Modeling and path planning of the City-Climber robot part II: 3D path planning using mixed integer linear programming

This is the second part of a series papers on modeling and path planning of the City-Climber robot. This paper presents a path planning method for the City-Climber robot using mixed integer linear programming (MILP) in 3D building environments that consist of objects with primitive geometrical shapes. In order to use MILP to solve obstacle avoidance problems, we first simplify and decouple the robot dynamic model by introducing a restricting admissible control. The decoupled model and obstacle can be rewritten as a linear program with mixed integer linear constraints that account for the collision avoidance. A key benefit of this approach is that the path optimization can be readily solved using the AMPL and CPLEX optimization software with a Matlab interface. Simulation results show that the framework of MILP is well suited for path planning and obstacle avoidance problems for the wall-climbing robot in 3D environments.