Whirlpool Dispenser Cup

Transcription

1 Whirlpool Dispenser Cup Michigan State University Senior Design ECE 480, Team 8 Spring 2015 Project Sponsor Whirlpool Project Facilitator Dean Aslam Team Members Daniel Sun Gao Xin HongYi Shen Connor Grossman Daniel Gomez

2 Table of Contents 1. Executive Summary 1. Background 2. Design Approach 2. Technical Summary 1. Customer Requirements 2. Microcontrollers 3. Power Supply 4. Sensors 3. Design Stages 1. 3D Model of the Dispenser Cup 2. Active Bandpass Filters 4. Fast Diagram 5. Project Management 1. Technical Responsibilities 2. Non Technical Responsibilities 3. Gantt Chart 6. Budget 7. Conclusion/Recommendation 8. References 9. Appendix

3 1. Executive Summary 1. 1 Background Whirlpool Corporation is one of the largest washing machine manufacturers. It s headquartered in Benton Charter which is a township in Michigan. The Company was founded on November 11,1911. At the very beginning, it was a small company that produced electric, motor driven, wringer washers. With the science and technology developing rapidly, most families choose to use a washing machine at home instead of doing laundry outside washing by hand or driving to the laundromat. So the rigid demand of having a household washing machine increased rapidly. Whirlpool growing fast and becoming one of Fortune 500 company,having an annual revenue of about 19 billion dollars. They have more than 70 manufacturing and technology research centers in the world. However a the new problem also came up, which is how to use the least energy to wash the cloth clean. Being energy efficient and to be environmentally friendly are two big problems for the manufacturer. In addition, with the fossil energy being scarce, the government and many environmental protection organizations are pressing this issue. Energy Star is an international standard for energy efficient consumer, it was created in 1992 by the Environmental Protection Agency and the Department of Energy. It aims to encourage the manufacturer to design the most energy efficient product. We can see the Energy Star label on most of whirlpool products on the market.the label shows how much energy and money it can save a customer every year. For the customer, they take this into their consideration

4 when they choose the product.. Now, many companies like whirlpool are willing to fund the research to find a more economically feasible way to reduce energy cost. 1.2 Design Approach The aim of this project is to prototype a completely functional, yet independant, dispenser cup. The independence of this system means that no contact pads or harnesses can be used in between the appliance and the dispenser cup. Our design will not be streamlined into the market, but rather, it s a proof of concept that the requirements set by Whirlpool are feasible and can be used in future works relating to our project. By combining an LED and a photoresistor sensor we can detect when a liquid is placed in one of the cups on the dispenser. Along with the sensors, there will be a bandpass filter that is different for each cup sensor for increased accuracy and more reliability. It is left up to the user to pour the correct contents into the specified cup or the system will not work. In addition to the sensor, the system must provide its own power since it must be independant from the appliance. A solar cell on the outside face of the dispenser will always be exposed to the environment and convert light in the surrounding area into energy used to charge a battery, which in turn, powers the system. Another feature is to make the system independant. This can be done by implementing wireless communication between the

5 appliance and the dispenser cup. Using a wireless transceiver, the appliance and dispenser cup can communicate with each other without the use of contacts pads or harnesses. The last feature of the system, is user friendly LEDs to indicate which cups need to be filled depending on what cycle the user selects. This ties into the concept of wireless communication. The user will select a cycle the appliance will then wirelessly communicate that cycle to the dispenser cup and from there the LEDs light up the appropriate cups. 2. Technical Summary 2.1 Customer Requirements The customer has a functional dispenser cup with content detection that uses LEDs and sensors to detect which dispenser cup has a liquid or powder in it. From there they wish to determine the actual substance based on which cup was filled. To make the appliance lower cost and more efficient, the customer has asked us to implement wireless communications between the appliance control unit and the dispenser. The dispensers are mostly used in washing machine appliances which tend to vibrate a lot, making wireless communication a key factor for the dispenser and appliance. Another task is to implement LED s to light up with certain cycles of the washing machine are selected so the user knows which cup needs to be filled in order to perform that cycle. Wireless power is another feature that must be implemented in the dispenser. All of this

6 is to make the dispenser physically independent from the appliance control unit so that the dispenser can be removed and cleaned if needed. Overall there are three task we need to accomplish: 1. To have the appliance control unit tell the dispenser which cups need to be filled and have it tell the user via LEDs 2. To power the dispenser independently 3. Wireless communication between the appliance control unit and the dispenser for future features of the system 2.2 Microcontrollers The microcontroller that will be used for the initial and testing stage is the EZ430 RF2500. This microcontroller consists of two separable boards that connect together when they are being programmed. Both boards are identical and can perform the same task, so each board can act as a transceiver to send information between each other. This microcontroller was selected for the testing phase because of its ease of use and its wireless capabilities. One of the boards would be placed in the main system while the other is placed in the dispenser cup, allowing for easy and reliable communication between the two. However, one of the design goals is to keep costs to a minimum, to reduce costs it would be necessary to change microcontrollers as the EZ430 RF2500 proves to be very expensive. One way to reduce the cost is by using a cheaper microcontroller. A microcontroller that meets this criteria is the MSP430 G2553. The only problem with this microcontroller is

