# A Review of Digital Twin Technology for Electric and Autonomous Vehicles
## 4 Current Issues in Electric Vehicles
### Tracking and Monitoring  
The use of EVs leads to important changes in mobility. Numerous advantages are linked to using EVs, including zero emissions, improved fuel economy, and lower running costs, making them perfect cars for everyday use. Security concerns, route planning, and battery charging are all challenges that vehicle monitoring systems may help to address. When planning long trips, optimal tracks, battery life, state of health, and charging time have to be planned and monitored.  
An increasing number of charging stations are appearing. Since they are not as widely spread and prominent as gas stations, regular route planning and daily charging station  
Figure 6: Current issues in electric vehicles.  
check-ups are necessary. The issue of range anxiety is still critical in EVs and needs to be considered in the upcoming research. [PERSON] et al. [49] proposed a novel framework to solve this issue by introducing a real-time mixed SoC estimation algorithm. The proposed system was implemented in an advanced driver assistance system. The proposed modified method includes the recalibration technique for estimating the battery state of health (SoH), the initial battery SoC, and the effective battery capacity, while considering external parameters and environmental factors, such as traveling, vehicles, traffic congestion, and driver behaviors, to make the model more accurate than the traditional models available in the literature where the environmental conditions and driver behaviors are not considered. Both laboratory and field tests have been conducted using a Nissan Leaf and, as a result, the SoC estimation of lithium-ion batteries improved with great accuracy and high real-time capability. In [50], a discrete scheduling process was formulated to track arbitrary power profiles and control charging, limiting it to the maximum rated power. The coordinated charging of PEVs is formalized by considering the realistic case of PEVs with different charging rates. In addition, a novel algorithm has been developed to ensure plug-in EV charging without the need for a central aggregator. It ensures that the power profile imposed by the power utility is tracked and not exceeded while maximizing user comfort. The effectiveness of the algorithm has been demonstrated in realistic scenarios, with a heterogeneous PEV population, but no performance comparison with other methods has been provided.  
Thus, vehicle monitoring systems greatly affect research and development and improve the operations of the industrialization of EVs. In addition, [PERSON] et al. [51] designed a remote monitoring system for EVs, i.e., a combination of remote monitoring platforms and onboard terminals installed on the vehicle. On the contrary, with respect to [50], the idea was to aggregate the data from the onboard terminal, such as the battery status, temperature, SoC, running status, etc., and send them to the server cluster model for processing and monitoring. This model can improve communication reliability and enhance the real-time performance of the system. The system structure of the electric vehicle remote monitoring system is based on CAN and GPRS technology and aims to provide a certain guiding significance for the design of remote real-time monitoring systems for new energy vehicles. It is necessary to monitor the parameters of EVs to avoid electrical malfunctions because problems of this type are costly to solve. In this context, adopting the DT concept can provide solutions to the discussed issues about EV monitoring and tracking.