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 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: A piping arrangement in which a plurality of sealing means (70 through 78) are arranged on a sheathing pipe (42) provided as an outer pipe of a robot wrist (18) of a laser robot to thereby define annular chambers (84 through 90); the annular chamber (86 and 90) being used as a gas-carrying annular chamber for transferring an assist gas from one line to another, and a liquid-carrying chamber for transferring a liquid coolant from one line to another; the assist gas and the liquid coolant being supplied and returned through the gas-carrying annular chamber and the liquid-carrying annular chamber (84 and 90).

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.

Abstract: A sealing gun (31) of a sealant application unit, which controls the flow of the sealant in accordance with the value of an input signal, is attached to the end of a robot arm. The value of a signal applied to the sealant application unit (30) is controlled in association with acceleration/deceleration control of the moving speed of the sealing gun. The moving speed (TSA) of the sealing gun and the flow (SC) of the sealant discharged from the sealing gun are in direct proportion; therefore, the bead width becomes uniform independently of the moving speed (TSA) of the sealing gun.

Abstract: A cooling means for removing heat generated in a portion of a solid ball-and-screw shaft (27) provided for a screw mechanism accommodated in an industrial robot and engaged with a linear motion nut (28) accommodated in the linear motion mechanism. The cooling means permits a cooling medium, typically cooling air, to flow through a cooling medium passage (33) formed in an unthreaded end portion of the shaft (27) and having an end connected to a rotative drive motor (M), to flow through a radial hole (34) having one end connected to the cooling medium passage (33) and the other end opening into an annular space surrounding an external surface of the shaft formed with a screw thread (27a), and to flow through the annular space along the surface of the threaded portion of the shaft (27), to thereby remove heat generated at the threaded portion engaged with the linear motion nut (28).

Abstract: A high-density installation type robot able to be installed side by side with another such robot, to work on an object at the same time is provided. A robot wrist assembly (30) is equipped with three rotary axes (.alpha. axis, .beta. axis, .gamma. axis), and a robot arm (26) having the robot wrist assembly (30) mounted on an end thereof is given a rotary axis (.theta. axis). Further, a bracket-shaped holder (24) holding the robot arm (26) is provided in such a manner that it can move vertically (V) and linearly (FR), whereby a large rectangular parallelepiped, three-dimensional operating area can be secured and a wasted operating area eliminated.

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 wrist mechanism comprising a pipe 52 extended in relation to a front .alpha.-axis among the three axes of motion (.alpha.-axis, .beta.-axis, .gamma.-axis) of a wrist, on a center axis A--A of turning motion through the center of an .alpha.-axis reduction gear, a universal pipe coupling 61 provided in relation to a .beta.-axis on the center axis B--B of motion, a pipe 51 having one end connected to the pipe 52 and the other end connected to the pipe coupling 61, and a hose 4 extended along a support arm 3 and connected through the pipe coupling 61 to the pipe 51. The wrist mechanism is incorporated into a robot for work in which a fluid is used, such as an application of an adhesive and sealant.

Abstract: When an adjustment of an optical path followed by a laser beam is performed by using an adjusting laser beam emitted by a laser oscillating source to obtain a condition such that the laser beam introduced in a robot unit of a laser robot is correctly directed to a light condensing device (36) provided at an extremetity of the robot unit after changing the direction thereof due to a reflection by light reflecting mirrors arranged at respective joints in the robot unit, a position of the optical path of the adjusting laser beam projected by the light condensing device (36) in the interior of the robot unit (30) is detected by an optical sensor (46), and a different position of the optical path of the adjusting laser beam is simultaneously detected by a separate optical sensor (45) arranged at a position on the optical path for the laser beam located upstream with respect to the light condensing device (36), and an adjustment is carried out so that the center of movement of each of the joints of the robot unit (

Abstract: An industrial robot provided with a cable arrangement system in which a hollow shaft (3) is arranged to extend vertically from a robot base (1) into a rotational trunk (2) about a rotational axis thereof, and a plurality of cables (7) are arranged to be spaced from one another around the outer periphery of the hollow shaft (3) by cable clamps (4) mounted on the outer periphery of the hollow shaft (3) and having a plurality of cable receiving grooves (41).

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: A collision detection/drive stoppage method capable of promptly detecting a collision of machine operating parts driven by servomotors with a foreign object, and of promptly stopping drive of the machine operating parts upon detection of a collision, thereby preventing or lessening damage to a machine, etc., caused by the collision. A digital signal processor of an axis controller, forming a software servo system, periodically calculates a velocity deviation (.epsilon.v) in accordance with a command velocity (Vc) calculated based on a command from a main computer and an actual motor velocity (V) from a pulse coder of the servomotor (S2), determines whether the absolute value (.vertline..epsilon.v-.epsilon.v'.vertline.

Abstract: An operation control system for a scanning galvanometer associated with an arc sensor (20) of a welding robot for sensing a weld line, and having a swing mirror (23) integral therewith for a laser beam scanning. A memory (43) stores waveform data of a galvanometer drive command current obtained by synthesizing a constant-speed command current and an acceleration/deceleration command current, and an address circuit (42) causes the waveform data to be output from the memory (43) at predetermined intervals. A D/A converter (44) converts the output of the memory (43) to an analog value, and a scanner drive circuit (45) drives the galvanometer (22), which swings the swing mirror (23) to detect the weld line.

Abstract: An industrial robot having a plurality of axes drivable by respective servomotors is stopped in operation after detecting a collision of the industrial robot with foreign matter. The monitoring of a position error of a servomotor for the axis with respect to which the collision is detected is stopped (S11), and the speed command for that axis is set to "0" (S12). A reverse torque is generated (S13) to decelerate and stop the servomotor. After elapse of a predetermined period of time (S14), the monitoring of a position error is resumed (S15). If the position error exceeds a predetermined value (S31), then an alarm is activated (S32). Then, currents supplied to all the servomotors are cut off (S33), thus stopping the operation of the robot in a short period of time.

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.