Tsai C.-YTsai I.-LLai C.-JChow DWei LLUNG-PAN CHENGYEN-YANG CHEN2023-06-092023-06-092022https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130558714&doi=10.1145%2f3491102.3502034&partnerID=40&md5=3d9eb10e12d0eb3dba4393dfc01a49cahttps://scholars.lib.ntu.edu.tw/handle/123456789/632266We present AirRacket, perceptual modeling and design of ungrounded, directional force feedback for virtual racket sports. Using compressed air propulsion jets to provide directional impact forces, we iteratively designed for three popular sports that span a wide range of force magnitudes: ping-pong, badminton, and tennis. To address the limited force magnitude of ungrounded force feedback technologies, we conducted a perception study which discovered the novel illusion that users perceive larger impact force magnitudes with longer impact duration, by an average factor of 2.57x. Through a series of formative, perceptual, and user experience studies with a combined total of 72 unique participants, we explored several perceptual designs using force magnitude scaling and duration scaling methods to expand the dynamic range of perceived force magnitude. Our user experience evaluation showed that perceptual designs can significantly improve realism and preference vs. physics-based designs for ungrounded force feedback systems. © 2022 ACM.air propulsion; force perception; Haptics; perceptual design; ungrounded force feedback; virtual reality[SDGs]SDG7Compressed air; Iterative methods; Propulsion; Sports; Virtual reality; Air propulsion; Directional forces; Force magnitude; Force perception; Force-feedback; Haptics; Impact force; Perceptual design; Perceptual modelling; Ungrounded force feedback; Feedbackconference paper10.1145/3491102.35020342-s2.0-85130558714