Human Threshold Model for Perceiving Changes in System Dynamics

Abstract

Limitations of a haptic device can cause distortions of the force feedback it presents. Just-noticeable difference (JND) in system dynamics is important for creating transparent haptic interaction. Based on the previous work, this article presents a unified model that extends the existing JND rule. Our approach projects the JNDs in the mechanical properties of a second-order mass-spring-damper system onto the real and imaginary components of the system's frequency response function (FRF). We discuss the results of two experiments and show that the JNDs obtained for both the real and imaginary components can be expressed as the same fraction of, and thus are proportional to, the magnitude of the total system's FRF. Furthermore, the findings are generalized to cases where the system's dynamics order is different than two. What results is a unified model that accurately describes the threshold for changes in human perception of any linear system dynamics with only two dimensions: the real and imaginary axes in the complex plane.

Eigenmode Distortion: A New Perspective on Motion Cueing Fidelity in Flight Simulation

“…While it is evident that the longitudinal specific force cue is improved as 3 is increased (i.e., with attentuation pitch motion cues), there are no intuitive fidelity criteria or boundaries in the modal domain akin to those offered by, e.g., the Sinacori-Schroeder criteria or the OMCT. While it is possible to define similar boundaries in the modal domain as demonstrated, e.g, for application to haptic feedback systems Fu et al [42], this is more complicated for motion cueing fidelity. This is because individual vehicle modes are rarely excited in isolation.…”