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Ultimate Boundedness Theorem for Model Reference Adaptive control Systems

JOURNAL OF GUIDANCE control AND DYNAMICS 2014年第5期37卷 1595-1603页

作者： Hoecht, L. Bierling, T. Holzapfel, F. Tech Univ Munich Inst Flight Syst Dynam D-85748 Garching Germany

This paper presents a novel formulation of the Lyapunov-based ultimate boundedness theorem with explicit specification of transient and ultimate bounds, time to the ultimate bound, and the set of admissible initial conditions. The formulation is tailored to the structure of model reference adaptive control systems accounting for a partitioning of the state vector into a tracking error and a parameter estimation error. It allows for a computation of separate bounds for the single state vector partitions in favor of a single bound on the compound state, consisting of both partitions. This is of great practical importance because tracking error and parameter estimation error are of different magnitudes in general. Regarding model reference adaptive control systems, it is the state of the technology so far that the ultimate boundedness theorem is tailored to the structure of the considered system each time, again and again. It is hence manifest to formulate once a generic version of the theorem, tailored to model reference adaptive control systems, but not to reinvent the wheel for each case.

关键词： Model Reference Adaptive control Elevator Deflection Flight control System Adaptive control Systems Aviation Unmanned Aircraft System Second Order Differential Equations Attitude Stabilization Handling Qualities control algorithm

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Guidance and control of Airplanes Under Actuator Failures and Severe Structural Damage

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JOURNAL OF GUIDANCE control AND DYNAMICS 2013年第4期36卷 1093-1104页

作者： Chowdhary, Girish Johnson, Eric N. Chandramohan, Rajeev Kimbrell, M. Scott Calise, Anthony Georgia Inst Technol Sch Aerosp Engn Atlanta GA 30318 USA

This paper presents control algorithms for guidance and control of airplanes under actuator failures and severe structural damage. The presented control and guidance algorithms are validated through experimentation on the Georgia Institute of Technology Twinstar twin engine, fixed-wing, unmanned aerial system. Damage scenarios executed include sudden loss of all aerodynamic actuators resulting in propulsion-only flight, 25% of the left wing missing, sudden loss of 50% of the right wing and aileron in-flight, and injected actuator time delay. A state-dependent guidance logic is described that ensures the aircraft tracks feasible commands in the presence of faults. The commands are used by an outer-loop linear controller to generate feasible attitude commands. The inner-loop attitude control can be achieved by using either a linear attitude controller or a neural network-based model reference adaptive controller. The results indicate the possibility of using control methods to ensure safe autonomous flight of transport aircraft through validation on a scaled model that has characteristics of a typical transport category aircraft.

关键词： Structural Damage Transport Aircraft Actuators Roll control control Guidance Safe Autonomous Flight Attitude Guidance control algorithm Aircraft Tracking Unmanned Aerial Systems

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TEST BENCH FOR ROTORCRAFT HOVER control

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JOURNAL OF GUIDANCE control AND DYNAMICS 1994年第4期17卷 729-736页

作者： WEILENMANN, MF GEERING, HP SWISS FED INST TECHNOL MEASUREMENT & CONTROL LABCH-8092 ZURICHSWITZERLAND

This paper describes an indoor stand for a computer-controlled model helicopter. This stand was built to verify modern multivariable controller algorithms in real-world tests rather than in simulations. A commercial radio-controlled helicopter (not a scale model) is mounted on a mechanical structure allowing 6-degree of freedom flight conditions in a 2-m cube. The symmetrical geometry of the frame reduces its physical influence on the rotorcraft to be equivalent to a concentrated mass near the center of gravity. Including the dynamics of the driving motor and some unsteady aspects of the aerodynamics, an unstable 18th order mathematical model results. In addition, the radio controller causes a significant time delay. For this system, several control algorithms have been applied [channelwise proportional differential (PD) controller used for system identification, Linear Quadratic Gaussian/Loop Transfer Recovery (LQG/LTR) approaches, modal controller]. The quality of the test results and some aspects of design problems are described and compared in the second part of the paper.

