Black-Box Modelling For Brushless Dc Motor And Control Strategy For Quadcopter Applications

The uses of brushless DC motor in quad copter application gives rise to a new demand. Quad copter drone usually uses brushless DC motor due to high performance, high efficiency and small volume. The function of brushless DC motor in quad copter is for positioning and velocity of the drone itself. Surely brushless DC motor gives more efficiency and effectiveness compared to brush motor. In order to analyse the responses of the brushless DC motor and control strategy for quad copter applications, black box modelling is invent. Black box or known as experimental modelling is a method for the development of process database of the models. Since physical simulation cost so much times, black box modelling is a common way to gain the overall behaviour process input and output. Typically, the built model used for estimation of potential process values or in application for process management. Important aspects in black box modelling which is system analysis, data conditioning, key variable analysis, model structure design, model identification and model evaluation. Software that been used is MATLAB and Simulink. The MATLAB and Simulink software used to demonstrate and measure the effective performance of the concept. The software helps in designing and identification of the system of the quad copter. Usually, the performances of different linearity of the models give different results of the models. Surely, linear transfer function models gives the best result for the simulation

Analysis and simulation of the high-speed torque performance of brushless D.C. motor drives

PhD ThesisThe work presented in this thesis is concerned with the analysis, modelling, simulation and control of a surface mounted permanent magnet motor supply by a voltage controlled Pulse-Width Modulation (PWM) inverter. In Chapter 1 an overall description of the design and construction of individual components of the brushless dc drive system is presented along with a review of the general concept of the drive system. This type of machine is compared with other types of machine and the potential advantages of this new concept, both technical and economic, outlined. In Chapter 2 the operation and the control aspects of the brushless dc motor are described, with particular emphasis placed on the basic requirements for the operation, torque production, performance characteristic and control. The high-speed torque control methods are also described and their merits are reviewed. In addition the effects of different parameters of machine design on the torque-speed characteristics are discussed. Chapter 3 elaborates on the analysis and simulation work by presenting a comprehensive analysis which aims to show that direct three-phase representation can be used as an effective tool for performance assessement of brushless dc drive systems operating over a wide speed range. In Chapter 4 the performance of the brushless dc motor supplied by a PWM inverter with a view to improving the high-speed torque performance is investigated. Simulation and analysis of the brushless dc motor is presented in which the actual parameters of the experimental machine are used. The aim of the analysis is to simulate a brushless d. c. drive system operating in closed-loop control modes, which use high speed torque control techniques in conjunction with a PWM control technique. A detailed analytical model which makes possible the use of machine theory for representing the performance of the brushless dc motor is presented in Chapter 5. The method utilizes the phasor diagram, where machine performance in terms of the main control variables such as voltage and phase advance angle is demonstrated. Chapter 5 also presents an analytical expression for the phase-advance angle which yields maximum torque at a given motor speed. An analytical study concerning the optimum phase advance is developed in Chapter 6. In this work two analytical approaches to the problem of obtaining an optimum phase advance angle are presented. Chapter 6 presents a detailed analysis of the shape of the current and back-emf waveforms in a trapezoidal brushless dc motor drive and their effects on the torque/speed performance. Chapter 7 presents the implementation of a microprocessor based system, which can set the phase advance angle to its optimum value at any motor speed. This implementation is done in real time on the protortype drive using a TMS320C30 digital signal processor. Features of the method proposed in this thesis include the estimation algorithms for predicting the time advance. Experimental results on a drive system demonstrate the satisfactory performance of both the hardware and software of the control scheme

A holistic integrated dynamic design and modelling approach applied to the development of ultraprecision micro-milling machines

Ultraprecision machines with small footprints or micro-machines are highly desirable for micro-manufacturing high-precision micro-mechanical components. However, the development of the machines is still at the nascent stage by working on an individual machine basis and hence lacks generic scientific approach and design guidelines. Using computer models to predict the dynamic performance of ultraprecision machine tools can help manufacturers substantially reduce the lead time and cost of developing new machines. Furthermore, the machine dynamic performance depends not only upon the mechanical structure and components but also the control system and electronic drives. This paper proposed a holistic integrated dynamic design and modelling approach, which supports analysis and optimization of the overall machine dynamic performance at the early design stage. Based on the proposed approach the modelling and simulation process on a novel 5-axis bench-top ultraprecision micro-milling machine tool – UltraMill – is presented. The modelling and simulation cover the dynamics of the machine structure, moving components, control system and the machining process, and are used to predict the overall machine performance of two typical configurations. Preliminary machining trials have been carried out and provided the evidence of the approach being helpful to assure the machine performing right at the first setup

Quantifying the commutation error of a BLDC machine using sensorless load angle estimation

BLDC motors are often used for high speed applications, for example in pumps, ventilators and refrigerators. For commutation discrete position information is necessary. This feedback is often provided by Hall sensors instead of more expensive encoders. However, even small misalignment of the Hall sensors in low cost BLDC motors can lead to unwanted torque ripples or reduced performance of BLDC motors. This misplacement leads not only to noise and vibrations caused by the torque ripples but also to lower efficiency. In this paper, a self-sensing technique to assess the misalignment is introduced. The objective is to obtain knowledge of the quality of the commutation by quantifying the misalignment. The method used in this paper is based on the fundamental components of voltage and current measurements and only needs the available current and voltage signals and electrical parameters such as resistance and inductance to estimate the misalignment

Automation of finite element aided design of induction motors using multi-slice 2D models

