Hitachi, Ltd.

Hitachi Keiyo Engineering Co., Ltd.

Masaki Sumita

Norihisa Miyake

Koichi Sugimoto

Shinichi Sarugaku

A method of controlling the movements of a robot having a plurality of degrees of freedom includes expressing the attitudes of a hand or a working tool fitted to the arm end of the robot, the by the use of base vectors of a rectangular coordinate system fixed to the hand or the working tool. The attitudes are given as coordinate components related to a rectangular coordinate system which is fixed to the pedestal of the robot and which serves as reference. Interpolation and movement control of the robot is performed on the basis of the coordinate components. By performing control, based on the coordinate components real-time calculation processings is reduced highly accurate robot movement which is smooth in terms of both time and space is accomplished.

Method of controlling robot movements

A method and apparatus for controlling the tracking path of a working element so that the working element moves along a path having a predetermined positional relationship with a working object by adjusting the relative positional relationship between the working element and the working object through the movement of individually movable at least one moving element. The method and apparatus allot individual coordinate systems each having a discriminator to the working element, the working object and the moving elements to provide coordinate systems with the corresponding discriminators, set as a coordinate system expressing the data for controlling the movement of the working element a first coordinate system selected from the coordinate systems, describe, using a second coordinate system selected from the coordinate systems, the data representing the positions of the working element corresponding to specific points on the tracking path along which the working element is to move on the basis of a prescribed working schedule, store these data together with the discriminators representative of the corresponding coordinate systems, decide in executing a real work if or not the first coordinate system and the second coordinate system are the same from their discriminators, and, if both coordinate systems are different coordinate systems, converts the position data of the working element corresponding to the specific points into the data expressed in the first coordinate system, and control the movement of the working element on the basis of the converted data.

Method and apparatus for controlling tracking path of working point of

There is provided an operation control method for an industrial robot having a plurality of joints, cooperation of these joints allowing a hand or an end effector attached to the hand to perform necessary operation comprising the steps of representing a position and orientation of a hand effecting point relatively determined with respect to the hand or the end effector by a generalized coordinate system suitable for describing the task, deriving respective displacement values of the plurality of joints corresponding to the position and orientation information by using means such as computation, and making the hand effecting point perform necessary operation. For at least one joint among the plurality of joints, displacement is approximately derived by using approximate solution. For remaining joint among the plurality of joints satisfying a parameter or parameters to be controlled especially accurately among the position or position and orientation of the hand effecting point, strict solutions are derived by using the approximate solution of the above described at least one joint. the operation of the hand effecting point is thus controlled.

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Yachiyo, Japan

Masaki Sumita