Why would one want a multi-agent system unstable

Abstract:  In everyday driving, many traffic maneuvers such as merges, lane changes, passing through an intersection, require negotiation between independent actors/agents. The same is true for mobile robots autonomously operating in a space open to other agents (e.g., humans, robots, etc.). Negotiation is an inherently difficult concept to code into a software algorithm. It has been observed in computer simulations that some “decentralized” algorithms produce gridlocks while others never do. It has turned out that gridlocking algorithms create locally stable equilibria in the joint inter-agent space, while, for those that don’t gridlock, equilibria are unstable – hence the title of the talk.

We use Control Barrier Function (CBF) based methods to provide collision avoidance guarantees. The main advantage of CBFs is that they result in relatively easier to solve convex programs even for nonlinear system dynamics and inherently non-convex obstacle avoidance problems. Six different CBF-based control policies were compared for collision avoidance and liveness (fluidity of motion, absence of gridlocks) on a 5-agent, holonomic-robot system. The outcome was then correlated with stability analysis on a simpler, yet representative problem. The results are illustrated by extensive simulations and a vehicle experiment with stationary obstacles.

Bio: Mrdjan Jankovic received undergraduate EE degree from Belgrade University and MS and DSc degrees from Washington University, St. Louis. He held postdoctoral positions with Washington University and UC Santa Barbara, before joining Ford in 1995. He is currently a Senior Technical Leader at Ford Research, working on development of control technologies for powertrain and driver assist applications. Dr. Jankovic coauthored some 140 technical publications and is a co-inventor of over 90 US patents, with 24 used in Ford products sold worldwide. For his contribution to automotive control technology he has received awards from IFAC, AACC, IEEE, SAE, as well as Ford. Dr. Jankovic is a Fellow of the IEEE and a member of the US National Academy of Engineering.

***Event will take place in hybrid format. The location for in-person attendance will be room 1311 EECS.   Attendance will also be possible via Zoom. Zoom link and password will be distributed to the Controls Group e-mail list-serv.

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This seminar will be recorded and posted to the Control Seminar website