Agricultural Vehicle Steering Actuator Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Agricultural vehicles face challenges in minimizing steering radius while reducing energy dissipation and soil damage due to tire slippage, especially when operating in four-wheel drive mode, which affects the soil surface and efficiency.
Innovation Solution
The vehicle employs a control unit to actively adjust the vertical position of front wheels during steering using actuators, allowing the inner front wheel to lift off the ground, reducing vertical pressure and energy dissipation, and independently controlling the rotation speed of wheels to maintain optimal steering kinematics, effectively behaving like a three-wheeled vehicle during tight turns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the steering radius is reduced to optimize vehicle paths and reduce work times, then productivity is improved, but tire slippage increases causing energy dissipation and soil damage
Solution Approach 1:
The patent applies dynamics by making the front wheel configuration changeable during operation. The system dynamically switches between two-wheel drive and four-wheel drive modes based on steering conditions. During tight steering maneuvers, the inner front wheel is disconnected from the drive train, allowing the vehicle to operate in a configuration that minimizes slippage while maintaining the ability to engage four-wheel drive when needed for traction.
Solution Approach 2:
The patent changes the operational parameters of the drive system by selectively engaging or disengaging the inner front wheel from the drive train during steering maneuvers. This parameter change allows the system to adapt to different steering radii, reducing tire slippage and energy dissipation when executing tight turns while maintaining four-wheel drive capability when traction is needed.
2Reliability
If four-wheel drive mode is engaged to improve traction, then reliability is improved, but tire slippage and energy dissipation worsen during steering
Solution Approach 1:
The system dynamically adjusts the drive configuration by disconnecting the inner front wheel during steering maneuvers. This dynamic change allows the vehicle to maintain four-wheel drive capability when traction is needed while avoiding the energy dissipation that would occur if all four wheels remained engaged during tight turns.
Solution Approach 2:
The operational parameter of the drive train is changed by selectively engaging or disengaging the inner front wheel. This parameter change optimizes the balance between maintaining reliable traction through four-wheel drive and minimizing energy dissipation during steering by reducing the number of driven wheels when appropriate.
3Device complexity
If conventional transmission with fixed gear ratios is used, then device complexity is reduced, but steering performance and energy efficiency worsen during low radius turns
Solution Approach 1:
The drive train is segmented into independent controllable units, with the inner front wheel being selectively disconnectable from the drive train. This segmentation allows the system to isolate the inner wheel during steering maneuvers, preventing it from contributing to energy dissipation while maintaining the simplicity of conventional transmission components for the remaining driven wheels.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A vehicle (1), in particular an agricultural vehicle, has a chassis (3) supporting a front axle (7), which is provided with two steerable front wheels (9), and with an independent front suspension (20) for each of the front wheels (9); during a steering manoeuvre, the front wheels defining an inner front wheel (9a) and an outer front wheel (9b), respectively nearer and farther with respect to a steering center (C); the chassis (3) supports a rear axle (8), having two rear wheels (10), and a powertrain arranged to drive at least part of the front and rear wheels (9,10); the front axle (7) has, for each of the front wheels (9), a respective actuator (25), operable to raise and lower the corresponding front wheel (9) with respect to the chassis (3); a control unit (26) is provided to handle the steering manoeuvre by operating at least one of these actuators (25) in response to a steering signal so as to reduce vertical pressure between the inner front wheel (9a) and the ground (27) during the steering manoeuvre.