This week, I focused on picking out hardware for the design and thinking through an interesting design problem that has already arose.
On the hardware side, I settled on an integrated IMU, magnetometer, and barometer module and a GNSS module to be connected on an I2C bus to the Raspberry Pi. The Raspberry Pi was chosen to have 8GB memory, which should be sufficient for the software tasks we’re planning to run onboard. I chose an IMX477 camera for the visual perception, as it’s similar to the camera used in the paper we are referencing.
Since our current plan is to have the camera rotating on the module, we need to know the relative angle between the camera and the module in order to fuse IMU data with the visual camera position fixes. In fact, the visual fixes could theoretically produce an accurate heading fix, but it is useless if we do not know the relative angle between the visually perceived heading and the drone. To this effect, I considered mounting the camera on a stepper motor with an encoder, though this is vulnerable to backlash and encoder quantization drift. I am currently exploring the possibility of having small fiducials along the periphery of the camera rotation hardware that the camera could track its angle relative to, and thus know its angle relative to the drone.
Separately, I am working on preparing the design review presentation.