A heavy-duty vehicle distributed steering structure and control method

Abstract

The present application relates to heavy vehicle automatic driving intelligent chassis steer-by-wire technology field, specifically relates to a kind of heavy vehicle distributed steering structure and control method, including frame, steering transmission part and steering assist part, steering transmission part includes steering gear bracket, steering gear, steering rocker and steering drag link, a set of steering rocker, steering drag link is installed on each electric control hydraulic power steering gear, and steering force is transmitted to left and right electric wheel, and drive wheel steering;Steering assist part includes steering oil tank, electric steering oil pump motor, steering oil pump, steering oil pipe, each steering oil pump provides assist force to two electric control hydraulic power steering gears respectively through steering pipeline, and two steering oil tanks are respectively provided and store hydraulic oil for two electric control hydraulic power steering gears and steering oil pump;The present application is helpful to realize independent control, can achieve the most ideal left and right wheel angle relationship, reduce tire wear.In addition, the embodiment of the present application can be used for independent suspension wheel steering control.

Description

Technical Field

[0001] This invention relates to the field of intelligent chassis steer-by-wire technology for autonomous driving of heavy vehicles, specifically to a distributed steering structure and control method for heavy vehicles. Background Technology

[0002] like Figure 1 As shown, the current multi-wheel steering system of heavy commercial vehicles is an integral axle. The steering knuckle arms of the left and right axles are connected in the middle by a steering tie rod. There are two hydraulic cylinders on each side. The fixed end is connected to the central axle, and the moving end is connected to the steering knuckle arm. The extension and retraction of the hydraulic cylinders are controlled by an electro-hydraulic proportional valve group, thereby controlling the steering angle of the left and right wheels.

[0003] Existing steering systems cannot independently control the wheels on both sides, failing to achieve the optimal left and right wheel angles. Furthermore, they cannot be used for steering control of independent suspension wheels. Therefore, a distributed steering structure and control method for heavy-duty vehicles needs to be designed to address the problems of the inability to independently control the wheels on both sides and achieve the optimal left and right wheel angles in existing heavy-duty commercial vehicles. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a distributed steering structure and control method for heavy vehicles.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a distributed steering structure for heavy vehicles, including a frame, a steering transmission part and a steering assist part, wherein the steering transmission part includes a steering gear bracket, a steering gear, a steering rocker arm and a steering tie rod, the steering gear bracket is mounted on the frame, two steering gears are provided and are respectively mounted on both sides of the steering gear bracket, the steering rocker arm is respectively mounted on the steering gear, the steering rocker arm is connected to the steering tie rod, the steering tie rod is connected to the steering knuckle arm of the steering wheel, and the steering rocker arm and the steering tie rod transmit steering force;

[0006] The power steering system includes a power steering reservoir, an electric power steering pump motor, power steering pumps, and power steering hoses. The electric power steering pump motor drives two power steering pumps, each of which is equipped with a power steering reservoir and power steering hoses. The power steering reservoir provides power steering assistance to the two steering gears through each power steering pump.

[0007] Preferably, the steering rocker arm is rotatably connected to one end of the steering tie rod via a pin, and the other end of the steering tie rod is rotatably connected to the steering wheel knuckle arm via a pin.

[0008] Preferably, the steering wheel steering knuckle arm is mounted on the axle, and the axle is mounted on the vehicle frame.

[0009] Preferably, the steering gear is an electro-hydraulic power steering system.

[0010] Preferably, the inlet of the steering pump is connected to the steering oil tank via a steering oil pipe, the outlet of the steering pump is connected to the steering gear via a steering oil pipe, and the steering gear is connected to the vehicle controller.

[0011] A control method for a distributed steering structure of a heavy-duty vehicle includes the following steps:

[0012] S1. The autonomous driving controller sends a steering axis equivalent angle request to the vehicle controller;

[0013] S2. The vehicle controller converts the steering shaft equivalent angle request into a steering angle request for the electro-hydraulic power steering system of the left and right wheels, and sends it to the electro-hydraulic power steering system of the left and right wheels.

[0014] S3: The electro-hydraulic power steering systems of the left and right wheels execute steering angle requests and return the executed steering angle.

