Hilly and mountain tractor unit stability cooperative control system

Abstract

The invention discloses a hill and mountain tractor unit stability cooperative control system which comprises a state sensing module, a decision analysis module, a cooperative control module and a feedback adjustment module. The state sensing module is used for monitoring operation parameters of the tractor unit; the decision analysis module is used for performing comparative analysis on the received operation parameters and an estimated stability boundary to generate a stability risk assessment result; the cooperative control module is used for analyzing the stability risk assessment result and generating a cooperative distribution instruction for engine power and four-wheel braking force; and the feedback adjustment module is used for re-monitoring the stability state of the tractor unit after the collaborative distribution instruction is executed, generating an adjustment effectiveness index and feeding back the adjustment effectiveness index to the decision analysis module, and the decision analysis module triggers optimization of a control strategy. According to the embodiment, the engine power and the four-wheel braking force are cooperatively controlled, a multi-dimensional stability intervention mechanism is formed, the control efficiency is high, and the response speed is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tractor stability control, in particular to a hill and mountain land tractor unit stability collaborative control system. BACKGROUND

[0002] Hill and mountain land is an important agricultural resource in China, but its complex terrain and large slope changes have high requirements for the passability and stability of agricultural machinery. The twist waist tractor improves the adhesion performance by the relative swing of the front and rear frames on uneven ground, but also introduces new stability problems: the swing posture will cause dynamic changes in the mass center, traction point and stress state of the machine unit, making the traditional stability control method based on rigid vehicle body ineffective.

[0003] In the prior art, the stability control of the tractor mainly focuses on the adjustment of a single mechanism, such as the position control of the hydraulic suspension or the power control of the engine, and lacks comprehensive perception of the overall vehicle dynamics and collaborative intervention of multiple actuators. When working on a slope and encountering sudden soil resistance or terrain excitation, the existing system is difficult to coordinate the distribution of power and braking force in a timely and accurate manner, and cannot effectively suppress the risk of longitudinal slip or lateral rollover that may occur. SUMMARY

[0004] In view of the foregoing defects in the existing tractor stability control, the purpose of the present application is to provide a hill and mountain land tractor unit stability collaborative control system.

[0005] To achieve the foregoing purpose, the technical solution adopted by the present application is as follows: a hill and mountain land tractor unit stability collaborative control system, comprising a state perception module, a decision analysis module, a collaborative control module and a feedback adjustment module; The state perception module is used to monitor the operating parameters of the tractor unit and send the operating parameters to the decision analysis module; The decision analysis module is used to compare and analyze the operating parameters with the stability boundaries dynamically estimated by the longitudinal-vertical-horizontal coupled dynamics model, generate a stability risk assessment result, and send the stability risk assessment result to the collaborative control module; The collaborative control module is used to analyze the stability risk assessment result, generate a collaborative distribution instruction for the engine power and four-wheel braking force, and send the collaborative distribution instruction to the actuator; The feedback adjustment module is used to re-monitor the stability state of the tractor unit after the execution of the collaborative distribution instruction, compare the re-monitoring result with the stability risk assessment result, generate an adjustment effectiveness index and feed the adjustment effectiveness index back to the decision analysis module, and trigger the optimization of the control strategy by the decision analysis module.

[0006] Further, the state perception module comprises an inertial measurement unit, a force sensor and an angle sensor, a wheel speed sensor and an engine control unit, and the operation parameters of the tractor unit comprise body attitude parameters, implement connection parameters and driving condition parameters. The inertial measurement unit obtains the body attitude parameters representing the roll, pitch and yaw states of the tractor. The force sensor and the angle sensor obtain the implement connection parameters representing the force and relative angle of the hinged point of the suspended implement and the tractor. The wheel speed sensor and the engine control unit obtain the driving condition parameters representing the driving speed and real-time torque of the driving wheels of the tractor.

[0007] Further, the decision analysis module generates the stability risk assessment result by the following method: based on the received operation parameters, the decision analysis module calculates the stability boundary of the tractor unit in real time through the built-in longitudinal-vertical-horizontal coupling dynamics model; The real-time operation parameters are compared and analyzed with the corresponding stability boundary calculated, and when the real-time parameters approach or exceed the stability boundary, the corresponding instability risk index is generated, and the type and grade of the instability risk index are determined.

