This resource is a part of the Testing & Troubleshooting lesson series.
Engineers who are developing a technology use a particular approach called the engineering design process. The design process is fundamental to technology and to engineering. Also referred to as technological design, the engineering design process demands critical thinking, the application of technical knowledge, creativity, and an appreciation of the effects of a design on society and the environment. Performance testing is a major part of the engineering design process.
Students submerge their SeaPerch in water and observe how it floats and/or sinks. Ask students to hypothesize what needs to be done to get their SeaPerch to be neutrally buoyant. Students can calculate and add weights in order to get their ROV to a neutrally buoyant state. Note: Teachers may want to refer to the lesson plan: Determination of Mass, Volume, and Ballast.
Once the SeaPerch ROVs have been modified to be neutrally buoyant, explain that the students will test their SeaPerch for buoyancy (in engagement and exploration), guidance, and speed. Through data collection, students can use the testing information to refine or improve the performance of their SeaPerch.
Students will place their SeaPerch in the water (attempt to keep ROVs separate from one another so as not to disturb the water for other robots) and operate each switch to determine which switch controls the vertical thruster, left motor, right motor, forward motion and backward motion. Students will use their observations to fill out the Guidance Testing Documentation Worksheet.
Students should investigate the vertical and horizontal speed of their ROVs. Allow them time to study their ROV’s motions and fill out the Measuring Velocity and Acceleration Worksheet.
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Motion Desired |
Switches |
Up (U) / Down (D) |
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Left Motor On / Off |
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Right Motor On / Off |
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Vertical Thrust Toward Water Surface |
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Horizontal Forward Motion |
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Horizontal Backward Motion |
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Based on your testing, label your switches on your remote box to help you control the SeaPerch ROV.
If you were using an ROV to collect data or perform a task, you would need to know how fast the ROV could move in the water in order to estimate the amount of time required to power the vehicle under water. You would also need this information to determine how quickly you could arrive at your target location.
Testing Question: How do you measure horizontal velocity of the SeaPerch?
Materials:
SeaPerch
Test Tank
Tape
Stop Watches
Meter Stick/Measuring Tape
Directions:
Distance Observations
Data Table 1:
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Distance of Travel |
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Time of SeaPerch in Seconds |
Trials |
Distance A (1st tape mark)(2 feet) |
Distance B (2 feet) |
Distance C (2nd tape mark) (2 feet) |
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1 |
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2 |
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3 |
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Average Time |
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Hint: Distance B reflects the time between 1st and 2nd tape marks and can be found by the following equation:
Distance B = Distance C – Distance A
Velocity Calculations
Note: Convert feet into meters using the following: (1 foot = 0.3048 meters)
Average Velocity = Distance = Meters Seconds Average Time
Data Table 2:
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Distance A |
Distance B |
Distance C |
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Velocity (show your work) |
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Hint: Distance C is the total distance (4 feet)
Graph
On the graph below, create a scatter plot (graph of the data points) for velocity vs. time. Draw a best fit line through your plotted points.
Velocity vs. Time
This resource is a part of the Testing & Troubleshooting lesson series.
This resource is a part of the Testing & Troubleshooting lesson series.
This resource is a part of the Build lesson series.
