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

© 2016 Elsevier Ltd The purpose of this paper is to demonstrate the application of torque based powertrain control for multi-speed power shifting capable electric vehicles. To do so simulation and experimental studies of the shift transient behaviour of dual clutch transmission equipped electric vehicle powertrains is undertaken. To that end a series of power-on and power-off shift control strategies are then developed for both up and down gear shifts, taking note of the friction load requirements to maintain positive driving load for power-on shifting. A mathematical model of an electric vehicle powertrain is developed including a DC equivalent circuit model for the electric machine and multi-body dynamic model of the powertrain system is then developed and integrated with a hydraulic clutch control system model. Integral control of the powertrain is then performed through simulations on the develop powertrain system model for each of the four shift cases. These simulation results are then replicated on a full scale powertrain test rig. To evaluate the performance of results shift duration and vehicle jerk are used as metrics to demonstrate that the presented strategies are effective for shift control in electric vehicles. Qualitative comparison of both theoretical and experimental results demonstrates reasonable agreement between simulated and experimental outcomes

A novel shift control concept for multi-speed electric vehicles

© 2018 Elsevier Ltd This paper proposes a novel synchronizer ‘Harpoon-Shift’ aiming at improving the comfort and efficiency of gearbox, meanwhile, simplifying the shifting control strategy for multi-speed electric vehicles. It will overcome one of the biggest shortcomings of traditional synchronizer system with frictional cone clutch. Experiment is established to investigate the torque and speed responses during the engagement of gears pairs. Then, based on previous testing results, the relationship of the peak torque and minimum speed difference to implement gear shifting with various spring coefficients is investigated. In addition, a mathematical model of the Harpoon-Shift system is developed to simulate the engagement process. The simulation results of system transient responses are validated against the data measured on testing rig. The model is then improved to study the impact of the rotating inertia, speed and speed difference on the torsional vibration and required time of engagement. Both of the simulation and experimental results show the significant improvement of proposed synchronizer to conventional cone clutch synchronizer

Design, Control and Validation of Two-Speed Clutch-less Automatic Transmission for Electric Vehicle

Two-speed or multiple-speed automatic transmissions can obviously improve the overall manipulating performance in terms of shifting quality and energy efficiency when equipped in electric vehicles (EVs). This study details the design of a two-speed clutch-less automatic transmission (2AT) for EVs and the motor controlled shifting mechanism. Firstly, a novel two-speed clutch automatic transmission is devised with a motor-controlled shifting mechanism, which enables the shift motions and the speed control of the driving motor for synchronization during shifts. Secondly, a coordinated control strategy of the driving motor and controlling motor for shifting is detailed during different shifting processes to achieve fast and smooth shifting. The torque trajectory optimization during synchronizing process is attained by applying the Pontryagin's minimum principle. The simulation and experimental results verify the shifting mechanism design and the shift control algorithm in terms of shift response and smoothness for the designed 2AT

Hybrid Electric Powertrain Design and Control with Planetary Gear Sets for Performance and Fuel Economy

Planetary gear sets (PGs) play a key role in hybrid electric vehicle (HEV) design by enabling a variety of unique architectures using a limited number of powertrain components. Leveraging the capability of this mechanical device, this study introduces an automated design process for PG-based HEV systems focusing on both fuel economy and performance, while also deriving the necessary analysis and synthesis tools. First, the design process generates all possible modes in an HEV design with a given set of powertrain components. The data structure and the derivation method of speed and torque relationships of each mode enable an exhaustive search of the large design space that grew with all the component topology and PG gear ratio combinations. Second, all powertrain types realizable with a given set of components are mathematically shown, and each feasible mode is classified under one of these powertrain types. Third, computationally efficient linear programming solvers suitable for vector operations are developed for each powertrain type to assess the forward- and backward-speed gradeability, long-hauling torque, and acceleration time of each mode for all PG gear ratio combinations. Fourth, the combination of modes that meets the performance requirements, along with the number and location of clutches that make these mode transitions possible, are identified. As a result, each potent mode combination, the clutches necessary for the mode transition, and the auxiliary modes established through all clutch state combinations constitute a design that meets the performance criteria. Last, the fuel economy improvement potential of each design is evaluated using an algorithm that approximates dynamic programming optimization. The results show that light-duty truck performance requirements can be met by many two-PG HEV designs without sacrificing fuel economy if the right analysis and synthesis techniques for exploring the entire design space are developed. In addition to the design process, the feasibility of mode transitions and the effect of mode transitions on the fuel economy simulation results are investigated. For this purpose, the dynamics of mode transition is analyzed, and control algorithms achieving the transitions without interrupting the desired vehicle torque are developed. Then, these analysis and synthesis techniques are automated so that they can be integrated into the fuel economy simulation algorithm. The simulation results reveal that some mode transitions have a negative effect on fuel economy and the assumption of mode transition feasibility at any operating point is not valid.PHDElectrical Engineering: SystemsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/144111/1/oguzhada_1.pd

Future Transportation

Greenhouse gas (GHG) emissions associated with transportation activities account for approximately 20 percent of all carbon dioxide (co2) emissions globally, making the transportation sector a major contributor to the current global warming. This book focuses on the latest advances in technologies aiming at the sustainable future transportation of people and goods. A reduction in burning fossil fuel and technological transitions are the main approaches toward sustainable future transportation. Particular attention is given to automobile technological transitions, bike sharing systems, supply chain digitalization, and transport performance monitoring and optimization, among others

Federal Register

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii