Agricultural Steering System With Adjustable Actuation Behavior
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing agricultural vehicle steering systems lack an adjustable actuation behavior for the steering wheel, leading to a lack of haptic feedback and the inability to turn the steering wheel beyond its mechanical stop, which can result in driver confusion and reduced operational safety.
Innovation Solution
A steering system with a control device that can simultaneously control three switching valves using a singular electrical signal, allowing for adjustable actuation behaviors such as endless steering wheel rotation and increased resistance, and the ability to simulate reaching a steering stop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the steering wheel is connected to a hydraulic device (orbitrol) for hydraulic steering, then the driver receives haptic feedback and steering resistance, but the steering wheel cannot be turned beyond the mechanical stop position and the driver experiences counter-torque that does not reflect the actual steering state
Solution Approach 1:
The patent introduces a switching valve as an intermediary component that can redirect the hydraulic fluid flow from the orbitrol back to the hydraulic device, bypassing the steering cylinders. This allows the steering wheel to be decoupled from the mechanical steering stop while maintaining hydraulic feedback through the orbitrol, resolving the contradiction between operability and feedback accuracy.
Solution Approach 2:
The system dynamically switches between two operational modes: a first mode where the steering wheel is mechanically coupled to the steering cylinders with full hydraulic feedback, and a second mode where the steering wheel can rotate beyond the mechanical stop while maintaining hydraulic feedback through the orbitrol. This dynamic switching resolves the contradiction by adapting the system behavior to different operational requirements.
2Reliability
If the steering system uses a fixed hydraulic connection between the orbitrol and steering cylinders, then the driver receives consistent hydraulic feedback, but the system lacks versatility for different steering modes and driver preferences
Solution Approach 1:
The patent implements a dynamic switching mechanism that allows the steering system to transition between a first steering mode with full hydraulic feedback through the steering cylinders and a second steering mode where the fluid flows directly back to the hydraulic device. The switching valve enables this dynamic reconfiguration, providing both consistency and flexibility.
Solution Approach 2:
The steering system is designed to perform multiple functions through the switching valve: it can operate in a first mode with traditional hydraulic steering feedback, or switch to a second mode where the orbitrol fluid flows directly back to the hydraulic device while maintaining feedback. This multi-functionality resolves the contradiction between reliability and adaptability.
3Ease of operation
If the steering system allows the steering wheel to rotate beyond the mechanical stop, then the driver experiences improved ease of operation, but the driver loses haptic feedback indicating the maximum steering angle has been reached
Solution Approach 1:
The switching valve acts as an intermediary that enables the steering wheel to rotate beyond the mechanical stop by redirecting hydraulic fluid flow through the orbitrol back to the hydraulic device, while the orbitrol itself serves as the mediator providing continuous haptic feedback to the driver about the steering angle, preventing loss of information.
Solution Approach 2:
The system maintains feedback through the orbitrol hydraulic connection even when the steering wheel rotates beyond the mechanical stop. The orbitrol provides continuous haptic feedback to the driver, ensuring that steering angle information is not lost while allowing extended rotation range for improved ease of operation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a steering system (1) for an agricultural vehicle, comprising: - at least one primary-controlled axle and at least one further axle, each of which is assigned at least one steering cylinder (2) for changing a wheel steering angle, - a valve unit (4) connected to a supply unit (3) for pressurizing the steering cylinders (2), - at least one control device (13, 18) configured to actuate the first steering control and switching unit (5), wherein the steering system (1) is operable in a first steering mode and at least one further steering mode, wherein the at least one control device (13, 18) is configured to sensorially detect a steering movement (20) of a steering wheel (19) connected to the second steering control and switching unit (8) in the first steering mode and to transmit it as a steering angle setpoint signal to the first steering control and switching unit (5), wherein the at least one control device (13,18) is designed to simultaneously control at least three switching valves (10, 11, 12) in the first steering mode by means of a single signal in order to set at least one steering wheel actuation behavior (19).