11 papers
Global Exponential Stabilization of a 3D Nonholonomic Vehicle in Spherical Coordinates
Kwang Hak Kim, Velimir Todorovski, Miroslav Krstic
Many spatial (3D) vehicles, including AUVs and fixed-wing aircraft, are effectively nonholonomic and subject to limited actuation, such that continuous time-invariant stabilization…
Global Exponential Stabilization of the Kinematic Bicycle Model of a Car in Polar Coordinates
Velimir Todorovski, Kwang Hak Kim, Alessandro Astolfi +1
At parking speeds, the kinematic bicycle is the prevailing model for car-like vehicles. Yet, despite its wide use, stabilizing feedback laws for this system are scarce in the liter…
Nonholonomic Robot Parking by Feedback -- Part II: Nonmodular, Inverse Optimal, Adaptive, Prescribed/Fixed-Time and Safe Designs
Kwang Hak Kim, Velimir Todorovski, Miroslav Krstić
For the unicycle system, we provide constructive methods for the design of feedback laws that have one or more of the following properties: being nonmodular and globally exponentia…
Nonholonomic Robot Parking by Feedback -- Part I: Modular Strict CLF Designs
Velimir Todorovski, Kwang Hak Kim, Alessandro Astolfi +1
It has been known in the robotics literature since about 1995 that, in polar coordinates, the nonholonomic unicycle is asymptotically stabilizable by smooth feedback, even globally…
Integrator Forwading Design for Unicycles with Constant and Actuated Velocity in Polar Coordinates
Miroslav Krstic, Velimir Todorovski, Kwang Hak Kim +1
In a companion paper, we present a modular framework for unicycle stabilization in polar coordinates that provides smooth steering laws through backstepping. Surprisingly, the same…
Modular Design of Strict Control Lyapunov Functions for Global Stabilization of the Unicycle in Polar Coordinates
Velimir Todorovski, Kwang Hak Kim, Miroslav Krstic
Since the mid-1990s, it has been known that, unlike in Cartesian form where Brockett's condition rules out static feedback stabilization, the unicycle is globally asymptotically st…
Half-Global Deadbeat Parking for Dubins Vehicle
Miroslav Krstić, Kwang Hak Kim, Velimir Todorovski
This paper presents a framework for stabilizing the Dubins vehicle model to zero in finite time (deadbeat parking) by interpreting distance as a time-like variable. We develop cont…
Inverse Optimal Feedback and Gain Margins for Unicycle Stabilization
Kwang Hak Kim, Velimir Todorovski, Miroslav Krstić
The recent development of globally strict control Lyapunov functions (CLFs) for the challenging unicycle parking problem provides a foundation for pursuing optimality. We address t…
Learning-based Prescribed-Time Safety for Control of Unknown Systems with Control Barrier Functions
Tzu-Yuan Huang, Sihua Zhang, Xiaobing Dai +4
In many control system applications, state constraint satisfaction needs to be guaranteed within a prescribed time. While this issue has been partially addressed for systems with k…
Newton Nonholonomic Source Seeking for Distance-Dependent Maps
Velimir Todorovski, Miroslav Krstic
The topics of source seeking and Newton-based extremum seeking have flourished, independently, but never combined. We present the first Newton-based source seeking algorithm. The a…
Practical Prescribed-Time Seeking of a Repulsive Source by Unicycle Angular Velocity Tuning
Velimir Todorovski, Miroslav Krstic
All the existing source-seeking algorithms for unicycle models in GPS-denied settings guarantee at best an exponential rate of convergence over an infinite interval. Using the rece…