Project

# Title Team Members TA Documents Sponsor
26 Network Power For Automobile
 Akash Chandra
Constantin Legras
Dhruv Kulgod
 Matthew Qi design_document1.pdf
final_paper1.pdf
photo1.png
photo2.png
presentation1.pdf
proposal1.pdf
# Network Power For Automobile

Team Members:
- Akash Chandra (akashc3)
- Constantin Legras (clegras2)
- Dhruv Kulgod (dkulgod2)

# Problem

We were inspired by number 28 from the ECE power project ideas page and the work on UIUC’s electric Formula SAE team, IEM.
Automobiles contain complicated wire harnesses. In place of this complexity, manufacturers are trying to move to a “one power one communication” arrangement in which all control and conversion is local.

However, all components on a car cannot run on the same voltage. For example, the IEM car contains components running at 3.3V, 5V, 12V, and 24V! While some of these voltage conversions are handled on PCBs themselves, there are still many different voltages that have to be run through the wire harness. This need is due to the various devices (notably sensors, actuators, cooling/heating devices) that are present on cars. Trends towards increased safety and self driving in the automotive industry mean that the number of such devices will only increase in the coming years.

# Solution

This project involves the design of a multiple-output power supply that can handle an input range of about +11V to +15V, thereby serving a range of vehicular platforms running at various LV voltages. Our project will support four simultaneous power rails. Each rail can be configured to one of the following output levels: 3.3V, 5V, 12V and 24V. This creates a single versatile product that can be modified for the specific needs of each use case.

There will be an external backplane that houses an MCU, and a power PCB that will house the power electronics. The backplane will contain the power input, power output, and the CAN connection to the rest of the car.

There will be two variants of the power PCB: one serving the 3.3 - 5V range and another serving the 12 - 24V range. Each power PCB will contain the power electronics to buck or boost the voltage, talk to the MCU over a digital protocol, and share voltage and current usage to the MCU. The power PCBs will slot into the backplane. This will allow users to run multiple outputs simultaneously without worrying about heat generation affecting the other units. This design also allows us to quickly replace dead units without needing to redo the entire project. The two variants will have similar design, differing only in ICs and inductances.

## Backplane

We will use an MCU on this PCB to control the whole project. We will use a CAN transceiver to talk to the rest of the car. There will also be programmable termination for the CAN bus.

Relays on the outputs will ensure the output voltage is not prematurely connected to the load and the unit can be disconnected from loads in an event of a short.

To step down the voltage for the MCU, we will use LDOs to generate 5V and 3.3V rails for the ICs on the backplane. There will also be a voltage reference to provide the STM with accurate analog reference to measure the thermistors on the power PCBs. There will be a low pass filter with op amps on the back plane to help remove any switching noise from the measurement.

There will be a digital isolator to allow the MCU to communicate with digital IO for a digital enable signal or an alarm signal output.

### Backplane Solution Components

Parts used:
1. TCAN1044AEVDRQ1 - CAN transceiver
2. 744235900 - CAN Choke
3. TVS Diodes (CAN) - DIODE-SOT23_PESD1CAN
4. CPC1017N - Solid state relay used for programmable termination
5. ISO6721-Q1 - Digital Isolator
6. STM32F4 - MCU
7. J1031C5VDC.15S - Relay
8. REF20-Q1 - Voltage reference for the STMs ADCs used for the power PCB thermistors
9. BCS-110-F-D-TE - Card connector
10. LM2902LVQDRQ1 - Op Amp
11. 3413.0328.22 - SMD input fuse, 10A
12. SPX1117M3-L-3-3/TR - 3.3V LDO
13. SPX1117M3-L-5-0/TR - 5V LDO
14. MPSS-08-16-L-12.00-SR - Backplane to car connector

## Power PCB

This will house the DC-DC controller, switches, and the voltage and current sensing chips needed to buck or boost the voltage to the level commanded from the microcontroller.

There will be a thermistor on the PCB to allow for temperature monitoring on the power PCBs for safety and protection.

### Power PCB Solution Components

1. LT8253 - Buck-Boost controller IC
2. INA780B - Current shunt & Voltage sensing
3. INFINEON IPZ40N04S5L-4R8 - Switches
4. COILCRAFT XAL8080-682ME - Main inductor
5. NCU15XH103F6SRC - Thermistor
6. TSW-110-08-F-D-RA - Edge connector

# Criteria For Success

1. Supply 3.3V, 5V, 12V and 24V rails at 2A per rail for 1 hour with no chip above 100 C
2. Have a voltage ripple of only 5% on the power rails under a 1A load
3. Have a current ripple of 5% under a 1A load
4. MCU sends power usage data over CAN
5. Use CAN to change the voltage level of the power modules

Electronic Replacement for COVID-19 Building Monitors @ UIUC

Patrick McBrayer, Zewen Rao, Yijie Zhang

Featured Project

Team Members: Patrick McBrayer, Yijie Zhang, Zewen Rao

Problem Statement:

Students who volunteer to monitor buildings at UIUC are at increased risk of contracting COVID-19 itself, and passing it on to others before they are aware of the infection. Due to this, I propose a project that would create a technological solution to this issue using physical 2-factor authentication through the “airlock” style doorways we have at ECEB and across campus.

Solution Overview:

As we do not have access to the backend of the Safer Illinois application, or the ability to use campus buildings as a workspace for our project, we will be designing a proof of concept 2FA system for UIUC building access. Our solution would be composed of two main subsystems, one that allows initial entry into the “airlock” portion of the building using a scannable QR code, and the other that detects the number of people that entered the space, to determine whether or not the user will be granted access to the interior of the building.

Solution Components:

Subsystem #1: Initial Detection of Building Access

- QR/barcode scanner capable of reading the code presented by the user, that tells the system whether that person has been granted or denied building access. (An example of this type of sensor: (https://www.amazon.com/Barcode-Reading-Scanner-Electronic-Connector/dp/B082B8SVB2/ref=sr_1_11?dchild=1&keywords=gm65+scanner&qid=1595651995&sr=8-11)

- QR code generator using C++/Python to support the QR code scanner.

- Microcontroller to receive the information from the QR code reader and decode the information, then decide whether to unlock the door, or keep it shut. (The microcontroller would also need an internal timer, as we plan on encoding a lifespan into the QR code, therefore making them unusable after 4 days).

- LED Light to indicate to the user whether or not access was granted.

- Electronic locking mechanism to open both sets of doors.

Subsystem #2: Airlock Authentication of a Single User

- 2 aligned sensors ( one tx and other is rx) on the bottom of the door that counts the number of people crossing a certain line. (possibly considering two sets of these, so the person could not jump over, or move under the sensors. Most likely having the second set around the middle of the door frame.

- Microcontroller to decode the information provided by the door sensors, and then determine the number of people who have entered the space. Based on this information we can either grant or deny access to the interior building.

- LED Light to indicate to the user if they have been granted access.

- Possibly a speaker at this stage as well, to tell the user the reason they have not been granted access, and letting them know the

incident has been reported if they attempted to let someone into the building.

Criterion of Success:

- Our system generates valid QR codes that can be read by our scanner, and the data encoded such as lifespan of the code and building access is transmitted to the microcontroller.

- Our 2FA detection of multiple entries into the space works across a wide range of users. This includes users bound to wheelchairs, and a wide range of heights and body sizes.