Optoelectronics of Non-Contact Method to Investigate Propeller Rotation Speed Measurement of Quadrotor Helicopter

The measurement of propeller speed of a quadrotor helicopter is very useful to estimate its thrust force. The infrared light on the optoelectronics method is used to detect the existence of the propeller by non-contact technique for avoiding friction and loss. The phototransistor is applied as a sensor then the data signal is processed by voltage comparator and microcontroller. The objective of this research is to investigate the rotation speed of propeller measurement quadrotor helicopter by optoelectronic of non-contact technique. The measurement results indicated that the propeller rotation increased non-linearly to the time. Therefore, the speed of the propeller fluctuates dramatically, which may be caused by noise and disturbance of sensor, counting error of microcontroller also the non-linearity characteristic of DC motor as the rotor. The measurement uncertainty tends to be larger at a higher speed. Because of these circumstances, many data samples are required to estimate the actual value of propeller speed measurement exactly. In addition, these nonlinearities should be taken into account to control thrust force for hovering properly the quadrotor helicopter.