Abstract: An objective is to obtain a high robust position controller and a controlling method therefor, with respect to their technique in which control gain, in order to prevent an overshoot due to frictions, is most suitably adjusted. The position controller having a feedforward system includes: a friction-coefficient-estimated-value setting unit for setting arbitrary friction-coefficient-estimated-values; an overshoot-prevention-gain calculator for determining speed-integral-term feedforward gain, based on estimated friction-coefficient values set by the friction-coefficient-estimated-value setting unit; and a speed feedforward multiplying unit for calculating the product of the speed-integral-term feedforward gain multiplied by a feedforward command value that is based on a positional command; the multiplication product from the speed feedforward multiplying unit being used to reduce the feedforward term.

Abstract: In a servo controller according to the invention, a position feedback correction unit (3) calculates a first-axis position feedback signal (pmfb1) based on a first-axis position (pm1) as a self-axis position, and a second-axis position (pm2) as an other-axis position; and a deviation between a model position (pal) and the first-axis position feedback signal (pmfb1) is inputted from a subtracter (5) to a position control unit (4), which performs positional control to output a velocity command. A velocity feedback correction unit (6) calculates a first-axis velocity feedback signal (wmfb1) from a first-axis velocity (wm1) as the self-axis velocity, and a second-axis velocity (wm2) as the other-axis velocity; and the velocity control unit (8) adds a model velocity (wa1) and the velocity command outputted from the position control unit (5), and subtracts the first-axis velocity feedback signal (wmfb1) therefrom, and outputs a feedback torque command (Tfb1) based on the corrected velocity command.

Abstract: A control device for an induction motor controlling torque generation of the induction motor with high precision includes a rotation speed detector which detects the rotation speed of the induction motor, a current detector which detects a primary current of the induction motor; an amplifying unit which amplifies deviation between an estimated primary current obtained from a magnetic flux observing device and the primary current obtained from the current detector; a magnetic flux observing device which estimates an estimated secondary magnetic flux and an estimated primary current of the induction motor based upon the rotation speed obtained from the rotation speed detector, the primary voltage of the induction motor and the deviation signal obtained from the amplifying unit, and a control unit which controls a voltage applied to the induction motor based upon the estimated secondary magnetic flux obtained from the magnetic flux observing device.

Abstract: The present invention provides a variable-speed control system which is capable of estimating saturation voltages of respective switching elements in the inverter operation to execute the saturation voltage compensation and thus getting an inverter output voltage indicated by a command value.

Abstract: An acceleration signal generating portion 11 inputs a machine velocity vm of a drive machine 32 and outputs an acceleration signal af of low frequency. Also, a pseudo torque signal generating portion 12 inputs a torque command &tgr;r, removes the noise, and outputs a pseudo torque signal &tgr;f of low frequency. Also, a torque error signal calculating portion 14 subtracts a product of the acceleration signal af and a previous mechanical constant estimated value Je(k−1) calculated in a multiplication circuit 13 from the pseudo torque signal &tgr;f of low frequency, and outputs a torque error signal &tgr;err as a disturbance torque estimated value &tgr;d0. Also, a mechanical constant estimation gain portion 16 estimates the mechanical constant by inputting a torque error derivative signal d&tgr;err that is generated by torque error derivative signal generating portion 15 by inputting a torque error signal &tgr;err.

Abstract: An acceleration signal generating portion 11 inputs a machine velocity vm of a drive machine 32 and outputs an acceleration signal af of low frequency. Also, a pseudo torque signal generating portion 12 inputs a torque command &tgr;r, removes the noise, and outputs a pseudo torque signal &tgr;f of low frequency. Also, a torque error signal calculating portion 14 subtracts a product of the acceleration signal af and a previous mechanical constant estimated value Je(k−1) calculated in a multiplication circuit 13 from the pseudo torque signal &tgr;f of low frequency, and outputs a torque error signal &tgr;err as a disturbance torque estimated value &tgr;d0. Also, a mechanical constant estimation gain portion 16 estimates the mechanical constant by inputting a torque error derivative signal d&tgr;err that is generated by torque error derivative signal generating portion 15 by inputting a torque error signal &tgr;err.

Abstract: The present invention provides a variable-speed control system which is capable of estimating saturation voltages of respective switching elements in the inverter operation to execute the saturation voltage compensation and thus getting an inverter output voltage indicated by a command value.