Abstract: A small-locus machining apparatus is attached to the distal end of a wrist of a robot but operable independently of a robot body. First and second drives of the apparatus are mounted on a base in such a manner that respective output spindles are parallel with each other. First and second rotational arms are coupled to the output spindles through decelerators, which are directly connected to the drives, allowing rotation in a plane orthogonal to the output spindles. These rotational arms and links interconnecting the rotational arms constitute a link mechanism having, for example, five joints. A tool is attached to this link mechanism, and the rotational amounts of the first and second arms are detected to determine the coordinate position of the tool.

Abstract: A window mechanism for a sensor provided at the distal end of a robot arm of an industrial robot comprises a housing for enclosing the sensor which housing includes an opening, a glass plate for closing the opening, wiper for wiping the outer surface of the glass plate, a holder plate for slidably holding the glass plate member on the housing, and an exchanger for exchanging the plate member held by the holder with a new glass plate.

Abstract: A diagnostic method in which data obtained from a real-time sensor are stored during the operation of a robot for later diagnosis of the operation state of the sensor. This method includes the steps of scanning an object by using a laser sensor, thereby obtaining sectional data; detecting a weld line position on the basis of the sectional data; storing in a memory the weld line position along with robot positions corresponding to the time of detection; and storing in the memory the sectional data when a predetermined robot position is reached with a conditional value set to "1", when the weld line position has first failed to be detected with the conditional value set to "2", or when the variation of the weld line position is larger than a predetermined value. The operation state of the sensor is traced on the basis of the weld line position and the sectional data stored in the memory, and various parameters for detection are set so that an optimum state for detection can be established.

Abstract: An overtravel detecting device, mounted on an angularly movable shaft of an industrial robot for mechanically determining and detecting the limits of rotation of the movable shaft, is attached to a rotating shaft (12) of a wrist portion (10) of an industrial robot and is provided with a pattern plate member (22) having two grooved paths (24) for setting the limits of rotation of the rotating shaft at predetermined position with respect to an origin position of the rotation, and a detecting element constituted by a limit switch (32) for transmitting an overtravel signal when the switch comes into contact with stop walls (24a, 24b) formed at ends of the two grooved paths for setting limits of rotation.

Abstract: A method for accurately detecting an abnormal load caused, e.g., by adhesion of the distal end of a spot gun. A flag F2 is set to "1" when a move command is outputted to move a movable part of a machine and is reset to "0" upon lapse of a predetermined very short period of time, and, while the flag F2 remains "0" during stoppage of the movable part, a disturbance torque T0, estimated by a disturbance estimation observer, is stored and successively updated. When a move command is thereafter outputted, and the flag F2 is set to "1", an estimated disturbance torque T1 is obtained, and if the absolute value .vertline.T1-T0.vertline. of the difference between the disturbance torque T1 and the disturbance torque T0, estimated immediately before the movable part is moved, is greater than a reference value Ts, it is determined that an abnormal load is applied, whereupon an alarm is outputted, a flag F1 is set to "1", and the motion is stopped.

Abstract: A laser robot having a height sensing device (13) arranged at a position very close to a laser-beam projecting machining head (9) so that the axis of the height-sensing device (13) is parallel to the longitudinal axis of the machining head (9), the three-dimensional distance data representing the positional relationship between the laser projecting nozzle (9a) of the machining head (9) and the measuring end (13a) of the height-sensing device (13) being stored in advance in the robot controller (10), the longitudinal distance between the height-sensing device (13) and a starting point of laser-beam machining being automatically measured from directly above the starting point, and a longitudinal distance between the laser beam projecting nozzle (9a) of the machining head (9) and the machining starting point being corrected on the basis of the three-dimensional distance data and the longitudinal distance measured by the height sensing device (13) to thereby accurately locate the machining head at a position corr

Abstract: A beam axis adjusting method of a laser robot including the steps of splitting a visible laser beam traveling along a laser beam pathway within the robot unit of the laser robot into a first laser beam traveling further along the laser beam pathway and a second laser beam traveling outside the robot unit, receiving the second laser beam by a target plate made of a semitransparent plate and mounted on the robot unit to form a light spot Sp on the front surface of the target plate, adjusting a relevant reflecting mirror unit disposed in the robot unit for the adjustment of the beam axis of the laser robot, and visually observing the light spot Sp from behind the back surface of the target plate while the relevant joint of the robot unit is in motion.

