55 citations · 90 across the 24 of their papers we have counts for
21 papers · 1 filter
Filtering for Liveness: Recurrence via Backup Reachability Control Barrier Functions
David E. J. van Wijk, Pio Ong, Aaron D. Ames +1
Liveness requires a dynamical system to repeatedly accomplish a desired objective over time. In this work, we consider a particular form of liveness known as recurrence, which requ…
Safety Filtering with an Infinite Number of Constraints
Max H. Cohen, Pio Ong, Pol Mestres +1
Control barrier functions (CBFs) provide a rigorous framework for designing controllers enforcing safety constraints. While CBF theory is well-developed for a finite number of safe…
SafeSpace: Aggregating Safe Sets from Backup Control Barrier Functions under Input Constraints
Pio Ong, David E. J. van Wijk, Massimiliano de Sa +2
Control barrier functions (CBFs) provide a principled framework for enforcing safety in control systems -- yet the certified safe operating region in practice is often conservative…
Steering with Contingencies: Combinatorial Stabilization and Reach-Avoid Filters
Yana Lishkova, Pio Ong, Sander Tonkens +2
In applications such as autonomous landing and navigation, it is often desirable to steer toward a target while retaining the ability to divert to at least (out of ) alterna…
Input-to-State Safe Backstepping: Robust Safety-Critical Control with Unmatched Uncertainties
Max H. Cohen, Pio Ong, Aaron D. Ames
Guaranteeing safety in the presence of unmatched disturbances -- uncertainties that cannot be directly canceled by the control input -- remains a key challenge in nonlinear control…
Explicit Control Barrier Function-based Safety Filters and their Resource-Aware Computation
Pol Mestres, Shima Sadat Mousavi, Pio Ong +4
This paper studies the efficient implementation of safety filters that are designed using control barrier functions (CBFs), which minimally modify a nominal controller to render it…
From Bundles to Backstepping: Geometric Control Barrier Functions for Safety-Critical Control on Manifolds
Massimiliano de Sa, Pio Ong, Aaron D. Ames
Control barrier functions (CBFs) have a well-established theory in Euclidean spaces, yet still lack general formulations and constructive synthesis tools for systems evolving on ma…
Combinatorial Control Barrier Functions: Nested Boolean and p-choose-r Compositions of Safety Constraints
Pio Ong, Haejoon Lee, Tamas G. Molnar +2
This paper investigates the problem of composing multiple control barrier functions (CBFs) -- and matrix control barrier functions (MCBFs) -- through logical and combinatorial oper…
Matrix Control Barrier Functions
Pio Ong, Yicheng Xu, Ryan M. Bena +2
This paper generalizes the control barrier function framework by replacing scalar-valued functions with matrix-valued ones. Specifically, we develop barrier conditions for safe set…
On the Properties of Optimal-Decay Control Barrier Functions
Pio Ong, Max H. Cohen, Tamas G. Molnar +1
Control barrier functions provide a powerful means for synthesizing safety filters that ensure safety framed as forward set invariance. Key to CBFs' effectiveness is the simple ine…
Secure Safety Filter Design for Sampled-data Nonlinear Systems under Sensor Spoofing Attacks
Xiao Tan, Pio Ong, Paulo Tabuada +1
This paper presents a secure safety filter design for nonlinear systems under sensor spoofing attacks. Existing approaches primarily focus on linear systems which limits their appl…
Computationally Efficient Safe Control of Linear Systems under Severe Sensor Attacks
Xiao Tan, Pio Ong, Paulo Tabuada +1
Cyber-physical systems are prone to sensor attacks that can compromise safety. A common approach to synthesizing controllers robust to sensor attacks is secure state reconstruction…
Rectified Control Barrier Functions for High-Order Safety Constraints
Pio Ong, Max H. Cohen, Tamas G. Molnar +1
This paper presents a novel approach for synthesizing control barrier functions (CBFs) from high relative degree safety constraints: Rectified CBFs (ReCBFs). We begin by discussing…
Hierarchical Event-Triggered Systems: Safe Learning of Quasi-Optimal Deadline Policies
Pio Ong, Manuel Mazo, Aaron D. Ames
We present a hierarchical architecture to improve the efficiency of event-triggered control (ETC) in reducing resource consumption. This paper considers event-triggered systems gen…
Safety of Linear Systems under Severe Sensor Attacks
Xiao Tan, Pio Ong, Paulo Tabuada +1
Cyber-physical systems can be subject to sensor attacks, e.g., sensor spoofing, leading to unsafe behaviors. This paper addresses this problem in the context of linear systems when…
Characterizing Smooth Safety Filters via the Implicit Function Theorem
Max H. Cohen, Pio Ong, Gilbert Bahati +1
Optimization-based safety filters, such as control barrier function (CBF) based quadratic programs (QPs), have demonstrated success in controlling autonomous systems to achieve com…
Intermittent Safety Filters for Event-Triggered Safety Maneuvers with Application to Satellite Orbit Transfers
Pio Ong, Aaron D. Ames
In balancing safety with the nominal control objectives, e.g., stabilization, it is desirable to reduce the time period when safety filters are in effect. Inspired by traditional s…
Sample-and-Hold Safety with Control Barrier Functions
Gilbert Bahati, Pio Ong, Aaron D. Ames
A common assumption on the deployment of safeguarding controllers on the digital platform is that high sampling frequency translates to a small violation of safety. This paper inve…
Stability and Safety through Event-Triggered Intermittent Control with Application to Spacecraft Orbit Stabilization
Pio Ong, Gilbert Bahati, Aaron D. Ames
In systems where the ability to actuate is a scarce resource, e.g., spacecrafts, it is desirable to only apply a given controller in an intermittent manner--with periods where the…
Safe Backstepping with Control Barrier Functions
Andrew J. Taylor, Pio Ong, Tamas G. Molnar +1
Complex control systems are often described in a layered fashion, represented as higher-order systems where the inputs appear after a chain of integrators. While Control Barrier Fu…
Safety-Critical Event Triggered Control via Input-to-State Safe Barrier Functions
Andrew J. Taylor, Pio Ong, Jorge Cortes +1
The efficient utilization of available resources while simultaneously achieving control objectives is a primary motivation in the event-triggered control paradigm. In many modern c…