Abstract: A discrete Kalman filter 12 and a disturbance estimating unit 13 are added to a feedback loop for feeding back a detected value of position from a position detector 6. The Kalman filter estimates position and velocity of an object to be controlled, thereafter outputting an estimated value of position and an estimated value of velocity. The disturbance estimating unit estimates from a command value of current and the estimated value of velocity the disturbance that is added to a load 5. The estimated value of position is fed back to a position controller 1, and the estimated value of velocity is fed back to a velocity controller 2. Further, a difference between a target value of current outputted from the velocity controller and the estimated value of disturbance is output as the command value of current.

Abstract: A computation error of band-by-band bit allocation between an encoder and a decoder is prevented. On the encoder side, an input LSP coefficient is quantized by a quantization device, and a quantized output is output. In a codebook referring section, the look up of a codebook in which computation results are prestored is performed by using an LSP index of the first stage, and band-by-band bit allocation information is created. LSP indexes for each quantization stage are supplied to a decoder side. On the decoder side, the look up of the codebook is performed using the LSP index, and dequantization is performed on the basis of the created band-by-band bit allocation information.

Abstract: An apparatus and a method for encoding an input signal on the time base through orthogonal transform involves removing the correlation of signal waveform based on parameters obtained by linear predictive coding (LPC) analysis and pitch analysis of the input signal on the time base prior to the orthogonal transform. A normalization circuit section removes the correlation of the signal waveform and takes out the residue by an LPC inverse filter and pitch inverse filter and sends the residue to an orthogonal transform circuit section. The LPC parameters and the pitch parameters are sent to a bit allocation calculation circuit. A coefficient quantization section quantizes the coefficients from the orthogonal transform circuit section according to the number of allocated bits from the bit allocation calculation section.

Abstract: The small and light piezoelectric actuator of the present invention is capable of highly precisely positioning a magnetic head assemblies, etc. The piezoelectric actuator comprises: a movable member to which a head suspension is fixed; a fixed member fixed to a carriage arm; piezoelectric elements provided between the movable member and the fixed member and capable of adjusting a position of the head suspension by their deformation; and an electrode member electrically connected to one of electrodes of each of the piezoelectric elements. The movable member is adhered on the piezoelectric elements and electrically insulated from the other electrodes of the piezoelectric elements. The electric conductive layer of the electrode member and the other electrode of each of the piezoelectric elements are electrically connected to cables, which are provided to the head suspension so as to actuate the piezoelectric elements.

Abstract: An apparatus and method for performing transform encoding, in which time domain samples can overlap one another by any desired percentage and can be added so that signals may be reproduced completely. In the apparatus and method, the linear/nonlinear prediction analysis section 3 receives an audio signal from the input terminal 2 and effectuates linear or nonlinear prediction on the audio signal, generating a prediction residual. The constancy inferring section 7 infers the constancy of the audio signal. The block-length determining section 8 determines the length of an MDCT block from the constancy of the input signal, which the section 7 has inferred. The MDCT section 5 receives M time domain samples supplied from the buffer 4 and having the prediction residual. The MDCT section 5 applies the block length determined by the section 8, performing MDCT transform on the time domain samples, thus generating MDCT coefficients. The quantization section 6 quantizes the MDCT coefficients.

Abstract: First, at step Si, i=0 is set. At step S2, data comprising M samples is fetched. At step S3, an M-point DFT is applied to the data fetched at step S2 above. At step S4, an obtained y(k) is multiplied by a twist coefficient w(i, k). The result is placed in y(k). At step S5, the value in y(k) is overwritten to an array x which contains original data. The above processing is repeated N/M times through steps S6 and S7 until all the input data is processed. At step S9, an FFT with N/M (=2n) points is performed within the range of 0≦k<M. Finally, at step S12, a sort is performed.

Abstract: An apparatus and a method for encoding an input signal on the time base through orthogonal transform involves removing the correlation of signal waveform on the basis of the parameters obtained by means of linear predictive coding (LPC) analysis and pitch analysis of the input signal on the time base prior to the orthogonal transform. The time base input signal from input terminal is sent to a normalization circuit section and a LPC analysis circuit. The normalization circuit section removes the correlation of the signal waveform and takes out the residue by an LPC inverse filter and pitch inverse filter and sends the residue to an orthogonal transform circuit section. The LPC parameters from the LPC analysis circuit and the pitch parameters from the pitch analysis circuit are sent to a bit allocation calculation circuit.

Abstract: An apparatus and a method for encoding an input signal on the time base through orthogonal transform, comprising a step of removing the correlation of signal waveform on the basis of the parameters obtained by means of linear predictive coding (LPC) analysis and pitch analysis of the input signal on the time base prior to the orthogonal transform. The time base input signal from input terminal 10 is sent to normalization circuit section 11 and (LPC) analysis circuit 39. The normalization circuit section 11 removes the correlation of the signal waveform and takes out the residue by means of LPC inverse filter 12 and pitch inverse filter 13 and sends the residue to orthogonal transform circuit section 25. The LPC parameters from the lop analysis circuit 39 and the pitch parameters from the pitch analysis circuit 15 are sent to bit allocation calculation circuit 41.

