Control Systems Engineering

The use of electric vehicles (EVs) is viewed as an attractive option to reduce CO2 emissions and fuel consumption resulted from transport sector, but the popularization of EVs has been hindered by the cruising range limitation and the charging process inconvenience. Energy consumption characteristics analysis is the important foundation to study charging infrastructures locating, eco-driving behavior and energy saving route planning, which are helpful to extend EVs’ cruising range. From a physical and statistical view, this paper aims to develop a systematic energy consumption estimation approach suitable for EV actual driving cycles. First, by employing the real second-by-second driving condition data collected on typical urban travel routes, the energy consumption characteristics analysis is carried out specific to the microscopic driving parameters (instantaneous speed and acceleration) and battery state of charge (SOC). Then, based on comprehensive consideration of the mechanical dynamics characteristics and electric machine system of the EVs, a set of energy consumption rate estimation models are established under different operation modes from a statistical perspective. Finally, the performance of proposed model is fully evaluated by comparing with a conventional energy consumption estimation method. The results show that the proposed modeling approach represents a significant accuracy improvement in the estimation of real-world energy consumption. Specifically, the model precision increases by 25.25% in decelerating mode compared to the conventional model, while slight improvement in accelerating and cruising mode with desirable goodness of fit.

Electric vehicles’ energy consumption estimation with real driving condition data

Aiming at the braking energy feedback control in the optimal energy recovery of the two-motor dual-axis drive electric vehicle (EV), the efficiency numerical simulation model based on the permanent magnet synchronous motor loss was established. At the same time, under different speed and braking conditions, based on maximum recovery efficiency and data calculation of motor system, the optimization motor braking torque distribution model was established. Thus, the distribution rule of the power optimization for the front and rear electric mechanism was obtained. This paper takes the Economic Commission of Europe (ECE) braking safety regulation as the constraint condition, and finally, a new regenerative braking torque distribution strategy numerical simulation was developed. The simulation model of Simulink and CarSim was established based on the simulation object. The numerical simulation results show that under the proposed strategy, the average utilization efficiency of the motor system is increased by 3.24% compared with the I based braking force distribution strategy. Moreover, it is 9.95% higher than the maximum braking energy recovery strategy of the front axle. Finally, through the driving behavior of the driver obtained from the big data platform, we analyze how the automobile braking force matches with the driver’s driving behavior. It also analyzes how the automobile braking force matches the energy recovery efficiency. The research results in this paper provide a reference for the future calculation of braking force feedback control system based on big data of new energy vehicles. It also provides a reference for the modeling of brake feedback control system.

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Energy Recovery Strategy Numerical Simulation for Dual Axle Drive Pure Electric Vehicle Based on Motor Loss Model and Big Data Calculation

Tribology of electric vehicles: A review of critical components, current state and future improvement trends

https://opus.lib.uts.edu.au/bitstream/10453/60379/1/MSSP_paper_Revised.pdf

Powertrain dynamics and control of a two speed dual clutch transmission for electric vehicles

Fully electric vehicles and range-extended electric vehicles can be characterised by a multitude of possible powertrain layouts, many of them currently under investigation and comparison. This contribution presents a novel clutchless seamless four-speed transmission system which can be concurrently driven by two electric motor drives, for use in fully electric vehicles or electric axles for through-the-road parallel hybrid electric vehicles. The transmission system allows the electric motors to work in their high efficiency region for a longer period during a typical driving schedule. This paper describes the layout of the novel transmission system, the equations for modelling its dynamics and the criteria for the selection of the best gearshift maps for energy efficiency. Finally, an energy consumption and performance comparison between the novel drivetrain, a conventional single-speed electric drivetrain and a double-speed electric drivetrain is discussed in detail for two case study vehicles.

A novel clutchless multiple-speed transmission for electric axles

The electric vehicle is becoming increasingly prevalent as a viable option to replace hydrocarbon fuelled vehicles, and as such the development of high efficiency fully electric drivetrains is a particularly relevant research topic. The drivetrain topology is one of the main focuses of research on fully electric drivetrains, because of the variety of available options. For example, the adoption of multiple-speed mechanical transmissions can improve both the performance and energy consumption when compared to a single-speed transmission. A four-speed, dual motor drivetrain design is presented in this article which works on the principle of two double-speed transmissions, each driven by a separate motor linked through a sole secondary shaft. This drivetrain architecture provides increased flexibility of the electric motor operating points, theoretically being beneficial to the overall efficiency of the system for any driving condition. This paper presents the design of the transmission, its governing equations and the method adopted to optimize the state selection map and electric motor torque distribution. A backward-facing energy consumption model is used to compare the results of the four-speed transmission with those of single- and double-speed transmissions for four case study vehicles.

Energy consumption analysis of a novel four-speed dual motor drivetrain for electric vehicles

Copyright © 2015 SAE International.This paper discusses the torque-fill capability of a novel hybrid electric drivetrain for a high-performance passenger car, originally equipped with a dual-clutch transmission system, driven by an internal combustion engine. The paper presents the simulation models of the two drivetrains, including examples of experimental validation during upshifts. An important functionality of the electric motor drive within the novel drivetrain is to provide torque-fill during gearshifts when the vehicle is engine-driven. A gearshift performance indicator is introduced in the paper, and the two drivetrain layouts are assessed in terms of gearshift quality performance for a range of maneuvers.

A Parallel Hybrid Electric Drivetrain Layout with Torque-Fill Capability

Because of the introduction of progressively more restrictive regulations that aim to reduce fuel consumption and CO2 emissions, the automotive industry is focusing its efforts on environmentally friendly passenger cars. In particular, different electrification roadmaps are pursued by the individual car makers, and electrified drivetrain layouts are progressively introduced into the market. This process involves all vehicle segments, including high performance passenger cars. In this context, this study presents a novel hybridized automated manual transmission (HAMT) for cars with high power characteristics. The HAMT includes six gear ratios associated with the internal combustion engine, and two gear ratios associated with an electric motor. The energy efficiency of the HAMT is measured on a drivetrain test rig, and compared with that of an equivalent dual clutch transmission (DCT). Simulation results based on the experimentally measured efficiency maps show the significant energy consumption reduction of the HAMT in its internal combustion engine mode, with respect to the DCT.

A novel hybridized automated manual transmission for high performance cars

Because of the introduction of progressively more
restrictive regulations that aim to reduce fuel consumption and
CO2 emissions, the automotive industry is focusing its efforts on
environmentally friendly passenger cars. In particular, different
electrification roadmaps are pursued by the individual car
makers, and electrified drivetrain layouts are progressively
introduced into the market. This process involves all vehicle
segments, including high performance passenger cars. In this
context, this study presents a novel hybridized automated manual
transmission (HAMT) for cars with high power characteristics.
The HAMT includes six gear ratios associated with the internal
combustion engine, and two gear ratios associated with an
electric motor. The energy efficiency of the HAMT is measured
on a drivetrain test rig, and compared with that of an equivalent
dual clutch transmission (DCT). Simulation results based on the
experimentally measured efficiency maps show the significant
energy consumption reduction of the HAMT in its internal
combustion engine mode, with respect to the DCT.

M. Fracchia

Papers

A novel clutchless multiple-speed transmission for electric axles

Energy consumption analysis of a novel four-speed dual motor drivetrain for electric vehicles

A Parallel Hybrid Electric Drivetrain Layout with Torque-Fill Capability

A novel hybridized automated manual transmission for high performance cars

A Novel Hybridized Automated ManualTransmission for High Performance Cars