Steering failure emergency driving method for four-wheel full-vector aircraft tractor

Abstract

The invention belongs to the technical field of civil aviation special vehicles, and particularly introduces a three-wheel failure emergency driving method suitable for four-wheel independent driving and steering of a civil aircraft tractor. The method comprises the following emergency driving modes: 1, a four-wheel independent steering method; 2, a single-wheel driving steering method; and 3, a wheel braking method. The four-wheel independent steering method is used for independently controlling the internal and external corner relation between wheels. The single-wheel driving steering method is used for resolving the turning angles of four wheels; the wheel braking method is used for limiting the wheel braking force. In a traditional vehicle, after three wheels fail, the vehicle cannot run, the whole vehicle generates yawing moment deviation, and the rear two wheels cannot steer, so that the vehicle cannot advance. However, on a full-vector automobile, when the automobile runs straight, the steering directions of the other three wheels can be kept horizontal by enabling the working driving wheels to penetrate through the center of the automobile, so that the yawing moment is eliminated, and stable straight running is achieved.

Description

Technical Field

[0001] This innovation belongs to the field of civil aviation special vehicle technology, especially the emergency driving method of civil aircraft tractor Background Art

[0002] Aircraft tractors are a type of support equipment used to tow aircraft on the ground at airports. When an aircraft is being manufactured, repaired, or its engine is shut down, the movement of the aircraft requires special towing equipment. With the development of towing technology, full-vector civilian tractors have been developed. However, when three wheels of a traditional tractor fail to turn, the vehicle will be unable to move forward and will generate a yaw moment deviation. In particular, when the remaining wheel cannot turn, the control difficulty is further increased, posing a safety risk. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a three-wheel failure emergency driving method for a four-wheel full-vector aircraft tractor, so that when three wheels fail to turn, the tractor can still achieve smooth and straight driving, ensuring the safety of aircraft ground traction operations. The method includes the following three emergency driving modes:

[0004] 1. Four-wheel independent steering method: This method allows independent control of the inner and outer turning angle relationship between the wheels. In emergency driving situations, the system will control the steering angle of each wheel through electric hydraulics or electric motors to achieve precise control of the tractor and avoid driving deviation caused by three-wheel steering failure. When one or two of the three wheels fail to turn, the system will promptly adjust the steering angle of the other wheels to ensure that the vehicle moves in the expected direction.

[0005] 2. Three-drive steering method: This method aims to solve the steering problem of the four wheels of the tractor. When the steering of three wheels fails, the steering control can still be achieved by driving the remaining wheel. The system will monitor the steering state and vehicle speed of the wheel in real time, and adjust the speed and steering angle of the wheel through intelligent control algorithms, so that the tractor can steer steadily and avoid loss of control.

[0006] Under the operation of the ROS-based route planning system, the towbarless tractor can reach the correct docking position, and the AI ​​machine vision posture solving system directs the towbarless tractor to complete precise docking and hold tightly;

[0007] 3. Wheel braking method: This method is used to limit the braking force of the wheels, especially the wheels with three wheel steering failures. When the system detects that the three wheel steering failures have occurred, the braking force distribution of these wheels will be controlled through solenoid valves or electronically controlled hydraulic valves to prevent them from generating excessive resistance and interference, thereby maintaining the stability and balance of the tractor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram of the four-wheel independent steering of the present invention;

[0009] Figure 2 This is a schematic diagram of the single-wheel drive straight-line driving of the present invention;

[0010] Figure 3 This is a schematic diagram of the single-wheel drive steering of the present invention;

[0011] Figure 4 It is a schematic diagram of wheel braking of the present invention. DETAILED DESCRIPTION

[0012] In the implementation of this patent, the emergency driving method for steering failure of a four-wheel full-vector aircraft tractor can be implemented by the following specific steps:

[0013] In the emergency driving method of steering failure of a four-wheel full-vector aircraft tractor, we can introduce the following specific formula to achieve four-wheel independent steering, three-drive steering and wheel braking:

[0010] 1. Four-wheel independent steering method: In this method, we use a formula to calculate the steering angle of each wheel and control its independent steering. Assume that θ_i represents the steering angle of the i-th wheel (i=1, 2, 3, 4), where θ_1 represents the front left wheel, θ_2 represents the front right wheel, θ_3 represents the rear left wheel, and θ_4 represents the rear right wheel. Assume that Δθ_i represents the change in the steering angle of the wheel, then the steering angle calculation formula for each wheel is as follows:

[0014] θ_1=θ_1+Δθ_1

[0015] θ_2=θ_2+Δθ_2

[0016] θ_3=θ_3+Δθ_3

[0017] θ_4=θ_4+Δθ_4

[0018] V=V+ΔV

[0019] θ=θ+Δθ

[0020] 3. Wheel braking method: In this method, we use a formula to control the braking force distribution of the steering failure wheel. Assume that F_1, F_2, F_3, and F_4 represent the braking forces corresponding to wheel 1, wheel 2, wheel 3, and wheel 4 respectively. Assume that F_max represents the maximum braking force, which can be set according to the vehicle performance. The wheel braking force distribution calculation formula is as follows:

[0021] F_1=F_1 / F_max

[0022] F_2=F_2 / F_max

[0023] F_3=F_3 / F_max

[0024] F_4=F_4 / F_max

[0025] In the event of wheel steering failure, we can set F_1, F_2, and F_3 to 0 and F_4 to 1, so that the remaining wheel can bear all the braking force and maintain the stability and balance of the tractor.

Claims

1. A four-wheel full vector aircraft tractor steering failure emergency driving method, characterized in that This method is applicable to civil aircraft tractors that use a four-wheel independent drive and steering system and includes the following emergency driving methods: a) Four-wheel independent steering method, used to independently control the inner and outer turning angle relationship between the wheels; b) Three-drive steering method, used to achieve steering control by driving the remaining one wheel when three wheels fail to turn; c) Wheel braking method, which is used to limit the braking force on the wheel with steering failure and maintain the stability and balance of the tractor.

2. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The four-wheel independent steering method includes steps to control the steering angle of the wheels through electro-hydraulic or electric motors to ensure that the tractor moves in the intended direction in the event of steering failure.

3. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The three-drive steering method includes the steps of adjusting the rotation speed and steering angle of the remaining wheel through an intelligent control algorithm to achieve robust steering control of the tractor in the event of three wheel steering failures.

4. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The wheel braking method includes the steps of controlling the braking force distribution of the steering failure wheel through a solenoid valve or an electronically controlled hydraulic valve to prevent the steering failure wheel from generating excessive resistance and interference and maintain the stability and balance of the tractor.

5. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The conversion of the emergency driving mode is a step of automatically exiting the emergency driving mode when the system detects that the steering state of the vehicle returns to normal.

6. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The steering state of a vehicle includes key parameters such as the vehicle's steering angle, vehicle speed, and wheel rotation.

7. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The distribution of wheel braking force is adjusted according to the maximum braking force F_max set according to vehicle performance, limiting the braking force distribution of the steering failure wheel.

8. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The calculation formulas for the steering angle and vehicle speed of the remaining wheel in the three-drive steering method are: V=V+ΔV θ=θ+Δθ。 9. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The calculation formula for the wheel braking force distribution in the wheel braking method is: F_1=F_1 / F_max F_2=F_2 / F_max F_3=F_3 / F_max F_4=F_4 / F_max.

10. The steering failure emergency driving method of a four-wheel full-vector aircraft tractor according to claim 1, wherein: The specific control algorithms and parameter settings of the four-wheel independent steering method, three-drive steering method and wheel braking method are planned and adjusted in detail according to vehicle performance and application requirements.

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