments of the first aspect above.

[0017] Based on the technical solution proposed in this application, a complete control architecture is constructed by setting up a human-machine interaction module, a torque control module, and a torque arbitration module that communicate with each other, from command reception and torque calculation to torque arbitration execution. The system can simultaneously receive driver operation commands and real-time vehicle operation data, realizing the combination of manual operation and automatic system control. It can accurately calculate and arbitrate torque output according to the actual driving status of the vehicle, avoiding the problem of insufficient control accuracy caused by the single reliance on vehicle speed and slope signals in the prior art. At the same time, the torque arbitration module realizes the smooth connection between manual torque and machine torque, which can effectively solve the problem of uneven switching between driver manual operation and automatic system control, making the torque output of the system more in line with the actual needs of complex off-road scenarios, thereby improving the overall accuracy of vehicle off-road crawl control. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0019] Figure 1 An architecture diagram of the vehicle off-road crawl control system in an embodiment of this application is shown; Figure 2 An architectural diagram of the torque control module in an embodiment of this application is shown; Figure 3 A schematic diagram of the vehicle control mode switching strategy in an embodiment of this application is shown; Figure 4 A schematic diagram showing the working state distribution of the overdrive module in an embodiment of this application is shown; Figure 5 A schematic diagram of the vehicle structure in an embodiment of this application is shown. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0022] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices. It should also be noted that, for the sake of simplicity, certain components in the drawings that do not affect the interpretation of the technical solution of this application have been appropriately omitted.

[0023] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined. Therefore, the actual execution order may change depending on the actual situation.

[0024] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0025] This application proposes a vehicle off-road crawl control scheme, which aims to improve the accuracy of vehicle off-road crawl control, so as to solve the problems of insufficient accuracy and uneven switching of existing off-road crawl control technology, realize the fine and adaptive adjustment of torque in complex off-road scenarios, and improve the stability and passability of vehicle off-road driving.

[0026] Next, this application will elaborate on the proposed vehicle off-road crawl control system.

[0027] Reference Figure 1 The diagram shows the architecture of the vehicle off-road crawl control system in an embodiment of this application.

[0028] like Figure 1As shown, the system may include a human-machine interaction module, a torque control module, and a torque arbitration module. These modules communicate and cooperate with each other to achieve precise torque control during the vehicle's off-road crawling process. The following provides a detailed explanation of the specific implementation methods of each module and the system.

[0029] In this application, the human-computer interaction module can be configured to receive a vehicle speed adjustment command or an off-road mode selection command triggered by the driver, wherein the vehicle speed adjustment command includes an acceleration command and a deceleration command.

[0030] Specifically, the human-machine interface module acts as a bridge between the driver and the system, and can receive the driver's operation commands. For example, the driver can trigger the above commands through the physical buttons of the module or the touch buttons of the vehicle terminal (adjusted via the "set+" and "set-" buttons). For instance, when the vehicle is traveling on a rocky road, the driver can select the rock off-road mode through the touch buttons, or trigger the speed-up command through the speed-up button while driving at low speed.

[0031] In this application, the human-machine interaction module may further include an off-road switch button for the driver to select whether to turn the crawl function on or off.

[0032] In addition, the human-machine interaction module may also include an instrument display device for displaying the working status of the vehicle's off-road crawl control system, such as the activation status, availability status, target vehicle speed, and prompt information of the crawl function.

[0033] In this application, the torque control module is communicatively connected to the human-machine interaction module, and can be configured to: receive the vehicle speed adjustment command or the off-road mode selection command, and receive vehicle operating data, and calculate the machine drive torque or machine braking torque according to the vehicle speed adjustment command or the off-road mode selection command and the vehicle operating data.

[0034] Specifically, the vehicle operation data can refer to various data collected in real time by different vehicle sensors that reflect the vehicle's driving status and hardware status, such as vehicle speed data collected by wheel speed sensors, slope data collected by gradient sensors, and pedal operation data collected by pedal sensors. The torque control module can calculate the machine's drive torque or braking torque based on the above data and driver commands using a preset algorithm.

[0035] In this application, the torque arbitration module is communicatively connected to the torque control module and the vehicle actuator, respectively. It can be configured to: receive the machine drive torque or the machine braking torque, and receive the manual drive torque or manual braking torque generated by the driver's operation, and perform torque arbitration in combination with the vehicle operation data, and output the target drive torque or target braking torque to the vehicle actuator to control the vehicle actuator to drive or brake the vehicle.

[0036] In this application, for example, when the torque control module calculates a machine drive torque of 100 Nm, and the driver's manual drive torque generated by pressing the accelerator is 120 Nm, the torque arbitration module, after arbitration, outputs the 120 Nm manual drive torque as the target drive torque to the vehicle drive motor, and the drive motor performs the power output operation.

[0037] Based on the above scheme, by setting up a human-machine interaction module, a torque control module, and a torque arbitration module that communicate with each other, a complete control architecture is constructed from command reception, torque calculation to torque arbitration execution. The system can simultaneously receive driver operation commands and real-time vehicle operation data, realizing the combination of manual operation and automatic system control. It can accurately calculate and arbitrate torque output according to the actual driving status of the vehicle, avoiding the problem of insufficient control accuracy caused by the single reliance on vehicle speed and slope signals in existing technologies. At the same time, the torque arbitration module realizes the smooth connection between manual torque and machine torque, which can effectively solve the problem of uneven switching between driver manual operation and automatic system control, making the system's torque output more in line with the actual needs of complex off-road scenarios, thereby improving the overall accuracy of vehicle off-road crawl control.

[0038] Reference Figure 2 The diagram shows the architecture of the torque control module in an embodiment of this application.

[0039] like Figure 2 As shown in this application, the torque control module may include a vehicle speed adjustment module, an acceleration loop module, a control mode decision module, and a torque loop module that are interconnected. Each sub-module works together to complete the entire process from target vehicle speed adjustment to machine torque calculation, and is the core unit for achieving accurate torque calculation.

[0040] In this application, the vehicle speed adjustment module can be configured to adjust the target vehicle speed according to the vehicle speed adjustment command or the off-road mode selection command.

