Coaxial Helicopter Research Articles

DESIGN ANALYSIS AND CONSTRUCTION OF ENERGY HARVESTING COAXIAL HELICOPTER

With the growing need for technology, the tendency for errors has increased many times, which often results in loss of human lives. Our main aim of this paper is to show the implementation of a coaxial rotor aerial vehicle that can be controlled by a radio frequency transmitter. The helicopter is capable of manoeuvring in an area where real helicopters cannot. The area could be a flooded region, a place hit by an earthquake, or a building on fire. The main aim is to transmit video of that place to a base station by the camera attached to the helicopter. Various factors required to make a safe and successful coaxial helicopter are discussed and extensive flight testing proves that this flying machine is better in efficiency and performance than a traditional single rotor aerial vehicle. The relation of flight parameters like torque, induced power, rpm, pitch, and total power are discussed. A piezoelectric sensor is used to determine the vibrations occurring in the body so that they can be minimised. A successful attempt to convert the vibrations into a charge by piezoelectric energy harvesters is made.

Identification and modeling of the three rotational movements of a miniature coaxial helicopter

This paper presents the identification of a miniature coaxial helicopter system. First, the helicopter flying principles are described and the hardware setup of the developed platform is presented. Further, linear models are developed for the movements of the helicopter using prediction error identification methods. The results in this case are accurate and can be used for performant controller design in some operating points. But in order to model the complete dynamics of the helicopter, nonlinear models are developed using recurrent dynamic neural networks. In this case the models obtained present a higher accuracy compared with the linear case and also with the results published until now. In the end, the advantages of nonlinear modeling based on neural networks is emphasized and some conclusions are drawn.

Stability and Control Analysis on a Small-Scale Coaxial Helicopter with Bell-Hiller Stabilizer Bar

In the paper, we present a linearized mathematical model of a small scale coaxial helicopter with Bell-Hiller stabilizer bar, which is extracted from numerical linearization of a non-linear mathematical model with small perturbation theory. Stability and control derivatives calculated by numerical method are compared and analyzed for stability and control analysis on coaxial helicopters equipped with different type stabilizer bar. The study indicates that the coaxial helicopter with stabilizer bar fixed on the upper rotors has better capability on stability and control.

1A2-G02 2重反転モータによる飛行体の自転制御によるフェールセーフ機能(飛行ロボット・メカトロニクス(2))

1A2-G02 2重反転モータによる飛行体の自転制御によるフェールセーフ機能(飛行ロボット・メカトロニクス(2))

Autonomous Miniature Flying Robots: COMING SOON!

he evolution of autonomous miniature flying robots (MFRs) is considerably intensified thanks to the recent growth of military and civil interest in unmanned aerial robotics that are able to perform different tasks such as surveillance and rescue. This article presents some of the research undertaken for the Automous Systems Lab (ASL) MFR project. It introduces a new design methodology adapted to rotorcraft MFRs and presents two different application examples: a mini quadrotor named OS4 and a compact coaxial rotor helicopter called CoaX. In addition to this, an original concept of hybrid active and passive control for CoaX is addressed. Finally, a simulation tool based on MATLAB and Simulink is described. This tool

Micro-Helicopter for Long-Distance Missions: Description and Attitude Stabilization

This paper presents the development of a micro coaxial helicopter (MCR UAV) whose main characteristic is that it should be carried by an air shuttle transporter and then released in a desired place far away from the launching site, to develop surveillance missions in hover flight. A real-time embedded system is built in order to validate the proposed aerodynamic prototype, and a classic control law based on a classical backstepping procedure for the dynamic system is implemented to test this vehicle in autonomous flight. Finally, simulation and practical results are presented for hover flight.

