Automatic Ground Speed Control for Work Vehicle Path Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tractors and similar work vehicles face challenges in maintaining direction along curved paths, especially at higher speeds, leading to excessive turning radius and path deviations, which require manual intervention to correct.
Innovation Solution
An automatic ground speed control system that uses a GPS guidance system to adjust wheel speed based on lateral path tracking error, upcoming path curvature, current location, and operator-defined speed limits, implemented through a software algorithm and electronic control unit connected to sensors and user interface, to maintain optimal speed and direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the tractor maintains higher ground speed, then productivity increases, but the turning radius increases causing path tracking errors
Solution Approach 1:
The system dynamically adjusts ground speed based on real-time path curvature information from the guidance system. When approaching tight turns or headland areas, the controller automatically reduces speed to maintain acceptable turning radius and path tracking accuracy, then restores speed on straight sections, creating a dynamic speed profile that adapts to changing geometric constraints
Solution Approach 2:
The system uses feedback from the guidance system about upcoming path geometry (curvature, turn radius, headland proximity) to proactively adjust speed before entering constrained areas. This closed-loop control ensures the tractor maintains accurate path following by continuously monitoring and responding to path tracking error and anticipated geometric constraints
2Manufacturing precision
If the tractor slows down for tight turns, then path tracking accuracy improves, but productivity decreases
Solution Approach 1:
The system performs preliminary speed reduction before the tractor enters tight turn zones or headland areas, based on advance knowledge of the guidance path geometry. This proactive approach allows smooth deceleration and acceleration cycles, minimizing the overall impact on productivity while ensuring accurate path following when needed
Solution Approach 2:
The system creates a dynamic speed profile that varies continuously along the guidance path, maintaining high speed on straight sections and reducing speed only in constrained areas. This dynamic adjustment minimizes the total time spent at reduced speeds, thereby reducing the overall impact on productivity while maintaining path tracking accuracy
3Ease of operation
If manual speed control is used, then operator flexibility is maintained, but operator workload increases and response time decreases
Solution Approach 1:
The system provides self-service by automatically monitoring the guidance path geometry and adjusting speed without operator intervention. The controller independently processes guidance data, determines appropriate speed adjustments, and executes them, freeing the operator from continuous manual speed management while maintaining flexibility through programmable control logic
Solution Approach 2:
The system implements automated feedback control where the controller continuously monitors path tracking error and upcoming geometric constraints from the guidance system, then automatically adjusts speed in response. This eliminates the need for constant operator attention and rapid manual responses, reducing workload and time loss while maintaining operational flexibility through configurable parameters
Data Source
AI summary
A method and apparatus for automatically controlling ground speed of a work vehicle. The apparatus includes a speed sensor generating a vehicle speed signal, the speed sensor operatively connected to a controller. A traction device angle sensor generates an angle signal which represents an angle of the traction device with respect to an axis of the work vehicle, wherein the traction device angle sensor operatively connected to the controller. A vehicle guidance system is configured to generate a vehicle position signal, wherein the controller determines the ground speed of the vehicle based on at least one of: i) a tracking error of the vehicle relative to the vehicle position signal; ii) a planned curved vehicle path; iii) a planned location of the vehicle within a defined portion of a field; and iv) a planned path segment and an associated change in direction of travel of the work vehicle.