# Jam Mitigation for Autonomous Convoys via Behavior-Based Robotics
###### Abstract
There have been some limited efforts focused more narrowly on the topic of jamming as it relates to convoys, with a greater body of work focused on investigating the effects of jamming on vehicular ad-hoc networks (VANET) in general [11; 12; 13]. On the topic of jamming and its effects of vehicular convoys, there has been some work in developing a framework to measure the impact of the attack and a convoy's resilience. [PERSON] et al. examined three Cooperative Adaptive Cruise Control convoy controllers and how various attacks such as jamming and data injection impacted their respective performance [7]. Both an attacker model and an evaluation framework were developed for a thorough examination of what sort of attack detection and attack resilience algorithms should be used to resist the effects of attacks on the VANETs. In another convoy specific effort, [PERSON] et al. investigated how stealthy jamming attacks impacted convoy stability [14]. The stealthy jammer performed jamming against a simulated convoy's basic safety message (BSM), which contains information such as vehicle speed, position, and acceleration, over the control channel of dedicated short-range communications (DSRC), but only when the probability of being detected was low. The probability of being detected was determined based on how significantly jamming at a particular time would affect the packet loss ratio of the communications. To detect the stealthy jams, they analyzed received power and transmission delays of messages to differentiate between jamming attacks and normal interference. The effects of jamming on VANETs in general is a more thoroughly explored topic. Various efforts have focused on how jamming affects the transmission of BSMs over DSRC in relation to Forward Collision Warning capabilities [11; 12; 13]. These efforts create attack models to quantify the effects of the jamming attacks and come up with different mechanisms to mitigate their effects. [PERSON] et al. looked at vehicle distance with packet delivery ratio to detect jams, causing the system to enter a fail-safe mode [11]. [PERSON] et al. utilized redundant channels and data through dissimilar message types to reduce the effectiveness of jams [12]. In a different effort, [PERSON] et al. looked to develop architectures resistant to jamming by using dual and triple-redundant channels at higher power ratings to enable BSM transmission [13]. Other efforts have leveraged more of the Wireless Access in Vehicular Environment standards in trying to detect jams, such as [PERSON]'s work in looking at beacon frequency from roadside units to detect jams and broadcast warnings to other network members in its vicinity [8]. As a whole, prior efforts related to jamming of convoys and VANETS have had a heavy focus on detection, with a response of either broadcasting warnings to convoy vehicles or entering fail-safe modes. Rather than investigating the issue of jam detection, which has been the focus of the previous literature, our proposed solution instead focuses on control-oriented countermeasures when jamming is unavoidable. We aim to develop methods and techniques to allow for continued convoy operation in the face of these denial-of-service attacks, mitigating the undesired outcome of jamming attacks, rather than the jamming itself. There are a variety of control approaches and architectures utilized in multirobot autonomous convoying. More broadly speaking, multirobot convoying is a subset of formation control, and the proper choice for formation control design is dependent on which factors need to be prioritized, such as formation shape generation time [15], formation robustness during network congestion [16], and flexible prioritization between system performance and control effort [17]. One particularly robust formation control approach for dynamic environments is behavior-based robotics. In behavior-based robotics, robotic control is built as a collection of basic behaviors.