[0041] The speed adjustment module is the foundation of the system's speed control. It directly matches and sets the target speed according to the driver's instructions. For example, when the driver triggers an acceleration command, the speed adjustment module matches the target speed upwards based on the vehicle's current actual speed. When the driver selects the sand off-road mode, the speed adjustment module directly retrieves the preset initial speed corresponding to the sand mode as the target speed.

[0042] In this application, the acceleration loop module can be configured to: calculate the desired acceleration based on the actual vehicle speed and the target vehicle speed, and determine the vehicle control mode based on the desired acceleration.

[0043] The desired acceleration is the acceleration required for the vehicle to reach the target speed from the actual speed. The acceleration loop module can determine the control mode required by the vehicle by calculating this parameter. For example, when the actual speed is lower than the target speed, the calculated desired acceleration is positive. At this time, it is determined that the vehicle needs a drive control mode to increase the speed to the target speed.

[0044] In this application, the control mode decision module can be configured to: determine the control mode of the vehicle off-road crawl control system based on the vehicle control method and the vehicle operation data.

[0045] Based on the vehicle control mode determined by the acceleration loop module, the control mode decision module makes further mode decisions by combining real-time vehicle operation data. This allows the system's control mode to be more adapted to the actual driving conditions of the vehicle. For example, if the acceleration loop module determines that the braking control mode is selected, but the vehicle is stuck in a downhill ditch, the control mode decision module will adjust the system control mode to the driving mode to help the vehicle get out of trouble.

[0046] In this application, the torque loop module can be configured to calculate the machine drive torque or the machine braking torque based on the control mode and the desired acceleration.

[0047] The torque loop module is the final calculation unit of the torque control module. Based on the control mode determined by the control mode decision module and the expected acceleration calculated by the acceleration loop module, it completes the accurate calculation of machine drive torque or machine braking torque through a preset control algorithm. For example, when the system control mode is drive mode and the expected acceleration is 0.5 m / s², the torque loop module calculates the corresponding machine drive torque according to the above parameters. When the system control mode is braking mode and the expected acceleration is -0.3 m / s², the torque loop module calculates the corresponding machine braking torque.

[0048] In practical applications, the workflow of each sub-module forms a complete logical link. For example, after the driver triggers the sand mode selection command through the human-machine interaction module, the vehicle speed adjustment module first retrieves the initial vehicle speed of 20 km / h corresponding to the sand mode as the target vehicle speed. The acceleration loop module collects the current actual vehicle speed of 15 km / h and calculates the expected acceleration from 15 km / h to 20 km / h. Based on this expected acceleration, the vehicle is determined to be in drive control mode. The control mode decision module combines the current slope, road resistance and other operating data of the vehicle to confirm that the system control mode is drive mode. Finally, the torque loop module calculates the corresponding machine drive torque based on the drive mode and the expected acceleration, completing the pre-process of the entire torque calculation.

[0049] Based on the above scheme, by dividing the torque control module into four interconnected sub-modules—a vehicle speed adjustment module, an acceleration loop module, a control mode decision module, and a torque loop module—a refined division of labor can be achieved in the torque calculation process. Each sub-module completes the functions of target speed adjustment, control mode judgment, control mode decision, and final torque calculation, ensuring that each calculation step is aligned with the actual driving state of the vehicle. This avoids calculation errors caused by the single torque calculation logic in existing technologies. At the same time, the collaborative work of each sub-module forms a complete calculation link, making the machine torque calculation more logical and accurate. This provides accurate machine torque data for subsequent torque arbitration, thereby improving the torque control accuracy of the entire system. Furthermore, the refined module division of labor allows the system to flexibly adjust the calculation logic according to the needs of different off-road scenarios, enhancing the system's adaptability to complex off-road conditions.

[0050] Next, this application will elaborate on each sub-module of the torque control module.

[0051] In this application, the vehicle speed adjustment module may have multiple set vehicle speeds and initial vehicle speeds set for different off-road modes.

[0052] The vehicle speed adjustment module can be configured to: round up the actual vehicle speed according to the acceleration command to match the corresponding set speed as the vehicle's target speed; or, round down the actual vehicle speed according to the deceleration command to match the corresponding set speed as the vehicle's target speed; or, match the corresponding initial speed as the vehicle's target speed according to the off-road mode specified by the off-road mode selection command.

[0053] In this application, the vehicle speed adjustment module can adjust the target vehicle speed through three different adjustment methods, each adapting to different operating commands of the driver, ensuring that the target vehicle speed setting matches the driver's operating intentions and the needs of off-road scenarios.

[0054] Specifically, the first adjustment method is to round up the actual vehicle speed according to the speed-up command to match the corresponding set speed as the target speed of the vehicle. For example, the speed adjustment module has built-in set speeds including fixed values ​​such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 21, 23, 25, and 27 kilometers per hour. When the actual vehicle speed is 3.2 kilometers per hour, and the driver triggers the speed-up command, the module rounds up 3.2 kilometers per hour to match the set speed of 4 kilometers per hour as the target speed.

[0055] The second adjustment method is to round down the actual vehicle speed according to the speed reduction command, and match the corresponding set speed as the target speed of the vehicle. For example, if the actual vehicle speed is 4.8 kilometers per hour, when the driver triggers the speed reduction command, the module rounds down 4.8 kilometers per hour and matches the set speed of 4 kilometers per hour as the target speed.

[0056] The third adjustment method is to match the initial vehicle speed corresponding to the off-road mode specified by the off-road mode selection command as the target vehicle speed. For example, the vehicle speed adjustment module presets initial speeds of 8, 13, 4, 3 and 3 kilometers per hour for snow mode, sand mode, mud mode, rock mode and wading mode respectively. When the driver selects rock mode, the module directly sets the initial speed of 3 kilometers per hour as the target vehicle speed, without requiring the driver to manually adjust the speed.

[0057] In actual off-road scenarios, the three adjustment methods of the vehicle speed adjustment module can be flexibly switched. For example, when the driver drives the vehicle to a snowy road, he first selects the snow off-road mode through the human-machine interaction module. The vehicle speed adjustment module directly matches an initial speed of 8 kilometers per hour as the target speed. During the vehicle's journey, if the driver feels that the current speed is too fast, he triggers a deceleration command. At this time, the actual vehicle speed is 7.5 kilometers per hour. The vehicle speed adjustment module performs a rounding down operation and matches the set speed of 7 kilometers per hour as the new target speed, thus completing the target speed adjustment. If the driver subsequently feels that the speed is too slow and triggers an acceleration command, the module performs a rounding up operation on the actual speed of 7.5 kilometers per hour and matches the set speed of 8 kilometers per hour as the target speed.

