Hybrid Field Oriented and Direct Torque Control for Sensorless BLDC Motors Used in Aerial Drones

In this study, a sensorless hybrid control scheme for brushless direct current (BLDC) motors for use in multirotor aerial vehicles is introduced. In such applications, the control scheme must satisfy high-performance demands for a wide range of rotor speeds and must be robust to motor parameter uncertainties and measurement noise. The proposed controller combines field-oriented control (FOC) and direct torque control (DTC) techniques to take benefit of the advantages offered by each of these techniques individually. Simulation results demonstrate the effectiveness of the proposed control scheme over a wide range of rotor speeds as well as good robustness against parameter uncertainties within -5to + 10% for inductance and -5to + 5% for resistance parameters. The proposed hybrid controller is robust also against noise in voltage and current measurements. In order to verify the results from simulation, the proposed hybrid controller is implemented in hardware using the TI C2000 Piccolo Launchpad and TI BOOSTXL-DRV8305EVM BoosterPack. Testing is done with a Bull Running motor typically used in aerial drones. Testing experiments demonstrate that the hybrid controller reduces the rotor speed ripple when compared to DTC while operating in steady-state mode and decreases the response time to desired speed changes when compared to FOC

Design, Modeling, and Control of a Flying-Insect-Inspired Quadrotor with Rotatable Arms

Aerial manipulation and delivery using quadrotors are becoming more and more popular in recent years. However, the displacement of the center of gravity (CoG) is a common issue experienced by these applications due to various eccentric payloads carried. Conventional quadrotors with eccentric payloads are usually stabilized by robust control strategies through adjusting rotation speeds of BLDC motors, which has negative effects on stability and energy efficiency of quadrotors. In this thesis, a flying-insect-inspired quadrotor with rotatable arms is proposed. With four rotatable arms, the proposed quadrotor can automatically estimate the displacement of the CoG and drive the four arms to their optimal positions during flight. In this way, the proposed quadrotor can move its symmetric center to the CoG of the quadrotor with the eccentric payload to increase its stability and energy efficiency. The design, dynamics modeling, and control strategy of the proposed quadrotor are presented in this thesis. Both calculation and experiment results show that the proposed quadrotor with rotatable arms has better flight performance of stability and energy efficiency than the conventional quadrotor with fixed arms

Stability region of a simplified multirotor motor–rotor model with time delay and fractional-order PD controller

The main aim of this paper is to present stability region analysis for a closed-loop system with the second-order model with a time delay and continuous-time fractional-order proportionalderivative (PD) controller. The model of the plant used in the paper approximates the dynamics of a simplified motor–rotor model of multirotor’s propulsion system. The controller tuning method is based on Hermite–Biehler and Pontryagin theorems. The tracking performance is also analysed in the paper by observing the integral of absolute error and integral of squared error indices. The presented results are expected to be useful in future when comparing simulation with experimental results

Simulated Annealing-Based Optimal Proportional-Integral-Derivative (PID) Controller Design: A Case Study on Nonlinear Quadcopter Dynamics

In this thesis, the history and evolution of rotor aircraft with simulated annealing-based PID application were reviewed and quadcopter dynamics are presented. The dynamics of a quadcopter were then modeled, analyzed, and linearized. A cascaded loop architecture with PID controllers was used to stabilize the plant dynamics, which was improved upon through the application of simulated annealing (SA). A Simulink model was developed to test the controllers and verify the functionality of the proposed control system design. In addition, the data that the Simulink model provided were compared with flight data to present the validity of derived dynamics as a proper mathematical model representing the true dynamics of the quadcopter system. Then, the SA-based global optimization procedure was applied to obtain optimized PID parameters. It was observed that the tuned gains through the SA algorithm produced a better performing PID controller than the original manually tuned one. Next, we investigated the uncertain dynamics of the quadcopter setup. After adding uncertainty to the gyroscopic effects associated with pitch-and-roll rate dynamics, the controllers were shown to be robust against the added uncertainty. A discussion follows to summarize SA-based algorithm PID controller design and performance outcomes. Lastly, future work on SA application on multi-input-multi-output (MIMO) systems is briefly discussed

