Self-adaptive braking system of hilly and mountainous region tractor
By integrating data from the adaptive braking system and implementing multi-mode control, the problem of insufficient adaptability of the braking system in tractor operations in hilly and mountainous areas has been solved, and the stability and safety of the vehicle in complex terrain have been improved, especially the optimized control when crossing slopes, making sharp turns, frequently starting on slopes, and descending long slopes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-11
- Publication Date
- 2026-04-10
AI Technical Summary
Existing tractor braking systems are unable to adapt to complex terrain in hilly and mountainous areas, resulting in problems such as the risk of rollover, inaccurate braking, low energy utilization efficiency, and high operational difficulty. They perform particularly poorly when driving on cross slopes, making sharp turns, frequently starting on slopes, and descending long slopes.
An adaptive braking system is adopted, which integrates an inertial measurement unit, wheel speed sensor and implement attitude sensor. Data fusion is performed through a central domain controller to dynamically allocate braking force and coordinate the adjustment of active attitude. Combined with electro-hydraulic braking, motor regenerative braking and active attitude adjustment mechanism, multi-mode adaptive control is achieved.
It improves the safety and efficiency of tractors operating in hilly and mountainous areas, reduces the difficulty of operation, extends the life of brakes, improves energy utilization efficiency, and ensures vehicle stability and safety under various working conditions.
Smart Images
Figure CN121822397A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of automobile auxiliary driving technology, in particular to a self-adaptive braking system of a hilly and mountainous tractor. BACKGROUND
[0002] Hilly and mountainous areas are important scenes for tractor operation in China, and the terrain characteristics are large slope change and irregular land block. When the tractor operates in these areas, it often faces the working conditions of cross slope driving, steep slope starting, sharp turning and long downhill, which puts higher requirements on the adaptability of the braking system.
[0003] At present, the tractor braking system mostly adopts traditional hydraulic braking technology, that is, the driver steps on the pedal, and the hydraulic drive wheel brake generates braking force. Although this technology can meet the basic needs of flat road, it has the following shortcomings in hilly and mountainous areas: Firstly, when driving on a cross slope, the existing system cannot sense the inclination angle of the vehicle body, and cannot dynamically adjust the braking force of each wheel according to the degree of roll. The driver can only passively decelerate to respond. After mounting the agricultural implement, the center of gravity of the whole vehicle changes, further increasing the risk of rollover.
[0004] Secondly, when starting on a slope, the driver needs to operate the clutch, brake and accelerator pedals at the same time, and improper coordination may cause rear sliding. Although some models are equipped with hydraulic slope assistance, the pressure maintaining time is limited and long-term pressure maintaining will cause brake overheating and wear, which is difficult to adapt to the operation demand of frequent slope starting.
[0005] Thirdly, when turning in a narrow land block, the traditional front wheel steering has a large turning radius at low speed, and the driver needs to advance and retreat several times to complete the turning, which is low in operation efficiency. The existing unilateral braking deceleration method needs to be manually operated and lacks control accuracy.
[0006] Fourthly, the braking system lacks terrain prediction ability, and when entering a long downhill, it can only respond after the vehicle starts to downhill and the driver steps on the pedal, which has a delay and is difficult to achieve the best braking effect.
[0007] Fifthly, the regenerative braking and hydraulic braking of new energy tractors are independently controlled, and the braking force fluctuates obviously when switching between the two, which affects the driving smoothness and safety.
[0008] In view of the above problems, existing researches have proposed radar sensing active braking, center of gravity monitoring anti-rollover and other technologies, but most of them are aimed at a single working condition, and there is still no systematic braking solution that can adapt to various complex terrains in hilly and mountainous areas. SUMMARY
[0009] In view of the deficiencies of the prior art, the present application provides a self-adaptive braking system of a hilly and mountainous tractor, which solves the problems proposed in the background art.
