Raais
Member
- Joined
- Aug 27, 2020
- Messages
- 10
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Greetings,
Over the past few weeks, I've been exploring the various aspects of developing an avionics system capable of taking measurements and deploying parachutes. I am particularly interested in constructing my own flight computer, although my experience in electronics has never been applied to a rocketry project.
After studying a bit and checking different points of views of people that seems to have expireience on the field, I believe I have a relatively clear grasp of the fundamentals. My plan is to develop a flight computer primarily equipped with a barometer and a 6DOF IMU with a high-g accelerometer, alongside a GPS. For deployment control, I intend to primarily rely on barometric altitude readings, integrating IMU acceleration to get vertical velocity and prevent unintended deployments during the mach transition zone. While I'm uncertain if this is the most optimal approach, my research suggests multiple options, with this one appearing to be a reasonable choice.
However, the real problem for me lies in the aspect of measurement filtering. I've never worked with signal filtering, and I must admit, I'm a bit overwhelmed. I understand that implementing a Kalman filter to accurately process IMU measurements is essential, even though it's not an easy task. Nevertheless, I don't have the same level of certainty when it comes to the altimeter. Some suggest a simple low-pass filter, yet I'm unsure whether it should be a FIR, an IIR or something else. Others propose a moving average, while some recommend a basic Kalman filter solely based on barometric readings. I recognize that the ideal approach would involve fusing both the IMU and the barometer data with a Kalman filter. However, lacking experience, I'm unsure about going with this option, especially now that I am getting into this. Thus, I would greatly appreciate your recommendations or any advice on how you would approach this.
Apart from this, I would like to ask what temperature you use to determine altitude. I have read that sometimes the barometer inbuild sensor temperature is used (I plan to use a MS5607 barometer), but I am unsure how advisable this is, as the avionics module tends to be at a higher temperature, and the sensor is not exceptionally accurate. Others suggest using a constant temperature of 15 degrees. What would you recommend?
Considering everything mentioned, I would greatly appreciate your insights and approach to handling these matters. Any information you can provide would be highly valuable to me.
And of course, thank you in advance!
Over the past few weeks, I've been exploring the various aspects of developing an avionics system capable of taking measurements and deploying parachutes. I am particularly interested in constructing my own flight computer, although my experience in electronics has never been applied to a rocketry project.
After studying a bit and checking different points of views of people that seems to have expireience on the field, I believe I have a relatively clear grasp of the fundamentals. My plan is to develop a flight computer primarily equipped with a barometer and a 6DOF IMU with a high-g accelerometer, alongside a GPS. For deployment control, I intend to primarily rely on barometric altitude readings, integrating IMU acceleration to get vertical velocity and prevent unintended deployments during the mach transition zone. While I'm uncertain if this is the most optimal approach, my research suggests multiple options, with this one appearing to be a reasonable choice.
However, the real problem for me lies in the aspect of measurement filtering. I've never worked with signal filtering, and I must admit, I'm a bit overwhelmed. I understand that implementing a Kalman filter to accurately process IMU measurements is essential, even though it's not an easy task. Nevertheless, I don't have the same level of certainty when it comes to the altimeter. Some suggest a simple low-pass filter, yet I'm unsure whether it should be a FIR, an IIR or something else. Others propose a moving average, while some recommend a basic Kalman filter solely based on barometric readings. I recognize that the ideal approach would involve fusing both the IMU and the barometer data with a Kalman filter. However, lacking experience, I'm unsure about going with this option, especially now that I am getting into this. Thus, I would greatly appreciate your recommendations or any advice on how you would approach this.
Apart from this, I would like to ask what temperature you use to determine altitude. I have read that sometimes the barometer inbuild sensor temperature is used (I plan to use a MS5607 barometer), but I am unsure how advisable this is, as the avionics module tends to be at a higher temperature, and the sensor is not exceptionally accurate. Others suggest using a constant temperature of 15 degrees. What would you recommend?
Considering everything mentioned, I would greatly appreciate your insights and approach to handling these matters. Any information you can provide would be highly valuable to me.
And of course, thank you in advance!