Abstract: This invention provides a device for preventing sway of a suspended load, which does not require complex calculation for eliminating frictional resistance components. The device is equipped with a speed control device (14) for outputting a torque command based on a speed command, a torque command filter (16), and a load torque observer (4) for estimating the load torque, and configured to output a value obtained by adding a load torque estimation signal to an output of the torque command filter (16). The device is further equipped with a high-pass filter (32) for outputting a signal TRFLHPF in which a frictional resistance component is eliminated from the load torque estimation signal and a sway angle calculator (33) for outputting a sway angle estimation calculated value ?e obtained by multiplying a sway angle calculator factor by the output signal TRFLHPF.

Abstract: This invention provides a device for preventing sway of a suspended load, which does not require complex calculation for eliminating frictional resistance components. The device is equipped with a speed control device (14) for outputting a torque command based on a speed command, a torque command filter (16), and a load torque observer (4) for estimating the load torque, and configured to output a value obtained by adding a load torque estimation signal to an output of the torque command filter (16). The device is further equipped with a high-pass filter (32) for outputting a signal TRFLHPF in which a frictional resistance component is eliminated from the load torque estimation signal and a sway angle calculator (33) for outputting a sway angle estimation calculated value ?e obtained by multiplying a sway angle calculator factor by the output signal TRFLHPF.

Abstract: It is an object of the invention to provide a torsional vibration suppressing apparatus further including an inertia control portion capable of suppressing a feeble vibration in a torsional vibration suppressing control portion.

Abstract: It is an object of the invention to provide a torsional vibration suppressing apparatus further including an inertia control portion capable of suppressing a feeble vibration in a torsional vibration suppressing control portion.

Abstract: A control system which stabilizes the hoisting rope of a suspension crane comprising a travel drive control unit capable of calculating a torque reference signal by a speed regulating controller having a proportional gain and an integrator or only a proportional gain on the basis of the deviation of a speed detection signal representing the rotating speed of a traveling motor for driving the trolley of the crane from a speed reference signal obtained by subtracting a damping control speed reference correction signal which is obtained by adding a damping factor to a swing angle calculated on the basis of the speed detection signal representing the rotating speed of the traveling motor or a calculated load torque on the traveling motor from a speed reference signal provided through a linear acceleration starter device by a speed reference device, of controlling the rotating speed of the traveling motor according to the torque reference signal, and of producing a damping effect for damping the oscillation of the

Abstract: Herein disclosed are a method and an apparatus for suppressing a torsional vibration in an electric motor speed control system including a mechanism for transmitting a drive torque from an electric motor to a load through a drive shaft having a torsional spring system. Generally speaking, the signal of a speed detector (3) of an electric motor is a pulsating signal of high frequency. Even if this speed detecting signal is differentiated, it is impossible to obtain a signal proportional to the changing rate of the motor speed. By computing an average value of the signals of the motor speed detector (3) for every predetermined period, however, the pulsating value of the speed signal can be reduced to compute the changing rate of the motor speed from that signal.