Month / August 2018

by dshah1120

AR Industrial Applications: Defense Engineering

What is this? I chatted with Evan, Operations Modeling and Simulation Engineer at Northrop Grumman about engineering use cases for the Hololens. 

His opening remarks: It’s often a struggle integrating new technology into large-scale manufacturers due to adherence to strict methods and processes. Finding/molding problems into good use cases for a given new technology can be challenging. It’s much easier to start with the problem and find/mold a good solution than the other way around. The challenge is helping engineers and operations leadership understand what modern solutions exist.

 

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Evan’s Take: In the context of engineering, to show the Hololen’s capabilities in relation to the (DOD acquisition lifecycle) lifecycle stages of a product might be a high value strategy.

Image result for dod engineering systemTemporary Minimum Risk Route (TMRR): How do we design a product that fulfills mission requirements? This can take the form of:

  • visualizing the designs, making sure they’re feasible (i.e. are wires getting pinched?). Uncovering design flaws you’ll discover later in the form of defects during manufacturing. Making sure the design is producible (DFM – Design for Manufacturability).
  • communicating to the customer: In that stage of the lifecycle it’s important to be able to communicate your designs to the customer to demonstrate technical maturity.
    • inspect the product: this part of the product is called “XYZ” can then be exploded.

 

Engineering and Manufacturing Development (EMD): At this stage the customer (NG) cares about “how are we going to build it”

  • tooling design: visualizing the product sitting in the tools or workstands that will be used in production
  • visualizing the ergonomics people are going to have to deal with for example are the clearances sufficient to *screw in the screw, so ergonomics*
  • visualizing the factory flow, the customer (NG’s customer) would also be interested in seeing the proposed factory flow to build confidence. It’s becoming more common to see this as a line item in contracts (Contract Data Requirements List or CDRL)

Subsequent steps in Production & Deployment are:

  • Low rate initial production (LRIP)
  • Full rate production (FRP)

 

Who the customer is: Mechanics on the factory floor using hololens for work instructions, saw a lot of interest at Raytheon and NG to use Virtual Work instructions overlayed onto the hardware (Google Glass, Light Guide Systems, etc). In a more mature program that’s in production, the mechanic, or the electrician on the factory floor would be the end user. Today, they look away from the product where work instructions are pulled up on the computer. Their instructions might be several feet away from the work, hopefully they’ve interpreted the instructions well so they don’t cause a defect. Operators work from memory or don’t follow work instructions if it’s too cumbersome to do so. DCMA (Customer’s oversight) issues corrective action requests (CAR’s) to the contractor when operators don’t appear to be following work instructions (i.e. the page they’re on doesn’t match the step in the process they’re currently working on, or worse, they don’t have the instructions pulled up). Getting too many of these is really bad. So where AR is really useful, is when AR is overlaying instructions on the product as it’s built. Care should be given to the Manufacturing Engineer’s workflow for creating and approving work instructions, work instruction revisions, etc. Long-term, consideration probably needs to be given to integration with the Manufacturing execution system (MES) and possibly many other systems (ERP, PLM, etc.).

The Hololens tech is seemingly a ways away from that––seamlessly identifying the hardware regardless of physical position/orientation as well as making it easy for manufacturing engineers to author compliant work instructions

Another consideration, for any of the above use cases in the defense industry, is wireless. Most facilities will not accommodate devices that transmit or receive signals over any form of wireless. For the last use case, tethering a mechanic to a wired AR device is inhibiting.

 

by dshah1120

Acceleration and Motion Sickness in the Context of Virtual Reality (VR)

As I traveled around the world with the HTC Vive and Oculus Rift, universally first-timers would be fascinated, but a bit woozy after trying VR. What contributes to this? One possibility is the vergence-accommodation issue with current displays. However, the subject of this post is locomotion and the anatomical reasoning behind the discomfort arising from poorly designed VR.

With VR you typically occupy a larger virtual space than that of your immediate physical surroundings.

So, to help you traverse, locomotion or in other words a way of sending you from point A to point B in the virtual space was designed. Here’s what this looks like:

Image result for teleportation vr gif

Caption: This guy is switching his virtual location by pointing a laser on the tip of his controller to move around.

Movement with changing velocity through a virtual environment can contribute to this overall feeling of being in a daze.

That’s why most creators smooth transitions and avoid this kind of motion (i.e. blink teleport, constant velocity movement from Land’s End). Notice how the movement seems steady and controlled below?

Image result for lands end vr gif

Acceleration and Velocity

‘Acceleration’ is, put simply, any kind of change of speed measured over time, generally [written] as m^-2 (meters per second, per second) if it’s linear or in rad^-2 (same but with an angle) if it’s around an axis. Any type of continuous change in the speed of an object will induce a non-zero acceleration.”

The Human Vestibular System

When you change speed, your vestibular system should register an acceleration. The vestibular system is part of your inner ear. It’s basically the thing that tells your brain if your head is up or down, and permit[s] you to [stand] and walk without falling all the time!

Internal ear diagram that show the semi-circular cannals where the acceleartion forces are sensed.

Fluid moving in your semicircular canals is measured and the information is communicated to your brain by the cranial nerves. You can think of this as [similar to how] an accelerometer and a gyroscope works.

[This] acceleration not only includes linear acceleration (from translation in 3D space), but also rotational acceleration, which induces angular acceleration, and empirically, it seems to be the worse kind in the matter of VR sickness…”

Now that you have this grounding for our anatomical system of perceiving acceleration the upshot is that often viewers in VR will experience movement visually but not via these semicircular canals. It’s this incongruence that drives VR sickness with current systems.

Some keywords to explore more if you’re interested in the papers available are: Vection, Galvanic Vestibular Stimulation (GVS), and Self-motion.

via Read more on the ways developers reduce discomfort from the author’s website.