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.

Anomalous Behavior of Merchant Ship Steering Systems

1970 ◽  
Vol 7 (02) ◽  
pp. 205-215 ◽  
Author(s):  
Robert Taggart
Keyword(s):  
High Speed ◽  
Mechanical Characteristics ◽  
Anomalous Behavior ◽  
Similar Response ◽  
Steering Control ◽  
Unstable Condition ◽  
Ship Steering ◽  
Merchant Ship ◽  
Automatic Steering ◽  
And Control

An unusual combination of circumstances occurring during an Atlantic crossing of a highspeed containership created a situation where the rudder, acting in response to automatic steering control demands, caused excessive ship rolling. Further investigation revealed the existence of an unstable condition due to a combination of asymmetrical hydrodynamic and mechanical characteristics and the interrelationship of ship motion and control actuation. Similar response has been noted on other high-speed vessels and is a cause for major concern in future containership operations. The elements involved in creating these conditions have been examined in detail and a plausible explanation has been evolved as to how they can combine to produce the observed results. With an understanding of the causes of this anomalous behavior it is possible to devise means for preventing its occurrence in future designs.

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.

Energy Losses Related to Automatic Steering of Ships in Waves—Part I: Losses Under Conventional Autopilot Control

1983 ◽  
Vol 105 (3) ◽  
pp. 318-324 ◽  
Author(s):  
R. E. Reid ◽  
B. C. Mears ◽  
D. E. Griffin
Keyword(s):  
Computer Simulation ◽  
Time Domain ◽  
Energy Losses ◽  
Simulation Studies ◽  
Steering Control ◽  
Ship Steering ◽  
Captive Model Tests ◽  
Automatic Steering ◽  
Computer Simulation Studies ◽  
Hydrodynamic Data

Results are presented relating to energy losses due to ship steering in waves. Propulsion losses related to yawing and rudder activity of ships during open-seas course-keeping are evaluated. Two representative tankers of 250,000 and 400,000 dwt, and an 880 ft (268 m) long containership are examined, using hydrodynamic data resulting from captive model tests. The approach presented involves time-domain computer simulation studies of the yaw-sway-surge-rudder coupled motions of the ships. Evaluation of losses due to both yawing of the uncontrolled ship and those resulting from yawing and rudder effects in the automatically steered case are made. On the basis of the results presented it is shown that under the action of waves yawing of a ship results in significant energy losses. It is also shown that a substantial increase in energy losses occurs under automatic steering control with commonly accepted autopilot specifications.

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 Active steering control based on preview theory for articulated heavy vehicles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0252098
Author(s):  
Jie Tian ◽  
Qingkang Zeng ◽  
Peng Wang ◽  
Xiaoqing Wang
Keyword(s):  
High Speed ◽  
Single Point ◽  
Path Tracking ◽  
Lateral Stability ◽  
Steering Control ◽  
Linear Quadratic ◽  
Low Speed ◽  
Active Steering ◽  
Simulation Results ◽  
Active Steering Control

This paper investigates the active steering control of the tractor and the trailer for the articulated heavy vehicle (AHV) to improve its high-speed lateral stability and low-speed path following. The four-degree-of-freedom (4-DOF) single track dynamic model of the AHV with a front-wheel steered trailer is established. Considering that the road information at the driver’s focus is the most clear and those away from the focus blurred, a new kind controller based on the fractional calculus, i.e., a focus preview controller is designed to provide the steering input for the tractor to make it travel along the desired path. In addition, the active steering controllers based on the linear quadratic regulator (LQR) and single-point preview controller respectively are also proposed for the trailer. However, the latter is designed on the basis of the articulation angle between the tractor and trailer, inspired by the idea of the driver’s single-point preview controller. Finally, the single lane change maneuver and 90o turn maneuver are carried out. And the simulation results show that compared with the single-point preview controller, the new kind preview controller for the tractor can have good high speed maneuvering stability and low speed path tracking ability by adjusting the fractional order of the controller. On this basis, three different AHVs with the same tractor are simulated and the simulation results show that the AHV whose trailer adopts the single-point preview controller has better high-speed lateral stability and low-speed path tracking than the AHV whose trailer adopts the LQR controller.

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.

scholarly journals OPTIMAL CONTROL OF AN ACTUATOR OF A ROBOTIC GEARBOX

2021 ◽  
Vol 1 (92) ◽  
pp. 72
Author(s):  
Alexander Gurko ◽  
Mykola Mykhalevych
Keyword(s):  
Optimal Control ◽  
Control System ◽  
High Speed ◽  
Performance Criterion ◽  
Optimal Controller ◽  
Mechanical Transmission ◽  
Linear Quadratic ◽  
Weighting Factors ◽  
Dc Motors ◽  
The Impact

Problem. Despite the vigorous development of electric vehicles, the task of facilitating the driver to handle with elements of mechanical transmission remains relevant. For this purpose, the automation of mechanical transmission units is performed. For instance, so-called robotic gearboxes are widespread. The principle of operation of such gearboxes is similar to mechanical ones, but special separate actuators carry out the selection and shifting into the desired gear. The design of a robotic gearbox was proposed at the Automobile Department of Kharkiv National Automobile and Highway University. At this gearbox, two DC motors are used as actuators. The efficiency of this gearbox largely depends on the efficiency of the DC motors control system, which should provide smooth but at the same time fast and accurate positioning of their shafts. In previous works, PID controllers were used to controlling the actuator of the gearbox. However, although the PID controller provides satisfactory quality of the control system, it is not an optimal controller. Goal. The goal of this paper is to develop an optimal controller for the actuators of the robotic gearbox mentioned above. Methodology. To meet this goal, it was proposed to use a linear-quadratic controller (LQR). The analysis of the impact on transient processes in the control system of the values of the weighting factors in the quadratic performance criterion is performed. Results. The LQR synthesized provides high speed of response (within of 0.5 s) at the desired gear selecting and more than two times less overshoot compared to the PID regulator. Originality. The regularities in the gearbox drive performance when changing the values of the weighting factors in the performance criterion have been established. An optimal control system for the robotic gearbox actuator has been developed. Practical value. The implementation of the designed controller will increase the efficiency of the gearbox under consideration.

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.

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