OskysWork
New Member
- Joined
- Jun 28, 2023
- Messages
- 2
- Reaction score
- 0
After struggling to find any good resources / starting points on the topic of thrust vector control on rockets, I have come to r/modelrocketry in hopes of any advice and help possible!
Firstly, in order to determine the rocket's attitude from an IMU containing both gyroscopes and accelerometers, some sort of filter is required due to the gyroscpoe's drift and there being no 1g reference for the accelerometers (as the rocket itself is accelerating). From what I understand, a Kalman filter is a potential solution, albeit quite complicated, but is something along the lines of an arduino powerful enough to run a Kalman filter real time anyway? Alternatively there's something called a Madgwick filter which is more computationally efficient; however, it seems to be less precise and less flexible. Which would be more appropriate for a model rocket?
For whichever is the most appropriate, what are some good resources to understand and implement the filter? I have found some books (online pdfs) on the Kalman filter, but I don't know which sections are relevant to the application of attitude estimation of an accelerating rocket. Additionally, from my very basic fundamental understanding; it requires equations of motion that take into account the variation in thrust of the rocket, the resultant torque from each gimbal movement, the drag profile of the rocket, etc... But doesn't this create a "What came first? The chicken or the egg" senario? I need to know the attitude of the rocket to angle the TVC mount accordingly, but to know the attitude I also need to know the angle of the TVC mount?
Thank you for taking the time to read this post / my confusion! Any resources on understanding how best to tacle the problem is much appreciated, I want to put in the work but currently am unsure of which direction to put it in.
Oscar
Firstly, in order to determine the rocket's attitude from an IMU containing both gyroscopes and accelerometers, some sort of filter is required due to the gyroscpoe's drift and there being no 1g reference for the accelerometers (as the rocket itself is accelerating). From what I understand, a Kalman filter is a potential solution, albeit quite complicated, but is something along the lines of an arduino powerful enough to run a Kalman filter real time anyway? Alternatively there's something called a Madgwick filter which is more computationally efficient; however, it seems to be less precise and less flexible. Which would be more appropriate for a model rocket?
For whichever is the most appropriate, what are some good resources to understand and implement the filter? I have found some books (online pdfs) on the Kalman filter, but I don't know which sections are relevant to the application of attitude estimation of an accelerating rocket. Additionally, from my very basic fundamental understanding; it requires equations of motion that take into account the variation in thrust of the rocket, the resultant torque from each gimbal movement, the drag profile of the rocket, etc... But doesn't this create a "What came first? The chicken or the egg" senario? I need to know the attitude of the rocket to angle the TVC mount accordingly, but to know the attitude I also need to know the angle of the TVC mount?
Thank you for taking the time to read this post / my confusion! Any resources on understanding how best to tacle the problem is much appreciated, I want to put in the work but currently am unsure of which direction to put it in.
Oscar