Development of a Dynamic Electronic Speed Controller for Multicopters

The usage of unmanned civil and military drones is steadily rising. Essential components of every multicopter are its electric motors and the electronic speed controllers (ESC). These also determine, besides the flight dynamics and the stability behavior, the flight duration in a crucial way. Therefore in this contribution, an ESC for permanent magnet synchronous motors with a sinusoidal back electromotive force (PMSM) is presented, which was designed, under consideration of all these points. The basis for the precise and dynamic speed control is a high-resolution position sensor in combination with a 72MHz microcontroller. Under these circumstances, the speed control can operate at a high frequency of 20 kHz together with a high resolution. Using a field oriented control in combination with a flatness based control concept theoretically guarantees a maximum torque per ampere and thus a low energy consumption. The required speed signal is gained from the rotor position using a proportional integral observer. An exact asymptotic regulation is achieved implementing a state feedback integral controller.