The Orbserve: a unique graduate research project
Since the beginning of the invention in the 20st century, unmanned aerial vehicles – also known as UAV’s or drones – have become very popular in the field of aerospace. Both the business and private market have experienced a growth in the development of all kind of drones, such as quadcopters. One of the most important issues considering UAV’s and drones is related to safety. Due to its weight and size, unexpected and uncontrolled descend can lead to serious damage and is even threatening to people’s lives. This often-discussed topic formed the starting point of the research project of Fabien Bruning. He started two years ago as an graduate intern at TMC and developed an embedded control design for a finless airship with actuator dynamics, called the “Orbserve”.
To Fabien the aviation has always been a very fascinating work field. That’s why he decided to do a minor in Aerospace Engineering at the Queen Mary University in London during his Bachelor in Mechanical Engineering and obtained a gliders pilot license. After that he completed a Master in Control Systems Technology. During his graduation Fabien came in contact with TMC Employeneur Luc Houben, who had just started a project in the field of safety of drones. This project formed the basis of Fabien’s research project. ‘The entrepreneurial vision of TMC and the opportunity to develop something entirely new appealed to me directly,’ Fabien tells. ‘Though TMC is not a research centre, TU/e still gave me the permission to start on this unique project in which I focused on the control of an unmanned spherical airship designed for low-speed and low-altitude operation.’
‘When I started the project, Luc had already made a concept hardware design. This consists of a 2.5m helium balloon with four vectoring thrusters, located at 90° intervals along its periphery. One of my first steps was the sensor and actuator selection, and after that the electronic and software architecture. Compared to a traditional zeppelin, this allows the UAV to move immediately in any direction, much like a helicopter or quadcopter. The vision was to create a camera platform that moves the shot freely, as if it was floating in space. After that we created a model using the frequency response of the actuators, build a full prototype and proposed a control allocation strategy for the over-actuated system. The prototype – which we called the Orbserve, a combination between observing and the round model – was tested inside the Applied Micro Electronics (AME) and the PSV Stadion. This learned that the system stability and safety were good, however the flight duration was less than desired due to the larger than simulated amount of thrust required to deal with wind disturbances. Unfortunately it was too difficult to get funding to design a new model to improve this and therefore we had to put a stop to the project. Although we didn’t end up with the ultimate result, I’m still very proud of what we have realized with the Orbserve. We developed and created a prototype for a completely new type of aerial vehicle in a relatively short period, which could be revisited when advances in battery technology arrive. We have calculated for example that with certain prototype fuel cells, the flight duration will change from half an hour to several hours. With this I believe we have made a breakthrough in the technology of UAV’s!’
New knowledge and skills
After finishing his research project and obtaining his masters degree, Fabien got offered a job at TMC. ‘After some interesting projects at the Entrepreneurial Lab and ASML I started working at TNO. Here I’m involved in several projects considering the control engineering and implementation of the mechatronics at the Equipment for Additive Manufacturing department. One of the projects I’m working on is the Lepus Next Gen, a new SLA printer developed at TNO. SLA printers work by depositing resin, and selectively curing this resin in order to create a 3D structure. The unique advantage of the Lepus Next Gen is the combination of a new modular light engine, which delivers accurate projection with 20-micron pixels. Since it is modular, its size can easily be increased without losing resolution or speed. Furthermore, due to its top down approach, it is extremely suited to multimaterial and integrated electronics applications. I’m very excited with the chance to work on projects like this and learn a lot form the dynamic work environment. Moreover I’m very happy with what I’ve learned from the Orbserve and the fact that I’ve participated in a full product life cycle project. It has helped me to gain new knowledge and skills in the field of embedded control design and I still benefit from this experience every day!’