Youngmi Baek

A Hybrid V2X System for Safety-Critical Applications in VANET

Vehicular Ad-hoc Networks (VANETs) using a connected-car technology can support safety-critical applications in Cooperative Intelligent Transportation Systems (C-ITS). While WAVE/DSRC has been investigated by a number of researchers to support VANETs, it may not be easy to distribute WAVE/DSRC in the near future due to several practical obstacles. In this paper, we discuss an alternative to support V2X communication without using WAVE/DSRC. Therefore, we propose a novel hybrid system which incorporates a flexible mix of a cellular network and Wi-Fi Direct. Especially, to offload cellular traffic and alleviate additional cost, Wi-Fi Direct is used as a subsidiary method to enable communication by using local links without the help of infrastructure. Our proposed system provides 1) seamless connectivity and monitoring vehicles through a cellular network, 2) local data transmission through Wi-Fi Direct, and 3) solutions for reducing long connection establishment time of Wi-Fi Direct. The performance of the proposed system is evaluated in terms of the total discovery time and data usage in several scenarios in a real driving environment. Our preliminary results show a possibility of a smart mobile device-based approach for V2X communication.

Adaptive Transient Fault Model for Sensor Attack Detection

This paper considers the problem of sensor attack detection for multiple operating mode systems, building upon an existing attack detection method that uses a transient fault model with fixed parameters. For a multiple operating mode system, the existing method would have to use the most conservative model parameters to preserve the soundness in attack detection, thus not being effective in attack detection for some operating modes. To address this problem, we propose an adaptive transient fault model to use the appropriate parameter values in accordance with the change of the operating mode of the system. The benefit of our proposed system is demonstrated using real measurement data obtained from an unmanned ground vehicle.

Fundamental Topology-Based Routing Protocols for Autonomous Vehicles

It does not seem easy to generate reliable routes in Vehicular Ad-hoc Networks (VANETs) because of frequent link failures caused by vehicles mobility. In this regard, we analyze the characteristics of topology-based routing protocols in order to assess the feasibility of each protocol for vehicular environments. We plan to design an efficient routing protocol for VANETs in order to generate reliable and stable routes.

An Attack-Resilient Source Authentication Protocol in Controller Area Network

While vehicle to everything (V2X) communication enables safety-critical automotive control systems to better support various connected services to improve safety and convenience of drivers, they also allow automotive attack surfaces to increase dynamically in modern vehicles. Many researchers as well as hackers have already demonstrated that they can take remote control of the targeted car by exploiting the vulnerabilities of in-vehicle networks such as Controller Area Networks (CANs). For assuring CAN security, we focus on how to authenticate electronic control units (ECUs) in real-time by addressing the security challenges of in-vehicle networks. In this paper, we propose a novel and lightweight authentication protocol with an attack-resilient tree algorithm, which is based on one-way hash chain. The protocol can be easily deployed in CAN by performing a firmware update of ECU. We have shown analytically that the protocol achieves a high level of security. In addition, the performance of the proposed protocol is validated on CANoe simulator for virtual ECUs and Freescale S12XF used in real vehicles. The results show that our protocol is more efficient than other authentication protocol in terms of authentication time, response time, and service delay.

Performance Analysis of Sensor Fusion Models for Brake Pedal in a Brake-by-Wire System

This paper focuses on analyzing the performance of sensor fusion models for a brake pedal in electromechanical braking (EMB) systems. To properly control a brake, a signal obtained from a pedal is important and must be stable. Sensor fusion models can be used to make the pedal signal more stable and resilient against the abnormalities. In this work, a pedal sensor and a pedal effort sensor are exploited for the sensor fusion to control the brake. Then, we analyze the performance of each fusion model (e.g., average method, moving average method, median filter, iterative filter, and Marzullos algorithm) in various fault scenarios. We propose the hybrid method using multiple models to have the better resiliency and to detect the faulty sensor as well. For the practical experiments, we employ the real measurement data set obtained from a vehicle at different speeds. Then, its fused result is validated using EMB system test bench to confirm how the fused result influences on the motor of the brake.

Load-aware association with AP for internet-connected vehicles

For connected vehicles, vehicle ad-hoc network is capable to support various communication-based applications. Specially, WLAN-based vehicular Internet access can be a complementary and cost-effective solution considering the cost of cellular service. For WLAN-based Internet connected vehicles, we propose an efficient load-aware association mechanism which allocates vehicles to roadside APs properly, and eliminates the unnecessary steps during scanning phase. We defined the load condition as a set of parameters, relative priority of parameters, and determined decision weights in order to select one AP for each vehicle. We evaluated the performance of the proposed mechanism, comparing with the strongest-RSSI-first selection for AP. Depending on the traffic volume, the proposed mechanism showed better performance in the average throughput ratio by about 20%.

Graph Coloring for Smartphone-Based V2X System

To support safety critical application at low cost, we have proposed the smartphone-based V2X system as an alternative of DSRC. To assess the feasibility of our system on the road, we should address channel interference. We briefly describe (1) our smartphone-based system, (2) a typical graph coloring algorithm TABUCOL, and (3) our idea to avoid interference.

Performance Analysis of Sensor Fusion Models Using Unmanned Ground Vehicle

In this paper, we analyze the performance of various sensor fusion models using an unmanned ground vehicle. In the given attack scenarios, we examine how the attacks influence on each fusion model by comparing the results of the models. We conduct the experiments with real measurement data obtained from an unmanned ground vehicle.

Lightweight Authentication Method for Controller Area Network

In the age of smart and connected vehicles, there are significant issues in providing security for in-vehicle networking. Many security efforts for in-vehicle networks are still insufficient to build a lightweight security mechanism. Typically, it comes from the limitations of Controller Area Network (CAN) protocol common to in-vehicle network. We propose a lightweight authentication method based on one-way hash chain in CAN. In addition, we identify three technical challenges to be addressed for the proposed method and present our key idea to address them.