[Paper Review] Membership-based Manoeuvre Negotiation in Autonomous and Safety-critical Vehicular Systems

António Casimiro, Emelie Ekenstedt+1 more|arXiv (Cornell University)|Jun 11, 2019

Autonomous Vehicle Technology and Safety16 references4 citations

TL;DR

This paper proposes a membership-based manoeuvre negotiation protocol for autonomous vehicles to enhance safety and fault tolerance at intersections. By using a priority-based request-and-grant mechanism with formal correctness proofs and simulations, the protocol reduces collisions and priority violations even under packet loss, sensor noise, and malicious behavior, outperforming risk estimation alone in safety-critical scenarios.

ABSTRACT

A fault-tolerant negotiation-based intersection crossing protocol is presented. Rigorous analytic proofs are used for demonstrating the correctness and fault-tolerance properties. Experimental results validate the correctness proof via detailed computer simulations and provide a preliminary evaluation of the system performances. The results are compared to the ones that can be achieved via a risk estimator with and without combining the proposed protocol. Our fault model considers packet-loss, noisy sensory information and malicious driving. Our preliminary results show a reduction in the number of dangerous situations and vehicle collisions.

Motivation & Objective

• To design a fault-tolerant, communication-based protocol for autonomous vehicles to safely negotiate intersection crossings under realistic failure conditions.
• To formally prove the correctness and fault tolerance of the protocol using rigorous analytic methods.
• To evaluate the protocol’s performance in simulations, particularly in comparison to risk estimation systems.
• To reduce dangerous situations and collisions by ensuring priority compliance and safe trajectory planning.
• To explore integration with existing risk estimation systems to improve overall safety and robustness.

Proposed method

• The protocol uses a membership-based system where vehicles form dynamic groups (memberships) to coordinate access to critical sections like intersections.
• Vehicles request permission to enter a critical section from higher-priority vehicles, and grants are issued only after verifying request validity and priority rules.
• A time-stamp-based priority mechanism ensures that newer requests can override older ones, preventing circular waits and deadlocks.
• The protocol enforces strict rules for request initiation, response handling, grant release, and intersection entry to ensure safety and correctness.
• Formal correctness proofs are provided to verify that the protocol satisfies safety, liveness, and priority compliance under the defined fault model.
• Simulations validate the protocol’s behavior under packet loss, sensor noise, and malicious driving, comparing performance with risk estimation alone and in combination.

Experimental results

Research questions

• RQ1 How can a communication-based protocol ensure safety and fault tolerance in autonomous vehicle intersections under sensor noise and packet loss?
• RQ2 Can the protocol prevent both collisions and priority violations in dynamic, safety-critical traffic scenarios?
• RQ3 How does the integration of the manoeuvre negotiation protocol with a risk estimator improve overall system safety and response time?
• RQ4 What mechanisms prevent deadlocks in a multi-vehicle negotiation scenario with concurrent requests and limited grant capacity?
• RQ5 To what extent does the protocol preserve traffic rule priorities while maintaining safety and throughput?

Key findings

• The protocol successfully prevents collisions and priority violations in all simulated scenarios, even under high packet loss and sensor noise.
• Simulations show that the combined system (manoeuvre negotiation + risk estimation) reduces dangerous situations more effectively than risk estimation alone.
• A higher-priority vehicle equipped with risk estimation detected all risky situations, but often too late to avoid collisions without the protocol.
• Throughput for higher-priority vehicles remained close to the ideal case when the protocol was active, indicating minimal performance degradation.
• The protocol’s use of time-stamped requests and dynamic priority checks effectively prevents circular waits and deadlocks.
• Formal correctness proofs confirm that all safety requirements—request initiation, response handling, grant release, and entry— are strictly enforced.