Track-Following Controller Design for a Compound Disk Drive Actuator

1990 ◽  
Vol 112 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Jia-Yush Yen ◽  
Kurt Hallamasek ◽  
Roberto Horowitz
Keyword(s):  
Transfer Functions ◽  
Controller Design ◽  
Tracking Error ◽  
Disk Drive ◽  
The State ◽  
Linear Quadratic ◽  
Parameter Uncertainties ◽  
Loop Transfer Recovery ◽  
Servo Actuator ◽  
Reference Track

The use of compound actuators in both magnetic and optical disk files has become a means of achieving increased servo actuator bandwidths. A compound actuator, comprised of a fine actuator mounted “piggyback” on a coarse actuator, positions the read/write transducers above a radial track. This paper describes a design methodology for a discrete-time feedback control system for a compound actuator in which the dynamic interaction between the actuator stages is directly considered. The performance of the servosystem, including the range and bandwith limitations of each actuator, is specified in terms of the desired frequency response of the closed-loop transfer functions from the reference track position to the tracking error and to the relative position between the coarse and the fine actuator. Parameter uncertainties and structural resonances are quantified using singular value techniques to form a robustness criterion which sets limits on the attainable tracking performance. Compensator design techniques using linear-quadratic Gaussian optimal control combined with loop transfer recovery are described. The state feedback portion of the compensator is calculated using an automatic procedure, while the state estimator is calculated by solving an associated Kalman filtering problem with colored fictitious noise. The noise is colored to shape the frequency spectrum of the input energy to each actuator, the relative motion between the stages, and the position of the transducer.

scholarly journals Strain Sensing With Piezoelectric Zinc Oxide Thin Films for Vibration Suppression in Hard Disk Drives

2008 ◽  
Author(s):  
Sarah Felix ◽  
Stanley Kon ◽  
Jianbin Nie ◽  
Roberto Horowitz
Keyword(s):  
Vibration Suppression ◽  
Transfer Functions ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Strain Sensing ◽  
Linear Quadratic ◽  
H2 Control ◽  
Hard Drives ◽  
Optimization Methodology

This paper describes the integration of thin film ZnO strain sensors onto hard disk drive suspensions for improved vibration suppression for tracking control. Sensor location was designed using an efficient optimization methodology based on linear quadratic gaussian (LQG) control. Sensors were fabricated directly onto steel wafers that were subsequently made into instrumented suspensions. Prototype instrumented suspensions were installed into commercial hard drives and tested. For the first time, a sensing signal was successfully obtained while the suspension was flying on a disk as in normal drive operation. Preliminary models were identified from experimental transfer functions. Nominal H2 control simulations demonstrated improved vibration suppression as a result of both the better resolution and higher sensing rate provided by the sensors.

Reduced-Order Model-Based Feedback Control of Flow Over an Obstacle Using Center Manifold Methods

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Coşku Kasnakoğlu ◽  
R. Chris Camphouse ◽  
Andrea Serrani
Keyword(s):  
Boundary Control ◽  
Center Manifold ◽  
Controller Design ◽  
Tracking Error ◽  
Reduced Order Model ◽  
Order System ◽  
Linear Quadratic ◽  
Order Model ◽  
Control Effort ◽  
Reduced Order

In this paper, we consider a boundary control problem governed by the two-dimensional Burgers’ equation for a configuration describing convective flow over an obstacle. Flows over obstacles are important as they arise in many practical applications. Burgers’ equations are also significant as they represent a simpler form of the more general Navier–Stokes momentum equation describing fluid flow. The aim of the work is to develop a reduced-order boundary control-oriented model for the system with subsequent nonlinear control law design. The control objective is to drive the full order system to a desired 2D profile. Reduced-order modeling involves the application of an L2 optimization based actuation mode expansion technique for input separation, demonstrating how one can obtain a reduced-order Galerkin model in which the control inputs appear as explicit terms. Controller design is based on averaging and center manifold techniques and is validated with full order numerical simulation. Closed-loop results are compared to a standard linear quadratic regulator design based on a linearization of the reduced-order model. The averaging∕center manifold based controller design provides smoother response with less control effort and smaller tracking error.

