Animatronics - A SEMINAR
1. Introduction.
Animatronics is “the
technology employing electronics to animate motorized puppets”. The animatronics system is based on the
“system reality”. The animatronics figures are mainly created for entertainment.
At the heart of any animatronics figure we will find the power system. Simply put,
the power system, this is responsible for making figure to move. The movement
can be done by various types of motors and actuators. The movements of various
parts in animatronics figure is controlled by electronic control system. This
electronic control system is treated as brain to control the movements of
animatronics figures. The commonly used methods are Hydraulic systems and
Pneumatic systems. These methods are used separately or in combination along
with other technologies to create animatronics figures. Hydraulic systems gives
higher accuracy, while Pneumatic systems are easier to design and operate.
Hydraulic systems have number of advantages over Pneumatic systems and are
generally superior in reproducing exact movements.
2. What is animatronics? What are they used for?
3. How are
Animatronics created?
The animatronics figure can be created by following methods,
- Creating paper designs:
The first step to
creating Animatronics is to sketch the initial idea and create a paper design.
Depending on the specifics of the project, different experts are brought in.
During the creation of Jurassic Park’s Spinosaurus, paleontologists advised on
the accuracy of the initial design. In the creation of “It’s a Small World”,
color stylist and designer Mary Blair was assigned the job of drawing the
children. These paper representations of the final animatronics figure tell
engineers and artists in each following step what the goal is for the end
creation.
Fig. An artist sketches the
Spinosaurus.
- Preparing Maquette:
After the paper design
has been finalized, the next step is to create a maquette, or miniature model
of the final design. This model is often made out of clay. It is especially
important to create a maquette when building very big animatronics because it
tests the feasibility of the paper design without wasting the time and
resources that would be needed to build a full-scale model. The maquette also
allows designers to add the 3-dimensional, surface detail that is difficult to
depict in sketches.
Fig: Maquette of the Spinosaurus
3. Build a Full-size
Sculpture:
The completed maquette
is used to build a full-sized sculpture of the final creature. While this used
to be done by hand, computer-aided manufacturing has automated the process. The
maquette is scanned with a series of very precise lasers and then the final
sculpture is milled out of foam. If the animatronics figure is very large, the
final sculpture is milled in pieces and then secured together with special
glue.
Fig. Full-size sculpture.
4. Molding and
Casting:
Next, the full-sized
sculpture is used to create a mold so that the body can be cast out of foam
rubber to create the skin. The skin is very important to the animatronics
character’s ability to function because the character must usually look
natural. Skin that is too thick and difficult to move would cause clumsy
movements.
Fig. Creating the mold.
5. Creature Creation:
The next step in
creating an animatronics figure involves the largest number of engineers. It is
building the various animatronics components which allow the animatronics
figure to evolve from “puppet” or “sculpture” to “animatronics”.
Fig. Creating head of T-Rex.
The “skeleton” of an
animatronics figure often resembles the skeletons of animals in the real world.
It gives the figure structure and holds the pieces together. An alternative to
the traditional inner skeleton is an outer-skeleton, like the exoskeleton of an
insect. The advantage to this model is more room inside the figure for other parts.
The mechanical parts
of the animatronics figure create the “muscles” that create movement of the
skeleton. Some animatronics (such as the characters of “It’s a Small World”)
have few moving parts, and therefore require fewer “muscles” which can be made
with basic mechanisms. Newer, more modern, animatronics figures, however,
involve complex systems of hydraulics or pneumatics. Hydraulics offer higher
accuracy, while pneumatics are easier to design and operate. Despite this
complexity, most of the mechanical parts in animatronics figures come from the
basic wedge, screw, lever, pulley, wheels, and gears, just like the early
automata. What has grown more sophisticated is how these mechanisms are
powered.
Fig. All hydraulic systems are installed and checked.
A “brain” is needed to
control the “muscles”, and so electronic control systems are created to operate
the animatronics figure. These systems are created by electrical engineers with
custom circuit boards. Some animatronics are manipulated through telemetry.
This allows a puppeteer to control the movement off-screen. For figures made to
repeat their movements many times at a theme park, their movements may be
programmed into the figure, so that the figure may operate on stage without
constant attention.
6. Putting it together:
Fig. The "skeleton" of the Spinosaurus.
Finally, the skeleton,
the mechanics, and the electronics are fitted together with the skin to
complete the animatronics figure. It is very important at this stage in the
design process to ensure there has been clear communication between the groups
responsible for different parts of the design process. The final finishing
touches, such as sculptural details are then added and the figure is put
through a series of final tests to ensure its dependability.
Fig. Painting the skin.
