The Virtual Haptic Back Project: VR Equipment

Haptics:

Our initial VHB model was developed for a single PHANToM 1.0.

We now enable dual-fingered (or -thumbed) palpation via two PHANToM 3.0s.

We also will use a Microsoft Sidewinder for virtual human trunk motion.

We have recently procured an Immersion CyberGrasp haptic glove.

We have a 6-dof PHANToM which allows moment feedback in addition to force feedback.

We bought a PHANToM Omni for traveling demos and commercial potential investigation

We have developed a haptic playback system for improved training and D.O. instructor evaluations.

Graphics:

We currently use a 23” flat screen monitor for the VHB image (as seen above with the PHANToM 3.0s). We are investigating two graphical systems to improve viewing and increase the feeling of telepresence. Both systems (explained below) may be adapted for 3D viewing: 1) HMD/Flock of Birds; 2) View at fingertips.

During the past 2003-2004 project year we procured and implemented a head-mounted display (HMD) system. This is a visual device, bringing the monitor output directly to the human in terms of two small screens, directly over the right and left eyes (see Figure 1). The purpose of this is to make the VHB user feel more immersed in the virtual back environment. In conjunction with the HMD we procured a head tracking device, called the Flock of Birds (FoB, see Figure 2; the sensor is on the HMD of Figure 1), wherein via magnetic sensing the computer determines the position and orientation of the human user’s head in space. We have implemented this system and use the position and orientation information to provide the user views through the HMD which are very natural, just like moving and rotating your head in the real world.

Figure 1. Head-Mounted Display Figure 2. Flock of Birds

We have become aware of a powerful visualization tool, implemented by the Human Simulation Laboratory at the University of Colorado, Denver, wherein the monitor display is projected via mirrors and see-through glass so that the simulated graphical images appear to be at the user’s fingertips. This is suitable for use with haptic feedback. Currently, our VHB model is on the PC monitor (23” flat screen, real human scale); however, this screen is 8-12” behind the actual VHB, i.e. where the user feels the back to be. Therefore, we have a potential cognitive dissonance between where the back is seen and felt. We have made designs and are currently building and evaluating them to improve this problem, i.e. to project the VHB image directly to the user’s fingertips. This represents a potential major improvement in realism. Please see the figures below for our conceptual design alternatives.

Figure 3a. Conceptual Design 1 Figure 3b. Conceptual Design 2

Figure 4a. Detailed Design 1 Figure 4b. Detailed Design 2

Figure 5a shows the initial implementation for the design of Figures 3a and 4a. Figure 5b shows the user’s view in the same system. The result is very compelling to the user, i.e. the user’s finger in the PHANToM thimble (hard to see in Figure 5b since it is black) appears to be actually touching the virtual object which does not exist – but it feels like it does!

Figure 5a. Haptics/Graphics Implementation

Figure 5b. Detailed View of Figure 5a

Meng-Yun Chen developed a human motion animation from the skeletal structure up.

Other:

In addition to haptics and graphics, we use a foot switch for user interaction and sound feedback to aid in training.