Prototype Electric Vehicle Research Articles

Control Allocation for Hybrid Braking Considering Dynamic Battery Behaviour

This work deals with the problem of maximizing energy recovery while optimizing braking capability of high-performance electric vehicles under given actuator constraints. A scalable, real-time capable concept using a complementary filter with an additional daisy chain for the control allocation between hydraulic brakes and electric motors is proposed. Furthermore, a model inversion approach that derives necessary battery limits while trying to decouple the wheel speed control loop from the protection loop of a modern battery management system is described. The hybrid braking control architecture is studied in simulation and validated in a prototype electric vehicle by highly dynamical driving manoeuvres.

Power and Torque Analysis in Electric Vehicle Prototype Design

Automotive developments led to increased demand for fuel. Vehicle need fossil fuels to move them, while the fossil energy in this world is decreasing over time because fossil energy cannot be renewed. This has triggered the development of the use of electrical energy in the transportation system as a substitute for fossil fuels whose energy source is from renewable energy such as biomass energy (such as methane), hydropower, geothermal power, wind energy, and solar energy. One method that can be done to reduce the use of fossil energy is by utilizing electrical energy as an energy source in cars. In this study, an electric car prototype was designed using a three-phase induction motor with 3 HP power as the main driving force. To find out the power consumption and torque produced, it is necessary to analyze the calculation of power and torque when loaded and without load. In this research, the electric car prototype uses load variants, 40 kg, 60 kg, and 100 kg. Where the maximum torque that can be generated by the motor when no load is 9.94 Nm and when it is loaded is a variation of the load of 100 kg of 11.80 N.m. Calculation of the maximum power that can be generated by the motor when no load is 1976.94 watts and when loaded is a variation of 100 kg of 1202.59 watts. The data from the calculation of torque is inversely proportional to power, where the greater the power, the smaller the torque produced.

Evaluation of driver stress level with survey, galvanic skin response sensor data, and force-sensing resistor data

Thousands of lives are lost in traffic accidents every year, and most traffic accidents are caused by driver errors. Causes and impairments such as fatigue, inattentiveness, alcohol usage, stress, and drugs are the main factors of these accidents. When a driver is subject to changing and complicated driving tasks in traffic, he or she should be able to assure driving authority to prevent potential hazards and accidents. In this context, the purpose of this study is to determine the stress level of the driver when driving in urban traffic in such situations requiring delegation of driving authority. Thus, the work combines stress questionnaire and galvanic skin response sensor to validate results and fuses with a force-sensing resistor. In this study, a prototype electric vehicle is equipped with sensors providing various drivers’ data including the responses of a force-sensing resistor sensor while galvanic skin is being collected on a specified route. At the end of the trip, the stress level of the drivers is determined by the collected data. Results indicate that the galvanic skin sensor stress results are consistent with the results of the survey with an average accuracy of 87.5%. The force-sensing resistor sensor is only used to determine gender stress. And the force-sensing resistor sensor gender-stress results are consistent with results of the survey with an accuracy of 100%. These results are used to validate the results of post-driving stress survey evaluated by SPSS 23.0 windows statistics software. Data analysis is particularly focused on demographic properties of participators, factor analysis, reliability tests, correlation, T-test, and one-way analysis of variance.

Performance enhancement of electric vehicle traction system using FO‐PI controller

This work improves the performance of an electric vehicle (EV) traction system by using non-linear fractional-order proportional–integral (FO-PI) controller. The functionality of FO-PI controller is benchmarked against integer-order proportional–integral (IO-PI) controller. A 400 V, 6.6 Ah Li-ion battery bank is designed to power an indirect field-oriented induction motor driven prototype EV traction system. The appeal of this study is to reveal the simplicity, robustness, and effectiveness of FO-PI speed regulator for EV traction system. The efficacy of FO-PI speed regulator for EV applications is validated through rigorous experimentation. The FO-PI controller due to its non-linear nature proves to be more robust and effective under variation of a system's parameters and external disturbances as compared to IO-PI controller. Furthermore, the experimental results show that FO-PI control strategy provides higher torque per amp output while maintaining better voltage and state-of-charge profiles of the Li-ion battery bank.

