Lab :: ECE 445 - Senior Design Laboratory

Lab

Recommended Tools
In addition to the resources that the course provides, students may find it useful to obtain the tools below: wire cutter wire stripper needle nose pliers screwdrivers hex set (ball ends) electrical tape small scissors a small file

Recommended Tools

In addition to the resources that the course provides, students may find it useful to obtain the tools below:

wire cutter
wire stripper
needle nose pliers
screwdrivers
hex set (ball ends)
electrical tape
small scissors
a small file

Lab Resources

The Senior Design Lab is located at ZJUI room D225. This lab provides you access to various equipment, some spare parts, computers, and a space to work on your senior design project. In addition, course staff will make themselves available in this lab during their office hours to provide guidance on your project throughout the semester. Your weekly meetings with your TA will also likely be at this location.

It is our intention that this laboratory space provides you and your team with all the tools you would need to develop and test your project (within reason, of course!). If there is something that you require in the lab to complete your project that does not exist in the lab, talk to your TA and we will see how we can solve your issue.

Lab Rules

There are two overarching rules of working in the Senior Design Lab (and, frankly, any shared lab). First, be safe, and second, be courteous. Lab privileges will be revoked if you fail to complete the required laboratory safety training or if you break any of the lab rules. Specific points and examples of what we expect:

Clean up after yourselves. After finishing up in the lab, all cables should be returned to the cable racks. Be sure to notify the lab staff of any broken cables. Throw out any trash that has been generated (wire clippings, scrap paper, packaging, etc). Trash and recycling bins are provided in the lab. Books and lab manuals should be put back on the shelves and kept organized.

The lab is a shared resource. Do not keep any cables from the lab with you after leaving the lab. Log out of computers after you are done (or are leaving the lab for more than 5 minutes).

Report any broken equipment immediately. If any equipment is broken, notify the lab staff and your TA immediately. if you break equipment, you must tell lab staff and your TA before the end of the day. Any attempts to conceal breakage will result in a failing grade for the course.

The lab is a food-free zone. Please do your part in helping keep the lab clean. Drinks are OK as long as they are in a spill-proof container (e.g. closed water bottle, plastic bottle).

Lab Bench Reservations

We do not expect the lab to become so crowded such that finding a lab bench to work at becomes difficult. However, in the case that this does happen (particularly in semesters with very high enrollment), we will move to a Lab Bench Reservation system. Reserving a bench guarantees that spot for you, however each team may only book one lab bench at a time, and for a maximum of 4 hours per day.

If the lab needs to move to a reservation-based system, you will be notified ahead of time.

A few ground rules:

You may use a lab bench (a) during a time for which you have it reserved or (b) any time during which it is not reserved in the system (on a first-come-first-served basis). However, if you are working at a bench that is unreserved and somebody reserves it using the online system, the group with the reservation gets the lab bench.

There is a limit on the amount of time for which you can reserve benches in ZJUI D225. The limit is currently a total of 4 hours of total bench time in the lab per group per day (e.g., 2 hours at Bench A and 2 hours at Bench B would max out your team's reservations for the day). While this may seem restrictive, keep in mind that the course serves more than 30 groups in a typical semester and the lab has only 14 benches. Also keep in mind that you can work at a bench if it is unreserved.

Some lab benches have specialized equipment at them, such as digital logic analyzers. Try to reserve the lab bench that has the equipment that you need.

Cancel reservations that you will not need as soon as possible to give other groups a chance to reserve the lab bench. You can cancel a reservation up to 1 hour before time and not have it count against your daily allotment.

Conflicts and/or reports of people not following these rules should be sent to your TA with the course faculty in copy.

Above all, be courteous. Especially near the end of the semester, the lab will be more crowded and many teams are stressed. Clean up the lab bench when you are done with it. Start and end your sessions on time. Be patient and friendly to your peers and try to resolve conflicts professionally. If we notice empty lab benches that have been reserved, we will cancel your reservations and limit your ability to reserve lab benches in the future. Similarly, do not reserve more time than you will need. If we notice that you are frequently canceling reservations, we will limit your ability to reserve lab benches in the future. Finally, do not try to exploit the system and reserve a bench for 30 minutes every hour for eight hours. We will notice this and revoke your ability to reserve a bench.

Featured Project

# Wireless Charging Table Supporting Multiple Devices with Arbitrary Placement

# Problem

While more and more device manufacturers adopt wireless charging into their smartphones and headphones, most currently available wireless charging pads only support a single device and require strict alignment between the device and the coil. Misalignment can negatively influence both user experience and charging efficiency. In certain scenarios such as cafeterias, a table that can simultaneously charge multiple devices with arbitrary placement can be useful and COOL, allowing the users to sit wherever they like and to arbitrarily place their devices.

# Solution Overview

We intend to design and manufacture a table with multiple mobile coils placed in an intermediate layer below. Driven by step motors, a tool grabber attaches the coils using electromagnets and drop them in the right place. Computer vision will be used to recognize devices (phones, AirPods, etc.) and guide the chargers to corresponding locations. Once the coil is in place, it will first communicate with the device (Qi protocol) to verify whether the device can be charged wirelessly. If yes, the charging process will start. Otherwise, the coil will be moved back to its original location. The scheduling algorithm ensures the wires get separated and neat.

# Solution Components

* Mechanical subsystem. The main moving component of the system is a large-scale X-Y moving mechanism under the table. The coils will be placed between two panels above the moving mechanism and will be caught and dropped to the right place by the moving tool head. The tool head will be developed with electromagnets or magnets with Z-axis moving capability.

![sketch](https://courses.grainger.illinois.edu/ece445zjui/pace/getfile/18618)

* Vision detection subsystem. This includes a camera and a processing unit. It detects the locations of phones and other chargeable devices and send their positions to the control unit. In real-world settings, pre-installed surveillance cameras may be used as the video source so that no additional camera is required. Embedded GPU (NVIDIA Jetson Nano as a candidate) or cloud service can be used for image processing.

* Power supply control. It is used to control wireless chargers and supply power to devices if and only if the handshake between charger and device is successful. Status will be reported to the central control unit.

* Central control unit and embedded software. According to the output given by the vision detection system or the feedback from the power supply system, the central control unit should move the chargers with proper scheduling algorithm to pair chargers with devices and keep wires of coil separated and neat.

# Criterion for Success

* The vision detection system can localize chargeable device at an accuracy of over 80% and response within 2s.

* The power system can supply powers when a chargeable device is present, and not supply power when the misdetection happens. Correct feedback can be sent to the central control system.

* The mechanical system moves correctly according to the commands given by the central control system.

* The central control system can send correct commands to the mechanical system given the position information from the vision system and the feedback from the power supply system. It should be able to keep wires of charging coil separated.

# Evaluations on Alternative Solutions

The technology of wireless charging emerged some time ago, but its inclusion in commercial devices doesn’t take off until recent years. Intuitively, wireless charging doesn’t bring much additional convenience compared to the wired charging, but its adoption by major manufacturers has proven its value. Similarly, in certain settings such as the cafeteria, charging without alignment may significantly increase user experience, comparing to having only a few fixed charging locations.

An alternative solution to enable table-scale wireless charging is to deploy multiple coils covering the whole table. But it doesn’t solve the alignment problem unless the coils are heavily overlapped, which has been proven to be difficult by already canceled Apple AirPower.