A trajectory generator for a mobile robot in 3D pathplanning

A method for computing a trajectory motion for a mobile robot is described. When robot moving in 3D environment, a original trajectory composed by a serial of line segments is generated throughout the safely moving area to ensue the robot avoid the obstacles. This area is computed by size of the robot and path space. Then, a smooth procedure is introduced to be connected the segments by symmetric clothoid curves at the junction of two lines. The procedure uses turn angle, the constant turn acceleration and linear velocity to calculate the location of clothoid curves, which allow the robot to continuously change the direction of motion and the angular speed. However the smooth trajectory may be splice or out of the safely moving area. Therefore the motion restrict equations are presented to compute the required linear velocity and turn acceleration in real time. The result of simulation proves the feasibility and validity of this new method.