Excavator Controller Dynamic Jack-Up Angle Adjustment
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Solution Overview
Problem
Operators of hydraulic excavators face poor operability and difficulty in adjusting excavating force due to the inability to intuitively grasp the jack-up angle, as existing technologies maintain a zero jack-up angle, limiting their control over the machine's jacked-up state.
Innovation Solution
A work machine with a controller that performs area restriction control, allowing the jack-up angle to vary based on the arm's posture, enabling the machine to operate on or above a target surface and adjusting hydraulic cylinder control to maintain a preset target jack-up angle, enhancing operator control and work efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the boom cylinder pressure is always controlled to maintain zero jack-up angle, then the machine body is prevented from jacking up, but the operator cannot intuitively grasp the excavating force state and adjust the excavating force
Solution Approach 1:
The patent applies dynamics by making the target jack-up angle variable rather than fixed at zero. The controller dynamically adjusts the target jack-up angle based on the arm's posture (extension angle), allowing the system to adapt between stability and operator controllability. This resolves the contradiction by enabling the machine to maintain stability when needed while allowing operator intervention when required.
Solution Approach 2:
The patent changes the parameter of target jack-up angle from a constant zero value to a variable value that depends on arm posture. By changing this control parameter dynamically, the system can transition between two operational modes: maintaining zero jack-up angle for stability during normal operation, and allowing positive jack-up angles for operator control during force adjustment needs.
2Productivity
If machine control maintains zero jack-up angle, then the work device operates smoothly on the target surface, but the operator loses the ability to adjust excavating force by varying the jack-up angle
Solution Approach 1:
The system dynamically switches between automated surface-following control and operator-adjustable control based on the operational context. When the arm is extended, the system allows positive jack-up angles for operator flexibility. When the arm is retracted, the system maintains zero jack-up angle for efficient surface following, thus resolving the contradiction between productivity and adaptability.
Solution Approach 2:
The control parameter (target jack-up angle) is changed from a fixed zero to a variable value that depends on arm extension angle. This parameter change enables the system to provide both efficient automated operation and operator flexibility, resolving the contradiction between productivity and adaptability.
3Stability of the object's composition
If the jack-up angle is always kept at zero, then the machine body remains stable, but the operator cannot intuitively grasp the excavating force magnitude from the jack-up angle
Solution Approach 1:
The system provides feedback to the operator through the visual indication of the jack-up angle on the display. When the operator increases excavating force, the jack-up angle increases, providing immediate visual feedback about the force magnitude. This feedback mechanism resolves the information loss while maintaining stability through controlled operation.
4Manufacturing precision
If area restriction control is performed to keep the work device on the target surface, then excavation precision is improved, but the operator loses control over the jack-up angle variation
Solution Approach 1:
The area restriction control is made dynamic by allowing the target surface to be defined by variable jack-up angles rather than a fixed zero angle. This enables the control system to maintain precision while allowing operator control freedom, as the dynamic adjustment of target angles accommodates both precise surface following and operator intentions.
Data Source
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AI summary
A work machine includes a controller (20) that performs an area restriction control for controlling at least one hydraulic cylinder (32a) of a plurality of hydraulic cylinders (32) in such a manner that a work device (400) is located on or on an upper side of an optionally set target surface (60) during operation of an operation lever (26). In the work machine, if a jack-up angle (ϕ) as an inclination angle of a machine body (1A) relative to a ground is larger than a preset target value (ϕt), the controller, in performing the area restriction control, corrects the control of the at least one hydraulic cylinder (32a) in such a manner that the jack-up angle approaches the target value. The target value is set such as to vary according to posture of an arm (406).