[0008] Further, the cooperative control module generates the cooperative allocation instruction in the following specific manner: According to the type and grade of the received instability risk index, a preset control rule library is called; According to the preset control rule library, a feedforward-feedback compound control strategy is adopted to calculate the engine power adjustment amount required to suppress instability and the target braking torque of each wheel, and a cooperative allocation instruction is generated.

[0009] Further, the feedback adjustment module generates the adjustment effectiveness index by the following method: After the cooperative allocation instruction is executed for a set time, the latest operation parameters of the tractor unit uploaded by the state perception module are obtained; The latest operation parameters are input into the decision analysis module again for stability boundary calculation and risk assessment; If the original instability risk index is weakened or disappeared, it is determined that the adjustment is effective; if the original instability risk index is not weakened or a new risk index appears, it is determined that the adjustment is ineffective; The determination result is fed back to the decision analysis module as the adjustment effectiveness index.

[0010] The foregoing hill and mountain tractor unit stability cooperative control system can obtain the following beneficial effects: 1. The present application realizes comprehensive and real-time monitoring of the stability state of the tractor unit through multi-source information fusion perception, and provides a data basis for precise control.

[0011] 2. This invention forms a multi-dimensional stability intervention mechanism by coordinating the control of engine power and four-wheel braking force, resulting in high control efficiency and fast response speed.

[0012] 3. This invention introduces a closed-loop feedback adjustment mechanism, which can automatically verify and optimize the effectiveness of the control strategy, thereby improving the system's adaptability and robustness.

[0013] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a flowchart of the stability collaborative control system for hilly and mountainous tractor units of the present invention; Figure 2 This is a schematic diagram of the working process of the hilly and mountainous tractor unit stability collaborative control system of the present invention. Detailed Implementation

[0015] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0016] Please see Figure 1 This embodiment provides a stability collaborative control system for tractor units in hilly and mountainous areas, comprising a state perception module, a decision analysis module, a collaborative control module, and a feedback adjustment module. The status awareness module is used to monitor the operating parameters of the tractor unit and send the operating parameters to the decision analysis module; Specifically, the state perception module, as the system's input, collects operational parameters such as the tractor unit's attitude, implement connection status, and driving conditions through an inertial measurement unit (IMU) located on the vehicle body, six force / angle sensors mounted at the suspension hinge points, wheel speed sensors mounted on the wheel hubs of the four tractor wheels, an engine control unit (ECU) mounted on the frame crossbeam in the tractor's engine compartment, and the vehicle's CAN bus. Specifically, the inertial measurement unit acquires attitude parameters characterizing the tractor's roll, pitch, and yaw states; the force and angle sensors acquire implement connection parameters characterizing the forces and relative angles between the suspended implements and the tractor's hinge points; the wheel speed sensors and the engine control unit acquire driving condition parameters characterizing the tractor's speed and real-time torque of the drive wheels. The wheel speed sensors can also be located near the brake discs, with wheel speed sensors installed on both the front and rear wheels to ensure independent acquisition of the four wheel speeds and support coordinated braking force distribution; the engine control unit can also be mounted on a fixed bracket on the engine block.

[0017] The decision analysis module is used to compare and analyze the operating parameters with the stability boundary dynamically predicted by the vertical-horizontal coupled dynamic model, generate stability risk assessment results, and send the stability risk assessment results to the collaborative control module. Specifically, after receiving the operating parameters of the tractor unit, the core of the decision analysis module lies in calling the built-in longitudinal-vertical-lateral coupled dynamic model. This model is based on the Newton-Euler equations of the tractor unit and uses the folding, torsional, and swaying angles as key state variables to dynamically describe the changes in the center of mass position, traction point force, and inertial load, thereby calculating the longitudinal and lateral stability boundaries of the tractor unit in real time. By comparing the current state with these dynamic boundaries, the module accurately generates a stability risk assessment result.

[0018] Furthermore, the method for the decision analysis module to generate stability risk assessment results is as follows: Based on the received operating parameters, the decision analysis module calculates the stability boundary of the tractor unit in real time through the built-in longitudinal-vertical-lateral coupled dynamic model. The stability boundary includes the longitudinal stability boundary and the lateral stability boundary. The longitudinal stability boundary includes the longitudinal limit tilt angle and the longitudinal slip angle, and the lateral stability boundary includes the lateral tilt angle and the lateral sideslip angle. The decision analysis module compares and analyzes the real-time operating parameters with the calculated corresponding stability boundaries. When the real-time parameters approach or exceed the stability boundaries, it generates corresponding instability risk indicators and determines the type and level of the instability risk indicators.

