Crane Load Positioning via Rotary Mechanism Control
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Solution Overview
Problem
Existing methods for positioning a crane load on a cable suspension in a crane system are complex and require significant effort, especially when adjusting the angle of rotation about its vertical axis, often leading to unwanted torsional oscillations.
Innovation Solution
The method uses the angular position of the slewing gear and the absolute angle of rotation of the upper part of the load handling device as input variables, along with the vertical distance between the crane trolley and the upper part of the load handling device, to control the slewing gear, eliminating independent constant angular components and allowing for automatic or manual positioning without additional sensor units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the absolute angle of rotation of the lower part of the load-carrying means is used as input variable, then the positioning can be performed, but the sensor arrangement becomes complex and difficult to detect in every position
Solution Approach 1:
The patent extracts and eliminates the constant angular component from the input variable. Instead of using the absolute angle of rotation of the lower part (which requires complex sensor arrangements to track in all positions), the system uses only the oscillating angular component of the upper part. This extraction of the problematic constant component simplifies the sensor arrangement while maintaining positioning capability.
Solution Approach 2:
The patent inverts the conventional approach by measuring the angle at the upper part (crane system side) rather than the lower part (load-carrying means side). This inversion allows the use of a fixed sensor arrangement on the crane system that remains in a detectable position throughout operation, eliminating the need for complex moving sensor arrangements.
2Measurement precision
If sensor elements are arranged on the lower part of the load-carrying device, then the positioning can be controlled, but complex measures are required to ensure continuous detection
Solution Approach 1:
The patent inverts the sensor arrangement location from the lower part to the upper part of the load handling device. By placing the sensor on the upper part (which is stationary relative to the crane system), continuous detection is achieved without complex measures, as the sensor remains in a fixed, easily accessible position throughout the operation.
3Ease of operation
If manual positioning is used, then the operator can control the rotation, but the process requires significant effort and time
Solution Approach 1:
The patent implements a feedback control system that automatically adjusts the slewing gear based on the detected angular position of the upper part. The control unit continuously monitors the oscillating angle and automatically positions the load, eliminating the need for manual operation and significantly reducing positioning time while maintaining precision.
Solution Approach 2:
The system performs self-positioning by automatically detecting its own angular position through the sensor and adjusting the slewing gear accordingly. This self-service capability eliminates the need for external manual intervention, reducing both operator effort and positioning time.
Data Source
AI summary
The method involves adjusting a rotational angle of a crane load (2) by manual presetting of a rotational speed reference value for a rotary mechanism (11) arranged between the crane load and a cable suspension (10) of a crane (5). The rotary mechanism is regulated with the variation of the rotational angle of the crane load based on the angular position of the rotary mechanism, an absolute rotational angle of an upper part (12a) of a load carrying device (4) and a vertical distance between a crane jack (6) and the upper part. An independent claim is also included for a device for positioning a crane load hanging at a cable suspension of a crane in a direction of rotation around a vertical axis of a cable suspension.