Proposal
David Finnell, Eric Hawkins, Richard McManus, Mike Slusarczyk
Professor Mike Schafer
Senior Design I
28 November 2023
Final Proposal
Introduction
Our group aims to tackle the mildly infuriating problem of imperfect coffee making in the home. This proposal first aims to outline the prevalence of coffee consumption in the U.S., the current state of the at-home coffee maker market, and the issues that these existing machines present for consumers. From there, this proposal will describe our group’s proposed solution to this problem, the overall product we aim to design and build, the features that we look to present, the technologies that will be implemented to make this product possible, and the list of engineering milestones we will use to ensure our success.
This proposal serves as our theoretical approach to the problem at hand. Certainly, over the duration of the course, we expect to make modifications to the product’s design as we face obstacles. All of our design parameters are subject to change, but our core goal to create the perfect pour of coffee will remain.
Problem Description
Every day, 150 million people wake up to a cup of coffee (or two) in the United States, with about ⅔’s of them being brewed at home. That’s at least 100 million cups of coffee brewed at home every morning. But how many of these cups are brewed correctly? Take your standard Keurig coffee brewer. The machine offers three sizes; small, medium, and large. If you’re lucky, they might even give you exact sizes such as 8 oz, 12 oz, and 16 oz brews. However, as countless Keurig owners will tell you, those sizes are rarely correct. An 8oz brew today may be 6oz tomorrow. Why? Because these machines have no idea how much coffee they're actually dispensing! The buildup of debris inside the machine affects the pump's performance. The Keurig essentially guesses how much to pour based on the pump's estimated performance, resulting in the under-pouring, or worse, over-pouring of coffee.
Even if these machines did pour the correct amount (selecting 12 oz truly provides a 12 oz pour), custom pour sizes may still be desired. These days, people take their coffee on the go in insulated tumblers that are often much larger than even the 16 oz option on coffee makers: 20 oz, 32 oz, even 64 oz (just ask Richard)! With these large tumblers, people either have to leave the house with a half-filled cup of coffee, or spend time brewing multiple smaller batches risking overflowing their tumbler.
Proposed Solution
The solution that we propose is simple: a machine that brews the right size cup of coffee, everytime. Our solution aims to take the guesswork out of brewing coffee by simply knowing just how much to pour.
In order to make this possible, instead of pouring a predefined amount of coffee, the machine will be designed to pour coffee until it detects the mug or tumbler is full. That is, until the liquid in the cup is close to the rim. This may be achieved in a number of ways; however, one current embodiment of this machine is described below by the steps taken after placing a cup of choice on the brewer and initiating a pour.
- An eye-safe (Class I) laser sensor mounted on the body of the brewer will begin scanning the cup of choice from the side. Moving on a simple linear actuator, the laser will continue to move upwards and scan until it no longer detects the cup, indicating that the top of the cup has been found.
- Once the cup has been scanned for its height, the machine will begin the brewing cycle. Using the height detected, the machine will make an estimate for how much coffee needs to be brewed; a predefined function relating height and volume will be used.
- Then, the machine will begin pouring coffee into the cup. As the coffee is being poured, another laser mounted directly next to the dispensing nozzle will point downwards into the center cup. By using the height of the cup collected earlier and the proximity of the coffee to the downward facing laser, the machine will be able to detect how close the coffee is to filling the cup. The machine will automatically stop pouring once the poured liquid is a predefined distance from the rim (such as 1.25cm or ½ an inch).
- In the event that the heated water is insufficient to fill the cup up to the required height, the brewer will begin heating more water before continuing the pour. Any excess water will be cooled and returned to the reservoir for future pours. Regardless of the number of heating cycles, the machine will always aim to finish brewing when the cup is properly poured.
This is not a comprehensive list, but below is a general guideline for what will be needed:
- Single-Use Pod or Traditional Coffee Maker: This implementation could be successful using either a standard coffee filter and ground coffee or a K-Cup machine. A decision will be made based on machine availability and the feasibility of implementing our features. Ideally, we will acquire a discarded machine at a low cost.
- Microcontroller: This processor will be responsible for handling all the data that is necessary for this machine to work. It will be taking in data from the sensors and linear actuators to generate the proper commands for the coffee machine so it brews the correct amount
- Laser distance sensor (horizontal): This laser will be mounted to scan horizontally. This sensor does not require immense precision, but must be able to differentiate between the presence of a cup and empty space. A sensor with the aforementioned requirements should be affordable within the budget of this project.
- Linear actuator: This actuator will be used to control the height of the horizontal laser sensor. A method for measuring the height of this linear actuator is required to determine the approximate height of the cup.
- Laser distance sensor (vertical): This laser sensor is intended to scan downwards into the cup or tumbler. This sensor requires more precision in measuring distance. As the laser will be mounted close to the nozzle, the laser needs to distinguish between coffee in the cup and the coffee that is being dispensed. Thus, it is also important that the nozzle dispensing the coffee is also precise as to not disrupt the laser.
- LED display: As more of an aesthetic feature, this screen will display information relevant to the user. For example, using the laser measurements, the display can estimate the percentage of the cup that is full.
Demonstrated Features
- Cup height detection: The horizontally mounted laser will scan upwards until it finds the top of the cup.
- Automatic liquid pour/brewing: The device will automatically begin pouring following its detection of the cup and then finish pouring when it has detected sufficient coffee has been poured. The machine will also automatically brew coffee as needed to complete the brew.
- Interactive display: Create an interface that allows the user to dial in settings to their specific style of coffee pour while allowing the user to save certain cups. In addition, when coffee is pouring, the display will provide real-time information such as the amount of coffee poured and an estimate on how full the cup is.