关键词： Rotorcraft Hover control Helicopters Open Loop Transfer Function Linear Quadratic Gaussian Mathematical Models Aerodynamic Force RC Model control algorithm Yaw Cyclic Stick

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Research on the automatically trajectory control of a spherical isolation plug in subsea pipeline

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OCEAN ENGINEERING 2017年 141卷 101-107页

作者： Zhu, Xiaoxiao Wang, Hao Li, Fengqin Quan, Yi Wang, Wenming Zhang, Shimin China Univ Petr Coll Mech & Transportat Engn Beijing 102249 Peoples R China

The rapid growth demanding for oil and gas resources has gradually driven the fossil energy exploitation from the land to the ocean. Technology shifts from manually operated oil fields to the remotely operated oil fields is necessary, and robotic assistance to human cognition is essential. Hot tapping and line stop techniques, as a great method for the replacement of the risky pipelines without disrupting the service to customers, demands for the automation to improve the efficiency and reliability. In this paper, automatically trajectory control of a spherical isolation plug in subsea pipeline was investigated. Mathematical model for the spherical plug head insertion was presented, and two control algorithms for the automatically insertion of the plug were proposed, named the rotation angle based control algorithm and the vertical displacement based control algorithm. Simulation was conducted and the results indicate that the vertical displacement based control algorithm owes better performance than the rotation angle based control algorithm. The accuracy and efficiency of the vertical displacement based control algorithm was then experimentally researched. The results in this paper can provide references for the automatically trajectory control of an isolation plug, as well as improve the accuracy and reliability of offshore hot tapping.

关键词： Subsea pipeline maintenance Spherical isolation plug Insertion trajectory control algorithm Geometrical modeling

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Constrained Attitude control on SO(3) via Semidefinite Programming

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JOURNAL OF GUIDANCE control AND DYNAMICS 2018年第11期41卷 2483-2488页

作者： Walsh, Alex Forbes, James Richard Univ Michigan Dept Aerosp Engn Francois Xavier Bagnound Bldg1320 Beal Ave Ann Arbor MI 48109 USA McGill Univ Dept Mech Engn Macdonald Engn Bldg817 Sherbrooke St West Montreal PQ H3A 0C3 Canada

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Generalized holds, ripple attenuation, and tracking additional outputs in learning control

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JOURNAL OF GUIDANCE control AND DYNAMICS 1997年第6期20卷 1207-1214页

作者： Longman, RW Lo, CP Columbia University New York New York 10027

Iterative discrete-time learning control can be very effective at improving the tracking performance of control systems, Three different limitations or potential difficulties of discrete-time learning control are addressed. 1) The number of output variables for which zero tracking error can be achieved is limited by the number of input variables. 2) Every variable for which zero tracking error is sought must be a measured variable. 3) Because the control action is digital, the intersample behavior may have undesirable error from ripple. The first issue is addressed by two approaches, either by seeking zero error for different output variables at alternating time steps or by skipping time steps, The latter corresponds to using a generalized hold device, To address the second issue, it is shown how these techniques can be combined with an observer when one wishes to have improved tracking of not only measured outputs but also unmeasured output variables. To improve ripple, one can ask for good tracking of the output, and in addition good tracking of its derivative or derivatives, and it is shown how methods developed here can accomplish this, These generalizations are made for three different effective learning control laws: integral control-based learning with zero phase filtering, which is particularly simple;a contraction mapping learning control, which Is particularly robust;and a phase cancellation learning control, which is particularly effective at producing small final error levels in experiments.