[0019] Specific instability risk indicators include horizontal instability risk indicators and vertical instability risk indicators, which are classified into high, medium and low levels.

[0020] The collaborative control module is used to analyze the stability risk assessment results, generate collaborative allocation instructions for engine power and four-wheel braking force, and send the collaborative allocation instructions to the actuators.

[0021] Furthermore, the specific method by which the collaborative control module generates collaborative allocation instructions is as follows: The collaborative control module calls the preset control rule library according to the type and level of the received instability risk indicators; Based on the control rule base, the collaborative control module uses a feedforward-feedback composite control strategy to calculate the engine power adjustment required to suppress instability and the target braking torque of each wheel, and generates collaborative allocation instructions.

[0022] Specifically, based on the type and level of instability risk indicators, and according to a preset control rule library (e.g., high-risk lateral instability prioritizes triggering braking on the downhill side wheels and reducing engine power), the optimal allocation scheme of engine power and four-wheel braking force is calculated, and a coordinated allocation command is generated. This coordinated allocation command is then sent to the tractor's actuators (such as the engine ECU and electronic braking system EBS) to initiate the action.

[0023] The feedback adjustment module is used to re-monitor the stability status of the tractor unit after the execution of the collaborative allocation command, compare the re-monitoring results with the stability risk assessment results, generate adjustment effectiveness indicators, and feed the adjustment effectiveness indicators back to the decision analysis module, which then triggers the optimization of the control strategy.

[0024] Furthermore, the method for the feedback adjustment module to generate adjustment effectiveness indicators is as follows: After a set time has elapsed since the collaborative allocation command was executed, the latest operating parameters of the tractor unit uploaded by the status perception module are obtained. The set time is 0.1-1 seconds, and this set time range is based on the tractor's power response characteristics and the braking system action delay calibration. The latest operating parameters are then input into the decision analysis module for stability boundary calculation and risk assessment. If the original instability risk indicator weakens or disappears, the adjustment is deemed effective; if the original instability risk indicator does not weaken or a new risk indicator appears, the adjustment is deemed ineffective. The judgment result is fed back to the decision analysis module as an indicator of the effectiveness of regulation.

[0025] Specifically, after the collaborative allocation instruction is executed, the feedback adjustment module obtains the latest system status again through the status awareness module and submits it to the decision analysis module for secondary evaluation. The adjustment effectiveness indicators (such as "risk level downgraded from high to medium") are fed back to the decision layer to decide whether to maintain the current strategy or start optimization, thus forming a complete adaptive optimization closed loop.

[0026] Please see Figure 2 The working process of the stability collaborative control system for hilly and mountainous tractor units of the present invention is as follows: First, the state perception module collects various operating parameters of the tractor unit in real time. These parameters are then sent to the decision analysis module, whose core task is to dynamically diagnose instability risks, specifically determining whether the current state is approaching or exceeding the stability boundary. This judgment point is the system's core decision node. If the judgment is "no," indicating a stable current state, the system returns to continuously collecting and monitoring the tractor unit's operating parameters. If the judgment is "yes," indicating a detected instability risk, the system immediately enters the multi-mode collaborative control phase: the collaborative control module generates targeted engine power and four-wheel braking force collaborative distribution commands based on the specific type (longitudinal / lateral) and level (high / medium / low) of the risk assessment results, and drives the actuators to execute them. After the commands are executed, the system enters the feedback adaptive adjustment phase: the feedback adjustment module monitors the new state of the tractor unit and determines whether the adjustment is effective. If the judgment is "yes," it indicates the control strategy is effective, and the system returns to the monitoring state. If the judgment is "no", it means that the current strategy is not effective. The decision analysis module will trigger the update and optimization of the control strategy (such as switching to backup rules or adjusting control parameters), and generate instructions again based on the new strategy. This process will be repeated until the adjustment is effective. This process ensures that the system can respond quickly and intelligently suppress the instability risk in complex hilly and mountainous conditions.

