Path planning and collision avoidance for multiple autonomous robots in static environment.

Question

I am going to start my work on a robotic project. Before jumping into the question, let me first give a brief description of the set up of this project.

The set up consists of a facility where there is a rail system and there are multiple robots mounted on them. The environment is static with only mobile robots. As for now it can be 3 robots wagon on these rails. These robots are for pick-and-place tasks.There is, as such no communication between these robots but they are connected to the server, which gives the robots tasks.

Please have a look at the rough sketch (pardon me for this bad diagram) to have an idea of the set-up.

From the above diagram, R1 and R2 are robots on the rails. The server may assign a job to robot R1 for picking an object at "A" and dropping it at "B" and the robot has to move completely autonomous. Now, my queries are as follows:

• How the robot R1 moves to "A" and then to "B", taking the optimal path, concerning Path Planning of the robot?
• How the robot avoid collision in a static map, with other mobile robots on the rails, concerning collision avoidance ? (I am thinking of using a camera to detect the other robot)

I have looked into some literature and have a basic idea. I have also gone through some of the asked question in here. But I dont have any concrete idea to start working. I am looking for some advice/ideas/algorithms/literature to go about the problem. Please help me out. Thanks in advance !!

Note: I will be simulating the whole set-up in a 3D environment.

Answer 1

For the first question, consider the entire rail network as a graph and use a shortest path algorithm to get the optimal path.

I do not know if you are allowed to move other robots when moving R1 to A and B. If some of the robots cannot be moved, then remove those portions of the railway from the graph, and calculate the path.

To avoid collision, one method would be to allow motion in only one direction along the rails (a figure of 8 in this case). Overall it should not be a problem since you are controlling the bots from a central server.