Papers by Author: Paweł Lindstedt

Abstract: While an aircraft engine is being used, its wear takes place. Its gain coefficients decrease and at the same time its time constants increase (engine becomes „weak“ and „slow“). Therefore, the rigorously definite adjustment of engine according to the principles of automatics and manufacturer recommendations is carried out periodically during the ground service of engine. The practice shows that during ground tests an engine works in „easy“ surrounding, however, during flight an engine works in „difficult“ surrounding. After good adjustment of an engine from changing the set value w during the ground service, this engine may not meet requirements of the work quality by variable disturbances z during the flight. Therefore arises a problem of the synthesis of quantification of the control possibility of engine which will result in connecting the operation status of engine (automatics) with the maintenance status of engine (diagnostic). The measure of this relationship can be named „the control potential“ of the engine. The control potential can be determined from the equation of state: , where: y – operational signal of engine, u – diagnostic signal of engine, b – coefficient of intensity of influence of the maintenance status of engine on its control possibilities, a – control potential of engine,  - operation time (Bergson’s time). The parameter „a“ calculated with help of static and dynamic identification methods will permit to estimate the functional value of engine during its ground tests.

Abstract: A focus of the paper is concerned with the issue that optimal actions of regulation, diagnostics and reliability tests of technical objects are required from the maintenance staff involved in their use and servicing, and on the other hand, that they are performed independently and autonomously in the current maintenance practice instead of being accomplished in a strictly coordinated and complex way. It was noticed that only one and common information on the object exists and provides a solid basis for coordination of the regulation, diagnostics and reliability tests. This information can be applied many times for solving various problems no matter if they concern regulation, diagnostics or reliability. Next, this paper presents an original approach of conversion of the considered information into explicit time-and-space determined “number of threshold value overshoots” of signals related to the object and its environment as well as theoretical foundations (based on various configurations of the state equation) for conversion of the considered piece of information, expressed by the aforementioned “numbers”, into the parameters of the object ability condition (i.e., its technical condition, adjustment and reliability). The theses of the presented complex method for the assessment of technical object ability were subjected to long-term verification with positive result in the study of the Allison 250 engine bearing system.