determinate trajectories and speed

Hello, I'm working on a problem and i would like to know is mathlab could help me. From a car main trajectory and reference speed, i would like to determinate all the possible trajectories (integreting reference speed on the main trajectory, mass of the car etc...)for each main trajectories points and for each sub-trajectory, the speed on each sub-trajectories points. Thank you for your help

[Jan]

The question is not clear. What are the available inputs? What is a main trajectory? What is the reference speed? How the "all possible trajectories" related to the mass of the car? What is "etc. here? What is a sub_trajectory?

If it can be computed, it can be computed by Matlab also. But would a "yes" be a satisfying answer for you?

[eric]

Hello Jam Simon and thank you for your a answer. You drive a car ( you know his dimensions, his weight, the tyres, the turning circle possibilities). You register the real time trajectory and speed. This is the reference. You take one point on this trajectory. You know the reference speed on this point. From this point with all the information, i would like determinating all the trajectories based on the physical laws

[Walter Roberson]

I am not certain you mean "trajectories"; I think you might mean "velocities", or perhaps you want to analyze the various forces acting on the car at each point (which would require knowing the tire friction and the transition point at which adhesive friction fails.)

[John Petersen]

Computing "ALL" the trajectories would be quite a task and we'd all be here until doomsday working on it. Perhaps you want a range of trajectories. Then decide how coarse to make the steps between trajectories.

[eric]

Sorry....my english is not so good. I'm speaking about trajectories (path) and velocity All trajectories is in my dream, the focus will be to know the velocities area when the car stop to accelerate on a reference point until the car stop. Inside this aera, i would like to know the velocity of the car on a specific point

[Walter Roberson]

Please post an example diagram showing what you want

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

[eric]

Yes, it'll be better with a diagram. 1 - A reference path and speed on a road 2 - A point on the reference Path (to determinate a path vector) with a single speed 2 - A car with a mass, dimension and tire 3 - Many possible trajectories from the path vector based on the reference single speed. 2 options : The car in acceleration and the car stop to accelerate on the reference point. 4 - Determinate with mathlab the aera from the reference point based on a specific speed (i want to know from the reference point, where the car will be at 10 km/H, at 100 km etc..)

[Jan]

+1, I love your diagram. This is my question of the week.

Btw., the program is called "Matlab" from Matrix Laboratory, so there is no h in between.

Answer 1

[Jan]

This looks like a set of initial value problems. You can create a differential function, which considers friction, the parameters of the car, external forces etc and integrate it by e.g. ODE45 from the initial value. Then the control parameters are varied, e.g. the accelerating force of the engine.

But, there is a nearly infinite number of possible solutions as far as I understand. And the "nearly" comes only from the limited precision of floating point arithmetic in computers. This would mean, that you should create the model in form of a wave of matter like for quantum physical particles.

I think more discussions about your goal are required.