Automated Drink MachinePage 1
Automated Drink MachineProject Final Report
Michelle Advena
Alex Horejs
Jefferson Medel
Connor Petilli
12/15/2015
The Automated Drink Machine is a system that makes mixed drinks.
Contents
I. Overview
Needs Statement
Objective Statement
Description
Marketing Diagram
II. Requirements specification
Needs
Analysis to justify specifications
Drink Platform Subsystem
Control System
III. Concept selection
Survey of Existing Systems
The Inebriator
Coca-Cola Freestyle
Bartendro 15
Concepts Considered and Chosen
Rationale
Survey of Dispensing Methods
Optics
Actuators
Peristaltic Pumps
Solenoid Valves
Pressurized Air
Methods Chosen and Rationale
Drink Platform Systems Considered and Chosen with Rationales
Survey of Possible Platforms
Platform 1 - Driven directly by a motor
Platform 2 - Driven by a motor through gears
Survey of Possible Motors
DC motor
Servo motor
Stepper motor
Survey of Possible Sensors
Photo cell
Break beam sensor
Systems Considered and Chosen
Cup Dispenser Systems Considered and Chosen with Rationales
Survey of Possible Sensors
Survey of Possible Motors
Control Systems Considered and Chosen with Rationales
IV. Design
System Diagram
Subsystems
Alcohol Dispensing
Mixer Dispensing
Drink Platform
Control System
User Interface and Control
Engineering Standards
Multidisciplinary Aspects
Mechanical Engineering
Computer Engineering
Electrical Engineering
Computer Science and Networking
Background
Outside Contributors
V. Constraints and Considerations
Extensibility
Manufacturability
Reliability
Economic Context
Health and Safety Issues
Societal Context
Sustainability
Ethical
VI. Costs
VII. Testing
Drink Platform Subsystem
Component Testing
Control System
VIII. Risks
Subsystem Risk Assessments
Platform Subsystem Design
Control System Communication
Additional Risk Assessments
IX. Milestone Charts
X. Critical Evaluation
I. Overview
Needs Statement
When entertaining groups of people, there are two major options for serving beverages to guests: hiring someone or employing a self-serve method. Hiring a professional server would involve a significant expense on the part of the host and is not really feasible for small, personal events. Though because the host is hiring a professional, it does offer a certain degree of quality control. Self-serve methods often include single-serve containers or having guests pour themselves drinks from a selection. A system is needed to dispense mixed drinks efficiently and accurately without the disorder of open self-serve containers, the inconvenience of measuring out liquids, or the cost of hiring a third party.
Objective Statement
The objective of this project is to design and prototype a system that will allow guests to order any existing or mixed drink without having to wait in a queue, allowing them to enjoy the event free from distraction and prevent them from distracting the other guests. The system will be controllable remotely. Guests will be able to queue pre-existing or custom ordered drinks for dispensing and proceed to the dispenser to retrieve the drinks when notified. Social media functions such as posting to a Facebook timeline or tweeting from Twitter will also be available to provide ways for the guests to enhance their experience.
Description
The Automated Drink Machine (ADM) dispenses measured amounts of liquids to create mixed drinks. Food-safe materials are be used for all parts involving the storage and dispensing of liquid ingredients. Motion controllers and sensors inform the controller as to the status of the platform holding the cups and drinks. There are six dispensers and every dispenser corresponds to a different liquid. The ADM is controlled via a command line interface. When turned on, the ADM centers the platform and displays a menu, giving the user several options. These options include dispensing single shots, dispensing a drink from a database, and adding a new drink to the database, Once the user selects an option, the ADM will wait for a cup to be placed on the platform, upon which it begins executing the selected option. Reaching for a drink while the platform is in motion will trigger a response from the IR break beam sensors, and stop the platform .
Marketing Diagram
A preliminary digital, 3-D sketch of system chassis can be seen below. The chassis will have the drinks, hoses, and various dispensers mounted to it to create the device.
Figure 1: Preliminary Marketing Diagram
II. Requirements specification
Needs
Table 1 below enumerates the customer’s needs.