[0010] The application solves the above technical problems in the following manner: The application provides a self-adaptive braking system of a hilly tractor, comprising: A perception layer, comprising an inertial measurement unit, a wheel speed sensor and a farm tool posture sensor, for acquiring vehicle posture, wheel speed and farm tool load information in real time; A decision layer, comprising a central domain controller, in communication connection with the perception layer, for receiving and fusing perception layer data, deciding a corresponding braking mode based on fused data and generating a control instruction; and An execution layer, comprising an electro-hydraulic braking subsystem, an electric motor regenerative braking subsystem and an active posture adjustment mechanism, in communication connection with the decision layer, for executing the control instruction; The central domain controller is configured to execute a posture braking coupling control strategy, dynamically allocate wheel braking forces according to real-time vehicle body posture and farm tool load state and cooperatively adjust the active posture adjustment mechanism to maintain vehicle stability, according to the following formula:
[0011] In the formula, is a stable torque required to maintain vehicle stability, is the total vehicle mass, is the acceleration of gravity, is the actual center of gravity height, is the real-time roll angle, is a safety factor, is an uphill side wheel braking force, is a dynamic allocation coefficient, is a wheelbase.
[0012] On the basis of the above technical solution, the application can also be improved as follows.
[0013] Further, the central domain controller is configured to run a terrain self-adaptive braking control algorithm comprising a data fusion module, a working condition mode decision module and a control quantity calculation module, the working condition mode decision module decides a current mode to be activated from a plurality of braking modes based on fused data, the plurality of braking modes at least comprising a posture keeping mode, a side slope stability mode, a steering auxiliary braking mode, a terrain pre-charging mode and an emergency braking mode.
[0014] The beneficial effects of adopting the above further solution are as follows: Through multi-mode decision-making and switching, the system can automatically select the most suitable braking strategy based on real-time operating conditions, covering various hazardous scenarios in hilly and mountainous tractor operations, and achieving full-condition adaptive braking control. The data fusion module makes state estimation more accurate, providing a reliable basis for accurate decision-making; the operating condition mode decision-making module has built-in priority logic to ensure that emergency conditions are handled first, maximizing safety; the control quantity calculation module uses specialized control algorithms for different modes to optimize the control effect under each mode, thereby comprehensively improving the system's adaptability and safety.
[0015] Furthermore, in the attitude-maintaining mode, when the vehicle speed is zero and the pitch angle is... Furthermore, when the driver does not initiate a start operation, the central domain controller prioritizes sending a negative torque command to the motor regenerative braking subsystem:
[0016] In the formula, The target torque for the motor, For safety reasons, The wheel rolling radius is defined as follows: when the motor's reverse torque reaches its upper limit or the holding time exceeds the limit, braking pressure commands are gradually sent to the electro-hydraulic braking subsystem to achieve a smooth connection between motor reverse braking and electro-hydraulic braking.
[0017] The beneficial effects of adopting the above-mentioned further solutions are: Prioritizing the use of wear-free motor reverse braking for hill-start assist avoids the overheating and wear issues caused by prolonged pressure holding in traditional hydraulic braking, thus extending brake lifespan. When motor capacity is insufficient or battery charge is too high to recover energy, the system can engage hydraulic braking to ensure reliable parking at any slope and with any battery charge level, effectively preventing the risk of rolling back. During start-up, the coordinated control of motor torque and braking pressure achieves a smooth starting experience, reducing the driver's operational difficulty. This is especially suitable for operation scenarios involving frequent hill starts in hilly and mountainous terrain. Simultaneously, motor reverse braking can also recover energy, improving the overall energy utilization efficiency of the vehicle.
[0018] Furthermore, in the slope stabilization mode, when the roll angle is... And vehicle speed At that time, the central domain controller calculates the stabilizing torque according to the formula. The system sends an adjustment command to the active attitude adjustment mechanism to extend the suspension on the uphill side and simultaneously apply braking force to the wheels on the uphill side. Once the roll angle falls below the safe threshold, the mode will be gradually exited.
