A Cost-Effective Illuminance Sensor for DaylightHarvesting Lighting Control Systems

2020 ◽  
pp. 103-110
Author(s):  
Moutusi Bag ◽  
Saswati Mazumdar ◽  
Kalyan Kumar Ray

A cost-effective two-wire industrial standard illuminance sensor (4–20) mA has been proposed. It can be used for daylight harvesting control of indoor illuminance and other applications. The basic sensor used is a cadmium sulphide (CdS) light dependent resistor, whose relative spectral characteristic almost corresponds to the human eye. The method of sensor calibration has been presented and static and dynamic performance characteristics of the sensor have been experimentally determined.

2021 ◽  
Vol 2042 (1) ◽  
pp. 012123
Author(s):  
Ö Karaman Madan ◽  
MK Pekeriçli

Abstract Suitable lighting control strategies are essential for energy efficiency in buildings. Occupancy sensors are highly promoted by the building codes as one of the most cost-effective solutions in the sector. However, widespread use of these systems is still limited due to lack of user satisfaction. In this study, it is hypothesized that the “conventional use” of occupancy sensors (where user steps inside a dark area, and only afterwards the area becomes lit) is the reason behind the dissatisfaction. To overcome this problem, a new user-centric sensor-based lighting control approach is proposed in this study where users walk into an already lit area. An experiment was carried out in the circulation areas of a university building to test the feasibility of the proposed scenarios along with a conventional occupancy sensor scenario and the existing “no sensor” scenario. The main results revealed that the conventional use of occupancy sensors was not favoured by the participants in circulation areas while use of the proposed user-centric approach was as favourable as the existing constantly lit situation. It is the claim of this study that both energy efficiency and user satisfaction can be provided by the use of user-centric control systems.


Author(s):  
Prince U.C. Songwa ◽  
Aaqib Saeed ◽  
Sachin Bhardwaj ◽  
Thijs W. Kruisselbrink ◽  
Tanir Ozcelebi

High-quality lighting positively influences visual performance in humans. The experienced visual performance can be measured using desktop luminance and hence several lighting control systems have been developed for its quantification. However, the measurement devices that are used to monitor the desktop luminance in existing lighting control systems are obtrusive to the users. As an alternative, ceiling-based luminance projection sensors are being used recently as these are unobtrusive and can capture the direct task area of a user. The positioning of these devices on the ceiling requires to estimate the desktop luminance in the user's vertical visual field, solely using ceiling-based measurements, to better predict the experienced visual performance of the user. For this purpose, we present LUMNET, an approach for estimating desktop luminance with deep models through utilizing supervised and self-supervised learning. Our model learns visual representations from ceiling-based images, which are collected in indoor spaces within the physical vicinity of the user to predict average desktop luminance as experienced in a real-life setting. We also propose a self-supervised contrastive method for pre-training LUMNET with unlabeled data and we demonstrate that the learned features are transferable onto a small labeled dataset which minimizes the requirement of costly data annotations. Likewise, we perform experiments on domain-specific datasets and show that our approach significantly improves over the baseline results from prior methods in estimating luminance, particularly in the low-data regime. LUMNET is an important step towards learning-based technique for luminance estimation and can be used for adaptive lighting control directly on-device thanks to its minimal computational footprint with an added benefit of preserving user's privacy.


1969 ◽  
Vol 2 (3) ◽  
pp. T29-T33 ◽  
Author(s):  
F. M. Toates

The control systems of accommodation and convergence in the human eye are theoretically examined, together with their interactions which represent accommodative convergence and convergence induced accommodation. A control model is proposed in order to help to understand the system, and it is used to make predictions concerning accommodation and convergence placed in conflict, monocular vision, fusional after-effects and the effect of age and drugs on accommodation and accommodative convergence. In each case the theoretical predictions are compared with established experimental results.


Energy ◽  
2021 ◽  
pp. 121391
Author(s):  
JunYoung Choi ◽  
DongChan Lee ◽  
Myeong Hyen Park ◽  
Yongju Lee ◽  
Yongchan Kim

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ashutosh Kumar ◽  
S. K. Kakoty

The present study analyzes the effect of pressure dam depth and relief track depth on the performance of three-lobe pressure dam bearing. Different values of dam depth and relief track depth are taken in nondimensional form in order to analyze their effect. Results are plotted for different parameters against eccentricity ratios and it is shown that the effect of pressure dam depth and relief track depth has great significance on stability and other performance parameters. Study of stability and performance characteristics is undertaken simultaneously.


2018 ◽  
Vol 13 (4) ◽  
pp. 1037-1056 ◽  
Author(s):  
Huthaifa AL-Khazraji ◽  
Colin Cole ◽  
William Guo

Purpose This paper aims to optimise the dynamic performance of production–inventory control systems in terms of minimisation variance ratio between the order rate and the consumption, and minimisation the integral of absolute error between the actual and the target level of inventory by incorporating the Pareto optimality into particle swarm optimisation (PSO). Design/method/approach The production–inventory control system is modelled and optimised via control theory and simulations. The dynamics of a production–inventory control system are modelled through continuous time differential equations and Laplace transformations. The simulation design is conducted by using the state–space model of the system. The results of multi-objective particle swarm optimisation (MOPSO) are compared with published results obtained from weighted genetic algorithm (WGA) optimisation. Findings The results obtained from the MOPSO optimisation process ensure that the performance is systematically better than the WGA in terms of reducing the order variability (bullwhip effect) and improving the inventory responsiveness (customer service level) under the same operational conditions. Research limitations/implications This research is limited to optimising the dynamics of a single product, single-retailer single-manufacturer process with zero desired inventory level. Originality/value PSO is widely used and popular in many industrial applications. This research shows a unique application of PSO in optimising the dynamic performance of production–inventory control systems.


2013 ◽  
Vol 340 ◽  
pp. 601-605
Author(s):  
Lin Li ◽  
Chang Ji Shan ◽  
Jun Luo

With the speedy development of Auto-industry, CAN-BUS technology is becoming more and more mature day after day. This paper makes a study of the application of CAN-BUS technology in lighting control systems and failure finding model while making an analysis of the characteristics of the application of CAN-BUS technology in Auto-motive Network which paves way for the further studies of CAN-BUS technology.


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