Patent ID: 7484632

Claim:
A method for calculating a distance in which a crane is stopped, the method comprising: giving velocity requests as control sequences from a crane control system to crane drives and reading and storing the velocity requests (Vref) in a control system, each velocity request (Vref) is compared with the previous velocity request and, if the velocity request is changed, an acceleration sequence for the corresponding velocity change is formed and stored, after which, summing the velocity changes defined by stored acceleration sequences after a given time interval and adding the obtained sum (dV) to the previous velocity request to achieve a new velocity request (Vref 2 ), which is set as a new control and velocity request for the crane drives, and performing some of the velocity changes defined by the summed acceleration sequences at a definition time of each acceleration sequence and performing the rest of them as delayed, defining, at any given time, a distance (s) the crane moves before stopping and without swinging of the load fastened to it by summing up the following calculations: a) stopping distance (s 1 ), which is calculated on the basis of, a velocity at which the control of an algorithm implementing this ends, when the stored velocity changes are entirely implemented, by using a selected deceleration ramp, and b) a second distance (s 2 ), which is calculated on the basis of stored velocity change requests stated before a stopping decision, and on the basis of remaining performance times.