Tango take the Wheel

Johnny Lee, my boss a couple links up, recently showed off at Google I/O a reel of recent research improvements on Tango. Possibly not as exciting as the other stuff in the video, but at the 1:19 mark in the video you’ll see some research by me and my coworkers to see how well Tango works on a car. As you can see it works really well and we even drove it 8 km in downtown San Francisco through tourist infested areas. Surprisingly or not, the mass number of people or the sun didn’t manage to blind out our tracking.

How did we do it? Well we took Tango phone and quick clamped it to my car. Seriously. Here’s a picture of a Lenovo Phab 2 Pro and a Asus Zenphone AR attach to my car and me in my driving glasses. We ran the current release of Tango and did motion tracking only and it just worked! … As long as you shut off the safeties that reset tracking once you exceed a certain velocity. Unfortunately you users outside of Google can’t access this ability as in a way these velocity restrictions are our own COCOM Limits.

Also, this is something really only achievable with the new commercial phones. The original Tango Development Kit didn’t include good IMU intrinsics calibration. The newly produced cellphones at the factory will solve for IMU scale, bias, and misalignment. At the end of each factory line, a worker places the phone in a robot for a calibration dance. Having this calibration is required for getting the low drift rates. Remember our IMUs are cheap 50 cent things and have a lot of wonkiness that the filter to needs to sort out.

I’m not Dead

However I’ve been really busy working with Google’s project Tango. I encourage you to watch the video if you haven’t already.

What is NASA doing with project Tango? Well currently there is a very vague article available here. However the plan is to apply Tango to the SPHERES project to perform visual navigation. Lately, I’ve been overwhelmed with trying to meet the schedule of 0-g testing and all the hoops there are with getting hardware and software onboard the ISS. This has left very little time to write, let alone sleep. In a few weeks NASA export control will have gone over our collected data and I’ll be able to share here.

In the short term, project Tango represent an amazing opportunity to perform local mapping. The current hardware has little application to the large-scale satellite mapping that I usually discuss. However I think the ideas present in project Tango will have application in low-cost UAV mapping. Something David Shean of U of W has been pursuing. In the more immediate term I think the Tango hardware would have application to scientists wanting to perform local surveys of a glacial wall, cave, or anything you can walk all over. It’s ability to export its observations as a 3D model makes it perfect for sharing with others and perform long-term temporal studies. Yes the 3D sensor won’t work outside, however stereo observations and post processing with things like Photoscan are still possible with the daylight imagery. Tango will then be reduced to providing an amazing 6-DOF measurement of where each picture was taken. If this sounds interesting to you, I encourage you to apply for a prototype device! I’d be interested in helping you tackle a scientific objective with project Tango.

This picture is of Mark and I dealing with our preflight jitters of being onboard the “Vomit Comet” while 0-g testing the space-rated version of Project Tango. This shares my current state of mind. Also, there aren’t enough pictures of my ugly mug on this blog. I’m the guy on the right.

I pretend to be a part of HET SPHERES

I do other things beside develop Ames Stereo Pipeline. I actually have to this month because my projects’ budgets are being used to pay for other developers. This is a good thing because it gets dug in developers like me out of the way for a while so that new ideas can come in. One of the projects I occasionally get to help out on is HET Spheres.

This is a picture of that robot. The orange thingy is the SPHERE robot designed by MIT. The blue puck is an air carriage so we can do frictionless testing in 1G. There have been 3 SPHERES robots onboard the ISS for quite some time now and they’ve been hugely successful. However we wanted to have an upgrade of the processing power available on the SPHERES. We also wanted better wireless networking, cameras, additional sensors, and a display to interact with the Astronauts. While our manager, lord, and savior Mark listed off all these requirements, we attentively played angry birds. That’s when it suddenly became clear that all we ever wanted was already available in our palms. We’ll use cellphones! So, though crude, we glued a cellphone to the SPHERE and called it a day.

Actually a lot more work happened then that and you can hear about that in Mark’s Google Tech Talk. I also wasn’t involved in any of that work. I tend to do other stuff that is SPHERES development related. But I spent all last week essentially auditing the console side code and the internal SPHERE GSP code. I remembered why I don’t like Java and Eclipse. (I have to type slower so Eclipse will autocomplete. :/) This all collimated into the following video of a test of having the SPHERE fly around a stuffed robot. We ran out of CO2 and our PD gains for orientation control are still out-of-whack, but it worked!