Near-minimum-time control of distributed parameter systems - Analytical and experimental results

Junkins, John L.; Rahman, Z.; Bang, Hyochoong

doi:10.2514/3.20653

Cited by 135 publications

(56 citation statements)

References 7 publications

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“…To avoid the instantaneous switches of the near-minimum-time bang-bang law, which, applied to exible systems, excite the poorly modeled higher modes, Junkins et al 7 proposed to use a continuous spline approximation of the sign function. It is here recalled that the bang-bang command gives the minimum-time control only in case of a rigid-body, single-axis control problem.…”

Section: B Command Smoothingmentioning

confidence: 99%

“…Song et al 6 treated the application of input shaping for reduction of vibration of a exible spacecraft, using pulse-width pulse-frequency-modulated thrusters. Another command shaping approach, whose principle is to smooth the bang-bang input with a spline approximationof the sign function, was proposed by Junkins et al 7 and studied by Hecht and Junkins to deal with the problem of near-minimum-time control of a exible manipulator. 8 Mimmi et al studied a different command shaping technique derived by the design of cam pro les.…”

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confidence: 99%

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Experiments on Command Shaping Control of a Manipulator with Flexible Links

Romano

Agrawal

Bernelli‐Zazzera

2002

Journal of Guidance, Control, and Dynamics

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Section: B Command Smoothingmentioning

confidence: 99%

mentioning

confidence: 99%

Experiments on Command Shaping Control of a Manipulator with Flexible Links

Romano

Agrawal

Bernelli‐Zazzera

2002

Journal of Guidance, Control, and Dynamics

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“…The 'near-minimum time' control scheme was originally proposed for large angle maneuvers of flexible spacecraft. 8,9) It is well known that this scheme enables a control law to avoid a large initial torque command with the benefit of rapid maneuvering. In the approach phase, it is ideal for an unmanned helicopter to descend to the specified altitude as fast as possible.…”

Section: Introductionmentioning

confidence: 99%

Lyapunov Control Law for Automatic Approach for Unmanned Helicopter Landing

Lee

Kim

Shin

et al. 2011

Trans. Japan Soc. Aero. S Sci.

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Describing the flight behavior of a helicopter is a difficult challenge in mathematical modeling. A rotorcraft can be considered as a complex arrangement of interacting subsystems, and the problem is dominated by rotor. The rotor blades bend and twist under the influence of unsteady and nonlinear aerodynamic loads, which are themselves a function of blade motion. This problem makes it more difficult to estimate the behavior of a helicopter. Furthermore, it is difficult to design a flight controller for unmanned helicopter systems. In this paper, to obtain a nonlinear dynamic model of a helicopter, parameter identification is performed using flight test data. A globally stable tracking control law for agile and precise landing of an unmanned helicopter is proposed. A near-minimum time control scheme is adopted to design the reference trajectory, and it is shown that the control law is guaranteed to be stable globally in the sense of Lyapunov. A flight test verified the performance of the proposed method. Performance can be improved by choosing the control parameters via optimization. The proposed method can be extended to a multiple output trajectory tracking problem for a precise fixed-wing UAV landing.

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“…As a result, the flexible modes limit the control bandwidth and degrade the pointing error at the end of slew maneuver, resulting in a longer settling time. So researchers over the years developed several shaping techniques to smooth the minimum-time solutions [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Method of Slewing the Spacecraft to Minimize Settling Time

Chen

Agrawal

2002

AIAA Guidance, Navigation, and Control Conference and Exhibit

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The low-frequency flexible modes of solar arrays on spacecraft are excited by the minimum-time bang-bang control during a slew maneuver. These flexible modes limit the control bandwidth and degrade the pointing error at the end of slew maneuver, resulting in a longer settling time. The objective of this investigation is to develop and verify methods to shape the torque profile of reaction wheels for the slew maneuver such that, at the end of slew, vibration are minimized and the settling time is reduced. Effectiveness of the smooth versine input profiles, torque feedforward, and input shaping are accessed. Both numerical simulation results and ground simulated experimental results are presented in this paper.

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Near-minimum-time control of distributed parameter systems - Analytical and experimental results

Cited by 135 publications

References 7 publications

Experiments on Command Shaping Control of a Manipulator with Flexible Links

Experiments on Command Shaping Control of a Manipulator with Flexible Links

Lyapunov Control Law for Automatic Approach for Unmanned Helicopter Landing

Method of Slewing the Spacecraft to Minimize Settling Time

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