I study at the TU/e in the master science and technology of nuclear fusion but because I already have a master in electromechanical engineering, I wanted to continue learning about control engineering. Therefore I talked with DIFFER for an internship and they delivered. I also wanted to go to Japan since I did karate and that country fascinates me. DIFFER gave me a project named: “Non-linear optimal controller for Wiener systems using the Hamilton-Jacobi equation for exhaust control”. I went to Nanzan university in Nagoya since the professor (N. Sakamoto) who does research in the stable manifold theorem for non-linear control works there. The university does not have an affiliation with nuclear fusion, but they have a control engineering department. N. Sakamoto himself is a mathematician and aerospace engineer who works in the field of control engineering.

The goal of my project was to make a non-linear optimal controller for the fueling (and seeding) in the divertor with the stable manifold approach (which uses the Hamilton-Jacobi equation) to control the power that hits the target plates.

I started out with learning about optimal control and non-linear control since I did not had a course about it yet. After that I started to learn about the already existing Matlab code for the divertor exhaust from DIFFER and how I could make a controller. The model was simplified for me since I didn’t have much experience with this model or the control needed. I started out with making a LQR controller to see if that approach works. When I succeeded in doing that, I started to work to make a controller via the stable manifold approach with the use of research done and Matlab code by N. Sakamoto.

I learned a lot in this internship since I didn’t know at the start how to do optimal or non-linear control. However I would have liked to have done a bit more so that I would have more results.

Besides doing my internship, I also visited different places in Japan such as Tokyo, Osaka, Kyoto... Japan has a very kind, clean and respectful culture and I loved visiting nature and religious sites such as shrines and temples. However the people in Japan usually don’t speak any English so it can be quite difficult to communicate. I also saw that Japanese people are quite shy to members of the opposite gender and thus you see (specially in universities), clusters of woman and men separately. Generally the behavior of Japanese people towards people of the opposite gender is quite different then when they react with people of the same gender. It was weird to be part of that as a person from Europe.