Longitudinal Control

Introduction The public highway systems are used to transport a constantly increasing number of goods and people. In spite of that high increase in traffic, the number of fatal accidents is falling yearly, because of the ever increasing use of technology to develop safer vehicles. Meanwhile, the environmental impact of each vehicle decreases proportionally in that technology partly compensates for the environmental pressure exerted by the increase in number of vehicles on the roads. On the other hand, technology still has not been used to alleviate another problem caused by the number of vehicles on the road: road congestion. Because adding more lanes is becoming less desirable or practical, means must be found to increase the capacity of the existing network. This must be done while keeping in mind the safety of the travelers. Enters collaborative driving. For many years, this field has received increasing interest around the world. Research on collaborative driving strives to create vehicles that are able to cooperate in order to navigate through urban traffic by using communications. In this paper, we will describe three degrees of collaborative driving, and what challenges each offers to system designers. We will also review some of the research made worldwide to meet these challenges. Definitions To better understand the discussed matters, the reader should understand some basic concepts. Collaborative driving is a research domain which aims to create automated vehicles which collaborate with another in order to navigate through traffic. Collaborative driving is different from automated highway systems (AHS) in that the vehicles in AHS do not directly cooperate to achieve safe and efficient driving. A platoon is a group of vehicles whose actions on the road are coordinated by the mean of communications. The first vehicle of a platoon is called the platoon leader. Its role is to manage the platoon and guide it on the road. We distinguish three degrees of collaborative driving: a) Longitudinal control, in which the platoon members' controllers are controlling the speed and distance of each member vehicule to the preceding one, leaving the steering to the human driver, b) Semi-autonomous control, in which the platoon members are automatically controlled, but the leading vehicle must still be driven by humans, and c) Fully-autonomous control, in which all platoon members, including the leading vehicule, are autonomously controlled until the platoon is disbanded. Introduction As has been stated earlier, the longitudinal control of a platoon …