Work Machine Controller Speed Limiting for Grading Shock Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The rapid speed change during intervention control in work machines, particularly when the dipper stick approaches its stroke end, leads to shocks and affects the accuracy of land grading, causing discomfort and reducing service efficiency.
Innovation Solution
A work machine with a controller that reduces the speed of the work implement before completing intervention control, using a speed limit table to gradually decelerate the boom speed as it approaches the stroke end, thereby minimizing shock and maintaining control precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If intervention control is performed to shift the bucket along a boundary surface, then the accuracy of land grading is improved, but a rapid change of cylinder speed occurs when the dipper stick arrives at a position close to the stroke end, causing shock to the work machine
Solution Approach 1:
The controller performs preliminary action by stopping the intervention control before the dipper stick arrives at the stroke end position. This preventive measure avoids the rapid cylinder speed change that would otherwise occur, thereby eliminating the shock to the work machine while maintaining land grading accuracy through prior intervention control
Solution Approach 2:
The controller applies preliminary anti-action by preemptively stopping the intervention control before the harmful condition (rapid speed change at stroke end) occurs. This counteracts the potential shock by reversing the control action in advance, preventing the adverse effect while preserving the beneficial land grading accuracy
2Manufacturing precision
If the intervention control is stopped when the dipper stick arrives at a position close to the stroke end, then the accuracy of land grading is maintained, but the rapid speed change of the work implement applies shock to the work machine
Solution Approach 1:
The controller executes preliminary action by halting intervention control before the dipper stick reaches the stroke end position. This advance stopping prevents the rapid cylinder speed change and associated shock force, while the prior intervention control ensures land grading accuracy is achieved
3Object-affected harmful factors
If the speed of the work implement is reduced before completion of intervention control, then the shock applied to the work machine is reduced, but the intervention control is stopped before completion
Solution Approach 1:
The controller performs preliminary action by stopping intervention control before the dipper stick arrives at the stroke end position. This timing allows speed reduction to be implemented in advance, reducing shock while the interruption is minimal since the control stops just before the harmful condition would occur
Data Source
AI summary
A work machine according an aspect includes a work implement, an operation apparatus for operating the work implement, and a controller for controlling the work implement. The controller performs intervention control for lowering the work implement based on an operation command from the operation apparatus, and reduces a speed of the work implement during the intervention control to stop the work implement before completion of the intervention control.