Crane Hoist Pendulum Damping Through Target Speed Signal Filtering
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Solution Overview
Problem
Existing crane control systems require complex sensor technology and lengthy response times to effectively dampen or prevent pendulum movements, leading to operator fatigue and potential hazards from undesired swinging of the load handling device.
Innovation Solution
A method and device that filters out the natural frequency of the pendulum from the target speed signal using a frequency filter, allowing for dynamic and efficient damping without complex sensors, and optionally includes an acceleration-limiting ramp generator to process the signal before filtering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex sensor technology and lengthy response time systems are used for sway damping, then pendulum movements can be effectively dampened, but operator fatigue increases and response time becomes too slow
Solution Approach 1:
The patent replaces complex sensor-based mechanical sway damping systems with a signal processing approach. By filtering the target speed signal in the control system before it reaches the drive devices, the invention achieves pendulum damping without requiring additional sensors or complex mechanical intervention systems, thereby reducing response time and operator fatigue while maintaining damping effectiveness.
2Reliability
If complex sensor technology and lengthy response time systems are used for sway damping, then pendulum movements can be effectively dampened, but device complexity increases
Solution Approach 1:
The patent replaces complex sensor technology with a software-based signal filtering approach. The control system processes the target speed signal through filters that eliminate frequency components causing pendulum movements, achieving the same damping effect without adding physical sensors or complex mechanical devices to the crane system.
Solution Approach 2:
The patent introduces an intermediary signal processing step between the operator's control inputs and the drive device commands. By filtering the target speed signal in this intermediate stage, the system dampens pendulum movements without requiring direct intervention from complex sensor systems or additional hardware components.
3Productivity
If operator applies excessive acceleration for quick movement between target points, then productivity increases, but pendulum oscillations increase creating hazards
Solution Approach 1:
The patent applies preliminary action by filtering the target speed signal before it is executed by the drive devices. The signal filtering removes frequency components that would cause dangerous pendulum oscillations, allowing the operator to command quick movements between target points without creating hazardous oscillations, thus maintaining both productivity and safety.
Data Source
Figure 1
Figure 2~3(b)
Figure 4
AI summary
The invention relates to a method for controlling a hoist, such as a crane (1) or a cable excavator, wherein a load handling means (8) is mounted to a boom (3) in the manner of a pendulum, via a hoist cable (7), and the boom (3) and/or a trolley (9) which can travel on the boom (3) is moved by means of at least one drive device (6; 10), wherein, in order to move the load handling means (8), a target speed signal (v_target) is specified for the at least one drive device (6; 10), the natural frequency of the pendulum being filtered out of the specified target speed signal (v_target) by means of a filter (14) and the filtered target speed signal (v_target_transl) being used to control the at least one drive device (6; 10).