Height control of a quadrotor when voltage of battery falls

In this paper, a switching type PID controller is proposed in order to eliminate the static error as the voltage of the battery goes low in a real UAV system. In the switching type PID controller, the Integration Control is put in based on the differential of height which means vertical speed. Simulation of conventional PID and switching type PID control is presented. Real-time experiments show that the switching type PID controller is able to make the UAV track the desired height quickly and precisely.