Newsletter design phase 2017 by Chalmers Formula Student

CFS18 NEWSLETTER

Chalmers Formula Student

Design Phase 2018

DESIGN PHASE December 2017

Chalmers Formula Student

End of Design The team was formed by the end of September and then it all started. Team building events such as Sauna and dinners were held in order for the new team to get to know the members that will work hard together for the next nine months. As the pre-study phase begun, the team started to make research about solutions and possible obstacles to come for the new car. With help from alumni and partners, the team created a concept for the CFS18 car while moving into the next phase; the design phase. While designing the car, a mid-design presentation was held to present what the team had done so far. As the snow and the cold came to Gothenburg the car started to take form. A couple of events such as Stora Leverantörsdagen, Rädda Ägget and eCar Expo took place and CFS18 was there. By using simulations and 3D-modelling the CFS18 car was one just in time for the design phase to end.

“By working as a team CFS18 will, with unified channels, data driven decisions and learning in focus, build a 2WD electric race car. The car shall run at 16th of May 2018, have a minimum of 14 consecutive days of competition preparations and weigh less than 190 kg. As a result, CFS18 shall finish Top 8 in all events and Top 5 overall at FSG 2018 and compete in another competition

Team goal

and

Every year CFS sets a goal to aim for during the year. It makes the team work hard together to be able to achieve the goal. This year CFS18 will aim for a 2 wheel drive car and to be one of the top teams in competitions. Each subgroup also have a subgroup goal that describes more in detail how they will contribute to the overall team goal.

results. Doing this CFS18 aim to

place

with

comparable

increase the team’s visibility and build a wider platform for future teams.” Team Goal CFS18

The timeline of CFS18 CFS18

MID-DESIGN PRESENTATION Chalmers Formula Student

December 2017

The Frame subgroup at the Mid Design Presentation held on the 22nd of November 2017.

Mid-Design Presentation CFS18 presented their design concepts on the 22nd of November to alumni and partners at the Mid-Design Presentation. Each subgroup talked about what they have achieved and what they are working on. The Final Design presentation will be in the beginning of February 2018, where the team will present the final design of the car. The team was able to share the design considerations and solutions with firm motivations and give a complete picture to the audience by joining all the dots. The presentation was followed by fika and discussions. As always, the presentation proved to be a good way to put the whole teamâ&#x20AC;&#x2122;s status on the table and also provided an opportunity to get feedback from alumni and partners. The Mid-Design Presentation also gave an opportunity for our partners to interact with the future engineers of CFS18.

Design Lockdown The last part of the design phase is the design lockdown which takes place the 16th of December 2017. The final design of the CFS18 car should then be complete and ready to manufacture in the beginning of 2018. To design a whole car within two months is a hard task, but working as a team CFS18 will make that happen.

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Stora Leverantörsdagen Annual Suppliers Forum is a fair where suppliers and carmakers in the automotive

industry

gathers

for

exhibitions and seminars. This was

held at Lindholmen Science Park in Gothenburg in September and CFS18 got the chance to be there with the CFS17 car and talk to old and new partners. During the day there were many

seminars

from

different

CFS ALUMNI Name: Arez Moheeden Study: B.Sc. Mechanical Engineering M.Sc. Applied Mechanics Which year were you in CSF and what was your subgroup/responsibility? “I participated in CFS for 2.5 years. My journey started with being trainee during competition season 2014/2015. This was the first year, when CFS built an electric car. The competition year after, 2015/2016, I was project engineer. Initially, during pre-study and design phase, I was a part of the

companies. They talked about the

Aerodynamics group. I was also handling most of the sponsorships and

events during this year in suppliers

partner contacts simultaneously. As soon as the design phase ramped

and the automotive industry compared

down, I became a larger part of the Communications group. My time with

to privious year.

CFS came to an end when I started my master's thesis 2017, but before this I was one of the mini-managers for the 2016/2017 team.”

New for this year is that the CFS17 car will be remade into a autonomous car by students from Chalmers. Both CFS and CFSD (Chalmers Formula Student Driverless) were at the fair with the CFS17 car.

What is your current job? “Consultant at ESSIQ. My current task is at CEVT, as design engineer and component responsible.”

How did CFS help you with your job/searching for a job? “I came in touch with ESSIQ when I was looking for new sponsors and established a great relationship with the company. When I started my master's thesis at Volvo, ESSIQ asked me to become student ambassador. As soon as I completed my thesis, I decided to stay at ESSIQ as consultant.”

