AutoBill - AI Powered Instant Checkout
Introduction: AutoBill - AI Powered Instant Checkout
AutoBill is an AI-powered autonomous checkout system for retail stores, that combines the power of computer vision and machine learning to provide an amazing shopping experience. AutoBill provides a faster checkout shopping experience to minimize human interactions in the store to keep shoppers and employees safer during the pandemic. AutoBill uses computer vision and machine learning to visually detect and instantly identify the items placed and the weight sensor measure the weights of the things placed on the counter-top. Once the items are identified, things are automatically added to the cart and the bill is generated instantaneously. QR code for payment is generated and users can pay the bill by scanning the QR code.
Step 1: Electronic Components
These are the major electronic components required for building this project. Raspberry Pi 3B is the brain of this device. Here is a list including links to where you can find them.
* 1 X Raspberry Pi 3B
* 1 X Weight Sensor (Load Cell) 0-3kg
* 1 X HX711 Load Cell Amplifier breakout
* 1 X WS2812B RGB Led strip
* 1 X REES52 5 Megapixel 160° degrees Wide Angle Fish-Eye Camera
* 1 X 5V 2A power supply
Step 2: Preparing Wood
For making the cabinetry of the system, we have used 15mm thick plywood sheets. We have Cut it down with a circular saw as per the above dimensions.
Sanding is done to create an even surface and enhance the look of wood. It can take time to do a good job of sanding, but every project benefits from sanding. So we are started with fine grits and endeded with very fine grits.
Step 3: Making Necessary Holes
We need to attach the load cell to the center of the base. For this, we marked the positions accordingly and drilled three holes, two of them connecting the load cell and the other for taking out connections from the load cell. Also, we made a thin slit for taking the led connections wires and camera cable to the Raspberry Pi by drilling consecutive three holes.
Step 4: Cabinetting
For making the cabinet, we connected all the plywood parts using normal wood screws. Old layers of paint are are still visible in the cabinet, so let's cover them up with some new paints.
Step 5: Painting Cabinets
Firstly we primed the surfaces with two coats of normal wood primer sanding well between each coat. A primer preps the painting surface and seals any stains so that the paint adheres well, and you'll get the smoothest, cleanest finish possible.
Finally, we applied white satin finish paint for getting an elegant look for the cabinet. 267
Also, we attached four bushes to the cabinet.
Step 6: Weight Sensor(Load Cell)
Here we use the Load cell to measure the weight of the objects. The load cell is a sensor or a transducer that converts a load or force acting on it into an electronic signal. This electronic signal can be a voltage change, current change, or frequency change depending on the type of load cell and circuitry used. There are many different kinds of load cells.
The load cell we are using is a Resistive one. Resistive load cells work on the principle of piezo-resistivity. When a load/force/stress is applied to the sensor, it changes its resistance. This change in resistance leads to a change in output voltage when an input voltage is applied. The resistive load cell is made by using an elastic member (with a very highly repeatable deflection pattern) to which a number of strain gauges are attached.
Here we are using a load cell which is having four strain gauges that are bonded to the upper and lower surfaces of the load cell. When the load is applied to the body of a resistive load cell, as shown above, the elastic member, deflects as shown and creates a strain at those locations due to the stress applied. As a result, two of the strain gauges are in compression, whereas the other two are in tension.
During a measurement, the weight acts on the load cell’s metal spring element and causeselastic deformation. This strain (positive or negative) is converted into an electrical signal by a strain gauge (SG) installed on the spring element. The simplest type of load cell is a bending beam with a strain gauge. We use the Wheatstone bridge circuit to convert this change in strain/resistance into a voltage that is proportional to the load.
The four strain gauges are configured in a Wheatstone Bridge configuration with four separate resistors connected as shown in what is called a Wheatstone Bridge Network. An excitation voltage – usually 5V is applied to one set of corners and the voltage difference is measured between the other two corners. 552