# Projects

The following is a list of projects I have worked on over the course of my graduate studies at Penn.

## Modeling and Compensation for First-Order Drag Effects on Quadrotors

This project was an attempt to 1) develop a simple lumped-parameter dynamic model for drag effects in the horizontal and vertical directions and 2) develop a controller to compensate for these effects. This resulted in a paper that was accepted to IEEE International Conference on Unmanned Aircraft Systems (ICUAS) in 2017.

## Inertial State Estimation for Quadrotors

This project was an extension of the previous one. Now that such a model has been developed, we wished to use this model to estimate the orientation and velocity of a quadrotor UAV using only the IMU. It turns out that the tilt component of attitude can be estimated, as well as the body-frame linear velocity and the yaw can be dead-reckoned, although it will drift. The tilt and the velocity are all that is needed to stabilize the quadrotor, and may be estimated if the yaw is unknown. In addition, our method makes it possible to estimate the thrust coefficient and first-order drag coefficients of the quadrotor's dynamic model.

## Vision-Aided Inertial State Estimation For Quadrotors

We can add a camera to the robot and use feature-based methods to improve the yaw estimates. The tilt and velocity estimates from the filter can be used to reject outlying feature correspondences in a computationally efficient way.