Objectives of LiU Formula Student 2021-2022

From an Electronics Point of View

LiU Formula Student is a student organisation at Linköping University, Sweden. Every year we design and build a formula style race car, which we race with against other universities all over Europe. We started the journey of building an electric car in 2020/21 but were not able to complete it in time for the competitions. Therefore, our main goal for 2021/22 was very straightforward – build an electric car and bring it to an international competition. From an electronics point of view this meant that a lot of new systems had to be designed, built, and tested. The original plan was to design five new PCBs, and do major redesigns of five more. However, as the project proceeded these numbers kept increasing. We wanted to use an iterative approach to the design-build-test cycle, and expected 2-4 versions of each PCB until they were running and had all their desired features. Thus, partnering with a reputable PCB manufacturer such as Eurocircuits helped immensely with the fast production of the many different low quantity orders of PCBs.

The car would feature many different circuit boards. Below follows an explanation of some of them.

Tractive System Control Unit

The Tractive System Control Unit is a logic unit which uses driver input and various sensors to put the car into suitable states (on / off / starting up / cooling down / etc.). It is fully non-programmable.

Temperature- and Current Monitoring System

The Temperature- and Current Monitoring System is part of the battery management system, which oversees the cars battery pack. As the name suggests, its job is to monitor the temperatures and currents in the battery pack, and take appropriate actions in case they get too large. The car contains 12 of these PCBs, which made it affordable to have them assembled by Eurocircuits, which saved us a lot of time.

Brake System Plausibility Device

The Brake System Plausibility Device is a safety system in the car. Its primary job is to put the car into a safe state in case excessive braking and acceleration is detected at the same time (in case something malfunctions with the electronic throttle).

Dash Shield

The car’s dashboard makes use of a screen and a microcontroller. To connect these together and to the rest of the car, a Dash Shield PCB is used.