[0058] Based on the above solution, by embedding a fixed set speed and initial speeds corresponding to different off-road modes in the speed adjustment module, and combining three target speed adjustment methods—rounding up, rounding down, and off-road mode matching—the target speed setting can be made more standardized and adaptable, avoiding speed fluctuations caused by irregular speed adjustments. Furthermore, by presetting exclusive initial speeds for different off-road modes, the target speed can directly match the driving needs of different off-road conditions. For example, a low initial speed is preset for rocky roads to ensure precise vehicle passage, while a moderate initial speed is preset for sandy roads to prevent deep wheel slippage. In addition, the rounding method allows the speed adjustment to better match the driver's operating intentions, making the target speed adjustment more precise and efficient. This provides an accurate speed reference for subsequent acceleration and torque calculations, thereby improving the overall system control accuracy.

[0059] In this application, the acceleration loop module can also be configured to: calculate the desired acceleration of the vehicle at the actual vehicle speed based on the difference between the actual vehicle speed and the target vehicle speed; determine the idle speed trigger boundary and the braking trigger boundary based on a pre-calibrated acceleration reference curve, wherein the acceleration reference curve is a quadratic function curve used to characterize the correspondence between vehicle speed and acceleration during coasting in gear, and the braking trigger boundary is smaller than the idle speed trigger boundary, and the idle speed trigger boundary is less than 0; and select one of the drive control mode, idle speed control mode, and braking control mode as the vehicle control mode based on the relationship between the desired acceleration and the idle speed trigger boundary and the braking trigger boundary.

[0060] The acceleration loop module, as the vehicle control mode determination unit, can accurately calculate the desired acceleration and combine it with the preset acceleration boundary to determine the three control modes of vehicle driving, idling, and braking, providing an accurate basis for subsequent control mode decisions.

[0061] Specifically, the acceleration loop module is first configured to calculate the vehicle's expected acceleration at the actual vehicle speed based on the difference between the actual vehicle speed and the target vehicle speed. This calculation of expected acceleration is fundamental to the acceleration loop module's operation. This parameter directly reflects the acceleration requirement for the vehicle to reach the target speed from its current actual speed. For example, if the actual vehicle speed is 5 km / h and the target speed is 8 km / h, the difference is 3 km / h. Based on this difference and a preset algorithm, the acceleration loop module calculates the expected acceleration at the actual speed of 5 km / h as 0.4 m / s². If the actual speed is 8 km / h and the target speed is 5 km / h, the difference is -3 km / h, and the calculated expected acceleration is -0.3 m / s².

[0062] In this application, the acceleration reference curve is not obtained by theoretical calculation, but by calibration through actual vehicle test. Specifically, the test vehicle is subjected to a coasting test in gear, and the actual acceleration data of the vehicle at different speeds is collected. The collected data is fitted to obtain the acceleration reference curve in the form of a quadratic function, as shown in formula (1): (1) Where A and B are acceleration coefficients, and C is the acceleration constant.

[0063] In this application, the acceleration reference curve accurately reflects the vehicle's natural coasting acceleration characteristics, and the idle speed trigger boundary and braking trigger boundary determined based on this curve better match the vehicle's actual driving characteristics. Both the idle speed trigger boundary and the braking trigger boundary are negative acceleration values, with the braking trigger boundary having a larger absolute value. For example, the idle speed trigger boundary is -0.2 m / s², and the braking trigger boundary is -0.5 m / s². This numerical setting allows the system to accurately distinguish between idle speed and braking control modes based on different acceleration requirements.

[0064] Reference Figure 3 The diagram illustrates a vehicle control mode switching strategy in an embodiment of this application.

[0065] like Figure 3 As shown, in order to make the switching between drive and braking smoother and avoid large control overshoot and lag, a certain transition zone (i.e., the vacuum zone between the idle speed trigger boundary a1 and the braking trigger boundary a2) is set near the acceleration reference curve to solve the problem of large acceleration following error in this region.

[0066] In this application, the selection of the three vehicle control methods—drive control, idle speed control, and braking control—follows a clear numerical comparison logic. For example, ... Figure 3 When the desired acceleration is greater than the idle trigger boundary, it indicates that the vehicle's current acceleration requirement is positive. In this case, the vehicle does not need to idle or brake, and the drive control mode can be selected. When the desired acceleration is between the idle trigger boundary and the brake trigger boundary, it indicates that the vehicle needs a small amount of acceleration. In this case, the idle control mode can be selected to allow the vehicle to coast naturally. When the desired acceleration is less than the brake trigger boundary, it indicates that the vehicle needs a larger specified acceleration (the acceleration value is negative). In this case, the brake control mode should be selected to apply active braking force to the vehicle.

[0067] Based on the above scheme, the expected acceleration is calculated by the difference between the actual vehicle speed and the target vehicle speed. This allows the acceleration determination to better match the vehicle's speed adjustment needs. Simultaneously, the idle speed trigger boundary and braking trigger boundary are determined based on the acceleration reference curve calibrated from real vehicle tests. This ensures that the boundary values ​​more closely match the vehicle's actual driving characteristics, avoiding discrepancies between theoretically calculated boundary values ​​and actual vehicle driving. Furthermore, the vehicle control mode is determined by the relationship between the expected acceleration and the two boundary values. This provides a clear and precise numerical basis for the control mode determination, effectively improving the accuracy of vehicle control mode judgment. This provides accurate preliminary judgment results for subsequent control mode decisions and torque calculations, ultimately allowing the system's torque output to better match the vehicle's actual acceleration requirements and improving the overall control accuracy of the system.

[0068] In this application, the acceleration loop module can also be configured to: when the vehicle is running in drive control mode, if the desired acceleration is less than the idle speed trigger boundary, select idle speed control mode as the vehicle control mode; when the vehicle is running in idle speed control mode, if the desired acceleration is less than the braking trigger boundary, select braking control mode as the vehicle control mode; when the vehicle is running in braking control mode, if the desired acceleration is greater than 0 and the duration is greater than a set duration, select drive control mode as the vehicle control mode.

