The use of in-car networked electronic controller units (ECUs) for monitoring and control of various vehicle subsystems has become a common practice among the automotive manufacturers. In this chapter, the author surveys one of the most popular in-car networking technologies, the Controller Area Network (CAN), as well as newer and emerging in-car network technologies called FlexRay and Media-Oriented System Transport (MOST). Currently, these networks are deployed for in-car applications such as engine diagnostics, and infotainment systems. In this chapter, however, the author extends the use of these embedded vehicular networks by proposing to remotely monitor and control the vehicles through them, in order to realize safety and driver assistance related applications. To accomplish this task, additional technologies such as real-time wireless communications and data security are required, and each of them is introduced and described in this chapter.
TopIi. Background
The Controller Area Network (CAN) (CiA, 2008; Audi CAN-bus, 1998) is a serial bus communications protocol developed by Bosch in around1983. CAN is a standard suitable for efficient and reliable communication between sensors, actuators, controller, and other nodes in real-time applications. Since then, CAN has evolved to become the de facto low-cost standard in a large variety of networked embedded control systems. Many of the early deployments of CAN are found in automotive vehicles. To-date, however, CAN has been used in a variety of application domains such as transportation (e.g. trains), manufacturing (e.g. process automation), construction (e.g. structural monitoring), agriculture (e.g. agriculture equipment), healthcare (e.g. medical devices), entertainment (e.g. arcade game machine), and even in the control of scientific apparatus (e.g. proton accelerators). In this chapter, however, we will only focus on applications of CAN within the automotive vehicles (see Figure 1).
Figure 1. CAN Replaces traditional mesh wiring in a vehicle
In 2007, it is estimated that sale of vehicular CAN nodes has reached more than 600 million each year (Johansson, K.H., Törngren M., & Nielsen L., 2005). Looking ahead, the number of CAN nodes deployed in automotive vehicles is expected to increase substantially as by 2008, all new vehicles sold in the US will be required to be CAN-compliant, in particular, all new vehicles are to equip with CAN-based diagnostic system. Moving forward, the number of automotive manufacturers adopting CAN for in-vehicle embedded data communications and control is expected to increase as more Japanese models have started to adopt CAN-based technologies which are relatively low-cost and a well-established standard.
In the rest of this chapter, we will discuss the various system components involved to accomplish the goal of monitor and control vehicle remotely and securely. We first elaborate the basis and the general technology landscape of CAN deployments in automotive industry; followed by an overview of the deployment of in-car CAN networks. Next we discuss the various existing and future applications that make use of the CAN data. The two key technologies components needed to achieve secure remote vehicle monitoring, namely data security and wireless communications are discussed toward the end of the chapter.
TopIii. Overview Of Can Technologies
An overview of CAN technologies is presented in this section.