COFFEE VENDING MACHINE

Design of coffee vending machine



Table of Contents

DESIGN OF COFFEE VENDING MACHINE3

Abstract3

Introduction3

System Design4

General Specification4

Functionality4

Safety4

Subsystem Design5

Recognition of coin5

Conceptual Design6

Coin Detection6

Coin Recognition6

Process Detail6

Refunding the Change9

Conceptual Design9

Process Detail9

Grinder Control10

Conceptual Design10

Process Detail10

Heater Control11

Conceptual Design11

Process Detail:12

Cup detection12

Conceptual design12

Process Detail13

Process of Coffee Dispensing13

Conceptual Design14

Process Detail14

HMI (Human Machine Interface)16

Conceptual Design17

Process Detail17

Conclusion20

References22

Appendix24

DESIGN OF COFFEE VENDING MACHINE

Abstract

As a student of Napier University after the Masters program in Mechatronics have to make assessments as part of the Engineering Control module.

This assessment task is to design an automatic coffee dispensing machine for use on campus. The coffee machine is designed completely by the techniques of mechatronics. This process involves the recognition of the coin, the grinder control, heating control, flow control and making coffee. And this report includes the detailed design process and the description of the parts used in the design process of the coffee machine.

Introduction

The course is to design a coffee vending machine using a mechatronic design methodology. The machine will be used on a college campus. The customer can choose between the choice of latte, cappuccino and coffee with ingredients such as with or without sugar.

This vending machine design requires a synergistic integration in different fields. Mechatronics methodology approach was followed, in order to achieve the desired objectives in an appropriate manner. This system has been divided into several subsystems which are explained in the section number, such as conceptual design and detailed design is explained also give reasons for signal conditioning, the actuator mechanism and the measuring system options.

System Design

The objective of this machine is to prepare hot drinks for the customer. A HMI is used to select the drink by the customer. The tasks involved in the process are controlled by a PLC. The software commands all the actions and make alert if any problem occurred in the system problem. The coffee dispensing machine covers the user requirement which includes the General Specifications of the machine, its functionality and safety during its operation (Talbot, 2004, pp 123).

General Specification

The dimension of the machine is 750 X 750 X 750 mm. Because of this, the communication between the user and machine is easy. It also requires a low cost to maintain the machine so it is very cost effective.

Functionality

The coffee machine offers the choice of latte, cappuccino and espresso with or without sugar according to user requirement. It accepts only two kind of cups, large size cup for latte and cappuccino and small size cup for espresso. The coffee machine accepts only £0.50 p, £1 and £2 coins and returns the change automatically as the rate of coffee is only £1.50p.the total response time of the machine to prepare the required coffee will be 30 seconds.

Safety

The coffee machine has IEC62061 (Safety of machinery, Functional safety of safety related electrical, electronic and programmable electronic control systems).When the dispensing machine is open to refill or technical repair, the safety micro switch will open the whole circuit. The water boiler will be covered by thermal isolator in order to avoid burning with hot surface when contact ...