[0019] The beneficial effects of adopting the above-mentioned further solutions are: Through the combined action of active suspension lifting and uphill side braking, a stabilizing torque is actively generated to resist rollover, keeping the vehicle firmly planted on the slope. Compared to traditional methods such as speed limiting, this actively maintains the vehicle's posture, allowing the tractor to operate safely at higher speeds on steeper cross slopes. The fuzzy PID control algorithm enables rapid and smooth suspension adjustment, adapting to different slope change rates. The dynamic distribution of braking force is adjusted according to the roll angle, ensuring sufficient stabilizing torque. The introduction of implement posture sensors allows the system to correct the center of gravity height in real time, calculating stabilizing torque even when different implements are mounted.
[0020] Furthermore, in the steering assist braking mode, when the vehicle speed... Steering wheel angle And the turning angular velocity At that time, the central domain controller calculates the additional yaw moment. ;
[0021] In the formula, The moment of inertia of the vehicle's yaw motion. For the target yaw rate, This is the actual yaw rate. To control the cycle; And according to Apply braking force to the inside rear wheel during the turn:
[0022] In the formula, Wheelbase This is the allocation coefficient.
[0023] The beneficial effects of adopting the above-mentioned further solutions are: Additional yaw moment is generated by independent braking of the inner rear wheel, which reduces the turning radius of the tractor when making sharp turns at low speeds, improving maneuverability and passability. Stepped application and maximum braking force limit ensure the safety of the control process, avoiding fishtailing or driver discomfort caused by sudden braking. Coordinated control with the four-wheel steering system can further optimize the steering effect, minimizing the turning radius.
[0024] Furthermore, in the terrain pre-charging mode, when a downhill slope is detected ahead... And distance At that time, the central domain controller sends a pre-charge command to the electro-hydraulic braking subsystem to increase the pipeline pressure to the pre-charge pressure value. Simultaneously, a pre-adjustment command is sent to the motor regenerative braking subsystem to adjust the preset value of the regenerative braking intensity:
[0025] This allows the motor to enter the power generation preparation state in advance.
[0026] The beneficial effects of adopting the above-mentioned further solutions are: Terrain pre-aiming technology eliminates the lag problem caused by brake gap and motor response delay in traditional braking systems. When the vehicle actually enters a downhill slope, the braking system is already in standby mode and can provide the required braking force, shortening the braking response time and improving the safety of long downhill slopes. The pre-adjustment of regenerative braking allows the motor to enter the power generation mode in advance, increasing the vehicle's range and effectively preventing speed loss due to braking delay.
[0027] Furthermore, in the emergency braking mode, when the brake pedal opening... When a collision risk exists, the central domain controller determines the target deceleration. ,in The road surface adhesion coefficient is used; a neural network PID controller calculates the front and rear axle braking force distribution based on vehicle speed, target deceleration, and road surface type, and sends a full braking command to the electro-hydraulic braking subsystem; at the same time, the slip ratio of each wheel is monitored in real time. ,when Exceeding the seizure threshold Anti-lock braking system is achieved in real time.
[0028] The beneficial effects of adopting the above-mentioned further solutions are: Compared with the traditional fixed ratio distribution, this scheme has a stronger adaptability to different road conditions such as dry, wet, slippery, and icy / snowy surfaces. The coordinated operation of electro-hydraulic braking and regenerative braking maximizes the total braking force while recovering energy.
[0029] Furthermore, the electro-hydraulic braking subsystem includes an electro-hydraulic proportional valve and a wheel-side wet brake. The electro-hydraulic proportional valve adopts an integrated structure in which the pilot valve core is nested inside the main valve core. The bottom of the main valve core is provided with an annular buffer head and a rectangular groove, and the barrel wall has a V-shaped groove for adjusting the input current. Proportionally control braking pressure ,satisfy ,in This is the proportionality coefficient.
