Tractor Hitch Control System Braking Logic
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Solution Overview
Problem
Existing tractor linkage control systems face challenges in safely managing draft forces during braking, leading to unintentional movement of implements due to changes in CVT pressure, especially when the tractor is braking, which can result in collisions or damage.
Innovation Solution
A hitch control system that senses braking through a brake lever or sensor and ignores changes in pull/drag force during braking, maintaining the linkage in its current position to prevent unintended movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If draft control mode is activated to automatically adjust linkage position based on drag force, then implement working quality and operator comfort are improved, but unintentional movement of linkage occurs during braking causing collisions or damage
Solution Approach 1:
The control unit continuously monitors brake actuation status and uses this feedback to modify draft control behavior. When braking is detected, the system adjusts its response to drag force changes, preventing unintentional linkage movement while maintaining normal draft control functionality during non-braking operations.
Solution Approach 2:
The system dynamically adjusts its control characteristics based on operating conditions. During braking, the draft control mode temporarily modifies its responsiveness to drag force changes, transitioning from automatic position adjustment to a more stable state that prevents collisions, while returning to normal operation after braking ceases.
2Extent of automation
If CVT pressure is used to detect drag force for draft control, then automatic implement depth control is achieved, but pressure changes during braking are misinterpreted as drag force changes causing linkage movement
Solution Approach 1:
The control unit acts as an intermediary between CVT pressure sensing and linkage control. It filters out pressure changes caused by braking by monitoring brake actuation status, thereby distinguishing between genuine drag force changes (from implement resistance) and false signals (from braking) before activating draft control responses.
Solution Approach 2:
The system changes the interpretation parameters of CVT pressure based on brake status. When braking is detected, the control unit modifies how pressure changes are translated into linkage position commands, effectively decoupling pressure variations caused by braking from the drag force measurement chain to prevent false linkage movement.
Data Source
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AI summary
A hitch control system for a tractor comprising means to create a force signal indicative of the current pull force necessary to pull an implement attached to a hitch and a control means which receives the force signal and inputs entered by a tractor operator indicative of the required operating condition of the implement. The system adjusts the vertical position of the hitch relative to the tractor in response to the variations in the force signal in order to try to maintain the required operating condition of the implement. The system further comprises a brake sensing means which provides a brake signal to the control means indicative of the application of the brakes and wherein during the detection of the brake signal, the change in force signal is ignored and there is no movement of the hitch.