摘要:

The integrated flight/propulsion control system development of the ‘STOL and Manoeuvre Technology Demonstrator’ was unique in several aspects. Thrust reversing and pitch vectoring were fully integrated into the flight control system so that they they were transparent to the pilot across the complete flight envelope. Various pilot-selectable modes were designed into the control system to allow in-flight comparison of different factors, such as flying qualities optimized for flight path control or for pitch tracking, and architectures featuring conventional or decoupled landing control laws. The control laws were designed and implemented using a combination of classical and multivariable techniques. The classical technique included a novel inverse process of designing directly to the equivalent system transfer function satisfying the flying qualities specification. The linear quadratic gaussian multivariable technique was used for the modes/axes with the most complex requirements. The rationale is presented for the choices of which design was implemented for flight. Many flying qualities requirements were subject to special interpretation or redefinition through this development. This paper documents the complete control system design development from customer specification through the successful flight test programme.

ISSN:0020-7179    

DOI:10.1080/00207179408923076

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The Institute of Flight Mechanics of the DLR has developed a helicopter in-flight simulator, called ATTHeS (Advanced Technology Testing Helicopter System). This in-flight simulator is used for control law design, handling qualities investigations and, in an operational mode, for test pilot training. An explicit model-following control system has been developed which meets the demands of high bandwidth and high flexibility. The essential steps, to obtain a satisfactory status of the control system are described in this paper. The first step was to define an appropriate mathematical model of the testbed BO 105, which includes rotor degrees of freedom to reduce time delays, as these are normally used to describe model deficiencies. The second step was to conduct flight tests with the testbed and then determine the parameters of the defined model by system identification. The third step was the inversion of the above-defined and identified model, and building up the tools for the calculation of the feedforward part of the model-following control system. In a fourth step the design and calculation of the feedback structure was conducted. This was done by intensive simulation runs and a final refinement in flight tests. The fifth and final step was to conduct many flight tests for the evaluation of the performance of the overall system, to make the in-flight simulator available for operational investigations.

ISSN:0020-7179    

DOI:10.1080/00207179408923077

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Over the last two decades, flight control system requirements have been in a state of transition. Rotary wing missions have become more demanding, requiring vehicle management systems capable of conducting highly aggressive missions under night/adverse-weather conditions in severe electromagnetic environments. The digital, fly-by-wire/optics control system technologies developed at Boeing Defense and Space Group, Helicopters Divison to meet these air vehicle requirements are covered. These technologies, which integrate digital multimode control laws and sidestick controllers within redundant-reconfigurable architectures, provide the rotorcraft capabilities required for the 21st century. The advances in flight control design, as developed during various technology demonstrator programmes, and applied in production of the V-22 Osprey tiltrotor and the RAH-66 Comanche scout/attack helicopter, are summarized.

ISSN:0020-7179    

DOI:10.1080/00207179408923078

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Future short take-off and vertical landing (STOVL) concepts present unique design challenges. The flight control system designer must consider several issues including the control response type, the appropriate cockpit displays, and the control strategy for the flight and propulsion controls. Advanced STOVL concepts will have many force and moment generators. To be operationally effective such configurations need to have precise handling and control properties such that the pilot is not faced with an unacceptably high workload. The vectored thrust aircraft advanced flight control (VAAC) is a research programme which is addressing these issues. Its primary objective is to develop flight control and handling concepts which, when applied to future STOVL configurations, will provide good handling qualities with a low pilot workload. Four potential methods of controlling future STOVL aircraft are described and assessed with manned simulation and with the VAAC Harrier aircraft.

ISSN:0020-7179    

DOI:10.1080/00207179408923079

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper presents a summary of experience in the design of velocity vector control systems for operation of short take-off and landing (STOL) and short take-off and vertical landing (STOVL) aircraft over their low-speed flight envelopes. A nonlinear inverse control method developed at NASA Ames Research Center was employed to deal with the highly nonlinear, multi-dimensional aerodynamic and propulsion system characteristics that are inherent in these aircraft. The method partitions the control system into a command element that is defined solely by the dynamic response to achieve good flying qualities, and a nonlinear inverse element that computes the aerodynamic and propulsion control effector positions required to satisfy the pilot's commands and to regulate against disturbances. Experience gained at flight evaluations with a powered-lift STOL aircraft and in piloted simulation with a STOVL aircraft design indicates that this system design approach produces the desired flying qualities over the low-speed flight envelope in the presence of a wide range of wind and turbulence disturbances.

ISSN:0020-7179    

DOI:10.1080/00207179408923080

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor