A general type-2 Fuzzy Logic based Multi-Criteria group decision making for lighting level selection in an intelligent environment

Selecting a suitable lighting level for reading is crucial to the overall success of reading comprehension. The light level preferences vary amongst the various users specifically according to changing environment conditions. Thus, it is important when designing the illumination at various intelligent shared spaces to consider the preferences of users from different backgrounds. Hence, we propose a Fuzzy Logic-Multi Criteria Group Decision Making (FL-MCGDM) system which provides a comprehensive valuation from a group of decision makers utilizes General Type-2 Fuzzy Sets. We have carried out experiments in the intelligent apartment (iSpace) located in the University of Essex. The aggregation operation in the proposed method aggregates the various DMs opinions which allow handling the disagreements of DMs´ opinions into a unique approval. In addition, the proposed system showed agreement between the proposed method and the real decision outputs from DMs (as quantified by the Pearson Correlation) which outperformed the FL-MCGDM systems based on Type-1 Fuzzy Sets, Interval Type-2 Fuzzy Sets and Interval Type-2 Fuzzy Sets with Hesitation Index.