Forest Machine Crane Speed Control via Sensor Feedback
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Solution Overview
Problem
Existing forest-machine cranes experience sensitivity in motion speed adjustment due to angles between boom parts and distance from the fastening point, making operator control demanding and stressful, especially when moving the crane head horizontally far from the work machine.
Innovation Solution
A crane with an adjuster device using measurement data from sensors to adjust motion speed, ensuring consistent speed across control lever positions, reducing oscillation and enabling combined motions, automatic load stability, and weighing, thereby simplifying operator control and preventing dangerous operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If stepless motion speed adjustment of hydraulic cylinders is implemented, then the suitable motion speed can be adjusted irrespective of crane head location, but the motion speed becomes extremely sensitive to control lever changes when the crane head is far from the work machine
Solution Approach 1:
The system uses sensors to detect the actual position of the crane head and feeds this information back to the control system. The control lever position is then adjusted based on this feedback to compensate for the geometric relationships between boom parts, ensuring that the motion speed remains consistent and predictable regardless of the crane head's location. This feedback mechanism eliminates the sensitivity problem by continuously adapting the control signal.
Solution Approach 2:
The invention changes the control parameter from direct hydraulic cylinder speed control to a modified control approach that accounts for boom angle and crane head position. By adjusting the control lever position dynamically based on sensor data, the system maintains a constant and predictable motion speed relationship between the control input and the crane head movement, regardless of the geometric configuration.
2Length of moving object
If the crane head is moved far from the work machine horizontally, then the working range is increased, but the motion speed becomes excessively sensitive to small control lever changes
Solution Approach 1:
Sensors detect the actual position of the crane head and provide feedback to the control system. The control system uses this feedback to adjust the control lever position dynamically, compensating for the increased geometric sensitivity that occurs at greater distances. This ensures that the motion speed remains stable and predictable even when the crane head is positioned far from the work machine.
Solution Approach 2:
The system performs preliminary calculations based on sensor data about the current boom angles and crane head position before executing the motion control. By anticipating the geometric relationships and pre-adjusting the control signals, the system prevents excessive sensitivity from occurring in the first place, maintaining reliable motion speed control throughout the extended working range.
Data Source
Figure 1
AI summary
The invention relates to a crane for a forest machine (1), which includes a lifting boom (5) rotatably fastened to a work machine with a rotatable fastening device (3) and a transfer boom (7) rotatably fastened in it as well as a fastening element (10) fastened at the end of the transfer boom for fastening a harvester head (11), a timber loader or equivalent. In the crane for a forest machine (1) according to the invention, there is at least one measuring sensor (13) for determining a distance of the crane head and/or angles (α) between the fastening device (3), the lifting boom (5) and/or the transfer boom (7) and the crane for a forest machine (1) includes an adjuster device (12) for adjusting the motion speed of the crane head based on measurement data received from the measuring sensor (13).