Jacob Snyder | University of Iowa
Marshall Space Flight Center | May 30 – August 4, 2017
WHAT WERE THE GOALS OF THE PROJECT?
The goal for this project was to install a more precise gyroscope onto an existing hardware system that is in the process of being updated using the 9-axis absolute orientation sensor. The 9-axis absolute orientation sensor is equipped to measure the orientation of the structure it is mounted to through the processing of data acquired by an onboard accelerometer, gyroscope, and magnetometer. Gathering such information will relieve the Advanced Microwave Precipitation Radiometer (AMPR) instrument from the dependency on an aircraft’s onboard inertial navigation system (INS) for orientation data. Data collected by AMPR currently relies on the orientation measurements of the INS when registering the data to generate a 3-dimensional view of storms. Typically, the INS of an aircraft is not located at the position of AMPR when installed on the aircraft. This can lead to errors in the true orientation of AMPR in flight arising from the aircraft’s orientation being based on the location of the INS. The installation of the 9-axis absolute orientation sensor into the AMPR instrument will allow collecting a more accurate representation of the orientation of the instrument itself. This will mitigate errors in registration arising from the differing locations of the INS and AMPR. Through analyzing the differences in measurements made by the aircraft’s INS and the absolute orientation sensor on AMPR, it is possible to retroactively correct errors in data from previous missions that were flown without AMPR’s onboard orientation sensor.
DESCRIBE WHAT YOU DID DURING THE THE INTERNSHIP.
My tasks primarily revolved around the hardware and software involving the orientation sensor. I read through the datasheets and hardware specifications for the sensor and peripheral integrated controller (PIC) used in the board. I worked closely with Dr. Herb Sims to verify that the desired functions performed by the board were fully implemented and implemented correctly. I also was able to aid in the assembly of the new flight chassis being used on the AMPR instrument. Once the orientation sensor was integrated into the circuit, I was then tasked with working on the serial communications between the PIC and the flight computer housed in the flight chassis. This involved studying previous commands used and modeling the new commands from there. I was not able to finish testing the commands due to some setbacks in the design of the flight chassis and connections required to use the serial commands, but an iteration of the design and functions to handle the messages was in place.
WHAT WERE YOUR RESULTS AND CONCLUSIONS?
Overall the project was a success in that the sensor was fully integrated into the board being installed in the AMPR instrument. The BNO055 intelligent absolute orientation sensor will be a beneficial addition to the AMPR instrument in future missions. The orientation data that it can collect will prove useful in eliminating the errors that arise from the differences in location of the aircraft’s INS. Using the I2C protocol allowed the pin demands on the PIC to remain small while still having the capacity to handle a large amount of data transfer.
The next steps in the project involve installing the board into the instruments onboard flight computer. The BNO055’s board along with several others will be encased in a chassis to be mounted onto the AMPR instrument. In the future, further testing will be required to ensure that the UART commands are functioning as expected. Once those commands have been fully implemented the system should be able relay the orientation data to the flight computer for recording.
WHAT LESSONS DID YOU LEARN THROUGHOUT THE PROCESS?
From this experience I learned a number of important lessons. I learned the importance of rechecking previous work. We all can make mistakes and that sometimes it just takes a fresh set of eyes and a few questions to catch a problem that was overlooked by others. Teamwork plays an important part in projects like these as well. Some of the work being done at MSFC has been going on for months or years prior to joining their team, so it is important to work with others to help gain an understanding as to why or how something was done. Overall, working with the people at the MSFC was a very rewarding experience and I am very grateful for having the opportunity to do so.