关键词： Single Input Single Output System Iterative Learning control Robots Feedback control System Robotics Research Corporation Large Angle Maneuver control algorithm Quadratic Programming Robotics

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An adaptative control strategy for interfacing converter of hybrid microgrid based on improved virtual synchronous generator

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IET RENEWABLE POWER GENERATION 2022年第2期16卷 261-273页

作者： Zhang, Liang Wang, Xuesong Zhang, Zhe Cui, Ying Ling, Lyu Cai, Guowei Northeast Elect Power Univ Minist Educ Key Lab Modern Power Syst Simulat & Control & Ren Jilin 132012 Jilin Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore Guangdong Elect Power Corp Zhuhai Power Supply Bur Zhuhai 519000 Peoples R China

Inertial support for hybrid AC/DC microgrid systems is provided by the virtual synchronous generator (VSG). However, the fast performance of the system is neglected while enhancing the stability of the system. To address this problem, an adaptive virtual inertia control strategy based on VSG technology is proposed. This control approach adaptively adjusts the system virtual inertia when the system operation deviates from the nominal value, by slowing down the rate of change of AC frequency and DC voltage and improving the deviation of AC frequency and DC voltage. Meanwhile, when the AC frequency and DC voltage restore back to the rated value, the rate of change of AC frequency is accelerated and the DC voltage fluctuation is reduced by dynamically adjusting the virtual inertia of the system. The proposed adaptive virtual inertia control method combines the advantages of large and small inertia to effectively improve the dynamic response of the system voltage and frequency in both rectifier and inverter modes. Finally, the simulation and experimental results verify the effectiveness of the proposed control algorithm.

关键词： adaptive virtual inertia control strategy rated value power generation control distributed power generation system virtual inertia system operation deviates adaptive control control algorithm control approach synchronous generators power grids VSG technology virtual inertia control method adaptative control strategy hybrid microgrid power system control invertors AC frequency improved virtual synchronous generator DC voltage fluctuation power system stability system voltage

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Manufacturing and control of a Robotic Device for Time-averaged Simulated Micro and Partial Gravity of a Cell Culture Environment

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INTERNATIONAL JOURNAL OF control AUTOMATION AND SYSTEMS 2020年第1期18卷 53-64页

作者： Kim, Yoon Jae Lim, Min Hyuk Jeon, Byoungjun Choi, Dong Hyun Lee, Haeri Jeong, Ae Jin Kim, Min Jung Park, Ji Won Ku, Ja-Lok Jeong, Seung-Yong Ye, Sang-Kyu Kim, Youdan Kim, Sungwan Seoul Natl Univ Inst Med & Biol Engn Seoul 03080 South Korea SNU Coll Med Dept Biomed Engn Seoul 03080 South Korea SNU Interdisciplinary Program Bioengn Seoul 03080 South Korea SNU Coll Med Dept Pharmacol & Biomed Sci Seoul 03080 South Korea Seoul Natl Univ Hosp Dept Surg Seoul 03080 South Korea SNU Coll Med Dept Biomed Sci Seoul 03080 South Korea SNU Coll Med Dept Surg Seoul 03080 South Korea SNU Coll Engn Dept Mech & Aerosp Engn Seoul 08826 South Korea

Gravity is omnipresent for all objects on Earth. However, in an environment of different gravitational stress (e.g., microgravity or partial gravity), cells and organs show different biological responses. So, researchers have attempted to achieve micro- or partial gravity on Earth through various approaches, such as parabolic flight or free fall. However, the duration of such ground experiments is highly limited, making it very difficult to conduct time-consuming tasks, such as cell culture. Thus, a three-dimensional (3D) clinostat is utilized as an alternative for experiments on the International Space Station. It provides time-averaged simulated micro- and partial gravity by using mechanical frames with two rotating actuators. This study proposes novel control algorithms for simulating micro- and partial gravity and validates them by applying it to the control of a manufactured 3D clinostat. First, the novel algorithm for time-averaged simulated microgravity (taSMG) provided a more uniformly distributed gravity field by reducing two poles the gravity-concentrated areas. The taSMG with reduced poles provides isotropic gravitational patterns, from which it is possible to minimize the unnecessary effect due to nonuniformity of the gravity vector direction. Second, the other suggested novel algorithm for time-averaged simulated partial gravity (taSPG) controls the pole sizes asymmetrically to generate the intended size of partial gravity. The suggested algorithms are based on mathematical models rather than totally randomized motions. Therefore, the convergence of gravity values, in the rotating frame over time, can be analytically predicted with improved accuracy compared with previously reported algorithms. The developed 3D clinostat hardware and algorithms will effectively provide well-validated taSMG and taSPG for cell growth experiments in future studies for space medicine.