Backpropagating constraints-based trajectory tracking control of a quadrotor with constrained actuator dynamics and complex unknowns

In this paper, a backpropagating constraints-based trajectory tracking control (BCTTC) scheme is addressed for trajectory tracking of a quadrotor with complex unknowns and cascade constraints arising from constrained actuator dynamics, including saturations and dead zones. The entire quadrotor system including actuator dynamics is decomposed into five cascade subsystems connected by intermediate saturated nonlinearities. By virtue of the cascade structure, backpropagating constraints (BCs) on intermediate signals are derived from constrained actuator dynamics suffering from nonreversible rotations and nonnegative squares of rotors, and decouple subsystems with saturated connections. Combining with sliding-mode errors, BC-based virtual controls are individually designed by addressing underactuation and cascade constraints. In order to remove smoothness requirements on intermediate controls, first-order filters are employed, and thereby contributing to backstepping-like subcontrollers synthesizing in a recursive manner. Moreover, universal adaptive compensators are exclusively devised to dominate intermediate tracking residuals and complex unknowns. Eventually, the closed-loop BCTTC system stability can be ensured by the Lyapunov synthesis, and trajectory tracking errors can be made arbitrarily small. Simulation studies demonstrate the effectiveness and superiority of the proposed BCTTC scheme for a quadrotor with complex constrains and unknowns

Design and Control of UAV Systems: A Tri-Rotor UAV Case Study

The field of UAV systems is an active research area with potential for development and enhancement in various perspectives. This thesis investigates different issues related to the design, operation and control of UAV systems with a focus on the application side of each proposed solution where the implementation side and applicability of the proposed solutions are always considered with high priority. The thesis discusses unmodeled actuator dynamics and their effect on UAV systems when using feedback linearisation to linearize nonlinear models of UAVs. The analysis shows potential risk when implementing feedback linearisation and neglecting actuator dynamics even for first order actuator system. A solution algorithm of two stage feedback linearisation is proposed to handle actuator dynamics and linearize the main dynamics of the system. In the field of design and operation of UAVs, this thesis proposes a systematic design procedure for electric propulsion systems that are widely used in UAVs. The design procedure guides the designer step by step to achieve minimum propulsion system weight or maximum flight time or a trade off between the two factors from the supplied solution sets. On the navigation side, the thesis proposes a new indoor navigation system that is easy to implement and less costly compared with other indoor navigation systems. The proposed system can be classified under computer-vision based navigation systems, however, it needs less information and less computational capacity. The thesis also contributes to the structure design of UAV systems by producing a novel tri-rotor UAV platform. The proposed UAV is novel in structure and design and has a centralized control system that stabilizes and tracks both rotational and transitional motion of the vehicle simultaneously

Rotational speed control of multirotor UAV's propulsion unit based on fractional-order PI controller

In this paper the synthesis of a rotational speed closed-loop control system based on a fractional-order proportional-integral (FOPI) controller is presented. In particular, it is proposed the use of the SCoMR-FOPI procedure as the controller tuning method for an unmanned aerial vehicle’s propulsion unit. In this framework, both the Hermite-Biehler and Pontryagin theorems are used to predefine a stability region for the controller. Several simulations were conducted in order to try to answer the questions – is the FOPI controller good enough to be an alternative to more complex FOPID controllers? In what circumstances can it be advantageous over the ubiquitous PID? How robust this fractional-order controller is regarding the parametric uncertainty of considered propulsion unit model?info:eu-repo/semantics/publishedVersio

Single chip solution for stabilization control & monocular visual servoing of small-scale quadrotor helicopter

