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Stemming from predictions made for transmission adoption and sub-system volumes up to 2020 for the EU market, a concept study and recommendations are presented for a 6-speed 200Nm powershift transmission covering the following: Specific new features for low cost and high efficiency applied to a DCT, Novel, direct acting electromagnetic linear actuators for modulation of clutches and shift rails, Mechanical multiplexing to allow control of both clutches and shift rails using two linear actuators only.

The paper reports upon the invention, development and critical assessment of key subsystems applied to electrically actuated AMTs and DCTs, and describes their simulation, design, rig testing and associated demonstration vehicles. Specially, these devices address the following: direct clutch and gear actuation using a moving magnet linear actuator; devices to reduce the actuation power for sustained control of wet or dry clutches targeting an average actuation energy over the NEDC cycle of < 30W electrical power; thermal management of a dry clutch using a heat transfer device to maintain facing materials below 220°C; requirement for a device to prevent roll-back on an incline and hence avoid significant clutch heating; in combination, increase the life of DCT dry clutch modules to 150,000 miles for small and medium cars.

This paper follows on from a previous publication [1] and describes the continued development of a generic Integrated Powertrain (IPT) model. Simulation tools have been used for many years in engine and vehicle development programmes, to predict fuel consumption and emissions over various drive cycles. The concept phase of these programmes typically considers the overall layout and sizing of the components, with the detailed control strategies developed later. Today, the increased integration of vehicle sub-systems requires a high degree of overall control early in the programme, firstly, to allow the sub-systems to function, and secondly, to apply a similar quality of system control to each hardware iteration. To address this issue, a control hierarchy has been applied comprising of a supervisor controller and multiple local controllers.

In Europe there is considerable growth in the application of automated manual transmissions (AMT) predominantly for reasons of cost and CO2 efficiency. It is believed that restricted functionality and the poor shift quality of this “first wave” of manual-based transmissions may hinder this trend being repeated in markets dominated by conventional automatic transmissions (ATs) such as the USA. This paper addresses two areas: Results and analysis of measured and subjective data from a comprehensive, independent survey of six AMT vehicles available in Europe. Techniques to predict subjective ratings of shift quality from physical variables. Data is presented from a wider survey of current production “robotised” manual transmissions sold in the European market. This study included vehicles from B, C, and D/E classes and the light truck sector.

A driver's preference for one of two different vehicle models that have the same measurable acceleration may be explained by complicated factors such as styling, NVH or ergonomics. If the vehicles have identical appearance but different levels of engine tune, discrimination would probably be due to the measurable difference in performance although other factors cannot be entirely discounted. If however, the assessment is made of vehicles with identical appearance and identical performance then any preference is attributable to an area of human assessment that has been termed subjective performance. This paper discusses the first step in a qualitative approach to the analysis of driver perception of vehicle performance and more specifically investigates subjective performance. The proposed model ascribes distinct components such as induced and perceived performance to the total subjective performance rating.