The torque control of wind turbines in below-rated wind speeds involves a trade-off between power capture and generator loads. This paper explores this fundamental trade-off in the presence of preview wind information. A continuous-time optimal control problem is formulated on a one-state nonlinear turbine model. The numerical solution of this problem gives the Pareto optimal relationship betwe...

A procedure to build up a dynamical model of the gearbox with spur involute mesh is being described. The main attention is paid to the design technology of the cylindrical bodies elastic contact models. To track geometry of contact implicit equations of algebraic/transcendental or differential-algebraic type are being used. At the same time dynamical models of the bodies involved, gearwheels an...

This paper introduces a wavelet based, nonparametric statistical method for the detection of characteristic signals embedded in noise-polluted vibrational response signals. A case study is described in which this technique is applied to the task of identi~ying localised defects on the raceways of the roller bearings inside an automotive gearbox, assuming that during operation a transient impuls...

In this paper, an approach based on Wavelet packet transport, principal component analysis is presented for detection of fault diagnosis of gearbox of MF285 tractor. The vibration signal acquired from the experimental set up has been used to diagnose the condition. An acceleration sensor is used to pick up the vibrational signals by experimental set up. After acquisition vibrations data, proces...

Nowadays, shovels play an important role in production of open pit mines and their failures result in significant production loss and considerable increase in maintenance costs. Therefore, reliability and risk analysis can help to improve production, productivity and reduce production costs. In this study, reliability of electric cable shovel of Chadormalu iron ore mine in Iran was investigated...

Gearbox maintenance is not an easy task and conventional diagnostic techniques do not always provide suitable indication about failures. In this paper, tooth crack failures have been experimentally investigated. The mechanical system is composed of a two-stage gearbox with spur gears. Two depths of gear cracks are treated. Cyclostationnarity analysis of order 2 has been conducted to some experi...

A proof is given, which relies on the commutator algebra of the unitary Lie groups, that quantum gates operating on just two bits at a time are sufficient to construct a general quantum circuit. The best previous result had shown the universality of three-bit gates, by analogy to the universality of the Toffoli three-bit gate of classical reversible computing. Two-bit quantum gates may be imple...

This paper presents a two-stage integrated approach to assess the reliability of components for reuse in the second life cycle. Statistical data analysis, the first stage of the proposed method, determines the mean life of components by analysing the time-to-failure data for an electric motor and gearbox of a washing machine. A well-known reliability assessment method, Weibull analysis has been...