Table 1: Customer Needs
No. / Description1 / The system shall provide a simplistic method for changing drinks/containers.
2 / The system shall correctly dispense a measured amount of fluid.
3 / The system will allow cups to move to their proper location.
4 / The system will detect when a cup is placed on the platform.
5 / The system will detect when a user is reaching for the cup.
6 / The system will protect its components from spills.
7 / The platform will move smoothly to prevent the liquid in cups from spilling.
8 / The operation of the system shall not be noisy.
9 / The dispensing system shall be able to function without manual user intervention.
10 / The user will be notified when he or she needs to refill the cup dispenser
11 / The cup dispenser will drop a new cup whenever a new drink is ordered
12 / The dispensed drink shall be safe to drink.
13 / The system will be able to be controlled remotely.
14 / The system can be controlled from various mobile platforms.
15 / Multiple clients can use the system at once
16 / The system will allow preset drinks to be ordered
17 / The system will allow custom drinks to be ordered
18 / The system will allow multiple drink orders to be queued
19 / The system will allow monitoring of a drink orders status
20 / The system status shall be monitored by an elevated client.
21 / The system shall provide a list of preset drinks available to the client.
22 / The system shall allow the list of preset drinks to be modified by an elevated client
23 / The system shall provide social media features.
(Posting to Facebook timeline, Tweeting from Twitter)
24 / The system shall allow for multiple levels of verified clients.
(provide access to system functions, alcoholic content)
Engineering Specifications
The table below enumerates the engineering specifications and the corresponding customer need(s).
Table 2: Engineering Specifications
No. / Description / Need(s)A / The software handling drink orders will have the ability to queue drinks. / 18
B / The device handling drink orders will not need to be connected physically to the dispensing unit. / 13
C / The user shall be able to add and remove drinks manually from the machine via a provided container. / 3
D / A standardized interface/container will be used to store liquids. / 1
E / Cups will be easily replaceable. / 1
F / Machine will notify user when cups need to be replaced. / 10
G / The platform will be divided into uniquely coded sectors, one for every cup that the platform can hold. / 3
H / The platform will have slots with sensors where a cup will be placed. / 3, 4
I / The system will utilize sensors to detect when a user is reaching for a cup. / 5
J / Relevant portions of the platform will be watertight and waterproof to at least one full dispensed cup of water / 6, 7
K / The platform will be rotated by a low RPM motor / 8, 3
L / Ability to measure and dispense a set amount of alcohol in a multiple of 35mL. / 2
M / Ability to measure and dispense a specified amount of a mixer (e.g, ½ cup or ¾ cup) / 2
N / Noise from normal operation will not exceed 60 dB. / 8
O / All valves, levers, etc. will be electronically (or electro-mechanically) operable. / 9
P / The cup dispenser will be replenished by feed / 1
Q / The cup dispenser will have a sensor that will detect the presence of the bottom cup / 10
R / Food-grade parts will be used for all components coming into contact with the liquids. / 12
S / The system will include a wireless network adapter. / 13
T / A web-based user interface will be provided. / 19, 14
U / The system shall provide user creation and authentication via a user database / 24
V / All client actions will be available in the web-based user interface / 16, 17, 18, 19, 21, 22
W / Elevated client actions will be available to authenticated clients (e.g, modifying drink queue, system power, etc.) / 20, 22
X / The system will allow multiple network connected clients. / 15, 18
Y / The system will maintain a database of preset drinks. / 16, 21, 22
Z / The drink database shall be modifiable by authenticated clients. / 22, 24
AA / The system will interface with social media APIs. (Facebook, Twitter) / 23
AB / The web-based interface will allow multiple concurrent connections. / 15
Analysis to justify specifications
Drink Platform Subsystem
The platform is circular to make it as compact as possible. Any other shape would cause gaps and unused space when rotating it. The moving platform holds cups which contain liquid inside of them, so the motor driving it moves at a slower and smoother rate. Sensors are the best way to detect if something is moving or in place. Sensors are mounted in grooves on the bottom of the platform so as to be less obtrusive. The grooves also make sure that the cups stay in place while the platform moves. The platform is divided into color-coded sectors to allow the Automated Drink Machine to easily convey where a user’s drink is located, and by extension, which drink is theirs since there is only once sup per sector. Lastly, the platform is waterproof and watertight to ensure that the components used in the system are not damaged in the case of accidental spills.
