How Haptic Rendering works part2(Computer Vision + AI)
- DandelionTouch: High Fidelity Haptic Rendering of Soft Objects in VR by a Swarm of Drones(arXiv)
Author : Aleksey Fedoseev, Ahmed Baza, Ayush Gupta, Ekaterina Dorzhieva, Riya Neelesh Gujarathi, Dzmitry Tsetserukou
Abstract : To achieve high fidelity haptic rendering of soft objects in a high mobility virtual environment, we propose a novel haptic display DandelionTouch. The tactile actuators are delivered to the fingertips of the user by a swarm of drones. Users of DandelionTouch are capable of experiencing tactile feedback in a large space that is not limited by the device’s working area. Importantly, they will not experience muscle fatigue during long interactions with virtual objects. Hand tracking and swarm control algorithm allow guiding the swarm with hand motions and avoid collisions inside the formation. Several topologies of the impedance connection between swarm units were investigated in this research. The experiment, in which drones performed a point following task on a square trajectory in real-time, revealed that drones connected in a Star topology performed the trajectory with low mean positional error (RMSE decreased by 20.6% in comparison with other impedance topologies and by 40.9% in comparison with potential field-based swarm control). The achieved velocities of the drones in all formations with impedance behavior were 28% higher than for the swarm controlled with the potential field algorithm. Additionally, the perception of several vibrotactile patterns was evaluated in a user study with 7 participants. The study has shown that the proposed combination of temporal delay and frequency modulation allows users to successfully recognize the surface property and motion direction in VR simultaneously (mean recognition rate of 70%, maximum of 93%). DandelionTouch suggests a new type of haptic feedback in VR systems where no hand-held or wearable interface is required.
2.Passive Realizations of Series Elastic Actuation: Passivity and Effects of Plant and Controller Dynamics on Haptic Rendering Performance (arXiv)
Author : Celal Umut Kenanoglu, Volkan Patoglu
Abstract : We establish the necessary and sufficient conditions for the frequency domain passivity of series (damped) elastic actuation (S(D)EA) while rendering null impedance and ideal springs under velocity sourced impedance control (VSIC). We introduce passive physical equivalents for S(D)EA under closed-loop control to help establish an intuitive understanding of the passivity bounds and to highlight the effect of different plant parameters and controller gains on the closed-loop performance of the system. Through the passive physical equivalents, we rigorously compare the effect of different plants dynamics (e.g., SEA and SDEA) and different cascaded controller architectures (e.g., P-P and P-PI) on the system performance. We show that passive physical equivalents establish a natural means for effective impedance analysis. We provide experimental validations of our theoretical results and evaluate the haptic rendering performance of S(D)EA under VSIC.