[0015] S4. The vehicle controller receives the steering angle of the electro-hydraulic power steering system, calculates the equivalent steering angle of the steering shaft, and returns it to the automatic driving controller.

[0016] Preferably, in step S2, when the vehicle controller receives the steering shaft equivalent angle request, it first limits the input steering shaft equivalent angle through the limiting module, then calculates the target steering angle of the left wheel based on the steering shaft equivalent angle request, and then obtains the target steering angle of the left steering gear through the lookup table module, and outputs it to the rate of change limiting module. The limit value of the rate of change limiting module is based on the vehicle speed. Through the lookup table module, the maximum limit value of the steering angle at different vehicle speeds is calculated, and finally the target steering angle of the left steering gear is obtained.

[0017] Preferably, in step S2, the vehicle controller receives the feedback angle from the left steering gear, obtains the actual turning angle of the left wheel through the lookup table module, calculates the equivalent wheel turning angle at the actual steering axis and the target turning angle of the right wheel, and outputs the target turning angle of the right wheel through the lookup table module to determine the target steering angle of the right steering gear.

[0018] Preferably, in step S4, the vehicle controller receives the feedback angle from the left electro-hydraulic power steering unit, obtains the actual turning angle of the left wheel through the lookup table module, and calculates the equivalent wheel turning angle at the actual steering axle.

[0019] The present invention has the following beneficial effects:

[0020] This invention discloses a distributed steering structure and control method for heavy-duty vehicles. The steering system includes two sets of electro-hydraulic power steering units, steering tie rods, and steering rocker arms, controlling the steering angles of the left and right wheels separately, and providing a steering control method. The steering system includes a steering assist module, consisting of an electric steering pump motor driving two steering pumps, each equipped with a steering oil tank and oil pipes, providing assistance to the left and right electro-hydraulic power steering units. Angle sensors integrated on the electro-hydraulic power steering units are used to calculate and provide feedback on the wheel steering angles, eliminating the need for additional angle sensors at the steering wheel kingpin. The equivalent axle angle is converted into steering angles for the two electro-hydraulic power steering units, achieving wheel steering angle control. This facilitates independent control, achieving the most ideal left and right wheel steering angle relationship and reducing tire wear. Furthermore, embodiments of this invention can be used for independent suspension wheel steering control. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an existing multi-wheel steering system for heavy commercial vehicles.

[0022] Figure 2 This is a schematic diagram of a distributed steering structure for heavy-duty vehicles.

[0023] Figure 3 This is a flowchart of the control method for the distributed steering structure of heavy vehicles.

[0024] Figure 4 This is a schematic diagram illustrating the principle of calculating the steering angle of a distributed steering structure in heavy-duty vehicles.

[0025] Figure 5 This is a schematic diagram of the principle of the calculation method for the equivalent axle rotation angle of steering feedback in the distributed steering structure of heavy vehicles.

[0026] In the diagram: 1-Steering controller; 2-Original axle; 3-Original frame; 4-Hydraulic power steering cylinder; 41-Hydraulic power steering cylinder A; 42-Hydraulic power steering cylinder B; 43-Hydraulic power steering cylinder C; 44-Hydraulic power steering cylinder D; 5-Oil cooler; 6-Electro-hydraulic proportional valve assembly; 7-Steering oil reservoir; 8-Electro-hydraulic pump; 9-Transmission mechanism; 10-Steering angle sensor;

[0027] 100 - Chassis; 200 - Axle; 300 - Steering wheel / steering knuckle arm; 400 - Vehicle controller; 501 - Steering gear; 502 - Steering gear bracket; 503 - Steering rocker arm; 504 - Steering tie rod; 601 - Steering fluid reservoir; 602 - Electric steering fluid pump motor; 603 - Steering fluid pump; 604 - Steering fluid hose. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Definitions of abbreviations and key terms:

[0030] Electro-hydraulic power steering: integrates a recirculating ball steering gear, motor, controller, and steering angle sensor to execute the vehicle's steering angle request, amplify the steering torque to drive the wheels to turn, and provide feedback signals such as steering angle and steering torque.

