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Designing feedback compensators by using the Root-Locus methodKorkmaz, Levent 12 1900 (has links)
Approved for public release; distribution is unlimited / The purpose of this thesis is to find suitable ways to design feedback compensators for high order systems by using Root-Locus methods.
As a starting point we will examine a motor amplidyne system and a position control system that were previously designed using Bode methods. Then we generalize the method and extend it to other systems.
The final subject of this thesis is to design feedback compensators as filters by using state feedback coefficients to define zeros of the filter, then we extend this idea to build cascade filters. / http://archive.org/details/designingfeedbac00kork / Lieutenant, Junior Grade, Turkish Navy
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Robust Control for Offshore Steel Jacket Platforms under Wave-Induced ForcesDongsheng, Han, rising_sun_han@hotmail.com January 2008 (has links)
This thesis is concerned with robust control of an offshore steel jacket platform
subject to nonlinear wave-induced forces. Since time delay and uncertainty are
inevitably encountered for an offshore structure and their existence may induce instability, oscillation and poor performance, it is very significant to study on how the
delay and uncertainty affect the offshore structure. In this thesis, a memory robust
control strategy is, for the first time, proposed to reduce the internal oscillations
of the offshore structure under wave-induced forces, so as to ensure the safety and
comfort of the offshore structure.
Firstly, when the system's states are adopted as feedback, memory state feedback
controllers are introduced for the offshore structure. By using Lyapunov-Krasovskii
stability theory, some delay-dependent stability criteria have been established, based
on which, and by combining with some linearization techniques, memory state feedback controllers are designed to control the offshore structure. The simulation results show that such controllers can effectively reduce the internal oscillations of the
offshore structure subject to nonlinear wave-induced forces and uncertainties. On
the other hand, a new Lyapunov-Krasovskii functional is introduced to derive a less
conservative delay-dependent stability criterion. When this criterion is applied to
the offshore structure, an improved memory state feedback controller with a small
gain is obtained to control the system more effectively, which is sufficiently shown
by the simulation.
Secondly, when the system's outputs are adopted as feedback, memory dynamic
output feedback controllers are considered for the offshore structure. By employing
a projection theorem and a cone complementary linearization approach, memory
dynamic output feedback controllers are derived by solving some nonlinear minimization problem subject to some linear matrix inequalities. The simulation results
show that the internal oscillations of the offshore structure subject to nonlinear
wave-induced forces are well attenuated.
Finally, robust H control is fully investigated for the offshore structure. By employing Lyapunov-Krasovskii stability theory, some delay-dependent bounded real
lemmas have been obtained, under which, via a memory state feedback controller or
a dynamic output feedback controller, the resulting closed-loop system is not only
asymptotically stable but also with a prescribed disturbance attenuation level. The
simulation results illustrate the validity of the proposed method.
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Stabilization and Performance Improvement of Control Systems under State FeedbackYao, Lisha 05 1900 (has links)
The feedback control system is defined as the sampling of an output signal and feeding it back to the input, resulting in an error signal that drives the overall system. This dissertation focuses on the stabilization and performance of state feedback control systems. Chapters 3 and 4 focus on the feedback control protocol approaching in the multi-agents system. In particular, the global regulation of distributed optimization problems has been considered. Firstly, we propose a distributed optimization algorithm based on the proportional-integral control strategy and the exponential convergence rate has been delivered. Moreover, a decentralized mechanism has been equipped to the proposed optimization algorithm, which enables an arbitrarily chosen agent in the system can compute the value of the optimal solution by only using the successive local states. After this, we consider the cost function follows the restricted secant inequality. A dynamic event-triggered mechanism design has been proposed. By ensuring the global regulation of the distributed proportional-integral optimization algorithm, the dynamic event-triggered mechanism efficiently reduces the communication frequency among agents. Chapter 5 focuses on the feedback control protocol approaching the single-agent system. Specifically, we investigate the truncated predictor feedback control of the regulation of linear input-delayed systems. For the purpose of improving the closed-loop performance, we propose a design of the truncated predictor feedback method with time-varying feedback parameters and give the potential range of choosing the time-varying feedback parameters to replace the traditional constant low gain parameters.
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ANALYSIS AND CONTROL OF BIFURCATIONS IN A DOUBLE PENDULUMJAFRI, FIROZ ALI 17 April 2003 (has links)
No description available.
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Analysis of a GSVD Approach to Full-State Feedback Control Design Using Singular Value Localization of EigenvaluesWo, Siew Mun January 1989 (has links)
No description available.
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Longitudinal Vehicle Speed Controller for Autonomous Driving in Urban Stop-and-Go Traffic SituationsSawant, Neil Ravindra 02 November 2010 (has links)
No description available.
