A method and apparatus for controlling a manipulator

Claim 3

The method claimed in claim 1 including the steps of dividing said programmed path into straight line increments of predetermined equal time duration, moving said tool center point via said control in said increments, when a vision data point is received and is offset from said programmed path moving said tool along a vector from its last position toward said vision data point in said increments until it is within less than one said increment of said vision data point, thereafter moving said tool along a vector from this position toward the next vision data point in said increments until it is within less than one said increment thereof, and repeating this procedure to cause said tool to track said seam.

Claim 4

The method claimed in claim 2 including the step of disregarding a vision data point the scan of which was not spaced from the scan of the previous vision data point by at least a predetermined distance.

Claim 5

The method claimed in claim 2 including the step of disregarding a vision data point if it is not spaced from the present position of the tool by more than twice said increment.

Claim 6

The method of claim 2 including the step of adjusting the position of a vision data point to have new coordinates in the manipulator coordinate system if its distance from the present position of the tool exceeds a predetermined value.

Claim 7

The method claimed in claim 3 including the step of disregarding a vision data point if it is not spaced from the present position of the tool by more than twice said increment.

Claim 8

The method of claim 4 including the step of adjusting the position of a vision data point to have new coordinates in the manipulator coordinate system if its distance from the present position of the tool exceeds a predetermined value.

Claim 9

A function element having a tool center point associated therewith and apparatus for moving said tool center point along a seam in a plurality of substantially identical workpieces wherein the seam of each workpiece may deviate slightly from that of the next workpiece, said apparatus comprising a manipulator of the type having a plurality of movable members and actuators for effecting motion of said members, said function element being mounted on said manipulator, a manipulator control including a servo mechanism circuit connected to said actuators to operate said members and move said function element and its tool center point along a programmed path corresponding to said seam at programmed velocities and at programmed dynamically varying orientation angles, means mounted on said manipulator ahead of said tool center point for identifying and scanning said seam at predetermined intervals, means for deriving a set of coordinates for the center point of said seam for each scan in a coordinate system relative to said scanning means, said manipulator members being movable in a coordinate system relative to said manipulator, said sets of coordinates comprising vision data points, means for transforming said sets of scanning means coordinates to said coordinate system of said manipulator using transformation matrices employing the orientation angles in effect at the time of the scan for the camera coordinates being transformed, means for supplying at least selected ones of said vision data points to said control, and means in said control for using said vision data points to alter said programmed path as required to move said tool center point along said seam.

Claim 10

A function element having a tool center point associated therewith and apparatus for moving said tool center point along a seam in a plurality of substantially identical workpieces wherein the seam of each workpiece may deviate slightly from that of the next workpiece, said apparatus comprising a manipulator of the type having a plurality of movable members and actuators for effecting motion of said members, said function element being mounted on said manipulator, a manipulator control including a servo mechanism circuit connected to said actuators to operate said members and move said function element and its tool center point along a programmed path corresponding to said seam at programmed velocities and at programmed dynamically varying orientation angles, means mounted on said manipulator ahead of said tool center point for identifying and scanning said seam at predetermined intervals, means for deriving a set of coordinates for the center point of said seam for each scan in a coordinate system relative to said scanning means, said manipulator members being movable in a coordinate system relative to said manipulator, said sets of coordinates comprising vision data points, means for transforming said sets of scanning means coordinates to said coordinate system of said manipulator using transformation matrices employing the orientation angles in effect at the time of the scan for the camera coordinates being transformed, means for supplying at least selected ones of said vision data points to said control, and means in said control for using said vision data points to alter said programmed path as required to move said tool center point along said seam.

Claim 11

The apparatus claimed in claim 8 wherein said control includes means to divide said programmed path into straight line increments of predetermined equal time duration, said control includes means to generate signals to said servo mechanism circuit to move said tool center point in said increments, said control, when a vision data point is received and is offset from said programmed path, having means to calculate a vector from the tool center point's last position toward said vision data point and to move said tool center point along said vector in said increments until it reaches a position within less than one said increment of said vision data point, and thereafter to calculate a new vector from said last mentioned position to the next vision data point and to move said tool center point along said new vector in said increments until it reaches a position within less than one said increment thereof, and to calculate subsequent vectors and to move said tool center point therealong in said increments whereby to cause said tool center point to track said seam.

Claim 12

The apparatus claimed in claim 8 including means to disregard a vision data point the scan of which is not spaced from the scan of the previous data point by at least a predetermined distance.

Claim 13

The apparatus claimed in claim 8 including means to disregard a vision data point if it is not spaced from the present position of said tool center point by more than twice said increment.

Claim 14

The apparatus claimed in claim 8 including means for adjusting the position of a vision data point to have new coordinates in said manipulator coordinate system if its distance from the present position of said tool center point exceeds a predetermined value.

Claim 17

The method according to Claim 1 further characterized in that the rate of deviation between the path followed by the tool centerpoint and the expected path defined by the program is limited in accordance with a limit value set by an operator.

Claim 18

The method of Claim 2 wherein the distance between points represented by path point signals is dependent on the velocity of the scanner/camera head relative to the workpiece feature and the scanning rate and the method is further characterized in that the points represented by the selected transformed path point signals are at least a predetermined distance one from another.

Claim 19

The method of Claim 3 further characterized in that: (a) an increment distance is calculated defining an increment through which the tool centerpoint will move in a predetermined time; and (b) each point represented by a selected transformed path point signal is spaced from the current tool centerpoint location at the time of selection by at least twice the increment distance.

Claim 20

The method of Claim 4 further characterized in that motion of the tool centerpoint toward a point represented by selected transformed path point signals is effected in a series of moves each of which is the . calculated increment distance in length.

Claim 23

The apparatus of Claim 6 further characterized in that means are provided to limit the rate of deviation of the path followed by the tool centerpoint from the expected path defined by the program in accordance with a limit value set by an operator

Claim 24

The apparatus of Claim 7 wherein the distance between points represented by path point coordinates is dependent on the velocity of the scanner/camera head relative to the workpiece feature and the scanning rate and the apparatus is further characterized in that the means for selecting transformed path point coordinates selects the transformed path point coordinates which represent points which are at least a predetermined distance one from another.

Claim 25

The apparatus of Claim 8 further characterized in that: (a) means are provided to calculate an increment distance defining an increment through which the tool centerpoint will move in a predetermined time; and (b) the means for selecting transformed path point coordinates selects transformed path point coordinates which are spaced from the current tool centerpoint location at the time of selection by at least twice the calculated increment distance.

Claim 26

The apparatus of Claim 9 further characterized in that the means for effecting motion of the tool centerpoint in response to selected transformed path point coordinates produces a series of moves each of which is the calculated increment distance in length.