Name: ______________________________
Date: ____________________
Week 7
Planning an Autonomous Mission
Turn a real job into a plan: requirements, constraints, a flowchart, and a safe autonomous mission.
60-75 minutes
Key ideas
Autonomous vs remote-controlled
There are two ways a robot can do a job. When it is remote-controlled, a person steers it in real time, deciding every move. When it is autonomous, the robot runs its own program and uses its sensors to decide for itself, with no one steering.
Requirements, constraints, and criteria
Before you build, you plan. A requirement is what the robot MUST do - 'carry the block to the blue zone'. A constraint is a limit you have to work inside - 'in under 30 seconds', 'using only one sensor', 'no bigger than a shoebox'. Criteria are how you will judge success - 'stops inside the zone' and 'never bumps the wall'.
Trade-offs and the engineering design process
You almost never get everything at once. A trade-off is giving up some of one thing to get more of another. A robot that drives fast might miss the sensor reading and crash; slowing it down trades speed for reliability. There is rarely one 'right' answer - you choose the trade-off that best fits your requirements and constraints.
Flowcharts: mapping the program before you code it
A flowchart is a picture of your program's steps. Actions go in rectangles ('drive forward', 'stop'). Decisions go in diamonds and ask a yes/no question ('Wall ahead?'), with one arrow out for 'yes' and one for 'no'. Arrows connect the boxes so you can follow the path the robot will take.
Safe stopping and responsible robotics
An autonomous robot decides on its own, so it needs a way to stop safely - a programmed behavior that halts it when the job is done or when something (or someone) is in the way. Without a safe stop, an autonomous robot can keep driving into a wall or a person.
Autonomous robots in the real world
Autonomous robots already do real jobs - almost always dull, dirty, or dangerous ones, and almost always with people supervising. Looking at real examples helps you plan your own mission: each one senses the world, decides with a program, acts, and has a way to stop safely.
Words to know
- Autonomous:
- Acting on its own: the robot uses its sensors and a program to decide what to do, with no person steering it.
- Remote-controlled:
- Steered by a person in real time, moment by moment, for example with a joystick or an app.
- Requirement:
- Something the robot MUST do to count as doing the mission, like 'reach the drop-off zone'.
- Constraint:
- A limit you have to work inside, like time, size, materials, or budget.
- Criteria:
- The measures you use to judge success, like 'stops within 5 cm of the wall' or 'finishes in under 30 seconds'.
- Trade-off:
- Giving up some of one good thing to get more of another, like going slower to be more reliable.
- Engineering design process:
- The repeating cycle engineers use: plan, build, test, and improve.
- Iteration:
- One trip around the design cycle - testing your plan or robot, finding a problem, and improving it.
- Efficiency:
- Doing the job well with less: fewer steps, less time, or less energy.
- Safe stop:
- A programmed behavior that halts the robot safely when the job is done or something is in the way.
- Responsible robotics:
- Thinking about safety and about when a human should stay in control instead of the robot.
- Flowchart:
- A step-by-step diagram of a program that uses boxes for actions and diamonds for decisions.
Your activity
Write a mission plan
Goal: Turn a small autonomous job into a plan: requirements, constraints, success criteria, and one trade-off you had to weigh.
- Pick one small autonomous mission, like 'drive to the zone and stop' or 'search until you find the target'. Write it at the top of the Mission Planning Brief.
- Fill in the brief: requirements (what it MUST do), constraints (limits like time, size, or one sensor), and criteria (how you'll judge success). Then name one trade-off you had to weigh, such as speed vs reliability.
Write what happened:
Draw the mission flowchart
Goal: Turn the mission plan into a flowchart with action boxes, at least one decision diamond, a loop that checks a sensor, and a safe stop.
- On the flowchart page, start at a 'Start' box and end at a 'Safe stop' box. Put actions in rectangles and each yes/no decision in a diamond, with a 'yes' arrow and a 'no' arrow.
- Your autonomous flowchart must keep checking a sensor (a loop) and must end at a safe stop - the robot stops when the job is done or something is in the way.
Write what happened:
Guided autonomous practice mission
Goal: Run a short autonomous mission - drive to a zone, react to one obstacle, and stop safely - as a rehearsal for next week's final project.
- Build the program straight from your flowchart: a sequence to drive, a loop that keeps checking one sensor, a condition that reacts to an obstacle, and a safe stop when the robot reaches the zone or hits the obstacle.
- Run it, watch it against your success criteria, and note one thing you would improve - that improve step is an iteration, exactly what you'll do more of next week.
Write what happened:
Predict
Write your guess before you test.
Before you run it, predict: will your practice mission meet all of its success criteria on the first try, and which criterion is most likely to fail?
Test and record
Practice mission vs its criteria
Run the guided practice mission from the same start each time. For each run, record what happened and check it against the success criteria in your brief.
Record: Whether each success criterion was met, and what to change for the final project
| Run | Reached the zone? (Y/N) | Reacted to obstacle? (Y/N) | Stopped safely? (Y/N) | What to improve |
|---|---|---|---|---|
Knowledge check
Answer each question. For choice questions, circle the best answer.
A delivery robot drives to a drop-off zone by itself, using its sensors and program, with no one steering. This robot is:
- A.Remote-controlled
- B.Autonomous
- C.Not a robot
- D.Broken
'The robot must reach the blue zone' and 'it has to finish in under 30 seconds'. Which is the requirement and which is the constraint?
- A.Reaching the zone is the requirement; the 30-second limit is the constraint
- B.Reaching the zone is the constraint; the 30-second limit is the requirement
- C.Both are constraints
- D.Both are requirements
In a flowchart, what does a diamond shape mean?
- A.An action the robot takes
- B.A yes/no decision
- C.The end of the program
- D.How long a step takes
Your robot drives fast but sometimes misses its sensor reading and crashes. You slow it down so it reads reliably. This choice is an example of a:
- A.Requirement
- B.Trade-off
- C.Safe stop
- D.Constraint
Why does an autonomous robot need a safe stop in its program?
- A.So it looks finished
- B.So it halts safely when the job is done or something is in the way, instead of driving into it
- C.So it can move faster
- D.So it never needs a sensor
Reflect
Which was harder to write for your mission - the requirements, the constraints, or the criteria - and why?
Describe one trade-off in your plan. What did you give up, and what did you get in return?
Responsible robotics: name one job where an autonomous robot really helps, and one situation where a human should stay in control instead. Explain your thinking.