Do you have any advice for the new team? “I believe that it is crucial to respect the team goal. It should be the only guidance to how every team member contributes and works during this year. Also, don't forget to arrange non-CFS related activities to maintain positive team spirit. CFS18 at the Stora Leverantörsdagen 19th of September 2017

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CFS ALUMNI

eCar Expo This fair took place at Eriksbergshallen in Gothenburg in the beginning of

Name: Lars Wallin

November. The event lasted for three

Study: B.Sc. Mechanical Engineering

days with only electric and hybrid cars.

M.Sc. Automotive Engineering Congratulations on the first place of WTCC! How does it feel and what is your next step after this? “Thank you so much! It feels great to have reached the goal and so awarding after all the hard work that everyone has put in to become world champions. Now we are enjoying the victory and wrapping up the WTCC project.”

Which year were you in CFS and what was your subgroup/

responsibility? “I started as a trainee in 2012 and become a project engineer in 2013. I

CFS18 got a really good spot next to our friends, KTH Formula Student, which is a formula student team from Stockholm. Together both teams talked to the visitors about the project and the big competitions to come. During the three days at the fair CFS gained contacts, interviews from the local radio station and the camera team of the fair. CFS also got the opportunity to talk to the companies that stood at the fair. They helped us with some input

was part of powertrain subgroup and was responsible for cooling,

and their knowledge was of great value

lubrication and fuel system on CFS13. After new year I took on the role

to us to be able to continue develop one

as chief mechanic. When we were finished with CFS13 I was not tired of

of the world’s best Formula Student

Formula Student so I stayed as a manager for CFS14 powertrain and

cars. Before the fair, eCar Expo made a

chassis subgroup.”

post about the two Formula Student teams on their webpage, it can be read

What is your current job?

in this link (in Swedish).

“I am an engine engineer at Cyan Racing. Back at base in Gothenburg I design the engines and the components around them. On track I work with calibration and service to make sure that engine is performing at the maximum all the time.”

How did cfs help you with your job/searching for a job? “Formula Student is well known by the automotive industry and they know that the student that have taken part in the project is well prepared for the work in the industry. I felt that it gave me a big advantage when was searching for job, especially since I wanted to work in motorsport.”

CFS18 with alumni at the eCar Expo on the 10-12th of November 2017.

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Meet the Team! Chalmers Formula Student 2018 is a diverse group of 35 students who are from six nationalities and study nine different master programs. The diversity of the team is very beneficial, it provides plenty of approaches and perspectives to the problem solving during the project. It is also fun to get to know members from different part of the world and discover the culture clashes. Chalmers Formula Student is divided into seven different subgroups where every subgroup has their own area of responsibility and assignments. The subgroups has between two to seven members and even though the team is divided into groups it is important to collaborate between them. The team goal, which can be seen on the second page, is what every group are working towards and together the team will aim to achieve it. On the following pages the different subgroups and their responsible areas are introduced.

CFS18 at the Mid Design Presentation held on the 22nd of November 2017.

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9 Masters Programs M.Sc. Automotive Engineering M.Sc. Applied Mechanics M.Sc. Materials Engineering M.Sc. Production Engineering M.Sc. Systems, Control and Mechatronics M.Sc. Product Development M.Sc. Electric Power Engineering M.Sc. Embedded Electronic System Design M.Sc. Communication Engineering

Communications Communications is a rather unique subgroup since it is the only subgroup that neither designs nor manufactures the car. Instead Communications is responsible for the different static events at the competitions and the overall communication. So far in the project the major tasks for the Communications has been to organize both the internal and external communication. Internal communication contains of, among other things, to work with the newly developed software Yolean (a digital post-it planning tool) and leading the team meetings. The external communication has been working with the new design of our webpage, maintaining and finding valuable partners, getting started with our social media and going to three fairs. When the project now is changing from the design phase to the manufacturing phase Communications is also responsible for the coordination of our three manufacturing subgroups; metals, plastics (carbon fibre) and electronics. Since we are producing around 95% of the car ourselves it is important that the communication and coordination within the team is working. Also during the manufacturing phase Communication will develop the Business Plan Presentation and coordinate the Cost and Manufacturing Event, which are two out of three static events in the competition.

