Excavator Boom Speed Control for Bucket Edge Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In profile work with hydraulic excavators, the automatic control of the boom operation leads to instability of the bucket's cutting edge, causing hunting due to excessive vertical movement, especially when fine operations are performed with the arm control lever.
Innovation Solution
A work vehicle system that includes a speed limit determination portion to regulate the speed of the bucket's cutting edge based on its distance from the design surface, with a target speed determination portion adjusting the boom's speed to stabilize the cutting edge by limiting its movement, particularly during smaller arm operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If automatic control of the boom operation is implemented to prevent the bucket from entering the design topography, then the bucket position control is improved, but the cutting edge stability deteriorates causing hunting
Solution Approach 1:
The control system dynamically adjusts the boom operation based on the detected distance between the cutting edge and the design topography. When the distance is large, the boom operates at normal speed to maintain productivity. When the distance becomes small (approaching the design topography), the boom speed is automatically reduced to prevent hunting and ensure cutting edge stability. This dynamic adjustment resolves the contradiction by adapting the control strategy to the real-time operational context.
Solution Approach 2:
The system changes the operational parameters of the boom based on the distance to the design topography. Specifically, the boom speed parameter is modified according to the detected position: at normal distances, full speed is maintained; when approaching the design topography threshold, the speed parameter is reduced. This parameter change allows the system to maintain both precise position control and cutting edge stability by adjusting the boom's operational characteristics based on real-time feedback.
2Productivity
If the boom operation speed is increased to improve productivity, then the work efficiency is improved, but the cutting edge becomes unstable causing hunting
Solution Approach 1:
The system implements dynamic speed control where the boom operation speed is not fixed but varies based on the operational context. During normal excavation phases, the boom operates at high speed to maximize productivity. When the cutting edge approaches the design topography, the system automatically transitions to a reduced speed mode to prevent hunting. This dynamic speed adjustment allows the system to achieve both high productivity and cutting edge stability by adapting the boom speed to the real-time distance from the design surface.
Solution Approach 2:
The boom speed parameter is changed based on the detected distance to the design topography. The control system monitors the position continuously and adjusts the speed parameter accordingly: maintaining high speed when the distance is sufficient to ensure productivity, and reducing the speed parameter when the distance indicates proximity to the design topography to prevent hunting. This parameter-based control strategy enables the system to optimize both productivity and stability throughout the excavation process.
Data Source
AI summary
A work vehicle includes a boom, an arm, a bucket, an arm control member, a speed limit determination portion, and a target speed determination portion. The speed limit determination portion determines a speed limit for limiting a speed of a cutting edge of the bucket in accordance with a distance between a cutting edge and a design surface. The target speed determination portion determines a target speed of the boom based on the speed limit. The speed limit determination portion decides on a speed limit calculated based on correlation between the speed limit and the distance between the design surface and the cutting edge when an amount of operation of the arm control member is equal to or greater than a prescribed amount and decides on a speed limit lower than the speed limit calculated based on the correlation when the amount of operation is smaller than the prescribed amount.