Creation By Error
In the project Creation By Error, the data being displayed was collected specifically for this project with a custom robot. The robot consisted of an Arduino Micro, a tact button, a small servo motor, an ultrasonic sensor, custom built “L-brackets” and the Node.js programming framework. The “L-brackets” were designed to allow the servo motor to rotate the ultrasonic sensor around the x-axis. The sensor was able to rotate a total of 180 degrees, where the 0 degrees was pointing the sensor directly down towards the floor and the 180th degree was pointing up towards the ceiling. The robot was set up facing an empty wall that stood at a height of 2.4384 meters (8 feet) and was 160 cm away from the wall. The robot was turned on and was left uninterrupted for one hour. During the one hour period, the device collected a total of over 100,000 data points which were distance measurements. These measurements were gathered at every angle between 0 and 180 degrees. Each angle that the robot measured had a total between ~800 to ~1,200 unique data points. Using all of the data points, the mean distance for each angle that the robot scanned was calculated. Doing this calculation provided good insight into how the robot saw and interpreted the space it was in front of. It also shows the fluctuation and anomalies in the digital measurement over time.
For each angle that the robot scanned, the real physical distance was also calculated. This was done using some trigonometry equations. The distance from the sensor to the wall was calculated by taking the height that the sensor was from floor and the angle that the sensor was pointing. This allowed us to calculate the hypotenuse of Triangle A in Figure 1 above. Keep in mind that the hypotenuse distance was the distance from the sensor to the floor at a specific angle — since there was a wall blocking this sensor trajectory, determining the real distance from the sensor to the wall was still needed. To account for the wall and get an accurate calculation for the distance from the sensor to the wall, the base of Triangle A was calculated next, then the difference between Triangle A’s base and the known distance from the robot to the wall was calculated. That answer was used to calculate Triangle B’s base length. Finally we calculated the hypotenuse of Triangle B and subtracted that result from the hypotenuse of Triangle A — this final answer is the distance from the ultrasonic sensor to the wall. This allowed me to know what the real distance from the sensor to the wall and be able to compare the known physical distances to the digitally measured distances. Having these two values for each degree allowed for a comparison to be made about the accuracy and precision of my robots in both the physical and digital worlds.
To visualize and communicate the margin of error between the digital measurements and the physical world, a to scale sculpture was built and hung from the ceiling. The materials used to fabricate the sculpture was wooden dowels, white tarp, string and wood staples.The dowels were used to create 9 wooden ribs representing 9 measurements at different angles. The size of the ribs were dependent on the difference between the physical and digital measurements. Lastly the tarp was cut to size and draped over ribs of the sculpture.
The interest in taking these robotic measurements and comparing them to the known distances was to investigate, and generate dialog about the reliance society has on technology and at times a perception of “perfectness” that the digital can create. This “perfectness” can sometimes create a blind trust in what people accept from technology. By showcasing the error in the digitally collected measurements, I hope to spark critically thought about what information people receive through digital mediums.
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