Abstract
<div class="section abstract"><div class="htmlview paragraph">This paper presents a feedback control strategy aimed to reduce noise and wear during gearshifts in conventional and hybrid Dual Clutch Transmissions (DCT and DCTH) and Automated Manual Transmissions (AMT). The control strategy is based on a new dog teeth position sensor developed by China Euro Vehicle Technology AB and existing speed sensors in the transmission. During gear shifting, noise is generated by impacts between the sleeve teeth and the idler gear dog teeth after speed synchronization. Besides noise, these impacts are also responsible for delaying the completion of shift and contribute to wear in the dog teeth, hence reducing the lifespan of the transmission. The presented control strategy controls speed synchronization such that the impact between sleeve and idler gear dog teeth, before the start of torque ramp up, is avoided. Since drag torque is an important factor in speed synchronization, this paper also contains an algorithm to identify friction torque coefficient in the transmission. The identification method ensures that the controller adapts to varying conditions without the need for offline calibration. The control strategy is developed for standard automatic gear shifting operations but minor adaptations in the algorithm also make it capable of handling gear shifts requested by the driver. The output signal of the control strategy is acceleration request on idler gear during speed synchronization. To make controller easier to implement and minimize shift time, the acceleration request only has two values, either maximum value or zero. The control strategy is designed in such a way that it can easily be integrated in the existing transmission control software. By applying the control strategy on a detailed simulation model, it is shown that the impacts during gear engagement are significantly reduced.</div></div>
Highlights
Throughout the last decades, reducing emissions has been the focus of the automotive industry
The introduction of electric motors (EM) for traction in the vehicles have significantly reduced the usage of combustion engines (ICE) so vehicles spend more time driving in zero emission mode
This paper has presented detailed design recipe for a modelbased feedback controller for synchronizer systems to guarantee minimum noise and wear and fast gear engagement during gear shifts
Summary
Throughout the last decades, reducing emissions has been the focus of the automotive industry. The introduction of stricter legislation during the recent years has made the hybrid powertrains more popular. The introduction of electric motors (EM) for traction in the vehicles have significantly reduced the usage of combustion engines (ICE) so vehicles spend more time driving in zero emission mode. ICE is one of the main sources of noise in the vehicle. When the usage of ICE is decreased other noise sources in the vehicle which were not deemed important in the past become more emphasized. This paper deals with noise generation during gear shifting. For gear shifting in hybrid vehicles DCT and AMT are used. DCT and AMT use conventional synchronization systems, operated by automated shifting actuators as shown in [1] and [2]. The high-level gear shifting process can be divided into following phases [1]
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