Prospects for using the Bayes algorithm for assessing the technical condition of internal combustion engines

19th International Scientific Conference Engineering for Rural Development Proceedings

Akhmetzyanov

Arslanov

et al. 2020

Currently, methods of direct measurement of design parameters of technical condition are used to determine the remaining life of the engine. This requires complete or partial disassembly of the engine, which implies its decommissioning and subsequent placement on repair sites. The main argument in favor of such methods is the reliability of the results obtained, although this increases the labor intensity and cost of this process. The article proposes a method for non-selective evaluation of the residual life of the engine by the transient functions of its systems. The estimated parameters are the transient functions for fuel consumption, air consumption, and crankshaft speed. Quantitative indicators for transient functions are the intensity of changes in the selected parameters when the load is applied. Depending on the technical condition of the internal combustion engine, they have a high, medium and low level. To make a final decision about the technical condition of the engine, the Bayes algorithm on conditional probabilities is used. In case of an unfavorable combination of factors, this algorithm allows to assess the need for work to restore the engine resource with a certain probability. To improve the adequacy of the results obtained, it is necessary to use statistical data that reflect the relationship between the design parameters of the technical condition and the engine running time. The dependence of the selected diagnostic parameters on the technical condition of the engine is reflected in regression equations. Increasing the sample size of available data increases the accuracy of the diagnosis.

Section: Discussion Of Resultsmentioning

confidence: 99%

Method for determining remaining life of engine by dynamic characteristics

19th International Scientific Conference Engineering for Rural Development Proceedings

Akhmetzyanov

Arslanov

et al. 2020

“…Consider a method that uses the characteristics of an array of random values of time to failure, taking into account the unit cost of technical operation [12]. Two strategies are selected to maintain the vehicle in good technical condition: maintenance and repair.…”

Section: Status Of the Issuementioning

confidence: 99%

Methodology for determining standards of technical operation of vehicles taking into account their technical condition

20th International Scientific Conference Engineering for Rural Development Proceedings

Akhmetzyanov

Arslanov

et al. 2021

One of the important standards of technical operation of motor vehicles is the frequency of their maintenance. The correct definition of it directly affects the amount of specific operating costs and is one of the most important tasks of engineering and technical workers. At the same time, their reduced values, although they lead to an increase in the reliability of vehicles, but they increase the frequency of downtime and the cost of operation, as well as increase the share of unused resources of serviced systems and mechanisms. In this paper, we consider an economic-probabilistic method for determining the frequency of maintenance. There are two tactics for implementing this method: by operating time and by technical condition. For all its simplicity, the method of determining the operating time has a number of disadvantages, namely, it does not take into account the technical condition of the serviced mechanisms and units at the current moment. This increases the complexity of performing maintenance operations, and their cost increases accordingly. The method of determining the frequency of maintenance by condition is considered. In this case, all work on the maintenance of mechanisms and aggregates of vehicles is divided into diagnostic and executive components. At the first stage, their technical condition and resource are determined until the next scheduled maintenance. If this resource is not enough to run before this event, then a decision is made to perform the executive part of the work. With a larger resource, the executive part is postponed until the next scheduled maintenance. The determination of the frequency of maintenance is based on the results of comparing the specific operating costs for routine repairs with the weighted average costs for maintenance and routine repairs.

“…For the diagnosis of ICE malfunctions, a method based on the application of the Bayes algorithm is proposed, with the selected diagnostic parameters, the basics of which are proposed in the works [22][23][24][25]. In them, the internal combustion engine is considered as a dynamic system with stationary and deterministic characteristics, which allows to use identifying methods of dynamic systems.…”

Section: Offered Solutionmentioning

confidence: 99%

Method of non-disassembly diagnostics of automotive engines based on pulse functions of their systems

20th International Scientific Conference Engineering for Rural Development Proceedings

Matyashin

Martyshev

et al. 2021

The necessity to determine the technical condition of automotive internal combustion engines arises when their power, economic and environmental indicators deteriorate, as well as before performing the next major repair. Currently, disassembly and non-disassembly methods are used for this purpose. Disassembly methods, although they are the most reliable, are more labor-intensive and require the removal of the engine from the car, the availability of space and equipment for its disassembly. And non-disassembly methods have a low labor intensity, they practically do not require removal of the engine, while providing different reliability of the diagnosis depending on the method used. A method of non-disassembly diagnostics of automotive engines based on the pulse functions of their systems is proposed. As diagnostic parameters here are offered the pulse function of changes in the fuel and air supply of the engine at known values of compression in the cylinders. At the same time, the experience of operating automotive engines shows that the pulse function is a function of the current technical condition of the engine. By using the generalized Bayes formula for determining conditional probabilities, it is possible to determine the probability of failure of engine systems and the current technical condition. The undoubted advantage of the proposed method is its trainability, i.e. with an increase in the statistical data of the diagnosed engines, the reliability of the established diagnosis increases. The offered method will be useful for engineers and technicians involved in the maintenance of internal combustion engines for practical implementation.