TY - JOUR N2 - The paper presents the results of simulations and experiments in the field of control of the low damping and time delay oscillating system. This system includes a quadcopter hovering at a very low altitude, and the altitude is controlled. The time delay is introduced mainly by the remote control device. In order to handle the quadcopter at low altitudes, a proportional-integral controller with a negative proportional coefficient is used. Such an approach can provide good results in the case of an oscillating, low damped system. This method of steering, which uses a typical radio control transmitter, can be used on any commercially available leisure drone. Feedback is provided by a camera and algorithms of computer vision. The presented results were obtained experimentally using free flight – without a harness. Different types of controllers are used to control horizontal shift and altitude. L1 - http://journals.pan.pl/Content/121565/PDF/art08.pdf L2 - http://journals.pan.pl/Content/121565 PY - 2021 IS - No 4 EP - 858 DO - 10.24425/aee.2021.138265 KW - control KW - estimation KW - ground effect KW - visual servoing A1 - Urbański, Konrad PB - Polish Academy of Sciences VL - vol. 70 DA - 2021.11.30 T1 - Low altitude control for quadcopter using visual feedback SP - 845 UR - http://journals.pan.pl/dlibra/publication/edition/121565 T2 - Archives of Electrical Engineering ER -