US 11,673,271 B2
Trajectory generation apparatus, multi-link system, and trajectory generation method
Kenichi Minoya, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Feb. 3, 2021, as Appl. No. 17/166,817.
Claims priority of application No. JP2020-018237 (JP), filed on Feb. 5, 2020.
Prior Publication US 2021/0237270 A1, Aug. 5, 2021
Int. Cl. B25J 9/16 (2006.01); B25J 13/08 (2006.01)
CPC B25J 9/1666 (2013.01) [B25J 9/163 (2013.01); B25J 9/1607 (2013.01); B25J 13/089 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A trajectory generation apparatus configured to generate a trajectory of a multi-link mechanism in a motion space, the multi-link mechanism being a machine mechanism in which a plurality of links are connected by joints that are movable parts,
the trajectory generation apparatus comprising:
an information acquisition unit configured to acquire obstacle information regarding a position of an obstacle existing in the motion space of the multi-link mechanism;
an end position estimation unit configured to estimate a next end position that is an end position at a second time that is a time next to a first time, the end position being a position of an end effector of the multi-link mechanism,
based on (i) a subject joint state of the multi-link mechanism at the first time, (ii) a target joint state of the multi-link mechanism, and (iii) the obstacle information acquired by the information acquisition unit,
by using a learning result of a machine learning in which
a start joint state of the multi-link mechanism, a goal joint state of the multi-link mechanism, and the obstacle information are input and
the end position being the position of the end effector of the multi-link mechanism is output; and
a restriction search unit configured to search for a non-interfering joint state of the multi-link mechanism, in which the obstacle and the multi-link mechanism at the second time do not interfere with each other, while considering as a restriction the next end position estimated by the end position estimation unit, wherein:
the restriction search unit is configured to include:
an end orientation generation unit configured to generate an end orientation that is an orientation of the end effector to take the next end position estimated by the end position estimation unit;
a joint state obtainment unit configured to obtain a joint state of the multi-link mechanism satisfying the next end position estimated by the end position estimation unit and the end orientation generated by the end orientation generation unit; and
an interference determination unit configured to determine whether an interference is present between the obstacle and the multi-link mechanism that takes the joint state obtained by the joint state obtainment unit,
wherein:
in response to the interference determination unit determining that the interference is not present, the restriction search unit is configured to end searching for the non-interfering joint state; and
in response to the interference determination unit determining that the interference is present, the restriction search unit is configured to determine whether a counted number of times of end orientation generation, which is a counted number of times the end orientation is regenerated by the end orientation generation unit, is less than or equal to a specified number,
wherein:
in cases that it is determined that the counted number of times of end orientation generation is less than or equal to the specified number in response to the interference determination unit determining that the interference is present,
the end orientation is regenerated into a different end orientation by the restriction search unit with the end orientation generation unit, and searching for the non-interfering joint state is continued by the restriction search unit, and
in cases that it is determined that the counted number of times of end orientation generation is greater than the specified number in response to the interference determination unit determining that the interference is present,
searching for the non-interfering joint state while considering as the restriction the next end position is discontinued by the restriction search unit,
the next end position is re-estimated into a different next end position by the end position estimation unit, and
then searching for the non-interfering joint state while considering as the restriction the different next end position is re-started by the restriction search unit.