Rakesh N. Rao

Bio: Rakesh N. Rao is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Active safety & Headway. The author has an hindex of 1, co-authored 1 publications receiving 8 citations.

Effect of Vehicle-to-Vehicle Communication Latency on a Collision Avoidance Algorithm for Heavy Road Vehicles*

Abstract: Active safety is of utmost importance in heavy road vehicles due to the relatively higher number of fatalities encountered in their accidents. Vehicle-to-Vehicle (V2V) technology, which is seen as a future of connected vehicles, can potentially complement onboard sensing to reduce the time taken for detection, and to plan the path with the information available from road side units (RSU). This paper investigates the effect of Iatency in (V2V) communication on a collision avoidance algorithm developed for heavy road vehicles. Experiments performed on a Hardware-in-Loop (HiL) setup were used to evaluate the effect of Iatency for various scenarios. It was found that Iatency had a counterbalancing effect on vehicle spacing and relative longitudinal speed that led to insignificant changes in the final spacing. Further, a sensitivity analysis done at different host vehicle longitudinal speeds demonstrated the need of a variable time headway.

Performance Analysis for the Coexistence of Radar and Communication in VANETs

Abstract: Active safety plays more and more important role on road due to high number of traffic accidents, which requires vehicular safety sensors to collect road environment information from time to time. To exchange the results of sensors, vehicular ad hoc networks (VANETs) have attracted much attention from both industry and academia. In this paper we propose a new coexistence model of vehicular long range radar (LRR) operating at 77GHz and dedicated short range communication (DSRC) system, in which each vehicle detects forward and transmits the detection results backward. A transmitter distribution strategy is also proposed. Then we calculate the interference propagation distance and the upper bound of coverage probability according to IEEE 802. 11p standard and the strategy above. Finally, we fuse the detection range of typical vehicle pair and calculate the mean of effective joint detection range. Our analysis and simulation results show that the coexistence of the two systems can effectively improve the detection range of a single vehicle.

Communication Latency and Speed-Dependent Minimum Time Headway for Connected Heavy Road Vehicle Collision Avoidance

Abstract: Advanced Driver Assistance Systems in heavy commercial road vehicles (HCRVs) have become necessary with the increasing contribution of HCRVs to road accident fatalities, where human factors form the major contributor. Collision avoidance systems can help in reducing fatalities through automated braking when required. This study focused on the development of a framework for the computation of the minimum time headway, for a Vehicle-to-Vehicle (V2V) communication-based collision avoidance system for HCRVs, that must be maintained through automated braking to avoid a collision. The framework, as well as the developed Collision Avoidance Algorithm (CAA), considers critical attributes of an HCRV such as significant load variations and brake actuator dynamics. Further, the time headway formulation varies with the initial longitudinal speed and considers communication latency. Experiments were conducted in a Hardware-in-Loop test setup to evaluate the efficacy of the proposed formulations. It was observed that the incorporation of communication latency and initial longitudinal speed explicitly in the time headway formulation maintained the desired final spacing between the vehicles, over a range of communication latencies and various host vehicle longitudinal speeds, which was not the case when the above factors were not considered.

Effect of Packet Loss on a Connected Heavy Vehicle Collision Avoidance Algorithm

Abstract: Advanced Driver Assistance Systems in Heavy Commercial Road Vehicles are of increasing importance due to their high potential in reducing road accidents, where human error is the major contributor. A Vehicle-to-Vehicle communication-based Collision Avoidance Algorithm (CAA) can help in reducing these accidents by complementing the onboard sensors and applying brakes automatically upon detecting a threat. However, due to the wireless nature and dynamic topology of this communication network, packet loss is a major challenge for safety-related applications like collision avoidance. Hence, the effect of packet loss on the performance of CAA was investigated using a Hardware-in-Loop experimental platform in this paper. It was observed that the desired final spacing was maintained but, early braking was observed when the host vehicle followed the lead vehicle at close distances.