Identification of Gear Shift Quality as a Key Attribute in Commercial Vehicle Development 2017-01-7011

Indian automotive market has grown extremely competitive in the recent past. In order to meet the ever growing expectations of the customers, automobile manufacturers are compelled to offer their products under superior quality with supreme comfort. Customers wish of high levels of tactile comfort in the cabin compartment and effortless operation of peripherals will result in negligible fatigue and a pleasant drive, needs to be duly fulfilled. One has to focus more on Gear shift lever and Steering wheel, which are being the most sensitive tactile points in an automobile. The gear shift lever knob is frequently used and significantly influences the perception of the shift comfort for a driver during actual vehicle application. The relevance of the shift comfort can be better understood in the daily life during heavy traffic conditions where the driver is required to perform frequent gear shifting operations which affect the driver comfort due to poor gear shift feel and high shift effort.

In past, objective assessment of gear shift quality used to be evaluated by a gear force sensor. Time based assessment was possible with this technique but not the identification of key parameters such as synchronization point, synchronization time, etc. with respect to GSL (Gear Shift Lever) travel. Information of key parameters will be helpful to explore the functioning of critical components inside the gearbox which have a strong effect on gear shift performance. Moreover, to broaden the scope of gear shift quality assessment requires capturing of these additional key parameters.

The scope of this paper is to provide a methodology for assessment of gear shift quality and explain how, the subjectivity of human perception with respect to gear shift comfort and feel can be correlated with key engineering parameters, derived through objective testing methods. The proposed test methodology not only captures the comfort level at gear shift lever, but also provides actual reactions at gearbox for further analysis, to make the development process more efficient.