[0030] The beneficial effects of adopting the above-mentioned further solutions are: The integrated pilot structure of the electro-hydraulic proportional valve reduces valve body size and internal leakage, improves control accuracy and response speed, and can respond to rapid commands, providing reliable hydraulic braking force for various braking modes.
[0031] Furthermore, the active attitude adjustment mechanism includes a servo electric cylinder with linear displacement. With motor rotation angle satisfy ,in The lead of the lead screw; the servo electric cylinder is controlled by a servo driver employing a three-closed-loop control structure and an adaptive sliding mode control algorithm, with position tracking error... Satisfying the sliding mode reaching law ,in For sliding surface, and For adaptive adjustment parameters.
[0032] The beneficial effects of adopting the above-mentioned further solutions are: Servo electric cylinders replace traditional hydraulic cylinders as the actuators of active suspension, offering advantages such as fast response and energy saving. The use of planetary roller screws enables them to withstand heavy impacts during tractor operation. The three-loop control combined with adaptive sliding mode control algorithm can effectively suppress disturbances caused by uneven road surfaces, and can still accurately track the target position in rugged terrain, ensuring the accuracy and speed of vehicle attitude adjustment.
[0033] Furthermore, the central domain controller is also configured to perform smooth mode switching control, limiting the rate of change of control input when switching between different braking modes to ensure the rate of change of braking force. Suspension adjustment rate Motor torque change rate .
[0034] The beneficial effects of adopting the above-mentioned further solutions are: The smooth mode switching control effectively avoids the shock and jerking sensation caused when switching between different braking modes by limiting the rate of change of the control variables of each actuator. The fault diagnosis and degradation processing module provides the system with complete safety redundancy. In the event of a level 1 fault, the system can still provide basic braking function to ensure that the vehicle can continue to drive to the repair shop. In the event of a level 2 fault, the system reminds the driver to operate with caution by limiting the speed and issuing an alarm. In the event of a level 3 fault, the emergency parking will safely stop the vehicle and continue to issue an alarm to prevent accidents to the greatest extent possible.
[0035] Therefore, the adaptive braking system for hilly and mountainous tractors provided by this invention has the following beneficial effects: The perception layer acquires real-time information on vehicle attitude, wheel speed, and implement load through inertial measurement units, wheel speed sensors, and implement attitude sensors, providing an accurate data foundation for the system. The central domain controller in the decision layer fuses and processes the perception data, and determines the corresponding braking mode based on real-time operating conditions, enabling the system to adaptively control complex terrain. The electro-hydraulic braking subsystem, the electric regenerative braking subsystem, and the active attitude adjustment mechanism integrated in the execution layer work together to actively adjust the vehicle attitude while accurately executing braking commands, ensuring the stability of the vehicle under various operating conditions.
[0036] The attitude-braking coupled control strategy executed by the central domain controller incorporates real-time roll angle and implement load into the stabilizing torque calculation, and dynamically distributes the braking force of the uphill wheels based on the calculation results. Simultaneously, it coordinates and adjusts the active attitude adjustment mechanism to achieve deep integration of braking and attitude control. This strategy effectively suppresses the risk of vehicle rollover when traveling on a cross slope and improves the active safety of the tractor in dangerous conditions such as steep slopes and sharp bends. Attached Figure Description
[0037] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.
[0038] In the attached diagram: Figure 1 This is a schematic diagram of the overall system structure of the present invention; Figure 2 This is a schematic diagram of the sensing layer structure of the present invention; Figure 3 This is a schematic diagram of the decision-making layer structure of the present invention; Figure 4 This is a schematic diagram of the execution layer structure of the present invention. Detailed Implementation
[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0040] Please see Figures 1 to 4 As shown, the embodiments provided by the present invention are as follows: Example 1 An adaptive braking system for a hilly mountain tractor includes: The perception layer, including inertial measurement units, wheel speed sensors, and implement attitude sensors, is used to acquire vehicle attitude, wheel speed, and implement load information in real time. The decision-making layer, including the central domain controller, communicates with the perception layer to receive and fuse data from the perception layer, determine the corresponding braking mode based on the fused data, and generate control commands; and The execution layer, including the electro-hydraulic braking subsystem, the motor regenerative braking subsystem, and the active attitude adjustment mechanism, is connected in communication with the decision-making layer and is used to execute control commands. The central domain controller is configured to execute the attitude braking coupling control strategy. Based on the real-time vehicle attitude and implement load status, it dynamically distributes the braking force of each wheel according to the following formula and coordinates the active attitude adjustment mechanism to maintain vehicle stability.
