The first version was built as a thesis project by me, Marcin Morawski and Dominik Wojtas. The first electronics was, of course, threading technology. There is a camera installed in it that allows point tracking, but it was homemade; for example, with a use of tree cutting machine etc. So the fish was not too lively, so to speak. But it was swimming. It was equipped with a swim bladder. It had all these basic essentials. The next version already emerged in SMT. It was the lightest (1.6 kg), the most agile fish with magnetic switching. All tests on the robot were run in a pool in Skawina, so that everyone could come - they like it. And that also allowed us to have a better access to the pool. As you can see, it swims pretty fast. A new design of swim bladder was used, in comparison to the first one. And starting with that second fish we work only in a team of two, me and Marcin Morawski.

The third version was built in cooperation with the Naval Academy. It was made with a use of Rapid Prototyping Technology, which is a simulator presenting the floating. An interesting thing is VN-100 sensor installed in it. This is a type of IMU sensors (Inertial measurement unit) and it measures all the parameters of motion: an angular position, accelerations, magnetic field in three axes; the system is additionally equipped with sensors for barriers’ detection. This approach, of course, works only in the laboratorial conditions - in pure water. But here, especially on this video, we see the advantages of the robot. It swims in the wall direction on the full speed. And here you see that right before the wall it avoids a collision. On this fragment the way the VN-100 sensor works can be seen. And here again it is shown how the robot moves in the water. It will now immerse by changing the angular setting of the side fins. It will dive, and then it will use only its swim bladder for emersion, changing its buoyancy like a real fish.

The fourth version is already much more advanced. Mathematics was used. A lot of things were taken from the literature, because similar constructions are created in the world. In Poland we are the only ones who deal with that. In Europe there are two or three centers where they do it as well.

This fish is also more advanced in terms of its operating - independent tail fins, a body is made of plastic P500. It has plugged one segment more than before; it weighs more than 6 kg. The interesting thing about this construction is PC104+ which is a much more advanced control system. It has static pressure sensors, dynamic pressure sensors, prepared slot for HD camera.

I am continuously improving the control system, so to speak. At this moment the control system in the fourth fish is finished, but we aim to make it an autonomous robot. Marcin Morawski’s disease, unfortunately, did not allow us to continue our work at the same level.