The possibilities are endliess when you add to the budget .
i'll try and jot down my thoughts, and I'll modify this when I come up with new ones.
1.) Get a fancy LIDAR based system , supplemented by a camera to do the same thing ., and also change the pitch and timbre with colour and shape. ( Done by the team at Berkeley )... But the challenge is to get to the commercial scale.
2.) Ultrasound and fabrics don't mix. Hence, Project Batyeye is pretty much useless around fabrics right now . ( The fabric will absorb the waves , so , no reflection = no sensor data ) . If you're using it in rural India or somewhere in africa , you don't really find curtains or drapes around very often . So , solving this problem wasn't really the bid priority in the first prototype/. Addition of a second sensor ( IR ) for when the ultrasonic sensor goes out of range. ------> That brings up another problem , black objects outdoor. They won't get detected. So pretty much black fabrics will be the achilles heel of this device.
I will try and add as much as possible as I remember ....