Waypoint mission creation in Drone Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of waypoint list creation

What is the output of this code that creates a list of waypoints with latitude and longitude?

Drone Programming

waypoints = []
for i in range(3):
    waypoint = {'lat': 40.0 + i*0.01, 'lon': -74.0 - i*0.01}
    waypoints.append(waypoint)
print(waypoints)

A [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.01}, {'lat': 40.01, 'lon': -74.01}]

B [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.0, 'lon': -74.0}, {'lat': 40.0, 'lon': -74.0}]

C [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.0}, {'lat': 40.02, 'lon': -74.0}]

D [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.01}, {'lat': 40.02, 'lon': -74.02}]

💡 Hint

Look at how latitude and longitude change with each loop iteration.

The loop adds 0.01 to latitude and subtracts 0.01 from longitude each time, creating three distinct waypoints.

🧠 Conceptual

intermediate

Understanding waypoint altitude setting

In a waypoint mission, why is it important to set the altitude for each waypoint?

A To ensure the drone flies at the correct height avoiding obstacles and maintaining safety.

B To make the drone fly faster between waypoints.

C To reduce the battery consumption by flying lower always.

D To change the drone's camera angle automatically.

💡 Hint

Think about what altitude controls in drone flight.

Altitude controls the height of the drone, which is critical for obstacle avoidance and safe flight.

🔧 Debug

advanced

Identify the error in waypoint mission code

What error will this code produce when creating waypoints for a mission?

Drone Programming

waypoints = [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.01}]
for wp in waypoints:
    wp['alt'] = 100
    wp = {'lat': 41.0, 'lon': -75.0, 'alt': 150}
print(waypoints)

A TypeError because dictionary assignment is invalid inside loop

B No error; output is [{'lat': 40.0, 'lon': -74.0, 'alt': 100}, {'lat': 40.01, 'lon': -74.01, 'alt': 100}]

C No error; output is [{'lat': 41.0, 'lon': -75.0, 'alt': 150}, {'lat': 41.0, 'lon': -75.0, 'alt': 150}]

D No error; output is [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.01}]

💡 Hint

Consider what happens when you assign a new dictionary to the loop variable.

Assigning a new dictionary to 'wp' inside the loop does not change the original list elements; only the 'alt' key is added to each original waypoint.

📝 Syntax

advanced

Syntax error in waypoint mission dictionary comprehension

Which option correctly creates a dictionary of waypoints with keys as indices and values as lat-lon tuples?

Drone Programming

waypoints = {i: (40.0 + i*0.01, -74.0 - i*0.01) for i in range(3)}

A {i: (40.0 + i*0.01, -74.0 - i*0.01) for i in range(3)}

B {i: (40.0 + i*0.01, -74.0 - i*0.01) if i < 3 for i in range(3)}

C {i: (40.0 + i*0.01, -74.0 - i*0.01) for i in range(3):}

D {i: (40.0 + i*0.01, -74.0 - i*0.01) for i range(3)}

💡 Hint

Check the correct syntax for dictionary comprehensions in Python.

Option A uses the correct syntax: {key: value for variable in iterable}. Other options have syntax errors.

🚀 Application

expert

Calculate total mission distance from waypoints

Given a list of waypoints with latitude and longitude, which code correctly calculates the total straight-line distance (in degrees) between consecutive waypoints?

Drone Programming

waypoints = [{'lat': 40.0, 'lon': -74.0}, {'lat': 40.01, 'lon': -74.01}, {'lat': 40.02, 'lon': -74.02}]
total_distance = 0
for i in range(len(waypoints)-1):
    wp1 = waypoints[i]
    wp2 = waypoints[i+1]
    dist = ((wp2['lat'] - wp1['lat'])**2 + (wp2['lon'] - wp1['lon'])**2)**0.5
    total_distance += dist
print(round(total_distance, 5))

A 0.01

B 0.02

C 0.02828

D 0.04

💡 Hint

Use the Pythagorean theorem to find distance between points.

Each segment distance is sqrt((0.01)^2 + (0.01)^2) = 0.014142, total for two segments is 0.028284, rounded to 0.02828.

Practice

1. What is the main purpose of creating a waypoint mission for a drone?

easy

A. To make the drone fly automatically through specific GPS points

B. To manually control the drone with a remote

C. To charge the drone's battery faster

D. To change the drone's camera settings

Solution

1. Step 1: Understand waypoint missions

   Waypoint missions are designed to let drones fly automatically through set GPS points without manual control.

2. Step 2: Compare options

   Only To make the drone fly automatically through specific GPS points describes automatic flight through GPS points, which matches the purpose of waypoint missions.

3. Final Answer:

   To make the drone fly automatically through specific GPS points -> Option A

4. Quick Check:

   Waypoint mission = automatic GPS flight [OK]

Hint: Waypoint missions automate flight through GPS points [OK]

Common Mistakes:

• Confusing manual control with automatic missions
• Thinking waypoint missions change camera or battery
• Assuming speed control is the main purpose

2. Which of the following is the correct way to add a waypoint with latitude, longitude, and altitude in a drone mission code snippet?

easy

A. waypoint_add(100, 34.05, -118.25)

B. add_waypoint(altitude=100, lat=34.05, long=-118.25)

C. addWaypoint(34.05, -118.25)

D. add_waypoint(latitude=34.05, longitude=-118.25, altitude=100)

Solution

1. Step 1: Identify correct parameter names and order

   The standard is to specify latitude, longitude, and altitude clearly, usually with named parameters or in order.

