The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 1996
Filed:
Feb. 13, 1995
John-Erik Snell, Vaster.ang.s, SE;
ASEA Brown Boveri AB, Vaster.ang.s, SE;
Abstract
A method for controlling an industrial robot such that a tool supported by the robot is able to follow a path which is determined by a number of consecutive points, and wherein the robot while following the path ends up near or a singularity. The robot has a plurality of movement axes and its configuration is determined by the angles of rotation of the movement axes. The angles of rotation which are to be assumed by the robot in order to obtain the desired position and orientation for the tool at the next point on the path are calculated by an iterative method. The ratio of the angular velocities of the axes to the velocity of the tool is given by a Jacobian matrix. By means of the Jacobian matrix it is determined whether the robot is at or near a singularity. The intention of the invention is to control the iteration such that the position of the tool remains correct through the singularity. A certain error in the orientation of the tool may be accepted. At a singularity the importance of the position errors is increased by weighting these errors during the iteration in relation to the orientation errors while at the same time locking the singular axes.