Josefine Johansson

Anna Palmqvist

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

B.Sc. Mechanical Engineering M.Sc. Production Engineering

• • •

Partner Relations Social Media Business Plan Presentation

Internal Communication Manufacturing Coordinator Cost and Manufacturing Event

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Aerodynamics During the design phase the aerodynamic subgroup has investigated a number of new concepts. Much work has been put into improving the undertray of the car. The concept of a diffuser was investigated. However this did not prove effective combined with the rest of the aeropackage. Furthermore, the subgroup has choosen to go for a floor with integrated channels acting as diffuser instead of side wings. A lot of effort has also been put into the front wing. For this year the decision was made to use an additional flap for the inner part of the wing. This means that the outer part of the wing will consist of two flaps and the inner part of three flaps. In addition investigations have also been made regarding the front wing mounting. This year the team will use aluminium brackets mounted to the front of the monocouque, resulting in less disruption of the airflow. For the rear wing it is currently under investigating however a gain in downforce can be achieved by cambering the main segment, meaning altering the curvature of the wing profile.

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Erik Josefsson

Filip Ljungström

B.Sc. Engineering Physics M.Sc.. Applied Mechanics

B.Sc. Mechanical Engineering M.Sc.. Applied Mechanics

• •

Cooling simulations Side structure

Structural analysis Front wing

Johan Idoffsson

Johan Larsson

B.Sc. Mechanical Engineering M.Sc. Applied Mechanics

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

• •

CAD Rear wing

CAD Under body

Chassis The aim of the Chassis subgroup is to provide a stable platform for other subgroups and the drivers to perform at their best. Using data driven decisions we will deliver a safe, manufacturable and accessible sub 32 kg carbon fibre monocoque. As we are coming closer to design lockdown, the CAD models of the chassis components are all locked in design and are now being optimized for ideal ergonomics and performance. Design always goes hand in hand with analysis and in our case we use FEA methods and the software ANSYS to examine the load conditions, bending and torsional stiffness of the monocoque. This helps in deciding the layup needed in different sections of the monocoque. With this data, we have started making test panels to verify structural equivalency. We have also conducted several iterations in a wooden ergonomics mock-up to optimise the driveability of the vehicle. It keeps in mind the 98th Percentile male driver and 5th Percentile female. The driver’s cockpit is designed based on this mockup, including steering wheel position, firewall, harness, pedal box travel and roll hoops. We are also planning to 3D print harness brackets in steel.

Aron Steinn Guðmundsson

Bharat Mehta

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

B.Sc. Mechanical Engineering M.Sc. Materials Engineering

• •

Impact attenuator Pedal box

Ergonomics Firewall

Anthony Jayanath Vivek

Markus Yechouh

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

B.Sc. Mechanical Engineering M.Sc. Applied Mechanics

• • •

• •

CAD Inserts Packaging

FEM layup Monocoque layup

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Suspension and Unsprung Mass For the Suspension and Unsprung Mass subgroup the design phase of the project has been focused around refining the suspension kinematics from last year. In addition to small changes in camber, caster, kingpin and other suspension parameters. One of the main changes is to reduce the difference in roll center height on the front and rear axle. With this adjustment, we hope to achieve a better response of the car during corner entry compared to last year. The linkages and the actuation system have been designed around the new hardpoints using CAD. This year Suspension and Unsprung Mass have also decided to redesign the carbon fiber rims to be a bit wider, with the goal to increase the grip performance of the tires. The rim stiffness of last year’s design has been validated through testing. The results have been used to compare the real stiffness of the rim with the simulated stiffness.

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Sumukh Kumble

Dipesh Rohan

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

B.Sc. Mechanical Engineering M.Sc. Applied Mechanics

• • •

•

Hubs Uprights Brake system

Rims

Xunbo Yang

Abhishek Shetty

Jakob Laurell

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

B.Sc. Mechanical Engineering M.Sc. Production Engineering

B.Sc. Engineering Physics M.Sc Systems, Control and Mechatronics

•

• •

Kinematics

Linkages Actuations

Vehicle dynamics Torque vectoring

Mechanical Powertrain As members of the Mechanical Powertrain subgroup, we are focussed on providing a reliable powertrain system for the CFS18 car in conjunction with other subgroups. We are working on the mechanical parts of the electric motors, the gearboxes and driveshafts, storage and protection for batteries and electronics and the cooling system. Our main aim is to optimize and design better performing and lighter subsystems than CFS17 but keeping the same design principle as a continuous improvement process. To do this we first collected the CFS17 data and alumni feedback and assessed various possibilities of improvement. We have developed a solution to remove the sun gear from the motorshaft without damaging both due to the press fit. We have started doing tests on aramid fiber composite, which will replace aluminium for the accumulator storage, and save 2 kg. Three different encoder housings are being designed to accommodate three different encoders to help test them during bench testing later. New fans for radiators were selected to save weight of 640 grams compared to CFS17. Packaging of all the components inside the monocoque is done carefully in CAD, with regular clash checks as the constraints are high.