4. An Animatronic System Including Lifelike
Robotic Fish
It is well known that marine
creatures, such as fish, that swim using small power as well as at high speeds
(dolphin: 60 km/h, swordfish: 80 km/h) are superior in their position-keeping
characteristics. These characteristics as creatures have been of interest to
science for a long time, and much research has been conducted however, it is
rare to study these characteristics from the viewpoint of engineering. The
purpose of this research is a flexible oscillating fin control system which
could be used for the propulsion of marine vehicles by positively making most
of the characteristics of the flexible part. This method obtains a propulsion
force by oscillating fins equipped to vehicles on the analogy of the motion of
marine creatures. After the control system for a flexible oscillating fin
propulsion device and the oscillating fin driving device were designed and
manufactured, a cruising test was performed, first by a numerical simulation
and then with a model ship, and the fundamental performance has been grasped
and prospects of putting the devices to practical use have been obtained.
Robotic fish for amusement in aquariums, etc., have been developed as an
applied product.
Advantages of the oscillating fin
propulsion system have been found and products of application have been created
by the research.
4.1 BASIC OSCILLATING FIN
PROPULSION SYSTEM
In many cases, the kinetic
parameters of the oscillating fin cannot be directly detected in control of an
oscillating fin, and there are problems choosing and identifying parameters to
be used for control; a control system able to cope with such problems should be
architected.
In the research, to cope with the
above problems, a study on the application of neural network learning control
has been made using a model ship. The control algorithm is architected and the
control computer software has been mounted; the cruising test
was then conducted in a tank.
Fig. 1 shows the outline of the
test device for the oscillating fin propulsion system which has been developed
for the basic tank test. The neural network learning algorithm has been created
in the control device. It consists of a hierarchy network of three layers,
which are input, middle, and output layers. The Hess and Smith method has been
expanded to a non-stationary problem; furthermore, a model applying the method
of solving deformation of the wake vortex using the discrete vortex method has
been used, and the I/O variables and node numbers of the middle layer have been
determined by simulation.
From Fig. 1, the input signals
are formed to give the ship speed, the propulsion thrust, the learning signal,
and the output signal to give the vibrating frequency, phase angle, sway angle,
and yaw angle amplitudes. The node number of the middle layer was determined to
be four from the viewpoint of error energy function and simplification of the
system.
Fig. 1. Test device.
The two-phase control
oscillator, ac servo control amplifier, oscillating fin driving device, and
small-sized three-component force block gauge for fluid measurement were
designed and manufactured for this test. The oscillating fin driving device was
designed to be actuated linking sway direction motion with yaw direction motion
by mounting the yaw direction driving device on the sway direction driving
device.
The oscillating fin is
actuated by varying the amplitude, phase difference, and oscillating frequency
of sway and yaw motion. The oscillating fin consists of rigid and flexible
parts and the propulsion efficiency is improved by the flexibility of the
flexible part. The control computer consists of the neural network software and
the command generator. The command generator gives the command values of the
sway and yaw motion parameters of the oscillating fin. During the optimal
adjustment of motion parameters of the oscillating fin in the cruising test,
the neural network gets the learning data for back propagation. After the
network was constructed by back propagation, the oscillating fin is actuated
only by the neural network control and can self-cruise the vehicle.
4.2 EXPERIMENTAL
TEST OF OSCILLATING FIN
The flexible
oscillating fin propulsion device was produced experimentally, and only the
flexible oscillating fin propulsion device was independently tested before
loading it onto a model ship to examine the influence of the oscillating fin
shape and the flexible part on propulsion. The oscillating fin propulsion
device was loaded onto a model ship and the tank cruising tests were carried
out. The purpose of the tank tests was to grasp the propulsion characteristics
as a ship's actuator and self-cruising capability using only the neural
network.
Fig. 2 shows the
model ship with the oscillating fin propulsion device. During the cruising test
and by using the command generator, the cruising test learning data for the
neural network control is accumulated and the weights in the neural network are
determined by back propagation. The oscillating fin driving command signal is
given by the forward operation in the neural network, based on the target value
command, and then the model ship cruises. Also, transition of the thrust
force from a positive to a negative direction can be conducted smoothly only by
changing the phase angle of the sway and yaw motion. Therefore, it was found
that the transition of the thrust force from progress to reverse of the vehicle
can be conducted smoothly.
Moreover, propulsive
thrust and efficiency can be improved by using a flexible part of the
oscillating fin. The characteristics can be further improved by improving the
fin shape. The fish-tail-type fin is found to produce higher power compared
with the same area of a rectangular fin.
Fig. 2. Ship model with the oscillating fin
propulsion device.
Fig. 3 shows the principle of
the control system based on the technical research of the flexible oscillating
fin propulsion system. We can control the fish by regulating the amplitude,
frequency, and phase of the joints of the fin. Here, sway direction motion of
the oscillating fin can be achieved from the front joint angle of the fish and
yaw direction motion from the rear joint angle, respectively. Robotic fish have
been developed as an applied product of this system.
Fig. 3. Principle of control of robotic fish.
