Marine Systems Simulator

The HyMarCS program is a 5-year research program coordinated at NTNU with participants from different universities, research centers and industry. This research program is dedicated to the analysis and design of fault-tolerant and multi-objective guidance and control systems for marine vessels. The aim of these designs is to increase safety and reliability in diefferent vessel operational conditions (VOC).

Announcements:

HyMarCS Workshop 16-17 Feb 2006, Oppdal, Norway

Program description

Vessel operational conditions: Marine systems perform complex operations or missions in ever changing operational conditions. The vessel operational condition (VOC) can be defined as a triplet of attributes:

Where

use-mode refers to the vessel current task, e.g., drilling, ocean passage, confined water passaje, ROV support.
environment refers to waves, current and wind, and water depth.
vessel condition refers to
- Speed
- Loading condition
- Stability (intact damagaed)
- available resources (power, communications, navigation system, actuators)
- Level of automation (amount of human interventions)

Each use-mode may call for the following services (guidance and control modes):

Station keeping,
Course keeping,
Manoeuvring control,
Motion damping,
Thruster assisted mooring,
Speed control.

These services can be further specifies as

Service ^k_j = <inputs_l, outputs_m, objectives_n, resources_p>

Where

inputs refers to the set of input (or consumed) variables available to provide the service.
outputs refers to the set of output (or generated) variables required by the service.
objectives refers to the objectives related to the control, guidance and monitoring systems.
resources refer to all those currently available to provide the desired service: power, number of actuators, level of automation ( Human intervention).

The sub-index j identifies the service and the super-index k identifies the version of the service. The same service can be provided under different versions depending on the input /output variables and resources available. Faults at different levels in the system affect the resources, inputs and putputs, while changes in the environmental conditions can affect the service objectives.

Figure 1 presents a diagram representative of the changes in VOC that a vessel can go through during particular missions via two examples.

Hybrid systems and hybrid control: Due to the changes in VOC that a vessel often encounters during a given mission, the design of guidance, control, and monitoring systems must be able to adjust to the various VOC. With the current availability of models, theory and technology, this can be achieved by design of different controllers using different models, which are characteristic of particular VOCs and perform the necessary changes as a mission evolves through various VOCs. This design methodology falls within the so-called hybrid system modeling and hybrid control, in which the system to be controlled and/or the control system are described by a mix of two types of components:

Continuous type (with signals evolving in dense sets)
Discrete type (with signals evolving on discrete sets)

Hybrid control is similar to adaptive control in the sense it allows changes in the controller. However, it allows changes in the control structure and large changes in parameters. This is necessary for the design of marine systems operating across different VOCs.

Hybrid control design can also cover the design of fault-tolerant control schemes which aim at the graceful degradation of automated systems in the case of faults, so that it remains available satisfying its designated goal.

Research areas considered

The following areas will be considered within the scope of the program:

Modelling of marine vessels in changing Vessel Operational Conditions (VOC)
System identification to cope with changing VOC
Adaptive guidance and control in changing VOC
Control of marine vessels at plant ant actuator level
Methods for control of switched and hybrid systems
Fault-tolerant, nonlinear and supervisory control
Reliability and risk analysis of marine operations in changing VOC
Human aspects of marine operations.

Program Objectives

The main objective of HyMarSC is to introduce hybrid control as a design methodology for marine control systems, to develop a “super system” capable of handling automatically the integration of different VOC.

This will be achieved by

Gaining insight into the design of control strategies for ships in different VOC.
Developing appropriate models for both high-fidelity simulations and control system design in different VOC.
Specifying appropriate control architectures to handle hybrid and fault tolerant marine control systems.
Addressing theoretical and implementation issues associated with the switching and supervisory control system design.
Developing fault detection and diagnosis techniques that target different marine operations, which can be reconfigurable according to risk analysis.
Designing new generation of hybrid fault-tolerant controllers for ships based on a tight integration of control theory and hydrodynamics and structural mechanics.
Ensuring the satisfaction of safety and reliability requirements for the control system operation.

Expected Outcomes

To develop design methodologies to address current industry problems.
To educate PhD candidates and researchers in the area of marine control systems.
To improve international collaboration between leading universities and research groups.
To promote collaboration between universities and industry.
To publish high-quality papers in international journals and conferences based on theoretical-experimental results.

Organization

Key Personnel and Responsibility

Person	Responsibility	Contact Details
A.J. Sorensen (CeSOS, NTNU-IVT)	Management/research	asgeir.sorensen@ntnu.no
T. Perez (CeSOS, NTNU-IVT)	Management/research	tristan.perez@ntnu.no
T. I. Fossen (CeSOS, NTNU-ITK)	Research	fossen@ieee.org
M. Blanke (DTU/NTNU)	Research	mb@oersted.dtu.dk
T.A. Johansen (CMinMC, NTNU-ITK)	Research	tor.arne.johansen@itk.ntnu.no
K.Y. Pettersen (CMinMC, NTNU-ITK)	Research	kristin.y.pettersen@itk.ntnu.no
T. Moan (CeSOS, NTNU-IVK)	Research	tormo@marin.ntnu.no

Key Personnel and specific research areas

Person	Tasks
A.J. Sorensen	Control structure/architecture, low level control, plant control, modelling, ride control.
T.Perez	Motion damping, constrained control, system identification
T. I. Fossen	Nonlinear control, maneuvering, hydrodynamics
M. Blanke	Fault-tolerant Control, motion damping
K. Y. Pettersen	Non-linear control, control of under-actuated systems
T.. A. Johansen	Optimization, hybrid control
T. Moan	Reliability and risk in operations
S.T. Quek (NUS)	Collaborator: Hybrid DP control and structures
Ge, Shuzhi Sam (NUS)	Collaborator: Intelligent control of vessels, underwater robots and structures

Editor: Tristan Perez Updated: 12-Jan-2006

Hybrid Marine Control Systems (HyMarCS)