Winter Update

Hello Everyone,

As you can see there’s lots of activity here at DFR. We’re working on the battery pack, the battery management system, the main controller for the car, the engine, and the chassis! As you saw, we were modifying the chassis up in Canada at VR3 Engineering. They worked with us to complete the job and now we have a beautiful chassis sitting in our lab!

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and here’s the old back all chopped off. Sorry DFR 2104 team members 😦

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We’ll keep this half to take suspension points off of and help place the shocks for the rear suspension. With the chassis complete we can start mounting the other components in the car!

The engine just came back from BoltonWorks in Connecticut. They did a 3D scan of the engine and created an incredibly detailed SolidWorks model from the point field they got from scanning it. This gives us an exact model to use when building the engine mounts for the car. Getting to see their facilities was a treat! Thanks guys!

On the engine testing front we’ve been in discussion about how best to test our new ECU and engine in the car. We’re discussing a test rig we can hook up to the engine while it’s in the car, more on that later after the holidays.

On the controls side we’ve managed to connect all the electrical components over CAN Bus and obtain data from them on our central controller. We’re storing this data in a SQLite database so we can access it for our control algorithms. Things are really coming along!

 

AMS: Keeping our Batteries safe

Over the past couple months, we’ve been doing research into the different options we have for the Accumulator Management System (AMS). We got into contact with Linear Technology a while back and it turned out that they’re one of Formula Hybrid’s sponsors. Luckily they were able to provide us with a demo system to evaluate their battery management solutions, sending us some boards based around their battery monitoring IC, the LTC6804-2.

We’ve been playing with the demo system over the past couple weeks, checking to see if everything seems to be working. We initially had to simulate some cells using resistors, since our cells hadn’t been delivered yet:

Simulating cells using a power supply and resistors
Simulating cells using a power supply and resistors

Luckily, our battery cells arrived right before our winter break, so we were finally able to test the demo system using the actual cells. Each board can monitor up to 12 cells, but for testing purposes we’re only using 2 cells each, check out the set-up:

IMAG1212
The whole setup: Cells connect to the boards, each board then sends voltage information to the microcontroller, and ultimately the computer

Here’s a closer look at the PCBs:

Linduino One: The Microcontroller, which acts like an Arduino Uno plus some extras
Linduino One: The Microcontroller, which acts like an Arduino Uno plus some extras
DC1942C: This is the board that takes voltage readings from the cells, it has the LTC6804 on it
DC1942C: This is the board that takes voltage readings from the cells, it has the LTC6804 on it
DC1941C, This is an isoSPI Master so that all our boards can talk to the microcontroller
DC1941C, This is an isoSPI Master so that all our boards can talk to the microcontroller

The demo system let us check if the hardware works as expected, including a GUI so that we could see everything that’s going on. It lets us see the charge in each cell, and includes options to set our Over and Under Voltage limits. It also lets us discharge cells for cell balancing purposes. Here’s a screenshot of the GUI:

LTC6804-2 GUI: You Can see it reports the cells that aren't connected as "UnderVoltage", makes sense since nothing is plugged in!
LTC6804-2 GUI: You Can see it reports the cells that aren’t connected as “UnderVoltage”, makes sense since nothing is plugged in!

Everything seems to be working on the hardware side of things, the GUI and some voltmeters helped us determine that quickly. Information is sent as expected, meaning the boards we received weren’t a dud. The next step, in the software, is proving to be pretty challenging. We have to program the boards to independently behave as we want; a lot of coding is goes into this. We’re looking at sample code from Linear Technology for some insight. More updates to come!

Mounting and Test Bench Design Coming Soon!

While we wait for our motor and motor controller components to arrive, we have been working to design component mounts, a test bench setup and testing methods that will validate our system. The component mounting plates are being created on SolidWorks and will go through force simulations to determine the force that the connections that hold the mounting plates in the chassis must be able to withstand. The mounting plates that will hold the components inside the chassis will also be used to hold the components in pace on the test bench. We are also working with the Controls System design team to determine whether dynamometer testing is the best method to validate that our motor, motor controller design, and the signals being sent to the motor controller are functional. The fabrication of the mounting plates will begin next week!

The Motor and Motor Controller Have Been Ordered!

We are pleased to announce that our motor and motor controller components have been ordered! After performing a state of the art study, and overcoming a few budget issues, we were able to acquire an Emrax 228 Mid Voltage brushless motor by Enstroj, and the Bamocard-D3 Battery Motor Controller by Unitek. The motor, motor controller and their accessories will arrive later this month. We are currently speaking with dynamometer owners to pin down a test bench site. We hope to have the motor spinning and the test bench collecting data by January.