[0027] The aforementioned preset thresholds, control rule parameters, etc., are pre-calibrated based on a large amount of simulation and bench test data of typical working conditions in hilly and mountainous areas, and stored in the system database. They can be matched and adjusted according to specific tractor models and agricultural implement configurations.

[0028] The aforementioned stability collaborative control system for hilly and mountainous tractor units can achieve the following beneficial effects: 1. This invention achieves comprehensive and real-time monitoring of the stability status of tractor units through multi-source information fusion sensing, providing a data foundation for precise control.

[0029] 2. This invention forms a multi-dimensional stability intervention mechanism by coordinating the control of engine power and four-wheel braking force, resulting in high control efficiency and fast response speed.

[0030] 3. This invention introduces a closed-loop feedback adjustment mechanism, which can automatically verify and optimize the effectiveness of the control strategy, thereby improving the system's adaptability and robustness.

[0031] The above description is merely a preferred embodiment of the present invention. Any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments without departing from the scope of the present invention and based on the technical essence of the present invention shall still fall within the scope of the present invention.

Claims

1. A stability collaborative control system for tractor units in hilly and mountainous areas, characterized in that, It includes a state perception module, a decision analysis module, a collaborative control module, and a feedback regulation module; The status awareness module is used to monitor the operating parameters of the tractor unit and send the operating parameters to the decision analysis module; The decision analysis module is used to compare and analyze the operating parameters with the stability boundary dynamically predicted by the vertical-horizontal coupled dynamic model, generate stability risk assessment results, and send the stability risk assessment results to the collaborative control module. The collaborative control module is used to analyze the stability risk assessment results, generate collaborative allocation instructions for engine power and four-wheel braking force, and send the collaborative allocation instructions to the actuators. The feedback adjustment module is used to re-monitor the stability status of the tractor unit after the execution of the collaborative allocation command, compare the re-monitoring results with the stability risk assessment results, generate adjustment effectiveness indicators, and feed the adjustment effectiveness indicators back to the decision analysis module, which then triggers the optimization of the control strategy.

2. The stability collaborative control system for hilly and mountainous tractor units according to claim 1, characterized in that, The state perception module includes an inertial measurement unit, force sensors and angle sensors, wheel speed sensors and engine control unit. The operating parameters of the tractor unit include body attitude parameters, implement connection parameters and driving condition parameters. The inertial measurement unit acquires the body attitude parameters characterizing the tractor's roll, pitch, and yaw states; Force and angle sensors acquire implement connection parameters that characterize the force and relative angle at the hinge point between the implement and the tractor; Wheel speed sensors and engine control units acquire driving condition parameters that characterize the tractor's speed and the real-time torque of the drive wheels.

3. The stability collaborative control system for hilly and mountainous tractor units according to claim 1, characterized in that, The method for generating stability risk assessment results by the decision analysis module is as follows: based on the received operating parameters, the stability boundary of the tractor unit is calculated in real time through the built-in longitudinal-vertical-lateral coupled dynamic model. The real-time operating parameters are compared and analyzed with the calculated corresponding stability boundaries. When the real-time operating parameters approach or exceed the stability boundaries, corresponding instability risk indicators are generated, and the type and level of the instability risk indicators are determined.

4. The stability collaborative control system for hilly and mountainous tractor units according to claim 3, characterized in that, The specific method by which the collaborative control module generates collaborative allocation instructions is as follows: Based on the type and level of the received instability risk indicators, the preset control rule library is invoked; Based on the preset control rule library, a feedforward-feedback composite control strategy is adopted to calculate the engine power adjustment required to suppress instability and the target braking torque of each wheel, and generate a coordinated distribution command.

5. The stability collaborative control system for hilly and mountainous tractor units according to claim 3, characterized in that, The method for the feedback adjustment module to generate adjustment effectiveness indicators is as follows: After a set time has elapsed since the collaborative allocation instruction was executed, the latest operating parameters of the tractor unit uploaded by the status awareness module are obtained. The latest operating parameters are then input into the decision analysis module for stability boundary calculation and risk assessment. If the original instability risk indicators weaken or disappear, the adjustment is deemed effective. If the original instability risk indicators do not weaken or new risk indicators emerge, the adjustment is deemed ineffective. The judgment result is fed back to the decision analysis module as an indicator of the effectiveness of regulation.

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