Dynamic-free robust adaptive intelligent fault-tolerant controller design with prescribed performance for stable motion of quadruped robots

2019 ◽  
pp. 105971231989069 ◽  
Author(s):  
Yousef Farid ◽  
Vahid Johari Majd ◽  
Abbas Ehsani-Seresht
Keyword(s):  
Controller Design ◽  
Fault Tolerant ◽  
Tracking Error ◽  
Lyapunov Stability Theory ◽  
Quadruped Robot ◽  
Parameter Uncertainties ◽  
Prescribed Performance ◽  
Quadruped Robots ◽  
Full State Feedback ◽  
Robust Adaptive

In this article, a robust adaptive intelligent fault-tolerant controller with prescribed performance is proposed for an uncertain quadruped robot with actuator fault. The control system comprised of three terms: (1) a full-state feedback controller which includes the prescribed performance function, (2) an adaptive intelligent wavelet-based Takagi-Sugeno fuzzy network (TSFN), and (3) a robust control term. The proposed controller does not utilize the robot dynamic model. A wavelet-based TSFN is utilized to approximate adaptively the lumped nonlinear terms, parameter uncertainties, and defective torque signal. The wavelet block acts as a feature extractor, reduces the number of fuzzy rules, and also acts as a normalization function. The parameters of TSFN are tuned online by an adaptive law based on Lyapunov stability theory. The proposed controller guarantees the desired specification such as minimum speed of convergence, maximum steady-state error, overshoot concerning the position tracking error, and also bounded closed-loop signals. Numerical simulations on MATLAB/SimMechanics environment demonstrate the stable walking of the quadruped robot in the presence of the actuator faults and parameter uncertainties.

System Identification and Multivariate Controller Design for a Satellite Ultraquiet Isolation Technology Experiment (SUITE)

2002 ◽  
Author(s):  
Alok A. Joshi ◽  
Won-jong Kim
Keyword(s):  
Vibration Isolation ◽  
Transfer Functions ◽  
Controller Design ◽  
Input Output ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input ◽  
Six Degree Of Freedom

A mathematical model of a six-degree-of-freedom hexapod system for vibration isolation was derived in the discrete-time domain on the basis of the experimental data obtained from a satellite. Using Box-Jenkins model structure, the transfer functions between six piezoelectric actuator input voltages and six geophone sensor output voltages are identified empirically. The 6×6 transfer function matrix is symmetric, and its off-diagonal terms indicate the coupling among different input/output channels. Though the coupling was observed among various input/output channels up to 10 Hz, the single-input single-output (SISO) controllers were designed neglecting the effect of coupling. The SISO controllers demonstrated limited performance in vibration attenuation. Using multi-input multi-output (MIMO) control techniques such as Linear Quadratic Gaussian (LQG) and H∞, high-order controllers were developed. The simulation results using these controllers obtain 33 dB, and 12 dB attenuation at 5, and 25 Hz corner frequencies, respectively.

Optimal H∞-Based Linear-Quadratic Regulator Tracking Control for Discrete-Time Takagi–Sugeno Fuzzy Systems With Preview Actions

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Hui Zhang ◽  
Yang Shi ◽  
Bingxian Mu
Keyword(s):  
Discrete Time ◽  
Tracking Control ◽  
Design Problem ◽  
Fuzzy Systems ◽  
State Feedback ◽  
Controller Design ◽  
Tracking Error ◽  
The State ◽  
Control Signal ◽  
Takagi Sugeno

This paper investigates the optimal tracking control problem for discrete-time Takagi–Sugeno (T–S) systems. The control signal has three components: preview control for the previewable reference signal, integral control for the tracking error, and the state-feedback control for the plant. The optimization objective is a quadratic form of the tracking error and the control signal. By using the augmentation technique, the tracking controller design problem is converted into a design problem of the state-feedback controllers for augmented T–S fuzzy systems. The quadratic optimization objective is equivalent to the two-norm (in fact, the square of the two-norm) of a controlled output. Assuming that the external inputs of the augmented systems are l2 bounded, the H∞ performance index is employed to investigate and optimize the controller design. The controller gains can be obtained by solving a sequence of linear matrix inequalities (LMIs). An example on electromechanical system shows the efficacy of the proposed design method.

Preview Control for Vehicle Lateral Guidance in Highway Automation

1993 ◽  
Vol 115 (4) ◽  
pp. 679-686 ◽  
Author(s):  
Huei Peng ◽  
Masayoshi Tomizuka
Keyword(s):  
Frequency Domain ◽  
Control Algorithm ◽  
Controller Design ◽  
Feedforward Control ◽  
Design Method ◽  
Tracking Error ◽  
Ride Quality ◽  
Linear Quadratic ◽  
Preview Control ◽  
Control Approach

The continuous time deterministic optimal preview control algorithm is applied to the lateral guidance of a vehicle for an automated highway. In the lateral guidance problem, the front wheel steering angle of the vehicle is controlled so that the vehicle follows the center for a lane with small tracking error and maintains good ride quality simultaneously. A preview control algorithm is obtained by minimizing a quadratic performance index which includes terms representing the passenger ride quality as well as the lateral tracking error, each of these terms is multiplied by a frequency dependent weight. This design method is known as a frequency shaped linear quadratic (FSLQ) optimal control approach. It permits incorporating frequency domain design specifications such as high frequency robustness and ride quality in the optimal controller design. It is shown that the optimal preview control law consists of a feedback control term and two feedforward control terms. The feedback term is exactly the same as that of traditional LQ control algorithm. The feedforward preview control action significantly improves the tracking performance and ride quality. Frequency-domain analyses, as well as numerical simulation results, show the improvements achieved by using the preview control algorithm in both the frequency and time domains.

scholarly journals Linear Quadratic Optimal Controller Design for Constant Downstream Water-Level PI Feedback Control of Open-Canal Systems

2018 ◽  
Vol 246 ◽  
pp. 01056 ◽  
Author(s):  
Ke Zhong ◽  
Guanghua Guan ◽  
Zhonghao Mao ◽  
Wenjun Liao ◽  
Changcheng Xiao ◽  
...  
Keyword(s):  
Feedback Control ◽  
Objective Function ◽  
Water Level ◽  
Flow Rate ◽  
Controller Design ◽  
Linear Time ◽  
The State ◽  
Linear Quadratic ◽  
Linear Time Invariant ◽  
Canal Systems

The key point of PI feedback control is how to design appropriate controller parameters. This paper combined the linear quadratic optimizing control theory to design an online controller for constant downstream water-level operation which could respond to different working condition properly and rapidly avoiding complex controller parameters adjusting. Based on the Integrator-Delay (ID) model simplified from Saint-Venant Equations, we established the discretized linear time invariant system of canals. Then transferred it into the state-space equations and obtained the state-feedback equation. Water level deviations and flow rate increments were chosen to form the objective function and this paper recommended values of Q and R weight matrices among it should be set according to the optimum quadratic form indicators correspondingly. This controller was applied to two practical canal systems which had diverse scales. Results showed the system under control quickly regained stability; optimizing the objective function with recommended weight matrices could well balance demands on water level deviations and flow rate changes; dynamic performances of water movements and gate movements were acceptable. Through simulations, we preliminarily proved the practicability of this online PI controller implementing LQR. This work proposed an available solutions for the design and operation of water conveyance systems around the world.

scholarly journals Semitrailer Steering Control for Improved Articulated Vehicle Manoeuvrability and Stability

