Method of swing stopping control and system of swing stopping control of suspended load of crane

摘要

A method of swing stopping control of a suspended load of a crane including a hoist and a trolley solves an equation of motion, given as an equation with respect to the deviation angle of a suspended load from the vertical direction when the trolley travels, for the trolley acceleration to thereby obtain the value of the acceleration or deceleration of the trolley, obtains speed patterns corresponding to the values of the acceleration or deceleration, drives the trolley according to the obtained speed patterns, and carries out control so that the deviation angle of the suspended load from the vertical direction becomes zero at the time when the acceleration or deceleration of the trolley is ended. Thus, even if the length of a rope holding the suspended load up is changed, a required speed pattern is produced to permit highly accurate positioning.

主权项

1. A method of swing stopping control of a suspended load of a crane having a hoist carrying out lifting and lowering of a load suspended by a rope and a trolley traveling on a track while holding the suspended load up, the method comprising:
solving an equation of motion, given below as equation (1) with respect to a deviation angle of the suspended load from a vertical direction when the trolley travels, for acceleration of the trolley to thereby obtain a value of one of the acceleration and deceleration of the trolley given below by equation (2); obtaining speed patterns corresponding to values of the one of the acceleration and deceleration; driving the trolley according to the speed patterns, such that the trolley initiates deceleration when a positional deviation of an actual position of the trolley from a target position of the trolley is equal to a deceleration initiation distance; and carrying out control so that the deviation angle of the suspended load from the vertical direction is equal to zero at a time when the one of the acceleration and deceleration is ended:Lr·ⅆ2⁢θⅆt2+2·ⅆLrⅆt·ⅆθⅆt+g⁢⁢θ=-α(1) where Lr is a rope length, θ is the deviation angle of the suspended load from the vertical direction, g is gravitational acceleration and α is the one of the acceleration and deceleration of the trolley, andα⁡(t)=[Lrg⁢(2⁢π/Ts)2-1]⁢α⁢⁢k·cos⁡(2⁢πTs)⁢t+α⁢⁢k+αkg·2⁢⁢Vh·(2⁢πTs)·sin⁡(2⁢πTs)⁢t(2) where α(t) is the one of the acceleration and deceleration of the trolley, Lr is the rope length, g is the gravitational acceleration, Ts is a reference swinging period of the suspended load, αk is one of a reference acceleration and a reference deceleration of the trolley, Vh is a hoist speed and t is a time elapsed from the initiation of one of the acceleration and deceleration.