Experimental method for studying gust effects on micro rotorcraft

Micro rotorcraft have a great potential for both civilian and military applications, but for successful deployment, they must operate robustly in real-world environments including flight in winds. Due to their small size, common wind fields in and around buildings can represent a large percentage of the vehicle’s full flight envelope resulting in highly non-linear motion. An experimental method has been developed to evaluate the capabilities of micro rotorcraft in realistic wind conditions to aid in the design and evaluation of these vehicles. A synthetic wind generation system is used to create repeatable and controllable gust excitations, and a motion capture system is used for precise measurement of vehicle response. Performance metrics associated with the accuracy of position tracking and angular rate excursions are proposed to quantify vehicle capabilities at different excitation levels for design assessment and cross-platform comparison. To demonstrate the experimental method, test results are shown to evaluate the capabilities of a micro coaxial helicopter in realistic winds as a function of gust excitation level and vehicle size. For this example system, light wind gusts degrade hover hold accuracy by a factor of 3 compared to a situation with quiescent winds.

Bilateral Teleoperation of Multiple Mobile Agents: Coordinated Motion and Collision Avoidance

This paper presents theoretical and experimental results on bilateral teleoperation of multiple mobile slave agents coupled to a single master robot. We first design a passifying proportional-derivative (PD) controller to enforce motion tracking and formation control of master and slave vehicles under constant, bounded communication delays. Then, we incorporate avoidance functions to guarantee collision-free transit through obstructed spaces. The unified control framework is validated by experiments with two coaxial helicopters as slave agents and a haptic device as the master robot.

Model Predictive Attitude–Altitude Control for a Miniature Coaxial Helicopter

The aim of the work presented in this article is the design of a Model Predictive Control based on a Piecewise Linear modeling of the attitude and altitude motions of a Miniature Coaxial Helicopter that accounts for the physical and mechanical constraints of the system. Extended simulation studies present the efficiency of the proposed control scheme both in accurate rotational maneuvers, altitude tracking, and disturbance rejection.

Interactional aerodynamics and acoustics of a hingeless coaxial helicopter with an auxiliary propeller in forward flight

AbstractThe aerodynamics and acoustics of a generic coaxial helicopter with a stiff main rotor system and a tail-mounted propulsor are investigated using Brown’s Vorticity Transport Model. In particular, the model is used to capture the aerodynamic interactions that arise between the various components of the configuration. By comparing the aerodynamics of the full configuration of the helicopter to the aerodynamics of various combinations of its sub-components, the influence of these aerodynamic interactions on the behaviour of the system can be isolated. Many of the interactions follow a simple relationship between cause and effect. For instance, ingestion of the main rotor wake produces a direct effect on the unsteadiness in the thrust produced by the propulsor. The causal relationship for other interdependencies within the system is found to be more obscure. For instance, a dependence of the acoustic signature of the aircraft on the tailplane design originates in the changes in loading on the main rotor that arise from the requirement to trim the load on the tailplane that is induced by its interaction with the main rotor wake. The traditional approach to the analysis of interactional effects on the performance of the helicopter relies on characterising the system in terms of a network of possible interactions between the separate components of its configuration. This approach, although conceptually appealing, may obscure the closed-loop nature of some of the aerodynamic interactions within the helicopter system. It is suggested that modern numerical simulation techniques may be ready to supplant any overt reliance on this reductionist type approach and hence may help to forestall future repetition of the long history of unforeseen, interaction-induced dynamic problems that have arisen in various new helicopter designs.

1P1-F14 小型ヘリコプタの協調制御(飛行ロボット・メカトロニクス)

This paper presents cooperative control of two micro co-axial helicopters using vision-based control with occlusion handling. The helicopters do not have any sensors which measure their positions or postures. Eight stationary cameras are placed on the ground. The helicopter positions and postures are reconstructed by fusing the visual information. Experimental results demonstrate that automatic guidance control of micro-helicopters is performed.

小型2重反転回転翼機の前進飛行に関する研究

The toy model coaxial helicopter for entertainment has a characteristic that it goes left when the operation for forward motion is made with the controller. The reason for this characteristic was made clear as follows: The phase difference between cyclic pitch and flapping motion is varied with the forward velocity. For this helicopter, the azimuth angles for the cyclic pitch inputs to the lower rotor are determined for a hovering flight. Then, the tip path plane of the lower rotor is inclined to the left and forward, when the operation for forward motion is kept. And the fuselage moves to the left and forward. On the other hand, during the forward motion, the inclination of the tip path plane of the upper rotor is varied by the stabilizer bar, whose motion is mainly determined by the fuselage attitude. Then, there are both moments when the upper rotor suppresses the fuselage motion generated by the lower rotor and when it promotes the fuselage motion.

