Formula Student Racing Car

About the Team

IIT Roorkee Motorsports is a group of interdisciplinary students from IIT Roorkee. We participate in the world’s largest Inter-Collegiate Engineering competition conducted by Formula Society of Automotive Engineers (FSAE). The team was founded in 2009 and since then we have been participating across various Formula Student competitions. Currently, we are the No. 1 team in India according to Formula Student Electric Rankings.

The team consists of students of different disciplines - Mechanical Engineering, Electrical Engineering, Electronics, Industrial Engineering, and Materials Engineering. The team has different divisions such as Electrical, Mechanical, Marketing & Management and Design & Web Development which works in their respective departments.

The Car

Our latest car, the design of which has been completed, is going to be our best one yet. With this, we have decided to participate in Formula Bharat 2019 and Formula Student UK 2019. Some highlights include:

Maximum speed – 122 km/h
Overall weight (with driver) – 280 kg
Peak torque – 192 Nm
Power – 80 kW
Front and rear carbon fibre wings to increase downforce.

Our Circuit Boards

As our project is an electric vehicle, we require various custom designed circuit boards which help us manage the electrical systems and data acquisition. The boards used by us are described below.

1. Vehicle Control Unit

Vehicle Control Unit (VCU) has always been an integral part of an electric vehicle. So, we have designed our own VCU which implements most of the FSAE rules related to electric design and keeps in mind the safety and security of both the device and its user.

It contains many safety circuits like BSPD, BMS, IMD etc. together with software controls which were being operated on different signals receives from different parts of the car. We have decreased the size and volume occupied by this PCB from its previous versions and further also decreased the power requirement with the high robustness of the system. We have also increased number of external power ports and it can also handle two motor controllers simultaneously and hence can be enabled a control unit for torque vectoring mode.

Status of Project: The design as well as routing the PCB is complete. Gerber files are ready for manufacturing.

2. EV Charger

In-house charger becomes a necessary component for the formula electric cars due to unconventional voltage levels of the high voltage systems. The charger circuit will be capable to charge one module at a time at a constant current of 20 amperes.

The device includes maximum power point tracking input voltage regulation for limited power inputs such as solar panels. Other features include user-programmable absorption and equalization times, temperature-adjusted regulation voltages and external NFET isolation diodes.

Status of Project: The design for the project is complete and the PCB routing is in progress.

3. HV current and voltage sensor

We have designed our own architecture to monitor the state of charge of the battery by monitoring the instantaneous voltage and current that flows through the battery. This would help us determine the amount of energy that is being used or is remaining in the battery, thus aiding us in micro-adjusting the driving model. This is board is capable of communication protocols like SPI, UART, CAN at different logic levels like 3.3V or 5.0V; with data logging, that is done locally (on an SD card module) and is relayed to a central hub for further processing/analysis to better optimise the driving model.

Status: The design for the project is complete and the PCB routing is in progress.

4. Data Acquisition System

Almost every electrical/electronic system needs a data logging system not just for maintenance but also for fine-tuning its own variables. Our Vehicle will also use a self-designed Data Acquisition system that takes data from all other boards and some additional sensors such as speed sensor, tire temperature sensor, Inertia Management Unit (Accelerometer, Gyroscope and Magnetometer), Steering position sensor and throttle and brake encoders. Data transmission between boards will be done using CAN 2.0B interface and relevant data will be displayed to the driver on a 20x4 LCD with an 8-bit parallel interface. Besides this, all data will be stored sequentially in a microSD card through SPI interface.

Status of Project: The design for the project is complete and the PCB routing is in progress.

5. Battery Management System

A Battery Management System (BMS) is used to monitor and proactively enhance the health of the batteries. BMS monitors the SOC (state of charge) of all the cells and balances between all the batteries. A small SOC or voltage difference between the batteries can lead to large damage to batteries in the long run. BMS is mostly used during charging and it only monitors the voltage during discharging. In passive BMS, the balancing is done by discharging the overcharged cell through a power resistor. The passive BMS is not that efficient as the excess energy is wasted in the resistor but it has the advantage of being economical, less complex and small size.

Status of Project: The design as well as routing for the PCB is complete. Gerber files are ready for manufacturing.