# Adaptive Cruise Control in Electric Vehicles with Field-Oriented Control
## 1 Introduction  
The transportation sector has great importance nowadays; there are more than a billion vehicles in the whole world, and the number is increasing exponentially, with expectations that in 10 years there will be more than 2 billion vehicles in the world [1]. The mainly used vehicles are those powered by internal combustion engines (ICE). Even though the first electric vehicle (EV) was created in the 1830s, after the development of the batteries, electric vehicle growth stopped in the 1900s due to the development of ICE-powered vehicles. ICE vehicles had great success because fossil fuels had lower prices than batteries; this is still accurate nowadays too, with the series production of ICE vehicles, so the overall price of the ICE vehicles was reduced. Additionally, the batteries had a low capacity and power density at that time, compared with gasoline, and ICE vehicles could travel long distances [2]. Over the past decades, climate changes and pollution issues have been considered, and the transportation sector is a pollution source because of the greenhouse gas emissions generated by the internal combustion engines. Given these issues, and also adding the limited resources of fossil fuels, the vehicle industry is searching for an alternative solution for transportation. Electric vehicles are a perfect alternative for transportation, without greenhouse gas emissions and without fossil fuel consumption. So, in the last years electric vehicles have gained more interest because they are a suitable replacement for the classic vehicle with an internal combustion motor. Electric vehicle growth is also based on the development of batteries. Lithium batteries have a higher power density and capacity than other batteries and made possible the use of electric vehicles, but there is still a problem about the range and time required for the battery to be charged [2; 3; 4]. The major advantages of electric vehicles over ICE vehicles are the reduced emissions of carbon monoxide emissions and that there is the higher efficiency and performanceof the electric motor than the ICE engine because the electric traction system has fewer mechanical parts and gears, which reduces a huge number of mechanical losses and, also, lowers maintenance costs [3]. An efficient driving style or eco-friendly driving style is an important aspect considered for ICE vehicles to reduce fuel consumption, and it is even more important for EVs because it can extend the driving range. Driving style is particular to each driver, but there have been some driving assistant systems developed that help drivers have a better driving experience. One of the popular driving assistant systems is cruise control (CC), which maintains a constant vehicle speed, improves fuel economy, and increases driver comfort during long-distance driving [5; 6; 7; 8; 9; 10; 11]. Cruise control is a driving assistance system that allows the driver to set a desired speed, and the system ensures that the vehicle has a set speed so the driver does not have to keep the acceleration pedal pushed to maintain a certain speed; this is the basic cruise control application [6; 8; 10]. The first cruise control system was developed in 1950 by the engineer [PERSON], who patented a \"Speed Control Device for Resisting Operation of the Accelerator\" [12]. The first generation of cruise control systems had only mechanical parts used to keep the throttle in a fixed position to maintain a constant speed. In the following years, the system was improved with electronic components, such as speed sensors, a microcontroller for control, and providing a user interface; therefore, the throttle actuator was easier to control in various positions for different values of speed [10]. An updated version of the cruise control system is the adaptive cruise control (ACC) system; cruise control controls the speed of the vehicle, but adaptive cruise control controls the speed but also the distance between the host vehicle and a leading vehicle [8].