Supermarket Navigation Assistant System

Background:

For people with visual Impairments going around supermarkets is a hard task it's hard for them to know which aisle they are currently in and which items is sold in this aisle. This solution is about to empower people with visual Impairments by giving them information about their location within the supermarket.

Solution:

Indoor Navigation system that detect the user location and output audio with information about the current Aisle, like Aisle number and the items found in this Aisle.

How the Solution Work:

The solution can be divided into two parts, Location Detection and Audio Generation.

Location Detection:

The System uses the Accelerometer data from IMU to detect the horizontal displacement, which can can be translated to a location within a map. For example the following image shows the map we used to detect the location within.

For the provided map the Horizontal Displacement in the Y direction would be enough to know which aisle we are currently in, but for more complex (asymmetric) maps both x and y displacement would be required.

DesignDrawback:

Depending on the IMU data only to detect the location increases the error rate because of many reasons, for example :

• Accumulated integration error : Convert the Accelerometer data into displacement is done by integrating the the acceleration read from the sensor twice (to speed then to displacement).
• Bad IMU Accuracy : Cheap IMU doesn't provide high accurate data and require calibration every time.

Howtoovercomedrawback:

Instead of depending only on the IMU sensor we are going to use another senor to detect the location and we are going to fusion the data from the two sensor in order to get accurate location. The second location detection strategy would be done based on WiFi RSSI. This part wasn't implement in the solution yet

Audio Generation:

The Audio is generated from the STM32F407-Disc, the board would receive the detected Aisle number and would play the corresponding wav track that contains information about the detect aisle.

In the current implementation all the audio data (wav files) are stored in the internal flash of the microcontroller, but in the future these data would be stored in external memory (SD Card or NAND Flash) as the internal Memory won't be enough to store more and more data.