Abstract: A compound drive mechanism (30) according to the invention is capable of driving an output element (10, 40) of an industrial robot for a linear motion along an axis and of rotating the output element (10, 40) independently of the linear motion of the output element (10, 40). The mechanism includes a linear-motion drive motor (M.sub.1) for driving the output element (10, 40) for linear motion, a rotation drive motor (M.sub.2) for driving the output element (10, 40) for a rotational motion arranged at a fixed position, a linear motion transmitting system (12 and 14; 42 and 44) for transmitting a linear motion to the output element (10, 40) a rotational motion transmitting system (18 and 20; 48 and 50) for transmitting a rotational motion to the output element (10, 40), and a rolling contact bearing (18, 46) interconnecting the linear motion transmitting means (12 and 14; 42 and 44) the rotational motion transmitting means (18 and 20; 48 and 50) to thereby obviate interference between those transmission systems.

Abstract: A sliding mode control method with a feedforward compensation function achieves a control response characteristic adapted to varying system parameters and properly maintains a manipulated variable affecting a controlled object. A position deviation (.epsilon.), speed deviation (.epsilon.), predicted maximum and minimum inertias (Jmax, J0), predicted maximum and minimum gravity loads (GRmax, GRmin), switching variable (s), integral element (.intg.(.epsilon.+C.multidot..epsilon.)), second differential (.theta.r) of the command position, and actual speed (.theta.) are periodically calculated on the basis of a command position (.theta.r), actual position (.theta.), inertia data, and gravity load data (100-102, 104, 107, 110, 114, 117, 120, 123, 127).

Abstract: The feedback gain for motor control for a control system in which the inertia of a load is greatly variable is adjusted. First, a feedback gain (K1) is determined. The value of feedback gain is calculated from a servomotor itself or the like, and selected so that the control loop will not oscillate (S1). A feed-forward gain (K) is determined according to a learning process with the feedback gain (K1) (S2). Then, a feedback gain (K1) is calculated from the feed-forward gain (K) (S3). Thereafter, a feed-forward gain (K) is determined again according to a learning process based on the feedback gain (S4). The second feed-forward gain (K) and the feedback gain (K1) are used to establish a control system. In this manner, a control system having an optimum feed-forward gain and an optimum feedback gain can be established.

Abstract: A corrective positioning method in a robot, capable of eliminating degraded positioning accuracy attributable to inherent errors in the robot. By using displayed rotary angles of first and second links (1, 2) determined by a mastering sequence associated with known points, a simultaneous equation including, as unknowns, link length errors (.DELTA.11, .DELTA.12) and actual rotary angles (.theta.1, .theta.2) of the links is solved, to thereby determine the link length errors, errors (.DELTA.X0, .DELTA.y0) of a pivotal center position of an arm, and errors (.DELTA..theta.10, .DELTA..theta.20) of rotary angles of the links.

Abstract: The robot control apparatus according to the present invention is so adapted that, with regard to all kinds of motions commanded of a robot, the maximum velocity and time constant conforming to the type of robot motion can be designated for respective robot control axes (3) by a controller (1) which includes a selection table memory (4).

Abstract: An articulated industrial robot has an articulated horizontal arm assembly which includes horizontal arms (20), a vertically movable shaft (20) mounted on the extremity of the horizontal arm assembly, and a motor for driving the vertically movable shaft. When directly teaching motions to the vertically movable shaft through a direct teaching operation by an operator, the current control unit of a motor control unit for driving the motor for driving the vertically movable shaft is disconnected from a signal line connected to a robot control unit, and a torque calculating circuit is provided for deciding a motor torque corresponding to the sum of the weight of the vertically movable shaft and the respective variable weights of an end effector attached to the lower end of the vertically movable shaft.

Abstract: In an industrial robot employing electric motors (Mz, M.theta., Mu, Mw) as drive sources for driving functional robot units for movement respectively about articulatory axes (Z, .theta., U, W), electric drive currents supplied to the electric motors (Mz, M.theta., Mu, Mw) associated with the articulatory axes (Z, .theta., U, W) are detected by a current detecting unit (30), the detected electric drive current supplied to the electric motor (Mz, M.theta., Mu, Mw) associated with one selected articulatory axis among the articulatory axes (Z, .theta., U, W) is sampled every predetermined minute sampling time in a period between a first time and a second time in a robot control program for controlling the motions of the functional robot units respectively about the articulatory axes (Z, .theta., W), computing means (CPU) calculates the ratio of the root-mean-square value of the electric current supplied to the electric motor (Mz, M.theta.

