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Coaxial-rotor configuration with the compact structure and vertical take-off ability make itself a good configuration to execute highly difficult task. In this paper, the structural design of coaxial-rotor system is introduced, and we discuss the control principle behind coaxial configuration. Then, the dynamic modeling is presented based on the combination of considering two rotors as dynamics model...
High speed generation derives its motivation from a variety of applications such as concentrated solar power (CSP) generation, hybrid automotive power generation and aerospace. Research is actively been pursued in the field of power generation using solar heat, where novel thermodynamic cycles like supercritical carbon dioxide (sCO2) Brayton and Organic Rankine Cycles are considered as superior options...
In contrast to the conventional underactuated quadrotor, an over-actuated tilt-rotor quadcopter equipped with four tilting rotors can fly the arbitrary position trajectory while maintaining the desired attitude. We study the translational and rotational dynamic model for the tilt-rotor quadcopter associated with disturbances and uncertainties. Using the tilting rotors, we design two sliding mode controls...
Usually, robot is designed by using only one locomotion mechanism, such as walking, hopping, and jumping. The reason, among others, are simplicity, saving energy, and focus on single task and mission. This paper deal with design and implementation of multimodal flying and crawling robot by using adaptive morphology. The aim of this development is to provide robot platform that could achieve multiple...
A simple piezoelectric motor driven by traveling guided waves on a circular cylindrical wedge is presented in this paper. The stator is constructed by attaching a metal circular cylindrical wedge to a piezoelectric tube. An inter-digital transducer painted on the outer surface of the piezoelectric tube is used to generate flexural waves propagating along the apex of the wedge. This piezomotor is driven...
This paper proposes a new modular arc-linear flux-switching permanent magnet motor (MAL-FSPM) used for directly driving objects rotate back and force within a limited angle. Due to double salient effect and end effect, cogging torque of MAL-FSPM is very high, especially for rotor end meeting stator end. A novel cogging torque reduction method is proposed. New structure of MAL-FSPM is established based...
Magnetic Lead Screw (MLS) can transfer slow linear motion into fast rotary motion offering much higher force density than that of traditional linear permanent magnet machines. It has been developed for ocean wave energy harvester and active damper for electrical vehicles. In this paper, a new type of MLS is proposed, where all the permanent magnets of the rotor and translator are magnetized along...
This paper analyzes the electromagnetic forces acting on the coaxial magnetic gear (CMG). The vibration and noise of CMG result from exciting forces acting on three parts namely low-speed rotor, high-speed rotor and modulating pieces (MPs), respectively. The forces acting on three parts of CMG are calculated. Also, these force frequencies are analyzed. The influence of forces on vibration and noise...
Non-skewed rotors can be used to eliminate the slot harmonic field, as well as, the noise and vibration can also be weakened effectively. However, it is difficult to determine the spatial distribution of the asymmetrical rotor bars and slot combinations, which can affect the loss and air-gap force significantly. Taking a 5.5kW, 4-pole induction motor as an example, this paper studies the influence...
The main purposes of this paper consist of two parts: Firstly, the geometric topology and operation principle of a novel outer-rotor-permanent-magnet flux-switching (ORPM-FS) machine is proposed and simply introduced. Secondly, based on 2D finite element method, phase back electromotive force (back-EMF) waveform of the ORPM-FS machines with different combinations of stator slots and rotor poles is...
In this paper, a multi-physics torque simulation of the nonmagnetic rotor submerged in ferrofluid is proposed. It is noted that there is no exerted magnetic force on the nonmagnetic materials. After calculation of magnetic force densities in ferrofluid, the pressures acting on the surface of rotor can be acquired from hydrostatics. Then torque is calculated from the surface pressures of rotor. A simple...
The hybrid excitation magnetic gear having the AC excitation and PM excitation is very useful in transmission system because it can operate with continuously variable gear ratio. But, the harmonic characteristics of flux density in hybrid excitation magnetic gear are different to those of PM excitation magnetic gear. Thus, these magnetic gears are compared in terms of the harmonic characteristics...
In this work a generalized dynamical model of the multi-rotor unmanned aerial vehicles (UAVs) is presented. The proposed model in six degrees of freedom (6DoF) is expressed as a function of the number of the system actuators and derived from Euler-Newton equations. A combined integral backstepping-PID controller is used to control the system performing a 3D trajectory tracking. The control approach...
Micro Aerial Vehicles (MAVs) are limited in their operation outdoors near obstacles by their ability to withstand wind gusts. Currently widespread position control methods such as Proportional Integral Derivative control do not perform well under the influence of gusts. Incremental Nonlinear Dynamic Inversion (INDI) is a sensor-based control technique that can control nonlinear systems subject to...
It is difficult to start permanent magnet synchronous motor (PMSM) when rotor initial position is unknown. To solve this problem, a PMSM starting scheme is proposed based on force analysis of the rotor located in different initial positions. Firstly, the equivalent model of PMSM's rotor is established and influences of rotor initial position on PMSM starting are analyzed. Then, the principle of PMSM...
During startup, a motor will draw anywhere from five to eight times the normal current required to run under full-load condition. An additional wearing effect of repeated starts or over an extended period of time is to cause expansion and contraction of material, and it will tend to become brittle and crack. In this paper, the electromagnetic force and structural static of the rotor in induction motor...
Flywheel energy storage system is a promising technology of high power storage and energy conversion for Hybrid Electric Vehicles (HEVs) and Electric Vehicles (EVs). As the safety issue is one of the top priorities of this technology, especially when the Active Magnetic Bearing (AMB) is utilized, a sensor-fault tolerant control method of AMB is proposed in this paper. In the method, specially designed...
Magnetic bearings have been used in flywheel energy storage systems for improving their performance due to the main advantage of contact-free operation.However, the gyroscopic coupling, parameter coupling and imbalance force affect the operating performance and stability of an magnetic suspended flywheel energy storage system with asymmetric rotor,therefore, a cross feedback based control method is...
Vibration control of active magnetic bearing rotor system during acceleration and deceleration operations is one of key problems in high speed flywheel energy storage system used in electric vehicles. In order to significantly suppress the vibration of the flywheel rotor, an adaptive filter based on Least Mean Square (LMS) algorithm is proposed. After introducing the principle of the LMS algorithm,...
With the development of general aviation, UAVs are increasingly used in all areas of our life. However, electric multi-rotor UAV can't achieve long-endurance, large load transport due to battery energy density. And hybrid power system is a perfect solution to this problem. This paper raised a parameter matching method of the UAV's hybrid power system related to the pulling force, required power and...
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