[0069] The acceleration loop module also sets clear rules for switching vehicle control modes. Different switching trigger conditions are set for different current control modes of the vehicle, so that the switching of control modes is smoother and more in line with the actual needs of off-road scenarios, avoiding the problem of vehicle driving jerking caused by frequent switching.

[0070] Specifically, the acceleration loop module is configured to select idle control as the vehicle control mode when the desired acceleration is less than the idle trigger boundary during vehicle operation in drive control mode. For example, if the vehicle is currently driving in drive control mode and the idle trigger boundary is -0.2 m / s², as the actual vehicle speed gradually approaches the target speed, the desired acceleration calculated by the acceleration loop module becomes -0.25 m / s², which is less than the idle trigger boundary. At this time, the acceleration loop module switches the vehicle control mode from drive control mode to idle control mode, allowing the vehicle to transition from active drive to natural coasting, achieving a smooth speed transition.

[0071] When the vehicle is operating in idle control mode, if the desired acceleration is less than the braking trigger boundary, braking control mode is selected as the vehicle control mode. For example, if the vehicle is currently coasting naturally in idle control mode with a braking trigger boundary of -0.5 m / s², and the vehicle travels downhill and the actual speed exceeds the target speed, the desired acceleration calculated by the acceleration loop module becomes -0.6 m / s², which is less than the braking trigger boundary. At this time, the acceleration loop module switches the vehicle control mode from idle control mode to braking control mode, applying active braking force to the vehicle to reduce the speed to the target value.

[0072] When the vehicle is operating in braking control mode, if the desired acceleration is greater than 0 and the duration is longer than a set duration, the drive control mode is selected as the vehicle control mode. This rule sets dual trigger conditions for switching from braking control mode to drive control mode: both the desired acceleration must be positive and the state must last for a certain duration, for example, a set duration of 0.5 seconds, a braking trigger boundary of -0.5 m / s², and the vehicle is currently traveling in braking control mode. When the desired acceleration calculated by the acceleration loop module becomes 0.2 m / s² and this value remains unchanged for 0.5 seconds, the acceleration loop module can switch the vehicle control mode from braking control mode to drive control mode.

[0073] Based on the above scheme, by setting clear and realistic trigger conditions for switching between different control modes, the switching of vehicle control modes can be made more logical and stable. In particular, the design of the hysteresis strategy when releasing the brake and the dual trigger conditions set for switching from braking control mode to driving control mode can effectively avoid the problem of frequent switching of control modes caused by short-term fluctuations in vehicle speed due to bumpy off-road conditions. This reduces the frequent alternation of the vehicle's driving, idling, and braking states, making the vehicle's driving state more stable. At the same time, the smooth switching of control modes can also make the subsequent torque output more stable, avoiding sudden changes in driving force or braking force, improving the smoothness and stability of the vehicle when driving in complex off-road conditions, and thus improving the accuracy of the system's crawl control.

[0074] In this application, the acceleration loop module also incorporates additional control mode restriction states in the control areas corresponding to the drive control mode, idle speed control mode, and braking control mode, based on the results of real vehicle tests. Specifically, dedicated control adjustment rules are set up for common off-road driving conditions such as S-curves, low-speed downhill potholes, and S-curve gradient lag. Specifically, in S-curve conditions, when the vehicle enters active braking control, the acceleration loop module switches the vehicle's braking control to a pre-set curve braking control state to meet the braking requirements of curve driving. In low-speed downhill pothole conditions, when the vehicle speed drops to zero and the braking torque decreases to zero but the vehicle still does not show any tendency to move, the acceleration loop module controls the vehicle to exit active braking control and directly switches to drive control mode to provide driving force to the vehicle to escape the pothole obstacle. In S-curve gradient lag conditions, the acceleration loop module promptly controls the vehicle to exit drive control mode and switch to active braking control mode to avoid the speed control risks caused by gradient signal lag and meet the driving control requirements of curves.

[0075] In this application, the control modes include a hydraulic braking mode corresponding to the braking control mode, an idle speed mode corresponding to the idle speed control mode, and a drive mode corresponding to the drive control mode.

[0076] Furthermore, the control mode decision module can be configured to: based on vehicle operating data, when it is determined that the vehicle triggers an escape condition designed for potholes or bumps during downhill driving, output an escape flag signal. The escape conditions include situations where the vehicle is blocked on undulating downhill roads, situations where the vehicle's driving resistance is too high on small downhill sections of high-resistance terrain, and situations where the driver instructs the vehicle to accelerate on a small downhill section but the acceleration is insufficient; responding to the escape flag signal, force the vehicle to exit the hydraulic braking mode or idle mode and switch to the drive mode; and transmit the control mode signal to the torque loop module so that the torque loop module adjusts the torque calculation logic according to the control mode signal.

[0077] The control mode decision module described in this application, based on the vehicle control mode determined by the acceleration loop module, combines vehicle operation data to complete the decision on the system control mode. At the same time, it sets targeted rules for handling difficult situations, making the system control mode more adaptable to complex off-road escaping scenarios and improving the vehicle's off-road passability.

[0078] Specifically, firstly, the control modes include a hydraulic braking mode corresponding to the braking control mode, an idle speed mode corresponding to the idle speed control mode, and a drive mode corresponding to the drive control mode. These three control modes correspond one-to-one with the three control methods determined by the acceleration loop module, which further refines the vehicle control mode and makes the torque control of the system more targeted.

[0079] Secondly, the control mode decision module is configured to output a traction flag signal when it is determined that the vehicle has triggered a traction condition set for potholes or bumps during the descent, based on vehicle operation data. The traction conditions include the vehicle being blocked on the undulating road surface, the vehicle having excessive driving resistance on a small descent in high-resistance terrain, and the driver instructing the vehicle to accelerate on a small descent but the acceleration is insufficient.

