Given a global reference trajectory \(\mathbf{z}_{ref}^{\langle t-\infty, t+\infty \rangle}\), CyC GraphPlan calculates a safe trajectory and control signals for the robot, while avoiding the obstacles found along this reference path.
The figure below shows CyC GraphPlan controlling an aerial vehicle along a reference trajectory (green) and the block diagram of the planning and control system. The method uses CyC GraphSense and the underlying robot state \(\mathbf{x}^{\langle t \rangle}\) to generate feasible trajectory candidates in the 3D Cartesian space.
Each candidate trajectory is evaluated using a cost function that penalizes obstacle collisions and the distance between each candidate waypoint and the given global reference path. The optimization loop simultaneously calculates the best (desired) trajectory \(\mathbf{z}_{d}^{\langle t+1, t+N \rangle}\) and the control signals \(\mathbf{u}^{\langle t \rangle}\) which would execute the robot's motion along \(\mathbf{z}_{d}^{\langle t+1, t+N \rangle}\). \([t+1, t+N]\) is the time interval for which the generated trajectories are calculated, encoding their length.
Path planning and motion control in Autonomous Ground Vehicles (AGV)
Path planning and motion control in Aerial Vehicles (Drones)