Hello,
- Which onboard localization and navigation capabilities are available for autonomous flight without GNSS? -> The starling 2 max uses openvins for localization, and we would encourage you to use april tag relocalization in order to navigate around indoor environments as openvins can drift over time.
- How reliable is visual-inertial localization in repetitive greenhouse rows with limited visual features? -> This is tough to be deterministic BUT, cant expect 2% error over distance. Greenhouse rows reminds us of the SAVLoc from Micheal Baldwin (presented at the PX4 dev summit): https://www.youtube.com/watch?v=9wk9_TNN1DA. This is not something that is present natively on the VOXL but presents an interesting localization technique indoors that you can utilize.
- Can the platform execute predefined and repeatable trajectories without GPS? -> yes, but again we would recommend utilizing the april tags for relocalization as there is some error over distance. you can also utilize mavsdk in order to put the drone in offboard mode and control trajectories. You can find that documentation here: https://docs.modalai.com/mavsdk/
- What software components, SDKs, or additional development are required to implement those trajectories? -> refer to answer in last question
- Which onboard sensors are used for obstacle detection and avoidance, and what limitations should we consider around thin wires, foliage, and greenhouse structures? -> TOF module as well as tflite and opencv for computer vision. There is a collision prevention module inside PX4 that will prevent the drone from flying into something in position flight mode. You obviously have already used voxl-mapper. Anything higher level you can program in yourself in our ROS 2 plugin
- Does ModalAI have documentation or examples for autonomous indoor waypoint navigation using Starling 2 Max? -> currently mainly the voxl-mapper. There are some custom projects that Ascend Engineering has worked on to do this
- What safety measures and fallback behaviors are recommended if localization becomes unreliable? -> Would recommend flying in a netted & controlled area that is separate from humans. Also, have a remote control that you can switch back into manual control in order to take manual control of the drone if you feel localization is becoming unstable
