Using of computer intelligence for design of lightning systems in industry plants.

Wessely, Emil ; Kralikova, Ruzena ; Krupa, Marek 等

Key words: environment, lightning, simulation, method

1. INTRODUCTION

Designing internal artificial lighting as part of the work or the environment is subject to certain rules, which derive from the nature of the illumination. Good lighting has an impact on visual comfort, reliability, visual performance, quality work and security. In compliance with all quantitative and qualitative parameters of illumination, we must design a lighting system based on the principles of maximum performance. We can economize electricity especially if we would selected a new generation of lamps, i.e. with long life and high efficiency. Lighting systems with a solid operation, regulations and management of lighting should also significantly contribute to energy savings.

2. MODELING OF LIGHT PARAMETERS

In the past there were three basic types of light-technical models:

1. calculation (without taking into account the actual dimensions, with tables),

2. accurate (for models in the scale 1:1),

3. using mock-ups which generates a display image which is similar to a visual perception of designed lighting system.

Currently, is in the light-technical modeling used a different approach, which is based on computer visualization of spatial scenes of designed lighting system. In this case are the light-implemented calculations with the given precision without the use of costly physical models (Daneshjo, 2003). The computer visualization, which goal is to show the photo, is often described in detail the model and simulates the propagation of light in space. Modern visualization programs could reproduce the brightness, color and surface structure of the complex three-dimensional space rather realistic, since in the calculations include inter reflection of light between surfaces in space and in many optical effects arising throught the day, an artificial joint or lighting. Simulation methods are based on classical optical, thermodynamic, respectively light-technical models of the spread of radiation (Budak et al., 2006).

3. SIMULATION METHODS

There are two basic methods used in computer simulations luminous environment, namely Monte Carlo method, in which does apply technology tracking light beams (raytracing, this name is used for follow-up of beams, also used the term "ray casting" sending light beam when a beam of light comes from the light source), and radiation (radiosity). From a physical point of view, both methods are similar and the difference lies in algorithmization. The method of monitoring the beam has a very small spot stochastic manner (results of re-calculation may be different slightly). The radiation method of working with larger surfaces deterministically (repeated calculation results are always the same).

3.1 Simulation Monte Carlo methods and the calculation of direct and indirect lighting

The furnished rooms with surfaces that have different optical properties, with the advantage of the stochlastic (probability) luminosity calculation, are often referred to as the Monte Carlo method. Generally, these methods used a large number of random light beams or posted particles of bearing energy. Their movement in the space underlie to physical laws and to monitoring itself. Accurate calculation could be done if it has been shown that it followed the path of each photo, which is of course a number of reasons. However, if accidentally it sends a sufficient number of rays (particles), e.g. 50 million, will also correspond to the calculation lighting with high demand for accuracy (Rybar et al., 2001). As the monitors spread of light from the source to the environment, usually talking about the method of monitoring particles (Fig.1a) or method of tracing rays (Fig.1b) when the monitor path of light rays in the direction of the observer to the light source.

The method of tracing rays in the direction of the observer sends through each point on the display screen (pixel) virtual beam of light and it tested to its intersection with all objects in that space. Finds the nearest intersection, which is a visible place on the stage. It generates additional rays. Towards the light source are transmitted rays to determine whether a visible place it overshadowed with some objects. As the surface is shiny and mirrored objects, a mirror is reflection of the primary beam. In the case the surface is transparent, created beams are representing the light reflection and refraction by the optical properties of transparent material. As the surface is nontransparent, generating the beams (often more than 100) simulation of light reflection from the surface (Chen et al., 1991).

In principle, beam-tracing technic it solves the following integral equation the energy balance of each nearly all the same on surfaces in space.

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (1)

[theta]--polar angle measured from the surface at normal levels,

[phi]--Azimuthal angle surface at normal levels,

[L.sub.e]([[theta].sub.r], [[theta].sub.r])--Its own radiation (as is the area's primary source of radiation) [W x [sr.sup.-1] x [m.sup.-2]],

[L.sub.e]([[theta].sub.r], [[theta].sub.r])--The total radiation [W x [sr.sup.-1] x [m.sup.-2]],

[L.sub.i]([[theta].sub.i], [[theta].sub.i])--incident radiation [W.[sr.sup.-1] x [m.sup.-2]],

[[rho].sub.bd]([[theta].sub.i], [[phi].sub.i], [[theta].sub.I], [[phi].sub.r])--Two-way distribution of reflectivity function [[sr.sup.-1]].