Batteries and a
buoyancy control device are built into the robotic fish, and three-dimensional
movement of the robotic fish is possible by remote control, using underwater
wireless information communication. It is generally thought that it is
difficult to transmit a signal underwater using the radio wave because the
attenuation of the radio wave underwater is large. However, it is actually
possible to transmit a signal underwater by using appropriate frequency and
modification. The computer wireless maneuvering control device and noncontact
submerged charging equipment as peripheral equipment have been developed and
continuous swimming can be conducted for hours. The controller was designed and
checked based on such hydrodynamic tests. Advanced control algorithms were also
applied to the robotic fish. Optimization of the fin shape was conducted by
nonlinear programming and genetic algorithm. Artificial intelligence (AI) and
chaos control were tried to simulate the real fish maneuvering. An example is
shown in Fig. 3.1. A very realistic and lifelike swimming method can be
realized by the flexible oscillating fin propulsion.
Fig. 3.1. Hydrodynamic tests of robotic fish.
4.4 ANIMATRONIC
SYSTEM
This research is
extremely important in technology for the new field of animatronics a
computer-controlled biomechanically engineered model, in this case, aquatic
creatures.
Animatronics technology is
rapidly gaining popularity throughout the world. It can be applied to create a
virtual aquarium not possible with computer graphics technology alone. We have
developed a method of enhancing event spaces that included animatronics for
modern-day fish, coelacanths, and Cambrian-world creatures able to swim under
their own electrical power. The concept of the system is shown in Fig. 4.
Spectators will be able to see the various lifelike fish robots swimming in the
tank. By using voice treatment technology and image recognition technology,
they will use variety variation functions where the fish answers to a voice or
the fish reads a number card.
Fig. 4. Concept of the animatronics system.
Fig.5. Block diagram of the control system.
It is very difficult to detect the motion of
a controlled oscillating fin directly; therefore, a control system needs to be
constructed so as to solve the problem of choosing and identifying the control
parameters. Furthermore, unless a mathematical model for the oscillating fin is
created, designing a model based on the control system becomes too difficult.
Various systems were
tried; ultimately, a combination of neural network, chaos, and other systems
has been applied to reproduce the motion of the fish naturally and
realistically with the robots. As for the control algorithm, software was made
and added to the control computer device; then a tank cruising test using
software was performed.
The block diagram of the control system is shown in Fig. 5. Via a
computer, supersonic sensors, controllers, and the oscillating fin generate,
adjust, and control the motion of the robotic fish. The control computer
consists of the control software and a command generator, which produces sway
and yaw motion parameters for the oscillating fin.
4.5 EVALUATING REALISM:
This animatronics system is based on
the “system reality” model whereby spectators take pleasure in watching the
robotic fish swimming in the tank. The premise is that reality appeals to human
sensitivity. The spectators compare the known image in their brain with the
robotic image before them and determine the level of realism (and by extension
the level of pleasure). However, if spectators have not seen real fish
swimming, they cannot evaluate the realism of the robotic fish because they
have no strong impression from which to draw comparisons. On the other hand, if
the spectator has at some point in the past seen the real fish in action, then
their excitement at the sight of the robotic model will be greater. For this
reason, we have chosen to have the spectators evaluate the realism of an animatronics
sea bream, a species of fish well known to Japanese spectators.
5. What is the future for animatronics?
It can be speculated
that animatronics will not be a large player in the future of cinematic special
effects and theme parks. Because of the growing ease and versatility of
computer graphics, animatronics are being used less and less to render
life-like fantasy creatures in movies. It is much less expensive to create a
digital version of imaginary monsters, then to build them in a life-like size.
The other main use for animatronics, theme parks, has also seen a decline in
the need for mechanized puppets. Newer theme parks are built around attractions
such as roller-coasters and the importance of visual stimulation such as animatronics
figures has been downplayed in favor of the thrill of an adrenaline rush.
Furthermore, the initial wow-factor which applied to animatronics when the
Enchanted Tiki Room has worn off because of an audience used to seeing many the
technological marvels on television and through the Internet. Nevertheless,
animatronics (and their father, the puppet) have played a large role in the
theatre for a long time and that is unlikely to change unless theatre as a
whole becomes less important with the easy accessibility of movies and
television.
6. Conclusion
From the study of
animatronics we can say that animatronics figures are often used in movies to
create grand special effects. Animatronics has over digital effects in some
movies is more realistic close-up shot. Animatronics figures are not designed
to be intelligent; instead they have been created mainly to entertain.
Animatronics imitates the movements of intelligent characters with pre
programmed motions, words and songs. Animatronics figures move by various types
of motors and actuators. It can be speculated that animatronics will not be a
large player in future of cinematic and fantasy world.
The main use for
animatronics has decline in the need for mechanized puppets. Nevertheless,
animatronics have played a large role in the theater for long time. In case of robotic fish one fin can control
both the thrust force and its direction simultaneously. Then a compact actuator
can be constructed. For robotic fish, the fins flexibility can be utilized
actively. It is therefore possible to improve the propulsion performance. For
robotic fish realistic movement becomes possible by making the oscillating fin
propulsion control system and buoyancy control system. Transmission of radio
signals under water is possible for robotic fish control.
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(Science of Ships)
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[Abstract] [PDF Full-Text (268KB)]
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