Update From The Battery Pack Team

Last Updated on Tuesday, 17 January 2012 13:34 Written by Mikkel Lauridsen Monday, 16 January 2012 00:03

Finding the right batteries is a very difficult task and it necessitates a lot of compromises during the process. In the mean time the concept for the battery pack has been worked out and is almost ready to adapt to the dimensions of the final batteries.

The concept

The battery pack consists basically of two parts; an inner part positioning all the batteries in small slots, and an outer shell securing the batteries against getting wet.

There are 24 slots in the inner cells and in total we estimate to use 6 of these cells giving us an amount of 288 batteries in total. The total amount of batteries can still be changed because we don’t know the exact batteries yet.

It has been decided to find out if it is possible to 3D print these inner cells. The advantages of 3D printing is that the design is very flexible according to change the dimensions for the batteries. Another advantage is that we are able to make an easy and simple way of assembling all the inner cells to each other.

The outer shell primarily has to protect the batteries against water. We can’t make it 100% sealed because we still need to circulate air for cooling the batteries. The idea is therefore to make an “overlapping system”, which allows air to circulate and still prevent water getting in.

Still need some changes!

The perfect racing seat

Last Updated on Tuesday, 17 January 2012 13:35 Written by Mikkel Lauridsen Wednesday, 04 January 2012 21:03

The idea for the seat on the Viking V, is that the seat and the firewall has to be combined. The reason for that is to save weight by having fewer parts as the seat and firewall will be in one part.

We thought about some different ideas, but ended up with choosing what we call the bucket seat, mostly because of the simple design and the possibility to make the seat by ourselves.

In Viking V, we want the driver to lay more down. The driving position should be more like that of formula one, where the alignment of the shoulder, knee and foot make a line.

We have made some models, to test what the best position is, one almost like that of a formula racing car, another with the head in a different position and the last with the legs more layed down.

We want to test the models on different people of different hights and sizes to see what seat made the best driving position.

The next thing is to draw the seat in a computerprogram. When the drawing is finished we can start making the first mold for the seat.

CANopen communication between node and motor inverter

Last Updated on Tuesday, 17 January 2012 13:38 Written by Mikkel Lauridsen Friday, 16 December 2011 10:04

This year the Viking racer is turned from a combustion to an electric race car and therefore a new engine control called an inverter is needed. Since the inverter has a CANopen interface and the current EPL network does not have this yet, it is necessary to implement a CANopen solution on this.

First of all the CAN-bus and the CANopen protocol have been investigated to find out how this works and what is needed to solve the problem described above.

After this investigation different solutions were considered. The first solution is to have an external chip which can take care of the CANopen interface, so the node can send and receive information through this chip. The second solution is to implement a CANopen ANCI C library directly on the node and hence only have the interface here.

The second solution is preferable, since the external chip is avoided. Having a CANopen implemented directly in software on the node will also be the solution that will be used on the later Viking racers.

Suspension Update

Last Updated on Tuesday, 17 January 2012 23:31 Written by Mads Grevit Thursday, 08 December 2011 14:45

The goals for the project are to develop the suspension for the Viking V. The project has several significant problems which have to be carefully considered and worked out to achieve the best driveability.

The parts which have to be developed and optimized are:

• Uprights

• A-arms

• Anti roll bar

These parts will be developed and optimized by calculations, simulations, tests and advices from experienced students.  

The parts that have to be chosen from suppliers:

• shock absorbers

• Springs

• Brake calibers and disc brakes

The most important goals are:

• To optimize the pick-up points so they fit better to the chassis. 

• Make steering less heavy – by e.g. changing the caster angle or changing the steering geometry.

• The camber angle should be easier to adjust due to different events

Status by November

The new A-arms (picture on the left) are designed and modelled in Pro/E and the final pick up points are decided. The kinematic analysis is almost done and will be finished by the end of week 48. The camber angle will be easier to adjust and the method of adjusting the camper is done by using small spacers at the top pick up point of the upright. This also requires a new type of uprights. These have been optimized and the design should be easier to fabricate and the part should be a little lighter(picture on the right). New types of bearings have been investigated caused some ware in the old bearings, because of the vibrations. An expert from Schaeffler Danmark ApS has given advices and the type of bearings will be decided within a few days.

Next step

The next step is to make the final kinematic analysis and document the behavior of the vehicle when driving. The calculations of the Center of Gravity for the car will be done as well.