This Fall quarter was very exciting for NUsolar. As the FSGP approaches, we are getting closer to completing Seven, our 7th generation car.
Most notably, Seven had her first day outside last November during a successful rolling chassis testing. Since then, we’ve been working hard to make sure that the mechanical and electrical hardware as well as the software of the car is test-ready before warm weather reaches Evanston. We will use this as an opportunity to review what we’ve accomplished and what is left to be done.
New Electrical Lead Akash Borde
We had a change in NUsolar’s leadership as our previous Electrical Lead Sylvia Fu moved to California for an internship at Google. We are so happy for her! In her stead, Akash Borde has taken the role as the electrical lead. Akash is pursuing a degree in Computer Engineering from the McCormick School of Engineering and he has been with the team since his sophomore year. As the Electrical Lead, Akash is in charge of the electrical team and all its projects, including setting up SC7’s battery, circuitry and solar cell array.
” I’ve always been interested in sustainability and engineering, and NUsolar is the perfect mix between the two. This quarter is very exciting because this 3 year-long project is finally reaching the finish line! Sylvia and previous leads have left a great plan in place, and our project teams are hard at work finishing the separate pieces such as our driver control board, light control board, DC/DC board, communication with the motors and data analysis. It is both exciting and challenging putting this puzzle together.”
The business team had an eventful quarter. We received many in-kind and monetray donations and grants from Northwestern and our corporate sponsors. In the fall quarter, we received the McCormick Grant, Northwestern Sustainability Fund Grant, and ran a successful Catalyzer campaign during the giving Tuesday. We also received support from Boeing and Blue Oval.
The Business Team gets the credit for attracting 4 new sponsors during the Fall quarter. Chongqing Aihua Machine & Electronic Co. Ltd became our newest platinum sponsor with a $10 000 donation. An Alumni from Google X donated 3 Tritium motor controllers to the team. Mitsubishi Materials sponsored the team with $5000 worth of drill bits and Misumi donated $1000 value of wires and connectors.
“This year I learned about how to maintain relations with sponsors, write grants and balance a complicated budget. Due to financial constraints, we had to come up with creative solutions to expensive projects. For example, we saved almost $15 000 dollars in adapting a new manufacturing process and changing the materials for our aero shell mold. One thing I am want to improve in the team is establishing a more comprehensive knowledge transfer process and how to deal with senior members graduating.”
The Goal of the battery box is to keep batteries temperatures as low as possible. We set our target to be that the batteries never exceed 45 degrees Celsius. The battery box will go in the front of SC7 and host the batteries. It has to fit in the designated area in the frame, protect the batteries from physical damage while at the same time allowing for efficient air flow. After numerous iterations, we arrive at a design that reaches a maximum temperature of 44.9 degrees Celsius and are tweaking it to see if we can reduce the temperature even further.
“Building this battery box gave me practical experiences in SolidWorks solid body modelling and flow simulations. It was hard to come up with a design that achieved the required temperatures and could be wired up. It took many iterations and discussions with both Mechanical and Electrical team members to arrive at this design”
Currently, we are in the process of manufacturing our aero shell. It is a crucial part of the project because it is the aerodynamic shell that will cover our steel frame that also houses solar cells which are an essential part of a solar car.
We are making our aeroshell from kevlar reinforced carbon fiber and we are using a foam mold for the process. The top mold has been sanded and filled; the surface area was reinforced with fiberglass, covered with resin and sanded more for a smooth finish. It was a labor intensive process that took place over the winter break. With the help from our alumni, we designed the layout of 5 layers of carbon fiber. The fiber is strong in only one direction so we had to take that into account when designing a layout. We are working on cutting the 5 layers of carbon fiber for the top shell and plan to do the layup on a two week’s time. The team has picked up the bottom shell mold from the manufacturer recently and will begin the manufacturing process after the top shell is done.
“NUsolar has given me the opportunity to gain engineering, manufacturing and leadership skills. During last quarter, I trained a team of 7 people how to manufacture carbon fiber reinforced panels and together with them we manufactured carbon fiber interior panels. Making the aeroshell is quite a bit more challenging though because of the surface size and curvature. I used our alumni and adviser network to make sure that Seven’s aeroshell is perfect.”
