Treadmill Based Three Tether Parallel Robot for Evaluating Auditory Warnings While Running

Abstract

We design and test a 3 DoF parallel cable system capable of applying precise and accurate impulses to walking and running subjects for the University of Utah's Treadport Active Wind Tunnel (TPAWT). Using Nexus VICON motion capture and gait algorithms, perturbations can be applied at different points in the subject's gait. The use of a PID force controller allow the system to create omnidirectional perturbations with walking and running subjects while having the capability to vary amplitude and direction of perturbations. Analysis is presented of the workspace of the large treadmill to test whether the workspace available to activate these perturbations is safe. This paper reports the efficacy of the system and evaluates how warning a runner before impact may affect their displacement. Participants experienced 48 perturbations while running applied with a random combination of a front/back/left/right impact at either toe-off or mid-stance with or without warning. A two sample T-test reveals that warning a runner before impact significantly reduced the magnitude they were displaced for both toe-off (t(46) = 4.98 p<; .001) and mid-stance (t(46) = 3.44, p = .001).