[0041] In the formula, The stabilizing torque required to maintain vehicle stability, For the overall vehicle quality, It is the acceleration due to gravity. This is the actual height of the center of gravity. For real-time roll angle, For safety reasons, Braking force for the wheels on the uphill side, For dynamic allocation coefficients, Wheelbase; The central domain controller is configured to run a terrain-adaptive braking control algorithm, which includes a data fusion module, a working condition mode decision module, and a control quantity calculation module. The working condition mode decision module determines the active braking mode from multiple braking modes based on fused data. These multiple braking modes include at least attitude holding mode, slope stabilization mode, steering assist braking mode, terrain pre-charge mode, and emergency braking mode. Through multi-mode decision-making and switching, the system can automatically select the most suitable braking strategy based on real-time working conditions, covering various hazardous scenarios in hilly and mountainous tractor operations, achieving full-condition adaptive braking control. The data fusion module makes state estimation more accurate, providing a reliable basis for accurate decision-making; the working condition mode decision module has built-in priority logic to ensure that emergency conditions are handled first, maximizing safety; the control quantity calculation module uses specialized control algorithms for different modes to optimize the control effect under each mode, thereby comprehensively improving the system's adaptability and safety.
[0042] Example 2 To further illustrate this solution, for example, such as Figures 1 to 4 As shown, the present invention also includes: In attitude hold mode, when the vehicle speed is zero and the pitch angle is... Furthermore, when the driver does not initiate a start operation, the central domain controller prioritizes sending a negative torque command to the regenerative braking subsystem of the electric motor:
[0043] In the formula, The target torque for the motor, For safety reasons, The wheel rolling radius; when the motor reverse torque reaches the upper limit or the holding time exceeds the limit, the braking pressure command is gradually sent to the electro-hydraulic braking subsystem to achieve a smooth connection between motor reverse braking and electro-hydraulic braking; The system prioritizes the use of wear-free motor reverse braking for slope holding, avoiding the overheating and wear issues caused by prolonged pressure holding in traditional hydraulic braking, thus extending brake life. When the motor capacity is insufficient or the battery state of charge is too high to recover energy, the system can engage hydraulic braking to ensure reliable parking at any slope and battery level, effectively preventing the risk of rolling back. During start-up, the coordinated control of motor torque and braking pressure achieves a smooth starting experience, reducing the driver's operational difficulty, especially suitable for operation scenarios involving frequent slope starts in hilly and mountainous terrain. Simultaneously, the motor reverse braking can also recover energy, improving the overall energy utilization efficiency of the vehicle. In side slope stabilization mode, when the roll angle... And vehicle speed At that time, the central domain controller calculates the stabilizing torque according to the formula. The system sends an adjustment command to the active attitude adjustment mechanism to extend the suspension on the uphill side and simultaneously apply braking force to the wheels on the uphill side. The mode will be gradually exited once the roll angle falls below the safe threshold. Through the combined action of active suspension lifting and uphill side braking, a stabilizing torque is actively generated to resist rollover, keeping the vehicle firmly planted on the slope. Compared to traditional methods such as speed limiting, this actively maintains the vehicle's posture, allowing the tractor to operate safely at higher speeds on steeper cross slopes. The fuzzy PID control algorithm enables rapid and smooth suspension adjustment, adapting to different slope change rates. The dynamic distribution of braking force is adjusted according to the roll angle, ensuring sufficient stabilizing torque. The introduction of implement posture sensors allows the system to correct the center of gravity height in real time, calculating stabilizing torque even when different implements are mounted.
