Hardware Overview

1
Hardware Overview

• Draft 10/01/04

2
HW Overview Tracking System

• Functional Requirements
• Provides 6 DOF (position and orientation)
  information for head, hand, torso
• Operate in a 2 m3 workspace
• Tracking accuracy and precision at a millimeter
  level
• Sampling rate at 60Hz minimum (ideally 180 Hz)
• Minimal end-to-end latency
• Combines the Charnwood Dynamicsoptical and
  Intersense inertial tracking systems.

3
HW Overview Head Display

• Functional Requirements
• Stereoscopic, wide field-of-view, hi-resolution
• Operable by subjects wearing glasses
• Block the view of the outside environment
• Simple minimal adjustments
• Modified COTS nVis nVisor SX provides the best
  compromise ofcost, performance, ergonomics.

4
HW Overview Headphones

• Functional Requirements
• Provide monaural signal from area microphone to
  eliminate directional sound cues to subjects.
• Modified COTS Bose QC-2 headphones worn in an
  inverted position below the Head Display

5
HW Overview Paddle/Handswitch

• Functional Requirements
• Paddle should be usable with either hand
• Handswitch has one button and one trigger
• Track hand acceleration with a 200Hz sampling
  rate.
• Paddle contains one Inertiacube and a set of LED
  markers for tracking and an accelerometer.
• Handswitch is modified COTS.

6
HW Overview Joystick

• Functional Requirements
• Minimum of one joystick and two buttons to
  respond to visual stimuli.
• Leave additional joystick and buttons for
  redundancy can easily reprogram experiments to
  use new buttons.

7
HW Overview Vest

• Provides attachment points for pole, springs, and
  temp stow of peripherals.
• Distributes the load of the springs to hips and
  shoulders.
• Adjustable for subject size and distribution of
  forces.

8
HW Overview Restraint Springs

• Functional Requirements
• Provides a minimum 32 lbs per spring.
• Provides a force coefficient of lt 0.6 lbs/in when
  extended from 10-30 inches
• Requires no adjustment to fit different size
  crewmembers.
• Same design used for Neurolab experiments.

9
HW Overview Restraint Platform

• Functional Requirements
• Provide a back rest for seated position.
• Provide a platform for subjects to lie flat.
• Provide restraint straps for safety.

10
HW Overview Restraint Pole

• Functional Requirement
• Provide a means for free rotational drift within
  the trackers workspace.
• Flexible design to accommodate a larger number of
  attachment points on seat track.

11
HW Overview Subject Camera

• Functional Requirements
• Provides a means to capture still images to the
  R2WS.
• Capture subject positioning during trials.
• Modified COTS Logitech USB camera.

12
HW Overview Block Diagram
13
HW Overview Pre-flight BDC

• Assume pre-flight BDC occurs at JSC
• Uses VOILA Training Hardware for BDC
• Flight-like R2WS with monitor, keyboard
• Springs, Pole, Platform are not used for BDC
• Uses tripods to deploy Camera Bars
• Assorted table, chairs, shelves, emesis basin,
  gurney bed
• Additional BDC hardware
• Whole body tilt chair (45 roll)
• Tilt bed (30 earth-horizontal axis)

14
HW Overview Post-flight BDC

• Assume post-flight occurs in Russia
• R28/45 data collection to occur at JSC
• Uses COTS or engineering prototype versions of
  experiment equipment
• Does NOT require the use of a R2WS
• Need NASA provided power converters
• Equipment stays in Russia for entire VOILA
  project.
• Tilt bed and tilt chair remain at JSC for R28/45
  testing