[0080] In some embodiments of this application, the triggering conditions for the vehicle being stopped on a downhill undulating road surface are: the actual vehicle speed is less than 0.3 km / h, the slope is between -20% and 0%, the difference between the actual vehicle speed and the target speed is greater than 1 km / h, the driving torque output by the torque control module is greater than -20 Nm, and the duration of no braking torque output by the torque control module is greater than 1 second. The exiting conditions are: the difference between the actual vehicle speed and the target speed is less than 0.5 km / h or the slope is greater than or equal to 0%.

[0081] In this embodiment, the triggering conditions for the excessive vehicle driving resistance on a small downhill slope with high resistance terrain are as follows: the absolute difference between the PID calculated torque and the slope resistance torque is greater than 10 Nm; the driver does not brake and overtakes; the difference between the actual vehicle speed and the target vehicle speed is greater than 1 km / h; the slope is less than 0 percent; the torque control module does not output braking torque; the actual vehicle speed is less than 0.3 km / h; and the driving torque output by the torque control module is greater than -20 Nm. The duration of all the above conditions being met is greater than 1 second. The exit condition is that the difference between the actual vehicle speed and the target vehicle speed is less than 0.5 km / h or the slope is greater than or equal to 0 percent.

[0082] In this embodiment, the triggering condition for the driver's instruction to accelerate the vehicle on a small downhill slope but the acceleration is insufficient is that the duration of the slope being between -5% and 0% is greater than 0.5 seconds, the difference between the actual vehicle speed and the target vehicle speed is greater than 2 kilometers per hour, and the driver inputs an acceleration command. The exit condition is that the difference between the actual vehicle speed and the target vehicle speed is less than 0.5 kilometers per hour or the slope is greater than or equal to 0%.

[0083] The above three extrication conditions are all situations where vehicles are prone to getting stuck while going downhill. The control mode decision module collects operating data such as vehicle speed, slope, torque, and operating commands to accurately determine whether the vehicle has triggered the above extrication conditions. For example, when it is determined that the vehicle is stuck on an undulating downhill road, it will simultaneously collect data such as the vehicle's actual speed, slope range, speed difference, and torque output status. Only when all data meet the preset triggering conditions will it be determined that the vehicle has triggered the extrication condition and an extrication flag signal will be output.

[0084] Furthermore, the control mode decision module is configured to force the vehicle to exit the hydraulic braking mode or idle mode and switch to drive mode in response to the traction flag signal. This rule allows the system to break the conventional correspondence between control mode and control method when it detects that the vehicle is stuck on a downhill traction condition, and force the system to switch to drive mode to apply driving force to the vehicle. For example, if the vehicle is stuck in a pothole on an undulating downhill road, the acceleration loop module determines that the control mode is braking control mode, and the system is in hydraulic braking mode. After the control mode decision module determines that the vehicle has triggered the traction condition, it outputs the traction flag signal, forcing the system to exit the hydraulic braking mode and switch to drive mode to provide driving force to the vehicle and allow it to get out of the pothole.

[0085] Finally, the control mode decision module is configured to transmit the control mode signal to the torque loop module, so that the torque loop module adjusts the torque calculation logic according to the control mode signal. Different control modes correspond to different torque calculation logics. After receiving the control mode signal, the torque loop module automatically switches to the corresponding calculation logic to complete the calculation of machine drive torque or machine braking torque. For example, when receiving a drive mode signal, the torque loop module uses the drive torque calculation logic; when receiving a hydraulic braking mode signal, the torque loop module uses the braking torque calculation logic.

[0086] Based on the above solution, by setting three control modes corresponding to the vehicle control method, the torque calculation of the system becomes more targeted. At the same time, in response to the problem of vehicles getting stuck during downhill driving, three extrication conditions are set up, and rules for forcibly switching to drive mode are formulated. This allows the system to accurately identify the vehicle's extrication needs and apply driving force to the vehicle in a timely manner. This effectively solves the problem that existing off-road crawl control technology cannot respond in time when the vehicle is stuck, improves the vehicle's off-road extrication ability, and allows the system's control mode to adapt to complex off-road conditions, avoiding vehicle getting stuck due to road obstacles. This improves the system's adaptability to complex off-road scenarios and the accuracy of crawl control.

[0087] In this application, the hydraulic braking mode may include an initial braking state mode, a first braking transition state mode, a second braking transition state mode, and a cornering braking state mode. For example, in a specific embodiment, when the vehicle enters the hydraulic braking mode, it first enters the initial braking state. When the desired acceleration is greater than or equal to zero and the vehicle is in sand or mud mode, or when the duration of the desired acceleration being greater than or equal to zero is greater than 0.03 seconds and a get-out-of-trouble flag signal is received, the vehicle switches from the initial braking state to the first braking transition state and simultaneously switches to the drive mode. When the S-curve flag signal is triggered, the vehicle switches from the initial braking state to the cornering braking state. When the S-curve release flag signal is triggered and the slope is not downhill, or when an get-out-of-trouble flag signal is received, the vehicle switches from the cornering braking state to the second braking transition state. When the duration of the desired acceleration being greater than or equal to zero is greater than 0.03 seconds and the slope is not downhill, the vehicle switches from the initial braking state to the second braking transition state and simultaneously switches to the drive mode.

[0088] In this application, the torque loop module can be configured to calculate the machine drive torque or the machine braking torque through a fusion of feedforward control and feedback control. The feedforward control includes braking feedforward control and drive feedforward control. The braking feedforward control calculates the machine braking torque according to the vehicle's longitudinal dynamics equation, and the drive feedforward control calculates the machine drive torque according to a set vehicle speed-gradient torque correspondence table. The feedback control uses an incremental PID controller, which calculates a torque correction value based on the error between the desired acceleration and the actual vehicle acceleration.

[0089] The torque loop module of this application serves as the final calculation unit for machine torque. It can use a combination of feedforward control and feedback control to calculate the machine's drive torque or braking torque. At the same time, it sets up exclusive torque processing rules for driver overtaking operations, so that the torque calculation has both fast response and accurate correction capabilities, while ensuring the smoothness of torque output during driver overtaking operations.