Purpose – To develop a practical design tool employing a general purpose electromagnetic finite element (FE) software package to perform automated simulation and performance analysis of induction motors in a design and optimisation process. Design/methodology/approach – Recent publications identified a suitable approach in applying 2D finite-element analysis to 3D problems. This, together with other similar work carried out on brushless DC motors, set out a framework for program development. Performance of the program was validated against practical test data. Findings – Finite-element analysis-based design tools can be realistically employed within a design office environment and are capable of providing solutions within acceptable time scales. Such tools no longer require user expertise in the underlying FE modelling method. The multiple slice technique was employed to model skew in three-phase induction motors and it was established that a four-slice model provides a good balance between accuracy and speed of computation. Research limitations/implications – Program development was based on one commercial FE software package and comparison with practical test data was not exhaustive. However, the approach outlined confirms the practical application. Future work could consider alternative approaches to optimisation. Practical implications – Computing hardware and commercially available 2D FE software have developed sufficiently to enable multi-slice techniques and optimisation to be employed in the analysis and design of machines. Originality/value – This paper provides a practical illustration of how commercial electromagnetic software can be employed as a design tool, demonstrating to industry that such tools no longer need to be bespoke and can realistically be used within a design office

Position estimation and performance prediction for permanent-magnet motor drives

PhD ThesisThis thesis presents a theoretical and experimental development of a novel position estimator, a simulation model, and an analytical solution for brushless PM motor drive. The operation of the drive, the position estimation model of the test motor, development of hardware, and basic operation of inverter are discussed. Starting with the well-known continuous-time model of brushless PM motor, a sampled-data model is developed that is suitable for th6, application of real-time position estimator. An analytical methodo f calculating the steady-stateb ehaviouro f the brushlessP M motor for 1200in verter operation is presentedT. he analysisa ssumesth at the machinea ir gap is free of saliency effects, and has sinusoidal back EMF. The analytical solution is derived for 60" electrical of the whole period. By experimental results, it is shown that the method of analysis is adequate to predict Ihe motor's performance for typical operating points including phase advance and phase delay operation. C) I A computer simulation model for prediction of the performance of brushless PM moto rs is presented. The model is formulated entirely in the natural abc frame of reference, which allows direct comparison of the simulation and corresponding experimental results. The equations and diagrams are put into a convenient form for the simulation and future developments and library modules. The simulation model and corresponding experimental data of the brushless PM motor drive is given. The thesis describes a modem solution to real-time rotor position estimation, which has been subject to intense research activity for the last 15 years. The implemented new algorithm for shaft position sensorless operation of PM motors is based on the flux linkage and line current estimation. The position estimation algorithm has also been verified by both off-line and on-line experiments (accomplished by a DSP, TMS320C30), and a wide range of steady-statea nd transient results have been 0gi0v en including starting from rest. The position estimation method effectively moves the position measurement point in the drive from the mechanical side to the motor's terminals. As well as eliminating the mechanical shaft position sensor, the investigated method can be used for high performance torque control of brushless PM motors. The thesis demonstrates that, in contrast to many other "sensorless" schemes, the new position estimation method is able to work effectively over the full operating range of the drive, and is applicable to a wide range of motor/converter types. Since the hardware is straightforward, only the new position estimation algorithm differentiates a system. Therefore, if a DSP control system is already implemented in the drive, the position estimator can be implemented at low cost.Istanbul Technical University and Higher Education Counci

Performance optimization in switched reluctance motor drives

In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. A prototype machine has been developed as very attractive design for a steering electric motor, both from a cost and size perspective. A fourphase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design

On Advanced Mobility Concepts for Intelligent Planetary Surface Exploration

Surface exploration by wheeled rovers on Earth's Moon (the two Lunokhods) and Mars (Nasa's Sojourner and the two MERs) have been followed since many years already very suc-cessfully, specifically concerning operations over long time. However, despite of this success, the explored surface area was very small, having in mind a total driving distance of about 8 km (Spirit) and 21 km (Opportunity) over 6 years of operation. Moreover, ESA will send its ExoMars rover in 2018 to Mars, and NASA its MSL rover probably this year. However, all these rovers are lacking sufficient on-board intelligence in order to overcome longer dis-tances, driving much faster and deciding autonomously on path planning for the best trajec-tory to follow. In order to increase the scientific output of a rover mission it seems very nec-essary to explore much larger surface areas reliably in much less time. This is the main driver for a robotics institute to combine mechatronics functionalities to develop an intelligent mo-bile wheeled rover with four or six wheels, and having specific kinematics and locomotion suspension depending on the operational terrain of the rover to operate. DLR's Robotics and Mechatronics Center has a long tradition in developing advanced components in the field of light-weight motion actuation, intelligent and soft manipulation and skilled hands and tools, perception and cognition, and in increasing the autonomy of any kind of mechatronic systems. The whole design is supported and is based upon detailed modeling, optimization, and simula-tion tasks. We have developed efficient software tools to simulate the rover driveability per-formance on various terrain characteristics such as soft sandy and hard rocky terrains as well as on inclined planes, where wheel and grouser geometry plays a dominant role. Moreover, rover optimization is performed to support the best engineering intuitions, that will optimize structural and geometric parameters, compare various kinematics suspension concepts, and make use of realistic cost functions like mass and consumed energy minimization, static sta-bility, and more. For self-localization and safe navigation through unknown terrain we make use of fast 3D stereo algorithms that were successfully used e.g. in unmanned air vehicle ap-plications and on terrestrial mobile systems. The advanced rover design approach is applica-ble for lunar as well as Martian surface exploration purposes. A first mobility concept ap-proach for a lunar vehicle will be presented