7 that it does not have the wireless transceiver to communicate with the main system. Therefore the team has implemented a new transceiver, CC2500. This will implement the wireless communication part of the system. The team will have to code the wireless communication of the devices which is one of the disadvantages when compared to the EZ430 RF Power Supply One of the main customer requirements is for the dispenser cup to be self powered. As previously mentioned there must be no contact pads or cables between the main system and the dispenser cup. One of the first solutions the team came up with was to flow current through a coil in the main system, then this coil would propagate an electromagnetic field than would be received by a coil placed in the dispenser cup this would induced voltage onto the second coil and would wirelessly power up the dispenser cup system without the need of contact pads or cables. However, the more voltage that was needed in the second coil then the bigger the coils would have to be. This proved to be as challenge, as the proposed circuitry needs a decent amount of voltage and current. Another disadvantage is the distance that the voltage can be transferred is really minimal, which may or may not be an issue in our design. Instead of this idea, the team opted for a different method. The next method will accomplished the task by using a solar cell, this solar cell would not be the main supply or the system. It would be used to charge a battery that would act as the voltage supplier for the rest of the circuit. Then the main voltage in the supply would be stepped down to get the voltages that are necessary in the circuits

8 shown on (figure 2 3 1), these are the 3.3V to power the microcontroller and the voltage divider and 5V to power the LED used in the sensor and 9V for the bank of LEDs that would let the user know what cups to fill. Figure Sensors The overall goal of our sensor system is to detect the contents that are placed inside the cups. We plan on using a photoresistor and an LED to accomplish this. On one side of the cup there will be an area for the LED to shine and the other side will have an area for the photoresistor to be exposed to the light of the LED. Once the photoresistor is exposed to the light the resistance changes. In darkness, the resistance is really high and vice versa when exposed to bright light. With contents in the cup we can measure the voltage across the resistor (figure 2 4 1) at that time, then use a microcontroller to detect this voltage and tell the dispenser cup that there are contents in it. This value will be different depending on the material thats is the cup.

9 Figure Design Stages 3.1 3D Model of the Dispenser Cup The Dispenser cup has three layers with different functions, when assembled together it creates the dispenser cup. The dispenser cup contains three cups for detergent, bleach and softener. Also, there will be three LEDs besides each cup in the first layer. In order to decrease the waste of detergent/bleach/softener, a unflat cup bottom has been designed as the second layer. The bottom layer is to store the microcontroller, battery and other circuits. There is also a common path for detergent/bleach/softener to go through to the washer.

10 Figure First Layer

11 Figure Second Layer Top Figure Second Layer Bottom

12 Figure Bottom Layer Top Figure Bottom Layer Back

13 Figure Assembled Dispenser Cup Top Figure Assembled Dispenser Cup Right

14 3.2 Active Bandpass Filter An active bandpass filter is to be implemented with the sensors. The sensors in our dispenser cup are used to detect when contents are pour into the cups. Are sensors will be sensitive to light due to the photoresistor in the sensor design. This means that ambient light from the environment around the dispenser cup will continuously be affect the value of the photoresistors. To solve this problem we are going to integrate three different bandpass filters (figure 3 2 1), one for each cup. This should make our sensors less sensitive to ambient and overall make them more reliable. The reason we need three different bandpass filter is due to the fact the each liquid (detergent, bleach and fabric softener) will refract the light of the bright red led differently, which yield a different wavelength/frequency for each liquid. After calculating how each liquid changes the light we can start designing the filters. All a bandpass filter is a high pass filter and a low pass filter in series. You first design the high pass filter to take care of the low end of your frequency range. After choosing a low end frequency (f1) and a value of C1 use equations 3 2 1, & to solve for all other unknown values. R 1 = 1/( 2 * π * C 1 * f1) Eq R 2 = 1/(2 2 * π * C 1 * f1) Eq C 1 = C2 Eq The next step is to design the low pass filter by picking the high end of the frequency range (f2), pick C1, and use equations & C 2 = C 1 * 2 Eq R 1 = R 2 = 1/(2 2 * π * C 1 * f2) Eq

15 Finally, the last thing to do is to figure out Cout but that is easily solved by taking a value thats times larger than C1. Figure 3 2 1

16 4. Fast Diagram The following function analysis system technique (FAST) shows the relationships between selecting a washing cycle to actually starting the cycle. Each box represent an action that should have happened and each box before and after it are the actions before and after.

17 5. Project Management 5.1 Technical Responsibilities Name Responsibility 1 Responsibility 2 Responsibility 3 Selection of Parts and Ordering Research Prototyping & Refinement Daniel Sun Photoresistors Design Approaches Building/Testing Prototype Connor Grossman RGB LEDS Active Bandpass Filter Daniel Gomez Microcontroller Power Supply/ Voltage Divider Building/Testing Prototype Programming Microcontroller Hong Yi Shen Rechargeable Battery Background Material Programming Microcontroller Gao Xin Solar Cell Detergent/Softner/ Bleach Building/Testing Prototype 5.2 Non Technical Responsibilities Name Daniel Sun Connor Grossman Daniel Gomez Hong Yi Shen Gao Xin Responsibility Project Manager Documentation Preparation Lab Coordinator Presentation Manager Project Webmaster

18 5.3 Gantt Chart 6. Budget Parts Cost 20 piece of k ohm photoresistors $4.22 9V Battery $9.65 Solar Cell $6.95 RGB LEDS $9.95 Microcontroller Varies Detergent/Bleach/Softener $40~

19 3D Model printing Total Varies Varies 7. Conclusion/Recommendation The recommendation that has been provided is to use the EZ430 RF2500 microcontroller through the testing stages along with our design. If cost need to be further reduced, Whirlpool will need to consider using the MSP430G2553 along with the CC2500 Transceivers. 8. References 9. Appendix