Method of in-depth diagnostics of the main brake cylinder of a motor vehicle

The use of new methods for element-by-element diagnostics of the brake system increases the probability of detecting malfunctions, helps to identify faulty elements in the nodes of the brake system in advance, which helps to reduce accidents on the roads of the country. The development of a method for in-depth diagnosis of the master brake cylinder is an urgent task. Earlier, as part of the development of a new method for diagnosing the main brake cylinder of a hydraulic brake system, a set of diagnostic parameters was determined by the dynamic parameters of the resistance force to pressing the brake pedal. The need to introduce the method for practical use at road transport enterprises set the authors the task of determining the maximum permissible values of diagnostic parameters based on the comparison results, with which a conclusion will be made about the technical condition of the object with subsequent diagnosis. The aim of the work is to determine the maximum allowable values of diagnostic parameters, and to develop an algorithm for making a diagnosis. The maximum permissible values of the diagnostic parameters of the main brake cylinder were determined on the basis of a statistical method. The main provisions of the method are that a one-time sample of N values of the diagnostic parameter was considered for representatives of the set of diagnostic objects (both serviceable and faulty). At the same time, it was assumed that the values corresponding to the serviceable state would obey a different pattern than the values corresponding to the faulty one. Having singled out the distribution function f(S) of the parameter values for the healthy state of the object from the total population, the range of acceptable values of the diagnostic parameter in operation can be limited by some limiting dispersion relative to the nominal (reference) value of the parameter. For the braking system affecting traffic safety, the restriction was applied with 85% probability. The values were found for the entire range of diagnostic parameters. In the course of the study, the maximum permissible values of diagnostic parameters were determined. A diagnostic matrix of the main brake cylinder has been built. An algorithm for making a diagnosis has been developed. The scientific novelty lies in the difference in their implementation in the range of service braking, which makes it possible to maximize the informative possibility of each of the diagnostic parameters.