Towards Autonomous Navigation for Nano-Blimps
In recent years the popularity of unmanned aerial vehicles (UAVs) has soared. The most common type of UAV, the quadcopter, requires a large amount of energy to create lift and stay in the air. For this reason, it suffers from very large charging times and very short flight times. As an alternative, in the previous project of this series we introduced another type of UAV: a blimp. We demonstrated that, thanks to the helium-filled balloon, the energy requirement for hovering is significantly reduced. In this project we aim to extend the functionality of our first self-sustainable blimp prototype.
The main goal of this semester thesis is to extend the existing self-sustainable blimp developed at TIK/IIS and presented in . In our previous project , we explored the energy requirements of hovering blimps for self-sustainability. In addition, we studied how different power management techniques, namely continuous power and duty-cycling, differ in terms of their service level and lifetime. The former can achieve hovering with a relatively small deviation from the desired altitude, at the price of higher power consumption. The latter reduces the average power consumption and leads to longer flight times, but demands a larger tolerance to the desired altitude.
In this project we first aim to extend hovering by introducing horizontal movement, thus creating a blimp that is able to move in three dimensions. Such a prototype is ideal for developing more complex autonomous navigation. In addition to movement, we also aim to expand the on-board processing capabilities with visual sensors. To this end, the second task of this thesis is to incorporate, optimize, and possibly improve an existing state-of-the-art algorithm  for autonomous flying nano-size UAVs. Practically speaking, the mandatory goals of the project can be summarized as follows:
- Starting from the first prototype, develop a helium-based, remote controllable blimp able to perform vertical and horizontal movements.
- Adapt freeRTOS to control the blimp.
- Extend the blimp with an on-board camera, as done in .
- Adapt the red-based object tracker presented in  to control the motion of the blimp.
Optional tasks that can be addressed after all mandatory tasks are done, and these are:
- Implement a streaming task on the blimp in order to collect on the base-station (e.g., laptop connected via the crazyRadio) the camera frames paired with inertial information.
- Evaluate the feasibly of, and possibly implement, an alternative 3D translation mechanism that uses only 2 motors for both vertical and horizontal movements. The key idea is to introduce a small additional motor to dynamically adjust the motors' thrust angle.
- Familiarity with embedded system programming in C.
- Basic knowledge of FreeRTOS  and STM32F4 MCU family  is favorable.
- 25% Theory
- 25% Study of existing systems
- 30% C embedded programming
- 20% Verification and experimental evaluation
Detailed Task Description
Meetings & Presentations
The student(s) and advisor(s) agree on weekly meetings to discuss all relevant decisions and decide on how to proceed. Of course, additional meetings can be organized to address urgent issues.
 Bitcraze Crazyflie2.0 http://www.bitcraze.io/crazyflie-2/
 D. Palossi et Al., "Target following on nano-scale unmanned aerial vehicles." In 2017 7th IEEE International Workshop on Advances in Sensors and Interfaces (IWASI), pages 170–175, June 2017.
 D. Palossi et Al., "Self-sustainability in nano unmanned aerial vehicles: A blimp case study." In Proceedings of the Computing Frontiers Conference, CF’17, pages 79–88, New York, NY, USA, 2017.
 Free RTOS http://www.freertos.org/
 STM32F405/7 http://www.st.com/resource/en/datasheet/stm32f405og.pdf