Engineering Experience 4: Design a Small Solar Vehicle/Nl/2014: Team AM6

introduction
This Wikipage is about 5 students, named Team Sunergy, from the KULeuven @ Group T who have been given the assignment to model and build a small solar vehicle (SSV). At the end of the semester there will be a challenge where we have to compete with the other teams of students. In this challenge we have to get a petanque ball as high as possible after hitting it with our SSV.

Blog
Here we will write an update about the events each week.

Week 1
During this week we had the first seminar. At this seminar we received an explanation about the project and what was expected from us. We received a first deadline (Friday 14/2), where several documents had to be finished to get started. These were the cooperation contract, the plan of approach, the work breakdown structure and the gantt chart. We divided the work and the documents were finished without any problems.

Week 2
This week we had a seminar about the solar panel and the DC-motor which will power the SSV. Afterwards we ran tests on the solar panel to receive more information about the power it supplies. In these tests we linked a variable resistor to the solar panel, measuring the current flowing through and voltage across the resistor. We repeated this multiple times, every time with different values. With these values we were able to determine the optimal working point of the solar panel.

Week 3
The seminar of week three was about race strategy. We were given information about how we should determine certain variables. This and the coming weeks we will be using an analytical approach as well as Matlab to do calculations and simulations to decide some characteristics of the SSV like the gear transmission ratio and the total weight of the vehicle.

Week 4
This week we were given an explanation about simulink, an application which gives the possibility to simulate the behavior of certain objects. For example a connection of a solar cell with a resistor. It is also possible to simulate a larger part of the SSV up to the link between the electrical part and the mechanical part.

Week 5
For this week's seminar the leader of FabLab Leuven gave an explanation about FabLab. He explained the general purpose as well as details about which machines are there to use and how/when to use them. This week we continued to work on the analytical approach, Matlab and Simulink.

Week 6
This Friday, we had a deadline for the first two cases. The Simulink case as well as the case SSV, part 1 had to be handed in. Both these cases were designed to determine the optimal mass and the optimal gear ratio for our small solar vehicle in order for the ball to go as high as possible. For the mass, for example, it is finding a balance between reaching a high speed when hitting the ball and hitting the ball with a high enough mass so that the energy can be transferred efficiently. The Simulink case went pretty well, there were no big problems here. The case SSV part 1 includes an analytic approach as well as simulating the behavior of the SSV using Matlab. After quite a lot of labor, the analytic calculations were completed. The Matlab part went not as fluent as the other two. Since we hadn't worked with Matlab before, it was not easy to find solutions to the many errors that came up at the first try. After a lot of searching and a few meetings with our coach, we finally were able to make it run the way we wanted it to run. Afterwards it felt pretty good that both the cases were finished and the reports were delivered in time.

Week 7
This week we received (positive) feedback from our coach about the Simulink case and the case SSV part 1. After this feedback we came together to discuss the next case, more in particular how we would handle it. We did some research on how our SSV should be built.

Week 8
On Tuesday we had a test about the first part of the project and about technical drawing. Afterwards, we discussed some more about the parts for our SSV. We also set a date for our next appointment during the Easter holidays.

Easter break
During the Easter break we made sure all the parts were made and ordered so we could make sure the SSV was ready to test the Tuesday after the break. Because we ordered several parts, we had the wait almost 2 weeks before we could start building

Week 9
On Monday we finished working on the SSV so we could test it the day after. When we were done, the SSV was able to drive powered by a battery. Tuesday there was a possibility to run tests regarding the impact on the SSV during collision. Everything went quite well during the tests.

Week 10
This week, we optimized the SSV. After some tests, we encountered several problems: We saw that the wood of the frame was nog strong enough to withstand the impacT. To solve this, we mounted a metal plate in the front. With this metal plate, we will hit the ball.

Week 11
This was a very stressed week for us. On Friday we had the deadline for Case SSV 2 and we still had some work to do. We also encountered some new problems with the SSV axle. Suddenly it nearly could turn, which is off course a major problem. We solved it by making the holes of the motor holder bigger where the axle go trough.

Finished SSV


The finished SSV has the following features:


 * Metal front plate: First we pushed the ball with the wooden front of are frame. After a few collisions and after the strength calculation, we saw the the wood was not strong enough. We solved this by mounting a metal plate af the front.
 * Switch: This was just logical to add. Because of the switch we able to turn of the SSV immediately after the collision to prevent further damage.
 * GPS holder with sucker: We chose for a GPS holder to mount the solar panel. This was a very easy way, but very good solution. The arm can be turned in every direction, so the solar panel will always be directed to the sun for optimal working.
 * Hard rubber wheels: We chose for this wheels for maximal traction. Also, these wheels are 2cm wide. Therefore, the SSV is very stable.

Orientation phase
Cooperation contract: https://www.dropbox.com/s/yf16lsdqe3vb8pv/Cooperation%20Contract.docx

Analysis phase
Plan of approach

Work Breakdown Structure

Gantt Chart

Implementation phase
Case SSV part 1

Case SSV part 2

Case Simulink

Process report