about rudder

1. Rudder Actuation
System for an
Autonomous System
PRESENTED BY:
T.NAGARAJU,
14341D6811,
VLSI & ESD ,
ECE DEPT.
Under The guidance Of
Ch. Kalyan Chakravarthi,
Assistant professor,
Department Of ECE.

2. Abstract-
 This paper describes design, test
and evaluate of a Rudder actuation system for an
autonomous vehicle. Autonomous vehicle
consists of GPS system interfaced with rudder
actuation system which is used to guide the ship
towards destination without human interface. This
system is used to replace the existing hydraulic
actuators which are currently used to control the
fin's position. Rudder actuation system uses 8051
Microcontroller to control the fin’s position which
gives more accuracy in position control when
compared with Hydraulic actuators.
Subsequently, the performance of the whole
Rudder actuation system and especially the
behavior of the controller have been tested with
different handling maneuvers.

3. Introduction
 A Rudder is a device used to steer a ship, boat, submarine,
hovercraft or other conveyance that moves through water .
 In small craft the rudder is operated manually by a handle
termed a tiller or helm.
 There is a strong desire to remove humans from this task.
 In larger ships, the rudder is controlled by hydraulic
actuators.
Hydraulic actuators have following disadvantages:
 low reliability, high pressure seals which may leak, High
consumables like oil/cleaning/flushing fluid are required,
requires more weight and space, requires more power
consumption. So there is a need to over come these
drawbacks by using some control mechanism.

4. METHODOLOGY
 Block diagram of the controller board is
shown in figure .
 The block diagram consists of following
blocks: Microcontroller8051, keypad, LCD,
GPS, Driver and DC motor.
 Microcontroller is the main block of the
system. User feeds the source and target
information through keypad to the
microcontroller. Through GPS,
microcontroller extracts current location of
the ship.
 Using source, destination, and current
values, the controller calculates the angle
to which the rudder has to be rotated. This
angle is feed to the driver which drives the
DC motor.

5. Keypad and LCD:
Keypad: 4X4 Keypad is used to provide source and target
information to the microcontroller.
This keypad is interfaced to port 0 of microcontroller through
RS232 cable.
LCD: LM016L Hitachi Display is connected to the
microcontroller using a data cable through port 1.
LCD receives longitude and latitude information through GPS
and displays the same on LCD screen.
 Pins 5, 6, 7 of port 1 are used for enable, write and read
operation.

6. GPS interface:
In this work, the ProGin SR-95 GPS system is
used. This GPS system is interfaced to port 3 of microcontroller
through RS232 cable.
The GPS system gives the current position information about the
ship to Microcontroller and the same is displayed on LCD.
GPS gives the data in NMEA (National Marine Electronics
Association) format
The GPS module continuously transmits serial data (RS232
protocol) in the form of sentences according to NMEA
Standards.

7.  Triangulation is the process of determining the
location of a point by measuring angles to it from
known points. Triangulation Method
Overview can be shown as:
Figure 1: Triangulation Method Overview

8. Figure 2 : Angle Calculation.
calculation of the angle
 A, B, C are the source, current and
destination positions and a, b, c are
the distance between B and C, A
and C, A and B. The formula used by
the Microcontroller to calculate error
is as given in the equations:
β=cos −1
⎛⎜⎜⎝a2
+2cac
2
−b
2
⎞⎟⎟⎠ ………………. (2)
= −⎛180⎞β
error _angle 180 ⎜⎟ ………. (3)
⎝π ⎠

9. DRIVER and DC motor:
 The DRIVER which drives the motor is interfaced
with the microcontroller as shown in the figure 1.
 Port line 2, 6, 7 of port 2 is used as anticlockwise,
enable, clockwise respectively.
Data is sent to the driver which defines the turn
angle of the ship for particular generated error angle.

10.  The rudder which controls the movement of ship is
attached to the DC geared motor. When there is any
deviation from the desired path microcontroller
generates an error signal.
 This error signal is given to the Geared DC Motor
through the driver. Depending on the error angle
generated, motor rotates through a specified number
of degrees to correct the error.
 The above discussed procedure is to calculate the
error angle at particular instant of time.
 The concept is repeated again and again until the
ship has reached the specified target point.

11. RESULTS
Error angle is calculated by using Mathlab. The same
is verified using Microcontroller and DC motor.
Table 1: Mathlab Calculated Test Results.

12. Table 2: System Test Results
 Also, 0.312 ms is the measured reaction time of
the system. This is the minimum time required to
drive the motor after calculating the error angle,
by the microcontroller.

13. The snap shot of the overall system is shown in
figure 3.
Figure 3:
Snapshot of overall system.

14. CONCLUSION:
In this work, Microcontroller 8051 is used for controlling the
rudder the same can be replaced with high end
Microcontrollers.
The GPS ProGin SR-95 gives accuracy of 2meters, whereas,
manufacturing accuracies of the order of 0.001 meter or
better are needed.
There is a strong desire to remove humans from this task.
In this work a detailed analysis and design of GPS
controlled navigation is carried out to generate accurate
rudder angle in minimum time.
So if we go for high end GPS we can still improve our
system performance. In Geared DC motor, the error in
rotation is of 2o and there is a problem of inertia also. These
errors can be reduces by using advanced motors like servo
motors.

15. REFERENCE:
1. 2009 International Conference on Advances in Computing,
Control, and Telecommunication Technologies. Rudder
Actuation System for an Autonomous System. Research scholar, R.
V. Center for Cognitive Technologies, Bangalore, India .Email ID:
nkotrick@gmail.com.
1 .Fossen, T. I., “Guidance and Control of Ocean Vehicles”.
John Wiley & Sons Ltd. 1994
2. K. D. Do, Z. P. Jiang, and J. Pan, “Under actuated ship global
tracking under relaxed conditions”, IEEE Trans. Autom. Control, vol.
47, no. 12,pp1529-1536, dec2009
3. Measurement by the use of triangles
http://en.wikipedia.org/wiki/Triangulation
4. T.I. Fossen, “Marine Control Systems”, Marine Cybernetics AS,
2002
5. Than Htike, Tin That Ngwe and Yin Mon Myint, “Practical
Approach to Rudder Control System for UAV using Low Cost MEMS
Sensors”, 2008

16. THANK YOU