Tilt Rotator Control for Bucket Tooth Alignment Without Spill
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Solution Overview
Problem
In hydraulic excavators equipped with tilt rotators, there is a challenge in aligning the bucket's tooth direction with a predetermined plane without changing the opening direction of the bucket, which is essential for efficient excavation and loading operations while minimizing soil spillage.
Innovation Solution
A system that includes a processor to acquire sensor measurements, calculate the current posture of the work tool, determine a virtual rotation axis, and generate a control signal to rotate the work tool around the virtual axis, allowing the bucket's tooth direction to be aligned with a predetermined plane without altering the opening direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the bucket is rotated using conventional rotation mechanisms to align the tooth direction horizontally, then the tooth direction can be aligned with the predetermined plane, but the opening direction of the bucket changes which reduces excavation efficiency
Solution Approach 1:
The system dynamically determines a virtual rotation axis based on the current posture of the work tool, allowing the rotation axis to adapt to the bucket's orientation. This enables alignment of the tooth direction with the predetermined plane while maintaining the opening direction, resolving the contradiction between ease of alignment operation and excavation efficiency.
Solution Approach 2:
The control system changes the parameter of rotation axis orientation by determining a virtual rotation axis that passes through the distal end of the work equipment and is orthogonal to both the current opening direction and the gravity direction. This parameter change enables precise control of the rotation operation to achieve tooth direction alignment without altering the opening direction, thus maintaining excavation efficiency while improving alignment operation.
2Adaptability or versatility
If multiple rotation mechanisms are used to control the bucket orientation, then the bucket can be directed in any direction, but the complexity of the control system increases
Solution Approach 1:
The invention extracts and utilizes the gravity direction as a reference, determining the virtual rotation axis based on the cross product of the opening direction and gravity direction. This approach simplifies the control system by using naturally available reference (gravity) rather than requiring complex multi-axis control mechanisms, reducing device complexity while maintaining full adaptability of bucket orientation.
Solution Approach 2:
The virtual rotation axis acts as an intermediary that connects the opening direction and the desired tooth direction alignment. By introducing this intermediate reference axis determined from gravity and opening direction, the system achieves precise control with simpler logic, reducing control system complexity while maintaining versatility in bucket orientation capability.
3Productivity
If the bucket is moved in a state where the width direction is not horizontal, then the bucket can maintain its opening direction for excavation efficiency, but soil spills out during transport to the dump truck
Solution Approach 1:
The system dynamically adjusts the bucket orientation by determining a virtual rotation axis based on current posture and gravity direction. This dynamic control enables the bucket to maintain horizontal tooth direction alignment during transport, preventing soil spillage, while preserving the opening direction for excavation efficiency, thus resolving the contradiction between productivity and soil spillage prevention.
Data Source
AI summary
A measured value acquisition unit acquires measured values from a plurality of sensors. A position and posture calculation unit calculates a current posture of the work tool, based on the measured values. A target posture determination unit determines a virtual rotation axis, based on the calculated current posture of the work tool, when a predetermined control start condition is satisfied. A rotation amount calculation unit generates a control signal of the tilt rotator for rotating the work tool from the current posture to a target posture by a predetermined amount around the virtual rotation axis. A control signal output unit outputs the generated control signal.