ステレオビジョンカメラを用いた同軸二重反転式ヘリコプタのモデリングと自律飛行制御

MAV (Micro Air Vehicle) will be very effective for gathering information in dangerous area or narrow space.In that case, autonomous control is essential. This paper is concerned with autonomous control of small co-axial helicopter: X.R.B. Horizontal acceleration is decided by force from lower rotor and upper rotor. Direction of the force is decided by angle of rotation surface of lower rotor, upper rotor and stabilizer. Therefore the model which physical meaning of parameter is clear can be constructed. Control system is constructed by LQI controller and Kalman filter using the model. Good control performance is achieved by experiment. 3D position of X.R.B is measured by using stereo vision camera and 3-axis attitude is measured by small attitude sensor.

Autonomous miniature flying robots: coming soon! - Research, Development, and Results

The exponential growth of the interest and investigations in UAVs is strongly pushing the emergence of autonomous MFRs. This article presented some developments in the ASL-MFR project. A new design methodology was introduced and applied to a quadrotor and a coaxial helicopter enhancing appreciably the robots characteristics by allowing 100% thrust margin and 30 min autonomy (respectively, 40% and 20 min for CoaX). An original concept of hybrid active and passive control is introduced for CoaX. A simulation software permitting rapid MFR reconfiguration and various testing conditions was shown. Finally, a simulation of an obstacle avoidance controller was presented. The numerous developments presented in this article reinforce our conviction in the emergence of autonomous MFRs.

2重反転回転翼に働くトルクの測定法について

Torque acting on a blade of a coaxial helicopter was estimated by measuring a lead-lag angle of the blade. The estimated torque was compared with the one measured by referring the characteristics of the motor. The comparison shows that the former method has the same accuracy as the latter method.

小型2重反転回転翼機のベル式スタビライザ・バーに関する研究

The motion of a stabilizer bar of the small coaxial helicopter was analyzed in the previous study. It has been made clear by the measurements on the motion of the stabilizer bar that the following two revisions are required in the analysis. (1) The motion of stabilizer bar is affected by the upper rotor. (2) Neither of the terms in the moment acting on the stabilizer bar at its hinge, kββ+kββ, can be ignored.

Analysis of Flapping Motion of Rotors of Small Coaxial Helicopter

We analyzed a small coaxial helicopter developed for entertainment in 2002. The upper and lower rotors are rigid rotors. The upper rotor is connected to a stabilizer bar. The cyclic pitch of the upper rotor is controlled by the stabilizer bar when the attitude of the helicopter is varied. The angle between the upper rotor and the stabilizer bar is 41°. The cyclic pitch of the lower rotor is controlled by servo motors and the inputs of the cyclic pitch from the servo motors are at the azimuth angles of 45°, 225° and 135°, 315°. This paper clarifies how the angle between the upper rotor and its stabilizer bar and the azimuth angles of the inputs of the cyclic pitch to the lower rotor are determined.

小型回転翼機の自律ホバリング飛行

During the 20th century, aircraft were only used for transportation. If aircraft can be made small and lightweight, however, they can become tools to assist in everyday life. We developed a small, lightweight co-axial helicopter with a rotor diameter of about 30cm. The mechanisms for varying cyclic pitch of the upper and lower rotors, which are used in the coaxial helicopter for entertainment, are adopted in our develop helicopter. Our developed helicopter is equipped with a flight control system for the attitude and position, which is composed of a micro computer and some sensors. And the helicopter can make autonomous hovering flight just measuring the height and the distances from the walls. The weight of the helicopter is no more than 200g and this helicopter is the lightest helicopter for an autonomous hovering flight among the helicopters where all control systems are onboard, as far as the authors know.

小型2重反転回転翼機の開発(S29 MAV,S29 小型飛翔体(MAV))

小型2重反転回転翼機の開発(S29 MAV,S29 小型飛翔体(MAV))

小型回転翼機の開発(レスキューシステム・レスキュー工学2)

小型回転翼機の開発(レスキューシステム・レスキュー工学2)