Control System
To provide a way for multiple clients to connect from multiple different platforms, the system will need to have an adapter for a multi-client wireless protocol. Considering the necessity of cross-platform support, the wireless protocol must further provide a unified form of communication on multiple platforms. A web-based interface provides both a method of multiple clients and cross-platform support assuming certain resources like an existing wireless network are available. Utilizing an existing wireless network, the system can connect and provide a web-service to other users on the network. Not only does this allow multiple wireless clients, but also a simple avenue for cross-platform support via existing web-based software concepts.
The system must also have a database of drinks to satisfy the need for a client to view, modify, and select pre-set and custom drinks. An additional user database is also necessary to allow users to not only be created and authenticated, but also remembered for future events with the ADM to avoid recreating a user every time.
To specifically provide aspects of social media like custom drink sharing, the software must have access to high level social media APIs. Most users are likely to be familiar with and regular users of existing social media services. As such, to provide a way to access and share on these platforms immediately, the inclusion of standard social media service functions can be achieve with existing APIs
III. Concept selection
Survey of Existing Systems
The Inebriator
Website:
One of the most popular drink mixers online with a large amount of information available via blog, the Inebriator was designed to mix alcoholic drinks at parties for attendees who do not have the inclination to mix their own drinks. It eliminates the need to look up and measure ingredients and produces repeatable results. Drink selection is made via an attached console with a rotary encoder. Drink dispensing is managed by an Arduino Mega 2560, while a Fez Panda II manages the drink selection console. Drink recipes are stored on a SD card in XML format. In addition to its ability to measure and dispense precise quantities of alcohol, the Inebriator dispenses drink mixers (e.g. orange juice) and uses a pressurized air tank to push the liquid through the tubes. RFID is used for to authenticate admin access.
Coca-Cola Freestyle
Website:
The most widely seen, commercially-available, custom drink maker, the Coke Freestyle is a soda fountain that allows users to mix a variety of beverage bases, (e.g., Coke, Diet Coke, water), with different flavors, (e.g., vanilla, cherry, lime), to form a customized drink. Micro-dosing technology is employed in dispensing the flavors, allowing them to be packaged in small cartridges. Drink selection is made via a touchscreen interface.
Bartendro 15
Website:
The Bartendro 15 is a high-end automated cocktail mixer with a base cost of $3,700. The system employs 15 peristaltic pumps to dispense accurate and repeatable cocktails. Controlled via smartphone, users can create custom create drinks, modify existing ones, or add new ingredients. Precision is emphasized in the setup with dispensing accurate to a ½ oz. When fully assembled, it is 36”x 24”x 12” and marketed for both home and business.
Concepts Considered and Chosen
The table below provides a comparison of features found in currently available systems as well as the features to be included in the designed system, where a check mark (✓) indicates the presence of a feature. The table focuses on the Inebriator and the Coca-Cola Freestyle, as these represent the private and commercially-available systems, respectively, most closely aligned with the project’s initial concept.
Table 3: System Comparison Chart
Feature / The Inebriator / Coke Freestyle / Planned(this project)
Drink queue / ✓
Drink database / ✓ / ✓
Custom mix (real-time) / ✓ / ✓
Drink selection automatically updates based on availability / ✓ / unknown / ✓
Cooling system / ice dispenser (manual fill)
Carbonation system / ✓
Drink Platform / mobile,
linear / stationary / mobile, rotational
Remote ordering / ✓
Cup detection/sensing / ✓ / ✓
Precise volume measurement / ✓ / ✓
Push-and-hold to dispense / ✓
Self-cleaning / ✓
Phone app / ✓ / ✓
Touch interface / ✓ / ✓
Low/empty level detection / ✓ / ✓
Rationale
The Automated Drink Machine (ADM) attempts to strike a balance between the user-friendly, polished appeal of the Coke Freestyle and the powerful features of a custom system like the Inebriator. To achieve this balance, a mobile interface with a user-friendly presentation was selected. To focus efforts on the mobile interface, an at-machine interface is not provided. Additionally, to facilitate the use of custom drinks, a dynamic drink database is used to allow for the most accurate drink creation and selection. With this system, the user does not have to worry about drinks that have been emptied or removed and are no longer available. These drinks then become available again immediately upon restocking and updating the database.
