Excavator Auto-Control Using Soil Interaction Force Feedback
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Solution Overview
Problem
Existing automatic operating devices for hydraulic excavators fail to generate appropriate excavation forces due to the lack of consideration for the characteristics of soil and sand, leading to inefficient excavation processes.
Innovation Solution
An automatic operating device that includes an acquisition part for actual position data, an estimation part for estimating actual position data using force data and interaction characteristics, a calculation part for calculating deviations, a computation part for computing estimative force data, a setting part for adjusting parameters, and an instructive value calculation part to provide instructive values to the working machine, ensuring appropriate force generation based on interaction characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the automatic operating device uses fixed excavation force settings, then the device complexity is reduced, but the excavation precision deteriorates because it cannot adapt to different soil characteristics
Solution Approach 1:
The control system dynamically adjusts excavation force based on real-time feedback from position sensors and interaction force sensors. The excavation force is not fixed but varies according to the deviation from target position and the actual interaction with soil, enabling adaptation to different soil characteristics while maintaining precise control.
Solution Approach 2:
The system implements closed-loop feedback control by continuously monitoring the actual position of the attachment, comparing it with the target position, and adjusting the excavation force accordingly. The feedback mechanism uses position deviation and interaction force data to optimize excavation parameters in real-time, improving precision without requiring overly complex predetermined control schemes.
2Manufacturing precision
If the automatic operating device considers soil characteristics and interaction forces, then the excavation precision is improved, but the device complexity increases due to multiple sensors and computation parts
Solution Approach 1:
The computation part serves multiple functions: it calculates excavation force based on position deviation, estimates interaction force with soil, determines optimal excavation parameters, and adjusts control signals. This multi-functionality reduces the need for separate dedicated components for each function, achieving high precision while managing system complexity through integrated design.
Solution Approach 2:
The system uses its own operational data (position, force measurements) to automatically adjust its excavation parameters without external intervention. The computation part processes the sensor data and self-regulates the excavation force, making the system adaptive to different soil conditions while maintaining a relatively simple control architecture.
3Ease of operation
If the hydraulic excavator uses predetermined target positions without considering soil characteristics, then the ease of operation is improved, but the productivity deteriorates due to inefficient excavation processes
Solution Approach 1:
The system pre-calculates optimal excavation parameters and target positions based on estimated soil characteristics before actual excavation begins. By anticipating the required excavation force and adjusting parameters in advance, the system maintains ease of automatic operation while improving excavation efficiency through soil-appropriate force settings.
Solution Approach 2:
The system dynamically changes excavation parameters (force, speed, depth) based on real-time soil interaction feedback. This parameter adaptation allows the excavator to maintain efficient excavation across different soil types while preserving the simplicity of automatic operation, as the parameter adjustments are made autonomously by the control system.
Data Source
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AI summary
An automatic operating device includes: a position estimation part that includes an interaction model, and calculates, as estimative position data, actual position data corresponding to force data which is input; a force computation part that includes a force computation model, calculates force data corresponding to a deviation which is input, and inputs the force data to the position estimation part; a database that stores a base parameter that is a parameter having been calculated in past; and a parameter setting part that calculates, on the basis of the base parameter, a target parameter corresponding to each of a norm y(t) of an actual position and a norm u(t) of a force, and sets the target parameter to a parameter of each of the interaction model and the force computation model.