Path planning apparatus of robot and method and computer-readable medium thereof
An apparatus, method and computer-readable medium planning a path of a robot by planning an optimal path while satisfying a dynamic constraint. In a process of searching for a motion path from a start point to a goal point while extending a tree from a start point of a configuration space to generate a path, along which a manipulator of the robot is moved in order to perform a task, an optimal path is generated responsive to the dynamic constraint of the manipulator of the robot to generate stable motion satisfying momentum and Zero Moment Position (ZMP) constraint. Accordingly, path planning performance is improved and a path satisfying a kinematic constraint and a dynamic constraint is rapidly obtained.
1. A method of planning a path of a robot, the method comprising:
recognizing, by at least one processor, a start point and a goal point respectively corresponding to an initial configuration and a goal configuration of a manipulator of the robot;
estimating, by the at least one processor, a dynamic constraint of the manipulator of the robot;
searching, by the at least one processor, in configuration space for a path satisfying a constraint including obstacle avoidance from the start point to the goal point; and
generating, by the at least one processor, a path satisfying the dynamic constraint from the searched path,
wherein the dynamic constraint relates to at least one of speed and balance.
2. The method according to claim 1 , wherein the dynamic constraint is set to a Center Of Gravity (COG) and one of a Zero Moment Position (ZMP) of the robot and an experimentally obtained momentum value.
3. The method according to claim 1 , wherein the searching of the path includes:
connecting a certain point randomly sampled in configuration space having the start point and the goal point and a node having a smallest goal score to obtain a sample g new satisfying the constraint;
adding the sample g new to the tree to extend the tree until the sample g new reaches the goal point; and
searching for the path to connect the start point and the goal point by the extension of the tree.
4. The method according to claim 3 , wherein the generating of the path includes:
projecting the sample g new responsive to the dynamic constraint;
adding a projection sample g projected to the tree to generate a search graph to extend the tree; and
connecting the start point and the goal point using the search graph to generate the path responsive to the dynamic constraint.
5. The method according to claim 4 , wherein the projecting of the sample g new includes:
checking whether a Center Of Gravity (COG) of the robot is within a supporting polygon to determine whether the sample g new satisfies static stability; and
enabling a Zero Moment Position (ZMP) of the robot to fall within the supporting polygon to satisfy the dynamic stability of the robot.
6. The method according to claim 5 , wherein the dynamic stability of the robot is satisfied by enabling the COG and the ZMP of the robot to fall within the supporting polygon to maintain balance of the robot.
7. An apparatus planning a path of a robot, the apparatus comprising:
a recognizer configured to recognize a start point and a goal point respectively corresponding to an initial configuration and a goal configuration of a manipulator of the robot; and
a path planning generator configured to form a configuration space to generate a motion path of the manipulator of the robot, to estimate a dynamic constraint of the manipulator of the robot in the configuration space, to search for a path in the configuration space which avoids an obstacle, and to generate a path to connect the start point and the goal point responsive to the dynamic constraint from the searched path,
wherein the dynamic constraint relates to at least one of speed and balance.
8. The apparatus according to claim 7 , wherein the path planning generator connects a certain point randomly sampled in the configuration space and a node having a smallest goal score to obtain a sample g new satisfying a constraint including obstacle avoidance, projects the sample g new responsive to the dynamic constraint, and adds a projection sample g projected to a tree to extend the tree.
9. The apparatus according to claim 8 , wherein the dynamic constraint is set to a Center Of Gravity (COG) and one of a Zero Moment Position (ZMP) of the robot and an experimentally obtained momentum value.
10. The apparatus according to claim 8 , wherein the path planning generator checks whether a Center Of Gravity (COG) of the robot is within a supporting polygon to determine whether the sample g new satisfies static stability, and projects the sample g new to satisfy dynamic stability of the robot if the sample g new satisfies the static stability.
11. The apparatus according to claim 10 , wherein the dynamic stability of the robot is satisfied by enabling the COG and a Zero Moment Position (ZMP) of the robot to fall within the supporting polygon to maintain balance of the robot.
12. At least one non-transitory computer readable medium comprising computer readable instructions that control at least one processor to implement the method of claim 1 .