Self-learning PD algorithms based on approximate dynamic programming for robot motion planning

Motion planning is a key technology of the navigation and control for mobile robots. However, when considering the complexity of exterior environment and mobile robot´s kinematics and dynamics, the motion planning results obtained by some traditional methods are often hard to optimize. In this paper, we propose two self-learning PD algorithms to solve motion planning for mobile robots. We firstly utilize a virtual Proportional Derivative (PD) control strategy to transform the motion planning problem into an optimization problem of the virtual control policy. Afterwards, two approximate dynamic programming algorithms, which are the Least Squares Policy Iteration (LSPI) algorithm and the Dual Heuristic Programming (DHP) algorithm, are incorporated into the virtual control strategy to tune the PD parameters automatically, namely the LSPI-PD algorithm and the DHP-PD algorithm. Simulations have been performed to validate the effectiveness of the two algorithms, where the LSPI-PD algorithm is suitable for solving problems with discrete action spaces while the DHP-PD algorithm has an advantage in solving problems with continuous action spaces.