Abstract: A system for setting a tool coordinate system brings directions ( , , ) of respective basic axes of the tool coordinate system into coincidence with directions (X, Y, Z) of basic axes of a robot reference coordinate system. A tool center point (TCP) serves as an origin, and the system causes a robot to memorize metric values on each motion axis of the robot at the moment of coincidence as setting information for setting the tool coordinate system. The system uses this setting information as information for subsequent robot motion. With the present invention, the setting of tool coordinates, which was a troublesome operation in the prior art, can be performed easily and accurately through a simple method.

Abstract: A uniform velocity control method for rotating a first movable element (3) at a uniform velocity in a rectilinear-to-rotational motion converting mechanism, in which a second movable element (2c) is moved along a linear shaft (2a) and the first movable element is rotated in dependence upon rectilinear movement of the second movable element. The uniform velocity control method includes (1) a second step of monitoring a position of the second movable element along the linear shaft; (2) a second step of calculating a traveling velocity of the second movable element, which traveling velocity is for rotating the first movable element at a uniform velocity, in dependence upon the position of the second movable element along the linear shaft; and (3) a third step of moving the second movable element at the calculated traveling velocity to make the rotational velocity of the first movable element uniform.

Abstract: The two-axes wrist assembly of the chain-drive system for an industrial robot has a base wrist unit (12) disposed on one side of the robot arm (11). A hollow shaft (13) is fixed at one end thereof to the base wrist unit and is supported at the same end on one side wall of the free end of the robot arm so as to be rotatable about a first axis (.beta.) intersecting the longitudinal axis of the robot arm at right angles. The other end of the hollow shaft is positioned opposite to the inner surface of the other side wall of the free end of the robot arm. A fore wrist unit (16) is supported on the base wrist so as to be rotatable about a second axis (.alpha.) intersecting the first axis at right angles. A through shaft (17) is provided rotatably within and coaxially with the hollow shaft. The fore wrist unit is interlocked with the hollow shaft by a pair of bevel gears (18, 19). A first sprocket (22) is provided on the other end of the hollow shaft coaxially with the same within the free end of the robot arm.

Abstract: A scaling method in an automatic welding machine equipped with a robot control unit for controlling a robot grasping a welding torch. The robot control unit obtains subsequent taught positions on the basis of taught position data indicative of primary welding points (P1, . . . Pn)) of a welding workpiece. The scaling method includes computing the direction of a normal vector (N) of the surface of the workpiece (WK) based on position data (Q1, Q2, Q3) indicative of any three points on the surface of the workpiece (WK), and obtaining, by correction, scaling points corresponding to the primary welding points on the basis of the direction of the normal vector N.

Abstract: An electric industrial robot comprises a movable robot assembly (10) forming therein an airtight chamber, and an electric drive unit for driving the robot assembly. The electric drive unit comprises a plurality of motors (36-41). The respective casings (36a-41a) of the motors are disposed within the airtight chamber (30) of the robot assembly. Electric cables (57-62) connected to the motors, respectively, are led through the airtight chamber into a fixed pipe (67) connected to the robot assembly. The interior of the motors and the interior of the airtight chamber are kept at a pressure higher than an atmospheric pressure outside the robot assembly.

Abstract: The industrial robot comprises a lower arm (13) provided on a robot body (12) pivotably about a first horizontal axis (C1). The lower arm (13) has provided thereon a forearm (14) pivotably about a second horizontal axis (C2). The forearm (14) is rotationally driven by a drive such as a motor (16). The robot body (12) has provided thereon a rotating disk (17) interlocked with the pivoting of the forearm (14) about the second axis (C2) and rotatable about the first axis (C1). Also the rotating disk (17) has secured thereon a first wheel (18) and coaxial therewith, the diameter of which is smaller than that of the disk. There is further provided a tension spring assembly (19) having one end thereof connected to the robot body (12) and which has rotatably mounted at the other end thereof a second wheel (21) having nearly the same diameter as that of the first wheel. Also provided is a chain (22) having one end thereof connected to the rotating disk (17) and the other end engaged on the first wheel (18).

Abstract: The cable supporting arrangement inside the base body of an industrial robot supports at least a cable (14) led through the interior of the base body (10) having a cylindrical inner surface (11) into the movable body (13) provided atop the base body pivotably about the axis (X) of the base body. An inner cylinder (15) is provided and fixed concentrically inside the base body. An annular space is defined between the inner cylinder and the base body. The resilient strip members (19, 20) have one end (21, 30) thereof fixed to the inner surface of the base body, and the other end (22, 31) fixed to the cylindrical outer face (16) of the inner cylinder. The strip member is curved at a selected portion such that the strip member sections before and after the curved portion are opposite to each other, and is forced under its own resilience onto the inner surface of the base body and the outer face of the inner cylinder when the movable body is in a selected pivoting position.

Abstract: The robot assembly of an industrial robot comprises a stationary robot component (11) and a plurality of movable robot components (12, 13, 14). At least parts of the stationary robot component and the movable robot components have airtight chambers (15, 16, 17) communicating with each other and intended to be kept at a pressure higher than a predetermined level which is higher than an external atmospheric pressure. Robot driving motors (18 to 23) for driving the movable robot components are arranged within the airtight chambers. A driving motor controller (27) for driving and controlling the robot driving motors is connected to the robot driving motors by means of electric cables arranged within the airtight chambers. Pressure switches (25) supply signals to the driving motor controller to stop the robot driving motors, respectively, upon detection of the pressure in the airtight chambers when the pressure in the airtight chambers drops below the predetermined level.