[0044] Example 3 To further illustrate this solution, for example, such as Figures 1 to 4 As shown, the present invention also includes: In steering assist braking mode, when the vehicle speed Steering wheel angle And the turning angular velocity At that time, the central domain controller calculates the additional yaw moment. ;
[0045] In the formula, The moment of inertia of the vehicle's yaw motion. For the target yaw rate, This is the actual yaw rate. To control the cycle; And according to Apply braking force to the inside rear wheel during the turn:
[0046] In the formula, Wheelbase For allocation coefficients; The independent braking of the inner rear wheel generates additional yaw moment, which reduces the turning radius of the tractor when making sharp turns at low speeds, improving maneuverability and passability. The stepped application and maximum braking force limit ensure the safety of the control process, avoiding fishtailing or driver discomfort caused by sudden braking. The coordinated control with the four-wheel steering system can further optimize the steering effect and minimize the turning radius. In terrain pre-charge mode, when a downhill slope is detected ahead... And distance At this time, the central domain controller sends a pre-charge command to the electro-hydraulic braking subsystem to raise the pipeline pressure to the pre-charge pressure value. Simultaneously, a pre-adjustment command is sent to the motor regenerative braking subsystem to adjust the preset value of the regenerative braking intensity:
[0047] This allows the motor to enter the power generation preparation state in advance; Terrain pre-aiming technology eliminates the lag problem caused by brake gap and motor response delay in traditional braking systems. When the vehicle actually enters a downhill slope, the braking system is already in standby mode and can provide the required braking force, shortening the braking response time and improving the safety of long downhill slopes. The pre-adjustment of regenerative braking allows the motor to enter the power generation mode in advance, increasing the vehicle's range and effectively preventing speed loss due to braking delay.
[0048] Example 4 To further illustrate this solution, for example, such as Figures 1 to 4 As shown, the present invention also includes: In emergency braking mode, when the brake pedal opening is... When a collision risk exists, the central domain controller determines the target deceleration. ,in The road surface adhesion coefficient is used; a neural network PID controller calculates the front and rear axle braking force distribution based on vehicle speed, target deceleration, and road surface type, and sends a full braking command to the electro-hydraulic braking subsystem; at the same time, the slip ratio of each wheel is monitored in real time. ,when Exceeding the seizure threshold Anti-lock braking system (ABS) can be implemented in a timely manner; Compared with the traditional fixed ratio distribution, this scheme has a stronger adaptability to different road surfaces such as dry, wet, slippery, and icy. The coordinated work of electro-hydraulic braking and regenerative braking maximizes the total braking force while recovering energy. The electro-hydraulic braking subsystem includes an electro-hydraulic proportional valve and wheel-side wet brakes. The electro-hydraulic proportional valve adopts an integrated structure in which the pilot valve core is nested inside the main valve core. The bottom of the main valve core is equipped with an annular buffer head and a rectangular groove, and the barrel wall has a V-shaped groove, which is used to adjust the input current. Proportionally control braking pressure ,satisfy ,in This is the proportionality coefficient; The integrated pilot structure of the electro-hydraulic proportional valve reduces valve body size and internal leakage, improves control accuracy and response speed, and can respond to rapid commands, providing reliable hydraulic braking force for various braking modes.
