Temporal Potential Function based Path Planner for Dynamic Environments

Simulates the Temporal Potential Function approach for Path Planning in Dynamic Environments

Description

A Dynamic environment is one in which either the obstacles or the goal or both are in motion. In most of the current research, robots attempting to navigate in dynamic environments use reactive systems. Although reactive systems have the advantage of fast execution and low overheads, the tradeoff is in performance in terms of the path optimality. Often, the robot ends up tracking the goal, thus following the path taken by the goal, and deviates from this strategy only to avoid a collision with an obstacle it may encounter. In a path planner, the path from the start to the goal is calculated before the robot sets off. This path has to be recalculated if the goal or the obstacles change positions. In the case of a dynamic environment this happens often. One method to compensate for this is to take the velocity of the goal and obstacles into account when planning the path. So instead of following the goal, the robot can estimate where the best position to reach the goal is and plan a path to that location. In this package, we simulate a such a method for path planning in dynamic environments. The method uses a potential function approach that considers time as a variable when calculating the potential value. This potential value for a particular location and time indicates the probability that a robot will collide with an obstacle, assuming that the robot executes a random walk from that location and that time onwards. The robot plans a path by extrapolating the object’s motion using current velocities and by calculating the potential values up to a look-ahead limit that is determined by calculating the minimum path length using connectivity evaluation and then determining the utility of expanding the look-ahead limit beyond the minimum path length. The method is fast, so the path can be re-planned with very little overhead if the initial conditions change at execution time.

• MATLAB release: MATLAB 7.5 (R2007b)

[Reza]

I have problem with pointer in Data Structures and Algorithms Toolbox with the following message:
??? Invalid MEX-file 'C:\...\@POINTER\pointer.dll':
C:\...\@POINTER\pointer.dll is not a valid Win32 application.
How can I solve it?

[Vamsikrishna Gopikrishna]

You also need to use the pointer library provided at

http://code.google.com/p/pointer/

[shanghai ²²]

How can I check this algorithm?should I initialize the W and obs matix？I can read clear about your program.while there is on a main function to ord all the functions

[Saravana]

How can I simulate this program? What r the inputs I need to give? which is the main function?

[Patrik Eschle]

This *may* be a wonderful path planner. However, it is of no practical use, since the function arguments are not documented.

It is a little effort to describe input and output parameters, add an example and make error messages descriptive. Matlab itself gives the best examples on how to to do this.