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

BusPlan

Aashish Kapur, Connor Lake, Scott Liu

BusPlan

Featured Project

# People

Scott Liu - sliu125

Connor Lake - crlake2

Aashish Kapur - askapur2

# Problem

Buses are scheduled inefficiently. Traditionally buses are scheduled in 10-30 minute intervals with no regard the the actual load of people at any given stop at a given time. This results in some buses being packed, and others empty.

# Solution Overview

Introducing the _BusPlan_: A network of smart detectors that actively survey the amount of people waiting at a bus stop to determine the ideal amount of buses at any given time and location.

To technically achieve this, the device will use a wifi chip to listen for probe requests from nearby wifi-devices (we assume to be closely correlated with the number of people). It will use a radio chip to mesh network with other nearby devices at other bus stops. For power the device will use a solar cell and Li-Ion battery.

With the existing mesh network, we also are considering hosting wifi at each deployed location. This might include media, advertisements, localized wifi (restricted to bus stops), weather forecasts, and much more.

# Solution Components

## Wifi Chip

- esp8266 to wake periodically and listen for wifi probe requests.

## Radio chip

- NRF24L01 chip to connect to nearby devices and send/receive data.

## Microcontroller

- Microcontroller (Atmel atmega328) to control the RF chip and the wifi chip. It also manages the caching and sending of data. After further research we may not need this microcontroller. We will attempt to use just the ens86606 chip and if we cannot successfully use the SPI interface, we will use the atmega as a middleman.

## Power Subsystem

- Solar panel that will convert solar power to electrical power

- Power regulator chip in charge of taking the power from the solar panel and charging a small battery with it

- Small Li-Ion battery to act as a buffer for shady moments and rainy days

## Software and Server

- Backend api to receive and store data in mongodb or mysql database

- Data visualization frontend

- Machine learning predictions (using LSTM model)

# Criteria for Success

- Successfully collect an accurate measurement of number of people at bus stops

- Use data to determine optimized bus deployment schedules.

- Use data to provide useful visualizations.

# Ethics and Safety

It is important to take into consideration the privacy aspect of users when collecting unique device tokens. We will make sure to follow the existing ethics guidelines established by IEEE and ACM.

There are several potential issues that might arise under very specific conditions: High temperature and harsh environment factors may make the Li-Ion batteries explode. Rainy or moist environments may lead to short-circuiting of the device.

We plan to address all these issues upon our project proposal.

# Competitors

https://www.accuware.com/products/locate-wifi-devices/

Accuware currently has a device that helps locate wifi devices. However our devices will be tailored for bus stops and the data will be formatted in a the most productive ways from the perspective of bus companies.