Abstract: Provided is a compact first arm (12) of an industrial robot having articulated horizontal arms, which first arm has a direct drive motor (19), an electromagnetic brake (25), and a rotary encoder (34, 36) disposed close to each other concentrically between the first arm (12) and a base post (10) supporting the first arm (12), and has another direct drive motor (39), another electromagnetic brake (45), and another rotary encoder (54, 56) disposed close to each other concentrically between the first arm (12) and a second arm (14) rotatably supported by the first arm (12).

Abstract: A cable arranging device for an industrial robot has a cylindrical support casing (2), a swing casing (3) supported on the support casing (2) and swingable about the axis of a swing shaft, and cables (5) interconnecting the swing casing (3) and the support casing (2). One end of a substantially C-shaped cable guide (4) is pivotally supported in the swing casing on the axis of the swing shaft, the other end of the cable guide is pivotally supported in the support casing on the axis of the swing shaft. Spaces for allowing the cable guide (4) to swing therein through a prescribed angle are defined respectively in the swing casing (3) and the support casing (2).

Abstract: A system for controlling a robot includes a control portion (7) for supplying a control signal to and receiving a control signal from a servo unit (6) for carrying out a signal supply and a signal feedback to an electric motor (5) for driving a shaft executing a Z-axis linear motion, and threshold value supply portion (8) for supplying a threshold value to the control portion. Based on a comparison between a motor torque instruction value and a threshold value supplied from the threshold value supplying portion, an alarm is delivered and the process subsequently proceeds to a step of dealing with an abnormal condition when said motor torque instruction value becomes greater than a predetermined threshold value.

Abstract: A direct-drive-type multi-articulated robot comprising: a stationary support shaft (14), a cylindrical rotary casing (16) surrounding the stationary support shaft (14), a first robot arm (18) joined to the upper end (16a) of the rotary casing (16), a second robot arm (20) pivotally joined to the extremity of the first robot arm (18), a direct-drive motor (M.theta.) interposed between the lower end of the rotary casing (16) and the lower end of the stationary support shaft (14) to drive the rotary casing (16) and the first robot arm (18) together for turning motion, a brake gear (24) interposed between the upper end (14a) of the stationary support shaft (14) and the first robot arm (18) to arrest the turning motion of the first robot arm (18), and an encoder (26) for detecting turning motion, interposed between the upper end (14a) of the stationary support shaft (14) and the first robot arm (18).

Abstract: An arm structure for an industrial robot, comprising a first robot arm (16) supported on top of a vertical robot shaft (14), and a second robot arm (20) pivotally joined through a transmission-reduction gear box (18) to the free end of the first robot arm (16). A plurality of coupling bolts (22) are extended through the interior of the first robot arm (16), each coupling bolt (22) has one end (22b) fastened to the flange (18b) of the transmission-reduction gear box (18) and the other end (22a) projecting from and fastened to the rear end of the first robot arm (16). Fastening nuts (24) each engage at least one end (22a or 22b) of each coupling bolt (22) to couple the first robot arm (16) and the transmission-reduction gear box (18) so as to preload the first robot arm (16) by a compressive force.

Abstract: An industrial robot having replaceable modules assembled on a bed (2) housing a drive mechanism therein is composed of blocks (1, 3, 4, 5, 9) which comprise members of compatible common structures that can be selected and assembled as modules. The blocks have engagement portions compatible with those of modules of other specifications. Therefore, different robot specifications can easily be met, and the modules can be replaced with those modules which are effective in a wide range. The blocks of the industrial robot can easily be assembled and disassembled.

Abstract: An industrial robot brake apparatus for braking a mechanism that drives a support shaft supporting an arm in a freely extendable manner is capable of forming a clearance between a fixed brake member, which is for stopping rotation of a screw rod that extends and retracts the support shaft, thereby positioning the working plane of the arm, and a movable brake, thereby facilitating replacement of a belt and inspection of the brake mechanism, such as a brake shoe.

