Harmonic Drive Systems Inc.

Junji Koyama

Kunio Miyashita

Muneo Mitamura

Hiroshi Kameda

Yasuo Sawamura

Masakatsu Sasahara

Teizo Morimoto

Kazuhiro Kosuge

Naoki Kanayama

Kiyoto Kobayashi

Yasuhisa Hirata

Yoshitomo Mizoguchi

Shunichi Tezuka

Toshiaki Kamata

Makoto Shimojo

Syunichi Tezuka

Junya Ichinose

A complex sensor comprises a touch sensor and a proximity sensor. The touch sensor comprises a flexible pressure-sensitive sheet covering a fingertip portion. The pressure-sensitive sheet comprises a front surface film and a rear surface film composed of a flexible conductive material, an intermediate film which is sandwiched between the films in a state in which the intermediate film is electrically connected and which is composed of pressure-sensitive conductive rubber, and first to fourth electrode terminals formed on the front surface and rear surface films. The size of a load acting on the pressure-sensitive sheet and the center position of the load can be detected based on the terminal voltage. A through-hole is formed in the pressure-sensitive sheet such that the sensing surface of the proximity sensor is exposed, thus the approach of a holding object can be detected.

Complex sensor and robot hand

A magnetic encoder includes a multi-pole magnetic detecting unit having a multi-pole magnet. In the multi-pole magnetic detecting unit, first and second magnetic detecting elements that output sinusoidal signals having a 90&#xb0; phase difference are arranged apart from third and fourth magnetic detecting elements at a mechanical angle of 180&#xb0; . The first and third magnetic detecting elements are disposed at the same position represented by an electrical angle and output sinusoidal signals of a same phase. The second and fourth magnetic detecting elements are arranged at the same position represented by an electrical angle and output sinusoidal signals of a same phase. A sum signal of the output signals of the first and third magnetic detecting elements and that of the output signals of the second and fourth magnetic detecting elements are obtained, thereby eliminating or remarkably reducing error components of detection signals of the first to fourth magnetic detecting elements caused by the magnetic flux of a two-pole magnet and those of the detection signals caused by rotational run out of the multi-pole magnet. A rotational angle can be detected with high accuracy.

Magnetic encoder and method of detecting absolute rotational position

When dishes are held by means of a robot hand (), its fixed side engaging plate () and movable side engaging finger () are moved under horizontal state toward a dish () to be handled, and the outer circumferential edge side portion of the dish () is inserted between them. The distal end portion () of the movable side engaging finger () is then bent by a predetermined amount to the side of the dish () and the robot hand () is raised. Consequently, the dish () is brought into a state where it is held by its own weight between the fixed side engaging plate () and the movable side engaging finger (). Thereafter, the right and left first finger units () are bent to the side of the dish () and the dish () is pushed by their dish pushing faces (), thus bringing about such a state as the dish () is held surely between the fixed side engaging plate () and the movable side engaging finger ().

Robot hand and method for handling planar article

A magnetic absolute sensor for a geared motor comprises a dipole magnet and hall elements. The dipole magnet is fixed to a hollow portion of a hollow rotor shaft. A bracket attached to an end plate of a motor housing is coaxially inserted from the rear end side of the hollow portion. The dipole magnet is inserted from the front side in a cylindrical portion of the bracket. The hall elements are arranged at an interval of 90 degree on the circular inner periphery surface of the cylindrical portion. The hall elements face the circular outer periphery surface of the dipole magnet with a fixed gap therebetween. It is not necessary to increase a motor shaft length in order to incorporate the magnetic absolute sensor. The flux of a motor driven magnet is blocked by the hollow rotor shaft and the hall elements are not adversely affected.