关键词： Cell culture clinostat control algorithm microgravity partial gravity space medicine

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Discretized Constrained Attitude Pathfinding and control for Satellites

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JOURNAL OF GUIDANCE control AND DYNAMICS 2013年第5期36卷 1301-1309页

作者： Kjellberg, Henri C. Lightsey, E. Glenn Univ Texas Austin Dept Aerosp Engn & Engn Mech Austin TX 78712 USA

A general purpose guidance, navigation, and control algorithm is developed for satellites with three degree-of-freedom rotation maneuverability. The algorithm is capable of meeting multiple pointing constraints autonomously by using a combination of constrained attitude pathfinding and control elements. The unit sphere is discretized into a graph using an icosahedron-based pixelization subroutine. An admissible path between attitude keep-out zones is found with the A* pathfinding algorithm. The trajectory is followed using a rate and torque constrained quaternion feedback controller. The algorithm is capable of running in real time on a low-power flight computer. An embedded version of the algorithm has secured flight opportunities on two student-built three-unit CubeSats. Both sets of mission requirements are satisfied with the same three-unit CubeSat attitude control system, demonstrating the algorithm's versatility as a general purpose controller. The autonomy provided by the constrained control algorithm enables more complex satellite missions to be performed and decreases the cost of spacecraft subsystems by shifting requirements away from the hardware and onto the control algorithm.

关键词： Small Satellites Attitude control System Quaternions control algorithm Three Degrees of Freedom Flight Computer Spacecraft Subsystem Spacecraft Attitude Cosmic Background Explorer Gyroscopes

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Recent control Technologies for Floating Offshore Wind Energy System: A Review

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INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING-GREEN TECHNOLOGY 2021年第1期8卷 281-301页

作者： Ha, Kwangtae Hoai Vu Anh Truong Tri Dung Dang Ahn, Kyoung Kwan Univ Ulsan Dept Floating Offshore Wind Energy Syst 93 Deahak Ro Ulsan 44610 South Korea Univ Ulsan Dept Mech Engn 93 Deahak Ro Ulsan 44610 South Korea Ho Chi Minh City Univ Technol & Educ Dept Mechatron Ho Chi Minh City 700000 Vietnam

This paper presents the recent control technologies being researched for floating offshore wind energy system (FOWES). FOWES has been getting many attentions recently as an alternative energy system utilizing vast sustainable wind resource away from land with little restriction by human societies, artificial and natural obstacles. However, not only due to the harsh environmental conditions such as strong wind, wave, and current, but also due to the platform motions such as surge, sway, heave, pitch, roll, and yaw, there could occur many problems including less energy capture than expected, frequent emergency stops, turbine structural instability, and fatigues resulting in early failures, which stay the levelized cost of energy (LCOE) still high compared to conventional fixed offshore wind energy system. These risks could be lowered by operating the turbine close to the optimum point and harvesting wind energy efficiently even under strong wind conditions with the properly applied control technologies, while reducing the loads on structural components. Many researches have been actively going on not only by numerical approaches, but also by experimental tests. This study is wrapping the most recent researches on control technologies for promising floating offshore wind energy system according to different substructure designs such as a spar type, semi-submergible type, tension-leg platform (TLP) type, and barge type, and discusses about its challenges as well.

关键词： Green technology Floating offshore wind energy system (FOWES) Substructures control algorithm Individual pitch control (IPC) Collective pitch control (CPC)

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