Full-vector control chassis structure of high-speed heavy-load tractor

Abstract

The invention provides a full-vector control chassis structure, and relates to the technical field of active safety of tractors, the full-vector control chassis structure comprises a full-vector drive-by-wire chassis domain controller and electric wheel control units, and each wheel corresponds to one electric wheel control unit. Each electric wheel control unit comprises a driving control unit, a braking control unit, a steering control unit and a suspension adjusting unit; the full-vector drive-by-wire chassis domain controller controls two clutches connected with front wheels to be closed so that the front wheels can move in a centralized mode. And the full-vector drive-by-wire chassis domain controller controls each electric control unit to carry out driving control, braking control, steering control and suspension adjustment on the corresponding wheels.

Description

Technical Field

[0001] The invention relates to the technical field of full-vector automobiles, and in particular to a high-speed and heavy-load full-vector control chassis structure. Background Art

[0002] The high-speed heavy-load full-vector tractor chassis structure is a special chassis design for high-speed transportation and heavy-load tasks. The full-vector traction technology can provide excellent handling performance and traction under different road conditions and load conditions. Full-vector traction technology refers to the more precise distribution of traction by controlling the torque output of each wheel of the vehicle separately. By adjusting the speed and torque output of each wheel, the driving state of the vehicle can be changed, and the handling performance and stability can be improved. In order to adapt to high-speed driving, the chassis needs to have good rigidity and stability to ensure that the vehicle will not produce excessive vibration and risk of loss of control at high speed. The chassis structure needs to be able to withstand large loads and remain stable and reliable during long-term use. Summary of the invention

[0003] The purpose of the present invention is to provide a full vector control chassis structure for a high-speed heavy-load tractor, expand the controllable range of vehicle dynamics, reduce the mutual constraints between multiple performance indicators of the vehicle, increase the theoretical upper limit of multi-objective optimization, improve road adaptability, and when a fault occurs, compared with other vehicle control methods, have more braking and steering options and can still work normally, with higher inherent safety.

[0004] The ROS-based route planning system is based on the ROS operating system, an odometer, a nine-axis IMU, a laser radar, and preferably a depth camera;

[0005] In a first aspect, an embodiment of the present invention provides a full vector control chassis structure, including: a full vector wire control chassis domain controller and an electric wheel control unit, each wheel corresponds to one electric wheel control unit, each electric wheel control unit includes a drive control unit, a brake control unit, a steering control unit and a suspension adjustment unit;

[0005] The full-vector drive-by-wire chassis domain controller controls each of the electric control units to perform drive control, braking control, steering control and suspension adjustment on the corresponding wheels.

[0006] In an optional embodiment, the full vector wire-controlled chassis domain controller controls two clutches connected to the front wheels to open, so as to enable the front wheels to be distributedly driven;

[0007] or,

[0008] The full-vector wire-controlled chassis domain controller controls the closure of two clutches connected to the front wheels to enable centralized drive of the front wheels.

[0009] In an optional embodiment, the step of controlling the corresponding actuator to perform three-dimensional force control operations on each wheel in the lateral, longitudinal and vertical directions based on the control instruction includes:

[0010] The driving torque of the wheel is controlled by the wheel hub motor, and the braking torque of the wheel is controlled by the motor and the hydraulic brake-by-wire system to control the longitudinal force; The drawings required for the description of the method or prior art are briefly introduced. Obviously, the drawings in the following description are

[0011] A steer-by-wire system using a motor and a reducer controls the turning angle of the wheel to control the lateral force;

[0012] The magnetorheological active suspension is used to control the damping of the wheels and the vehicle body to control the vertical force. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the basic architecture of a full vector controlled wire-controlled chassis for a high-speed heavy-load tractor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention.

[0015] Figure 1 A schematic diagram of the basic architecture of a full vector control wire-controlled chassis for an automobile provided by an embodiment of the present invention;

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The current under-actuated system has great difficulty in dynamic control and is prone to instability, which is not conducive to the driving control of the vehicle.

[0018] Based on this, an embodiment of the present invention provides a full vector control chassis structure for a high-speed heavy-load tractor, which expands the controllable range of vehicle dynamics, reduces the mutual constraints between multiple performance indicators of the vehicle, and improves the theoretical upper limit of multi-objective optimization.

[0019] To facilitate understanding of this embodiment, a high-speed heavy-load tractor full vector control chassis structure disclosed in an embodiment of the present invention is first introduced in detail.

[0020] Reference Figure 1 , an embodiment of the present invention provides a full vector control chassis structure for a high-speed heavy-load tractor, including: a full vector wire-controlled chassis domain controller and an electric wheel control unit, each wheel corresponds to one electric wheel control unit, each electric wheel control unit includes a drive control unit, a brake control unit, a steering control unit and a suspension adjustment unit;

[0021] The full-vector drive-by-wire chassis domain controller controls each of the electric control units to perform drive control, braking control, steering control and suspension adjustment on the corresponding wheels.

[0022] Here, a typical overdrive system of a full vector control (FVC) vehicle is proposed: each wheel has four independent control components: drive, brake, steering and suspension. For common four-wheel vehicle systems, there are 16 controllable inputs, covering the maximum independent input set of the vehicle, that is, the regulation of 12 independent wheel forces can be achieved. After the FVC vehicle increases the controllable input, on the one hand, it can expand the controllable range of vehicle dynamics, reduce the mutual constraints between multiple performance indicators of the vehicle, and improve the theoretical upper limit of multi-objective optimization; on the other hand, a cross-redundant complementary mechanism can be formed between the actuators of various functions to ensure the safety of the vehicle under various component failure conditions. The inherent safety of the vehicle itself is the most important foundation for future advanced intelligent vehicles.

