Fanuc Corporation

Ntt Docomo, Inc.

Takayuki Ito

Atsushi Watanabe

Hiromitsu Takahashi

Tatsuo Karakama

Hajimu Kishi

Shinsuke Sakakibara

Tetsuya Kosaka

Yoshiharu Nagatsuka

Hiroji Nishi

Tohru Mizuno

Tomoyuki Terada

Takeaki Aramaki

Toru Shirahata

Hirotsugu Kaihori

Atsuo Nagayama

Hidenori Miyamoto

Kouichi Ohkanda

Akiko Takano

Shikiko Kawano

Toru Nasu

Kazuto Hirose

A robot program adjusting system () adjusting an operating program of a robot arm having a plurality of axes including an overload identifying means () for successively reading operational instructions from said operating program of said robot arm to run simulations and thereby identify an axis where overload is acting from said plurality of axes, an additional operation generating means () for generating an additional operation for an axis other than the axis identified by said overload identifying means () to lighten the load of said identified axis, and a program adjusting means () for adjusting the operating program of said robot arm based on the additional operation generated by said additional operation generating means (), whereby the load acting on an axis with a large load can be lightened without trial and error.

Robot program adjusting system

When a mail serverand a mail serverare in a failover state, switchesselect communication paths E, F. A temporary save serverstores email received from a mail reception serverduring the failover in a disk storage, and after the completion of the failover, transmits to a mail server (e.g., mail server) that has been switched to function as a primary system an email stored in disk storageand a write request for a disk storage. Mail server, upon receiving an email and a write request from temporary save server, stores the received email to disk storageto update stored content.

Communication system with primary device and standby device to prevent suspension of service of the system

First, an operator sequentially teaches the start point A, the end point F and junction points B, C, D, E on the welding path by moving the torch head by jog feed without paying attention to the torch orientation. Next, a reference plane to define the orientation of the torch is specified, and an inclination angle and a forward angle representing the torch orientation be inputted into a robot controller. On the basis of these inputted angle data and the taught data, a basic welding orientation is automatically calculated. Further auxiliary points are set around the junction points B through E each forming corner parts connecting straight lines; tool vectors which may give a smooth torch orientation change through the corner parts are automatically calculated for the auxiliary points and the junction points; and on the basis of the results, a welding program is produced. Among elements which determine the torch orientation, an element relating to the rotation around the torch axis reflects the state at the time of teaching of points A to E.

Method for teaching welding torch orientation

A work mounting device in which an operation for teaching a robot to mount a work on a work mounting member is automated. The work is gripped by a hand placed on an arm tip portion of the robot and the operation for mounting the work on the work mounting member is taught. A plurality of distance sensors are disposed on the work mounting member or the hand. Distances between each sensor and the work or distances between each sensor and the work mounting member are measured. A robot controller maintains an attitude of the robot so that the distances detected by the distance sensors are uniform and, at the same time, allows the work to approach the work mounting member so that a plurality of holes of the work are engaged with a plurality of respective protrusions of the work mounting member. Based on the distance data detected by the distance sensors, a disturbance estimation observer, a load torque on motors for each axis or the like, the movement of the robot is stopped automatically when the work reaches a position where the work is in contact with the work mounting member or is very close to contact therewith. The position and attitude of the robot at this time is taught.

Work mounting device

A robot control apparatus having an expanded and improved backward operation function. During forward operation according to an operation program, command types, line numbers, robot positions, I/O signal states before execution of related commands, and values before execution of computation commands are stored in a history table. In the backward operation, the data written in the history table is read backward, command type discrimination is made, and backward operation processing is executed in accordance with the result of discrimination. For backward operation dedicated commands, a separately taught backward operation dedicated command is read and executed. If, however, the read command is a command to output a signal to a cooperative device, the signal output command is executed after completion of the robot motion to the stored position. For I/O commands, I/O signals are automatically inverted or are individually set after the motion to the stored position is completed.

Robot control apparatus with function for robot backward operation

An arc welding method capable of easily varying welding conditions such as welding speed, voltage and electric current. The method comprises the steps of teaching a start point to start varying welding conditions such as welding speed, voltage and electric current and an end point to terminate the variations of welding conditions such as the welding speed, the voltage and the electric current, as well as setting the welding conditions at the start point and the end point for gradually varying the welding conditions such as welding speed, voltage and electric current towards end point. By simply setting positions of the start point and the end point and the welding conditions at these positions, it is possible to gradually vary the welding conditions from the conditions at the start point to the conditions at the end point while a welding torch is moved from start point to the end point, thereby contributing to the simplification of the welding condition varying procedure.

Arc welding method

A robot controller resolving a path deviation caused in relation to override processing or temporary stop. A motion planning section constituting software of the robot controller forms a motion plan of a robot with no consideration of overriding and outputs it to an interpolation processing section. The interpolation processing section carries out interpolation processing at each period of calculation processing, calculates a motion amount at each ITP and outputs it to a filtering section. An output filtered for acceleration or deceleration control at the filtering section is processed by an overriding processing section having an operational shutter. An output after the processing to which an override value .beta. (0.ltoreq..beta..ltoreq.1) common to respective axes has been applied is constituted by velocity and acceleration respectively multiplied by .beta. and .beta..sup.2. Acceleration or deceleration of two operation is uniformly exhausted at a corner portion where two operation overlap and, therefore, path error is not caused. Even when overriding is changed in passing through the corner portion, operation is similarly carried out. By gradually changing overriding in deceleration and acceleration before and after a temporary stop, path deviation accompanied by a temporary stop can also be resolved.

Robot controller

Jog feeding method for robots

A cylindrical workpiece as a welding object is rotated by an external drive shaft. A welding torch and a laser sensor are attached to a distal end portion of a robot. A deflective scanning laser beam from a laser sensor is projected on a region just ahead of a weld point, whereby a light spot trace is formed extending in a direction perpendicular to a welding center line. A CCD camera of the laser sensor picks up the trace, thereby detecting a change of the thickness of a weld layer. In executing a weaving operation, the robot performs an alternating motion including components in the direction perpendicular to the welding center line. When the workpiece rotates so that the range of projection of the laser beam, starting from a region without any weld layer thereon, reaches a region for the formation of a first weld layer, a layer transition is detected by an increase of the thickness of the weld layer. Based on this point of time, control is effected to execute correction of the robot position, modification of welding conditions, etc.

Robot control system for executing multi-layer welding

When an operator selects one of many jog modes, including a tool feed mode, robot coordinate system feed mode, user coordinate system feed mode, joint feed mode, etc., a display controller displays a jog feed direction adapted for the selected mode for superposition on a robot image on a monitor screen. If the operator depresses any of jog feed direction selector keys, the jog feed direction corresponding to the depressed key is displayed for discrimination.

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Yamanashi, Japan

Takayuki Ito