3.2 Radiation methods and radiation equation

Although the ray-tracing algorithm (raytracing) deflect a perfect record on the mirrored reflectivity and modeling undispersional refractonal transparency, but this algorithm has a shortcoming. And while that does not take into account the physical laws of some important visual effects, for example stain shade, the influence of reflection of light from another object. It is due to the fact that raytracing only monitors the final number of rays emanating from the observer's eye. This failure is trying to remove the radiation method. Radiation method can be seen as a generalization of methods to monitor the beam. In this method assumes that all surfaces are ideal primary or secondary diffuse light sources (Fig.1c), or it is combination of sources. The advantage of this method in terms of visualization, and algorithm development is that the surfaces luminosity can be calculated independently of the direction to visual scene (Dutre et al, 2003)

[FIGURE 1 OMITTED]

In the algorithm for shading of the light sources are always considered independently from the surface to light. In contrast, the radiation method allows any surface emit light, i.e., all light sources are modeled naturally as an active surface. Consider the distribution environment for the final number of n an discrete surface (patches), each of which has the final size and emits and reflects light evenly across its surface. Sets therefore consist of surfaces, acting also as light sources and reflective surfaces such as creating a closed system. If we consider each area of the opaque Lambertian diffuse emitter and reflector, then applies for the area and because of the energy conservation equation:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (2)

[B.sub.i], [B.sub.j]--the intensity of radiation (radiation) areas i and j, measured in units of energy per unit area (W/[m.sup.2])

[E.sub.i]--energy of light radiated from the surface s has the same dimension as the radiation,

[p.sub.i]--the reflection coefficient (reflectivity) is the dimensionless area ia,

[F.sub.j-i]--configuration dimensionless factor (form-factor), which specifies the energy leaving the surface ja incoming area and taking into account the shape, relative orientation of both areas as well as the presence of any areas that could mislead. The configuration factor takes its values from interval <0.1>, while the fully covered surface takes the value 0,

[A.sub.i], [A.sub.j]--surface levels (i, j).

Equation shows that the energy leaving the unit part of the surface is the sum of light emitted by a reflection. Reflected light is calculated by multiplying the reflection coefficient and the amount of incident light. Incident light is on the contrary, the sum of the light leaving the whole area, as part of the light which reaches the receiving unit content area. [B.sub.j][F.sub.j-i] is the amount of light leaving the unit and content area and the incident on the entire space of [A.sub.i]. It is therefore necessary to multiply the equation of the ratio and/[A.sub.i] for the determination of light, leaving the entire incident and also surface-to-surface [A.sub.i] (Silion & Puech, 1994).

4. OUTPUTS FROM THE PROPOSAL OF LIGHTING SYSTEM

Currently, the development of computer graphics software products exist to enable a comprehensive design and calculation of parameters of lighting systems, which would reflect light effects that arise in artificial and day lighting. In consequence, the market appeared to be several light-technical programs with different purposes and uses. For purposes of this contribution to the possibilities of simulation outputs in the DIALux 4.7. The above simulation program offers the following options selected lighting system and various options for presentation of results (Fig.2) as graph values, izofotic lines (Fig.2a), light maps (Fig.2b), false color rendering (Fig.2c, Fig.2d), summary table of lighting respectively, brightness, three-dimensional model lighting respectively (Fig.2e), economic evaluation of the lighting project in terms of energy consumption, visualization of sunshine and so on.

[FIGURE 2 OMITTED]

5. CONCLUSION

Primary role in creating the work environment are optimal conditions of vision for safe working ensure. Visibility must therefore be seen as a precondition for the realization of high quality, safe and reliable operation work. This issue is necessary to pay close attention. Just when dealing with light-technical projects is a useful visualization tool lighting parameters using realistic lighting display parameters.

6. REFERENCES

Budak, V. P.; Makarov, D. N. & Smirnov, P. A. (2006). Overview and comparison of computer programs for the design of lighting systems, In.: Light 1/2006, FCC Public Ltd., ISSN 1212-0812

Chen, S. E. ; Rushmaier, H.; Miller, G. & Turner, D. (1991). A progressive multi- pass method for global illumination, Computer Graphics, vol. 25/4, July 1991, 165- 174, ISBN 0-201-56291-X

Daneshjo, N. (2003). Modeling and simulation. Machinery. Vol. 7, No. 12, s. 44-45, ISSN 1335-2938

Dutre, P.; Bekaert, P. & Bala, K. (2003) Advanced Global Illumination, AK Peters, Ltd ISBN 15-68811-77-2, Wellesley, MA

Rybar, P. et al. (2001). Daylight and insolation of Buildings. ERA group Ltd., ISBN 80--86517--33--0, Brno, Czech Republic

Silion, F. & Puech, C. (1994). Radiosity and Global Illumination, Morgan Kaufmann, ISBN 15-58602-77-1, San Francisco, CA