Crane Control System Using Input Shaping for Oscillation Damping
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Solution Overview
Problem
Conventional crane control systems face challenges in controlling payload oscillations due to response delays and require extensive training for operators to manage non-intuitive interfaces, leading to safety concerns and inefficiencies.
Innovation Solution
A crane control system incorporating a real-time position-location module, an on-off controller module, and an input shaper module, utilizing Ultra-Wide-Band RF signals to generate position signals and map them into velocity commands, which dampen payload oscillations by adjusting the crane trolley's velocity based on distance thresholds from a locator device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional crane control systems are used with push-button pendants or joysticks, then operators can control the crane trolley, but the response delay causes payload oscillations and requires extensive training
Solution Approach 1:
The patent replaces the mechanical control interface (push-button pendants, joysticks) with a wireless locator device that uses RF signals for communication. This substitution eliminates the need for operators to learn complex button sequences and directional mappings, while the real-time position feedback and automated control algorithms prevent payload oscillations by continuously adjusting the trolley position based on the locator device's location.
2Productivity
If operators use push-button pendants to control crane movement, then directional commands can be issued, but the non-intuitive interface requires extensive cognitive processing and training
Solution Approach 1:
The locator device serves as both the control input and the feedback mechanism. When an operator moves the locator device, the system automatically calculates the required trolley movement to maintain the desired offset position. The system self-adjusts without requiring the operator to understand complex control logic, making the interface intuitive and immediately productive.
Solution Approach 2:
The patent introduces a wireless locator device as an intermediary between the operator and the crane control system. This mediator translates the operator's simple positional movements into complex coordinated control commands for the trolley, eliminating the need for operators to directly manage multiple control functions and reducing interface complexity.
3Ease of operation
If the crane trolley moves to follow the locator device, then intuitive control is achieved, but payload oscillations occur during acceleration and deceleration
Solution Approach 1:
The system performs preliminary calculations of the required trolley acceleration and deceleration profiles before actual movement occurs. By pre-computing the optimal velocity profile based on the desired position change and current payload state, the system can execute movements that minimize oscillations from the start, rather than correcting them afterward.
Solution Approach 2:
The control system continuously updates the trolley position and velocity commands at high frequency, creating periodic control actions that counteract emerging oscillations. This rapid feedback loop allows the system to maintain intuitive control while actively damping payload oscillations through continuous small adjustments.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system simplifies crane operation, maintains safe distances, and effectively reduces payload oscillations during acceleration and deceleration, enhancing operator safety and operational efficiency by allowing intuitive control commands.
Implementation Method 1
utilizing Ultra-Wide-Band RF signals to generate position signals
Data Source
AI summary
The various embodiments of the present disclosure relate generally to crane control systems. An exemplary embodiment of the present invention provides a crane control system comprising a real-time position-location module, an on-off controller module, and an input-shaper module. The real-time position-location module generates a position signal indicative of the distance between crane trolley and a desired location of safety. The on-off controller module maps the position signal to a velocity command signal, wherein the velocity command signal comprises instructions for the crane trolley to move in a vector relative to the desired location in at least a first velocity only if the distance between the crane trolley and the desired location is greater than a cut-off threshold 150. The at least a first velocity is a substantially constant. The input shaper module manipulates the velocity command signal mapped by the on-off controller module to dampen payload oscillations.