Distributed measurement often relies on sensor networks. In this paper, we present the construction of low-coherence fiber-optic Fabry–Pérot sensors connected into a quasi-distributed network. We discuss the mechanism of spectrum modulation in this type of sensor and the constraints of assembly of such sensors in the network. Particular attention was paid to separate the signals from individual sensors which can be achieved by cavity length-based addressing. We designed and built a laboratory model of a temperature sensors network. The employed sensors are low-coherence Fabry–Pérot interferometric sensors in a fiberoptics configuration. The extrinsic sensor cavity utilizes the thermal expansion of ceramics, and the sensors are addressed by the different lengths of the cavities. The obtained test results showthat the signal components from each sensor can be successfully separated, and the number of sensors could be expanded depending on the FWHM of the light source.

The paper presents an analysis of determining the load of a model tunnel lining in a noncohesive soil medium at two different heights of soil backfill above the structure. A series of simulations were performed with the flexible and rigid tunnel lining. The analysis was performed by conducting simulations with the use of an author’s program based on the discrete element method. The model previously calibrated on the basis of laboratory tests was used. The loads acting on the structure, the distribution of stresses in the surrounding soil medium and the displacements of this medium in the vicinity of the structure were determined and compared. The effect of soil weight and technological load applied from the surface was taken into account. The values of the numerically obtained loads of the tunnel lining were compared with those calculated according to the classic Hewett’s method.
It has been proven that in both cases the degree of cooperation between the structure and soil is significantly related to the rigidity of the structure, hence the loads determined may differ significantly from the results obtained according to classical methods. It was shown that discrete modelling allows to reflect differences in the behaviour of the soil medium resulting from different heights of soil backfill. Smaller horizontal pressure was obtained in the side zones of an excavation at a higher backfill. In addition, significantly greater intensity of vertical soil displacements over the lining were observed with a lower backfill height.

This paper deals with the design of an interval state estimator for linear time-varying (LTV) discrete-time systems subject to component faults and uncertainties. These component faults and uncertainties are assumed to be unknown but bounded without giving any other information, whose effect can be approximated using these bounds. In the first part of this work, an interval state estimator for such systems is designed to deal with these component faults and uncertainties. The result is then extended to find an interval state estimator for a non-cooperative LTVdiscrete-time system subject to component faults and uncertainties by similarity transformation of coordinates. The proposed interval state estimator guaranteed bounds on the observed states that are consistent with the system states. The observer convergence is also ensured. The designed method is simple and easy to be implemented. Two numerical examples are given to show the effectiveness of the proposed method.

The paper presents the results of research work on the development of a rapidprototyping test stand for testing: servo control algorithms, trajectory generation, algorithms for increasing overall quality of the feed-drive modules within two axis (X-Y) table of the milling machine. Open architecture interface of the prepared control system lets the potential user test functionality of integration of diagnostic tools within the motion controller - directly, without taking into account communication with top-level CNC system.