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Unread 12-19-2012, 12:44 PM
winchymatt winchymatt is offline
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Re: Motion Profiling

Quote:
Originally Posted by AustinSchuh View Post
Good point Jared. Once you have a profile, you need to follow it.

My favorite controller for following trajectories is as follows (I think this is a modification of 3). I used it before I got tired of hand-tuning the PD for the drivetrain and switched to state feedback.

pwm = P * error + D * ((error - prev_error) / dt - goal_velocity) + Kv * goal_velocity + Ka * goal_acceleration
Hi,

Realise this is an old thread, but hopefully you will pick this up..

I have been working with PID controllers for a while now, but have never looked at adding feed forward terms. This looks really interesting for a hydraulic system I'm currently working on.

I have a few questions with regards to your controller above:

1) What is your (dt) term within the D part of your controller.

2) Do you determine the goal_velocity and goal_acceleration from the goal position within the controller, or do you send these in from your trajectroy planner?

3) Can you point me to a code example of this controller?

I have a bunch of other questions but figured I would start with this..

Matt.