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FOV splicing optical remote sensing instruments have a strict requirement for the focal length consistency of the lens. In conventional optical-mechanical structure design, each optical element is equally distributed with high accuracy and everyone must have a high machining and assembly accuracy. For optical remote sensors with a large number of optical elements, this design brings great difficulties to lens manufacture and alignment.

Taking the relay lens in an optical remote sensing instrument with the field of view splicing as an example, errors of the system are redistributed to optical elements. Two optical elements, which have the greatest influence on modulation transfer function (MTF) of the system are mounted with high accuracy centering and the other elements are fixed by gland ring with common machining accuracy. The reduction ratio consistency difference among lenses is compensated by adjusting the optical spacing between the two elements.

Based on optical system simulation analysis, the optimized structure can compensate for the difference of reduction ratio among lens by grinding the washer thickness in the range of ±0.37 mm. The test data for the image quality of the lens show that the MTF value declined 0.043 within ±0.4 mm of space change between two barrels. The results indicate that the reduction ratio can be corrected by adjusting the washer thickness and the image quality will not obviously decline.

This paper confirms that this work is original and has not been published elsewhere nor is it currently under consideration for publication elsewhere. In this paper, the optimum structural design of the reduction relay lens for the field of view stitching applications is reported. The method of adjusting washer thickness is applied to compensate for the reduction ratio consistency difference of lenses. The optimized structure also greatly reduces the difficulty of lenses manufacture, alignment and improves the efficiency of assembly.

An electrorheological (ER) fluid comprises dielectric particles suspended in an insulating viscous medium. ER lubricants are considered smart lubricants. They have been applied in hydraulic valves, power transmission devices and damping systems. The purpose of this study is to investigate the performance of hydrostatic thrust bearing operating with ER lubricant.

Reynold’s equation was used to model the flow of the ER lubricant in the bearing. The continuous Bingham model was used to express the viscosity of the ER lubricant as a function of yielding stress, applied electric field and shear strain rate. The Reynolds equation is solved using the finite element method (weighted residual approach) to compute the film pressure as a primary variable and the lubricant flow rate, load-carrying capacity, stiffness and damping parameters as associated performance indices.

The effects of the pocket shape, compensating elements and ER lubricant on the bearing performance were investigated. The application of ER lubricant significantly enhanced the load-carrying capacity (48.2%), stiffness (49.8%) and damping (4.95%) of the bearings. Circular and triangular pocket bearings with constant-flow valves have been reported to provide better steady-state and rotor-dynamic performances, respectively.

This study presents the effect of an ER lubricant on the rotor-dynamic performance of hydrostatic thrust bearings with different pocket shapes.

Hole‐entry hybrid journal bearings are widely used in many applications owing to their favourable characteristics. Ever increasing technological developments demand much improved performance from these class of bearings operating under the most stringent, exact and precise conditions. Therefore, it becomes imperative that the hole‐entry journal bearings be designed on the basis of more accurately predicted bearing characteristics data. The purpose of this paper is to describe a theoretical study to demonstrate the combined influence of the effect of pocket size at the outlet of supply holes and the journal misalignment on the performance of an orifice compensated hole‐entry hybrid journal bearing system.

Finite element method is used to solve the Reynolds equation governing the flow of an incompressible lubricant in the clearance space between the journal and bearing together with equation of flow through an orifice. The journal misalignment has been accounted for by defining a pair of misalignment parameters sigma and delta. The effect of pocket size at the outlet of supply holes has been accounted by defining a non‐dimensional parameter which is function of diameter of pocket and journal diameter.

The results presented in this paper indicate that the effect of journal misalignment is, in general, to cause a reduction in bearing dynamic characteristics parameters whereas the effect of pocket size is to slightly compensate this loss. Performance of a two lobe four recessed journal bearing, a proper selection of bearing offset factor along with type of restrictor (capillary or orifice) is essential.

This paper presents valuable data relating to hole‐entry hybrid journal bearings useful for bearing designers.

Differential pressure is an important technological parameter, one urgent task of which is control and measurement. To date, the lion’s share of research in this area has focused on the development and improvement of differential pressure sensors. The purpose of this paper is to develop a smart differential pressure sensor with improved operational and metrological characteristics.

The operating principle of the developed pressure sensor is based on the capacitive measurement principle. The measuring unit of the developed pressure sensor is based on a differential capacitive sensitive element. Programmable system-on-chip (PSoC) technology has been used to develop the electronics unit.

The use of a differential capacitive sensitive element allows the unit to compensate for the influence of interference (for example, temperature) on the measurement result. With the use of PSoC technology, it is also possible to increase the noise immunity of the developed smart differential pressure sensor and provide an unparalleled combination of flexibility and integration of analog and digital functionality.

