Test platform to pitch angle using hardware in loop

Abstract

The low cost electronic component and sensors makes the development of UAVs (Unmanned Aerial Vehicles) more accessible. Consequently, more students are interested in the skills necessary to integrate an UAV developing group. A very important component in a UAV is the automatic pilot. Aiming Education and Research in Digital Automatic Pilot development a flexible system to test flight controllers is proposed. The system uses the structure known as ¿hardware in the loop¿ in which the aircraft model is simulated in a PC (Personal Computer) and the designed controller is implemented in a microcontroller. The proposed system is appropriate to be used in laboratory classes in which the students can test the controllers previously designed using control theory and can also practice the use of interfacing devices, necessary to convert the analog signals provided by the sensors to the digital form used by the processors, and communication devices, necessary to the information exchange between the PC and the microcontroller. The laboratory practice is such that the student can compare the results obtained using the conventional simulation approach, in which a control loop consisted of the designed controller and the aircraft model transfer function is simulated in a computer, and the results obtained using the proposed platform. Implementing the designed controller in a microcontroller that can be embedded in an UAV exposes the student to a more real situation, considering also the possible delays between a command given by the controller and the change of a parameter in the aircraft. The results presented here were obtained implementing a PID (Proportional, Integral and Derivative) controller in a microcontroller and doing all the connections necessary to a PC implementing a longitudinal motion model of an aircraft.