[0090] Specifically, feedforward control is a predictive control method that can calculate torque without waiting for errors to occur, resulting in a fast response speed. Braking feedforward control is based on calculations using the vehicle's longitudinal dynamics equations. The expression for these equations can be: (2) in, As the driving force, For rolling resistance, For slope resistance, For air resistance, To increase resistance, To drive torque, For the weight of the whole vehicle, The rolling resistance coefficient, For slope, The air drag coefficient, For vehicle speed, For the overall vehicle quality, This is the rotational mass conversion factor. For acceleration, For the wheel radius, The reduction ratio of the main reducer, For transmission efficiency.

[0091] As can be seen, the vehicle longitudinal dynamics equation reflects the balance of various forces during vehicle operation, and can accurately calculate the required braking torque based on parameters such as vehicle weight, wheel radius, slope, and vehicle speed.

[0092] In this application, the drive feedforward control can be calculated based on a preset vehicle speed, slope, and torque correspondence table. This table is obtained through actual vehicle test calibration and records the corresponding drive torque values ​​at different vehicle speeds and slopes. The torque loop module can directly retrieve the corresponding drive torque value based on the current vehicle speed and slope, resulting in high calculation efficiency.

[0093] In this application, the feedback control is a real-time correction control method. It continuously collects the error between the desired acceleration and the actual vehicle acceleration using an incremental PID controller. Based on this error, it calculates a torque correction value in real time, fine-tuning the torque calculated by the feedforward control to make the final machine torque more closely match the vehicle's actual driving needs. For example, if the machine drive torque calculated by the feedforward control is 90 Nm, and the torque correction value calculated by the incremental PID controller based on the acceleration error is 5 Nm, then the final machine drive torque output by the torque loop module is 95 Nm.

[0094] In this application, the mathematical principle of the incremental PID can be: (3) In the formula, This is the proportionality coefficient. Subtract the previous error from the current error. The integral coefficient is... is the differential coefficient.

[0095] In this application, when the override module in the torque arbitration module is in a partial override state or a full override state, the torque loop module is disabled by the incremental PID controller, and only the feedforward control is retained; when the driver's override operation ends, the torque loop module is set with dual limit rules for the vehicle's deceleration process, including an acceleration limit and a torque limit.

[0096] In this application, the override module is a core sub-module of the torque arbitration module, used to determine the control ownership between driver operation and system automatic control. When in a partial or full override state, it indicates that the driver has a clear operational intention. At this time, the incremental PID controller is disabled, and only the feedforward control is retained. This can avoid torque abrupt changes caused by real-time correction of feedback control and ensure the smoothness of torque output during driver operation. When the driver's override operation ends, the system regains control. At this time, in order to avoid jerking during vehicle deceleration, an acceleration limit and a torque limit are set. For example, the deceleration acceleration limit is set to -0.4 m / s², and the braking torque limit is set to 80 Nm, making the vehicle deceleration process smoother.

[0097] Based on the above scheme, machine torque is calculated by integrating feedforward control and feedback control. Feedforward control ensures rapid response in torque calculation, allowing the system to output torque promptly based on the vehicle's driving status. Feedback control, on the other hand, corrects the calculation results of feedforward control in real time, compensating for calculation errors and making the machine torque calculation more accurate. The combination of the two achieves both fast response and high precision in torque calculation. Simultaneously, torque processing rules designed for driver overdrive operations ensure smooth torque output during manual operation, avoiding vehicle jerking caused by sudden torque changes. The dual-limiting rules after overdrive operation also make the vehicle deceleration process smoother. This ensures that the system's torque output remains smooth and precise regardless of whether it is automatically controlled or manually operated, effectively solving the problems of insufficient torque control precision and sudden changes in driving force in existing technologies, thereby improving the accuracy of vehicle off-road crawl control.

[0098] In this application, the torque arbitration module includes a override module, which can be configured to determine the control execution subject based on the manual drive torque or the manual braking torque, and the machine drive torque or the machine braking torque.

[0099] As mentioned above, the override module of the torque arbitration module, as the core unit for determining control authority, has established clear rules for determining the subject of control authority execution. At the same time, it has made a fine division of the working state, which can accurately determine the driver's operating intention and realize a smooth switch between manual operation and automatic system control.

[0100] In this application, the core judgment basis of the overdrive module is the magnitude and direction of the manual torque and the machine torque. By comprehensively judging the two, it is determined whether the current vehicle control belongs to the driver or the system.

[0101] In this application, the override module can be configured to: when the vehicle is in a first unidirectional operating condition or a second unidirectional operating condition, select the torque with the larger torque value as the basis for control execution; when the vehicle is in a first reverse operating condition or a second reverse operating condition, use the torque generated by the driver's operation as the basis for control execution.

[0102] It should be noted that the first unidirectional operating condition is the condition in which the machine driving torque and the manual driving torque coexist, the second unidirectional operating condition is the condition in which the machine braking torque and the manual braking torque coexist, the first reverse operating condition is the condition in which the machine driving torque and the manual braking torque coexist, and the second reverse operating condition is the condition in which the machine braking torque and the manual driving torque coexist.

[0103] To enable those skilled in the art to better distinguish between the aforementioned first unidirectional operating condition, second unidirectional operating condition, first reverse operating condition, and second reverse operating condition, this application makes the following definitions: The first unidirectional working condition is defined as "machine + human + working condition". When the machine is crawling, the driver presses the drive pedal. At this time, the system outputs the machine drive torque and the driver presses the accelerator to generate the manual drive torque. Both are torques that drive the vehicle. For example, the machine drive torque is 70 Nm and the manual drive torque is 90 Nm. At this time, the manual drive torque with the larger torque value is selected as the basis for control execution, and the driver takes over the vehicle drive control. The second unidirectional working condition is defined as "machine-human-working condition", that is, when the machine is crawling and braking, the driver presses the brake pedal. At this time, the system outputs machine braking torque, and the driver presses the brake to generate manual braking torque. Both are the torques that brake the vehicle. For example, the machine braking torque is 60 Nm and the manual braking torque is 80 Nm. At this time, the manual braking torque with the larger torque value is selected as the basis for control execution, and the driver takes over the vehicle braking control. The first reverse working condition is defined as "machine + human - working condition", that is, when the machine is crawling, the driver presses the brake pedal. At this time, the driver has a clear braking intention. Regardless of the size of the manual braking torque, the manual braking torque is used as the basis for the execution of control. For example, if the machine driving torque is 80 Nm and the manual braking torque is 50 Nm, the manual braking torque of 50 Nm is still selected as the basis for the execution of control. The second reverse working condition is defined as "machine-human + working condition", that is, when the machine is in a creeping braking state, the driver presses the drive pedal. At this time, the driver has a clear driving intention. Regardless of the size of the manual drive torque, the manual drive torque is used as the basis for the execution of control. For example, if the machine braking torque is 70 Nm and the manual drive torque is 40 Nm, the manual drive torque of 40 Nm is still selected as the basis for the execution of control.

