Simulink Object tracking

I'm presently working on UAV obstacle avoidance. In this stage of my work I have developed an obstacle avoidance algorithm and want to simulate it. However I don't want to get my hands dirty with aircraft dynamics for the time being. I want to assume a point that has a constant velocity and at vicinity of an obstacle exert a "velocity" command. This will result a new trajectory that will avoid the imaginary obstacle. Now the problem is that in Sim Mechanic bodies are not really treated as points (although you can define zero mass and zero inertia tensor). Furthermore, I cannot apply a "velocity" to a mass but only forces. I might be on the wrong track (using Sim Mechanics)and have to use a different Simulink toolbox. Maybe I just have to use Matlab.

Answer 1

[Guy Rouleau]

If you care only about the kinematics of 2 points in space, I agre that there is no need for SimMechanics and Simulink or MATLAB should be enough.

If you have system composed of multiple bodies, like a robot, you might want to use SimMechanics.

In SimMechanics, yo have 2 options:

- You can build a simple P(maybe PI) controller around your mass to control it in velocity. Since yo do not care about aerodynamics, it should be as simple as a sum and a gain block.

- You can specify the motion of your body through a joint. Use a Bushing if your motion is 6dof, or a any other joint for the dof you want to actuate (for example a custom joint with 3 translation if you do not care about rotation). Then you actuate this joint using a Joint Actuator set to motion.

One tip, do not feed discontinuous trajectories to the motion actuator, use a transfer function to smooth things as explained here:

http://www.mathworks.com/help/toolbox/physmod/mech/ug/f2-117031.html

[Shahab]

I am just modelling the whole thing in Matlab