Path Planning with A* and RRT | Autonomous Navigation, Part 4

[@josephma5961]

Your videos on Control system actually inspired to love control systems even after a terrible experience in College Course. Now you are again Doing wonders... How do you explain things like these so gracefully. Great work... Pretty sure youve got many total beginners like me hooked up to this series.

[@BrianBDouglas]

That’s great to hear that you’re finding this interesting. Thanks for the wonderful comment. :)

[@reshmasuresh6613]

@@BrianBDouglas Hey Brian, great content! I just have a doubt. So, if RRT* is run for fairly enough iterations for a known domain, near optimal path can be achieved within any two nodes?

[@dbsh4302]

This video is soooo great for beginners like me interested in path planning. Thank you for making and sharing this video!

[@Drone.Robotics]

I always feel amazed after watching your videos...keep it up.

[@luke7503]

I love how the recommended Sebastian lague his channel is amazing

[@thanishkumar398]

Thank you, Brian, for this great video. It was really insightful in starting to learn about path planning : )

[@MrEdnz]

Yo brian, these videos really are wonderfully made. As a control systems undergraduate these help me refresh my memory. Keep up the good work!

[@BrianBDouglas]

I will try! Thanks :)

[@jainilsheth9879]

Thanking for this video, was a great introduction!!!

[@rkspprakhya5944]

Wow you made my engineering interesting...

[@usamazaheer3109]

Hi can u give me your instagram

[@kalebakeitshokile1366]

You made my final year project a lot easier. I'm currently doing a comparison on implementations of D*, A* and maybe Dijkstra in python that I will hopefully (depending on COVID) run on a robot to.

[@kalebakeitshokile1366]

Just submitted the final report. Unfortunately wasn’t able to run the code on the robot but D* absolutely destroyed A* when it came to replanning 😂

[@mdshahriarkabir4731]

@@kalebakeitshokile1366 Did you succeed?

[@kalebakeitshokile1366]

@@mdshahriarkabir4731 i did pretty well in the end. I’ve made improvements to the code since then too. Didn’t get to use the robot because of covid though

[@pratyushkumar2843]

you are just phenomenal ❤

[@kartikjain4835]

amazing explanation with animations really Helpful 🤩🤩🤩😀

[@spiritfly8210]

Thanks for sharing the video.

[@bheemavarapuvardhan9382]

Please make a video on path planning using MATLAB by A* algorithm

[@Buyson]

So, if I understand correctly in rrt we have access to whole state space. You mentioned it is useful for high dimensional state spaces and that we do not add to the tree in case of collision with the surroundings, but here is a question, isn't it quite hard to calculate whether there is a collision in a reasonably high dimensional state space (especially if there are many surroundings)?

[@BrianBDouglas]

I suppose it can be difficult to test for a collision in general, but RRT and RRT* require a map of the environment - and obstacles. So, with a perfect map of the environment, there are many ways to test for collisions between a path and the obstacles in the map. If your map is an occupancy grid, then you just check to see if each cell along the path is free or not. If your map is in a different form, then other collision algorithms could be used - one example is the separating axis theorem. But again, these work because you have a good map of the obstacles. Without that, then the problem becomes tougher because you have to find a way to sense obstacles real time and make a new plan to avoid them. I hope this answered your question!

[@Buyson]

@@BrianBDouglas I was imagining a map with many collisions (~50% filled with completely random collision placement), so it would be quite hard to even reject sample the next node to the tree but now I think it is not that realistic to have such a map. Thanks for returning Brian, big fan!

[@mohdalkhasawneh3570]

in this case, we know the initial and final position right?

[@igoragoli]

Thanks a lot for the video!

[@countonmekaron]

can i get that code? rrt *

[@vdengineering2666]

Amazing thank you

[@KIXEMITNOG]

Can you implement a Linear-Quadratic-Regulator on a line follower?

[@BrianBDouglas]

That is a good idea. I’ll add it to the list but it’ll be awhile. My video schedule is planned for the rest of this year. Thanks for the suggestion.

[@aayushanand4687]

is there any code for that available?

[@BrianBDouglas]

If you're looking for examples using RRT in MATLAB, check out the first two links in the additional resources section of the description.

[@bryanblaise79]

Hi Brian, what software was used to create this presentation? For the portion where you were writing in various colors.

[@gmlcks1908]

I'm using Arduino and reading values by setting codes in Arduino and simulate on Matlab. I need to find a way for a robot(from start) to find a goal and get back to its original position just exactly like what you have explained in this video. I understand the logic you are explaining but wonder how would I write codes and commit to the navigation simulator if you have any idea please let me know

[@boylanpardosi4586]

I dont use matlab that often, but I've got a problem that require route planning in large scale grid. The build in path planner solve real fast where astar python implemented cant solve for hours

[@BrianBDouglas]

Do you know if it's using A*? Also, do you know if it's solving an optimal path or just a viable path?

[@lilburger4274]

How does the robot know where the start and end is?

[@EngineeringSimplified]

By using SLAM first to create a map of the environment.

[@samuraismack]

Thanks for the great content. I'm looking into an application wherein I need to determine whether there exists a path for an object of finite irregular shape to fit into a cavity with that same shape. Would you have any recommendations for algorithms which might be suited to this?

[@myronrayner9815]

great content)

[@parmardipti9186]

Which software you use for drawing and teaching? Nice work though 👍

[@BrianBDouglas]

I explain it here: engineeringmedia.com/my-setup

[@mouryat_liv]

@@BrianBDouglas Your animations are pretty simple and cool !! I know videos can be overlaid as picture in picture, but how about animations and how do you make them? Is it Illustrator?

[@BrianBDouglas]

@@mouryat_liv The animations are made in Final Cut Pro. I don't do anything too involved with animations. Mostly just set the position, scale, and rotation at one keyframe and then the same at another keyframe and let Final Cut interpolate between the two. Whenever the animations look like MATLAB plots it's because I coded then in MATLAB :) Then I just export a movie from the script and pull it into the video. Cheers!

[@mouryat_liv]

@@BrianBDouglas Wow, thanks for the reply! I'm going to frame this :D Your lectures are the best, seen them countless times since my undergrad and will see them throughout my Phd and later.

[@BrianBDouglas]

@@mouryat_liv Thanks! Best of luck with your Phd and beyond.

[@oldcowbb]

rrt* literally looks like trees triying to grow roots to the nearest water source

[@error8542]

Input output of Robot path planning????

[@SurajBorate-bx6hv]

input : start point , goal point, obstacles output: path and tree(in case of rrt)