What lightweight object detection model would you recommend for persistent 3D object mapping on a Raspberry Pi 5?

I’m adding basic object recognition to my robotic lamp. It runs on a Raspberry Pi 5 and has an RGB-D camera in its moving head. I’d like to run object detection in the background while the lamp is active and gradually build a map of the objects around it. Since the base stays in place, I can calculate the camera pose from the joint angles. My plan is to combine detections from the RGB image with depth data, transform the object coordinates into the lamp’s base frame, and save their positions and last-seen time. Repeated detections would be merged so the map doesn’t fill up with copies of the s