CPC B66C 13/105 (2013.01) [B66C 13/22 (2013.01); B66C 13/46 (2013.01); B66C 2700/088 (2013.01)] | 3 Claims |
1. A crane comprising:
a boom;
an actuator of the boom;
control circuitry configured to control the actuator of the boom based on a target speed signal indicating a moving direction and a speed of a load suspended from the boom by a wire rope and a suspending tool, and thereby drive the boom and move the load; and
an acceleration sensor configured to detect an acceleration of the suspending tool or the load, wherein
the control circuitry is configured to:
convert, every predetermined unit time, the target speed signal into a target position of the load relative to a reference position;
compute, every unit time, a current position of a boom tip relative to the reference position from a swivel angle, a luffing angle and an extension/retraction length of the boom;
compute, every unit time, a spring constant of the wire rope from a previously-computed position of the load the unit time before, the current position of the boom tip relative to the reference position and a current acceleration of the suspending tool or the load, the current acceleration of the suspending tool or the load being detected by the acceleration sensor every unit time;
compute, every unit time, a target position of the boom tip for the target position of the load from the current acceleration of the suspending tool or the load, the spring constant of the wire rope, and the target position of the load;
generate, every unit time, an operation signal for the actuator based on the target position of the boom tip; and
control the actuator in accordance with the operation signal.
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