Abstract: In a quadruple loop position control device (1) including: a drive controller (5) having a current control loop that controls motor current (I) and a motor speed control loop that controls a motor speed (Vm); a speed control loop (3) that controls a speed (Vd) of a driven body (2); and a position control loop (4) that controls a position (Pd) of the driven body (2), an adder (6) that adds an output value from the position control loop (4) and an output value from the speed control loop (3) and inputs an addition result to the motor speed control loop is provided. By providing the adder (6), the position control device (1) functions as a control device of a first-order system, so that occurrence of an overshoot may securely be avoided even when respective transfer functions of the position control device (1) are set for purpose of suppressing a vibrating behavior of the driven body (2).

Abstract: A control device includes a first switch (400) by which an input signal to a motor speed control loop (910) is selected from a signal of a position control loop (300) and a signal of the speed control loop (200), and a switch controller (500) that controls switching of the first switch (400), so that the first switch (400) can switch between a quadruple loop (a current control loop, the motor speed control loop, the speed control loop (200) and the position control loop (300)) with the speed control loop (200) embedded therein, and a triple loop (the current control loop, the motor speed control loop and the position control loop (300)) without the speed control loop (200), corresponding to a transient state and a steady state.

Abstract: Two all pass filters (11, 12) with 90° phase-shifted different center frequencies are employed to pass an alternating signal S with jitters in the period to generate signals S1 and S2, 90° phase-shifted from each other. A pulse generator (22) generates a sampling pulse Sp by detecting a zero cross point of the phase-shifted signal S2. A full-wave rectifier (21) rectifies full waves of the phase-shifted signal S1 and provides a rectified output to a sampling circuit (23), which extracts a peak value of the amplitude at the timing of the sampling pulse Sp.

Abstract: An interference optical system (1) is employed to split an input light beam in two, giving a predetermined optical path length difference to the resultant two light beams and thereafter synthesizing them to generate interference fringes. A reference light with a known wavelength &lgr;1 is introduced into the interference optical system (1) from a coherent reference light source (2). A test light with an unknown wavelength &lgr;2 is simultaneously introduced into the interference optical system (1) from a coherent test light source (3) via a different optical path. The interference optical system (1) modulates both received signals obtained from the reference and test lights by giving the same variation to optical path length differences for the reference and test lights. Degrees of modulations of the received signals, obtained from the reference and test lights, depend on their wavelengths &lgr;1 and &lgr;2, respectively.

Abstract: A vibration change is detected by a touch signal probe having a vibrator (16) composed of a stylus support (10) and a stylus (13) attached thereto, and a vibrating/detecting means (12) provided to the stylus support (10) for applying vibration to the vibrator (16) and detecting a vibration condition changing when the stylus (13) touches a workpiece. The vibrator (16) is vibrated at a frequency equivalent to secondary intrinsic frequency (w2) to make resonance and the vibration change is detected by superposing a vibration component of primary intrinsic frequency (w1). Though the vibration at the secondary intrinsic frequency (w2) has high Q value, response amplitude is small. Accordingly, the vibration change is amplified by superposing the vibration component of the primary intrinsic frequency (w1).

Abstract: Two all pass filers (11, 12) with 90° phase-shifted different center frequencies are employed to pass an alternating signal S with jitters in the period to generate signals, S1 and S2, 90° phase-shifted from each other. A pulse generator (22) generates a sampling pulse Sp by detecting a zero cross point of the phase-shifted signal S2. A full-wave rectifier (21) rectifies full waves of the phase-shifted signal S1 and provides a rectified output to a sampling circuit (23), which extracts a peak value of the amplitude at the timing of the sampling pulse Sp.

Abstract: A stylus has a piezoelectric element support part to support and fix piezoelectric elements. The piezoelectric element support part is a regular polygonal body and its cross section orthogonal to the axis of the stylus is made a regular polygon. The piezoelectric elements are mounted on each side surface of the regular polygonal body, respectively. Sums and difference signals outputted from the piezoelectric elements are produced and a touch detection signal is generated based on the produced signals.

Abstract: In a measuring method with a probe (a touch trigger probe 70), a velocity V1 and a coordinate value P1 of the prove trigger probe 70 are detected when a contact-detection signal is generated from the probe 70, and then a coordinate value P0 at the moment of contact is found from the coordinate value P1, the velocity V1, and an elapsed time T1 of the touch trigger prove 70 since the contact detection (an elapsed time from the contact until the contact-detection signal is generated).

Abstract: The DC sensor signal S, on which a low frequency waviness component S1 and a high frequency noise component S2, is obtained by amplitude detecting for a sinusoidal output signal from a touch signal probe. For generating a touch trigger signal TG at an sbrupt DC level transition of the DC sensor signal S, the signal S is input to a LPF 21 to output a signal (S0+S1), where S0 is a DC offset component, and S1 is a low frequency waviness component. The amplitude transforming circuit 22 multiplies the signal (S0+S1) by a coefficient k to generate a reference signal k(S0+S1). The comparator 23 compares the DC sensor signal S with the reference signal to output the touch trigger signal TG at the abrupt DC transition point of the DC sensor signal S.

Abstract: The phase controlling circuit 1 controls the phase of the input sinusoidal signal S1 to generate first and second sinusoidal signal S1 and S2 which have different phases of 90.degree. shifted from each other. The signal generating circuits 2a and 2b square the first and second sinusoidal signal S1 and S2 to generate first and second squared sinusoidal signals S1.sup.2 and S2.sup.2, respectively. The squared sinusoidal signals S1.sup.2 and S2.sup.2 are added by the signal adding circuit 3, thereby generating the added output S3 which is an amplitude of the input sinusoidal signal S. The phase controlling circuit 1 comprises 90.degree. phase shift circuits 11 and 12 which have a common signal input terminal and the respective signal output terminals. The 90.degree. phase shift circuit is composed of an all-pass filter whose central frequency is set to be f0-.DELTA. f so as to generate the first sinusoidal signal. The second 90.degree.