Abstract: A method of teaching a robot motion program, which facilitates the preparation of programs, and in which a required one of a plurality standard motion programs for operating a robot in accordance with stereotyped motion patterns is read from a memory of a robot control device and displayed on a display screen of a teaching control panel. An operator operates the teaching control panel to add, though the display screen, position and speed data etc. to the standard motion program, or modify, through the display screen, the data previously described in the standard motion program, whereby a motion program for a robot operation to be performed in accordance with a sterotyped motion pattern or a pattern similar thereto can be created easily.

Abstract: In carrying out precision laser-beam machining by using a laser-beam machining head driven by an additional motion-axis means 8 of a laser robot unit 1, a CPU accommodated in a robot controller 10 calculates time A+B necessary for a laser beam projecting nozzle to travel a distance between a position corresponding to a position of origin OR of a machining locus and a position corresponding to a starting point E on the machining locus at a quick-feed speed, and time C necessary for the laser beam projecting nozzle to travel the same distance in a laser-beam machining mode not including quick-feed operation, compares the times A+B and C, and provides feed motors MA and MB accommodated in the additional motion-axis means 8 with an automatic quick-feed command, when the time A+B is shorter than the time C to thereby enhance an efficiency of the laser machining operation.

Abstract: An adaptive proportional-plus-integral control system for controlling a robot or a machine tool which is subject to large load variation. The PI control system comprises a speed control loop and a pre-compensator provided in the speed control loop. The pre-compensator is equivalent to a system which is the combination of a reference model and an inverse system of a servomotor, and has adaptivity. Since the pre-compensator is incorporated into the speed control loop, robust control can be made even if the inertia of a load is largely variable.

Abstract: A cooling and cleaning unit incorporated in a welding position detector having a gas introducing conduit for introducing a single flow of a cooling gas under pressure into a hermetically sealed chamber of a casing for encasing therein a sensor unit of the welding position detector in the form of a convectional flow of cooling gas circulating around the sensor unit and removing heat from the sensor unit, a check valve unit having a gas inlet and a gas outlet and permitting the cooling gas under pressure to be discharged from the hermetically sealed chamber toward an outer face of a protective window of the welding position detector in the form of cleaning gas under pressure to thereby clean the outer face of the protective window while forming a gas curtain extending over the outer face of the protective window so as to prevent welding fumes and sputter from attaching to and depositing onto the outer face of the protective window of the welding position detector.

Abstract: A balancer device for balancing the moment generated by gravity on a robot arm, which is mounted at the one end thereof for rotation about a rotation axis and having an articulation on the opposite end, comprises a fluid-pressure operated spring means (7), an attachment portion (6) provided on the robot arm near the articulation, a tension transmitting member (2) for applying tension to the robot arm (1) by cooperation with the fluid-pressure operated spring means (7), and a plurality of guide means (3, 4, 5) provided for rotation extending and guiding the tension transmitting member (2). The tension transmitting member (2) is extended so as to pass the plurality of guide means (3, 4, 5) and the attachment portion (6), and to apply tension to the robot arm (1), whereby the balancer device balances the moment by gravity on the robot arm (1).

Abstract: The present invention relates to a position detecting method and its apparatus that is capable of improving detecting accuracy in a laser sensor using a Charged Coupled Device (CCD) as a light receiving element. A sum of products of an output C.sub.i of each cell in a light receiving element and a cell position X.sub.i is obtained, and the cell outputs C.sub.i are added. When the cell output C.sub.i exceeds a predetermined threshold value, a counter is reset. When the cell output C.sub.i decreases down below the threshold value, the sample hold signal SH is counted. When the counted value of the counter becomes a predetermined value, a division circuit divides the above-obtained sum of products by the above addition value to obtain a center of gravity of the sum of products as a light receiving position. Then, thus obtained value is stored in a latch buffer.

Abstract: An industrial robot is provided with a cable laying arm (20) extended on one side of a robot trunk (12) so as to form a dual arm structure in combination with a structural arm (18) extended on the other side of the robot trunk (12). A bundle (58) of cables capable of being detachably connected to the robot unit is extended in the cable housing element (50) of the cable laying arm (20) so that the cables including power supply cables and signal transmission cables are not exposed to the outside. The whole cable housing element (50) can be readily removed from the robot trunk (12) together with the bundle (58) of cables, in case any one of the cables is disconnected, to permit repair of the disconnected cable.

