Excavator End-Effector Control Using Impact Sensor Feedback
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Solution Overview
Problem
Existing excavator control systems struggle to precisely control the end-effector's movement along a target trajectory during digging, leading to potential damage and inefficiencies due to abrupt changes in end-effector force without timely adjustments.
Innovation Solution
A method and system that utilize motion-control algorithms, sensor data from movement and impact sensors, and a movement model to estimate the end-effector force and adapt control commands in real-time, ensuring the end-effector follows the desired trajectory and adjusts to changes in ground resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional hydraulic control commands are used without real-time adaptation, then the control system remains simple and responsive, but the end-effector velocity is abruptly reduced when ground resistance increases, causing shocks and potential damage
Solution Approach 1:
The control system continuously monitors end-effector velocity and ground resistance, using this feedback to dynamically adjust hydraulic control commands. This closed-loop approach prevents abrupt velocity reductions and shocks while maintaining system reliability, resolving the contradiction between simple control and damage prevention.
Solution Approach 2:
The system proactively adjusts control commands before abrupt velocity changes occur by monitoring trends in ground resistance and predicting potential shocks. This preliminary adaptation prevents damage while maintaining relatively simple control architecture.
2Productivity
If the end-effector force is increased without timely adjustment of movement, then digging power is improved, but the end-effector is deflected from its target trajectory and the desired design surface is not obtained
Solution Approach 1:
The system monitors both end-effector position relative to target trajectory and ground resistance forces, using this feedback to dynamically adjust control commands. This ensures digging power is optimized while maintaining trajectory accuracy and achieving the desired design surface.
Solution Approach 2:
The control system dynamically changes multiple parameters including hydraulic pressure, end-effector velocity, and bucket angle in response to ground resistance variations. This coordinated parameter adjustment maintains both digging power and trajectory precision.
3Productivity
If the operator manually adjusts control commands in response to ground resistance changes, then excavation efficiency is improved, but operator stress increases and errors may occur
Solution Approach 1:
The control system automatically monitors ground resistance and adjusts hydraulic commands without operator intervention. This self-adjusting capability maintains high excavation efficiency while eliminating operator stress and manual adjustment errors, fully resolving the contradiction between productivity and ease of operation.
Solution Approach 2:
The system uses continuous feedback from sensors monitoring ground resistance and end-effector performance to automatically adjust control parameters. This automated feedback loop achieves efficient excavation while reducing operator workload to minimal supervision.
4Manufacturing precision
If a two-step workflow of coarse and subsequent fine excavation is used, then precision is achieved, but time and resources are wasted
Solution Approach 1:
The control system continuously monitors end-effector position relative to the target trajectory and dynamically adjusts control commands to maintain precision throughout the entire excavation process. This eliminates the need for separate fine-tuning passes, achieving design surface precision in a single pass while reducing time and resource consumption.
Solution Approach 2:
The system maintains continuous precision control throughout the excavation process rather than relying on discrete coarse and fine passes. This continuous adaptation keeps the end-effector on target throughout, eliminating idle time between workflow stages and reducing total excavation time.
Data Source
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AI summary
The present invention relates to a method for controlling movement of an end-effector 4 of an excavator 1, wherein the end-effector 4 is attached to the excavator 1 via an articulated component comprising multiple links 2,3, wherein the method comprises providing motion commands for moving the end-effector 4, using a motion-control algorithm to translate the motion commands to control commands for moving the multiple links 2,3 with respect to each other so that the end-effector 4 moves with a target trajectory 10 associated with the motion commands, accessing movement sensor data 11 configured to provide monitoring of a movement of the articulated component and the end-effector 4, accessing impact sensor data 12 comprising hydraulic pressure sensing data and/or force sensor data, using the movement sensor data 11 and the impact sensor data 12 to determine an estimated value of an impact parameter 13 for the articulated component, wherein the impact parameter 13 provides information on an end-effector force exerted by a contact-component 27 of the end-effector 4 specifically foreseen for interaction with material 21 to be moved by the end-effector 4 and/or an information on a load exerted on one of the multiple links 2,3, and providing adapted control commands by using a movement model for the articulated component configured to provide coordination of control commands of the multiple links as a function of the estimated value of the impact parameter 13.