Simulation and flight experiments of a quadrotor tail-sitter vertical take-off and landing unmanned aerial vehicle with wide flight envelope

Abstract

This paper presents the modeling, simulation, and control of a small-scale electric powered quadrotor tail-sitter vertical take-off and landing unmanned aerial vehicle. In the modeling part, a full attitude wind tunnel test is performed on the full-scale unmanned aerial vehicle to capture its aerodynamics over the flight envelope. To accurately capture the degradation of motor thrust and torque at the presence of the forward speed, a wind tunnel test on the motor and propeller is also carried out. The extensive wind tunnel tests, when combined with the unmanned aerial vehicle kinematics model, dynamics model and other practical constraints such as motor saturation and delay, lead to a complete flight simulator that can accurately reveal the actual aircraft dynamics as verified by actual flight experiments. Based on the developed model, a unified attitude controller and a stable transition controller are designed and verified. Both simulation and experiments show that the developed attitude controller can stabilize the unmanned aerial vehicle attitude over the entire flight envelope and the transition controller can successfully transit the unmanned aerial vehicle from vertical flight to level flight with negligible altitude dropping, a common and fundamental challenge for tail-sitter vertical take-off and landing aircrafts. Finally, when supplied with the designed controller, the tail-sitter unmanned aerial vehicle can achieve a wide flight speed envelope ranging from stationary hovering to fast level flight. This feature dramatically distinguishes our aircraft from conventional fixed-wing airplanes.

Aerodynamic-Parameter Identification and Attitude Control of Quad-Rotor Model with CIFER and Adaptive LADRC

“…Owing to the high degree of symmetry of the quad-rotor structure, the differences in the aerodynamic parameters and other aspects of the performance among the motors are very small, and the motors are considered to be approximately equal. The roll channel is taken as an example to illustrate the identification process of CIFER on a 3-DOF semi-physical simulation platform [31,32].…”

Implementasi dan Uji Kinerja Kontrol PID untuk kestabilan Pesawat Tanpa Awak Tailsitter pada Keadaan Mengambang

“…Efek rotasi dan gangguan luar ini harus diminimalkan oleh suatu sistem kendali, teknik kendali yang akan digunakan adalah kontrol PID (Proportional Integral Derivative) [8], [9] . Prinsip kerja kontrol PID adalah menggunakan error yang didapat sebagai aksi yang digunakan untuk memperbaiki error yang terbaca [10], [11].…”

Full Attitude Control of an Efficient Quadrotor Tail-sitter VTOL UAV with Flexible Modes

“…First, for the Pixhawk 4 flight stack, a second-order Butterworth low-pass filter P lf at 69 Hz has been used to isolate the disturbance coming from rotors whose frequency is between 75 Hz and 90 Hz. This low pass filter is lumped into the aircraft system when identifying the model and therefore is used as a component in the fitted model (i.e., (13)). Then, we use a second order transfer function P Dy (14) which consists of an integrator, two zeros, and one pole to approximate the system main dynamics.…”

“…The control force and torque are only produced by the four rotors, which means a more concise and unified controller can be designed. For the previous configuration, the different mixers are used for the hover, transition, and forward flight [6], [13]. In this paper, the unified attitude and altitude controllers are proposed for all the conditions with a large-range angle of attack and velocity.…”