[0031] like Figure 2 As shown, a distributed steering structure for heavy vehicles includes a frame 100, a steering transmission part, and a steering assist part. The steering transmission part includes a steering gear bracket 502, a steering gear 501, a steering rocker arm 503, and a steering tie rod 504. The steering gear bracket 502 is mounted on the frame 100. Two steering gears 501 are provided and are respectively mounted on both sides of the steering gear bracket 502. The steering rocker arms 503 are respectively mounted on the steering gears 501. The steering rocker arms 503 are connected to the steering tie rods 504. The steering tie rods 504 are connected to the steering knuckle arm 300 of the steering wheel. The steering rocker arms 503 and the steering tie rods 504 transmit steering force.

[0032] The steering rocker arm 503 is rotatably connected to one end of the steering tie rod 504 via a pin, and the other end of the steering tie rod 504 is rotatably connected to the steering wheel knuckle arm 300 via a pin. The steering wheel knuckle arm 300 is mounted on the axle 200, and the axle 200 is mounted on the frame 100.

[0033] Steering gear 501 is an electro-hydraulic power steering gear.

[0034] The power steering system includes a power steering reservoir 601, an electric power steering pump motor 602, a power steering pump 603, and a power steering hose 604. The electric power steering pump motor 602 drives two power steering pumps 603. Each power steering pump 603 is equipped with a power steering reservoir 601 and a power steering hose 604. The power steering reservoir 601 provides power steering assistance to the two steering gears 501 through each power steering pump 603.

[0035] The inlet of the steering pump 603 is connected to the steering oil tank 601 via the steering oil pipe 604, and the outlet of the steering pump 603 is connected to the steering gear 501 via the steering oil pipe 604. The steering gear 501 is connected to the vehicle controller 400.

[0036] like Figure 2 As shown, a control method for a distributed steering structure of a heavy-duty vehicle includes the following steps:

[0037] Step 101: The autonomous driving controller sends a steering axis equivalent angle request to the vehicle controller 400.

[0038] Step 102: The vehicle controller 400 converts the equivalent steering angle request of the steering shaft into the steering angle request of the electro-hydraulic power steering system of the left and right wheels, and sends it to the electro-hydraulic power steering system of the left and right wheels.

[0039] like Figure 4 As shown, when the vehicle controller 400 receives the steering shaft equivalent angle request, it first limits the input steering shaft equivalent angle through the limiting module. Then, it calculates the target steering angle of the left wheel based on the steering shaft equivalent angle request. Next, it obtains the target steering angle of the left steering gear through the lookup table module and outputs it to the rate of change limiting module. The limit value of the rate of change limiting module is based on the vehicle speed. Through the lookup table module, it calculates the maximum limit value of the steering angle at different vehicle speeds and finally obtains the target steering angle of the left steering gear.

[0040] The vehicle controller 400 receives the feedback angle from the left steering gear 501, obtains the actual turning angle of the left wheel through the lookup table module, calculates the equivalent wheel turning angle at the actual steering shaft and the target turning angle of the right wheel, and outputs the target turning angle of the right wheel through the lookup table module to determine the target steering angle of the right steering gear.

[0041] Step 103: The electro-hydraulic power steering systems of the left and right wheels execute the steering angle request and return the executed steering angle.

[0042] Step 104: The vehicle controller 400 receives the steering angle of the electro-hydraulic power steering system, calculates the equivalent steering angle of the steering shaft, and returns it to the automatic driving controller.

[0043] like Figure 5 As shown, the vehicle controller 400 receives the feedback angle from the left electro-hydraulic power steering system, obtains the actual turning angle of the left wheel through the lookup table module, and calculates the equivalent wheel turning angle at the actual steering shaft.

[0044] Two steering pumps 603 are mounted on the electric power steering pump motor 602. Each steering pump 603 provides power to the two electro-hydraulic power steering units through a steering oil pipe 604. Two steering oil tanks 601 supply and store hydraulic oil for the two electro-hydraulic power steering units and the steering pumps 603, respectively.

