A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part II: Controller Design

1982 ◽  
Vol 104 (1) ◽  
pp. 9-18 ◽  
Author(s):  
R. E. Reid ◽  
J. W. Moore
Keyword(s):  
High Speed ◽  
Linear Models ◽  
Controller Design ◽  
Weather Conditions ◽  
Adaptive Controller ◽  
Frequency Domain Analysis ◽  
Domain Modeling ◽  
Steering Control ◽  
The Face ◽  
Time Domain Modeling

An approach to design of steering controls for high-speed containerships to minimize propulsion losses is described. It involves time domain modeling and simulation, frequency domain analysis, and control structure investigation. A design process based on the use of linear modern and classical control techniques with locally linear models to minimize propulsion losses at important design conditions on the ship’s operating envelope is discussed. An adaptive controller to provide envelope-wide control in the face of changing environmental conditions and ship characteristics is described. Results from simulations and full-scale sea tests are summarized. On the basis of these preliminary results it appears that the adaptive controller works well under different speed and weather conditions and offers the potential for a reduction in propulsion losses over an existing PID autopilot.

A Steering Control System to Minimize Propulsion Losses of High-Speed Containerships—Part I: System Dynamics

1982 ◽  
Vol 104 (1) ◽  
pp. 1-8 ◽  
Author(s):  
R. E. Reid ◽  
J. W. Moore
Keyword(s):  
Control System ◽  
Modeling And Simulation ◽  
Time Domain ◽  
High Speed ◽  
Steering System ◽  
Performance Criteria ◽  
Domain Modeling ◽  
Added Resistance ◽  
Steering Control ◽  
Time Domain Modeling

The problem of steering control of high-speed containerships to minimize propulsion losses is addressed. The approach involves time domain modeling and simulation. A dynamic model of a containership and steering system in a seaway is constructed. Performance criteria for added resistance associated with yawing and steering are discussed. Losses resulting from yawing of the uncontrolled ship in heavy weather are shown by simulation to be significant. The results presented form a basis for design of a controller to minimize steering related losses.

Feedforward Tracking Controller Design Based on the Identification of Low Frequency Dynamics

1993 ◽  
Vol 115 (3) ◽  
pp. 348-356 ◽  
Author(s):  
E. D. Tung ◽  
M. Tomizuka
Keyword(s):  
High Speed ◽  
Linear Models ◽  
Controller Design ◽  
Phase Error ◽  
Low Frequency ◽  
Reference Trajectory ◽  
Accurate Identification ◽  
Tracking Controller ◽  
Feed Drive System ◽  
Zero Phase

Several methodologies are proposed for identifying the dynamics of a machine tool feed drive system in the low frequency region. An accurate identification is necessary for the design of a feedforward tracking controller, which achieves unity gain and zero phase shift for the overall system in the relevant frequency band. In machine tools and other mechanical systems, the spectrum of the reference trajectory is composed of low frequency signals. Standard least squares fits are shown to heavily penalize high frequency misfit. Linear models described by the output-error (OE) and Autoregressive Moving Average with eXogenous Input (ARMAX) models display better closeness-of-fit properties at low frequency. Based on the identification, a feedforward compensator is designed using the Zero Phase Error Tracking Controller (ZPETC). The feedforward compensator is experimentally shown to achieve near-perfect tracking and contouring of high-speed trajectories on a machining center X-Y bed.

scholarly journals Discrete Time Domain Modeling and Control of a Grid-Connected Four-Wire Split-Link Converter

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 506
Author(s):  
Jeroen D. M. De Kooning ◽  
Dimitar Bozalakov ◽  
Lieven Vandevelde
Keyword(s):  
Discrete Time ◽  
Time Domain ◽  
Controller Design ◽  
Domain Model ◽  
Domain Modeling ◽  
Modeling And Control ◽  
Current Harmonics ◽  
Voltage Unbalance ◽  
Zero Sequence ◽  
Time Domain Modeling

Distributed generation (DG) allows the production of renewable energy where it is consumed, avoiding transport losses. It is envisioned that future DG units will become more intelligent, not just injecting power into the grid but also actively improving the power quality by means of active power filtering techniques. In this manner, voltage and current harmonics, voltage unbalance or over-voltages can be mitigated. To achieve such a smart DG unit, an appropriate multi-functional converter topology is required, with full control over the currents exchanged with the grid, including the neutral-wire current. For this purpose, this article studies the three-phase four-wire split-link converter. A known problem of the split-link converter is voltage unbalance of the bus capacitors. This mid-point can be balanced either by injecting additional zero-sequence currents into the grid, which return through the neutral wire, or by injecting a compensating current into the mid-point with an additional half-bridge chopper. For both methods, this article presents a discrete time domain model to allow controller design and implementation in digital control. Both techniques are validated and compared by means of simulation results and experiments on a test setup.

Independent Torque Control of an Independent-Wheel-Drive Electric Vehicle

2014 ◽  
Vol 663 ◽  
pp. 493-497
Author(s):  
M.H.M. Ariff ◽  
Hairi Zamzuri ◽  
N.R.N. Idris ◽  
Saiful Amri Mazlan ◽  
M.A.M. Nordin
Keyword(s):  
Electric Vehicle ◽  
High Speed ◽  
Controller Design ◽  
Torque Control ◽  
Lateral Acceleration ◽  
Steering Control ◽  
Vehicle Handling ◽  
Direct Yaw Moment Control ◽  
Wheel Drive ◽  
Yaw Moment Control

This paper focuses on designing a controller to enhance the traction and handling of an Independent-Wheel-Drive Electric Vehicle (IWD-EV). It presents a traction torque distribution controller for an IWD-EV in order to maintain vehicle handling and stability during critical maneuvers. The proposed controller is based on the Direct Yaw-moment Control (DYC) and Active Front Steering control (AFS) which intended to increase the handling and stability of the vehicle respectively by applying the yaw rate and the lateral acceleration as the control variables. The performance of the controller is evaluated by numerical simulations of two standard high speed maneuvers which are the double lane change (DLC) and J-Curve. The proposed scheme presents a new controller design for IWD-EV which can effectively improved the vehicle handling and stability.

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