Method and device for determining a time-optimal trajectory

1 . A computer-implemented method for controlling an industrial robot by determining a time-optimal trajectory before a start of movement for a movement of the industrial robot predefined by movement parameters on a path defined by path parameters which have at least a start point and an end point and comprise at least one path type, in compliance with predetermined limits, the method comprising the steps of:

dividing the path into one or more partial paths comprising a geometrically spatially defined partial path and a geometrically spatially free partial path;

performing a predetermined number of repetitions of the following steps:

for the geometrically spatially defined partial path, calculating a time-optimal trajectory for each of the geometrically spatially defined partial paths according to one or more methods for calculating geometrically spatially defined partial paths in consideration of the predetermined limits and applicable path and movement parameters, and selecting the best result of the methods for the respective partial path;

for the geometrically spatially free partial path, calculating a time-optimal trajectory for each of the geometrically spatially free partial paths according to one or more methods for calculating geometrically spatially free partial paths in consideration of the predetermined limits and applicable path and movement parameters, and selecting the best result of the methods for the respective partial path;

merging the time-optimal trajectories for all of the geometrically spatially defined partial paths that are selected as the best result of the methods for the respective partial paths and for all of the geometrically spatially free partial paths that are selected as the best result of the methods for the respective partial path into one overall trajectory;

checking that the overall trajectory does not exceed the predetermined limits and allows the thus far fastest movement along the path;

varying one or more of the movement parameters for the geometrically spatially defined partial path and for the geometrically spatially free partial path;

following completion of the predetermined number of repetitions, outputting the fastest overall trajectory to a robot control device for the industrial robot as the time-optimal trajectory for movement along the path; and

moving the industrial robot along the time-optimal trajectory using the robot control device.

2 . The method according to claim 1 ,

wherein the method for calculating geometrically spatially defined partial paths is selected from the following group: a method for optimising a route parameter in a time range and a method for optimising a route parameter in a velocity range.

3 . The method according to claim 1 , wherein the partial paths comprise at least one of

a geometrically spatially defined partial path,

a geometrically spatially free partial path and

a geometrically spatially defined partial path and a geometrically spatially free partial path.

4 . The method according to claim 1 , wherein the path parameters further comprise grid points which represent connection points of two partial paths or points within one or more paths.

5 . The method according to claim 1 ,

wherein the movement parameters comprise velocity and/or acceleration values, and/or

wherein the movement parameters comprise values which are to be applicable at grid points, the start point and/or the end point; and/or

wherein the path parameters comprise one or more grid points, further path types of partial paths, and a maximum velocity of partial paths.

6 . The method according to claim 1 , further comprising a dual cycle of a performance of a predetermined number of repetitions of the method steps,

wherein during a first cycle, only a velocity movement parameter is varied when varying one or more of the movement parameters, and

wherein during a second cycle, acceleration and velocity movement parameters are varied when varying one or more of the movement parameters.

7 . The method according to claim 1 , wherein the limits describe physical limits which must not be exceeded or fallen short of in one or more joints and/or drive axles of the industrial robot.

8 . The method according to claim 1 , wherein the limits comprise one or more of the following values: a position, an acceleration, a jerk, axle speed per axle of the industrial robot, a motor torque per axle of the industrial robot, and a path velocity.