We made a lot of progress on a totally head mounted version. While these Sharp IR distance sensors were easy to work with and we had them on hand, there is better technology available.  

In the past few years, the technology to measure how fast light travels  (the Time of Flight, ToF)  distancesas short as 1 millimeter to as long as 2 meters has become available in a tiny package.  

Considering that light travels the length of a standard piece of notebook paper in one cycle of a gigahertz clock, that is kind of amazing. This technology is a form of LIDAR (Light Detection and Ranging). Think radar with lasers.  

The photo below shows five breakout boards from Adafruit each with a VL53L0X ToF sensor made be  ST.

Five tiny prototyping boards from Schmartboard with the DRV2606L motor drivers. 

The motor driver boards attached to another Schmartboard holding an I2C multiplexer which is, in turn, connected to an Teensy LC.

Both parts ready to be connected together.