Abstract
Keywords: combustion engine, energetic efficiency, power transmission systems, inertia, control strategies
The most disadvantageous system of the automobile, because of its damaging influence on environment is powertrain. This notion means engine connection with powertrain, which is very important in respect of ecology and safety. In the matter of safety very important is ability to accelerating with rapid depressed accelerator pedal. This situation takes place during overtaking process, which is caused by driving force deficiency from engine and powertrain mechanical inertia. It has negative influence on overtaking process and also on driving comfort. This phenomenon described in works (Vroemen, 2001) , mainly come from accumulation of mechanical energy of powertrain. It leads to driving force drop as a result of energy accumulation in first phase of the overtaking process, and in the next phase leads to arising excessive driving force on wheels.
Numerous research centers in the world have undertaken examinations with an aim of solving this problem. However, a successful solution to this problem has to meet a number of prerequisites of technological and economic nature. The technological ones have to involve the uncomplicated construction while the economic ones are associated with the need for low cost of application of the solution put forward. The latter question is related to meeting numerous conditions and results from the effects of special testing as a result of specific operating conditions of power transmission system.
Using of electronic throttle control can restrict this torque drop phenomenon. Like show research (Mamala, 2002), related with optimization of throttle angle in intake manifold it may lead to reduction this driving force deficiency. From the diagrams it results, that the reduction of opening throttle speed results in the reduction of oscillations amplitudes of the power transmission system. It leads to an improvement of the history of driving force. It promotes the improvement of the comfort of driving a passenger car, reduces jerks while simultaneously does not lead to a considerable deterioration of longitudinal dynamics of a car (Deneuville, 1995).
Nevertheless, the limitation imposed to throttle opening do not compensate the originating shortage of driving force as a result of an increase in the rotational speed of the engine and power The solution to the problem of transitory shortage of driving force will promote the improvement of safety on the roads. It can also enable the establishment of novel algorithms for the control of power transmission system.