Modern missile systems use infrared imaging for tracking or target detection algorithms. The development and
validation processes of these missile systems need high fidelity simulations capable of stimulating the sensors in
real-time with infrared image sequences from a synthetic 3D environment.
The Extensible Multispectral Image Generation Toolset (EMIT) is a modular software library developed at MBDA
Germany for the generation of physics-based infrared images in real-time. EMIT is able to render radiance images in
full 32-bit floating point precision using state of the art computer graphics cards and advanced shader programs.
An important functionality of an infrared image generation toolset is the simulation of thermal shadows as these may
cause matching errors in tracking algorithms. However, for real-time simulations, such as hardware in the loop
simulations (HWIL) of infrared seekers, thermal shadows are often neglected or precomputed as they require a
thermal balance calculation in four-dimensions (3D geometry in one-dimensional time up to several hours in the
In this paper we will show the novel real-time thermal simulation of EMIT. Our thermal simulation is capable of
simulating thermal effects in real-time environments, such as thermal shadows resulting from the occlusion of direct
and indirect irradiance. We conclude our paper with the practical use of EMIT in a missile HWIL simulation.
In the infrared spectrum, two contributions to shadows exist: one part is reflective shadows resulting from occlusion of instantly reflected infrared rays, and the other part is thermal (IR) shadows occurring through occlusion of irradiance in the past. The realization of thermal shadows requires a thermal balance calculation in four-dimensions (three-dimensional geometry in one-dimensional time), which is computationally expensive, and therefore mostly used for nonreal-time simulations. We present an approximation of thermal shadows resulting from the occlusion of direct rays from IR emitters. Our approach uses programmable graphics cards to achieve real-time frame rates in scenes with dynamic geometry.
This paper deals with the simulation of the fluid-structure interaction phenomena in micropumps. The proposed solution approach is based on external coupling of two different solvers, which are considered here as `black boxes'. Therefore, no specific intervention is necessary into the program code, and solvers can be exchanged arbitrarily. For the realization of the external iteration loop, two algorithms are considered: the relaxation-based Gauss-Seidel method and the computationally more extensive Newton method. It is demonstrated in terms of a simplified test case, that for rather weak coupling, the Gauss-Seidel method is sufficient. However, by simply changing the considered fluid from air to water, the two physical domains become strongly coupled, and the Gauss-Seidel method fails to converge in this case. The Newton iteration scheme must be used instead.
This paper deals with the application of laser- interferometric vibration measurement for experimental characterization of beams and membranes in micromechanical devices. Such small structures are used in many sensor and actuator applications, where they represent the functional key elements. Due to the down-scaled geometrical size and to the fabrication process, the behavior is strongly influenced by many interactions and cross-coupling effects, which are extremely difficult to describe by theoretical models. For demonstration, two different examples are examined: a piezoelectric driven micropump and a 2D-scanning mirror device. The measured data can be compared to the simulated behavior of the structures, and contains important information for the optimum design of the devices. The two main conclusions are, that firstly certain effects of these devices can not be described by theoretical models alone, but have to be combined with experimental measurements, and secondly, that the deflection curvature of the structures must be determined by scanning rather than single-point measurements.
A new micropump principle without mechanical valves is proposed. Flow rectification is achieved by a pair of dynamic valves, the pressure drop through each of which can be individually adjusted by controlling the liquid temperature in the valve channel, thus changing its viscosity. This method has a potential for miniaturization of complex liquid handling systems, since it allows bi- directional liquid transfer with a single micropump, by applying appropriate activation sequences for the valves and the pressure source. The necessary specification and the possible performance are predicted through FEM analysis of thermal and flow systems. By a preliminary experiment using a prototype pump structure fabricated with silicon based technology, the basic function of the valve elements has been confirmed.