Automotive Innovation https://doi.org/10.1007/s42154-018-0031-y Progress in Automotive Transmission Technology Xiangyang Xu1,2·Peng Dong1,2·Yanfang Liu1,2·Hui Zhang1,2 Received: 21 June 2018 / Accepted: 31 July 2018 © The Author(s) 2018 Abstract Much progress has been made in the development of automotive transmissions over the past 20 years, e.g., an increased speed number, expanded ratio spread and improved efficiency and shift quality. Automotive transmissions are moving toward electrification in response to stringent legislation on emissions and the pressing demand for better fuel economy. This paper reviews progress in automotive transmission technology. Assisted by computer-aided programs, new transmission schemes are constantly being developed. We therefore first introduce the synthesis of the transmission scheme and parameter optimization. We then discuss the progress in the transmission technology of a conventional internal combustion engine vehicle in terms of new layouts; improved efficiency; noise, vibration and harshness technology; and the shifting strategy and control technology. As the major development trend, transmission electrification is subsequently discussed; this discussion includes the configuration design, energy management strategy, hybrid mode shifting control, single-speed and multi-speed electric vehicle transmission and distributed electric drive. Finally, a summary and outlook are presented for conventional automotive transmissions, hybrid transmissions and electric vehicle transmissions. Keywords Automotive transmission ·Hybrid transmission ·Electric vehicle transmission ·Distributed electric drive · Scheme synthesis ·Electrification Abbreviations AMT Automated manual transmission A T Automatic transmission CD Charge depleting CS Charge sustaining CVT Continuously variable transmission DCT Dual-clutch transmission DHT Dedicated hybrid transmission DOF Degree of freedom ECVT Electric continuously variable transmission EM Electric motor EOP Electric oil pump EV Electric vehicle FWD Front-wheel driving HEV Hybrid electric vehicle B Peng Dong peng.dong@buaa.edu.cn 1School of Transportation and Science Engineering, Beihang University, Beijing 100191, China 2Beijing Key Laboratory for High-efficient Power Transmission and System Control of New Energy Resource V ehicle, Beihang University, Beijing 100191, ChinaICE Internal combustion engine ILC Iterative learning controller MT Manual transmission MOP Mechanical oil pump NMPC Nonlinear model predictive controller NVH Noise, vibration and harshness OWC One-way clutch PGP Parallel-axis gear pair PGS Planetary gear set PHEV Plug-in hybrid electric vehicle PID Proportional-integral-derivative R&D Research and development RGS Ravigneaux gear set SE Shifting element THS Toyota Hybrid System 1 Introduction With pressing demands to reduce emissions and improve fuel economy, automotive transmissions have evolved over the past 20 years while rapidly progressing toward elec- trification. Conventional automotive transmissions for the 123X. Xu et al. internal combustion engine (ICE) are generally classified into manual transmission (MT), automated manual transmission(AMT), automatic transmission (A T), dual-clutch transmis- sion (DCT) and continuously variable transmission (CVT). This review focuses on the progress of A T, DCT and CVTbecause they largely account for the development of trans-mission technology in the past 20 years and have gradually replaced MT and AMT in passenger cars. Automotive transmissions are undergoing electrification to meet stringent legislations pushing for CO 2reduction. As electromechanical coupling systems, transmissions in hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles(PHEVs) are important in terms of achieving different driving modes, such as series, parallel and power-split modes. With the integration of the electric motor (EM) into conventionalA Ts, DCTs and CVTs are examples of transmission electrifi-cation and are normal