2019 ◽  
Vol 8 (1) ◽  
pp. 568-581
Author(s):  
Sina Milani ◽  
Y. Samim Ünlüsoy ◽  
Hormoz Marzbani ◽  
Reza N. Jazar
Keyword(s):  
High Speed ◽  
Controller Design ◽  
Tracking Error ◽  
Linear Quadratic Regulator ◽  
State Feedback Control ◽  
Steering Control ◽  
Linear Quadratic ◽  
Amplification Ratio ◽  
Vehicle Dynamic Simulation ◽  
Optimal State Feedback

Abstract Articulated heavy vehicles have some specific performance limitations and safety risks due to their special dynamic characteristics. They show poor manoeuvrability at low speeds and may lose their stability in different manners at high speeds. In this study, the potential of active steering control of the semitrailer on manoeuvrability and stability of tractor-semitrailer combinations is investigated. A linear bicycle model and a nonlinear version are used for controller design and vehicle dynamic simulation in MATLAB environment. The Linear Quadratic Regulator optimal state feedback control is used to minimise the tracking error at low-speed, and regulate Rearward Amplification ratio and roll at high-speed. Quantum Particle Swarm Optimisation is used for optimising the weighting factors. Three different control algorithms are introduced and it is demonstrated through simulations that the vehicle with the proposed steering control exhibits desirable improvements compared to the baseline vehicle.

scholarly journals Nonlinear multiple-input-multiple-output adaptive backstepping control of underwater glider systems

2016 ◽  
Vol 13 (6) ◽  
pp. 172988141666948 ◽  
Author(s):  
Junjun Cao ◽  
Junliang Cao ◽  
Zheng Zeng ◽  
Lian Lian
Keyword(s):  
Tracking Error ◽  
Multiple Input Multiple Output ◽  
Lyapunov Stability Theory ◽  
Oscillatory Behavior ◽  
Backstepping Control ◽  
The State ◽  
Underwater Glider ◽  
Adaptive Backstepping ◽  
Linear Quadratic ◽  
Adaptive Backstepping Control

In this article, an adaptive backstepping control is proposed for multi-input and multi-output nonlinear underwater glider systems. The developed method is established on the basis of the state-space equations, which are simplified from the full glider dynamics through reasonable assumptions. The roll angle, pitch angle, and velocity of the vehicle are considered as control objects, a Lyapunov function consisting of the tracking error of the state vectors is established. According to Lyapunov stability theory, the adaptive control laws are derived to ensure the tracking errors asymptotically converge to zero. The proposed nonlinear MIMO adaptive backstepping control (ABC) scheme is tested to control an underwater glider in saw-tooth motion, spiral motion, and multimode motion. The linear quadratic regular (LQR) control scheme is described and evaluated with the ABC for the motion control problems. The results demonstrate that both control strategies provide similar levels of robustness while using the proposed ABC scheme leads to the more smooth control efforts with less oscillatory behavior.

Robust H2 Output Feedback Controller Design for Damping Power System Oscillations

2017 ◽  
Vol 6 (10) ◽  
pp. 8
Author(s):  
Kho Hie Kwee ◽  
Hardiansyah .
Keyword(s):  
Power System ◽  
Output Feedback ◽  
Controller Design ◽  
Sufficient Conditions ◽  
Feedback Controller ◽  
Linear Matrix ◽  
Parameter Uncertainties ◽  
Worst Case ◽  
Output Feedback Controller ◽  
Power System Oscillations

This paper addresses the design problem of robust H2 output feedback controller design for damping power system oscillations. Sufficient conditions for the existence of output feedback controllers with norm-bounded parameter uncertainties are given in terms of linear matrix inequalities (LMIs). Furthermore, a convex optimization problem with LMI constraints is formulated to design the output feedback controller which minimizes an upper bound on the worst-case H2 norm for a range of admissible plant perturbations. The technique is illustrated with applications to the design of stabilizer for a single-machine infinite-bus (SMIB) power system. The LMI based control ensures adequate damping for widely varying system operating.

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