Abstract: An apparatus for limiting range of motion of an industrial robot in accordance with the invention includes an indicating section (7) for indicating e.g. angles of rotation provided on a stationary side (1) of the swivel portion of an axis about which swiveling motion is possible. A range limiting member (6) having a dog and a stopper is movably disposed on the indicating section (7). When the industrial robot attempts to rotate beyond a stipulated range of rotation during operation, a limit member (81) provided on a movable side (2) of the axis portion contacts the dog (61) on the stationary side (1) to detect overtravel, whereby a warning is issued to the effect that the stipulated range of rotation has been exceeded. When the robot attempts to rotate further due to inertia, a shock absorber (82) strikes a stopper mechanism (62) to prevent excessive rotation.

Abstract: An apparatus for setting an industrial robot at the standard position comprises a block (19) to be measured, which is attached to a top end portion (18) of a wrist of the industrial robot, and a supporting member (23) for the measurement, which is attached to a fixing base (11) of the industrial robot. The block has three planes (20, 21, 22), orthogonal to one another, to be measured, and the block is positioned to the top end portion of the wrist so that the three planes to be measured are set at predetermined positions relative to the top end portion of the wrist. The supporting member has three frames (24, 25, 26) orthogonal to one another, and the supporting member is positioned relative to the fixing base so that the three frames take predetermined positions relative to three-axis orthogonal coordinates predetermined on the basis of the fixing base. By a plurality of dial gauges (27 through 32; 37 through 42), the positions of the planes of the block are measured.

Abstract: A shaft supporting mechanism of an industrial robot in which an arm is supported by a freely extendable support shaft inside a hollow post and a working plane of a working arm is variably set is provided, with plural sets of linear support guides in opposed relation about a drive mechanism of the support shaft. As a result, the support shaft is held in the post stably and balanced in the vertical direction even if an external force attempting to tilt the support shaft is applied during up-and-down movement of the support shaft or operation of the working arm.

Abstract: A wrist driving mechanism for an industrial robot has a first base wrist unit (13) supported on the free end of a robot arm (11) and capable of rotating about a first axis (.gamma.). The first base wrist unit (13) is mounted with a second base wrist unit (14) capable of rotating about a second axis (.beta.). The second base wrist unit (14) is mounted with a fore wrist unit (15) capable of rotating about a third axis (.alpha.). The robot arm (11) is provided along the longitudinal direction thereof with a first power transmitting unit (16) for transmitting a rotative power to the first base wrist unit (13). A second power transmitting unit (19) for transmitting a rotative power to the second base wrist unit (14) is formed along the robot arm (11) and the first base wrist unit (13). A motor (25) for driving the fore wrist unit (15) for rotation is mounted on the first base wrist unit (13). The driving shaft of the motor (25) is coupled with a first transmission shaft (26) extended along the second axis (.beta.

Abstract: An industrial robot of the articulated arm type comprises a movable robot body (11) arranged on a base (10). An upper arm (13) having root and tip portions is rotatably pivoted to the robot body (11) at the root portion thereof. A forearm (16) having rear and front ends is rotatably pivoted to the tip portion of the upper arm (13) at a portion between the rear and front ends. Preferably, a wrist assembly (20) includes two moving elements (21,22) which are rotatable about different axes in relation to the front end of the forearm (16). The moving elements (21,22) of the wrist assembly (20) are rotated about the corresponding axes by means of wrist drive units (27, 28), respectively. The wrist drive units (27, 28) include first sprockets (29, 36), respectively, each rotatably arranged in the rear end of the forearm (16). Drive motors (31, 37), each rotating the first sprockets (33, 39), are arranged on the rear end of the forearm (16 ), respectively.

Abstract: A robot hand to be joined in use to the free end of an industrial robot wrist unit (10) is provided with a right and left work gripping units (28b and 28a) having pairs of work gripping fingers (30b and 30a), respectively, and separately disposed on the right and the left sides of a hand base, and an offset adjusting mechanism (34, 36, 40 and 42) for fastening the hand base with fastening means after the completion of the lateral adjustment of the hand base by a desired degree with respect to the wrist unit (10).