Abstract-In this paper, the design of a discrete-time slidingmode controller based on Lyapunov theory is presented along with a robust disturbance observer and is applied to a piezostage for high-precision motion. A linear model of a piezostage was used with nominal parameters to compensate the disturbance acting on the system in order to achieve nanometer accuracy. The effectiveness of the controller and disturbance observer is validated in terms of closed-loop position performance for nanometer references. The control structure has been applied to a scaled bilateral structure for the custom-built telemicromanipulation setup. A piezoresistive atomic force microscope cantilever with a built-in Wheatstone bridge is utilized to achieve the nanonewtonlevel interaction forces between the piezoresistive probe tip and the environment. Experimental results are provided for the nanonewton-range force sensing, and good agreement between the experimental data and the theoretical estimates has been demonstrated. Force/position tracking and transparency between the master and the slave has been clearly demonstrated after necessary scaling.

A Vehicular Ad-hoc Network (VANET) comprises a group of moving or stationary vehicles connected by a wireless network. VANETs play a vital role in providing safety and comfort to drivers in vehicular environments. They provide smart traffic control and real-time information, event allocation. VANETs have received attention in support of safe driving, intelligent navigation, emergency and entertainment applications in vehicles. Nevertheless, these increasingly linked vehicles pose a range of new safety and security risks to both the host and its associated properties and may even have fatal consequences. Violations of national privacy and vehicle identities are a major obstacle to introducing forced contact protocols in vehicles. Location privacy refers to the privacy of the vehicle (driver) and the location of the vehicle. Whenever a vehicle sends a message, no one but authorized entities should know their real identity and location of the vehicle. All the messages sent by the vehicle must be authenticated before processing, hence location privacy is an important design aspect to be considered in VANETs operations. The novelty of this paper is that it specifically reviews location privacy in VANETs in terms of operational and safety concerns. Furthermore, it presents a critical analysis of various attacks, identity thefts, manipulation and other techniques in vogue for location privacy protection available in state-of-the-art solutions for VANETs. The efforts in this paper will help researchers to develop a great breadth of understanding pertaining to location privacy issues and various security threats encountered by VANETs and present the critical analysis of the available state-of-the- art solutions to maintain location privacy in VANETs.

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