Fish Robot

Fish Robot Project
Principles of the Swimming Fish Robot
We can say that fish swim with pushing water away behind them, though fish swim by various methods. As the well-known categories for the swimming fish, a zoologist, C.M. Breder classified into the following three general categories based on length of a tail fin and strength of its oscillation (see the figure to the right).
(a) Anguilliform: Propulsion by a muscle wave in the body of the animal which progresses from head to tail like the Eel.(b) Carangiform: Oscillating a tail fin and a tail peduncle like the Salmon, Trout, Tuna and Swordfish.(c) Ostraciiform: Oscillating only a tail fin without moving the body like the Boxfish.

http://www.nmri.go.jp/eng/khirata/fish/general/principle/index_e.html


Fish Robot (Analysis And Mathematical Modeling of Thunniform Motion)
This research, Institute of Field Robot (FIBO) use the yellow-fin prototype tuna to build the robot because of its movement ability in high speed for a long time, thunniform mode, which make us believe that its movement will be the most efficient locomotion mode than other aquatic mammals. Additional, the body profile is both symmetrical in horizontal and vertical plane, which is helpful for finding out the equation of motion.

http://fibo.kmutt.ac.th/eng/index.php?option=com_content&task=view&id=265

Model Fish Robot, PPF-06i
It was confirmed that the PPF-06i swims with swimming speed of about 0.1 m/s using the micro-computer. Also, it was confirmed that the PPF-06i turns with turning diameter of about 1 m, when the tail swings to one side during the turning. I think that one of the above purposes, (i) Swimming of the fish robot using R/C servomotors controled by a micro-computer, was achieved approximately.On the other side, another of the purposes, (ii) Simple control by sensors, has not been achieved.

http://www.nmri.go.jp/eng/khirata/fish/model/ppf06i/ppf06ie.htm

Design Concept of the PPF-08iThe model fish robot named PPF-08i has been developed after considering the previous model fish robots, PPF-06i and PPF-07i. The design concept and purposes are as follows:(1) Simple structure(2) Small size(3) High turning performance (small turning diameter),(4) Controlled by a microcomputer,(5) A basic model of the group robots.

http://www.nmri.go.jp/eng/khirata/fish/model/ppf08i/ppf08ie.htm

Prototype Fish Robot, PF-600

The figure to the right shows the structure of the PF-600. A battery, R/C receiver and two servos are located in the body. Two rods connect link mechanisms in the two tail peduncles (forward and tail peduncles), and finally the tail fin through rod seals. For sliding rod seals, slide bearings are used. Other parts that do need to move are sealed with "O" rings.http://www.nmri.go.jp/eng/khirata/fish/experiment/pf600/pf600e.htm


Fish Robot Research
On the Design of an Autonomous Robot FishAbstract—A fish-like propulsion system seems to be an
interesting and efficient alternative to propellers in small
underwater vehicles. This paper presents the early design
stages of a small autonomous robotic vehicle driven by an
oscillating foil. It describes the preliminary dimensioning of
the vehicle and the selection and sizing of the necessary
actuators according to the project’s objectives and constraints.
Finally there is a description of the control system
implementation for the tail’s motion.

Fish swimming is classified as carangiform, anguiliform,
thunninform and ostraciform, depending on the percentage
of their body that contributes in thrust production through
undulatory motions. According to this observation, there
are three alternative ways to design a robot fish, see Fig.

http://nereus.mech.ntua.gr/pdf_ps/med03.pdf

A simplified propulsive model of bio-mimetic robot fish
and its realizationSUMMARY
This paper presents a simplified kinematics propulsive model
for carangiform propulsion. The carangiform motion is
modeled as a serial N-joint oscillating mechanism that is
composed of two basic components: the streamlined fish
body represented by a planar spline curve and its lunate
caudal tail by an oscillating foil. The speed of fish’s straight
swimming is adjusted by modulating the joint’s oscillatory
frequency, and its orientation is tuned by different joint’s
deflections. The experimental results showed that the proposed
simplified propulsive model could be a viable candidate
for application in aquatic swimming vehicles.

