# Adaptive Cruise Control in Electric Vehicles with Field-Oriented Control
## 1 Introduction
Advanced cruise control systems focus on accelerating or braking so that the vehicle speed is constant at the set value but, also, a safety driving distance is ensured. The internal combustion motor is accelerated if needed, through the throttle actuator, and braking is performed using a braking system [10; 11; 13]. For electric vehicles, the implementation of cruise control is a little different because the electric motor can accelerate or brake, in a defined range, based on the value of the current supplied through the inverter. The electric motor control can generate driving signals to accelerate, brake, or, even, to work as a generator in regenerative braking mode. Therefore, in electric vehicles, the cruise control system should relate to the motor control system for high efficiency [10; 11; 13; 14; 15; 16; 17]. To analyze the speed of a vehicle is important to know how the motor works and how its speed is controlled. In the case of an electric vehicle, there is an electric motor. Electric motors have a great advantage over internal combustion motors, the ability to work as a generator, so that regenerative braking is possible in electric vehicles. For a propulsion system, there are some specific requirements that the electric motor must have, such as high power and torque density, wide speed range, high torque for start and hill climbing, and a wide range for constant power. Based on these requirements, the following electric machines can be used in electric vehicles: DC machines, induction machines, switched reluctance machines, brushless DC machines, and permanent magnet synchronous machines. BLCD and permanent magnet synchronous machines proved to have a higher efficiency but with a higher cost, and with the possibility of the demagnetization of the permanent magnets [18; 19; 20; 21]. For an electric propulsion system, it is important to control the torque and speed of the electric machine so that the vehicle can overcome the starting torque and to deliver the desired speed. The control of an induction machine can be performed in many ways, but for higher efficiency, two control strategies are widely used: field-oriented control (FOC) and direct torque control (DTC) [20]. Field oriented control ensures the proper control of an induction machine, using a d-q representation to control variables as dc quantities using basic PI controllers [22; 23]. Field oriented control can be implemented sensorless, many papers have presented different methods [24; 25; 26; 27]. Additionally, field-weaking control can be applied along with field-oriented control to achieve a higher speed [28; 29]. Nowadays, the development of electric vehicles determines the implementation of new driving assistance systems or the adaptation of the older ones so that they can be successfully used also in electric vehicles. Being a useful system, cruise control adaptation for electric vehicles is required. This study presents how an adaptive cruise control system interacts in an electric vehicle with an induction machine controlled with an indirect field-oriented method. In the literature, the two systems are presented and discussed, but the relation between them and how the two systems are connected is not mentioned anywhere. That is the goal and novelty of this paper, to illustrate the function of an adaptive cruise control system in an electric vehicle powered by an induction machine controlled with an indirect vector control in the case of the cruise control scenario. This paper presents only the electric part of the powertrain system of an electric vehicle; no mechanical components as a brake, distribution, or wheels were considered for this study. The contributions of this paper are the following:  
* Illustrates how adaptive cruise control works for an electric vehicle having an induction motor controlled in an indirect field-oriented manner. * Presents the relationship between an adaptive cruise control system and field-oriented induction machine control system in the case of an electric traction system.