Abstract: An acceleration and deceleration system smoothly controls acceleration and deceleration of an electric motor for driving a movable member of a machine tool or a robot. The acceleration and deceleration system has a linear acceleration and deceleration circuit (3) for receiving interpolation data issued from a pulse distributor (5) and effecting a linear acceleration and deceleration computation on the received data, and an exponential acceleration and deceleration circuit (4) for receiving an output signal from the linear acceleration and deceleration circuit (3) and effecting an exponential acceleration and deceleration computation on the output signal, the circuits (3), (4) being connected in series with each other.

Abstract: A method and a device for determining the reference positions of an industrial robot, in which datum surfaces (1a, 1b) are formed in the fixed base (1) of an industrial robot having a plurality of degrees of freedom of motion. The reference positions with respect to directions corresponding to the degrees of freedom of motion of the wrist base (5) and the wrist front section (7) are determined relatively to the fixed base (1) by means of a jig body (11) located fixedly on the datum surfaces, and measuring instruments (14 to 19) attached to the fixed base (1) at predetermined reference positions thereon, and the determined reference positions are given and taught to the NC unit of the industrial robot.

Abstract: A safety method in a robot system including at least a robot (1), peripheral equipment (2-5) serviced by the robot, a robot control unit (6) which causes the robot to execute predetermined services for the peripheral equipment, and a teach control panel (9). A door (11) is provided at the entrance to a robot operating zone, and the door is provided with a safety switch (12) for terminating automatic operation of the robot when the robot is in an automatic operating state. When the safety switch is actuated by opening the door, robot motion in the automatic operating state is decelerated and stopped. During the time that the safety switch is in the actuated state, the robot is placed in a playback operation state to enable control that is performed through the teach control panel.

Abstract: An industrial robot arc control method subjects the position of a working member to circular-arc control by interpolation while controlling the target angle of the working member with respect to a surface to be worked, which working member is mounted on the wrist of an industrial robot. The industrial robot circular arc control method includes obtaining corresponding points (P1, P2 . . . ; Q1, Q2 . . . ;) of the tip and base of the working member (TC) at plural taught points for circular-arc control of the tip of the working member, which is mounted on a wrist (HD) of the robot, finding interpolated points of the tip and base of the working member by interpolation from the corresponding taught points, and obtaining command quantities for the motion axes of the robot from the interpolated points.

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: A method of returning a movable machine element having a flat dog to a zero point includes advancing the movable machine element in the direction of the flat dog, stopping the movable machine element after a changeover signal (S.sub.D) produced by the flat dog is detected, reversing the direction of the movable machine element, moving the movable machine element a first predetermined distance (L) and stopping it after the changeover signal (S.sub.D) is received again, then moving the movable machine element in the opposite direction a second predetermined distance (l) shorter than the first predetermined distance (L) and stopping the movable machine element, thereafter moving the movable machine element at a low velocity and stopping it at an initial one-revolution signal of a servomotor, which operates the movable machine element, after the changeover signal produced by the flat dog is detected.

Abstract: An absolute position detecting system for a servocontrol system which has its operation controlled in accordance with a numerical control program. Resolvers 202 and absolute encoders 110 made rotatable with a servomotor 105, are set at a predetermined revolving ratio so that the absolute positions of operating axes may be detected highly accurately from the revolution outputs of the two. The detecting operations can be performed for the plural operating axes by using one detecting circuit commonly.

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: In an absolute position detecting system for a servocontrol system operatively controlled according to a numerical control program or the like, the absolute position of an operating shaft is detected with a high accuracy based on outputs of a resolver 106 and an absolute encoder 110. The resolver 106 and absolute encoder 110 rotate with a servomotor 105 at a prescribed revolution ratio, so that variations in the absolute position of the operating shaft at the time of a malfunction in the servocontrol system can be stabilized quickly.

Abstract: A machining center equipped with an integral robot device having a manipulating hand capable of approaching a spindle of the machining center, a tool storing magazine mounted on a machine body, a workpiece supply table disposed on a floor in the vicinity of the machine body, and a work table of the machine body so that an exchange of cutting tools may be carried out by the manipulating hand between the tool storing magazine and the spindle, and so that an exchange of workpieces may also be carried out by the manipulating hand between the tool storing magazine and the work table.

Abstract: A vertical-type machining center having a spindle carrier which travels in the vertical direction and a turret capable of both rotation and upward and downward movement provided on the spindle carrier, wherein tools are automatically changed over through rotation of the turret caused by relative movement between the turret and the spindle carrier when the upward movement of the turret is checked by a restraining member. A Z-axis position pulse generator is provided on a spindle mechanism drive member, such as the vertical drive motor or a screw shaft, and is adapted to generate a pulse for each revolution of the drive member. The pulses are counted by a counter which delivers a counted value for use in computing the vertical position of the spindle mechanism. The arrangement is such that the rotational speed of the vertical drive motor is controlled so as to move the spindle mechanism at an optimum speed suitable for the vertical position thereof.

Abstract: An indexing table assembly adapted to be mounted on a machine tool or other industrial machine, comprising first and second screw elements coaxially engaged with each other and mounted for movement along their axes, mechanism for moving said first screw element along its axis, a turntable connected to said second screw element and movable therewith, mechanism preventing said second screw element from being moved beyond a predetermined range, said mechanism for moving said first screw element comprising a cylindrical piston directly connected to said first screw element, a circular fluid chamber in which said cylindrical piston is mounted for movement, said cylindrical piston separating said chamber into first and second chambers, a source of pressurized fluid, a control valve for controlling the flow of pressurized fluid into either said first chamber or said second chamber with the result that when the pressurized fluid flows into said second chamber the first screw element is moved positively in one directi