FEA & Structural Analysis
The Mechanical team is also currently working on the Structural Report of the car. The main purpose of the structural report is to communicate to the race directors that we have a road-safe car and to prove the competency in our engineering and manufacturing abilities. It discusses the safety features and testing performed to ensure its safety, the choice of materials and external parts.
We use FEA simulations to test each individual structural parts of the vehicle. It helps us determine if these parts can sustain required load conditions.
“Being the Mechanical Lead this year, I learned a lot not only about how to do unique projects like carbon fiber layups but also how to plan complex projects and help the team meet its milestones. I had to figure out people’s strengths and use their skills in a efficient manner, while having an overview of the team’s progress. One of the most interesting projects I am working on is the Structural Report of Seven. This is an important project because I have to review all individual parts of the car to make sure that they can sustain the required loads. “
Solar Cell Array
“I did all of the design for the solar cell array. We had size constraints due to regulation and shape constraints due to the shell. The most challenging part was figuring out how to wire the array into modules. Collaborating with D2 helped us to minimize the work required to incorporate the array to the aero shell. Like most car teams, we utilize bypass diodes to preserve the output in when a part of the array is shadowed. The previous car had bypass diodes attached manually by drilling holes in the aero shell. Seven will have laminated bypass diodes incorporated in the modules.”
Driver Control Board
The goal of this project was to modify the driver control board to accept more connectors for new sensors and temporary soldering made in race. Currently, it works together with the Arduino Duo and connects to CAN bus. The board was received and is almost done with populating. A few connectors are left to be soldered and tested.
LCD Dashboard PCB
The goal of LCD Dashboard PCB project was to create a board that can communicate to the rest of the CAN network on the car as well as signal the car’s lights. It will sit in the dashboard along with the LCD it will drive, and will connect to the CAN data about the car to provide useful information from other sensors for the driver. It will also connect with Charlie’s Light Control Board for turn and hazards. The board rev 1.0 is assembled and ready to be tested by the group programming dashboard software. Future board revisions and creation of backups remain.
“I was interested in having a place where I could actually design PCBs and electronics outside a classroom setting. The LCD Dashboard PCB is an interesting project because you have to make 4 boards be compatible and work together. “
The goal of the telemetry system is to collect, transmit, receive and analyze vehicle data from BMS, Motor Controller and Driver Controls. The current status of the project is that we can receive data off CAN. and need to confirm that we can get data off our new motor controllers and how it goes into and comes off our databases.
- Finish new CAN libraries and telemetry code
Confirm that we can receive data from our new motor controllers’
- Confirm that the data is collected correctly in the custom databases
- Receive encapsulated solar cells and mount them on the aero shell.
- Finalize populating and testing the Driver Control Board
- Perform testing of Driver Control code
- Code the inputs of LCD Dashboard Display
- Investigate the CAN features the motor controller can provide
- Manufacture top and bottom aero shells
- Mount the aero shell to the frame
- Finalize the design and build the incorporated array stand
- Finalize the design and build the battery box
- Design and build driver safety equipment
- Clean and paint the frame
- Build the adjustable pedal base, floor and seat of the car
- Install tie rod assembly and steering support
- Design the top shell latching mechanism
- Install parking brake, placing lights and ballast box
- Driver air ducts
- Finalize Structural Report
Apply for McCormick grant and Department support.
Attract new sponsors
Funding required for the car parts:
- CF panels and their water jetting
- Epoxy, Carbon Fiber, Fiber glass, Peel Ply, Breather and protective gear
- Top shell hinge, canopy hinge mount, hinge rods, hinge piston supports
- Components for driver control PCB: Current sensor, temperature sensor, driver control, steering wheel, light controls, DC/DC board
- Components for steering wheel hardware: capacitors, resistors, integrated circuits.
- Arduinos, wires and connectors, temperature sensors
Funding required for the race expenses:
- Track Fee
- Truck gas and tolls
- Van gas and tolls
How can you help?
This project would not be possible without your kind support. We greatly appreciate all the support we receive from our corporate and university sponsors and our adviser and alumni network.
You can support us with a monetary donation or by becoming a sponsor. You can learn more about it by clicking the button to the right.
We are happy to accept in-kind donations, parts and services. If you want to contribute to any of our current projects, please contact our PM.