  The safety-critical nature of vehicle steering is one of the main motivations
for exploring the space of possible cyber-physical attacks against the steering
systems of modern vehicles. This paper investigates the adversarial
capabilities for destabilizing the interaction dynamics between human drivers
and vehicle haptic shared control (HSC) steering systems. In contrast to the
conventional robotics literature, where the main objective is to render the
human-automation interaction dynamics stable by ensuring passivity, this paper
takes the exact opposite route. In particular, to investigate the damaging
capabilities of a successful cyber-physical attack, this paper demonstrates
that an attacker who targets the HSC steering system can destabilize the
interaction dynamics between the human driver and the vehicle HSC steering
system through synthesis of time-varying impedance profiles. Specifically, it
is shown that the adversary can utilize a properly designed non-passive and
time-varying adversarial impedance target dynamics, which are fed with a linear
combination of the human driver and the steering column torques. Using these
target dynamics, it is possible for the adversary to generate in real-time a
reference angular command for the driver input device and the directional
control steering assembly of the vehicle. Furthermore, it is shown that the
adversary can make the steering wheel and the vehicle steering column angular
positions to follow the reference command generated by the time-varying
impedance target dynamics using proper adaptive control strategies. Numerical
simulations demonstrate the effectiveness of such time-varying impedance
attacks, which result in a non-passive and inherently unstable interaction
between the driver and the HSC steering system.

Systems and Control;Robotics;Systems and Control