Robot path planning method where bending owing to load is taken into consideration

A robot path planning method using a robot controller, in which bending of a plurality of axes each having an axial value of a robot owing to load is taken into consideration, comprising steps of:

• (a) determining bending amount of each axis at a starting point and at an ending point, based on a position data of said starting point and a position data of said ending point and a load parameter of the robot, which bending amount is added to each axial value corresponding to said position data of said starting point and said position data of said ending point, to determine each axial value corresponding to a position of said starting point and a position of said ending point, in which bending is taken into consideration for at least one section to which said position data of said starting point and said position data of said ending point are given;
• (b) determining bending amount of each axis relating to said starting point and said ending point, based on said each axial value in which bending is taken into consideration and said load parameter of the robot;
• (c) determining a plurality of corresponding coordinate values of the position of said starting point and of the position of said ending point of the robot, based on each axial value in which bending is taken into consideration as determined in step (a);
• and determining positions of a plurality of interpolation points on the robot path connecting the starting and ending points given by the coordinate values,
• (d) determining said bending amount of each axis relating to said positions of each interpolation point based on said bending amount relating to said starting point and said ending point as determined in step (b);
• and
• (e) determining each coordinate value of each interpolation point as the data which represent target positions for a sequential movement, by calculating each axial value corresponding to an interpolation point based on said positions of said interpolation points, and subtracting said bending amount at each interpolation point as determined in step (d) from each of said calculated axial value.

A method of compensating deviations of robot movement due to varying loads placed on a robot, comprising:

• 1) determining a first traveling path from a starting position to an ending position of a robot that has not been loaded with robotic tools;
• 2) determining a second traveling path from said starting position to said ending position of a robot that has been loaded with robotic tools;
• 3) determining amount of displacements between said first traveling path and said second traveling path;
• 4) determining an amount of angular adjustment to a plurality of axes of said robot that has been loaded with robotic tools so that it travels along said first traveling path.