[0104] See Figure 4The diagram shows the working state distribution of the overdrive module in an embodiment of this application.

[0105] In this application, the override module operates in three states: non-responsive, partially override, and fully override. These three states are determined based on the relationship between the torque value generated by the driver's operation and a set threshold, accurately reflecting the strength of the driver's intention. The state determination rules for different operating conditions are adapted to the corresponding operating scenarios, as detailed below: The non-responsive state occurs when the torque generated by the driver's operation of the accelerator or brake pedal is less than a first preset threshold. In this state, the vehicle's off-road crawl control system maintains autonomous control. In this state, the driver's intention to operate is weak, and the system ignores the driver's slight actions, continuing to maintain autonomous control. For example, if the first preset threshold is 20% of the machine torque, and the machine's driving torque is 100 Nm while the driver's manual driving torque is 15 Nm, the override module is in a non-responsive state because the manual driving torque is less than the first preset threshold.

[0106] The partial overdrive state refers to a state where, when the torque value generated by the driver's operation of the accelerator or brake pedal is between the first and second set thresholds, only the target vehicle speed is adjusted, and the torque is autonomously controlled by the vehicle's off-road crawl control system. In this state, the driver has some operational intention, but has not reached the point of completely taking over the vehicle. The system only responds to the driver's speed adjustment needs, and the torque calculation and output are still completed by the system. For example, in "machine + human + working condition" and "machine-human-working condition", the first set threshold is 20% of the torque value output by the torque control module, and the second set threshold is 100% of the torque value output by the torque control module. In "machine-human + working condition", an accelerator pedal opening of less than 5% is a non-responsive state, and an accelerator pedal opening of 5% or more is a partial overdrive state.

[0107] The fully override state refers to a state where the torque generated by the driver's operation of the accelerator or brake pedal exceeds the second preset threshold, at which point the driver completely takes over vehicle control. In this state, the driver has a strong intention to operate the system, and the system completely transfers control of the vehicle to the driver, who then controls the vehicle's torque output through pedal operation. For example, if the second preset threshold is 100% of the machine torque, and the machine-driven torque is 100 Nm while the manual-driven torque is 120 Nm, the override module is in a fully override state. Furthermore, in machining operations with fewer personnel, the override module's operating state will be directly determined to be in a fully override state, prioritizing the driver's braking intentions.

[0108] In one embodiment of this application, the following hysteresis handling rules may also be set in the "machine-human-working condition": When the torque value generated by the driver's operation is greater than 20% of the torque value output by the torque control module, the system transitions from the unresponsive state to the partial overdrive state. When the torque value generated by the driver's operation is less than 12% of the torque value output by the torque control module, the system exits from the partial overdrive state to the unresponsive state. When the torque value generated by the driver's operation is greater than 100% of the torque value output by the torque control module, the driver transitions from the partial overdrive state to the full overdrive state. When exiting the fully overdrive state, if the torque value remains in the range of 60% to 100% of the torque value output by the torque control module for more than 1 second during the process of the driver releasing the pedal, the vehicle will first enter the partial overdrive state to adjust the speed and then exit to the unresponsive state. If the dwell time is less than 1 second, the vehicle will directly exit to the unresponsive state.

[0109] Based on the above scheme, the overdrive module determines the control execution subject by considering the direction and magnitude of the manual torque and machine torque. This allows for precise judgment of the driver's operational intentions, ensuring that the allocation of control is more aligned with the driver's actual operational needs. Furthermore, the module categorizes the operating state into three states: non-responsive, partial overdrive, and full overdrive. This enables refined control allocation based on the strength of the driver's operational intentions, avoiding the abrupt switching between driver operation and automatic system control found in existing technologies. This achieves a smooth transition between manual operation and automatic system control. Additionally, the non-responsive rule for minor operations prevents driver errors or slight manipulations from interfering with the system's autonomous control, making the system more stable and thus improving the accuracy and smoothness of the vehicle's off-road crawl control.

[0110] In this application, the torque arbitration module outputs a target drive torque or a target braking torque to the vehicle actuator. The arbitrated target drive torque or target braking torque can be transmitted to the vehicle actuator via the vehicle CAN bus. The vehicle actuator includes a drive motor and an electro-hydraulic braking system. The drive motor outputs driving force according to the arbitrated drive torque, and the electro-hydraulic braking system outputs braking force according to the arbitrated braking torque.

[0111] Based on the same inventive concept, this application also provides a vehicle, see reference. Figure 5 The diagram shows a structural schematic of a vehicle in an embodiment of this application. The vehicle includes one or more memories 504, one or more processors 502, and at least one computer program (computer program instruction) stored in the memory 504 and executable on the processor 502. When the processor 502 executes the computer program, it implements the method steps in the vehicle off-road crawl control system as described above.

[0112] Among them, Figure 5In this document, a bus architecture (represented by bus 500) is used. Bus 500 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 502 and memory represented by memory 504. Bus 500 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 505 provides an interface between bus 500 and receiver 501 and transmitter 503. Receiver 501 and transmitter 503 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 502 is responsible for managing bus 500 and general processing, while memory 504 can be used to store data used by processor 502 during operation.

[0113] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0115] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0116] When the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the method steps in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0117] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A vehicle crawl control system, characterized by, The system includes: The human-computer interaction module is configured to receive a vehicle speed adjustment command or an off-road mode selection command triggered by the driver, wherein the vehicle speed adjustment command includes an acceleration command and a deceleration command. A torque control module, which is communicatively connected to the human-machine interaction module, is configured to: receive the vehicle speed adjustment command or the off-road mode selection command, and receive vehicle operating data, and calculate the machine drive torque or machine braking torque according to the vehicle speed adjustment command or the off-road mode selection command and the vehicle operating data. The torque arbitration module is communicatively connected to the torque control module and the vehicle actuator. It is configured to receive the machine drive torque or the machine braking torque, as well as the manual drive torque or manual braking torque generated by the driver's operation, and perform torque arbitration in combination with the vehicle operation data, and output the target drive torque or target braking torque to the vehicle actuator to control the vehicle actuator to drive or brake the vehicle.

