Lidar Lite Integration
Project Scope
Working with another internal group on a project focused on vegetation and canopy height in rangelands. The group was looking for a way to quickly and accurately take cross-section height measurements in different testing plots. The goal was to collect both data on the ground as well as data from the UAV to compare speed vs accuracy. Below are the steps taken from initial idea to full drone integration.
Initial Testing
A breadboard setup was first used to test the code and insure recorded data was accurate enough for the project. After confirming data accuracy goals I 3D printed an adapter for a DJI Phantom 4 Pro v2. This allowed to to quickly get the lidar into the air and set various effects of attaching the device to a flying vehicle such as vibration, collected height accuracy and the willingness of the group to continue. The only downside of this approach is that there was no easy way to integrate the lidar data with the drone data. We had to depend on the DJI GPS to maintain a constant height above the ground. It was quickly determined we would need to fuse the lidar data into the drone telemetry data in order to get any time of accurate and repeatable data.
Following Steps
After proving out the first part of the project, we moved onto fusing the lidar data with drone telemetry. In order to do so we had to switch to a vehicle that allowed the user more access to such data from the drone. Following a few tutorials online, a wiring harness was created to integrate the lidar with an open source fight controller. We were now able to fly the drone and integrate data coming from both the drone and lidar easily.
Conclusion
Although we proved out it was possible to quickly and reliably collect data by fusing both lidar and drone telemetry data, the group concluded it would be cumbersome to go through the regulatory process of having researches gaining the required licensing to collect this type of data in the field due to FAA part 107 rules.
An alternative project route would have been to attach the lidar setup to some type of ground vehicle in order to both avoid the FAA drone regulations as well as have fixed distance from the ground to compare the lidar height to vs the vegetation height. This approach would be more time consuming vs the drone but again avoids the pitfalls of the above approach.