Design of an embedded microcomputer based mini quadrotor UAV

This paper describes the design and realization of a mini quadrotor UAV (Unmanned Aerial Vehicle) that has been initiated in the Systems and Control Laboratory at the Computer and Automation Research institute of the Hungarian Academy of Science in collaboration with control departments of the Budapest University of Technology and Economics. The mini quadrotor UAV is intended to use in several areas such as camera-based air-surveillance, traffic control, environmental measurements, etc. The paper focuses upon the embedded microcomputer-based implementation of the mini UAV, describes the elements of the implementation, the tools realized for mathematical model building, as well as obtains a brief outline of the control design

Mitigating ground effect on mini quadcopters with model reference adaptive control

Mitigating ground effect becomes a big challenge for autonomous aerial vehicles when they are flying in close proximity to the ground. This paper aims to develop a precise model of ground effect on mini quadcopters, provide an advanced control algorithm to counter the model uncertainty and, as a result, improves the command tracking performance when the vehicle is in the ground effect region. The mathematical model of ground effect has been established through a series of experiments and validated by a flight test. The experiments show that the total thrust generated by rotors increases linearly as the vehicle gets closer to the ground, which is different from the commonly-used ground effect model for a single rotor vehicle. In addition, the model switches from a piecewise linear to a quadratic function when the rotor to rotor distance is increased. A control architecture that utilizes the model reference adaptive controller (MRAC) has also been designed, where MRAC is added to the altitude loop. The performance of the proposed control algorithm has been evaluated through a set of flight tests on a mini quadcopter platform and compared with a traditional proportional–integral–derivative (PID) controller. The results demonstrate that MRAC dramatically improves the tracking performance of altitude command and can reduce the rise time by 80 % under the ground effect

Experimental implementation controlled SPWM inverter based harmony search algorithm

An optimum PI controller using harmony search optimization algorithm (HS) is utilized in this research for the single-phase bipolar SPWM inverter. The aim of this algorithm is to avoid the conventional trial and error procedure which is usually applied in finding the PI coefficients in order to obtain the desired performance. Then, the control algorithm of the inverter prototype is experimentally implemented using the eZdsp F28355 board along with the bipolar sinusoidal pulse width modulation (SPWM) to control the output voltage drop under different load conditions. The proposed overall inverter design and the control algorithm are modelled using MATLAB environment (Simulink/m-file Code). The mean absolute error (MAE) formula is used as an objective function with the HS algorithm in finding the adaptive values of  and  parameters to minimize the error of the inverter output voltage. Based on the output results, the proposed voltage controller using HS algorithm based PI (HS-PI) showed that the inverter output performance is improved in terms of voltage amplitude, robustness, and convergence rate speed as compared to PSO algorithm based PI (PSO-PI). This is to say that the proposed controller provides a good dynamic responses in both cases; transient and steady-state. Finally, the experimental setup result of the inverter controller is verified to validate the simulation results

Kesan penggunaan prosedur pembelajaran kawalan kendiri (self-regulated learning) terhadap pencapaian akademik, kemahiran meta kognitif dan motivasi pelajar politeknik : kajian kes

Pembelajaran Kawalan Kendiri (PKK) merupakan satu strategi pembelajaran efektif yang membantu pelajar untuk kompeten dan mempunyai autonomi dalam diri. Namun, prosedur yang betul bagi mengaplikasikan PKK masih memerlukan penambahbaikan disebabkan oleh pelajar cepat bosan belajar subjek teori. Pelajar juga didapati mengamalkan surface learning, mudah hilang fokus dalam kelas dan tidak cekap dalam mengawal kemahiran meta kognitif. Oleh itu, tujuan kajian ini dilaksanakan adalah untuk membangunkan satu prosedur PKK khusus untuk pelajar politeknik yang mengambil subjek Prinsip Pengurusan dan diuji keberkesanannya terhadap pencapaian akademik, kemahiran meta kognitif dan motivasi pelajar. Terdapat dua (2) fasa telah digunakan dalam kajian ini. Fasa pertama (1) ialah pembangunan prosedur PKK menggunakan analisis dokumen dan model Kemp. Analisis frekuensi telah digunakan dalam fasa ini. Terdapat tiga (3) hasil dapatan kajian daripada fasa pembangunan iaitu Prosedur PKK, Aktiviti Pengajaran dan Rancangan Pengajaran Harian (RPH). Fasa kedua (2) ialah pelaksanaan prosedur PKK menggunakan reka bentuk kuasi eksperimen iaitu ujian pra-pasca bagi kumpulan-kumpulan tidak seimbang. 43 orang pelajar Politeknik Sultan Haji Ahmad Shah (POLISAS) telah dipilih sebagai kumpulan rawatan manakala 38 orang pelajar Politeknik Merlimau (PMM) sebagai kumpulan kawalan. Analisis deskriptif skor min dan analisis inferensi MANCOVA telah digunakan dalam kajian ini bagi menguji perbezaan antara kumpulan kajian. Berdasarkan hasil analisis MANCOVA yang telah dijalankan, didapati wujud perbezaan yang signifikan secara statistik antara kumpulan rawatan dan kawalan bagi pencapaian akademik [F (1, 76) = 24.786, p = .000], kemahiran meta kognitif [F (1, 76) = 14.864, p = .000] dan motivasi [F (1, 76) = 65.148, p = .000]. Kesimpulannya, prosedur PKK terbukti berkesan dan boleh dijadikan panduan kepada pensyarah dalam mengaplikasikan PKK dengan lebih efektif dan berkesan

Mini-quadrotor Attitude Control based on Hybrid Backstepping & Frenet-Serret Theory

This paper is about modeling and control of miniature quadrotors, with a special emphasis on attitude control. Mathematical models for simulation and nonlinear control approaches are introduced and subsequently applied to commercial aircraft: the DraganFlyer quadrotor, which has been hardware-modified in order to perform experimental autonomous flying. Hybrid Backstepping control and the Frenet-Serret theory is used for attitude stabilization, introducing a desired attitude angle acceleration function dependent on aircraft velocity. Finally, improvements on disturbance rejection and attitude tracking at moderate aircraft speeds are validated through various simulation scenarios (indoor navigation based on camera tracking), and flight experiments conducted on the DraganFlyer quadroto