[0045] A distributed steering control method receives a request for the equivalent steering axis angle, converts it into steering angles for two electro-hydraulic power steering systems, and executes the steering angles. Simultaneously, based on the steering angle feedback from the electro-hydraulic power steering systems, the equivalent axle angle is calculated and fed back to the autonomous driving system. This facilitates independent control, achieves the optimal left and right wheel steering angle relationship, and reduces tire wear.

[0046] This invention is not limited to the above-described embodiments. Anyone should know that any structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention.

[0047] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A distributed steering structure for heavy-duty vehicles, characterized in that, The vehicle includes a frame, a steering transmission system, and a steering assist system. The steering transmission system includes a steering gear bracket, a steering gear, a steering rocker arm, and a steering tie rod. The steering gear bracket is mounted on the frame. There are two steering gears, which are respectively mounted on both sides of the steering gear bracket. Steering rocker arms are respectively mounted on the steering gears. The steering rocker arms are connected to the steering tie rods. The steering tie rods are connected to the steering knuckle arms of the steering wheels. The steering rocker arms and steering tie rods transmit steering force. The power steering system includes a power steering reservoir, an electric power steering pump motor, power steering pumps, and power steering hoses. The electric power steering pump motor drives two power steering pumps, each of which is equipped with a power steering reservoir and power steering hoses. The power steering reservoir provides power steering assistance to the two steering gears through each power steering pump.

2. The heavy-duty vehicle distributed steering structure according to claim 1, characterized in that, The steering rocker arm is rotatably connected to one end of the steering tie rod via a pin, and the other end of the steering tie rod is rotatably connected to the steering wheel knuckle arm via a pin.

3. The heavy-duty vehicle distributed steering structure according to claim 2, characterized in that, The steering wheel steering knuckle arm is mounted on the axle, and the axle is mounted on the vehicle frame.

4. The heavy-duty vehicle distributed steering structure according to claim 1, characterized in that, The steering system is an electro-hydraulic power steering system.

5. The heavy-duty vehicle distributed steering structure according to claim 1, characterized in that, The inlet of the steering pump is connected to the steering oil tank via a steering oil pipe, and the outlet of the steering pump is connected to the steering gear via a steering oil pipe. The steering gear is connected to the vehicle controller.

6. The control method for the distributed steering structure of heavy-duty vehicles according to any one of claims 1-5, characterized in that, Includes the following steps: S1. The autonomous driving controller sends a steering axis equivalent angle request to the vehicle controller; S2. The vehicle controller converts the steering shaft equivalent angle request into a steering angle request for the electro-hydraulic power steering system of the left and right wheels, and sends it to the electro-hydraulic power steering system of the left and right wheels. S3: The electro-hydraulic power steering systems of the left and right wheels execute steering angle requests and return the executed steering angle. S4. The vehicle controller receives the steering angle of the electro-hydraulic power steering system, calculates the equivalent steering angle of the steering shaft, and returns it to the automatic driving controller.

7. The control method for the distributed steering structure of heavy-duty vehicles according to claim 6, characterized in that, In step S2, the vehicle controller receives the steering shaft equivalent angle request. First, it limits the input steering shaft equivalent angle through the limiting module. Then, it calculates the target steering angle of the left wheel based on the steering shaft equivalent angle request. Next, it obtains the target steering angle of the left steering gear through the lookup table module and outputs it to the rate of change limiting module. The limit value of the rate of change limiting module is based on the vehicle speed. Through the lookup table module, it calculates the maximum limit value of the steering angle at different vehicle speeds and finally obtains the target steering angle of the left steering gear.

8. The control method for the distributed steering structure of heavy-duty vehicles according to claim 7, characterized in that, In step S2, the vehicle controller receives the feedback angle from the left steering gear, obtains the actual turning angle of the left wheel through the lookup table module, calculates the equivalent wheel turning angle at the actual steering shaft and the target turning angle of the right wheel, and outputs the target turning angle of the right wheel through the lookup table module to determine the target steering angle of the right steering gear.

9. The control method for the distributed steering structure of heavy-duty vehicles according to claim 6, characterized in that, In step S4, the vehicle controller receives the feedback angle from the left electro-hydraulic power steering unit, obtains the actual turning angle of the left wheel through the lookup table module, and calculates the equivalent wheel turning angle at the actual steering shaft.

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