About

Gender

Male


Location

West Lafayette, Indiana


About Me:

I'm a Visiting Assistant Professor in Aerospace engineering at Purdue University. I'm working on unmanned aerial/ ground vehicle navigation in environments without GPS.


Please tell us a bit about your UAV interest

http://hsl.dynalias.com/hsl/index.php?page=unmanned-vehicles


Hometown:

Lake Lotawana, Missouri


Activity Feed

James Goppert replied to K V's discussion Pitch Oscillations during Forward Descent flight in Auto
"Hey Kautilya!

If you are descending quickly, you might be running into https://en.wikipedia.org/wiki/Vortex_ring_state, where you are flying into your own downwash. So you could try lowering your maximum descent rate."
Oct 24, 2015
James Goppert left a comment for James Goppert
"The problem with the other fixedwing autopilot is probably that I don't have the airspeed hooked up correctly as you suggest. The backside autopilot is using ground speed. It is probably a unit error and if you can spot it feel free to submit a pull…"
Nov 15, 2013
James Goppert left a comment for James Goppert
"We actually just fixed HIL for the backside fixedwing autopilot last night, this will probably help: https://github.com/PX4/Firmware/pull/530"
Nov 15, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"most stable : apm 2.6
most powerful: pix hawk/ px4 (these are basically the same, think of the pix hawk as px4 2.0)
vrbrain: I don't have much experience with."
Nov 6, 2013
James Goppert commented on James Goppert's blog post PX4 Segway Robot
"Jason, if you were referring to not numerically taking the derivative of the pitch signal, I'm not. I'm using the pitch rate from the gyros for the D term. I am not using the encoder wheel speed, but I get the same effect."
Nov 4, 2013
James Goppert commented on James Goppert's blog post PX4 Segway Robot
"Hey thanks Jason! I have a full simulation in scilab with PIDs working for position control but agree that it is difficult especially with a short robot. I started with a  robot about the same size as the arduroller…"
Nov 4, 2013
James Goppert commented on James Goppert's blog post PX4 Segway Robot
"The current source code is here if anyone is interested. Hopefully it will be merged with PX4 master soon.
https://github.com/jgoppert/Firmware/tree/roboclaw
We are going to use this as part of an undergraduate aero/astro engr. controls lab at…"
Nov 4, 2013
James Goppert posted a blog post
My roboclaw/pololu based segway is working well now with the new motors. I have closed the attitude loop with the gyros and the EKF pitch estimate. I will soon close the position loop with the encoders.
Nov 3, 2013
James Goppert commented on PX4's blog post PX4 Platform Update
"It is an awesome feeling seeing software that I contributed to and helped develop so recently flying an aircraft on the other side of the world! I am really looking forward to getting some time for my own test flights. Thanks again guys for creating…"
Jan 24, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"That is some impressive flying/ attitude estimation :-). I agree it is amazing all that they manged to do with the 8-bit processor.

On the PX4 right now we are playing around with some of the suggestions on this post and doing some other work to…"
Jan 23, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"I just heard from the guys at ETHZ that the first flight of this EKF went well for the fixed wing! Our control gains still need some tuning though.
 @Dan Thanks for the input. Really respect the work you guys do at ACFR. I can see how a simultaneous…"
Jan 23, 2013
James Goppert left a comment for William Premerlani
"Hey Bill. I really appreciate you taking the time to look at the EKF stuff! If we get into a heated debate about a bunch of math I think that is a good thing and I don't take it personally. That is what engineers are supposed to do. :-). I think I…"
Jan 22, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"Here is why I think the EKF is doing something similar to your algorithm but in a more robust way. Granted your way is a good way to do it without a combined position/velocity/attitude EKF.If we start with the EKF navigation velocity propagation:V1…"
Jan 22, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"I think it is equivalent to the time integral, but will have to look at it more closely. Good point on the latency :-). I should add that to my sensor hardware-in-the-loop model as well."
Jan 22, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"@Bill: I think I have wrapped my head around your equations. From what I can tell you are using the GPS velocity measurements to correct the attitude. This correction happens naturally in the combined position/attitude EKF. When GPS velocity…"
Jan 22, 2013
James Goppert commented on James Goppert's blog post PX4 Autopilot: New Software! Hardware Accelerated Extended Kalman Filter/ Sensor Level HIL/ OO Control Library
"OK, yeah makes sense how a quad moving forward spinning on it's axis would totally mess up the centrip accel prediction. Thanks again for the resources. I don't have time to tackle this right now, but will get into it soon."
Jan 22, 2013
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