- How to Use
is a simple, free software program that runs within your web browser.
Train yourself to judge the wingbeat frequency of a bird or ornithopter
with this program.
1. You may need
to download a Java
plug-in to run FlapRate in your web browser.
2. The program
will open in a separate window. If your computer asks if you want
to allow the program to run, say yes. You should see several buttons
that look like this:
can display several different animations: two-wing, four-wing, and
a flashing LED light. Training yourself with a variety of different
animations makes it easier to transfer your skills to real-life
situations. Use the pull-down menu in the upper left corner of the
FlapRate display area to make your selection.
The "Animation" button starts the animation. To vary the
speed, click your mouse anywhere in the display area: farther left
for slower speeds, or farther right for faster speeds. When you
release the mouse button, the wings will flap once, and the flapping
rate in Hz (cycles per second) will appear beneath the animation.
5. The "Quiz"
button causes the animation to run for several seconds, without
showing the flapping rate. Once the animation stops, you can type
your guess into the box and click the "Enter" button.
Your percent accuracy will appear beneath the animation. The correct
answer replaces your guess in the text box.
6. If you repeat
the quiz more than once, FlapRate will calculate your overall score
by averaging all of your individual scores. Your overall score is
not saved when you close the FlapRate window.
You might be wondering why the flapping rate sometimes fluctuates
while running the animation. This happens because your computer
pauses to do other things while the program is running. Instead
of trying to force the animation to run at a particular speed, FlapRate
simply keeps track of how fast the animation is actually running.
final value displayed under the animation at the end of each run
reflects the average speed for the entire run. This average value
is also used for scoring the quiz.
You might also wonder why we only show two wing positions: up and
down. The animation would be smoother if we could show a multitude
of wing positions throughout the flapping cycle. Unfortunately,
the number of frames we can present per wingbeat cycle is limited
by the program execution speed and by the refresh rate of your monitor.
Suppose your monitor refreshes at 60 Hz, and the wings are flapping
at 10 Hz. We could only hope to show 6 frames in each flapping cycle.
Through the persistance of vision phenomenon, the rapidly sequenced
frames might appear to merge, something like this:
With a real
ornithopter, the wings are pretty much a blur until they come to
rest at the end of each stroke. For that reason, showing them only
in the extreme positions may be the more realistic option, at least
at the higher flapping rates.
4. If we actually
showed the intermediate wing positions at a given frame rate such
as 60 Hz, you would be able to judge the flapping rate by the difference
in wing angle from one frame to the next. That particular cue will
not be available to help you judge flapping rates in the real world.
5. When you
click the "Animation" or "Quiz" button, the
animation plays for a random amount of time. This way, you can't
judge the flapping rate simply by counting the total number of wingbeats.
6. I've added
a new feature, which provides wingbeat sounds to match the animations.
This additional sensory information might make it easier to judge
the flapping rate. However, you can turn the sound off if you want
to work on your ability to judge flapping rate based on the visual