Bridgestone Corporation

Kazutomo Murakami

Yasuhiro Suzuki

Keiichiro Mizuno

Kazuyoshi Iida

Toshihiro Miyazaki

Nobuo Masaki

Hirokazu Watai

Yoji Suizu

Hirokazu Kudoh

Masanori Ooishi

A rotational signal of a generation source of a control object is detected and, when a rotational speed (frequency) varies, convergence values of filter coefficients of adaptive filtersbased on a previous control result corresponding to the frequency stored in a control deviceare retrieved and set to the adaptive filtersas initial values. The adaptive filtersare updated by using the initial values of filter coefficients and output a control signal y(t) to an ACM (actuator). LMS arithmetic unitsread a reference signal calculated from the rotational signal and an acceleration signal (error signal) e(t) detected by a sensorand carry out processing for updating the filter coefficients of the adaptive filters. The adaptive filters, based on updated filter coefficients, output the control signal y(t) to the ACM

Vehicle vibration reduction system

Acoustics or vibrations at a plurality of predetermined positions are respectively detected in the form of analog values, and the detected analog values are respectively converted into digital values. The digital values are subjected to digital filtering by using the digital values and filter factors, and at least one of the filter factors is changed such that the difference between the total sum of the results of digital filtering and a targeted value becomes minimum. The rate of contribution to an evaluation point is computed by using the results of digital filtering within a predetermined time when the difference becomes minimum, and the computed rate of contribution is displayed.

Method and apparatus for diagnosing sound source and sound vibration source

Disclosed is a vibration control method being largely effective in vibration-proof even when a natural frequency is relatively low and its transmissibility of vibration is high and being thus effective in reducing vibration in a wide range of frequencies; and its apparatus. In the above method, vibration information of a vibration source as a reference signal and vibration information of a vibration-proof object as an error signal are inputted into an adaptive filter. The reference signal is processed by regenerating a filter coefficient on the basis of adaptive algorithm, to form a feedforward signal. In the other hand, vibration information of the vibration-proof object is inputted in a feedback calculating means, and a feedback control signal is formed on the basis of a feedback control rule. The feedforward control signal and the feedback control signal are synthesized, to form a drive signal for a vibration exciting means. The vibration exciting means is thus controlled and driven on the basis of the drive signal.

Method and apparatus for controlling vibration

A vibration isolating device comprises a base, a plurality of support members each placed onto the base and comprised of a two series layer of an electroviscous body and an elastomeric body, and a cradle supported through these support members. These support members are provided with circuit for applying voltage to each electroviscous body, respectively.

Vibration isolating support device

A vibration damping apparatus for transportation includes a vertical direction damping device having air springs and air dampers arranged in parallel on a base and horizontal direction damping device having laminated rubbers. The vertical and horizontal damping devices are combined in series for supporting a load base. The apparatus further includes an air supply source for supplying air into the air springs, control valves provided between the air springs and the air supply source for controlling air supply into and exhaust from the air springs, displacement detecting device for detecting displacements of the load base relative to the bases, and control device for controlling the control valves on the basis of results detected by the displacement detecting device to maintain the load base horizontally and at a constant level relative to the base whatever load is loaded on the load base.

Vibration damping apparatus for transportation

A vibration control system for damping vibration of an body to be isolated against vibration. The body is supported on a movable base through the medium of vibration-damping supporting structure. The control system comprises a vibration sensor for detecting vibration of the movable base. An inverse vibration signal generating circuit includes a digital sensor and in supplied with a detection signal outputted from the vibration sensor for generating a signal with a waveform to cancel out the vibration of the body through interference therewith. An actuator is connected operatively to the movable base and the inverse vibration signal generating circuit for converting the signal derived from the latter into a mechanical vibration to be applied to the body.

Vibration control system

An oscillating apparatus comprises a cylinder, a piston reciprocatingly movably fitted in the cylinder, shaft members connected to the piston and extending out of the cylinder. The cylinder, piston and shaft members form an oscillator. An inlet and an outlet for an electro-rheological fluid are provided at each of two cylinder chambers defined in said cylinder by the piston. The apparatus further comprises voltage applying devices for applying electric voltage to the electro-rheological fluid passing through the inlets and outlets, respectively, so that applications of the voltage to the inlet of one cylinder chamber and the outlet of the other cylinder chamber are simultaneously effected and applications of the voltage to the inlets of both the cylinder chambers are alternately effected. With this arrangement, the switching-over of the closing and opening of the inlets and outlets are very rapidly performed by the application and removal of the electric voltage so that the piston undergoes vibration which is transmitted through the shaft members to an object, structure or the like, with the result that the object is controllingly vibrated and vibration to which the object is subjected is effectively damped.

Oscillating apparatus for damping vibration

Gear made of magnetic material is attached with permanent magnet on the web thereof for damping vibration and noise caused when gears are in operation.

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Yokohama, Japan

Kazutomo Murakami