Emil Borglund Asper

Shreyas Ramesh

B.Sc. Mechanical Engineering M.Sc. Materials Engineering

B.Sc. Mechanical Engineering M.Sc. Automitive Engineering

• •

Battery Box P.E. Box

Motors Gear Box

Akshay Dalia

Vineet Tayur Nagendra

B.Sc. Mechanical Engineering M.Sc. Automotive Engineering

• • •

Radiators Fans P.E. Cooling

Cooling Jacket Battery Box Relay Box Cooling CFS18

Electrical Powertrain The aim of the Electrical Powertrain subgroup is to provide a reliable and efficient two-wheel drive electric drivetrain. The group started off with analysing the solutions of previous years and other Formula Student teams and benchmarking it. Benchmarking led to development of functional and solution model and a summary of probable improvements, the team started the design phase of the project. The design phase started with virtual development of circuits in simulation softwares and also space claiming through CAD. The simulation of improved Pre-charge, Accumulator Isolation Relay sensing, Accumulator Indictor Light and High Voltage sensing circuits were done on MATLAB. A detailed electrical and thermal analysis was carried out on all the circuits to determine the parameters. Similar analysis was carried out to determine the rating of HV wiring, encoder and protection system. With the finalization of circuit components, the team is in the process of developing PCB to test the working of circuits in real time. Along with ordering of Battery cells and motors the team is preparing a detailed plan for manufacturing phase.

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Baradwaj Raghuraman

Biju Jude

B.Sc. Electrical Engineering M.Sc. Electric Power Engineering

•

Inverters

Relay Box

Yeongju Jin

Shayan Halder

Henrik Norbäck

B.Sc. Electrical Engineering M.Sc. Electric Power Engineering

•

PCB Design

Motors

Accumulator

Low Voltage The sensors have been decided. It will be around 220 sensors, with the main part of the sensors being inside the battery for the BMS. A big discussion has been whether to use tire temperature sensors or not during testing with a temporary testing rig. Since these sensors are expensive and hard to mount this decision has been moved to the manufacturing phase, when a decision can be made if there is time to implement it or not. All analog RC-filters for the sensors have been designed. Currently working on the filter for the current sensor, which is slightly more complicated than a RC-filter since it contains a differential amplifier to be able to compare the output with a set threshold. Currently working on the design of the BMS. This year it will be a carrier board solution where all the connections between the BMS slave boards and the battery cells will be through a PCB containing the temperature sensors and fuses which will be directly mounted on the cell stack. This will ease the problems if a BMS slave board will break since it is only to disconnect it without soldering and then plug in a new one.

Martin Johnsson B.Sc. Computer Science M.Sc. Systems, Control and Mechatronics Engineering

•

Software

Mikael Pähn B.Sc. Computer Science M.Sc. Electric Power Engineering

• •

Sensors TSAL

Xin Chen

Richard Burgi

B.Sc. Computer Science M.Sc. Systems, Control and Mechatronics Engineering

B.Sc. Automation and mechatronics Engineering M.Sc. Systems, Control and Mechatronics Engineering

• •

Linkages Actuations

• •

Shutdown Circuit Wiring Connectors

Akshay Bharadwaj

Alexander Andersson

B.Sc. Electronics and Communications Engineering M.Sc. Systems, Control and Mechatronics Engineering

B.Sc. Computer Science

• •

DC-DC Converter BMS Slaveboards

BMS Software Sensors Software CFS18

Trainees The trainees are students studying their Bachelor and will help CFS during the year. They will train for maybe apply to CFS when they start their master studies. These students are a part of the team and have different responsibilities which they can focus on in order to do as much work as they want in their trainee time.

Simon Johansson

Birk Forsström

B.Sc. Mechanical Engineering



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Suspension



Suspension

Fredrik Lindelöw

Kristian Ivancic

B.Sc. Mechanical Engineering



Suspension

David Olsson

Oliver Ståhl

B.Sc. Computer Science

B.Sc. Mechanical Engineering



Low Voltage

Communications

Partner Relations The support is very important for us, as CFS would not be able to manufacture a vehicle with the same level of competitiveness. There are multiple events which CFS organize during the season and our partners are warmly welcomed to these events to learn about the progress of the project, give feedback and get to know the team. We thank our sponsors for a great season 2017 and hope for their continued support . We also wish you a Merry Christmas and a Happy New Year! Remember to follow us through different social media channels to keep up with what is happening with project and team members. Many movies and pictures from events and fairs are already uploaded!

@chalmersformula www.chalmersformulastudent.se

info@chalmersformulastudent.se CFS18