Intelligent Warehouses: Focus on the Automatic Routing and Path Planning of Robotic Forklifts Able to Work Autonomously

Robotic forklifts are gaining space in the automation of logistic systems thanks to their capacity of optimizing transportation tasks and, consequently, reducing costs. In the current scenario of extremely fast technological development the automation of logistics process is essential to improve productivity and reduce costs. In this context, mechatronics systems are replacing conventional manual operated systems and also offering new solutions for transport tasks in harbors, warehouses, storages, and product distribution centers. This chapter initially presents the state of art on routing systems applied on intelligent warehouses. Then, we present the approach used to develop our Router. The algorithm was designed to deal with real situation operation condition, such as the requirement for conflict-free paths and the capacity to avoid obstacles. This router is able to solve traffic jams and collisions, generate conflict-free and optimized paths before sending the final paths to the robotic forklifts and verifies the progress of all tasks. When a problem occurs, the Router can change the tasks priorities, routes, etc. in order to avoid new conflicts. In the routing simulations each vehicle executes its tasks starting from a predefined initial pose (position and orientation), moving to the desired pose (destination node). The algorithm is based on Dijkstra's shortest-path method and was implemented in C language. We also tested two different approaches in order to find the best navigator for our application: A* Algorithm and Potential Fields method. Computer simulation tests were used to validate the algorithm efficiency under different working conditions. Several simulations were carried out using the Player/Stage Simulator to test the algorithms. As a result, we could solve many bugs and refine the algorithms before on boarding the algorithms in real robots. The EKF filter was sufficient to avoid the position error propagation.

Keywords: Routing Algorithm, Path Planning, Robotic Forklifts, Mobile Robotics, Intelligent Systems