TESTING

The testing of the bridge was broken into several different criteria that can be grouped as two different sections, the loading of the bridge, and the articulation system of the bridge. The testing criteria were verified by video and photographic evidence for many of the smaller requirements, while the weight, maximum loading, and the dimensions of the bridge were all verified by direct measurements and experimentation.

Overall, the testing went smoothly with only a few minor hiccups. One issue was the wrong code being loaded on the Arduino board when the articulation testing was being conducted that could have damaged the frame of the pulley system. This was solved by quickly resetting the board and locating the correct code, then uploading it to the board before the servos could start rotating again.

Articulation Testing

This test was focused on the articulation aspect of the design. The bridge was raised and the height of the roadway was measured from the tabletop. This test was a pass-fail scenario and the test was successful. The maximum height the roadway is able to reach was measure at 153 mm which exceeds the 140 mm requirement.

The articulation system was designed to be operated using the Arduino board pictured to the right. The green button causes the bridge to be raised and the red button causes the bridge to be lowered. Due to this design, the servos were set into a neutral speed when neither button is pressed meaning the bridge can be held in any desired position in perpetuity as long as the servos are powered.

The secondary object of the test was to verify that the bridge could maintain that position for at least 10 seconds without external intervention. This can be seen in the testing video.

Roadway Clearance Test

This test was a simulation where a block representing a car was passed over the roadway of the deck to show there were no obstructions. The view from one end of the bridge can be seen in the image to the right.

These two images show the block that was used for the testing. The left image shows the width of the block to be 32.01 mm and the right image shows the height to be 24.99 mm. The required dimensions were 32 mm wide and 25 mm tall with a tolerance of 1 mm.

This video shows the testing process. The test was rather simple due to the nature of the requirement being checked. The block was able to pass over the bridge without incident excluding the block rotating and hitting the trusses.

General Testing

The third "test" was a collection of smaller criteria the bridge had to meet that were not notable enough to be given their own distinct test. This included the weight of the bridge, the height of the roadway from the tabletop and the width of the roadway. The image to the left shows the weight of the bridge to be 54 grams, well below the 85 gram limit.

Weight Loading

The final test performed on the bridge design was the loading of 20 kg on the roadway centered on the hole at the midspan. The image to the right shows the testing scenario that was used with a eyebolt running through the center of the roadway and a bucket suspended from the eyebolt. The complete testing video can be seen below