ABDELLAOUI Ali - Automation on board ships Diapo

People’s Democratic Republic of AlgeriaMinistry of Higher Education and Scientific Research

University of Sciences and Technology of Oran – Mohamed Boudiaf

Mechanical Engineering FacultyMaritime Engineering Department

Option: Management of Naval Propulsion SystemsTheme:

Automation on board ships

Presented by:Mr ABDELLAOUI Ali

Tutor and adviser: Pr. MOKHTARI Abdellah

Presented on June 16th 2015

Automation on board Ships

1. Introduction

2. Historical Overview of Automation

3. Ship Automated Control System

4. Sensors on board Ship

5. Digital Control System (DCS)

6. Conclusion

Ship Automation

Sensors

1. Introduction

Automation or Automatic Control is the use of various control systems for operating equipment such as machinery and processes in factories. The biggest benefit of automation is that it saves labor, however, it is also used to save energy and materials and to improve quality, accuracy and precision.

In the maritime industry, the human element of the human-machine system is becoming an endangered species, partly because of the drive towards smaller crew numbers, but largely due to spreading of automation use.

The Centrifugal governor, which dates to the last quarter of the 18th century, was used to adjust the gap between millstones. The centrifugal governor was also used in the automatic flour mill developed by Oliver Evans in 1785, making it the first completely automated industrial process.


2.1. The Centrifugal Governor


2.1. The Centrifugal Governor


2.2. The Chip Log

This method was known as a Dutchman’s log.

The number of knots that had gone over the ship’s stern represent ship’s speed.


2.3. The Astrolabe

Mariner’s Astrolabe was used to determine the latitude of a ship at sea by measuring the noon altitude of the sun or the meridian altitude of a star in which the declination is known.


2.4. Water level float control

This regulator is the first historical feedback system.

The float detects the water level and controls the valve that covers the water inlet in the Tank.

3. Ship Automated Control System – Ship Automation

DEFINITION:A control system is an interconnection of components forming a system configuration that will provide a desired system response. The input–output relationship represents the cause and effect relationship of the process. A basic instrument system consists of three elements:

• Sensors• Signal processor• Receiver or output device


An open-loop control system utilizes a controller or control actuator to obtain the desired response. An open-loop system is a system without feedback.


a closed-loop control system utilizes an additional measure of the actual output to compare the actual

output with the desired output response.

This system permits the Level gauging, Control of cargo pumps, Valve control, Ballast and ballast pump control, Heeling control, Remote monitoring of temperature, pressure, and flow.


Cargo control system Signal control

unitComputer unit

Tank level sensors

Cargo temperature sensor

Various other

sensors

3. Ship Automated Control System – Sensors

The devices used to transform one kind of energy to another is called

Transducer,

When the transducer converts a physical

quantity into electrical current it is called SENSOR

When the transducer converts an electrical current into physical quantity it is called

ACTUATOR

Sensors can be classified according to several

categories:


Passive and active sensors Analogue and digital sensors Wired or Wireless sensors

It can be classified according to several categories:


Passive and active sensors Analogue and digital sensors Wired or Wireless sensors

Passive sensor: Requires an external source of powerActive sensor: The output power is almost entirely provided by the measured signal.

Digital sensor: The signal produced or reflected by the sensor is binary.Analogue sensor: The signal produced by the sensor is continuous and proportional to the measured parameter.

Wired sensor: Needs to be connected via electric cables to the control unit.

Wireless sensor: It is connected via wireless network to the control unit.


Level sensorsTemperature sensors


Temperature sensorsPressure sensors

4. Sensors on board Ships

Bridge control

installationDraught

measurement

Pressure sensors


Pressure sensors: Silicone type

This type of sensor work by the resistance principle, the silicon chip flexes as the pressure changes, the amount of silicon chip flexes determine the output voltage signal. As the measured pressure rises, the voltage signal increases.

Voltage signal curve.


Bourdon tubes are made of spring-like metal alloys bent into a circular shape.

Most pressure gauges use a bourdon tube as their pressure-sensing element.

Pressure sensors: Bourdon tube type Tank monitoring system:


The sensor emits a microwave pulse towards the process material. This pulse is reflected by the surface of the material and detected by the same sensor which now acts as a receiver.

Level measurement: Radar level sensor


Level measurement: Pressure based level sensors


By measuring the pressure at the bottom, or in the tank wall in a known height, we can determine the level.

This system is pressure based, pressure sensors are placed in the ship’s hull, the pressure value varies proportionally to the water level change, so the draught is measured.

Pressure sensor

Pressure sensor

Level measurement: Draught measuring system



Flow meters – Meshing rotor flow meter

The Meshing rotor type consists of two rotors with lobes. When fluid is forced in, the rotors turn and operate the indicating system.


Flow meters – Vortex flow meter

The function of vortex flow meters is based on the principle of the Karman vortex street. The measuring tube contains a bluff body, behind which vortex shedding occurs.

The number of vortices passing through the sensor (pressure sensor) determine the flow rate.

Flow direction

Engine pressure sensor – Piezoelectric type

The word piezoelectricity means electricity resulting from pressure.

Piezoelectric pressure sensor generates certain amount of electricity which is proportional to the value of the applied pressure.

It is used to determine pressure inside cylinders.


Engine pressure sensor – Capacitance type

It works by capacitance, it contains two metallic discs, when the pressure acts, it causes the change in distance between the two discs, as the gap changes, the capacitance also changes.


Thermistors are the most common used sensor to measure temperature of engine’s cooling liquid, lubricating oil and the intake manifold.

Engine Temperature sensor – Thermistor type

The resistance of thermistors is inversely proportional to temperature, as temperature increases, resistance decreases.


A Hall effect sensor is a transducer that varies its output voltage in response to a magnetic field.

Engine Speed sensor – Hall effect type



Definition:A Digital Control System (DCS) is a modern control system for a process or plant, wherein controlled elements are shown and can be adjusted via Human Machine Interface (HMI).

This system shows via several control panels mimic diagrams for the controlled installations, which makes the control much easier.

DCSs are the modern type of the “Automatic Computer Controlled Systems” family, in which we can change functioning parameters only by touching the digital interface.


On a ship, how do we control process using

DCS?


Introduction of the Engine Room Simulator software:Virtual Engine Room 4.8 is a PC-based full mission engine room simulator, It has all consoles, lamps, switches, levers, pushbuttons and analogue gauges and digitized sounds required. The mimic diagrams are similar to those found in real engine room control system interfaces.

Active control mode is possible.

By mean of a digital interface, which includes diagrams of all process elements, with active

control.

A engine room simulator software is used to show the method.












6. Conclusion

This simple study leads us to better understanding of the automation system, mainly the controlling systems

concerning ships. It shows the importance of automation, its benefits and the way it works.

Next few years, all the processes will be fully automated, wireless sensors and wireless control networks will be

involved as the main technology.

Thank you for your

attention

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ABDELLAOUI Ali - Automation on board ships Diapo