Method and apparatus for trajectory-planning

A computer program product comprising a non-transitory computer-readable medium having embodied thereon a computer program comprising computer program code that when executed on a computer causes the computer to plan a trajectory for an object that is capable of controlled movement in one or more degrees of freedom, planning of the trajectory comprising:

• obtaining (210) a starting state of motion of the object;
• obtaining (220) a target state of motion for the object;
• obtaining (230) one or more motion constraints;
• obtaining (240) at least one ordered sequence of movement profiles,
• wherein the at least one ordered sequence of movement profiles includes:
• (i) movement profiles that end with a phase of increasing acceleration and
• (ii) movement profiles that end with a phase of decreasing acceleration;
• evaluating (250) the at least one ordered sequence of movement profiles to determine whether they can achieve the target state of motion;
• selecting (260) a movement profile according to the result of the evaluating;
• and
• planning (270) the trajectory for the object based on the selected movement profile,
• wherein the target state of motion includes a target position, and wherein the evaluating comprises, for each movement profile in the at least one ordered sequence:
• identifying (251) the shortest travelling time that can be achieved using the movement profile;
• identifying (252) the longest travelling time that can be achieved using the movement profile;
• defining (253) a first range between the shortest travelling time and the longest travelling time;
• calculating (254) a first final position, being the final position achieved by the movement profile corresponding to the shortest travelling time;
• calculating (255) a second final position, being the final position achieved by the movement profile corresponding to the longest travelling time;
• and
• determining (256) whether the movement profile can provide one or more solutions for achieving the target state of motion, within the first range, based on the first final position, the second final position, and the target position.

A computer program product comprising a non-transitory computer-readable medium having embodied thereon a computer program comprising computer program code that when executed on a computer causes the computer to plan a trajectory for an object that is capable of controlled movement in one or more degrees of freedom, planning of the trajectory comprising:

• obtaining (210) a starting state of motion of the object;
• obtaining (220) a target state of motion for the object;
• obtaining (230) one or more motion constraints;
• obtaining (240) at least one ordered sequence of movement profiles,
• wherein the at least one ordered sequence of movement profiles includes:
• (i) movement profiles that end with a chase of increasing acceleration and
• (ii) movement profiles that end with a phase of decreasing acceleration:
• evaluating (250) the at least one ordered sequence of movement profiles to determine whether they can achieve the target state of motion;
• selecting (260) a movement profile according to the result of the evaluating;
• and
• planning (270) the trajectory for the object based on the selected movement profile,
• wherein the evaluating comprises identifying a movement profile that achieves the target state of motion at a specified time,
• and wherein the at least one ordered sequence of movement profiles includes a plurality of movement profiles each comprising or consisting of one of the two following sequences of seven phases:
• Sequence A:
• a first phase of increasing acceleration in a first time interval, a second phase of constant acceleration in a second time interval, a third phase of decreasing acceleration in a third time interval, a fourth phase of constant acceleration in a fourth time interval, a fifth phase of decreasing acceleration in a fifth time interval, a sixth phase of constant acceleration in a sixth time interval, and a seventh phase of increasing acceleration in a seventh time interval;
• and
• Sequence B:
• a first phase of decreasing acceleration in a first time interval, a second phase of constant acceleration in a second time interval, a third phase of increasing acceleration in a third time interval, a fourth phase of constant acceleration in a fourth time interval, a fifth phase of increasing acceleration in a fifth time interval, a sixth phase of constant acceleration in a sixth time interval, and a seventh phase of decreasing acceleration in a seventh time interval,
• wherein the acceleration is a piecewise linear function of time and the fourth time interval has nonzero duration.