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In light of starting clutch control requirement in unmanned modified process of a helicopter, the control system with high-reliability circuit, excellent engagement quality and engine speed stability are researched. By analysing the disadvantantages of the original clutch control system, the improved design requirements are proposed. To achieve the requirements, half bridge chips are used in the control...
Autonomous mini helicopters are gaining popularity towards crowd monitoring, disaster management, intelligence, surveillance and reconnaissance. This is due to its advantage of vertical take-off and landing along with electro-optic payload carrying capability. The present work is a technology demonstrator project wherein a radio controlled mini helicopter is being converted into autonomous mini helicopter...
A Rotary-Wing Unmanned Aerial Vehicle (RWUAV) in the 500 kg class capable of fulfilling a number of missions, would represent a considerable capital outlay for any customer, as both the RWUAV as a platform and its payload comprising sophisticated sensors would be costly items. Therefore, in the event of an engine failure, a means should be provided to get the RWUAV safely back on the ground without...
In this study, a turboshaft engine performance is improved by design of high orders sliding mode controller. Engine dynamics are addressed with variation of gas generator speed as driven by the manufacturer. Proposed controller is designed to cover all parametric variations of the engine. Successful simulations have been performed to illustrate the effectiveness of the proposed solution technique.
In this paper a control structure based on feedback (Input-State) linearization has been applied to the elevation subsystem of a laboratory double rotor helicopter. This system is multivariable with 2 inputs and 4 outputs, highly nonlinear and strongly coupled. This article focuses on the elevation subsystem which, in turn, is underactuated with 1 input and 2 outputs. A switching control law between...
Flight test results of flight control performance of Smart UAV were described. Flight test in airplane mode was performed by internal pilot using automatic functions including auto take-off and landing, speed/altitude/heading hold as well as a point navigation and a preprogram mode. It reached to the designed maximum speed at operational altitude. The rotor speed in airplane mode was reduced to 82%...
A new procedure based on Hilbert-Huang Transform (HHT) was proposed to investigate the change of the exhaust gas temperature (EGT) of turbo shaft engine. Energy-frequency-time distribution of the signal can be established though empirical mode decomposition (EMD) and Hilbert transform, from which Hilbert energy spectrum was obtained. The energy spectrum was applied to indicate the energy distribution...
Flight test results of flying qualities for Helicopter mode of Smart UAV are described. Flight test items in helicopter mode include manual and automatic stick control as well as hold and navigation flight including automatic take off and landing. One of the main purposes of helicopter mode flight test is to evaluate the handling qualities in low speed region where nacelle angles are greater than...
A method is explored to realize automatic control of starting clutch. The clutch control requirements are determined based on the dynamics characteristics research of an unmanned helicopter clutch, and the analysis of clutch engagement process effect on transmission impact and belts life. The rotating speed of clutch driving pulley and driven pulley are selected as basic input parameters. The starting...
The aim of this work is to describe an intelligent system based on fuzzy logic that is developed to control a quadrotor. A quadrotor is a helicopter with four rotors, that make the vehicle more stable but more complex to model and to control. The quadrotor has been used as a testing platform in the last years for various universities and research centres. A quadrotor has six degrees of freedom, three...
In this paper, a full applicable procedure for design, optimization and manufacturing of an operational unmanned helicopter with deep and detailed research basis is presented. The proposed process deals with challenging aspects of manufacturing of the mentioned type of aircraft such as cost, weight, operation ability, reliability, mission justification, stability, performance, etc. To show the applicability...
Modeling of power system plays an important part in modeling of helicopter dynamics system. The precision of turbo-shaft engine model affects directly the fidelity of power system model in process of modeling and simulation on helicopter. Modeling techniques of turbo-shaft engine are studied first, secondly, engine control system model based on main rotor load feedback is proposed and an inner-outer...
The purpose of this communication is to investigate the usefulness of the differential flatness theory of a non linear system such as a four rotor aircraft to design an efficient fault detection scheme. The flight dynamics equations of a four rotor aircraft as well as the dynamics of the engines controlling the rotors are introduced. Then the differential flatness of the rotorcraft flight dynamics...
A general technique for generating specifications for integrated flight propulsion control is extended to include systems with significant two-way coupling between the flight and propulsion systems. These specifications define how the subsystems must perform within an integrated control system in order to assure that performance goals (specifically stability) are met when the subsystems are combined...
Despite the impact that the Stable Factorization (SF) approach has had on the academic community, its widespread acceptance and application by industry has been hampered by the natural lag in the development of design algorithms and their associated numerically reliable CAD implementations. Indeed, it is safe to say that computer-aided design support for the Stable Factorization methodology (and in...
In this paper we examine the design of scalar and multi-variable feedback control systems for the GE T700 turboshaft engine coupled to a helicopter rotor system. A series of linearized models are presented and analyzed. Robustness and performance specifications are posed in the frequency domain. The LQG/LTR methodology is used to obtain a sequence of three feedback designs. Even in the single-input...
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