Comparative study of reduced order equivalent circuit models for on-board state-of-available-power prediction of lithium-ion batteries in electric vehicles

Battery management systems (BMS) are responsible for the reliable and safe operation of lithium-ion battery packs in electric vehicles (EVs). State-of-Charge (SoC), State-of-Health (SoH) and State-of-Available-Power (SoAP) are the major battery states that must be determined by means of so-called monitoring algorithms. In this study, a comparative study of a wide range of impedance-based equivalent circuit models (ECMs) for on-board SoAP prediction is carried out. In total, seven dynamic ECMs including ohmic resistance, RC-elements, ZARC-elements connected in series with a voltage source are implemented. The investigated ECMs are verified under varying conditions (different temperatures and wide SoC range) in a model-in-the-loop (MiL) environment using real vehicle data obtained in an EV prototype and current pulse tests. In this context, LIBs at different aging states using various active materials (NMC/C, NMC/LTO, LFP/C) are investigated. Furthermore, the current dependence of the charge transfer resistance is considered by applying the Butler-Volmer equation. The dependence of voltage estimation and SoAP prediction accuracy for different prediction time horizons on SoC, temperature and applied current rate is examined comprehensively.

Practical implementation of the concept of converted electric vehicle with advanced traction and dynamic performance and environmental safety indicators

The objective of the work presented in this paper is to describe the implementation of the technical solutions have been developed, with regard to structure, composition, and characteristics, for an experimental prototype of an electric vehicle which has been converted from a conventional vehicle. The methodology of the study results is based on the practical implementation of the developed concept of the conversion of conventional vehicles into electric vehicles. The main components of electric propulsion system of the experimental prototype of electric vehicle are developed and manufactured on the basis of computational researches, taking into account the criteria and principles of conversion within the framework of presented work. The article describes a schematic and a design of power conversion and commutation electrical equipment, traction battery, electromechanical transmission. These results can serve as guidance material in the design and implementation of electric propulsion system (EPS) components of electric vehicles, facilitate the development of optimal technical solutions in the development and manufacture of vehicles, including those aimed at autonomy of operation and the use of perspective driver assistance systems. As part of this work, was suggested a rational structure for an electric vehicle experimental prototype, including technical performance characteristics of the components of EPS.

Active equalization system based on Flyback converter for the battery modules of the electric vehicle prototype of Formula Student Uniovi team

Active equalization system based on Flyback converter for the battery modules of the electric vehicle prototype of Formula Student Uniovi team

Evaluating a heart rate regulation system for human–electric hybrid vehicles

Heart rate regulation systems for human–electric hybrid vehicles (such as electric bicycles) might help to promote physical activity and prevent overexertion. To date, there has not been a thorough evaluation that shows the benefits and limitations of such a system compared to a conventional assistance. In this article, the authors evaluated a control system that adjusts the motor torque of a four-wheeled human–electric hybrid vehicle prototype (QuadRad) to maintain the heart rate of the cyclist within user-specified limits. A randomized block design was used to validate the system. A total of 42 persons performed a 70-min test cycle with the QuadRad on a stationary test rig. Participants were equally divided into 14 blocks based on an estimate of their fitness level. Within each block, participants were randomly assigned to one of three experimental groups. The three groups compared the following: (1) regulation of subjectively perceived exertion using standard assistance, (2) regulation of heart rate using standard assistance and (3) regulation of heart rate using control system. A non-parametric Kruskal–Wallis test showed significant differences between the three groups for mean absolute deviation of the heart rate from the reference heart rate [Formula: see text][Formula: see text]. Post hoc comparison showed that [Formula: see text] was significantly lower for groups 2 [Formula: see text] and 3 [Formula: see text] compared to group 1 and similar between groups 2 and 3 [Formula: see text]. Time out of the heart rate zone [Formula: see text] was significantly different between all groups [Formula: see text]. Post hoc analysis showed that [Formula: see text] was lower for groups 2 [Formula: see text] and 3 [Formula: see text] compared to group 1 and similar between groups 2 and 3 [Formula: see text]. The results indicated that cyclists can use the system to maintain their heart rate within self-chosen limits without having to monitor their heart rate or manually change the assistance mode.

UPS unveils delivery vehicle with fuel cell range-extender for trial in California

Logistics giant UPS will deploy a prototype electric vehicle featuring a fuel cell range-extender in its Rolling Laboratory fleet of alternative fuel and advanced technology vehicles. UPS is working with the US Department of Energy and other partners to design an innovative zero-emissions, Class 6 medium-duty delivery truck that can match the same route and range requirements as the company's conventional vehicles.

Optimal Design of Electric Vehicle Power System with the Principle of Minimum Curb Mass

With the lightweight idea, an optimal design is developed for the powertrain of electric vehicles (EVs) to reduce the power consumption while maintaining excellent performance. Based on a prototype EV, the paper takes minimum curb mass as design principle, a single charge trip range mileage and whole life cycle of battery as constraints. The uniqueness of the design is the consideration in the selection of base speed and the associated change of motor and battery mass. The design is developed in two stages. With power and torque demand ensured, the first carries on the calculation and configuration of dynamic parameters to minimize curb mass for energy saving. The second stage verified the depth of discharge to guarantee good durability. The superiority of the design is demonstrated by comparing optimization results with original values.

Simple supercapacitor charging scheme of an electric vehicle on small-scale hardware simulator: a prototype development for education purpose

Supercapacitor is one of electrical energy sources that have faster charging-discharging times when compared to other power sources, such as battery and fuel cell. Therefore, it is often used as an additional power source in an electric vehicle. In this paper, a prototype of small-scale electric vehicle simulator (EVS) is built and a simple charging scheme of supercapacitor is used for education purpose. EVS is an electric vehicle prototype which can show the vehicle’s powertrain on small-scale configuration. Main components of this device are two direct current motors (DCMs) with a linked axis of rotation. Therefore one of them will be able to act as a generator. The supercapacitor charging scheme is employed by controlling the relays. The hardware experimental result shows that the averages of charging current are proportional to the maximum slope angle of the road profiles. This scheme is simple due to the EVS utility and it is useful for education purpose.

연료전지 철도차량 적용을 위한 인터리브드 다상 승압형 컨버터 제어

Fuel cell power generation system, unlike conventional energy sources, converts chemical energy into electrical energy through electrochemical reaction of hydrogen and oxygen. This paper presents the control of interleaved multi-phase boost converter as the feasibility study on small-scale prototype electric railway vehicle application using fuel cell generation system. PSIM simulation program is to be used to implement the modeling of the electrical fuelcell as well as traction motor control with interleaved multi-phase boost converter. Comparing the input current ripple rate, two-phase interleaved boost converter is less than the boost converter. But the more multi-phase not less proportional to the ripple factor. we confirmed that the amplitude of the input current ripple rate of converter depend on duty ratio.

An efficient auxiliary system controller for Fuel Cell Electric Vehicle (FCEV)

This article presents analysis of the systems in a Fuel Cell Electric Vehicle (FCEV) prototype with the aim of determining if it is possible to increase vehicle efficiency through strategic control of the auxiliary systems. To accomplish this, an overview of the vehicle design is given as well as an in depth analysis of the powertrain efficiency and control strategy. This leads to the development of a modified powertrain control algorithm which also oversees and controls the auxiliary power demand in real-time. The auxiliary control aspect of this algorithm follows predefined rules as determined through analysis of the individual systems, and based on the definitions of flexible useful and wasteful auxiliary power. The simulation results show that the proposed technique, applied to FCEV air conditioning system alone, improves the fuel economy in the neighborhood of 3.4% compared to conventional bang-bang controller. This magnitude of energy reduction is very significant in the automotive industry, especially when considering the number of vehicles in use in today's transportation sector. The resulting algorithm is adaptable to a number of different types of auxiliary systems and primary power sources, thereby not specifically tied to the fuel cell architecture for which it is developed.

Enhancing vehicle cornering limit through sideslip and yaw rate control

Fully electric vehicles with individually controlled drivetrains can provide a high degree of drivability and vehicle safety, all while increasing the cornering limit and the ‘fun-to-drive’ aspect. This paper investigates a new approach on how sideslip control can be integrated into a continuously active yaw rate controller to extend the limit of stable vehicle cornering and to allow sustained high values of sideslip angle. The controllability-related limitations of integrated yaw rate and sideslip control, together with its potential benefits, are discussed through the tools of multi-variable feedback control theory and non-linear phase-plane analysis. Two examples of integrated yaw rate and sideslip control systems are presented and their effectiveness is experimentally evaluated and demonstrated on a four-wheel-drive fully electric vehicle prototype. Results show that the integrated control system allows safe operation at the vehicle cornering limit at a specified sideslip angle independent of the tire-road friction conditions.

Design of a very light L7e electric vehicle prototype

Due to the diminishing fossil fuel and strict emission standards, electric vehicles are becoming more popular day by day. In many foundations, light electric vehicle prototypes are being built; however, their cost is generally very high. This paper introduces novel approaches for the design and manufacturing of a light electric vehicle prototype with very low cost. General design philosophy of such a prototype is presented. A theorem for the synchronization problem of two independent electric motors is proposed. Gear ratio optimization for acceleration performance, gradability, and top-speed of such electric vehicles is mentioned. Novel simplified suspension-steering kinematic design procedures are proposed. Approaches for mechanical design of a very light electric vehicle prototype are presented. The important concerns in those design approaches are low cost manufacturing processes and lightness by considering passive safety. A realistic impact loading scenario is proposed to determine the maximum force acting through a wheel of a vehicle. After the road tests performed, test results are presented and discussed. Finally, range of the car under various conditions is given.

Analisa Perbandingan Karakteristik Bodi dan Chassis pada Prototype Kendaraan Listrik

In the design of electric vehicles prototype, there are many things that must be taken into account and considered to be used completely without danger and failure in materials. In general, they are the design of body, chassis or frame design, the design of the transmission system, the design of the engine (motor), and the design of electrical installations. Vehicle chassis monocoque has a lighter weight compared to the vehicle chassis with a ladder. The weight of the vehicle has a considerable effect on the efficiency of the motor in which the motor work harder. Body vehicle glass fiber and carbon fiber also has a weight that is much different. With the same frame, the vehicle weight is obtained with a machine that utilizes carbon fiber body and fiber glass 43 kgf and 54 kgf. Excess carbon fiber monocoque chassis can be combined to produce the weight of the vehicle 36 kgf.

Desarrollo de una máquina eólica de doble turbina de eje vertical para la generación de energía en un auto eléctrico

Se presentan los resultados del desarrollo e integración a un vehículo eléctrico de un prototipo de máquina eólica conformada por dos turbinas de eje vertical tipo Savonius soportadas en los extremos de sus ejes sobre un bastidor y un sistema de piñones, que además de mantenerlas sincronizadas, actúan como elevador de revoluciones para hacer funcionar un generador eléctrico y así extraer corriente eléctrica de ellas. La máquina eólica se instaló en la parte frontal de un prototipo de auto eléctrico diseñado especialmente; así, mientras el auto está en movimiento, el viento que golpea su parte frontal hace girar las turbinas generando corriente eléctrica; se recolectaron datos como velocidad, revoluciones de las turbinas, voltajes y amperaje para realizar el respectivo análisis y conocer el rendimiento del nuevo sistema eólico propuesto.

Integral Sliding Mode for the Torque-Vectoring Control of Fully Electric Vehicles: Theoretical Design and Experimental Assessment

This paper presents an integral sliding mode (ISM) formulation for the torque-vectoring (TV) control of a fully electric vehicle. The performance of the controller is evaluated in steady-state and transient conditions, including the analysis of the controller performance degradation due to its real-world implementation. This potential issue, which is typical of sliding mode formulations, relates to the actuation delays caused by the drivetrain hardware configuration, signal discretization, and vehicle communication buses, which can provoke chattering and irregular control action. The controller is experimentally assessed on a prototype electric vehicle demonstrator under the worst-case conditions in terms of drivetrain layout and communication delays. The results show a significant enhancement of the controlled vehicle performance during all maneuvers.

Influence of the Design Parameters of Electric Vehicles in the Optimization of Energy Efficiency in Urban Routes

The analysis and decision making on design, behavior and use of a prototype electric vehicle is the main focus of this paper. For this purpose, a prototype electric vehicle was modelled. The dimensional parameters needed to create the model were obtained by measurements, calculations and approximations. Subsequently, a route to be travelled by the vehicle was determined and a simulation of the vehicle on that route followed. Different modifications in the model were performed to compare their results with the original model through simulation in software Adams/Car. In this paper, we show the design criteria for electric vehicles to optimize engine power, weight, battery and vehicle performance according to the characteristics of typical urban routes.

Finite Element Simulation of Front Suspension Lower Arm of MacPherson Type Based on ANSYS

In this paper, the Xiali car Mcpherson type front suspension lower arm as the main research object, research the Xiali car converted to electric vehicles, the lower arm, internal stress distribution of structure on the lower arm, and on the basis of optimization design is carried out with ANSYS software. The last judgment andevaluation of prototype vehicle and electric vehicle arm stress, strain distribution and variation of structure on the lower arm, the topology optimization analysis is carried out, the lower arm to meet the strength and stiffness of the structure at the same time, meet the requirements of lightweight design.