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K-modification and a novel approach to output feedback adaptive controlKim, Kilsoo 04 April 2011 (has links)
This dissertation presents novel adaptive control laws in both state feedback and output feedback forms. In the setting of state feedback adaptive control K-modification provides a tunable stiffness term that results in a frequency dependent filtering effect, smoother
transient responses, and time delay robustness in an adaptive system. K-modification
is combined with the recently developed Kalman filter (KF) based adaptive control and
derivative-free (DF) adaptive control. K-modification and its combinations with KF adaptive
control and DF adaptive control preserve the advantages of each of these methods and
can also be combined with other modification methods such as - and e-modification. An
adaptive output feedback control law based on a state observer is also developed. The main
idea behind this approach is to apply a parameter dependent Riccati equation to output
feedback adaptive control. The adaptive output feedback approach assumes that a state
observer is employed in the nominal controller design. The observer design is modified
and employed in the adaptive part of the design in place of a reference model. This is
combined with a novel adaptive weight update law. The weight update law ensures that
estimated states follow both the reference model states and the true states so that both
state estimation errors and state tracking errors are bounded. Although the formulation is
in the setting of model following adaptive control, the realization of the adaptive controller
uses the observer of the nominal controller in place of the reference model to generate an
error signal. Thus the only components that are added by the adaptive controller are the
realizations of the basis functions and the weight adaptation law. The realization is even
less complex than that of implementing a model reference adaptive controller in the case of
state feedback. The design procedure of output feedback adaptive control is illustrated with
two examples: a simple wingrock dynamics model and a more complex aeroelastic aircraft
transport model.
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Point-of-load converters for a residential dc distribution systemDesai, Harshad Suresh 09 July 2012 (has links)
This thesis studies residential dc distribution system with primary focus on point-of-load (POL) converters. The growing number of inherently dc loads, increasing penetration of distributed energy resources (DERs) and advancements in power electronic converters are some of the reasons to reconsider the existing residential ac distribution system. A dc distribution system can achieve higher efficiency by eliminating the ac-dc rectifiers and power factor correction stages currently used in most domestic electronic appliances. In this thesis, 380V is identified as a suitable voltage level for the main dc bus. Safety issues are discussed and common domestic loads are characterized. Two common converter topologies – buck and flyback converters are suggested as POL converters for heating and LED lighting loads respectively. State-feedback control is designed and implemented for buck converter and current mode control of flyback converter is implemented. A 500W POL buck converter using state-feedback with integral control is designed and tested for heating load applications. Finally a small dc distribution system is simulated using the converter models. The response of the system is stable under load and line changes. / text
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Missile Autopilot Design By Projective Control TheoryDoruk, Resat Ozgur 01 January 2003 (has links) (PDF)
In this thesis, autopilots are developed for missiles with moderate dynamics and
stationary targets. The aim is to use the designs in real applications. Since the real
missile model is nonlinear, a linearization process is required to get use of systematic
linear controller design techniques. In the scope of this thesis, the linear quadratic
full state feedback approach is applied for developing missile autopilots. However,
the limitations of measurement systems on the missiles restrict the availability of all
the states required for feedback. Because of this fact, the linear quadratic design will
be approximated by the use of projective control theory. This method enables the
designer to use preferably static feedback or if necessary a controller plus a low
order compensator combination to approximate the full state feedback reference.
Autopilots are checked for the validity of linearization, robust stability against
aerodynamic, mechanical and measurement uncertainties.
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Experimental Validation of a Numerical Controller Using Convex Optimization with Linear Matrix Inequalities on a Quarter-Car Suspension SystemChintala, Rohit 2011 August 1900 (has links)
Numerical methods of designing control systems are currently an active area of research. Convex optimization with linear matrix inequalities (LMIs) is one such method. Control objectives like minimizing the H_2, H_infinity norms, limiting the actuating effort to avoid saturation, pole-placement constraints etc., are cast as LMIs and an optimal feedback controller is found by making use of efficient interior-point algorithms. A full-state feedback controller is designed and implemented in this thesis using this method which then forms the basis for designing a static output feedback (SOF) controller. A profile was generated that relates the change in the SOF control gain matrix required to keep the same value of the generalized H_2 norm of the transfer function from the road disturbance to the actuating effort with the change in the sprung mass of the quarter-car system. The quarter-car system makes use of a linear brushless permanent magnet motor (LBPMM) as an actuator, a linear variable differential transformer (LVDT) and two accelerometers as sensors for feedback control and forms a platform to test these control methodologies.
For the full-state feedback controller a performance measure (H_2 norm of the transfer function from road disturbance to sprung mass acceleration) of 2.166*10^3 m/s^2 was achieved ensuring that actuator saturation did not occur and that all poles had a minimum damping ratio of 0.2. The SOF controller achieved a performance measure of 1.707*10^3 m/s^2 ensuring that actuator saturation does not occur. Experimental and simulation results are provided which demonstrate the effectiveness of the SOF controller for various values of the sprung mass. A reduction in the peak-to-peak velocity by 73 percent, 72 percent, and 71 percent was achieved for a sprung mass of 2.4 kg, 2.8 kg, and 3.4 kg, respectively. For the same values of the sprung mass, a modified lead-lag compensator achieved a reduction of 79 percent, 77 percent and, 69 percent, respectively. A reduction of 76 percent and 54 percent in the peak-to-peak velocity was achieved for a sprung mass of 6.0 kg in simulation by the SOF controller and the modified lead-lag compensator, respectively. The gain of the modified lead-lag compensator needs to be recomputed in order to achieve a similar attenuation as that of the SOF controller when the value of the sprung mass is changed. For a sprung mass of 3.4 kg and a suspension spring stiffness of 1640 N/m the peak-to-peak velocity of the sprung mass was attenuated by 42 percent.
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