Hydraulic Actuator Calibration Using Neutral Valve Pump Mapping
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Solution Overview
Problem
Hydraulic excavators require lengthy calibration times for actuators, especially when replacing attachments with increased inertia, leading to inefficiencies and reduced accuracy.
Innovation Solution
Implement a system with variable displacement hydraulic pumps, regulators, directional control valves, and a controller that allows for calibration without actuator action by using a neutral position and generating an update-use conversion map.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed by outputting operation commands and acquiring stabilized cylinder speed, then calibration accuracy is maintained, but calibration time becomes excessively long
Solution Approach 1:
The system performs preliminary identification of actuator characteristics (such as cylinder speed vs. operation command value relationships) before actual calibration is needed. This pre-characterization data is stored and reused during calibration operations, eliminating the need to wait for speed stabilization during each calibration event.
Solution Approach 2:
The invention creates a model or map representing the actuator's characteristics based on initial measurements, then uses this copied information for subsequent calibration operations. This allows calibration to proceed using the stored characteristic data rather than requiring real-time stabilization measurements.
2Adaptability or versatility
If attachments with greater inertia are used, then work capability is improved, but the time to stabilize cylinder speed increases, extending calibration duration
Solution Approach 1:
The system performs preliminary identification of actuator characteristics (such as cylinder speed vs. operation command value relationships) before actual calibration is needed. This pre-characterization data is stored and reused during calibration operations, eliminating the need to wait for speed stabilization during each calibration event.
Solution Approach 2:
The system changes the operational parameters used for calibration by utilizing the pre-established characteristic maps and identification data, rather than relying on traditional methods that require waiting for physical stabilization. This allows calibration to proceed independently of the attachment's inertia characteristics.
3Reliability
If conventional calibration methods are used, then actuator speed control is achieved, but the process requires the actuator to perform actions, reducing operational efficiency
Solution Approach 1:
The invention creates a model or map representing the actuator's characteristics based on initial measurements, then uses this copied information for subsequent calibration operations. This allows calibration to proceed using the stored characteristic data rather than requiring real-time stabilization measurements.
Solution Approach 2:
The system replaces the traditional mechanical calibration approach (physically moving the actuator and measuring stabilized speeds) with a computational approach using stored characteristic maps and identification data. This substitution eliminates the need for physical actuator actions during calibration.
Data Source
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AI summary
An object of the present invention is to provide a work machine and an actuator calibration system which are capable of calibrating an actuator in a short time. To achieve this, a calibration device is configured to instruct a controller to transition to a calibration mode when instructed to perform a calibration of an actuator, in the calibration mode, cause a command value of a regulator that controls a pump flow rate to change in accordance with a predetermined pattern with a directional control valve being held in a neutral position, and, after instructing the controller to transition to the calibration mode, generate an update-use map in which a measured value of the pump flow rate is associated with the command value, and update a conversion map by using the update-use map.