Patent ID: 8825207
Filing Date: 2014-09-02
Classification: B25J,G05B

Abstract:
1. A trajectory planning method for determining a trajectory for controlling a state of a target device from an initial state toward a goal state, the method performed by a computer in a trajectory planning system, and the method comprising steps of: dividing a state space of the device into cells; generating, from a position in the state space indicative of the initial state to a cell containing a position indicative of the goal state, a search tree having at least one branch, each branch having a first node and a second node and each node indicating a respective state of the device, in such a way that each cell does not contain more than one node, the second node indicating the state after a state transition from a first state corresponding to the first node, the state transition occurring due to an input given to the device at the first state; and determining a path from the initial state to the goal state of the device by determining a set of the branches of the search trees connecting the initial state with the goal state, wherein, in the step of dividing the state space, an approximation error of each of the cells is calculated and the state space is divided into a predetermined number of cells such that a sum total of the approximation error over all the cells is minimized, and wherein the approximation error is defined as a size of distribution of a group of states in the state space after state transitions from a group of states within the corresponding cell, said state transition occurring due to applying a group of possible inputs to the group of states within a corresponding cell.