Apparatus for detecting position of rotation of motor

A multiple-rotation absolute-value encoder of a geared motor, wherein the geared motor () reduces the rotational speed of a motor shaft () and takes it out from a gear shaft () to drive a machine device () in an operating range corresponding to two rotations of the gear shaft (). The multiple-rotation absolute-value encoder () fitted to the geared motor () is made up of a gear shaft absolute value encoder () for detecting the absolute position of the gear shaft () and a load side absolute value encoder () having a two-pole magnet () and a magnetic sensor () rotating at a rotational speed reduced to half the rotational speed of the gear shaft () through the magnetic gear ().

Multiple-rotation absolute-value encoder of geared motor

A finger joint mechanism () having two wave gear reduction drives () disposed coaxially with each other, in which rotational force of a motor () is transmitted to a rotation input shaft () common to the drive gears through a driving bevel gear () and a driven bevel gear (). Output shafts () are formed integrally with bosses () of the cup-like flexible external gears () of the wave gear drives (), and mounting arms () of a rotating member () are fixedly connected to the output shafts. The wave gear reduction drives, which can be easily reduced in size, are used as the reduction gears for a rotary actuator () assembled in the finger joint mechanism. Since the finger joint mechanism uses the two wave gear reduction drives, the rate of increase in torque capacity against the rate of increase in an installation space is much higher than a case where one gear reduction drive with a large model number is used to increase torque capacity of the mechanism.

Finger joint mechanism

A rotary terminal mechanism in which a first electroconductive ring is inserted, under a slightly collapsed state, between the circular internal peripheral surface of a first outside electrode and the circular external peripheral surface of a first inside electrode that are arranged concentrically. The first electroconductive ring is kept contacting the first outside electrode and the first inside electrode by the elastic restoring force. When the first outside electrode and the first inside electrode rotate relatively, the first electroconductive ring rolls along the circular internal peripheral surface and the circular external peripheral surface while being kept pressed against these surfaces by the elastic force. Consequently, electrical connection is formed constantly between them even if the first outside electrode and the first inside electrode rotate relatively. A rotary terminal mechanism of simple structure requiring fewer components and being advantageous to miniaturization can thereby be attained.

Rotary terminal mechanism

A multi-finger grasping mechanism (), comprising three two-joint finger units (-to-). Each two-joint finger unit further comprises a finger root part (), a finger root side joint part (), a finger intermediate part (), a finger tip side joint part (), and a finger tip part (). The finger intermediate part () can be swung about the joint axis () of the finger root side joint part (), and the finger tip part () can be swung about the joint axis () of the finger tip side joint part (). The finger tip part () can be swung about the center axis thereof. When a bolt (W) is held by the finger tip part () and the finger part () is rotated, the tightening operation of the bolt (W) can be performed.

Finger unit and multi-finger grasping mechanism

An insert member () having an identical permeability is fitted in the circular center hole() of a magnetic ring () which is then fitted in the circular hollow section () of a fitting-over member () having an identical permeability. Under that state, the magnetic ring () is placed in a parallel magnetic field. Lines of magnetic flux passing through the magnetic ring () held between the insert member () and the fitting-over member () become linear without substantially inclining against the parallel magnetic field. Under that state, harmonic noise causing a deterioration in detection precision will scarcely appear in the output of a magnetic sensor for detecting the rotating magnetic field of a ring magnet () obtained by performing two-pole magnetization on the magnetic ring (). When the ring magnet () is employed, a deterioration in the detection precision of a magnetic encoder () due to the magnetization state of the ring magnet () can be avoided, and the deterioration in detection precision can be suppressed.

Method for magnetizing ring magnet and magnetic encoder

A joint mechanism that can be used in an articulated finger unit of a robot hand has first and second actuators that are disposed facing each other from the front and back on either side of a perpendicular joint axle, and first and second drive bevel gears that are coaxially connected and fixed to distal ends of output axles thereof. A driven bevel gear fixedly mounted in coaxial manner on the perpendicular joint axle meshes with the first and second drive bevel gears. The perpendicular joint axle is rotatably driven by the two actuators, and a revolving bracket connected thereto revolves to the left and right. The drive torque of the joint axle can be increased without increasing the outside diameter dimensions of the mechanism.

