Hi. I'm Fran and this nifty device is the Go Direct Acceleration.
This device contains several sensors packed into a nice small package here.
It includes one 3-axis accelerometer at plus or minus 16 g's,
a second 3-axis accelerometer at plus or minus 200 g's, plus a 3-axis
gyroscope and altimeter. Very useful device. In order to use it,
you can either connect via USB, or you can connect via Bluetooth.
Since you'll probably be using this with motion steady's, you'll probably want
to connect via Bluetooth most of the time. In order to connect,
first I need to turn on the sensor. The flashing red light indicates that it's
ready to connect. In graphical analysis, I'll choose Sensor Data Collection,
and then I'll have to find what sensors are available. Using the ID number that's
on the sensor, I'm going to look for that ID number in the list of sensors.
I know that this one ends in 7H4. So, I'm going to look for the device that has
7H4 at the end of it. Once I found it, I can connect. Since the sensor has so
many channels, you're going to want to choose which channels to use when you're
doing your particular experiment. The list of sensor channels is found
in this menu. In this case, the directions for X, Y, and Z
are shown in this little icon on the label. The X direction is along the
length of the sensor, so that's what I'm going to use for my
first experiment. A popular experiment is to do collision studies.
I want to see if I can take the collision of this cart with the end of the track,
and decrease the acceleration to make it safer. In order to do that,
I'm going to need to attach it to my cart and I'm going to need to make some
adjustments in the software. To attach it to the cart,
I'm going to use a shim that comes with the sensor, place it on the cart,
place the sensor on top, and use the bracket and two screws that
come with the dynamics cart and track system to attach it.
I also need to adjust the software because collisions take place over a very short
amount of time. So, you need to increase the data collection rate. In this case,
I'm going to change the data collection rate from 50 samples per second to 300
samples per second. I'm also going to decrease the time for data collection
from 1 minute to 3 seconds. Collisions take very little time.
Now that I've set up the software and the device, I'm going to try out a couple
of different barriers that I've made. So, I'm going to try this barrier first,
place it at the end of the track, and start collecting some data
from my collision. All right. I can use the Statistics function
in Graphical Analysis, to determine what my maximum
acceleration was, or in this case, since it's a negative acceleration,
what the minimum value is. So, looks like the minimum value is -156.699
meters per second squared. That's a lot of acceleration.
I'm going to switch barriers from this one to this one.
Now, when I collect data, I should see a different result.
So, as you can see, this collision is not going to have as large an acceleration.
Once again, we can check using the Statistics. And in this case,
the minimum value is -41.337 meters per second squared. I can also compare both
collisions on the same set of axes by choosing to show both of the data sets
at once, and you can see the dramatic difference. Since the sensor has so
many channels, you don't want to use it just for acceleration.
I'm going to do a different experiment. When I select New Experiment
in the software, it's going to select the same device that I was already using.
So, I don't have to find the name in the sensor list again.
However, I do need to adjust the channel. In this case, I'm going to put my device
onto a turntable. Again, the three axes are placed on the label,
so that you can see that if I'm going to look at rotation in this direction,
I'm going to want to use the vertical axis, which is labeled Z. So in this case,
when I choose Sensor Channels, I'm going to choose the Z-axis gyroscope.
I'm also going to adjust the time for this experiment, but not the data
collection rate. 15 seconds is plenty for this experiment. I'm going to collect my
data and start the turntable turning. Turntables typically have a couple
of different rotation rates, so I'm going to change the rotation rate
so I can compare, and then turn it off. So now, I can examine this data and look
at what the rotation rate was in each speed for the turntable.
The statistics say that at the higher rate of rotation, the average was -4.871
radians per second. Looking at the slower rate of rotation and the
statistics again, I can see that the average was -3.599 radians per second.
These are only two of the possible uses for the Go Direct Acceleration Sensor.
With its small size, it's the perfect device to connect
to your phone, put in your pocket, and take on a rollercoaster or other
amusement park ride. We'd love to hear your suggestions.
For more information on this sensor, please refer to our website.