We are trying to implement autonomous indoor flying with the Pelican Quadrotor and ROS. We are using the asctec_mav_framework. We added a 360° 2D-laser range scanner to the UAV as well as a 1D laser range scanner for measuring the height above ground. With those two devices, we can obtain a pose (x,y,z,yaw) and can use the HL position controller. However, as the 2d laser scanner has a limited range, it can happen, that there are no objects visible to measure the position in the 2d plane of the robot.
In this case, we are missing a position input to the HL position controller and would like to hover at the current position. We hoped that this can be achieved using the onboard imu. However, the UAV starts drifting heavily in this situation, accelerating to high speed in very little time.
My question is: is it possible, to stabilize the UAV using only the 1D height laser and onboard IMU with the position controller? As we added sensors to the quadrotor, would we need to make changes to the internal model? If so, how can this be achieved?
Re: Hovering in HL position control mode - huge drift
Hi, I do not think it is possible to perform 3D position control using just a height sensor and IMU. You can use external motion tracking systems like the VICON, or you can install cameras. You can do position control using the PTAM algorithm