US 4,166,543 A · Method and means for controlling an industrial robot

Abstract

Robot control with programmed positioning modified by a sensor sensing position error, force or the like. To maintain flexibility, the sensor axis need not coincide with any of several degrees of freedom of the robot. To employ sensor generated signals to modify programmed positioning where sensor and robot degrees of freedom are different, a normalized correction is computed relating a sensor output to each axis of freedom. Merely multiplying sensor output with the appropriate normalized correction provides a quantity in the proper coordinates for correction or position modification, as desired. Further, the robot includes apparatus to change direction of motion under certain circumstances, i.e., a collision with an obstruction. This allows the robot to move around obstructions whose location and extent were unknown at the time of movement programming.

Claims22

Dependent claims

A method for controlling movement of an industrial robot with an arm movable with more than one degree of freedom in a robot coordinate system, including at least one transducer for sensing deviations of said arm in a definite sensing direction for each transducer wherein said transducer sensing directions do not correspond to any coordinate in said robot coordinate system, comprising:

(a) locating said arm in a first position within an intended operating range of said arm;
(b) displacing said robot arm a distance in a predetermined direction which has a component in said sensing direction of a transducer;
(c) sensing and storing robot arm coordinates, expressed in said robot coordinate system, of said displacement;
and
(d) correcting robot coordinates during operation within said intended operating range upon sensing deviation sensed by said transducer with a correction calculated based on said stored values.

2 more elements

Apparatus for controlling movement of a movable arm of an industrial robot with more than one degree of freedom in robot system coordinates, including at least one transducer for sensing deviation in a definite sensing direction for each such transducer wherein axes of said robot system coordinates are each different from each of said sensing directions, comprising:

a memory for storing coordinates of said robot arm for controlling subsequent movement of said arm,
means for positioning said arm in one position within an intended operating range,
means for displacing said robot arm a distance in a direction with at least a component in said sensing direction of said at least one transducer,
means for storing coordinates of said displacement in robot system coordinates in said memory,
arithmetic processing means coupled to at least one transducer and responsive to signals therefrom, and further coupled to said memory means and responsive to selected stored coordinates for calculating desired changes in robot coordinates in said robot system of coordinates, and
means for displacing said robot arm in accordance with computations of said arithmetic processing means.

3 more elements

A method for controlling movement, for tracking a complex contour, of an industrial robot with an arm movable with more than one degree of freedom, and with first and second transducers for sensing deviations of said arm in a definite sensing direction for each transducer, comprising the steps of:

storing coordinates for two points defining superordinate displacement of said robot arm, in which the sensing direction of said first transducer has a component in said superordinate displacement direction;
storing coordinates for two further points defining a subordinate displacement of said robot arm in a direction which differs from said superordinate displacement direction, preferably perpendicular thereto, and coinciding with a sensing direction of said second transducer;
sensing signals produced by said second transducer, and, if said signals are below a predetermined value, displacing said robot arm in said superordinate displacement direction, and if said signals from said second transducer are above a predetermined value, changing direction of movement of said robot arm from said superordinate displacement direction to said subordinate displacement direction.

Dependencies are inferred from the claim text.

Method and means for controlling an industrial robot

Life of this patent

Method and means for controlling an industrial robot

Life of this patent

Abstract

Claims22