Pizza Assembly Production Line

"Bachelor's Graduation Project"

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Project Summary:

This bachelor's graduation project was the complete design, analysis, and simulation of an industrial machine to automate the pizza assembly process. The system was developed to solve key industry problems: long production times, inconsistent quality and hygiene, and high labor costs.

Our team designed the entire machine from the ground up using SolidWorks for 3D modeling and FEA simulation. The production line is fully automated by a Delta PLC , with all operations and order selections (e.g., pizza type and size ) managed via a custom HMI dashboard programmed in DopSoft. The system logic was built using both ladder logic and Sequential Function Charts (SFC).

Project Sub-systems:

The machine was designed as a series of modular stations:

Main Conveyor:

A central conveyor, using food-safe round belts (specifically chosen to allow fallen ingredients to pass through), transports the dough between stations. Its speed is governed by the longest stage (12s for sauce), allowing a theoretical capacity of 300 pizzas/hour.

Tomato Sauce Mechanism:

A hopper equipped with an "Anchor" style mixing blade (selected based on viscosity analysis of ketchup) feeds a food-grade pump. A solenoid valve on a linear-motion gantry dispenses the sauce.

Cheese & Olives:

Dedicated hoppers for cheese and olives use "Flex Tip Style Rotors" (driven by 60KTYZ motors ) to prevent material jamming. A small vibrating motor on the cheese hopper prevents clumping.

Multi-Topping Stations:

Two rotating tables hold 8 different ingredients (e.g., meat, chicken, corn). The tables are rotated by stepper motors (controlled via the PLC's code) and toppings are dispensed using spiral screw feeders. The optimal screw design ("tapered core and variable pitch" ) was selected based on DEM analysis to ensure even flow.

Pepperoni Slicing Mechanism:

A custom-designed 4-bar linkage mechanism automatically slices pepperoni from a loaded chunk ( weighted with a load to keep it pushing down).

Extra Photos of the mechanical design

Electrical systems:

Motion of the system is precisely controlled by a mix of motors: an AC motor with a speed controller for the main conveyor , stepper motors for the rotating topping tables , and various DC motors for linear actuators and dispensers. The entire system is wired to a central Delta PLC, which integrates signals from a wide array of sensors, including proximity sensors for pizza detection and load cells to monitor ingredient levels in the hoppers.

The diagrams in the photos below, show the different parts of the electrical wirings for the main power system as well as the inputs and outputs into and from the PLC. The PLC code handles all I/O, such as using the (DPLSY) high-speed output function to send precise pulse commands to the stepper motor drivers and reading inputs from sensors to advance the assembly line from one stage to the next.

Software (HMI)

The user interface is a custom, multi-screen HMI dashboard developed in DopSoft. From this screen, a user can select one of 8 pizza types. This selection triggers a specific SFC path, activating the correct combination of pumps, motors, and dispensers in the correct sequence.

Skills Demonstrated:

This section shows the skills I developed/improved working on this project.

Mechanical Design & CAD: Designing a complex, multi-component industrial machine from concept to full 3D assembly using SolidWorks.
Engineering Analysis (FEA): Using SolidWorks Simulation to perform Finite Element Analysis on the machine's frame, verifying design integrity and achieving a high Factor of Safety (7.7).
Industrial Automation & PLC: Architecting a complete production line, mapping all I/O, and programming a Delta PLC using ladder logic and Sequential Function Charts (SFC).
HMI Development: Designing and programming a multi-screen, user-friendly HMI dashboard using DopSoft for system control and order selection.
Machine Design & Kinematics: Engineering custom-purpose mechanisms, including a 4-bar linkage slicer and spiral screw feeders.
Component Sourcing & Integration: Selecting and integrating diverse components, including AC/DC/Stepper motors , sensors (proximity, limit switch) , pumps , and load cells.
System Simulation: Using specialized software like Autodesk Inventor for mechanical verification and VisiMix for fluid/mixing analysis in the sauce tank.