Excavator Boom Control Across Design Face Junctions
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Solution Overview
Problem
Existing excavation control systems for hydraulic excavators face challenges in preventing the bucket from entering design faces with different inclinations when passing through junctions, leading to sudden velocity changes and potential bucket intrusion, which can result in reduced work efficiency and increased operator burden.
Innovation Solution
A work machine with a controller that generates a supplemented design face passing through or above the junction between adjacent design faces, setting its curvature based on the operation amount, and executing semi-automatic excavation control to maintain the working point on or above the target face, thereby preventing bucket intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the limit velocity is selected based on the closer design face or greater boom raising velocity, then the bucket can be prevented from entering design faces under normal conditions, but the target velocity suddenly changes when passing through junctions, causing the bucket to possibly enter design faces
Solution Approach 1:
The system performs preliminary actions by predicting the bucket's future position based on current velocity and operation amount before the bucket actually reaches the junction. This allows the control system to prepare appropriate velocity commands in advance, avoiding sudden changes when the bucket crosses the junction between design faces.
Solution Approach 2:
The system dynamically adjusts the velocity command based on real-time conditions including operation amount, bucket position, and predicted trajectory. By making the velocity command adaptive rather than fixed, the system maintains stability during junction transitions while still preventing bucket intrusion into design faces.
2Reliability
If the operator reduces arm velocity to prevent bucket intrusion, then the bucket can be kept from entering design faces, but the work amount is reduced and operation becomes cumbersome
Solution Approach 1:
The control system automatically adjusts the velocity command to prevent bucket intrusion without requiring the operator to manually reduce operation intensity. The system serves itself by detecting potential intrusion risks and autonomously correcting the velocity, eliminating the need for cumbersome operator interventions while maintaining full work efficiency.
3Reliability
If the target velocity is suddenly changed at design face junctions, then the control can respond to new constraints, but the actual boom motion cannot follow up, allowing bucket intrusion
Solution Approach 1:
By calculating the predicted bucket position in advance and determining appropriate velocity commands before the bucket reaches the junction, the system avoids sudden target velocity changes. This preliminary calculation ensures that velocity transitions are smooth and within the boom's response capabilities, maintaining both constraint compliance and physical feasibility.
Solution Approach 2:
The system applies partial correction to the velocity command based on the predicted trajectory and operation amount, rather than making excessive or abrupt changes. This moderate adjustment approach ensures that the boom can follow the velocity commands while still preventing bucket intrusion into design faces.
Data Source
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AI summary
A main controller generates a supplemented design face that passes through a junction or above the junction between a first design face and a second design face adjacent to each other, among a plurality of design faces, the supplemented design face having one end thereof positioned on the first design face and another end thereof positioned on the second design face, sets a curvature 1/R of the supplemented design face according to an arm operation amount of an operation lever device, and executes semi-automatic excavation control to control a boom cylinder with one of the faces included in the supplemented design face being set as the target face.