Comparison of Optimal Linear Regulators Applied to Minimization of Steering Losses of a Containership in a Seaway Using Frequency Domain Representations

1982 ◽  
Vol 104 (3) ◽  
pp. 229-237 ◽  
Author(s):  
R. E. Reid ◽  
P. F. Parent
Keyword(s):  
Frequency Domain ◽  
High Speed ◽  
Performance Criteria ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Linear Regulator ◽  
Optimal Linear ◽  
Nonlinear Force ◽  
Linear Regulators ◽  
Derivatives Of

Linear Quadratic Gaussian (LQG) techniques are applied to the design of a steering controller for minimization of propulsion losses due to steering of a high-speed containership in a seaway. Alternate performance criteria are used deriving from the evaluation of the nonlinear force derivatives of the surge equation related to steering. The sensitivities of the various resulting LQG controllers to the seaway environment are compared using frequency domain representations of the seaway disturbances which are shown to be far from white Gaussian noise. The implications for optimal linear regulator design in this environment are discussed on the basis of the results presented.

Approximate solution to optimal linear quadratic Gaussian control over non-acknowledgment networks

2020 ◽  
Vol 357 (4) ◽  
pp. 2049-2066
Author(s):  
Hong Lin ◽  
Mei Liu ◽  
Huaicheng Yan ◽  
Jinliang Liu ◽  
Shan Lu
Keyword(s):  
Approximate Solution ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Optimal Linear

Energy Losses Related to Automatic Steering of Ships in Waves—Part II: Performance of Controllers Designed to a New Criterion

1983 ◽  
Vol 105 (3) ◽  
pp. 325-332 ◽  
Author(s):  
R. E. Reid ◽  
B. C. Mears ◽  
D. E. Griffin
Keyword(s):  
High Speed ◽  
Load Condition ◽  
Performance Criterion ◽  
Sensitivity Analyses ◽  
Energy Losses ◽  
Steering Control ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Automatic Steering ◽  
New Criterion

Minimization of energy losses associated with the steering control of modern ship types is discussed on the basis of frequency-domain sensitivity analyses and time-domain simulation studies. A high-speed containership and large tankers in the full-load condition are analyzed. A new performance criterion for minimization of steering-related propulsion losses is presented, and controllers designed to it using linear quadratic Gaussian (LQG) techniques. In the case of the containership, the resulting controller is shown to have the potential to reduce the net losses related to steering below those of the uncontrolled ship through proper use of the rudder in some conditions. While this does not seem possible for the tankers, the results indicate that a controller designed to the new criterion results in lower losses than a controller based on a form of criterion to which new autopilots for tankers are presently being designed. The implications for both autopilot and steering gear servo-design based on these results are discussed.

Active Command-Steering Control of Tractor and Three Full Trailers for Tractor-Track Following

2006 ◽  
Author(s):  
Krishna Rangavajhula ◽  
H.-S. Jacob Tsao
Keyword(s):  
High Speed ◽  
Control Strategies ◽  
Linear Quadratic Regulator ◽  
Cost Effective ◽  
Steering Control ◽  
Linear Quadratic ◽  
Amplification Ratio ◽  
High Speeds ◽  
Lqr Controller ◽  
Optimal Linear

A key source of safety and infrastructure issues for operations of longer combination vehicles (LCVs) is off-tracking, which has been used to refer to the general phenomenon that the rear wheels of a truck do not follow the track of the front wheels and wander off the travel lane. In this paper, we examine the effectiveness of command-steering in reducing off-tracking during a 90-degree turn at low and high speeds in an articulated system with a tractor and three full trailers. In command steering, rear front axles of the trailers are steered proportionately to the articulation angle between the tractor and trailing units. We then consider several control strategies to minimize off-tracking and rearward amplification of this system. A minimum rearward amplification ratio (RWA), as a surrogate for minimum off tracking, has been used as the control criterion for medium to high speeds to arrive at an optimal Linear Quadratic Regulator (LQR) controller. As for low speeds, the maximum radial offset between the tractor and trailer 3 is minimized in the design of the controller. Robustness of the optimal controller with respect to tyre-parameter perturbations is then examined. Based on the simulation results, we find that, active command steering is very effective in reducing off tracking at low- as well as high-speed 90-degree turns. To achieve acceptable levels of RWA and off tracking, at least two of the three trailers must be actively command-steered. Among the three two-trailer-steering possibilities, actively steering trailers 1 and 2 is most cost-effective and results in the lowest RWA for medium- to high- speeds (at which RWA is important), and off-tracking is practically eliminated for all speed regimes considered.

scholarly journals Body Travel Performance Improvement of Space Vehicle Electromagnetic Suspension System using LQG and LQI Control Methods

2020 ◽  
Author(s):  
mustefa jibril ◽  
Messay Tadese ◽  
Eliyas Alemayehu
Keyword(s):  
High Speed ◽  
Space Vehicle ◽  
Suspension System ◽  
The Body ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Linear Quadratic Optimal Control ◽  
Electromagnetic Suspension ◽  
Road Profile ◽  
Quadratic Integral

Electromagnetic suspension system (EMS) is mostly used in the field of high-speed vehicle. In this paper, a space exploring vehicle quarter electromagnetic suspension system is modelled, designed and simulated using linear quadratic optimal control problem. Linear quadratic Gaussian and linear quadratic integral controllers are designed to improve the body travel of the vehicle using bump road profile. Comparison between the proposed controllers is done and a promising simulation result have been analyzed.

scholarly journals Optimal control for networked control systems with multiple delays and packet dropouts

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142091376
Author(s):  
Xiao Lu ◽  
Qiyan Zhang ◽  
Xiao Liang ◽  
Haixia Wang ◽  
Chunyang Sheng ◽  
...  
Keyword(s):  
Control Systems ◽  
Networked Control Systems ◽  
Networked Control ◽  
Multiple Delays ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Packet Dropouts ◽  
Optimal Linear ◽  
Gaussian System ◽  
Necessary And Sufficient

This article focuses on the problem of optimal linear quadratic Gaussian control for networked control systems with multiple delays and packet dropouts. The main contributions are twofold. Firstly, based on the introduced maximum principle for linear quadratic Gaussian system with multiple input delays and packet dropouts, a nonhomogeneous relationship between the state and costate is obtained, which is the key technical tool to solve the problem. Secondly, a necessary and sufficient condition for the optimal networked control problem is given in virtue of the coupled Riccati equations, and the explicit expression of the optimal controller is presented. Numerical examples are shown to illustrate the proposed algorithm.

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