- Device versatility: We want to illustrate that this device truly works with any cup you put underneath. We plan to use a variety of mugs and place some strange shaped cups underneath to show that it will be able to pour a full cup of coffee consistently.
- Automation: In the spirit of automation, we plan to automate other processes of the coffee making process, such as automatic bean grinding or automatic replacement of K-cups. Ideally, we could reuse the chassis of an old Keurig by reprogramming it. That way, we could illustrate how this technology could be retro-fitted to existing coffee machines.
- Mass Sensor: Going along with “saving” certain cups for future pours, a mass sensor underneath the cup can be used to detect the mass of the poured liquid, then convert that to the volume of poured coffee.
- Smartphone control: The user would not even need to get out of bed when making a cup of coffee with this product, as the system will allow for control from a smartphone to make a cup of coffee, while also being able to notify the user if the water is low, there are no K-Cups, or if no cup is sensed underneath the maker. A web-interface will make the process for the end user seamless.
Available Technologies
There are a number of technologies our group wishes to explore in this project.
- Lasers: In its current form, our design will utilize two different laser sensors to properly pour the right amount of coffee. Throughout the project, we will test different laser sensors for their accuracy in measuring dimensions of the cup of choice. There are many different types of laser sensors that use different methods to accurately measure distance; testing of these various devices will allow us to determine which is best. In addition, our testing may prove that lasers are indeed not the best sensor option, and that other sensors that use Lidar, ultrasonics, or photoelectrics may prove to be a better option. Cost of these sensors will also be a major factor if we aim to make our design affordable to the general public.
- LCDs/Displays: As part of our efforts to make the design more user friendly, displays will be used to show relevant information to the user. Choosing and programming this display will be time intensive. In particular, this project will test our abilities to design interesting dynamic graphics. There is also room to explore touchscreen functionality if we aim to make the displays interactive as well.
- Linear Actuators: This will be used to move one of our laser sensors up and down to detect the cup’s height. Our team is unfamiliar with these devices and will need to learn how to translate information about the actuator’s position into the cup’s height.
- Coffee Maker PCBs: It is highly likely that we will be “hacking” into the circuit board of the Keurig. This may be difficult, if not downright impossible if we face any security that the company has put in place on their boards. Nevertheless, this project will be an exploration into how the circuit board of a coffee maker works. We anticipate taking apart a Keurig and analyzing the internal circuitry that runs the machine.
Engineering Content
This project will require several different processes to render a successful and working product in the end. Similar to numerous products that provide an automated experience for the customer, this product will require significant engineering research and design upfront to provide our customer with the perfectly poured cup of coffee every time. While there are many factors to consider, below are a few key elements of the engineering process that will determine the product’s success in development.
- Tapping into current coffee-making machines: Given the nature of this being an electrical engineering project, the expertise in pouring a good-tasting cup of coffee is not something this product is looking to improve upon or perfect. We will need to do extensive research on how the process is done today or how we can tap into current technologies with our innovative product. Given current coffee making machines already have their own enclosed system, this project will require either a significant breakdown of a current coffee-maker, or the design of a brand-new coffee maker that will still make a good-tasting cup of coffee with our integrated technology but limited coffee-making expertise. At this point, it is yet to be determined whether or not we can “hack” into the Keurig’s circuit board and modify code for our use.
- Determining and Testing an Accurate Imaging System: This is the largest challenge that this project will entail, given this is the most innovative portion of our technology. While we currently intend to use laser distance sensors for our design, this choice is subject to change as to generate the highest degree of accuracy and precision in creating the perfect pour of coffee every time. This portion of the design will be quite iterative, and each iteration will require significant testing. This testing would include qualitative analysis such as the speed of the system, and the success of the pour. In addition, quantitative analysis will need to be done to see how accurate the calculations are in comparison to actual cup measurements, and whether the amount of coffee poured matches the desired volume of liquid.
- Creating an easy-to-use interface for the design: Our imaging system described above will only be effective if the user is able to see the results themselves, in addition to providing them the means of being able to control the device. Once the project progresses into the automation phase, the system will need to have an interface that allows the user to know when a K-Cup is swapped out, when a cup is or is not sensed, when the cup ounces are calculated, or when the water or K-Cup stock needs to be replaced. The innovative system is only as good as the end-user’s perception, which requires a detail-oriented design process interface.
- Fine tuning automated technologies: Integrating automation into innovative technologies always brings its fair share of hiccups, which is why many products rely on human interaction and control for smooth operation. Automating the coffee-making process will serve its own subset of challenges, as design thinking and iterative testing will be required to perfect the automated coffee-making process. The design thinking process will entail accounting for possible hiccups in the process that may occur, such as forgetting to add a cup, or there being an empty stock of K-Cups. The engineering comes in when we figure out how the system will make the user aware of these issues, in addition to not allowing the machine to cause waste or make a mess.
Conclusions
For many, getting out of bed and starting an early morning work day can be the largest challenge they face. A hot cup of coffee is a crucial part of many morning routines, providing just the right boost of energy. With the Fill ‘Er Up Coffee Maker, the simple act of leaving out a cup the night before allows one to have the perfect cup of coffee made for them without having to leave their bed. Current coffee makers only allow for a specific amount of coffee to be made, which has to be determined, or often estimated by the user given their choice of cup. Often, the sizes offered either leave coffee left to be desired, or fill mugs so high that one cannot pick them up without spilling. Our solution sets out to eliminate those issues. Fill ‘Er Up aims for the coffee-making process to be the last thing our user’s need to worry about when starting their day.
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