Fig. 1. Physical model of fish swimming.http://journals.cambridge.org/download.php?file=%2FROB%2FROB23_01%2FS0263574704000426a.pdf&code=b84242209ac7a0d01e3a1a9fe14560df


Body Construction of Fish Robot in Order
to Gain Optimal Thrust Speed
Abstract
In fish robot, hydrodynamic shape of its body determines
the ability of the robot to swim. However, sometimes the
swimming gait depends not only on the body, but also on
the frequency of tail undulation and body angle when it
attempts to achieve fast swimming. Thrust speed becomes
the main objective in this research. Some variables which
are suspected as important variables influencing the thrust
speed were observed such as body shape, fin, frequency
of tail, and acceleration of tail. Results of investigation
show that there are some significant dependency among
thrust speed, frequency of tail undulation and body shape.
In some conditions it was found that there was some
optimal condition for all parameters which pace the fish
robot towards fastest thrust speed.

http://www.geocities.com/yeffryhp/ICIUS_2007.pdf
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Fish Robot Vedio
Fish robot Vedio


Robot fish – shark vedio


Squid Robot Vedio



Robot fish vedio



AQUAROID ARTIFICIAL ROBOT-FISH VEDIO


Robot fish synchronise into schools vedio

Fish Robot

InfraRed Distance Sensor Project

Test Setup for the Sharp GP2D12
Distance Measurement Detector

I use the Sharp GP2D12 non-contact infrared distance sensor
for determining the level of salt on the Water Softener Monitor
project. To test the Sharp sensor and to determine the
voltages at particular distances, I created a test apparatus
out of a level and some machined plastic parts. This test
setup is compatible with the whole family of Sharp distance
sensors, which are capable of different measurement distances
and different types of outputs

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Design and development of a new sensor
system for assistive powered wheelchairs

Abstract. Many disabled people experience considerable
difficulties when driving a powered wheelchair. Disabled people
who are not able to drive a powered wheelchair are seriously
limited in their mobility. Several robotic assistive wheelchairs
have been devised in the past. These wheelchairs are equipped
with range sensors, which detect obstacles and measure the
distance to the closest object. The authors are involved in this
kind of projects but, although many sensors exist commercially,
they never found satisfactory range sensors for wheelchair
applications. After identifying these sensor requirements, this
paper presents the design of an optical ranging system, more in
particular a lidar (Light Detection and Ranging) scanner for
wheelchair applications. Test results are reported to show that
this scanner meets the identified requirements.

Sensor design
An approach that is now feasible at a modest price
tag, is using a lidar scanner (Light Detection And
Ranging). Various systems already exist on the market
that use light instead of the microwaves of the well
known radar. A lot of research has been done on range
finders, anti-collision systems for the car industry and
pollution surveillance systems. Most of these systems
use large aperture optical telescopes, powerful lasers
and ultra fast electronic devices for the processing of
the data to determinate the time of flight of the emitted
and reflected light. They have a range of several hundred
metres up to a few kilometres. This performance
is much too high and most of these systems are rather
bulky and very expensive and are not always eye-safe.
All these factors exclude their use on a wheelchair.
The range of the obstacle detection system is from zero
up to 4 m. The determination of the time-of-flight in
this range, calls for ultra fast electronics (660 ps time
resolution for a spatial resolution of 10 cm) and puts
a high demand on the switching characteristics of the
opto-electronic components.
In order to keep the complexity of the system, the demand
on the opto-electronic components and the price
tag low, it is proposed to substitute the direct timeof-
flight measurement by the measurement of a phase
shift. The light from an infra-red laser diode is amplitude
modulated with a signal of 5–20 MHz, depending
on intended range or resolution. The difference in
phase between the signals from the transmitted and re-
flected light is directly proportional to the distance. The
advantages of this method are the much lower switch
frequency, the lower data processing speed and the use
of less exotic components. The disadvantages are the
longer time it takes to get the measurement (some microseconds),
compared to the time-of-flight measurement
(some nanoseconds). This is only important in
3D scanning systems where data throughput must be
very high. If the signal-to-noise ratio does not enable
a stable measurement, the bandwidth of the processing
circuit must be further reduced, increasing processing
time. This is not necessarily a drawback in wheelchair
applications because the sample rate can still be suffi-
cient high. Scanning in a horizontal plane can be performed
by a rotating mirror, reflecting transmitted and
received beams, or by rotating optics. The scanning
rate of the lidar amounts to 5 rev/s.
Different modules for the lidar scanner have been
developed:

– aspheric lens design for optical transmitter and
receiver,
– laser diode output stage (transmitter),
– PIN diode preamplifier,
– limiter and phase measurement (distance measuring),
– microprocessor and interface,
– scanning system.

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