Blade Control System for Construction Machine Dozing
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Solution Overview
Problem
Existing dozing control systems for construction machines fail to maintain a flat dozed surface when dealing with wavy contours, resulting in a wavy dozed surface even when the target contour is flat.
Innovation Solution
A blade control system that includes a lift frame, a blade, a lift cylinder, a control valve, and various calculating and regulating components to maintain the blade load close to a target value and adjust the blade angle to match the slope angle of the designed surface, preventing the formation of a wavy contour.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the blade load is strictly maintained at the target value, then dozing efficiency is improved, but the dozed surface becomes wavy when the object has wavy contour
Solution Approach 1:
The control system dynamically switches between two control modes: load control mode (for efficiency) and angle control mode (for surface quality). The blade lifting angle is adjusted based on the difference between the current blade angle and the slope angle of the designed surface, allowing the system to adapt to wavy contours while maintaining overall efficiency.
Solution Approach 2:
The control parameter is changed from blade load to blade lifting angle when the blade load is within the predetermined range. This parameter substitution allows the blade to follow the designed surface contour (matching the slope angle) rather than strictly maintaining target load, thereby preventing wavy surface formation.
2Manufacturing precision
If the blade lifting angle is adjusted to match the slope angle of the designed surface, then surface flatness is improved, but dozing efficiency decreases when blade load deviates from target value
Solution Approach 1:
The control mode is dynamically selected based on the blade load condition. When blade load is within the predetermined range, angle control is applied for surface quality. When blade load is outside the range, load control is applied for efficiency. This dynamic switching resolves the contradiction by applying the appropriate control strategy based on real-time conditions.
Solution Approach 2:
The primary control parameter is switched between blade load and blade lifting angle depending on the operational context. This parameter change allows the system to prioritize surface flatness when load conditions permit, while maintaining efficiency when load deviation occurs.
3Productivity
If the blade load is promptly regulated to target value, then dozing efficiency is improved, but the blade cutting edge cannot follow the designed surface contour
Solution Approach 1:
The control system applies angle control (prioritizing contour accuracy) when blade load is within the predetermined range, and load control (prioritizing efficiency) when outside the range. This dynamic approach allows the blade to follow the designed surface contour during stable operation while maintaining efficiency during transient conditions.
Solution Approach 2:
The control parameter is changed from load to angle when operating within the load range, enabling the blade angle to be regulated for making the sum of the forwardly inclined angle and blade lifting angle gradually get closer to the slope angle of another designed surface, thereby following the contour accurately.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system efficiently dozes the surface by keeping the blade load close to the target value and adjusting the blade angle to match the slope, preventing a wavy contour and ensuring a smooth transition between different dozed surfaces.
Implementation Method 1
a lift cylinder configured to vertically drive the lift frame
Implementation Method 2
a control valve configured to supply a hydraulic oil to the lift cylinder
Data Source
AI summary
A blade control system includes a first open ratio setting part for setting a first open ratio of a proportional control valve based on a difference angle between a blade angle and a slope angle; a second open ratio setting part for setting a second open ratio of the proportional control valve based on a difference load between a blade load and a target blade load; and a lift controlling part for controlling the proportional control valve in accordance with the second open ratio when the blade load is out of a predetermined load range and for controlling the proportional control valve in accordance with the first open ratio when the blade load is within the predetermined load range.