Work Vehicle Control System for Smooth Excavation
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Solution Overview
Problem
Conventional systems for controlling work vehicles, such as bulldozers, face challenges in maintaining a smooth excavation operation and achieving high-quality finishes due to excessive load fluctuations, leading to irregular landscapes and reduced efficiency.
Innovation Solution
A control system that includes a storage device for current landscape information, sensors for excavation start position detection, and a controller that determines an inclination angle for a virtual design surface to match a target soil amount, allowing the work implement to move along this surface, thereby reducing load fluctuations and ensuring efficient excavation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If load controlling is used to reduce shoe slip by lifting the work implement upon excessive load increase, then shoe slip is reduced, but the landscape develops large irregularities and excavation smoothness deteriorates
Solution Approach 1:
The system performs preliminary action by detecting the excavation start position in advance and pre-calculating the virtual design surface with appropriate inclination angle before excavation begins. This allows the work implement to follow a pre-planned smooth trajectory rather than reacting to load changes during excavation, preventing both shoe slip and landscape irregularities.
Solution Approach 2:
The system changes parameters by determining an optimal inclination angle for the virtual design surface based on the amount of soil to be excavated. By adjusting this angle parameter, the system achieves a balance between preventing excessive load increases (which cause shoe slip) and maintaining excavation efficiency, thereby resolving the contradiction between reliability and manufacturing precision.
2Reliability
If the work implement is repeatedly lifted to control load, then shoe slip is reduced, but work operation efficiency decreases due to repeated lifting
Solution Approach 1:
The system performs preliminary action by pre-calculating the virtual design surface with an optimized inclination angle before excavation starts. This allows the work implement to follow a smooth, pre-planned path that prevents excessive load increases from the outset, eliminating the need for repeated reactive lifting and maintaining continuous efficient operation.
Solution Approach 2:
The system ensures continuity of useful action by enabling the work implement to move continuously along the virtual design surface without repeated interruptions for lifting. The pre-calculated inclination angle maintains optimal soil engagement throughout the excavation, keeping the useful cutting action continuous and efficient while preventing shoe slip.
3Productivity
If the virtual design surface inclination angle is increased to remove more soil, then excavation efficiency improves, but load applied to the work implement increases excessively causing shoe slip
Solution Approach 1:
The system applies parameter changes by determining an optimal inclination angle for the virtual design surface that balances two competing requirements: removing sufficient soil to maintain excavation efficiency while preventing excessive load increases that would cause shoe slip. This optimized parameter achieves both productivity and reliability simultaneously.
Solution Approach 2:
The system uses feedback by continuously monitoring the actual excavation progress and comparing it with the virtual design surface. The controller adjusts the work implement position based on this feedback to maintain the optimal inclination angle, ensuring that soil removal remains efficient while load stays within safe limits to prevent shoe slip.
4Reliability
If the virtual design surface inclination angle is decreased to reduce load, then shoe slip is prevented, but excavation efficiency decreases due to insufficient soil removal
Solution Approach 1:
The system applies parameter changes by calculating and setting an optimal inclination angle that prevents excessive load increases (avoiding shoe slip) while maintaining sufficient soil removal rate for efficient excavation. This optimized parameter simultaneously achieves both reliability and productivity without compromise.
Solution Approach 2:
The system uses feedback to continuously monitor both the load on the work implement and the excavation progress. Based on this feedback, the controller maintains the optimal inclination angle of the virtual design surface, ensuring that the work implement removes sufficient soil to maintain efficiency while keeping load within safe limits to prevent shoe slip.
Data Source
AI summary
A sensor outputs a signal indicating an excavation start position at which a work implement starts excavation. A controller determines an inclination angle of a virtual design surface so that an amount of soil between the virtual design surface extending from the excavation start position and a current landscape matches a predetermined target amount of soil. The controller generates a command signal that causes the work implement to move along the virtual design surface extending from the excavation start position in a direction inclined at the inclination angle.