Roll axis tracking improvement resulting from peripheral vision motion cues

Author(s):  
Thomas E. Moriarty ◽  
Andrew M. Junker ◽  
Don R. Price
2015 ◽  
Vol 119 (1211) ◽  
pp. 23-44 ◽  
Author(s):  
S.J. Hodge ◽  
P. Perfect ◽  
G.D. Padfield ◽  
M.D. White

AbstractThis paper presents findings from research conducted at the University of Liverpool aimed at optimising the motion cues available from a short-stroke hexapod motion platform. Piloted simulations were conducted for a typical helicopter low-speed sidestep manoeuvre. To correctly simulate the sidestep manoeuvre the motion platform must translate laterally at the same time as it rolls. If the motion in these two axes is not properly harmonised then the pilot can experience significant false motion cues. This is a particular concern for short-stroke hexapod platforms, where displacement limits can severely constrain the available lateral travel particularly during motion in multiple axes (e.g. roll and sway). During the experiment the motion filter gains in the roll and sway axes and the roll-axis motion filter break-frequency were varied. Objective and subjective measures of pilot performance and motion fidelity were gathered for each motion filter configuration, the latter using a new motion fidelity rating scale. The key findings show that acceptable motion cues could only be achieved by careful harmonisation of the motion filter gains in the roll and sway axes. A high gain in the roll axis coupled with a low gain in the sway axis resulted in motion which was abrupt and uncomfortable. On the other hand, too large a gain in the sway axis resulted in extreme lateral displacements of the motion platform leading to undesirable side-effects. The phase distortion between the visual and platform motion cues, introduced by the roll-axis motion filter, also had a significant impact on the pilot’s perception of motion fidelity. These results are presented in the form of proposed motion fidelity criteria for short-stroke hexapod platforms and compared with results from previous research conducted on a range of large motion systems.


Author(s):  
Matthew Ward ◽  
Amit Barde ◽  
Paul N. Russell ◽  
Mark Billinghurst ◽  
William S. Helton

Current head mounted displays (HMDs) cover only a small section of the user’s visual field, preventing the use of peripheral onset cues. This study investigates whether a centrally positioned cue can use the pursuit motion reflex to reorient attention away from HMDs more quickly than arrow cues. Thirty participants recruited from the University of Canterbury campus were required to find and mark targets which appeared within a 200° visual arc of a central focused position after being given no directional cue, an arrow cue or a pursuit motion cue. A subgroup of less than half of the participants failed to extract directional information from pursuit motion cues and the remaining participants responded more slowly to the pursuit cues than the arrow cues. Arrow cues were responded to only 40ms slower than targets appearing within the participants’ peripheral vision indicating that the search for a reflexive orientation cue may be unnecessary.


2008 ◽  
Vol 31 (6) ◽  
pp. 1608-1622 ◽  
Author(s):  
D. M. Pool ◽  
M. Mulder ◽  
M. M. Van Paassen ◽  
J. C. Van Der Vaart

1975 ◽  
Author(s):  
Mark Kirkpatrick ◽  
Nicholas Shields ◽  
Ronald Brye ◽  
Frank L. Vinz
Keyword(s):  

2013 ◽  
Vol 133 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Kensuke Tobitani ◽  
Kunihito Kato ◽  
Kazuhiko Yamamoto
Keyword(s):  

Author(s):  
Alex F. Lim ◽  
Jonathan W. Kelly ◽  
Nathan C. Sepich ◽  
Lucia A. Cherep ◽  
Grace C. Freed ◽  
...  

2020 ◽  
pp. bjophthalmol-2020-317034
Author(s):  
Meghal Gagrani ◽  
Jideofor Ndulue ◽  
David Anderson ◽  
Sachin Kedar ◽  
Vikas Gulati ◽  
...  

PurposeGlaucoma patients with peripheral vision loss have in the past subjectively described their field loss as ‘blurred’ or ‘no vision compromise’. We developed an iPad app for patients to self-characterise perception within areas of glaucomatous visual field loss.MethodsTwelve glaucoma patients with visual acuity ≥20/40 in each eye, stable and reliable Humphrey Visual Field (HVF) over 2 years were enrolled. An iPad app (held at 33 cm) allowed subjects to modify ‘blur’ or ‘dimness’ to match their perception of a 2×2 m wall-mounted poster at 1 m distance. Subjects fixated at the centre of the poster (spanning 45° of field from centre). The output was degree of blur/dim: normal, mild and severe noted on the iPad image at the 54 retinal loci tested by the HVF 24-2 and was compared to threshold sensitivity values at these loci. Monocular (Right eye (OD), left eye (OS)) HVF responses were used to calculate an integrated binocular (OU) visual field index (VFI). All three data sets were analysed separately.Results36 HVF and iPad responses from 12 subjects (mean age 71±8.2y) were analysed. The mean VFI was 77% OD, 76% OS, 83% OU. The most common iPad response reported was normal followed by blur. No subject reported dim response. The mean HVF sensitivity threshold was significantly associated with the iPad response at the corresponding retinal loci (For OD, OS and OU, respectively (dB): normal: 23, 25, 27; mild blur: 18, 16, 22; severe blur: 9, 9, 11). On receiver operative characteristic (ROC) curve analysis, the HVF retinal sensitivity cut-off at which subjects reported blur was 23.4 OD, 23 OS and 23.3 OU (dB).ConclusionsGlaucoma subjects self-pictorialised their field defects as blur; never dim or black. Our innovation allows translation of HVF data to quantitatively characterise visual perception in patients with glaucomatous field defects.


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