how to handle multiple way-points for 2D path following

I am trying to generate a path following profile from multiple way-points that I generated from path planning. My path following algorithm is in a MatLab function within a Simulink model which includes a controller and a simple kinematic model. I can run the Simulink model each time for one pair of successive way-points and get a sensible path between these successive way-points, but am struggling to feed in all 'pairs' of waypoints through the simulation and get an xy profile of the whole path. Am I approaching this problem from the correct angle ie asking the controller to calculate a path between each successive pair of way-points and plot the overall profile.

[Jacob Wood]

It seems like you have a good portion of a solution worked out. The next step would be to find a way to do the handoff from solution to solution. The simplest answer might just be a for-loop that looks at each succesive pair of points, finds the path, pulls out relevant information for the next section (terminal velocity vector, maybe terminal accelerations), and feed that into the next pair.

If you wish to implement in Simulink it is common practice to implement a waypoint radius. When the vehicle is within waypoint_radius of the current waypoint it runs the path generation algorithm for the next leg of the journey and starts to navigate to this next waypoint.

[William Campbell]

Hello Jacob,

thanks for your comments - I have been struggling with the for-loop within the MatLab function script but don't seem to be getting too far. I get the 1-D input vectors of my way-points into the function script from the workspace and the first set of way-points flow through the algorithm calculations and output the variables to the controller and kinetic model in Simulink. But I am not able to get the for-loop to create an x-y matrix once the current x-position is close to the x-position of the second way-point, reset the initial conditions of the kinematic model and advance to the next pair of way-points. I believe there is a Robotic toolbox on later MatLab versions but these are later than the version I am using (R2017a). Do you know of any example scripts that I could look at in R2017a ?

Answer 1

[Amrtanshu Raj]

Hi,

As per my understanding you have a set of waypoints and want to get a path through those points. You can use the purePursuit controller and step it to get a complete path. It also lets you add constraints to the motion.

[William Campbell]

Hello Amrtanshu,

thank you for your comments - I'll take a look.