Crane Speed Profile Filtering for Load Swing Suppression
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Solution Overview
Problem
Conventional cranes face difficulties in suppressing load swing during automated conveyance along a set path, as existing control methods are inefficient in preventing swing without causing it.
Innovation Solution
A control apparatus for cranes that calculates target conveyance time and speed for each section of a conveyance path, subdivides sections into acceleration, constant-speed, and deceleration sections, and applies a low-pass filter to convert stepwise target speed signals into non-stepwise signals to control the crane, thereby reducing load swing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is used to detect and control load swing after it occurs, then load swing can be suppressed when caused, but it is difficult to perform control without causing load swing in the first place
Solution Approach 1:
The control apparatus performs preliminary action by calculating target conveyance times and target speeds for each section before automated conveyance begins. The conveyance path is divided into multiple sections with different target conveyance times, and target speeds are calculated in advance based on section distances and target times. This preliminary planning prevents load swing from occurring in the first place, rather than merely suppressing it after detection.
Solution Approach 2:
The conveyance path is segmented into multiple sections, each with independently calculated target conveyance times and target speeds. This segmentation allows the control system to optimize speed profiles for each section to prevent load swing, transitioning from a single-speed control approach to multi-section differential control.
2Manufacturing precision
If automated driving is implemented to convey load along a set path, then conveyance accuracy is improved, but load swing occurs during conveyance
Solution Approach 1:
The control apparatus calculates optimal target conveyance times and target speeds for each section before automated conveyance begins. By pre-planning the speed profile based on section characteristics, the system achieves both accurate path following and load swing prevention, eliminating the trade-off between conveyance accuracy and load stability.
Solution Approach 2:
The system dynamically adjusts target speeds for different sections of the conveyance path based on calculated target conveyance times. Rather than using a constant speed throughout, the control apparatus varies target speeds section by section to maintain load stability while achieving accurate conveyance, making the speed profile adaptive to path characteristics.
Data Source
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AI summary
The present invention addresses the problem of providing: a crane control method whereby shaking of a load can be suppressed when automatically transporting the load along a set transport path using a crane; and a crane that is controllable by this control method. The control method comprises: calculating a target transport time (Ti) of a load (W), transported by a crane (1), in a section defined by two passing points adjacent in a passing order; calculating, from a distance between the passing points and the target transport time (Ti), a target speed signal of the load (W) in the section; converting a stepped target speed signal, which connects the target speed signal of the section and a target speed signal of another section adjacent to the section, to a non-stepped target speed signal using a target value filter (F); and carrying out control on the basis of the non-stepped target speed signal.