Departmental Papers (CIS)

Date of this Version

2-2016

Document Type

Journal Article

Comments

ACM Transactions on Embedded Computing Systems, Volume 15 Issue 1, February 2016

Abstract

This paper focuses on the design of safe and attack-resilient Cyber-Physical Systems (CPS) equipped with multiple sensors measuring the same physical variable. A malicious attacker may be able to disrupt system performance through compromising a subset of these sensors. Consequently, we develop a precise and resilient sensor fusion algorithm that combines the data received from all sensors by taking into account their specified precisions. In particular, we note that in the presence of a shared bus, in which messages are broadcast to all nodes in the network, the attacker’s impact depends on what sensors he has seen before sending the corrupted measurements. Therefore, we explore the effects of communication schedules on the performance of sensor fusion and provide theoretical and experimental results advocating for the use of the Ascending schedule, which orders sensor transmissions according to their precision starting from the most precise. In addition, to improve the accuracy of the sensor fusion algorithm, we consider the dynamics of the system in order to incorporate past measurements at the current time. Possible ways of mapping sensor measurement history are investigated in the paper and are compared in terms of the confidence in the final output of the sensor fusion. We show that the precision of the algorithm using history is never worse than the no-history one, while the benefits may be significant. Furthermore, we utilize the complementary properties of the two methods and show that their combination results in a more precise and resilient algorithm. Finally, we validate our approach in simulation and experiments on a real unmanned ground robot.

Subject Area

CPS Embedded Control

Publication Source

ACM Transactions on Embedded Computing Systems

Volume

15

Issue

1

Start Page

Article No. 21

DOI

10.1145/2847418

Keywords

Special-purpose and Application-based Systems, Process control systems, Real-time and embedded systems, Security and Protection, Unauthorized access, Cyber-Physical Systems security, sensor fusion, fault-tolerance, fault-tolerant algorithms

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Date Posted: 26 January 2016

This document has been peer reviewed.