Project 01 / browser experiment / 10–15 minutes
Program a stopping rule.
A simulated wheeled robot reads its distance from a wall. Change its readings and stopping threshold, then investigate when its command changes.
70 cm is above the 30 cm threshold.
See the rule and test it
if reading is missing:
STOP
else if distance <= threshold:
STOP
else:
MOVE FORWARDSet the threshold to 30 cm. Predict the commands at 31, 30 and 29 cm, then try them. What changes when the reading disappears?
This model changes a command; it does not simulate movement, braking, noisy readings or real hardware. It uses a fixed rule, not AI. A physical robot needs additional safeguards and testing.
Turn a demonstration into an experiment
A robotics project becomes more useful when you predict an outcome, change one condition and compare the result with your prediction. For the stopping rule, use the same threshold and vary the reading. Then keep the reading fixed and vary the threshold.
| Reading | Expected command | What it checks |
|---|---|---|
| 31 cm | Move forward | Just above the threshold. |
| 30 cm | Stop | The exact boundary counts as a stop. |
| 29 cm | Stop | Below the threshold. |
| Missing | Stop | The program’s fallback for unavailable data. |
A real vehicle does not stop instantaneously. Speed, braking distance, sensor delay and measurement error would affect a physical design. This experiment isolates the decision rule so you can explain it clearly before tackling those complications.
Project 02: choose measurements for a mission
Open the robot sensor activity. Choose between reading a label, finding a wall in murky water and comparing temperatures at different depths. Select sensors, check the feedback, then explain why each device belongs in your design.
Extend it: remove one reading. What information is now missing? A longer equipment list is not the goal; a reasoned choice is.
Project 03: design an ROV on paper
Use the Stinky guide and printable engineering worksheet to sketch a robot that retrieves a sample. Label the operator, tether, power supply, motors and feedback path. Compare one of your decisions with the original team’s technical report.
Extend it: move the battery from the vehicle to the surface in your drawing. List the trade-offs you would investigate. This is a design discussion, not a tested wiring plan.
Project 04 / Battery power
How long can your robot run?
A robot needs energy for its motors, sensors and controller. Estimate whether a fictional battery-powered robot could finish a three-hour survey, then change one assumption. These numbers are classroom examples, not specifications for the original Stinky robot.
Start with an energy budget
Imagine a battery rated at 40 watt-hours (Wh), with 80% usable capacity and 90% efficiency from battery to devices. Assume the motors draw an average of 4 watts and the sensors and controller draw another 2 watts: 6 watts (W) in total.
Watts describe how quickly the robot uses energy; watt-hours describe an amount of energy. In this simplified model:
Runtime in hours = battery Wh × usable fraction × efficiency ÷ total watts
40 × 0.80 × 0.90 = 28.8 Wh delivered to the devices.
28.8 Wh ÷ 6 W = 4.8 hours, or 4 hours 48 minutes.
Predict, calculate, compare
- Predict whether doubling the total power draw will double or halve the runtime.
- Use the formula above or open the battery runtime calculator on ChargerUniverse. Choose “Nominal energy in Wh” and enter 40 Wh, 80% usable capacity, 90% discharge efficiency and a 6 W total output-side load.
- Try each case below, keeping usable capacity and efficiency unchanged. Record your runtime estimate and whether it exceeds the three-hour mission.
| Case | Battery energy | Total load |
|---|---|---|
| Starting design | 40 Wh | 6 W |
| Higher power draw | 40 Wh | 12 W |
| Larger battery | 80 Wh | 6 W |
Check your results
The starting design lasts 4 hours 48 minutes. At 12 W it lasts 2 hours 24 minutes, which falls short of three hours. With an 80 Wh battery and a 6 W load it lasts 9 hours 36 minutes. Doubling the load halves runtime; doubling energy doubles runtime when all other assumptions stay fixed.
What has the model left out?
A real robot’s power draw changes as motors start, stall or push against water. Battery age, temperature and discharge limits can affect available energy. A larger battery can also add weight and change the robot’s power needs, so the last case is a mathematical comparison, not a guaranteed upgrade.
Extend it: add a fictional 2 W light to the starting design. Recalculate with an 8 W total load, then explain why an estimate above three hours still needs a margin and measurement before a real mission.
This is a paper exercise, not battery selection or wiring instructions. ChargerUniverse is another site from this guide’s publisher; the complete exercise and formula are available here without opening the calculator.
Where does AI fit?
The simulator above follows a fixed rule; it does not train a model. To explore the distinction, try the four scenarios in robotics vs artificial intelligence. Ask whether a human, an explicit rule or a trained model makes the particular decision.
For teachers and clubs
Use the activities separately or combine all four into a 60–75 minute session with time to compare results. Learners should be comfortable comparing numbers and explaining a choice; the battery exercise also uses percentages and division. No programming background is assumed. For a film-led lesson, start with the Spare Parts discussion worksheet, then move from the team’s decisions to a design of your own.
- Look for evidence: can a learner connect a claim to a reading, test result or source?
- Ask for a limitation: what has the model or sketch left out?
- Invite revision: what changed after a failed prediction?
The activities run without an account. They do not ask for student names or store submitted answers. On the public site, analytics can count activity use without collecting the learner’s answers. Teachers may print and share the original exercises for classroom use.
Ready for physical hardware?
SeaPerch’s official build resources offer a route into building an underwater ROV. Follow the programme’s current materials, instruction and supervision guidance. Our browser activities and paper worksheet are not a substitute for its physical build instructions.
Sources & scope
- The real Carl Hayden team and its original sources — historical context.
- SeaPerch education resources — further engineering lessons and programme-specific standards mappings.
These are original beginner exercises, not a certified curriculum or claims of hands-on hardware testing. The simulation checks a simplified control rule; it does not model a real robot’s dynamics.