Abstract: A pulse generating device includes a rotatable disc having a plurality of patterns that are formed on a surface of the rotatable disc in a circumferential direction of the rotatable disc, and three pulse generators to each detect the plurality of patterns formed on the rotatable disc and to respectively generate three pulse signals each corresponding to a rotational speed of the rotatable disc based on the detected patterns. The three pulse generators are evenly spaced at intervals of 120 degrees of angle with respect to a rotational axis of the rotatable disc in the circumferential direction of the rotatable disc.

Abstract: The stage device of the present invention includes a linear motor having a coil and a plurality of permanent magnets, a current driver that supplies current to the coil, and a control section that generates a command for the current driver. The control section generates the command through commutation processing in which a sinusoidal wave using an electrical angle obtained by calculation based on the relative position between the coil and the permanent magnet is multiplied by a thrust force command value for the linear motor, and further ensures that a sinusoidal wave component, which has an amplitude proportional to a thrust force command value and is 90 degrees out of phase from the sinusoidal wave, is included in the command.

Abstract: A voltage detection section and current detection section detect a voltage and current supplied to a motor, and the detected voltage and current are supplied to a position detection section. An angular speed output from the position detection section is supplied to a differentiator to output an angular acceleration. A fundamental wave component extraction section extracts a fundamental wave component of the angular acceleration, and the extracted fundamental wave component is supplied to an amplitude adjustment section. The output of the amplitude adjustment section is subtracted from the average current command by a subtraction section. This subtraction result, current detection value, and the rotor position from the position detection section are supplied to a current control section to carry out the current control operation so as to obtain a current command.

Abstract: The non-linear elastic deformation component included in the angular transmission error of an actuator provided with a wave gear drive is a component of the angular transmission error occurring due to elastic deformation of a flexible externally-toothed gear when the direction of rotation of the motor shaft changes. This component can be analyzed by driving the motor in a sine-wave shape. A model of the non-linear elastic deformation component (non-linear model) obtained from the analysis results is used to store data or a function for compensating for this component in a motor-control device. Compensation for the non-linear elastic deformation component (?Hys) is added to a motor-shaft angle command (?*M) as a compensation input (N?*TE) for feed-forward compensation. As a result, the non-linear elastic deformation component (?Hys) can be effectively reduced, and the positioning precision of the actuator can be improved.

Abstract: The stage device of the present invention includes a linear motor having a coil and a plurality of permanent magnets, a current driver that supplies current to the coil, and a control section that generates a command for the current driver. The control section generates the command through commutation processing in which a sinusoidal wave using an electrical angle obtained by calculation based on the relative position between the coil and the permanent magnet is multiplied by a thrust force command value for the linear motor, and further ensures that a sinusoidal wave component, which has an amplitude proportional to a thrust force command value and is 90 degrees out of phase from the sinusoidal wave, is included in the command.

Abstract: Three rotation sensors circumferentially arranged at 90 degree intervals in a disk code wheel attached to a motor's output shaft respectively output a signal corresponding the rotational speed of the wheel. An error component of one period (one-periodic component) or an error component of two period (two-periodic component) is generated per rotation when the code wheel is eccentric to the output shaft or is elliptically deformed, respectively. Control means averages the signals of the first and second sensors to obtain a first correction signal and subtracts the signal of the third sensor from the signal of the first sensor to obtain a second correction signal while removing the two-periodic component. The control means subtracts or adds the first correction signal relative to the second correction signal upon coinciding these signals in phase and amplitude to calculate a rotation measurement signal from which the periodic components are removed.

Abstract: The invention concerns a feed system control method and apparatus that can calculate an accurate backlash amount and can accomplish highly precise position control. Position errors are calculated before and after a reversal in direction of movement of a slide 30, each from the difference between the position data of the slide 30 detected by a linear scale 25 and the position data of the slide 30 calculated from the rotational position data of the servo motor 23 detected by a rotary encoder 24. The backlash amount of the slide 30 is calculated from the difference between the position error before the reversal and the position error after the reversal thus calculated. Thereafter, when reversing the direction of movement of the slide 30, the feed speed during direction reversal is increased in accordance with the backlash amount.