Joint mechanism for robot hand and the like

In the multi-shaft driving apparatus, position command pulse trains for servomotors are generated from a motor controller and supplied to motor drivers for the respective servomotors via a multichannel pulse train transmitting apparatus. The multichannel pulse train transmitting apparatus converts the position command pulse trains supplied from the motor controllerto serial signals in a transmission-side converter, combines the resulting serial signals as a stream signal, and supplies the signal to a reception-side converter via a serial signal transmission path composed of a pair of signal wires. In the reception-side converter, motor position command pulse trains in the form of a serial signal is returned to multichannel pulse trains in the form of a parallel signal which are supplied to the motor drivers. The number of wires between the motor controller and the motor drivers can be reduced.

Multichannel pulse train transmitting apparatus

A motor encoder is mounted on a motor shaft of a geared motor, and the origin position is detected by using a Z-phase signal. An absolute value encoder with a precision that allows the number of motor rotations to be determined is mounted on an output shaftof a reduction gear, and the absolute rotational position thereof is detected. When the first Z-phase signal generated in conjunction with the rotation of the motor shaftis obtained at startup and at other times, the mechanical starting point at which the motor shaft and output shaft are both positioned at the origin can be calculated based on the absolute rotational position of the reduction-gear output shaft obtained from the output-side absolute value encoder. Since the mechanical starting point is obtained by rotating the motor shaft a single rotation at most, the time required to calculate the mechanical starting point is short in comparison with conventional examples, and extraneous rotational movements can be avoided.

Geared motor

An encoder mounted on a motor axle of an AC servomotor has a single bipolarly magnetized rotational disk, magnetic sensors for outputting X- and Y-signals that differ in phase by 90&#xb0; in association with the rotation thereof, and a signal processing unit. The signal processing unit computes at predetermined cycles a rotor angle &#x3b8;a of a motor rotor on the basis of the X- and Y-phase signals, generates three-phase magnetic pole signals U, V, and W that differ in phase by 120&#xb0; on the basis of the number M of magnetic poles of a motor, a magnetic pole reference angle &#x3b8;o, and the rotor angle &#x3b8;a; and generates A- and B-phase signals with predetermined pulse cycles that differ in phase by 90&#xb0; on the basis of the rotor angle &#x3b8;a. An encoder that is advantageous for reducing the size and weight of an AC servomotor can be realized because it is sufficient to provide a single assembly composed of a rotational disk and magnetic sensors.

Motor encoder

An articulated finger unit has a two-jointed structure comprising a joint portion on a finger base side, a finger base portion, a joint portion on a fingertip side, and a fingertip portion; the joint portion on the finger base side has a drive-side bevel gear fixed to a rotational output shaft of an actuator, a driven-side bevel gear coaxially fixed to a joint portion that is perpendicular to the rotational output shaft, and a connecting member wherein an annular boss is fixed to the driven-side bevel gear and wherein a tip portion extends in a fork shape; and a cover on the finger base side is connected to the connecting member. A rotation of the rotational output shaft is converted to rotational movement of the joint shaft by way of a pair of bevel gears, and the connecting member fixed to the joint shaft turns right and left at an angle of 90&#xb0; or more about the joint shaft. The finger unit suitable for use in a robot hand that moves at high speed and with precision can be realized.

Finger unit for robot hand

A palm mechanism for a high-speed robot hand has a fixed-side articulated finger unit that projects forward from an upper side of a vertically positioned palm plate, and moveable-side articulated finger units disposed on both sides thereof. The left and right articulated finger units are capable of turning along two short sides of the rectangular palm plate from upper end positions on the palm mechanism. The articulated finger units are capable of bending up and down about joint portions thereof. A variety of operations, including gripping, picking, and throwing, can be performed rapidly and reliably by controlling relative positions of the three articulated finger units and controlling bending operations of the articulated finger units.

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Azumino, Japan

Junji Koyama