Work Machine Swing Range Control After Position Signal Loss
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Solution Overview
Problem
Existing control systems for work machines, such as those described in Patent Document 1, terminate excavation control when the swing structure is swung, leading to a decrease in work efficiency as excavation control cannot be performed until target excavation terrain profile information is reobtained.
Innovation Solution
A work machine equipped with a swing structure, position sensor, posture sensor, and a controller that stores reference swing angle information when position information is unavailable, allowing machine control to resume once the swing structure is within a predefined swing range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the control system ends retention of target excavation terrain profile information when the swing structure is swung, then the system ensures accurate control based on valid position data, but work efficiency decreases because excavation control cannot be performed until position information is reobtained
Solution Approach 1:
The control system performs preliminary actions by storing the last valid target excavation terrain profile information before position information becomes unavailable, and by pre-defining a swing range based on stored reference swing angle information. This allows the system to maintain excavation control throughout the swing operation without interruption, resolving the contradiction between ensuring control accuracy and maintaining work efficiency.
2Productivity
If the control system continues excavation control using retained target excavation terrain profile information when position information is unavailable, then work efficiency is maintained, but control reliability decreases when the swing structure moves outside the valid range
Solution Approach 1:
The control system implements feedback by continuously monitoring the swing angle through the posture sensor and comparing it against the pre-defined swing range based on reference swing angle information. When the swing structure remains within the valid range, excavation control continues using retained target excavation terrain profile information. When the swing structure moves outside the range, the system automatically terminates the control, ensuring both work efficiency and control reliability.
3Device complexity
If the control system uses a fixed time retention period for target excavation terrain profile information, then the system simplifies the control logic, but it cannot adapt to varying swing durations and loading operations
Solution Approach 1:
The control system applies dynamics by replacing the fixed time retention period with a dynamic swing range-based approach. The retention of target excavation terrain profile information is now governed by the real-time swing angle monitored through the posture sensor, allowing the system to adapt to varying swing durations and loading operations. This dynamic approach maintains simple control logic while significantly improving adaptability to different operational conditions.
Data Source
AI summary
A work machine includes a swing structure, a work device, a position sensor, a posture sensor and a controller that performs machine control on the basis of a target surface set on the basis of target shape data, the position information of the swing structure, and the information about the posture of the work machine. When the controller becomes unable to obtain the position information of the swing structure, the controller stores swing angle information of the swing structure, the swing angle information being sensed by the posture sensor at that time. The controller prohibits execution of the machine control when the swing structure is positioned outside a swing range; and permits the execution of the machine control when the swing structure is positioned inside the swing range and when the swing structure is positioned inside the swing range again after being positioned outside the swing range.