Canes, Redux

This page discusses various designs for navigation aids, packaged as handles (or replacements) for the traditional "white cane".

Introduction

I like the idea of equipping a cane handle with assorted sensors (etc) and allowing it to communicate via Bluetooth. As the user sweeps the cane back and forth, a wealth of data could be collected and sent to (say) a smartphone for local processing, integration with server data, etc.

Multi-modal Sensors

I'd like to add a multi-modal sensor such as Adafruit's 10-DOF "inertial measurement unit". This provides barometric pressure/altitude, temperature, and three axes of accelerometer, gyroscopic, and magnetic (compass) data. This kind of information could be used to calculate the positions of the cane over time.

Ultrasonic Sensors

High-quality ultrasonic sensors are also a basic requirement. The MaxBotix MB1360 is a computer-friendly sensor which I'm using in the Robotic Explorer. It provides amplitude and distance information for multiple objects, with one centimeter precision up to its 10 meter range. This kind of information would work well for building up a model of the user's surroundings.

However, I also like the kind of biomimetic (and human-friendly!) output produced by The Sonic Eye, which allows the user to recognize acoustic signatures of various objects. Basically, this device:

  • emits a rising-frequency chirp
  • captures the reflections in stereo
  • slows down the captured reflections
  • plays them into the user's ears

The MB1360 doesn't support this use case, but some compromise might be possible. For example, it might be possible to create a sensor which supports both modes. Alternatively, it might be possible to map a calculated 3D model into a synthetic stereo pair of "reflected" signals.

Current Offerings

UltraCane

The UltraCane is modeled on the traditional long white cane, but the difference is in the electronic handle, which works by emitting ultrasonic waves to locate obstacles in the user's vicinity. This includes objects at shoulder/head height, for example, wing mirrors on vans and Lorries, overhanging tree branches etc.

It gives tactile feedback to the user through two vibrating buttons, which have been ergonomically positioned on the handle. The two buttons, when vibrating, indicate the direction of the obstacle; the frequency of the vibration lets the user know the proximity of the obstacle. This type of feedback stimulates a spatial 'mind map' in the brain, enabling the user to obtain information about the layout of their immediate environment and surroundings. Essentially, using the UltraCane offers a protective hazard 'envelope' around the user.

-- Aspire Consultancy UltraCane

The UltraCane has a lot of promising characteristics, beginning with the fact that it is a shipping product. I like the fact that it has two sensors, allowing it to cover a vertical range of angles in front of the user.

VAVI

Roman Kozak's "Byte-sized Bio" says: "Student by day. Entrepreneur by night. Designer of electronics and code." Basically, he's a young, energetic inventor with some great ideas. In particular, his VAVI (Virtual Aid for the Visually Impaired) is tantalizingly close to the kind of thing I'd like to see someone make.

That said, I'm not convinced that eliminating the physical cane is a great idea for all users. The physical cane provides a great deal of tactile feedback which the virtual cane might not (or at least in the same format). Also, the "white cane" is very recognizable to the sighted public, so it alerts them to be careful in the presence of a blind person. All told, I'd like to see the unit equipped to handle an optional cane.

Resources


This wiki page is maintained by Rich Morin, an independent consultant specializing in software design, development, and documentation. Please feel free to email comments, inquiries, suggestions, etc!

Topic revision: r92 - 22 Jan 2016, RichMorin
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