Bucket Grade Control via Dynamic Edge Alignment
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Solution Overview
Problem
Existing grade control systems for machines with bucket implements, such as track-type loaders, face difficulties in aligning the bucket with a design plan when the bottom surface is parallel to it, especially when trying to penetrate hard-packed ground, as the bucket's large surface area prevents effective lowering.
Innovation Solution
A grading control system that uses two independent control loops to align the leading and trailing edges of the bucket implement, adjusting the angle of approach by selectively altering the gain of the control loops to realign the bucket with the design plan, allowing the bucket to penetrate the ground by tilting rather than relying solely on lift control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bucket is lowered toward the design plan with the bottom surface parallel to it, then the bucket can maintain stability and alignment, but the bucket is unable to penetrate hard-packed ground due to its large surface area
Solution Approach 1:
The system dynamically adjusts the bucket's orientation by transitioning from a parallel positioning mode to an angled approach mode. The control system modifies the bucket's angular position relative to the ground surface, enabling it to penetrate hard-packed ground by increasing the angle of approach while maintaining control through automated gain adjustment in the control loops.
Solution Approach 2:
The control system changes the operational parameters by adjusting the gain of the second control loop based on detected deviation from the design plan. This parameter adjustment allows the system to increase the angle of approach when the bucket is positioned above the design plan, enabling ground penetration while maintaining overall control and alignment capability.
2Device complexity
If the bucket bottom surface is kept parallel to the design plan for stable alignment, then alignment control is simplified, but the bucket cannot effectively penetrate hard-packed ground
Solution Approach 1:
The system implements dynamic control by switching between different control modes. When ground penetration is required, the system increases the angle of approach while automatically adjusting the control loop gains. This dynamic adaptation allows the bucket to effectively penetrate hard-packed ground without requiring complex manual intervention, as the control system automatically manages the transition and parameter adjustments.
3Productivity
If automatic leveling control is used to propel the machine about the worksite, then the machine can be efficiently repositioned, but the work attachment cannot be independently controlled to return to alignment with the design plan
Solution Approach 1:
The control system is segmented into two independent control loops: a first control loop for positioning the leading edge of the bucket and a second control loop for positioning the trailing edge. This segmentation allows independent control of different points on the work attachment, enabling the system to first align the leading edge with the design plan and then adjust the trailing edge to achieve complete alignment, thereby resolving the limitation of conventional automatic leveling control systems.
Data Source
AI summary
A method is disclosed. The method may include controlling a leading edge of an implement of a machine using a first control loop to cause the implement to align to a defined design plan; controlling a trailing edge of the implement of the machine using a second control loop to cause the implement to align to the defined design plan; and selectively altering a gain to the second control loop based on a detected deviation of the implement from the defined design plan to increase an angle of approach, using the first control loop, when the implement is positioned above the defined design plan and decrease the angle of approach, using the first control loop, when the implement is aligned to the defined design plan.