Abstract: A plurality of electromagnetics in an array surround a shaft, with current controlled in the coils of the electromagnets to support the shaft at a desired position approximately centered between the electromagnets. Shaft position sensors provide feedback to a control system for modulating the current to the electromagnet coils, which are arranged in pairs on opposite sides of the shaft. A drive circuit for each coil includes first and second switching transistors which connect the coil to the power supply to transfer a current pulse to the coil. A pair of circulating diodes begin conducting when the transistors turn off, and return power to the supply. A control circuit for the drive circuits interleaves on and off intervals for the coils in the electromagnet pairs so that one coil of the pair is being switched off at about the same time as the other coil of the pair is being switched on.

Abstract: In a machine which includes apparatus for feeding tape and for driving the tape feeding apparatus, there is provided an improvement for controlling the tape feeding apparatus. The improvement comprises the driving apparatus is provided with a d.c. motor having an output shaft for driving the tape feeding apparatus, and apparatus is provided for sensing angular displacement of the motor output shaft.

Abstract: The invention relates to an apparatus for compensating the output of a pendulous induction compass transmitter to eliminate heading errors during turns due to the vertical component of the Earth's magnetic field as well as those due to the horizontal component of the Earth's magnetic field perpendicular to the axis of tilt. By compensating for the effects of the Earth's vertical field component, instabilities and anomalies such as "Northerly Turning Error" are eliminated or minimized. Compensation for vertical field error is provided by generating a signal proportional to the product of the Earth's magnetic field M, the sine of the magnetic dip angle D at the given latitude and the sine of the aircraft tilt or bank angle .phi.. A compensating signal proportional to cos .phi. is generated and used to compensate for two cycle error.

Abstract: The invention relates to an apparatus for compensating a "strapdown" induction compass transmitter to eliminate heading errors during turns and during climbing and diving maneuvers which are due to the vertical component of the Earth's magnetic field and those due to the horizontal component of the Earth's field perpendicular to the axis of tilt. Instabilities and anomalies such as "Northerly Turning Error" which are due to the vertical component of the Earth's magnetic field are thus eliminated or minimized as is two cycle error which is due to the Earth's horizontal field during these same maneuvers. The vertical field roll compensating signal, to compensate for turn induced errors, is made proportional to the product of the Earth's magnetic field M, the sine of the dip angle D, and the sine of the bank or roll angle .phi.. The vertical field pitch compensating signal, to compensate for errors induced by climbing or diving maneuvers, is made proportional to the product of the sine of the angle .phi.

Abstract: The invention relates to an apparatus for compensating the output signals from a pendulous induction compass transmitter to eliminate heading errors during turns due to the vertical component of the Earth's magnetic field as well as those due to the horizontal component of the Earth's magnetic field perpendicular to the axis of tilt, i.e., two cycle error. By compensating for the effect of Earth's vertical field component, instabilities and anomalies such as "Northerly Turning Error" are eliminated or minimized. Compensation for vertical field error is achieved by generating a signal proportional to the product of the Earth's magnetic field M, the sine of the magnetic dip angle D at the given latitude and longitude and the sine of the aircraft bank or roll angle .phi.. This signal is combined (by summation) with the demodulated signal from the sin .psi. channel (i.e., the signal from the windings of the compass transmitter which senses the field along the athwartships axis) to cancel vertical error.

Abstract: The invention relates to an apparatus for compensating a "strapdown" induction compass transmitter to eliminate heading errors during turns, and during climbing and diving maneuvers which are due to the vertical component of the Earth's magnetic field as well as those due to the horizontal component of the Earth's magnetic field perpendicular to the axis of tilt. Instabilities and anomalies such as "Northerly Turning Error" which are due to the vertical field are thus eliminated or minimized as is two cycle error which is due to the Earth's horizontal field during these same maneuvers. The vertical field compensating signal during turns is proportional to the product of the Earth's magnetic field, M the sine of the dip angle D and the sine of the bank or roll angle .phi.. The vertical field pitch compensating signal while climbing or diving is proportional to the product of the sine of the pitch angle .theta., the Earth's magnetic field M and the sine of the magnetic dip angle D.