Abstract: |
This dissertation describes the implementation and investigation of a road vehicles testing system, which architecture is based on the most widespread micro controller 8751. A new definition of a system for road vehicles performance testing is given and following this definition the existing methods and tools for testing are thoroughly analysed.
Mechanics-mathematical models of the processes of acceleration and braking are crated. A new graphical model of the process of acceleration with changing gears is created. These models are used for frequency analysis of the road vehicles performance and sampling rate. It is demonstrated that instead of a constant sampling rate an adaptive rate based on the distance must be used.
In the system the functional dependence a=f(t) is obtained after two successive numerical differentiation of the functional dependence S=f(t). As the conditions during the experiment vary it is difficult to determine the right methods for filtering and numerical differentiation. In this dissertation a new procedure, which uses imitation models of acceleration and braking to determine the filtering and numerical differentiation methods, is suggested.
Graphoanalytical models of the microprocessor systems and the computer software are accomplished and a rational choice of their architecture is performed. A new tenzometric amplifier with improved metrological and ergonomic characteristics is developed. A functionally complete system is created and criteria for quality assessment are formulated. The system has been implemented in organisations, which teach students, and in factories concerned with design, production, maintenance and testing of road vehicles. The specialists think that the application of the system leads to a considerable improvement of accuracy and reliability of testing. |
