Security lighting in horse riding halls: Development of a simulation-led testing methodology in VR

Abstract

Security lighting plays a vital role for safe evacuation during an emergency such as power outage or a fire related incidence. Installing a security lighting system properly is more crucial for a horse riding facility for two reasons. Firstly, if a sports activity is ongoing at the exact moment of an emergency, the activity needs to be ended safely with the help of security lights to avoid injuries and accidents. Secondly, the security lighting is required so that horses stay calm and do not react from the sudden absence of light. Daylight is scarce between winter solstice to spring equinox in Sweden. This phenomenon makes scheduling events and competitions during completely daylit hours more difficult, especially during the winter, making the facility more dependent on electric lighting.
Emergency situations occur rarely in horse riding halls, thus the cost related to the energy use is not such a big concern. On the other hand, the large volume of occupied space makes it a costly affair to install the whole security lighting system, including cost for lamps, luminaires, controls, and batteries. This study investigates the possibility to introduce new security lighting solutions that can potentially reduce the lighting installation costs, while making the system safer, more secure, and efficient. However, the study does not go into details of the associated costs of the system, rather focuses on the design and visualization of the lighting system.
The main purpose of the study is to adapt a simulation methodology and develop a testing methodology that can be used to design security lighting systems. Installing a trial version of the system in situ to evaluate its performance can be costly and time-consuming. Alternatively, computer-based simulations and visualizations with Virtual Reality (VR) provide a cheaper solution to test and iterate different design solutions. This project focuses on developing a testing methodology in a VR environment that can provide lighting professionals with an immersive experience of their design. In real life situations, the VR environment can also be utilized to let the user group experience the environment and obtain their feedback. This exercise can be helpful in the design process to make informed decisions. To validate this process, the developed VR environment in this project is tested on volunteer participants to get their feedback.
The simulation results suggest that it is possible to provide same level of illuminance in the case building during emergency situations with fewer luminaires and less installed power according to the existing minimum lighting requirement. However, the participants’ feedback as well as test data from the VR experiment suggest that the current minimum requirement for security lighting in the specific building type may not be enough for its occupants to be able to see everything properly and safely evacuate the space during an emergency. The eye tracking data obtained from this study can be analysed in future to get a better understanding of the test participant’s gaze behaviour.

Popular Abstract

Human eyes as living optical devices can do amazing things such as being able to see to some extent in a moonlit night even though the illuminance is lower than 1 lux most of the times. However, this is mostly true when human eyes are properly adapted to the dark environment, which may take up to 30 minutes. The lack of adaptation time in low light conditions in a building during an emergency such as a fire incident or power outage makes it a difficult affair for the occupants to see properly and safely evacuate the space as soon as possible.
Sweden, being situated very close to the Arctic Circle, experiences early sunsets during a major part of the year. The absence of sunlight makes electric lighting in buildings more important even in regular working hours. Local horse riding facilities in Sweden require 300 lux of average illuminance in the horizontal surface of the building during general lighting condition and 5% or 15 lux illuminance for 20 minutes during emergency. If such a situation occurs during an ongoing sports event after the sunset, the building occupants must rely on the security lighting system to evacuate safely.
The main objective of the project was to develop a methodology to test if such a lighting condition is sufficient or not during an emergency. Although the building occupants include both humans and horses, only human visual perception was taken into consideration for this study. Testing how well humans can see in an emergency lighting condition in the case building in reality is a time consuming and costly affair. On the other hand, computer-based simulations and testing can be done in Virtual Reality (VR) in relatively shorter time and minimal cost. Furthermore, this opens up the possibility to develop several lighting design iterations and test them to achieve a comparative analysis. Therefore, the scope of the project was to adapt a simulation methodology and develop a VR testing methodology to test different lighting conditions of the Malmö Civila Ryttareförening building on human subjects. For the purpose of the study, it was hypothesized that the ability to locate objects in different lighting conditions in VR is proportional to the ability to see in those lighting conditions in reality.
While the requirement for security lighting is set at 5% of the required general lighting according to the handbook by Svenska Ridsportförbundet, some other guidelines suggest it to be 10% for certain critical spaces where there might be risk of injuries and accidents. The intention of this project was to test both requirements as well as the general lighting condition of 300 lux to make a comparative analysis. The existing general and security lighting conditions were simulated, and two optimized design iterations were proposed to match the 5% (15 lux) and 10% (30 lux) requirements. Simulations also suggested that the general lighting condition was in photopic adaptation range while the security lighting conditions were predominantly in the mesopic adaptation range. The general lighting condition along with the two security lighting design iterations were chosen as the final three test conditions. These conditions were then rendered from a fixed viewpoint as equirectangular images in a scientifically validated lighting rendering software. The renderings were used to create the VR environment in a game engine. Invisible game objects were programmed and placed inside the virtual environment that can be coupled with eye gaze tracking technology to determine if the objects were seen by the participants.
The test was intended to be a pilot study for future broader research and was conducted on nine participants for this project. The participants’ feedback suggested that they faced difficulty to locate distant objects, objects of specific colours, and objects in darker scenes. Their feedback was in line with the eye gaze tracking and object identification data gathered from the tests. The test data suggests that the participants could identify more objects in 300 lux and 30 lux environments compared to the 15 lux environment. The results of this test indicate that the minimum requirement of 5% security lighting may not be enough for the participants to identify objects in a test environment. More test subjects and further work on the methodology is required to get a definitive answer.
The project can be further developed to conduct broader research for different building types. VR technology has already showed great promise in Architecture, Engineering, and Construction (AEC) industry, and the possibility to incorporate it in lighting design, simulation, and testing process is worth investigating. There are still major technological barriers to overcome, which requires intense research in the upcoming years.

• author: Ahmmad, Sheikh Rishad
• supervisor: Marie-Claude Dubois
• organization: Division of Energy and Building Design; Department of Architecture and Built Environment
• course: AEBM01 20221
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Security lighting, horse riding halls, mesopic vision, Virtual Reality, object tracking
• language: English
• id: 9085166
• date added to LUP: 2022-06-08 09:46:36
• date last changed: 2022-06-08 09:46:36