Hello, my name is Marco Geurtsen and I am an Electrical Engineer in the DARE Advanced Control Team. In this blog, I will inform you about the recent activities within the ACT and DARE. The DARE society is on the edge of launching its largest project in the history of student rocketry. In October 2015, the Stratos II+ will be launched from Spain and set course to the sky. Stratos II+ contains several scientific payloads from organisations such as the Radboud University of Nijmegen. My colleagues from the Advanced Control Team are actively involved in developing a detailed simulation program which models the trajectory of Stratos II+, which shall also be used for simulating the ACT’s actively stabilized rocket. However, until recently the team did not produce any hardware for Stratos II+.That has changed over the past months.

I am working on an attitude determination system for DARE’s first actively stabilized rocket the V7S, which will be launched in November 2015. Its Flight Computer has a variety of sensors which determine the acceleration, rotation, and altitude of the rocket. The main sensor of this system is the Inertial Measurement Unit (IMU). Together with the team I am continuously improving the Flight Computer, increasing its accuracy and logging frequency, and experimenting with new types of IMUs.

Not a long time ago, we acquired the most advanced IMU DARE has ever seen. The ACT partnered up with with XSENS “the leading innovator in 3D motion tracking technology”, where we received a MTi-100 IMU which we will test with the launch of Stratos II+. For the attitude determination the ACT requires an IMU which has a high accuracy with as little drift as possible, while being able to withstand high accelerations. Stratos II+ has the perfect flight profile to test such an advanced sensor. The previous IMUs did not always fulfill these tough requirements, especially when it comes to sensor accuracy and data logging frequency. The ACT was determined to push the performance of the Flight Computer to its limits, and therefore we needed to find a top-level IMU. For this the team contacted XSENS, since they offer high quality sensors for student projects.

XSENS MTi-100 IMU

I am developing a payload module together with Nick van den Dungen, Team Leader and Structures Engineer of the ACT, which will be launched with Stratos II+ in October. The XSENS MTi-100 IMU is the key element of this payload module, since it shall continuously log data during the flight. This data is then stored onto a Black Box, which we will retrieve after a successful flight of the Stratos II+. The entire module is supported by shock absorbers to minimize the vibrational effects of the rocket on the sensors. The payload module is situated in the Stratos II+ payload bay inside the nose-cone of the rocket, together with the other experimental research payload modules. The data of the IMU will be processed to determine its behavior during flight, and to identify the level of noise the IMU will produce in-flight. This data is then compared with the simulations to investigate the accuracy of both the IMU and the by the ACT developed simulation tool.

CAD drawing of ACT Stratos Payload Module, with XENS MTi-100 IMU

The research done on the ACT Stratos Payload Module with the XSENS MTi-100 IMU is the baseline for future ACT Flight Computers which have an increased performance, hence increasing the efficiency of rocket attitude determination methods within DARE.