Work Machine Excavation Velocity Control via Signal Weighting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing control systems for work machines like hydraulic excavators face difficulties in maintaining excavating shaping accuracy due to variations in operation velocities, especially when operating on vertical target surfaces, leading to impaired performance in semi-automatic excavating shaping work.
Innovation Solution
A work machine equipped with a posture detection device, design data input, and an information processing system that calculates and corrects velocity components to ensure the work point does not penetrate the target surface, by weighting operation signals from actuators contributing to excavation velocities, allowing for precise control of excavation velocities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the arm operation is used for excavating vertical target surfaces, then the bucket distal end velocity is oriented upward opposite from the excavating direction, but the perpendicular velocity becomes higher causing great variation in excavation velocity
Solution Approach 1:
The patent inverts the conventional approach by switching from arm operation to boom operation for vertical target surface excavation. This inversion changes the velocity vector orientation so that the bucket distal end velocity aligns with the excavating direction rather than opposing it, and reduces perpendicular velocity variation, thereby improving excavation shaping accuracy while maintaining productivity.
2Manufacturing precision
If the boom lowering operation is used to offset perpendicular velocity variation, then the excavation velocity varies greatly, but this makes it difficult to perform semi-automatic excavating shaping work at intended velocity
Solution Approach 1:
The patent introduces a feedback control mechanism that detects the actual excavation velocity and compares it with the intended velocity, then automatically adjusts the boom operation to compensate for deviations. This feedback loop enables semi-automatic excavating shaping work to be performed at the intended velocity by continuously correcting velocity variations, thereby improving ease of operation while maintaining accuracy.
3Ease of operation
If arm operation amount is slightly varied, then the perpendicular velocity varies greatly, but this impairs excavating shaping accuracy
Solution Approach 1:
The patent changes the operational parameter from arm operation to boom operation, which fundamentally alters the relationship between operation amount and perpendicular velocity. The boom operation exhibits lower sensitivity of perpendicular velocity to operation amount variations compared to arm operation, thereby improving excavating shaping accuracy while maintaining ease of operation through normal control variations.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a work machine with which an operator can easily perform semi-automatic excavating shaping work at an intended excavation velocity. An information processing device calculates a target velocity of a work point at a predetermined position on a work implement on the basis of each of operation signals of operation devices, calculates a distance between the work point and a target surface on the basis of posture information of driven members and position information of the target surface, corrects a velocity component of the target velocity, the velocity component being perpendicular to the target surface, according to the distance such that the work point does not penetrate the target surface, and performs, before calculating the target velocity, weighting on each of the operation signals of the operation devices according to contribution to a velocity component of the work point, the velocity component being parallel to the target surface, on the basis of the posture information of the driven members and the position information of the target surface.