Getting acquainted with the haptic feedback

The Sunu Band is an electronic mobility aid that functions as either a ‘stand-alone’ mobility device or work as a compliment to the white cane or guide dog. Our mobility guide will teach you the basic techniques that will enable you to safely detect, navigate and avoid obstacles. Remember that the Sunu Band is intended to detect obstacles that are at the waist/torso, upper body and head level.

What is Echolocation

Certain animals like bats and dolphins are able to orient themselves and navigate their environments using sound. Echolocation is the ability to use sound and echoes that reflect off of matter in order to find the exact location of objects within an environment.  

Sunu Band enables you to navigate your surroundings with echolocation by combining sonar with precise vibratory feedback that you can feel on your wrist. Sunu Band uses a sonar transducer that is capable of emitting high frequency sound waves while detecting the reflected sound waves or echoes that bounce off of objects.

Sonar is Directional

Sunu Band is only capable of detecting the echoes (that reflect off of objects) from the same direction in which the ultrasound is emitted. In other words, think of Sunu Band as a flashlight that uses sound instead of light. Just like any flashlight, the direction in which you aim the sonar sensor is where you will be able to detect the presence of objects. The ultrasonic wave emitted from the sonar sensor travels away from the Sunu Band in the form of ‘cone’. Objects that are within the area of this cone will interact with the ultrasound and produce echoes.

Sonar Detection Area

The detection area is like the ‘field of view’ of the sonar sensor. Generally speaking, the Sunu Band’s sonar emits an ultrasound wave that propagates away from the sonar in the shape of a cone. The wider the cone or detection area, the more ‘sensitive’ it is to objects, even those that are in the periphery and as thin (1cm) such as wires, tree branches etc. The narrower the cone or detection area, the less ‘sensitive’ it is to objects in the periphery. 

Sonar Range & Modes

Sonar range is referred to as the maximum distance at which an object can be detected. Sunu Band uses distinct sonar modes which are optimal for certain environments:

  • Short range or Indoor mode – can detect objects up to 6 feet (2 meters) in distance. This mode has a narrow detection area making it optimal for navigating indoors or crowded spaces and identifying corners, gaps and thresholds. 
  • Long range or outdoor mode – can detect objects up to 16 feet (5.5 meters) in distance. This mode has a wide detection area and is optimal for navigating outdoor spaces and detecting thin objects like tree branches, bushes and wires.

Knowing what the haptic feedback means

Haptic feedback is the way in which we communicate information via vibration. The Sunu Band uses haptic vibrations to communicate proximity or distance – basically you feel pulses on your wrist that tell you how far or close you are to an obstacle. Sunu Band changes the frequency of the vibration pulses to provide you with a sense of how close an object is. Here is what happens to the vibration pulses when an object is detected and within range:

No vibration pulses: means that there are no obstacles being detected. This also means that there is a free path and you may continue walking.

Intermittent vibration pulses: means that the object being detected is sufficiently far away from you. You may continue approaching the obstacle or navigate your way around it.

Moderate vibration pulses: means that the object being detected is now closer to you. You may navigate your way around it or continue approaching with caution. 

Constant Vibrations: the object is now within your personal space.

Introductory Exercises

The following exercises are intended to help you become acquainted with the Sunu Band’s sonar detector and haptic vibration feedback. Specifically we’ll explore what happens when a nearby object is detected and the importance of aiming the sonar detector. We’ve designed these simple exercises that can be done by standing in place. 

We recommend that you work in a known area, free from obstructions and obstacles. Please insure that your Sunu Band is charged. We will assume that you know the basic operation of your Sunu Band as described in our Product Guide. Please select a hand in which to wear your Sunu Band for these exercises. 

Exercise 1: Detecting the presence of a nearby object

The goal of this exercise is to know how the vibration feedback feels when an object is nearby (less than 2 feet or 1 meter) from the sonar. 

Step 1: Press the NAVIGATE button to activate the sonar or obstacle detector. Next, swipe in on the touchpad to switch to the indoor sonar mode

Step 2: Standing in place, please lower the hand in which you’re wearing the Sunu Band so that the palm of your hand is touching the front of your thigh. Doing this will fix the position of the sonar sensor in order to complete this exercise. You should not feel any vibrations at this time. If you are feeling vibrations or pulses, please readjust your position until they stop. 

Step 3: Now slowly raise your other hand (or the opposite hand to your Sunu Band) until you begin to feel the Sunu Band vibrate. What kind of vibrations do you feel? 

Step 4: Continue raising your hand and observe what happens to the vibrations from your Sunu Band. 

Please repeat steps 3 and 4 a couple of times. Observe when the Sunu Band begins to vibrate and when it stops vibrating. 

Conclusions: In this exercise, we kept the position of the sonar fixed because we placed our hand flat against the front of our thigh. At first, we did not feel any vibrations. That’s because there were no objects or obstacles that were within range and within the same direction of the sonar detector. 

Next, the Sunu Band provided constant vibration feedback as soon as an object/obstacle is nearby and in the same direction of the sonar. This happened while we raised our opposite hand. 

Finally, Sunu Band detects objects in real-time, as fast as a camera. You will notice that the Sunu Band will immediately vibrate as soon as your hand is in the way of the sonar sensor. And it will immediately stop vibrating as soon as your hand has cleared the path of the sonar detector. 

Exercise 2: Detecting the direction of a nearby object

The sonar sensor is only capable of detecting objects that are in it’s direction. In this exercise, we will explore how aiming the sonar sensor allows us to detect a nearby object that may be to our left, center or right. Aiming the sonar sensor allows you to orient yourself to the direction of an object or obstacle. You can do this exercise standing in place.

Step 1: Press the NAVIGATE button to activate the sonar or obstacle detector. Next, swipe in on the touchpad to switch to the indoor sonar mode

Step 2: Standing in place, lower the hand in which you’re wearing the Sunu Band so that the palm of your hand is touching the front of your thigh. You should not feel any vibrations at this time. If you are feeling vibrations or pulses, please readjust your position until they stop. 

Step 3: Slowly raise your opposite hand and hold it as soon as you feel constant vibrations. You hand is now in the path of the sonar detector. Please maintain you hand in this position for this exercise.

Step 4: Begin changing the direction of the sonar by slowly turning or rotating the wrist that’s wearing the Sunu Band. Try only to rotate the wrist without raising your arm.

Step 5: Continue rotating or turning your wrist until your palm faces forward. Notice what happens to the vibrations as you rotate or turn your wrist outward. At what point do the vibrations stop?

Step 6: Now rotate your wrist inward (in the opposite direction) until your palm is facing your thigh. Notice what happens to the vibration as soon as you rotate or turn your wrist inward. At what point do you feel the vibrations?

Conclusions: You aim the sonar sensor by rotating your wrist. This changes the direction that the sonar cone is aiming. The vibrations stop as soon as the object is no longer in the direction of the sonar sensor. When you rotate or turn your wrist, you are no longer aiming the sonar at your opposite hand.