The use of PSoC technology in the developed smart differential pressure sensor has many indisputable advantages, as the size of the entire circuit can be minimized. As a result, the circuit has improved noise immunity. Accordingly, the procedure for debugging and changing the software of the electronics unit is simplified. These features make development and manufacturing cost effective.

Hybrid journal bearing have long been used in machines requiring large load and high speed capacity operating under wide range of temperatures. Different compensating devices are used in for efficient operation of bearings. This paper aims to help in selection of optimum compensating device by evaluating the comparative performance of constant flow valve, capillary compensated and slot entry hybrid journal bearing under the combined influence of thermal effects and micropolar nature of lubricant.

The variation in micropolar parameters and viscosity change due to temperature increase of lubricant are considered in present study. Finite element method is used for combined iterative solution of micropolar Reynolds, energy and conduction equations. Micropolar lubricant is assumed to be governed by two parameters, coupling number and characteristic length. The results in the study are presented for symmetric and asymmetric configurations of hole entry and slot entry non-recessed hybrid journal bearings

The results indicate that constant flow valve compensated hole entry hybrid journal bearing is the highest performing bearing for the given range of micropolar parameters of lubricant in terms of maximum fluid pressure and dynamic coefficients.

The performance variations of various configurations of hybrid journal bearing are presented in a single paper. The reader can get overview of combined effects of micropolar parameters and viscosity decrease due to temperature increase of the lubricant.

Flexible automation robotic systems and off‐line programming methods have recently received much attention. Studies the problem of robot auto‐marking and auto‐cutting of shipbuilding panels, using an integrated computer aided design/manufacturing (CAD/CAM) system based on computer technology and off‐line programming of the robot. The following three points are focused on in this paper: marking and cutting information of the panel’s CAD model; measurement of the panel’s deformation and its compensation algorithm; robot auto‐making and auto‐cutting of the panel using the CAM system. Robot auto‐marking and auto‐cutting of shipbuilding panels solves the difficulty associated with panel marking and cutting by hand. Furthermore this system possesses high processing precision and automatically compensates for the deformation of the panel. Our experiments prove the feasibility and efficiency of this system at the end of this paper.

The design of temperature‐compensated quartz crystal oscillators (TCXOs) in thick film hybrid technology is described. TCXOs controlled by varicap diodes are usually realised with discrete NTC thermistors and resistors. Data obtained by precision measurements of voltages on varicap diodes for the same oscillator frequencies over the operating temperature range are used for calculating values of the NTC thermistors and resistors. In most cases these values cannot be found in the Renard scale, with the result that manipulation or ‘juggling’ of values is necessary. The realisation of temperature‐compensating circuits in thick film technology has certain advantages, such as miniaturisation, better characteristics at high frequencies and in particular the possibility to trim thick film resistors and NTC thermistors to values calculated for each oscillator. The method of realisation of TCXOs in thick film hybrid technology was developed and verified on prototypes. The compensation curves were obtained by measuring compensation voltages for each oscillator over the operating temperature range from — 20°C to 70°C. From these data the values of resistors and NTC thermistors were calculated. A computer program was used to minimise frequency instability error as a function of six parameters (resistance). The frequency stability (Δf/f) of TCXOs obtained was better than ±2 ppm.

In the measurement of liquid density and viscosity, the change of resonance parameters due to the parasitic parallel capacitance of resonator affects the measurement accuracy. To improve the accuracy, a method was proposed to compensate the parasitic parallel capacitance of resonator by adding an electrode.

The new electrode (compensation electrode) was added into resonant sensor to make compensation capacitance. The closer the compensation capacitance was to the parasitic parallel capacitance, the better compensation was. The structural parameters of resonant sensor with the compensation electrode were determined by the simulation and experiment.

The effect of this method was examined by the experiment. The relative errors of density and viscosity were less than 0.15, 0.5 % and standard deviations were less than 0.0004 g/cm³ and 0.005 mPas, respectively.

The experimental results show that this method is valuable for the parasitic parallel capacitance compensation of immersed resonant sensor.

This paper has not been published in other journals.

The purpose of this paper is to develop a novel type of full‐size flight control iron bird based on a passive electronic hydraulic servo loading system.

On the basis of mathematical modeling of passive loading system math model, the detailed design process of the flight control iron bird is presented. Subsequently, the system digital simulation and physical verification are also given.

Experimental results show that the proposed approach can reduce the redundant forces and improve the system dynamic and force‐tracking accuracy.

This newly‐developed flight control iron bird system has been successfully applied in the flight control system design of some fighters.

The proposed approach for flight control iron bird is new and significant for the design of fighter flight control systems.