To achieve the queue system as described, the specific method of implementation will be a rotating drink platform. The queueing system allows for the remote ordering system to work correctly. Without queueing, operation is effectively no different from normal at-machine ordering. With queuing and the rotating platform however, one can order a drink and have it begin preparation immediately, rather than after the guest in from of them has ordered.
Survey of Dispensing Methods
Optics
Despite what the name implies, an “optic” (also known as a “non-drip measure”) has nothing to do with light. Instead, it is the British term used to describe a device that attaches to the top of a bottle of alcohol and, when inverted, dispenses a measured amount (e.g. 25 mL) of the spirit. The beauty of these is that they are simple to operate – all that needs to be done to dispense the liquid is press the lever, as the system is gravity-fed. This could easily be achieved with some a linear actuator. One drawback of this system is that brackets to hold the optic and the attached bottle need to be either bought (ideally from the same company that manufactures the optics) or made. Table 4 shows summarizing prices from the well-known UK optics manufacturer Beaumont. All optics listed in the table can be operated with a single hand, or in this case using a linear. actuator.
Table 4: Prices for Beaumont Optics
Product / Price Per Unit* / USD Approximate25 mL Vogue / £8.50 / $12.65
25 mL Metrix SL / £7.00 / $10.42
25 mL Solo Professional / £5.18 / $7.71
Shelf Bracket / £3.20 / $4.71
Wall Bracket / £2.44 / $3.59
*At this time it is unknown if minimum purchase is 1 carton (100 units) or 1 unit.
Actuators
To determine the specifications needed for the actuator, more data on the optic is required. The main unknown is the amount of force required to operate the optic. This will drive the base cost of the actuator, as an increase in force corresponds to an increase in torque.
Peristaltic Pumps
Peristaltic pumps are ideal from a contamination standpoint in that no mechanical parts come into contact with the fluid being moved. Therefore, the only thing that ever needs to be sterilized is the inside of the tubing. However, this does mean that the tubing needs to be periodically replaced due to wear. Another potential drawback is that the pump does not provide a constant flow.
Tubing can be chosen such that it meets any specific requirements for the fluids being pumped, such as food-safe or compatible with aggressive fluids. For example, McMaster-Carr manufactures food-safe tubing specifically for peristaltic pumps, “High-Purity White Silicone Rubber Tubing for Peristaltic Pumps.”
From a “mixers” point of view, peristaltic pumps are ideal in that they can easily move more viscous fluids. They also provide an easy way to measure the amount dispensed, if sensors to detect fractions of a rotation are added.
The makers of Bartendro sell the custom peristaltic pump they use (it contains additional hardware and software), as well as provide free schematics under the Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0) license. Pricing for their dispenser starts at $120. When the fact that many peristaltic pumps are priced at over $100 is taken into consideration, the cost doesn’t seem as high.
Solenoid Valves
Solenoid valves could be used either individually or as sets of two. If used individually, solenoid valves could be used as an on/off switch in a gravity-fed system. In sets of two, the valves could be used similarly to an optic. Connected by tubing (where the volume between the two valves is equal to a specified amount, e.g. 25 mL), the top valve would open to allow liquid into the chamber. Once full, the top valve would close and the bottom valve would open, allowing the liquid to then flow into the drink. The advantage to using the valves over optics is that it can be programmed such that the chamber between the valves is only ever filled when a drink is about to be poured. The downside to that method is that there will be additional wait time while the chamber fills.