Milk Stocking Machine

This robot autonomously stocks dairy fridges at the supermarket. Once you pull out a carton, the system detects that milk has been removed, and the gantry system restocks the shelf.

What

The dairy fridges at the grocery store are a high-traffic area, and our local grocery store always has empty shelves. We addressed this problem by designing a system that mounts to the stocking-side of a dairy fridge and can pick up cartons of milk from the pallet, then deposit them onto the appropriate shelf. The system is activated every time a customer removes a carton of milk from the shelf, so they’re always stocked.

How

Gantry System

Sensors Installed

Carton Carrier

Our machine has four subsystems: the Gantry, the Carton Carrier, the Inventory Tracking system, and the Rollers.

  • Gantry: Translates the milk across the back of the fridge.

    • The vertical gantry utilizes four steel rods as linear rails and is driven by stepper motors and a timing pulley.

    • The horizontal gantry is driven by a stepper motor connected to a lead screw.

    • Both components use limit switches for position finding and the whole system is controlled by a CNC shield expansion board.

  • Carton Carrier: Interacts directly with the milk cartons. The bottom holds a conveyor belt driven by a stepper motor and is controlled using the spindle output on the CNC shield.

  • Inventory Tracking: Utilizes pressure sensors at the front of each shelf. Every time a change is detected by the sensors, the system is activated and moves to restock the shelf. This subsystem was controlled by an Arduino Mega.

  • Rollers: Allows the milk to slide down the shelf for customers to reach. We used 3D printed cylinders threaded onto wooden dowels along each shelf.

Rollers & Shelves

Results

Roller Assembly Drawing

Carton Carrier Assembly Drawing

  • We developed a prototype “milk fridge” to mount the Milk Stocking Machine using tools and materials from UT’s Woodshop.

  • Created a full CAD model and engineering drawings of each subsystem and the full assembly

  • Gained real-world experience taking interviews and performing market research for our target group and developed a functional solution to the problems they were facing.

Final Presentation Clip