Reinforcement-learning control framework and sensing paradigm for flapping-wing micro aerial vehicles

Insects are fascinating for their maneuverability and complex aerobatics. Flapping-wing micro aerial vehicles are inspired from insect flight and aim to achieve high maneuverability at low speeds as well as hovering. Such a vehicle would have unique applications in social and economic sectors as well as in the military. This work, introduces a learning approach to flight control for flapping-wing micro aerial vehicles. A reinforcement-learning control framework has been proposed as a suitable biomimetic candidate for control of micro aerial vehicles. This work also discusses a matching sensing paradigm as a byproduct of the control approach. The control framework is then implemented using the Q-learning algorithm for the case study of lift generation for microflight. The results from a computer simulation using a quasi-steady aerodynamic model, and from an experimental investigation on a dynamically scaled model, confirm the applicability of the proposed framework. Moreover, the results of the learning scheme are shown to be comparable to a biological fruit fly, Drosophila melanogaster, in terms of the mean lift-force coefficient and the mean aerodynamic efficiency.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

Input current ripples cancellation in bidirectional switched-inductor quasi-Z-source inverter using coupled inductors

This paper proposes a new topology of switched-inductor quasi-Z-source impedance networks which has a high boost capability and continuous input current with no ripples. The coupling inductor technique is utilized to cancel the ripples of the input current. In this topology, no additional components such as input filter are required to protect the source. In addition, the lifetime of the storage elements would be increased. It is a bidirectional topology which is able to exchange energy between AC and DC energy storages in both directions and completely avoid the undesirable operation modes. Simulation results have validated the proposed strategy and have been in accordance to mathematical results

Direct torque control of in-wheel BLDC motor used in electric vehicle

Zero running emission, sustainability and efficiency of Electric Vehicle (EV) make it appropriate option for future transportation. In-wheel propulsion system of electric vehicles has been one of the main research concentrations in past decades. Brushless DC (BLDC) motor is the most suitable in-wheel motor because of its high efficiency, torque/speed characteristics, high power to size ratio, high operating life and noiseless operation. In this chapter direct torque control (DTC) switching technique with digital pulse width modulation (PWM) speed controller of BLDC motor for drive train system of EV has been reported. Effectiveness of the proposed BLDC motor drive is investigated through simulation and experiment. Obtained results show effective control of torque and remarkable reduction of torque ripple amplitude compare to conventional reported switching techniques. Improvements of in-wheel motor's torque controllability result to more efficient and safer electric vehicles

Comparison of dynamic responses of dual and single rotor wind turbines under transient conditions

Recently a new technology of wind turbines has been introduced which is going to have a remarkable share in the market in the close future. This wind turbine has two set of blades. So it is more efficient for collecting energy from wind in comparison to a single rotor wind turbine. This paper investigates the dynamic behaviour of the dual and single rotor wind turbines under unbalance transient conditions. To reach to this stage the models of mechanical and electrical components which exist in PSCAD/MTDC library have been used and combined together according to the configuration of the single and dual rotor systems. Both wind turbines are actuated and monitored from three aspects. Firstly, a step change in wind speed is applied which leads to a change in mechanical torque. Secondly, voltage sag is considered at the generator terminal which causes electromagnetic torque shock. Third, the amount of energies which is released by the mechanical systems after network frequency drop, are compared with each other to evaluate which one can support the frequency better. In all calculations the stream tube effect has been entered to the simulations. Different variables of wind turbines are evaluated and the operations of the rotors are compared

A Comparative Study on PFC Bridgeless Flyback and SEPIC AC-DC Rectifiers Operating in DCM and BCM

This paper presents a comparative study on the power factor corrector bridgeless SEPIC and Flyback ac-dc rectifier. First, a new SEPIC-based topology is proposed based on the existing Flyback topologies to remove the need of the input filter due to the existence of the input inductor in the SEPIC circuit. Then, both converters are analyzed and compared when operating in DCM and BCM, to evaluate the benefits of operating in BCM such as lower current stress on the switches and output diodes and hence lower conductive losses

Power reduction for an active suspension system in a quarter car model using MPC

Active suspension uses a powered actuator to provide real-time control of a suspension system to achieve better ride, comfort, and safety for passengers in a vehicle. This study concerns with the design of control schemes for an active suspension system in a quarter car model. In this paper, a quarter car model is presented, and ISO-based road profiles are used as perturbation for the system. Two control strategies, LQR and MPC with reference tracking have been investigated. Quadratic cost function for both the control schemes is optimized for the state and input variables. Simulation is carried out using MATLAB-SIMULINK and a comparison is presented for the ride index and actuator power. Simulations show considerable improvements in the suspension performance and power demand using MPC in comparison with LQR on two road classes. The performance improvements using MPC provides substantial evidence that indicates a reduction in the power requirements, actuator dimension and weight

Electric Vehicle with Multi-Speed Transmission: A Review on Performances and Complexities

Electric vehicles (EVs) with multi-speed transmission offer improved performances compared to those with single speed transmission system in terms of top speed, fast acceleration, or gradeability along with driving range. In this study, relevant literature is extensively analyzed to explore the performances and associated complexities with multi-speed automatic manual/mechanical transmission (AMT) system in EVs. In EV powertrain, the only torque generator component is electric motor, which is not equally efficient throughout wider speed range. To the other end, vehicles need to run at different speeds in diverse driving conditions. The study shows that multi-speed transmission system enables efficient operation of electric motor by choosing an appropriate gear at different driving torque-speed demands and thus contributes to achieve desired vehicle performances at minimum energy consumption. To demonstrate the differences, both dynamic and economic performances with multi-gear system and single speed system are compared, and the results of various techniques are presented in the form of tables and bar charts. A quantitative analysis is also conducted to show the performance improvement achievable by employing multi-speed transmission concept in EVs. Apart from additional mass, gear ratio selection and torque interruption during gear shifting are major obstacles to improve drivetrain efficiency and riding comfort in EVs with multi-speed transmission system. For optimal gear ratio in transmission system, genetic algorithm (GA) is found to be implemented in most articles. It is also observed that variable shift schedule needs to be considered during the optimization process to get the paramount gear ratios. Tables and bar charts are used to show the results of recent relevant works to these issues. In this article, the readers would gain a comprehensive knowledge on how multi-speed transmission technology can outperform the single speed system within EV platform and what the inherent challenges are

A Scheme-Based Review of MPPT Techniques With Respect to Input Variables Including Solar Irradiance and PV Arrays’ Temperature

Maximum power point tracking (MPPT) techniques have been vastly researched and developed in order to obtain the maximum terminal power of photovoltaic (PV) arrays in the solar renewable energy system. The aim of this paper is to present a new principal scheme-based review of the categorised MPPT methods (conventional, novel, and hybrid) with respect to the deployment of their input variables (solar irradiance, PV arrays' temperature, and PV arrays' terminal voltage and current), where MPPT methods are categorised to six different schemes. For each scheme, previous MPPT studies are extracted from literature and analysed. Then the critical benefits and limitations of the six presented MPPT schemes are compared and discussed. It is concluded that those MPPT schemes deploying the measured external variables would be able to track the global maximum power point with high reliability; however, their implementation cost and applicability remains as a challenge due to increasing the sensor deployment cost and complexity. The conclusion of this paper will help new researchers to deliberately select an appropriate MPPT scheme based on their projects' objectives and limitations, prior to selecting an optimisation algorithm for MPPT