2. The system according to claim 1, characterized in that, The torque control module includes a vehicle speed adjustment module, an acceleration loop module, a control mode decision module, and a torque loop module that are interconnected. The vehicle speed adjustment module is configured to adjust the target vehicle speed according to the vehicle speed adjustment command or the off-road mode selection command. The acceleration loop module is configured to: calculate the desired acceleration based on the actual vehicle speed and the target vehicle speed, and determine the vehicle control mode based on the desired acceleration; The control mode decision module is configured to: determine the control mode of the vehicle off-road crawl control system based on the vehicle control method and the vehicle operation data; The torque loop module is configured to calculate the machine drive torque or the machine braking torque based on the control mode and the desired acceleration.

3. The system according to claim 2, characterized in that, The vehicle speed adjustment module has multiple built-in set vehicle speeds and initial vehicle speeds set for different off-road modes. The vehicle speed adjustment module is configured as follows: The vehicle's actual speed is rounded up according to the acceleration command to match the corresponding set speed as the vehicle's target speed; or... The vehicle's actual speed is rounded down according to the speed reduction command to match the corresponding set speed as the vehicle's target speed; or... The initial vehicle speed is matched with the off-road mode specified by the off-road mode selection command as the target vehicle speed.

4. The system according to claim 3, characterized in that, The acceleration loop module is configured as follows: The expected acceleration of the vehicle at the actual vehicle speed is calculated based on the difference between the actual vehicle speed and the target vehicle speed. Based on the pre-calibrated acceleration reference curve, the idle speed trigger boundary and the braking trigger boundary are determined. The acceleration reference curve is a quadratic function curve, used to characterize the relationship between vehicle speed and acceleration during vehicle coasting in gear. The braking trigger boundary is smaller than the idle speed trigger boundary, and the idle speed trigger boundary is less than 0. Based on the relationship between the desired acceleration and the idle speed trigger boundary and the braking trigger boundary, one of the drive control mode, idle speed control mode and braking control mode is selected as the vehicle control mode.

5. The system according to claim 4, characterized in that, The acceleration loop module is also configured to: When the vehicle is running in drive control mode, if the desired acceleration is less than the idle speed trigger boundary, the idle speed control mode is selected as the vehicle control mode. When the vehicle is running in idle speed control mode, if the desired acceleration is less than the braking trigger boundary, the braking control mode is selected as the vehicle control mode. When the vehicle is operating in braking control mode, if the desired acceleration is greater than 0 and the duration is greater than the set duration, the drive control mode is selected as the vehicle control mode.

6. The system according to claim 5, characterized in that, The control modes include a hydraulic braking mode corresponding to the braking control mode, an idle speed mode corresponding to the idle speed control mode, and a drive mode corresponding to the drive control mode; the control mode decision module is configured as follows: Based on vehicle operation data, when it is determined that the vehicle has triggered a traction control condition set for potholes or bumps during the descent, a traction control flag signal is output. The traction control conditions include the vehicle being blocked on the undulating road surface, the vehicle having excessive driving resistance on a small descent in high-resistance terrain, and the driver instructing the vehicle to accelerate on a small descent but the acceleration is insufficient. In response to the distress signal, the vehicle is forced to exit the hydraulic braking mode or idle mode and switch to the drive mode. The control mode signal is transmitted to the torque loop module so that the torque loop module adjusts the torque calculation logic according to the control mode signal.

7. The system according to claim 6, characterized in that, The torque ring module is configured as follows: The machine's driving torque or braking torque is calculated by fusing feedforward control and feedback control. The feedforward control includes braking feedforward control and driving feedforward control. The braking feedforward control calculates the machine's braking torque based on the vehicle's longitudinal dynamics equations. The driving feedforward control calculates the machine's driving torque based on a set speed-gradient-torque correspondence table. The feedback control uses an incremental PID controller, which calculates a torque correction value based on the error between the desired acceleration and the vehicle's actual acceleration. When the override module in the torque arbitration module is in a partial or full override state, the torque loop module is disabled by the incremental PID controller, and only the feedforward control is retained; after the driver's override operation ends, the torque loop module is set with dual limit rules for the vehicle's deceleration process, including an acceleration limit and a torque limit.

8. The system according to claim 7, characterized in that, The torque arbitration module includes a override module, which is configured to: The control authority is determined based on the manual drive torque or the manual braking torque, and the machine drive torque or the machine braking torque. When the vehicle is in the first same-direction operating condition or the second same-direction operating condition, the torque with the larger torque value is selected as the basis for executing the control authority; wherein, the first same-direction operating condition is the condition in which the machine drive torque and the manual drive torque exist simultaneously, and the second same-direction operating condition is the condition in which the machine braking torque and the manual braking torque exist simultaneously. When the vehicle is in a first reverse working condition or a second reverse working condition, the torque generated by the driver's operation is used as the basis for the execution of control; wherein, the first reverse working condition is a working condition in which the machine driving torque and the manual braking torque coexist, and the second reverse working condition is a working condition in which the machine braking torque and the manual driving torque coexist.

9. The system according to claim 8, characterized in that, The operating states of the overdrive module include: In a non-responsive state, the vehicle off-road crawl control system maintains autonomous control when the torque value generated by the driver operating the accelerator pedal or brake pedal is less than a first set threshold. Partial overdrive state, which is a state in which the torque value generated by the driver operating the accelerator pedal or brake pedal is between the first set threshold and the second set threshold, and only the target speed of the vehicle is adjusted and the torque is autonomously controlled by the vehicle off-road crawl control system. Fully overdrive state, which is a state in which the driver completely takes over the control of the vehicle when the torque value generated by the driver operating the accelerator pedal or brake pedal is greater than the second set threshold.

10. A vehicle, characterized in that, The vehicle is equipped with a vehicle off-road crawl control system as described in any one of claims 1 to 9.

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