Comparing fuzzy arithmetic with quaternion arithmetic and applying the former to control system analysis

We prove equivalence conditions for arithmetical operations with LR-type fuzzy numbers and for those with quaternions. Our results justify using graphical tools like vector and hodograph diagrams to visualize arithmetical operations. In some cases this equivalence also simplifies algorithms which implement arithmetic operations. We illustrate our approach with the analysis of a control system under fuzzy uncertainty. This paper extends our recent results on comparing arithmetical operations with LR-type fuzzy numbers and those with complex numbers.