Abstract: An apparatus and a method for encoding an input signal on the time base through orthogonal transform, comprising a step of removing the correlation of signal waveform on the basis of the parameters obtained by means of linear predictive coding (LPC) analysis and pitch analysis of the input signal on the time base prior to the orthogonal transform. The time base input signal from input terminal 10 is sent to normalization circuit section 11 and (LPC) analysis circuit 39. The normalization circuit section 11 removes the correlation of the signal waveform and takes out the residue by means of LPC inverse filter 12 and pitch inverse filter 13 and sends the residue to orthogonal transform circuit section 25. The LPC parameters from the lop analysis circuit 39 and the pitch parameters from the pitch analysis circuit 15 are sent to bit allocation calculation circuit 41.

Abstract: An optimum arrangement of position detectors which is inexpensive but hardly affected by intrinsic mechanical deflection or radial displacement on a rotary structure or motor and by a secondary artifact or variation i the magnetic coupling resulting from the mechanical deflection or radial displacement. A brushless DC motor with N phases (N≧2) according to the present invention is provided having position detectors of which signal outputs are indicative of the location of magnetic poles of a rotor and used for controlling the rotation for a constant speed. More particularly, it includes any two adjacent position detectors being spaced from each other by a spatial angle &thgr;i (rad) about the center of the rotor, (1/n)*(&thgr;i/2&pgr;)<KM is established where i=1 to N−1, 0<&thgr;i<2&pgr;/N, KM is the mechanical time constant of the motor (sec), and n is the number of revolutions (rps).

Abstract: A motor drive circuit is comprised of an H-bridge circuit which is formed of a flywheel diode and a switching device and connected to a motor coil; a current detecting circuit which is connected to the H-bridge circuit, has a plurality of shunt resistors, and computes a motor coil current value on the basis of voltage drops in the shunt resistors; a memory for storing an energizing direction of the motor coil and command value data regarding an energizing current waveform; a control circuit issues energizing current amount of the motor coil so that an error between command value data stored in the memory and a detected current signal detected by the current detecting circuit always stays zero; and a switching device driving logic circuit switches both source and sink of the H-bridge circuit when the motor coil is excited.

Abstract: An index signal is used for assuring media for use in a floppy disk drive to be exchangeable with each other. While the signal is output once for each rotation of a spindle motor, since the signal generation is carried out in a non-contact manner with rotating members including the medium, a hole sensor or the like has been previously used. However, such a hole sensor is expensive and fragile under temperature and mechanical stress. A pulse generator has been proposed, in which the rotor magnet is provided with magnets having unequally allocated angles and disposed all along a circumference and a stator coil and is disposed so as to match with the rotor magnet to have a pulse generated once for each rotation. However, the generated signal has, been poor in its S/N characteristic. It is an object of the invention to overcome the difficulties and provide a pulse generator that is highly reliable and excellent in the S/N characteristic with the manner of allocation of angles for the rotor magnet improved.

Abstract: In a two-phase, half-wave drive brushless motor or other dynamoelectric machine, a cogging torque reduction effect can be achieved without any reduction in motor output by reducing the number of auxiliary slots on the main pole surface or auxiliary pole surface and the number of winding slots provided between the main poles and the auxiliary poles.

Abstract: A two-phase unipolar drive type brushless DC motor has an armature including a stator yoke with salient poles around which coils are wound, and a rotor having a retainer with a rotor magnet which faces the armature at a predetermined small interval defined between the rotor magnet and the armature. The retainer is made of a polymeric material containing magnetic powder and formed integral with a rotor magnet. The rotor magnet is made of a highly efficient magnetic material or a rare earth magnetic material and consists of segment type permanent magnet pieces which are arranged circumferentially in the retainer. The motor is manufactured at a low cost and provides a stable magnetic wave form which can be used as a spindle motor in various kinds of memory apparatuses.

Abstract: A two-phase unipolar driving brushless DC motor of a radial gap type having a rotor position detector includes a main-pole yoke having main-poles, an interpole yoke coaxially provided with the main-pole yoke in a superposed manner and having interpoles and an axial short-circuit portion or member provided in an axially extending portion in magnetic fluxes formed in the main-poles and interpoles. This structure allows for easy winding of coils around the main-poles and enhanced winding space factor in order to increase the starting torque and to improve the motor efficiency.

Abstract: A pulse generator includes a rotor assembly which is formed by circularly arranged magnetic poles, and a stator assembly which is disposed coaxial with the rotor assembly and is formed by stator coils arranged circularly. Index angles defined by the circumferential ends of the magnetic poles are made unequal to each other. Pitches defined by angular intervals between adjacent stator coils are selected to allow the stator coils to electromagnetically match the corresponding magnet poles only once per revolution of the rotor assembly.