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The continuously variable transmission (CVT) differs from the traditional automatic transmission (AT) in that it introduces an additional degree of freedom - the transmission ratio derivative (TRD) - into the control system. Based on the derived equation expressing dynamics of a car with CVT, the author analysed the influence of the TRD on the drive properties. The theoretical results were verified with the use of the Road Load Simulator (RLS).

The paper presents the properties of a prototype universal portable device for the determination of parameters of road vehicle driveability. The objective of this device is to enable the determination of driveability parameters in road vehicles. In this solution driveability parameters are determined only on the basis of acquired longitudinal acceleration during particularly designed road tests. The acceleration is measured with the use of accelerometer installed in the car body. During execution of the project numerous problems associated with the method of vehicle acceleration have been solved. Sources of errors in measurement method were determined. Methods and algorithms of road test time disturbances reduction were indicated. As a result accuracy of driveability parameter increased beside the repeatability of test results. The interpretation of the determined parameters is discussed in relation of road test course.

This paper presents the results of research, whose aim was to design and build a prototype device for the estimation of traction parameters of a car, including power output from engine. The estimation of the power of the powertrain system follows on the basis of measurements of the car's longitudinal acceleration in a special road test in actual driving conditions. The measurement of the longitudinal acceleration brings a number of problems which were solved due to the application of the new measurement method. The factors affecting deficiency of the precision of measurements and the methods applicable for its reduction were developed. As a result, it was possible to obtain a measurement method with reduced uncertainty and increased repeatability in terms of results. In addition, an interpretation of the results of the test is presented in reference to the power of the powertrain and engine.