[0023] In an optional embodiment, the full vector wire-controlled chassis domain controller controls two clutches connected to the front wheels to open, so as to enable the front wheels to be distributedly driven;

[0024] or,

[0025] The full-vector wire-controlled chassis domain controller controls the closure of two clutches connected to the front wheels to enable centralized drive of the front wheels.

[0026] As an optional embodiment, the four wheels need to be designed as electric wheels that can independently drive, brake, steer and adjust the suspension, and have independent electronic control systems. The FVC chassis domain controller is designed as the main control module of the entire chassis, responsible for the dynamic control of the entire vehicle and the dynamic coordination of the four electric wheels. The two front wheels are designed to be able to switch between distributed drive and centralized drive through a clutch.

[0027] Here, a full vector control chassis structure is adopted, and based on automotive electronic control technology, the optimal implementation form and control method of the three-dimensional force of the wheel are designed. Among them, the comparison of the functions and implementation methods of the FVC chassis and the conventional wire-controlled chassis currently used in smart cars is shown in Table 1.

[0028] Table 1. Function comparison between FVC chassis and conventional drive-by-wire chassis

[0029] Component Function Conventional Wire Drive Chassis FVC chassis drive Drive torque of front axle / rear axle Driving torque of a single wheel brake Vehicle deceleration Brake fluid pressure of a single wheel Steering Front wheel steering angle Steering angle of a single wheel Suspension Passive suspension, uncontrollable Damping or displacement of a single wheel and vehicle body Controllable input 3-7 16

[0030] As can be seen in Table 1, the control of driving, braking, steering and suspension of conventional vehicles is an under-driven system with less controllable input. The driving controls the driving torque of the front axle / rear axle; the braking controls the deceleration of the whole vehicle; the steering controls the front wheel angle; and the passive suspension is uncontrollable.

[0031] For the FVC vehicle chassis, the overdrive system, each wheel is an independent module, including drive, braking, steering and active suspension. The vehicle chassis has 16 inputs, which can realize the regulation of 12 forces on 4 wheels and 4 displacements or damping of four independent suspensions.

[0032] After the FVC car increases the controllable input, on the one hand, it can expand the controllable range of the vehicle's dynamics, reduce the mutual constraints between multiple performance indicators of the vehicle, improve the theoretical upper limit of multi-objective optimization, realize different driving modes under different working conditions, and have good adaptability of the vehicle; on the other hand, a cross-redundant complementary mechanism can be formed between the actuators of various functions to ensure the safety of the vehicle under various component failure conditions.

[0033] In an optional embodiment, in the event of a failure of one type of actuator on the FVC chassis, the coordination between the four wheels and the complementarity between different actuators can ensure that the braking and steering functions will not fail completely. This inherent safety mechanism can achieve a higher fault tolerance rate for the vehicle and ensure that the vehicle can still achieve normal driving functions when some components fail.

Claims

1. A high-speed heavy-load tractor full vector control chassis structure, characterized in that: Based on the full vector control chassis structure, the structure includes: a full vector wire-controlled chassis domain controller and an electric wheel control unit, each wheel corresponds to an electric wheel control unit, and each electric wheel control unit includes a drive control unit, a braking control unit, a steering control unit and a suspension adjustment unit.

2. According to claim 1, a high-speed heavy-load tractor full vector control chassis structure is characterized in that: The full-vector by-wire chassis domain controller controls each of the electric wheel control units to perform drive control, brake control, steering control and suspension adjustment on the corresponding wheels; the full-vector by-wire chassis domain controller controls the two clutches connected to the front wheels to open, so that the front wheels are distributedly driven; Alternatively, the full-vector wire-controlled chassis domain controller controls the closure of two clutches connected to the front wheels to enable the front wheels to be centrally driven; the method includes: obtaining road traffic environment information and driver control instructions to determine the current driving condition; determining a control mode according to the current driving condition, and determining a control instruction for each wheel based on each of the control modes and the current driving condition; the step of determining a control instruction for each of the wheels based on each of the control modes and the current driving condition includes: allocating torque to a corresponding number of the wheels according to a straight-line driving condition to brake or drive the wheels, the straight-line driving condition including normal straight-line driving and abnormal straight-line driving; controlling the rear wheels and the front wheels to take any angle of steering, take any angle of steering, take any angle of steering according to the steering condition The same-phase steering method is used for high-speed lane changing, and the reverse-phase steering method is used for low-speed turning; the body is controlled to generate anti-roll torque and suspension adjustment according to the obstacle avoidance situation; among them, when the driver's steering wheel has no significant steering angle input and the roughness of the left and right roads is judged to be almost the same, the straight-line driving mode is adopted to control the input of the hub motors of the four wheels; if it is normal straight-line driving, the tractor will distribute the torque between the front and rear axles and then distribute the torque of the rear wheels evenly to the left and right hub motors; if it is abnormal straight-line driving, when the two sides of the road where the car is driving are unevenly dry and wet, the motor controller will adjust the size of its output torque; when the steering wheel has significant steering angle input and the roughness of the left and right roads is judged to be almost the same, the steering mode is adopted, and the specific steering mode is determined according to the vehicle speed and driving intention.

3. According to claim 2, a high-speed heavy-load tractor full vector control chassis structure is characterized in that: The steps of controlling the corresponding actuators to perform three-dimensional force control operations on each wheel in the lateral, longitudinal and vertical directions based on the control instructions include: controlling the driving torque of the wheel by the wheel hub motor, controlling the braking torque of the wheel by the motor and hydraulic brake-by-wire system, and controlling the longitudinal force; controlling the steering angle of the wheel by the motor and reducer by the steering-by-wire system, and controlling the lateral force; and controlling the damping of the wheel and the vehicle body by the magnetorheological active suspension, and controlling the vertical force.

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