[0049] Example 5 To further illustrate this solution, for example, such as Figures 1 to 4 As shown, the present invention also includes: The active attitude adjustment mechanism includes a servo electric cylinder, whose linear displacement... With motor rotation angle satisfy ,in The lead of the lead screw; the servo electric cylinder is controlled by a servo driver employing a three-closed-loop control structure and an adaptive sliding mode control algorithm, with position tracking error... Satisfying the sliding mode reaching law ,in For sliding surface, and For adaptive adjustment parameters; Servo electric cylinders replace traditional hydraulic cylinders as the actuators of active suspension, offering advantages such as fast response and energy saving. The use of planetary roller screws enables them to withstand heavy impacts during tractor operation. The three-loop control combined with adaptive sliding mode control algorithm can effectively suppress disturbances caused by uneven road surfaces, and can still accurately track the target position in rugged terrain, ensuring the accuracy and speed of vehicle posture adjustment. The central domain controller is also configured to perform smooth mode switching control, limiting the rate of change of control inputs when switching between different braking modes to ensure the rate of change of braking force. Suspension adjustment rate Motor torque change rate .
[0050] The beneficial effects of adopting the above-mentioned further solutions are: The smooth mode switching control effectively avoids the shock and jerking sensation caused when switching between different braking modes by limiting the rate of change of the control variables of each actuator. The fault diagnosis and degradation processing module provides the system with complete safety redundancy. In the event of a level 1 fault, the system can still provide basic braking function to ensure that the vehicle can continue to drive to the repair shop. In the event of a level 2 fault, the system reminds the driver to operate with caution by limiting the speed and issuing an alarm. In the event of a level 3 fault, the emergency parking will safely stop the vehicle and continue to issue an alarm to prevent accidents to the greatest extent possible.
[0051] Working principle: Data Acquisition: The perception layer acquires vehicle posture, wheel speed, and implement load information in real time through inertial measurement units, wheel speed sensors, and implement attitude sensors.
[0052] Data fusion and state estimation: The central domain controller of the decision layer receives the above data and obtains high-precision vehicle state parameters after fusion processing.
[0053] Operating mode decision: Based on fused data, the operating mode decision module identifies the current operating condition and activates the corresponding braking mode.
[0054] Attitude-to-braking coupling control: In critical modes such as side slope stability, the central domain controller calculates the torque required to maintain vehicle stability based on the real-time roll angle and implement load, and dynamically distributes the braking force of the uphill wheels accordingly, while sending suspension adjustment commands to the active attitude adjustment mechanism.
[0055] Synergistic execution: The electro-hydraulic braking subsystem, the motor regenerative braking subsystem, and the active attitude adjustment mechanism in the execution layer respond synchronously to achieve precise application of braking force and active adjustment of vehicle attitude.
[0056] Closed-loop feedback: Each sensor continuously monitors the vehicle status and returns real-time data to the decision-making level to form closed-loop control until the vehicle returns to stability.
[0057] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0058] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. An adaptive braking system for a hilly and mountainous tractor, characterized in that, include: The perception layer, including inertial measurement units, wheel speed sensors, and implement attitude sensors, is used to acquire vehicle attitude, wheel speed, and implement load information in real time. The decision layer, including the central domain controller, is communicatively connected to the perception layer and is used to receive and fuse data from the perception layer, determine the corresponding braking mode based on the fused data, and generate control commands. as well as The execution layer, including the electro-hydraulic braking subsystem, the motor regenerative braking subsystem, and the active attitude adjustment mechanism, is communicatively connected to the decision-making layer and is used to execute the control commands. The central domain controller is configured to execute an attitude braking coupling control strategy, which dynamically distributes the braking force of each wheel according to the real-time vehicle attitude and implement load status, and coordinates the active attitude adjustment mechanism to maintain vehicle stability. ； In the formula, The stabilizing torque required to maintain vehicle stability, For the overall vehicle quality, It is the acceleration due to gravity. This is the actual height of the center of gravity. For real-time roll angle, For safety reasons, Braking force for the wheels on the uphill side, For dynamic allocation coefficients, This refers to the wheel track.
2. The adaptive braking system for a hilly mountain tractor according to claim 1, characterized in that: The central domain controller is configured to run a terrain-adaptive braking control algorithm that includes a data fusion module, a working condition mode decision module, and a control quantity calculation module. The working condition mode decision module determines the mode to be activated from multiple braking modes based on the fused data. The multiple braking modes include at least attitude holding mode, slope stabilization mode, steering assist braking mode, terrain pre-charge mode, and emergency braking mode.
