Slewing Apparatus Angular Velocity Pattern for Load Swing
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Solution Overview
Problem
Existing slewing apparatuses that suspend loads from the tip of a boom face challenges in shortening slewing time while effectively suppressing swing of the suspended load, as conventional methods require acceleration and deceleration intervals equal to or longer than the swing cycle of the load.
Innovation Solution
A slewing apparatus with a control section that determines and implements a slewing angular velocity pattern with accelerated and decelerated intervals shorter than the pendulum cycle of the suspended load, allowing the boom to move at varying velocities to reduce slewing time while minimizing swing at the end position, using a combination of derricking and telescopic actuators to control the boom's movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the acceleration interval and deceleration interval are set equal to or longer than the swing cycle of the suspended load, then the swing of the suspended load is suppressed, but the slewing time from the slewing start position to the slewing end position increases
Solution Approach 1:
The patent applies dynamics by making the slewing angular velocity pattern variable and adaptive. The control section dynamically adjusts the angular velocity profile based on real-time parameters including pendulum length, slewing radius, and swing angles. This allows the system to optimize the balance between swing suppression and slewing time by continuously adapting the velocity pattern rather than using fixed intervals, thereby reducing slewing time while maintaining effective swing control.
Solution Approach 2:
The patent implements parameter changes by modifying multiple key parameters simultaneously: pendulum length (l), slewing radius (r), gravitational acceleration (g), and angular velocity (ω). The control section calculates optimal angular velocity patterns by varying these parameters to minimize slewing time while ensuring swing suppression. The system changes the relationship between acceleration/deceleration intervals and pendulum cycle dynamically based on calculated optimal values, breaking the conventional constraint that intervals must equal or exceed the swing cycle.
2Reliability
If the acceleration interval and deceleration interval are set equal to or longer than the swing cycle of the suspended load, then the swing of the suspended load is suppressed, but the operational efficiency decreases
Solution Approach 1:
The patent employs feedback mechanisms where the control section continuously monitors slewing angle, angular velocity, pendulum length, and swing angle of the suspended load. Based on this feedback, the system recalculates and adjusts the optimal angular velocity pattern in real-time. This closed-loop control enables the system to achieve swing suppression with shorter intervals, thereby improving operational efficiency without compromising reliability.
Solution Approach 2:
The control section performs preliminary calculations of the optimal angular velocity pattern before executing the slewing operation. By pre-calculating the optimal parameters including pendulum length, slewing radius, and gravitational acceleration, the system prepares an optimized velocity profile that minimizes slewing time while ensuring swing suppression, thus improving operational efficiency from the outset.
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
This approach effectively suppresses swing in both the slewing direction and radial direction of the suspended load, enabling a reduction in slewing time without increasing the cycle duration, thus improving operational efficiency.
Implementation Method 1
a pendulum length that is a length from the tip portion of the boom to a suspended load suspended from the hook
Implementation Method 2
a pendulum length that is a length from the tip portion of the boom to a suspended load suspended from the hook
Data Source
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AI summary
[Problem] To provide a pivoting device that can control swinging of a suspended load and can reduce the pivot time. [Solution] A pivoting device implements: an acquisition process to acquire a pivot start position, a pivot end position, and a pendulum length; a pivoting angular velocity pattern determination process to determine, by way of optimal control, a pivoting angular velocity pattern in a first interval to reach a pivoting angular velocity ω by accelerating, decelerating, and accelerating from the pivot start position and in a second interval to stop at the pivot end position by decelerating, accelerating, and decelerating from the pivoting angular velocity ω; and an actuator control process to cause a pivot actuator to pivot the pivoting body so that the distal end of a boom moves in the pivot direction at a speed indicated by the pivoting angular velocity pattern. In addition, during the pivoting angular velocity determination process, the pivoting device determines a pivoting angular velocity pattern for which the difference between the local maximum angular velocity and the local minimum angular velocity is larger for shorter control times T during the first interval and the second interval with control times T shorter than the cycle determined by the pendulum length of the suspended load to be moved as a pendulum.