On the basis of the Barus experimental research, the viscosity of an incompressible lubricant grows exponentially with its pressure. Therefore, the squeeze film issues between parallel circular plates lubricated with a non‐Newtonian couple‐stress fluid are reexamined in the present study by considering the effects of viscosity‐pressure dependency. According to the results, the influences of viscosity‐pressure dependency raise the load capacity and lengthen the approaching time of the plates. Numerical results under different values of the viscosity parameter and the non‐Newtonian parameter are also provided in tables for engineering applications. Copyright © 2012 John Wiley & Sons, Ltd.

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On the basis of the Eringen's micro-continuum theory, this study is mainly concerned with the effects of non-Newtonian micropolar-fluid rheology on the squeeze-film characteristics between a sphere and a plate surface. To account for the micro-rotational effects and the micro-rotational inertia of the fluid elements arising from the lubricant blended with additives, the non-Newtonian Reynolds-type squeeze-film equation is derived using the continuity equation and the linear momentum equations coupled with the angular momentum equations. A closed-form solution for the film pressure, the load-carrying capacity and the time—height relationship is obtained for engineering applications. According to the results, the effects of non-Newtonian micropolar fluids provide an increase in the load capacity, and therefore lengthen the response time to prevent the contact of sphere with plate. Furthermore, the non-Newtonian effects on the squeeze-film characteristics are more emphasized under lower squeeze-film heights with larger coupling numbers and smaller interacting parameters. As the value of the coupling number tends to zero or the value of the interacting parameter approaches infinity, the presented derivation provides a close agreement with the Newtonian sphere-plate systems by Conway and Lee [1].

This paper presents the design, implementation and validation of real-time visual servoing tracking control for a ball and plate system. The position of the ball is measured with a machine vision system. The image processing algorithms of the machine vision system are pipelined and implemented on a field programmable gate array (FPGA) device to meet realtime constraints. A detailed dynamic model of the system is derived for the simulation study.By neglecting the high-order coupling terms, the ball and plate system model is simplified into two decoupled ball and beam systems, and an approximate inputoutput feedback linearization approach is then used to design the controller for trajectory tracking. The designed control law is implemented on a digital signal processor (DSP). The validity of the performance of the developed control system is investigated through simulation and experimental studies. Experimental results show that the designed system functions well with reasonable agreement with simulations.

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