This thesis documents the research undertaken to develop a high-performing design of a small-scale quadrotor (four-rotor) helicopter capable of delivering the speed and robustness required for agile motion while also featuring an autonomous visual servoing capability within the size, weight, and power (SWaP) constraint package. The state of the art research was reviewed, and the areas in the existing design methodologies that can potentially be improved were identified, which included development of a comprehensive dynamics model of quadrotor, design and construction of a performance optimized prototype vehicle, high-performance actuator design, design of a robust attitude stabilization controller, and a single chip solution for autonomous vision based position control. The gaps in the current art of designing each component were addressed individually. The outcomes of the corresponding development activities include a high-fidelity dynamics and control model of the vehicle. The model was developed using multi-body bond graph modeling approach to incorporate the dynamic interactions between the frame body and propulsion system. Using an algorithmic size, payload capacity, and flight endurance optimization approach, a quadrotor prototype was designed and constructed. In order to conform to the optimized geometric and performance parameters, the frame of the prototype was constructed using printed circuit board (PCB) technology and processing power was integrated using a single chip field programmable gate array (FPGA) technology. Furthermore, to actuate the quadrotor at a high update rate while also improving the power efficiency of the actuation system, a ground up FPGA based brushless direct current (BLDC) motor driver was designed using a low-loss commutation scheme and hall effect sensors. A proportional-integral-derivative (PID) technology based closed loop motor speed controller was also implemented in the same FPGA hardware for precise speed control of the motors. In addition, a novel control law was formulated for robust attitude stabilization by adopting a cascaded architecture of active disturbance rejection control (ADRC) technology and PID control technology. Using the same single FPGA chip to drive an on-board downward looking camera, a monocular visual servoing solution was developed to integrate an autonomous position control feature with the quadrotor. Accordingly, a numerically simple relative position estimation technique was implemented in FPGA hardware that relies on a passive landmark/target for 3-D position estimation. The functionality and effectiveness of the synthesized design were evaluated by performance benchmarking experiments conducted on each individual component as well as on the complete system constructed from these components. It was observed that the proposed small-scale quadrotor, even though just 43 cm in diameter, can lift 434 gm of payload while operating for 18 min. Among the ground up designed components, the FPGA based motor driver demonstrated a maximum of 4% improvement in the power consumption and at the same time can handle a command update at a rate of 16 kHz. The cascaded attitude stabilization controller can asymptotically stabilize the vehicle within 426 ms of the command update. Robust control performance under stochastic wind gusts is also observed from the stabilization controller. Finally, the single chip FPGA based monocular visual servoing solution can estimate pose information at the camera rate of 37 fps and accordingly the quadrotor can autonomously climb/descend and/or hover over a passive target

RANCANG SISTEM PENGENDALIAN SELF BALANCING PLANT MENGGUNAKAN DUAL MOTOR PROPELLER BERBASIS ADAPTIVE NEURO FUZZY INFERENCE SYSTEM

Abstrak Pesawat tanpa awak atau UAV (Unmanned Aerial Vehicle) telah berkembang dengan pesat di berbagai bidang. Sistem tak berawak adalah paltform otonom yang dapat dengan mudah diprogram untuk menjalankan misi dengan atau tanpa campur tangan pilot. Salah satu jenis UAV berdasarkan penggeraknya yang digunakan dalam penelitian ini adalah UAV multirotor di mana sistem penggerak terdiri dari dua buah motor beserta propeller yang biasa disebut dengan dual motors atau twin rotors. Sehubungan dengan ketahanan mekanik dan bahan bakar, kemampuan melayang, dan kegunaannya yang dapat digunakan di dalam ruangan maka UAV jenis ini memiliki peranan yang cukup penting dalam penelitian stabilisasi UAV apabila terdapat beban berlebih, untuk menghinadari kecelakaan di udara maupun untuk mencapai tingkat presisi dan akurasi posisi UAV dengan tepat. Pengontrolan stabilisasi dual motor diterapkan dalam kajian penelitian ini dengan mengontrol kecepatan brushless DC motor agar dapat menyetimbangkan posisi UAV itu sendiri. Metode yang diterapkan adalah metode simulasi plant dengan data sekunder sebagai acuan pengaturan parameter komponen menggunakan aplikasi Matlab 2018a. Pengujian plant secara simulasi menghasilkan nilai ANFIS yang cukup baik dengan nilai waktu naik (tr) = 4.145 s, waktu tunak (ts) = 7.5439 s, simpangan maksimum (Mp) = 0.489 %, dan Ess = 0.000741 %. Kata Kunci: ANFIS, dual motor, self balancing