3. The adaptive braking system for a hilly tractor according to claim 2, characterized in that: In the attitude-maintaining mode, when the vehicle speed is zero and the pitch angle is... Furthermore, when the driver does not initiate a start operation, the central domain controller prioritizes sending a negative torque command to the motor regenerative braking subsystem: ； In the formula, The target torque for the motor, For safety reasons, The radius of the wheel's rolling radius; When the motor's reverse torque reaches its upper limit or the holding time exceeds the limit, braking pressure commands are gradually sent to the electro-hydraulic braking subsystem to achieve a smooth connection between motor reverse braking and electro-hydraulic braking.
4. The adaptive braking system for a hilly tractor according to claim 2, characterized in that: In the slope stabilization mode, when the roll angle is... And vehicle speed At that time, the central domain controller calculates the stabilizing torque according to the formula. The system sends an adjustment command to the active attitude adjustment mechanism to extend the suspension on the uphill side and simultaneously apply braking force to the wheels on the uphill side. Once the roll angle falls below the safe threshold, the mode will be gradually exited.
5. The adaptive braking system for a hilly tractor according to claim 2, characterized in that: In the steering assist braking mode, when the vehicle speed Steering wheel angle And the turning angular velocity At that time, the central domain controller calculates the additional yaw moment. ; ； In the formula, The moment of inertia of the vehicle's yaw motion. For the target yaw rate, This is the actual yaw rate. To control the cycle; And according to Apply braking force to the inside rear wheel during the turn: ； In the formula, Wheelbase This is the allocation coefficient.
6. The adaptive braking system for a hilly tractor according to claim 2, characterized in that: In the terrain pre-charge mode, when a downhill slope is detected ahead... And distance At that time, the central domain controller sends a pre-charge command to the electro-hydraulic braking subsystem to increase the pipeline pressure to the pre-charge pressure value. Simultaneously, a pre-adjustment command is sent to the motor regenerative braking subsystem to adjust the preset value of the regenerative braking intensity: ； This allows the motor to enter the power generation preparation state in advance.
7. The adaptive braking system for a hilly tractor according to claim 2, characterized in that: In the emergency braking mode, when the brake pedal opening is... When a collision risk exists, the central domain controller determines the target deceleration. ,in The road surface adhesion coefficient is used; a neural network PID controller calculates the front and rear axle braking force distribution based on vehicle speed, target deceleration, and road surface type, and sends a full braking command to the electro-hydraulic braking subsystem; at the same time, the slip ratio of each wheel is monitored in real time. ,when Exceeding the seizure threshold Anti-lock braking system is achieved in real time.
8. The adaptive braking system for a hilly mountain tractor according to claim 1, characterized in that: The electro-hydraulic braking subsystem includes an electro-hydraulic proportional valve and a wheel-side wet brake. The electro-hydraulic proportional valve adopts an integrated structure in which the pilot valve core is nested inside the main valve core. The bottom of the main valve core is provided with an annular buffer head and a rectangular groove, and the barrel wall has a V-shaped groove for adjusting the input current. Proportionally control braking pressure ,satisfy ,in This is the proportionality coefficient.
9. The adaptive braking system for a hilly tractor according to claim 1, characterized in that: The active attitude adjustment mechanism includes a servo electric cylinder with linear displacement. With motor rotation angle satisfy ,in The lead of the lead screw; the servo electric cylinder is controlled by a servo driver employing a three-closed-loop control structure and an adaptive sliding mode control algorithm, with position tracking error... Satisfying the sliding mode reaching law ,in For sliding surface, and For adaptive adjustment parameters.
10. The adaptive braking system for a hilly tractor according to claim 1, characterized in that: The central domain controller is also configured to perform smooth mode switching control, limiting the rate of change of control inputs when switching between different braking modes to ensure the rate of change of braking force. Suspension adjustment rate Motor torque change rate .