Abstract: A sliding mode control method is provided capable of improving the following ability of a control system with respect to a command at the time of change in the operating condition of a machine, and preventing vibration which tends to occur by the action of a spring element of the machine at the time of change in the operating condition. The processor of a servo circuit derives position deviation (.epsilon.) and speed deviation (.epsilon.) based on a command position (.theta.r) and an actual position (.theta.), estimates an torsion amount (.epsilon.n) and torsion speed (.epsilon.n) by effecting observer processing (Steps 100 to 101), and derives a switching variable (s) (102).

Abstract: The purpose of the invention is to properly determine the replacement time of a guard window of an arc sensor using an original function of the arc sensor.The apparatus for monitoring a guard window of an arc sensor according to the present invention is provided with an arc sensor guard window (28) mounted on an arc sensor unit (20) and a standard reflecting plate (30) located at a position a determined distance from the front surface of the guard window (28). And the apparatus detects the reflected light (27) from the standard reflecting plate (30) when a laser beam (26) scans the standard reflecting plate (30), before the guard window (28) is used for an arc welding operation. The apparatus memorizes the quantity of detected light reception as the first quantity. The apparatus then detects the reflected light (27) from the standard reflecting plate (30) in the same way as before, after the guard window (28) is used for an arc welding operation.

Abstract: A sliding mode including a process of feeding back an amount of twist for controlling a servo loop is controlled by reading the position of a servomotor and the position of a mechanical actuator drivable by the servomotor (SP1), calculating an amount of twist which is an error (SP2), calculating a switching surface Suf with a value produced by filtering the amount of twist (SP3), and selecting a switching input with the produced value (SP4, SP5, SP6). The amount of twist is filtered by a filter which has a numerator and a denominator which are of a first order. The filter allows a system to be realized which suffers less vibration and is robust against inertia fluctuations.

Abstract: A robot control method based on an acceleration/deceleration time constant wherein the acceleration/deceleration time constant of a servomotor is set for an optimum value for each block, to thereby control the operation of the robot. A reaching speed (Vu) is determined from an amount of movement (X) of a block, and based on the reaching speed, a maximum torque (Tmax) of the servomotor is determined and then a static load torque (T.sub.wn) is subtracted from the maximum torque (Tmax) to determine an acceleration torque (Ta.sub.n). Thereafter, based on the acceleration torque (Ta.sub.n) and the load inertia of the servomotor, an acceleration (a.sub.n) is determined and an acceleration/deceleration time constant (.tau.) is determined from the acceleration (a.sub.n), and accordingly, an optimum acceleration/deceleration time constant is determined.

Abstract: An industrial robot is provided with robot hands (44, 46) capable of being moved by turning actions between a workpiece handling position to which a workpiece is transported and at which the workpiece is fed to the chucking device (10) of a machine tool and a standby position away from the workpiece handling position. The robot also incorporates a robot hand (42) capable of being turned in a plane at the workpiece handling position to align a workpiece with the chucking device (10) of the machine tool, and a pneumatic cylinder actuator (48) capable of linearly moving the robot hand (42) toward the chucking device (10) and away from the chucking device (10) so as to remove a workpiece from the chucking device (10). The industrial robot can be readily fixed to the bed of the machine tool by bolts, for example.

Abstract: An apparatus for holding a plurality of workpieces (W) in a stack on a pallet (22), supporting the workpieces (W) in place on the pallet (22) by a plurality of workpiece support rods (26), and transporting and transferring the uppermost workpiece by a workpiece gripping hand (50) provided with gripping fingers (54) to a desired position, is provided with elastic lifting springs (32) for continuously biasing the workpiece support rods (26) upward to support the workpieces (W) stably in place by the upright work support rods (26). The workpiece gripping hand (50) grips the uppermost workpiece (W) with the gripping fingers (54) without interference, after depressing the workpiece support rods (26) with a depressing plate (56) provided on the back side of the gripping fingers (54) so that the uppermost workpiece (W) is exposed above the upper ends of the workpiece support rods (26), and then transports the workpiece (W) to a desired position.