Hi All
I have managed to model a pick and place robot, that by giving it 5 certain points in space, it can move between these points , following them very precisely!
But I needed to do an actual trajectory planning, meaning to define a path estimation, by a function! how do I do that? do I need these points too , should I interpolate the points to get a function out of them?
I also want to define a moving object, and using a vision camera, communicate with the robot to avoid that object! How is this possible in CoppeliaSim? I know there are vision sensors, accelerometers etc, but how to interact with those data and how to give those data to the robot arm and how to avoid the obstacle by defining a new trajectory?
How to do a proper trajectory planning ?
Re: How to do a proper trajectory planning ?
Why is nobody answering?
I found one post, also saying that smooth transition between trajectory points is very complicated, but I do not find a single example
I found one post, also saying that smooth transition between trajectory points is very complicated, but I do not find a single example
Re: How to do a proper trajectory planning ?
Hello,
you are asking many questions in the same post, and those questions are not trivial. Nor is it completely clear what exactly you want to do.
We do not provide help with algorithms, but rather on the tool. Usually, there are many different approaches one can take to solve a particular problem.
For simple interpolation between path points, have a look at the path related functions. Also, have a look how you can move an object along a path by studying the demo scene scenes/movingAlongAPath.ttm.
Finally, you probably want to do some path planning in order to avoid obstacles. There too, have a look at some of the demo scenes in scenes/pathPlanning/
Cheers
you are asking many questions in the same post, and those questions are not trivial. Nor is it completely clear what exactly you want to do.
We do not provide help with algorithms, but rather on the tool. Usually, there are many different approaches one can take to solve a particular problem.
How is your robot moving? Is it using IK? How do you generate the motion between the 5 points?I have managed to model a pick and place robot, that by giving it 5 certain points in space, it can move between these points , following them very precisely!
For simple interpolation between path points, have a look at the path related functions. Also, have a look how you can move an object along a path by studying the demo scene scenes/movingAlongAPath.ttm.
Finally, you probably want to do some path planning in order to avoid obstacles. There too, have a look at some of the demo scenes in scenes/pathPlanning/
Cheers
Re: How to do a proper trajectory planning ?
Thank you very much for your answer. I use the IK to calculate the link movements of robot by CoppeliaSim. I assign a movement to the tip of the robot by giving it the handle(coords?) of a new point, and using sim.rmlMoveToPosition it will directly move to that point and stop. but this is not trajectory planing. I read another post and it was said that doing a smooth movement over a trajectory in space with 5th order polynomial eqation is not possible
so my question is : How do I do that? is it possible? Should I define several points? what am I supposed to do?
so my question is : How do I do that? is it possible? Should I define several points? what am I supposed to do?
Re: How to do a proper trajectory planning ?
Imagine you have a perfectly square path. How would you drive that drajectory? If you want to exactly follow that trajectory, you either need to stop in the corners, or you will see an infinite acceleration in the joints and end-effector. This is the difficulty.
If you have a path, then you can always use the Ruckig functions (or sim.moveToConfig) to follow the path by accelerating and decelerating at the beginning/end (i.e. drive along the path using Ruckig with 1 DoF). But corners will be seeing an infinite acceleration.
Have a look at the demo scene scenes/trajectoryAndMotion/pathToTrajectory.ttt: it features several possible ways to follow a path. One of them (time-optimal trajectory, using Toppra (see the statusbar text for requirements when you start the simulation)) will do exactly what you want, but by appropriately rounding the edges.
Cheers
If you have a path, then you can always use the Ruckig functions (or sim.moveToConfig) to follow the path by accelerating and decelerating at the beginning/end (i.e. drive along the path using Ruckig with 1 DoF). But corners will be seeing an infinite acceleration.
Have a look at the demo scene scenes/trajectoryAndMotion/pathToTrajectory.ttt: it features several possible ways to follow a path. One of them (time-optimal trajectory, using Toppra (see the statusbar text for requirements when you start the simulation)) will do exactly what you want, but by appropriately rounding the edges.
Cheers