control: nonlinear and hybrid system control,
Hamiltonian approach, open-loop control of stochastic dynamical
systems, use of stochastic processes for computing control
GPS-free navigation: The navigation
of aerial and ground ve- hicles based on the GPS
a major challenge for the general use of autonomous vehicles. The
of the GPS signal can lead to catastrophic outcomes. We work on a feedback
control design that allows a Dubins vehicle, which is a mathematicl
limited turning rate vehicles and mobile robots, to enter a circular trajectory
using only range based measurements from the vehicle to the center of
the trajectory. Our work is based on a novel state space kinematic
model with the state that is composed of two continuous and one
discrete state variables. The evolution of the discrete state variable
is not completely defined by the model and the control design has to
deal with the ambiguity of this variable.
Navigation with the
avoidance of unsafe configurations: Long-time
planning horizons are required to safely navigate one vehicle in the
presence of another, possibly non-cooperative vehicle. They give rise
to computational issues preventing the real-time implementation of
algorithms. We test our
numerical simulations and small-scale robot
experiments. The image on the right shows snapshots of an experiment in
two robots safely navigate around each other until one of them
succeeds to enter safely a circular sector behind the other
This sort of
experiments help us advance the field of autonomous navigation.
the core of the promise of using microrobots for diagnostics,
surgery, drug delivery and other potential medical applications is
the design of microrobots that can be manipulated in physiological
environments. Our work has been focused on modeling and controlling a
10um swimming robot, the so-called achirial microswimmer, composed of
firmly connected magnetic beads which can be propelled through a fluid
environment by a roational magnetic field.
|Control of a mini segway
(MinSeg) device: This device is composed of an NXT Lego
driving the wheels and an Arduino board with a shield that has a solid
state gyro. The motor encoder measures wheel rotations while the gyro
measures the turning rate of the board.
We derived dynamic systems equations, performed numerical
simulations, and designed a digital control that
achieves balancing the two-wheel mechanism. We continue to use the
device as an
experimental platform for advanced control concepts.
|Miniature quadrotors are
attractive systems for experiments with an advanced control
Our work is focused on a feedback, off-board control of quadrotors that
fly with an off-the-shelf on-board controller. The presence of the
on-board controller completely changes the original quadrotor dynamics,
requires the off-board control to be robust,or adaptive to changes.
stochastic control: The illustrative movie
on the right (link) shows five differential
drive robots navigating into
a formation. The unique property of the implemented control algorithm
that it anticipates the uncertainity of teammate navigation. We
the Kalman smoother for computing the control based on a
path-integral approach. The early version of this work received the
best student paper award at the DARS 2012 symposium.
stochastic control: We
use stochastic processes to model any lack of data resulting in a
dynamic uncertainty, for example, an unknown target trajectory, or even
a disappearing target. These
stochastic models are integrated in a feedback control that anticipates
the uncertainty. Follow the (link) for an animation illustrating
our work on a Dubins
feedback control for stochastic target tracking. The same controller
robustly follows the target that goes along a straight line (link),
or complex path (link). For a control under
the presence of a stochastic wind, follow the (link).
surface traffic management: This
research has been performed in collaboration with NASA Ames and its
SARDA (Spot and Runway Departure Advisor) team. We investigated the
integration of ramp-area aircraft trajectories and their timing into
the optimization of airport taxiway and runway operations. Our analysis
included Dallas/Fort Worth (DFW) and Charlotte Douglas (CLT)
International Airports. Since data for aircraft ramp area trajectories
are typically unavailable, we used an inexpensive, scaled-down robot
experiment to collect some critical data about aircraft trajectories.
Our robot experiment was featured in the Airspace Systems Program
Newsletter, Apr-Jun, 2014. (video)
the relation between manipulator design, workspace and performance is
important not only for a robot manipulator executing a complex task,
but also for wearable robots closely interacting with human body
movements, which can be used in stroke rehabilitation. So far we have
healthy human arm movements, grasping and joint coordination in
reach-to-grasp movements. We also proposed novel methods for measuring
the dissimilarity of movements based on mapping the complexity between
arm trajectories and a low-dimensional dissimilarity analysis. This
research contributes with a quantitative analysis of high-resolution
trajectory data for the purpose of diagnostics, as well as therapy
Lab members (alphabetical
Jay Ryan Roldan,
Marco Carmona, PhD
Andrew Wong, MS
Margaret Clinton, MS (co-advised with Prof. Wehner)
Won Ko, MS
Former lab members:
Boivin, 2021, PhD thesis (co-advised with Prof. Wehner), "Study of Kinesthetic Feedback Control for
Compliant Proprioceptive Touch for Soft Robotic Finger-Like Actuators"
William Jeremy Coupe, 2017, PhD thesis, "Optimization of Ramp Area Aircraft Push Back Time Windows in
the Presence of Uncertainty", Aerospace Engineer, NASA Ames
PhD thesis, "The Synergy of Human
Arm and Robotic System",
now Assistant Professor, Mechanical Engineering Department, Worcester Polytechnic Institute
Anderson, 2014, PhD thesis, "Uncertainty-Anticipating
Stochastic Optimal Feedback Control of Autonomous
Vehicle Models", Senior Software Engineer, Waymo
Leo Chen, 2019 MS, "Navigation of the Cozmo Robot using Computer Vision"
Joseph Grant, 2018, MS, "2-D Lidar Slam with V-REP Simulated Robot"
Alex Aranburu, 2018, MS thesis, "IMU Data Proceessing to Reconize Activities of Daily Living with Smart Headset"
Thompson, 2017, MS, "A Study of Reinforcement Learning Improvement
of Dubins Vehicle Circumnavigation Based Upon Range Measurements"
Circumnavigation Controller: UAV Circumnavigation
Study and Simulation"
Ryan Roldan, 2016, MS thesis, "Robotic Rehabilitation
Gaming Strategies and Low-Dimensional
Analysis of Hand
2013, MS thesis, "Robot Experiment
Analysis of Airport Ramp Area Time
Constraints and Generation of Optimal
Georgi Dinolov, AMS graduate student (first-year advisee)
Chien-Pin Chen, CE graduate student (visiting student)
Iris Huang, visiting graduate student
Murray, CE graduate student (visiting student)
AMS graduate student (first-year advisee)
Zachary Lamb, 2021, B.S. thesis, "Multi-Phase Non-Linear/LQR Control Design for a 2D Reusable Launch Vehicle"
Rory Grant, 2019, B.S. thesis, "Soft Robotic Finger Simulation Control"
Minghan Zhu, 2019, B.S. thesis, "Robot Following Control"
Jacob Stelzriede, 2018, B.S. thesis, "Navigation with Cozmo Modeled as a Two Wheeled Robot"
Smith, 2017, B.S. thesis, "Development of a Variable Output Maximum Power Point
Tracking Controller for Photovoltaic Systems"
Javier Ruiz, 2017, B.S. thesis, "Control and Estimation of a Self-Balancing MinSeg Robot"
Munishkin, 2016, B.S. thesis, "Control of a 'Desktop' Quadrotor"
Travis Rogers, visiting student
Anne Maun, 2015, B.S. thesis, "Quantifying the Progress of Learning of
Patients Performing in a Circle-Tracing
Carey-de la Torre, 2015, B.S. thesis, "Modeling and Control of
a MinSeg-like Robot"
Palmer, junior researcher