84 citations · 464 across the 36 of their papers we have counts for
8 papers · 1 filter
Combining DVL-INS and Laser-Based Loop Closures in a Batch Estimation Framework for Underwater Positioning
Amro Al-Baali, Thomas Hitchcox, James Richard Forbes
Correcting gradual position drift is a challenge in long-term subsea navigation. Though highly accurate, modern inertial navigation system (INS) estimates will drift over time due…
Synthesizing Control Laws from Data using Sum-of-Squares Optimization
Jason J. Bramburger, Steven Dahdah, James Richard Forbes
The control Lyapunov function (CLF) approach to nonlinear control design is well established. Moreover, when the plant is control affine and polynomial, sum-of-squares (SOS) optimi…
Cascaded Model Predictive Control of a Tandem-Rotor Helicopter
Faraaz Ahmed, Ludwik Sobiesiak, James Richard Forbes
This letter considers cascaded model predictive control (MPC) as a computationally lightweight method for controlling a tandem-rotor helicopter. A traditional single MPC structure…
An Adaptive Graduated Nonconvexity Loss Function for Robust Nonlinear Least Squares Solutions
Kyungmin Jung, Thomas Hitchcox, James Richard Forbes
Many problems in robotics, such as estimating the state from noisy sensor data or aligning two point clouds, can be posed and solved as least-squares problems. Unfortunately, vanil…
Decentralized State Estimation: An Approach using Pseudomeasurements and Preintegration
Charles Champagne Cossette, Mohammed Ayman Shalaby, David Saussié +1
This paper addresses the problem of decentralized, collaborative state estimation in robotic teams. In particular, this paper considers problems where individual robots estimate si…
Multi-Robot Relative Pose Estimation and IMU Preintegration Using Passive UWB Transceivers
Mohammed Ayman Shalaby, Charles Champagne Cossette, Jerome Le Ny +1
Ultra-wideband (UWB) systems are becoming increasingly popular as a means of inter-robot ranging and communication. A major constraint associated with UWB is that only one pair of…
Closed-Loop Koopman Operator Approximation
Steven Dahdah, James Richard Forbes
This paper proposes a method to identify a Koopman model of a feedback-controlled system given a known controller. The Koopman operator allows a nonlinear system to be rewritten as…
Improving Self-Consistency in Underwater Mapping Through Laser-Based Loop Closure (Extended)
Thomas Hitchcox, James Richard Forbes
Accurate, self-consistent bathymetric maps are needed to monitor changes in subsea environments and infrastructure. These maps are increasingly collected by underwater vehicles, an…