2. Step 2: Check each option

   add_waypoint(latitude=34.05, longitude=-118.25, altitude=100) uses clear parameter names and correct order. Others have wrong names, missing altitude, or wrong order.

3. Final Answer:

   add_waypoint(latitude=34.05, longitude=-118.25, altitude=100) -> Option D

4. Quick Check:

   Correct parameter names and order = add_waypoint(latitude=34.05, longitude=-118.25, altitude=100) [OK]

Hint: Use clear latitude, longitude, altitude parameters [OK]

Common Mistakes:

• Using wrong parameter names like lat or long instead of latitude/longitude
• Omitting altitude
• Wrong function name or missing parameters

3. Given the following code snippet for a waypoint mission:

mission = []
mission.append({'lat': 40.0, 'lon': -74.0, 'alt': 50})
mission.append({'lat': 40.1, 'lon': -74.1, 'alt': 60})
speed = 10
print(len(mission), mission[1]['alt'], speed)

What will be the output?

medium

A. 2 60 10

B. 2 50 10

C. 1 60 10

D. 2 60 0

Solution

1. Step 1: Count waypoints in mission list

   Two waypoints are appended, so len(mission) is 2.

2. Step 2: Access altitude of second waypoint and speed

   mission[1]['alt'] is 60, and speed is set to 10.

3. Final Answer:

   2 60 10 -> Option A

4. Quick Check:

   Waypoints=2, altitude=60, speed=10 [OK]

Hint: Count list items and check dictionary keys carefully [OK]

Common Mistakes:

• Confusing index 0 and 1 for second waypoint
• Mixing altitude values
• Ignoring speed variable

4. Identify the error in this waypoint mission code snippet:

mission = []
mission.add({'latitude': 35.0, 'longitude': -120.0, 'altitude': 80})
speed = 15
print(len(mission))

medium

A. Incorrect variable name 'speed'

B. Using 'add' method instead of 'append' for list

C. Missing altitude value in waypoint dictionary

D. Print statement syntax error

Solution

1. Step 1: Check list method usage

   Python lists use 'append' to add items, not 'add'. Using 'add' causes an error.

2. Step 2: Verify other parts

   Altitude is present, variable names are correct, and print syntax is valid.

3. Final Answer:

   Using 'add' method instead of 'append' for list -> Option B

4. Quick Check:

   List method must be append, not add [OK]

Hint: Use append() to add items to a list [OK]

Common Mistakes:

• Using set methods like add() on lists
• Forgetting to include altitude
• Typos in variable names

5. You want to create a waypoint mission where the drone flies through three points with these coordinates and altitudes using dictionary keys 'latitude', 'longitude', 'altitude': 1) (34.0, -117.0, 100m) 2) (34.1, -117.1, 120m) 3) (34.2, -117.2, 110m) You also want the drone to fly at 8 m/s between points. Which code snippet correctly creates this mission and sets the speed?

hard

A. mission = [{'lat':34.0, 'lon':-117.0, 'alt':100}, {'lat':34.1, 'lon':-117.1, 'alt':120}, {'lat':34.2, 'lon':-117.2, 'alt':110}]
speed = 8

B. mission = []
mission.add({'lat':34.0, 'lon':-117.0, 'alt':100})
mission.add({'lat':34.1, 'lon':-117.1, 'alt':120})
mission.add({'lat':34.2, 'lon':-117.2, 'alt':110})
speed = 8

C. mission = []
mission.append({'latitude':34.0, 'longitude':-117.0, 'altitude':100})
mission.append({'latitude':34.1, 'longitude':-117.1, 'altitude':120})
mission.append({'latitude':34.2, 'longitude':-117.2, 'altitude':110})
speed = 8

D. mission = [{'lat':34.0, 'lon':-117.0}, {'lat':34.1, 'lon':-117.1}, {'lat':34.2, 'lon':-117.2}]
speed = 8

Solution

1. Step 1: Check waypoint creation with correct keys

   mission = [] mission.append({'latitude':34.0, 'longitude':-117.0, 'altitude':100}) mission.append({'latitude':34.1, 'longitude':-117.1, 'altitude':120}) mission.append({'latitude':34.2, 'longitude':-117.2, 'altitude':110}) speed = 8 uses 'latitude', 'longitude', and 'altitude' keys consistently, matching the given data.

2. Step 2: Verify method to add waypoints and speed setting

   mission = [] mission.append({'latitude':34.0, 'longitude':-117.0, 'altitude':100}) mission.append({'latitude':34.1, 'longitude':-117.1, 'altitude':120}) mission.append({'latitude':34.2, 'longitude':-117.2, 'altitude':110}) speed = 8 uses append() correctly to add waypoints and sets speed to 8 m/s as required.

3. Step 3: Eliminate incorrect options

   mission = [{'lat':34.0, 'lon':-117.0, 'alt':100}, {'lat':34.1, 'lon':-117.1, 'alt':120}, {'lat':34.2, 'lon':-117.2, 'alt':110}] speed = 8 uses different keys ('lat', 'lon', 'alt') which are inconsistent with required keys. mission = [] mission.add({'lat':34.0, 'lon':-117.0, 'alt':100}) mission.add({'lat':34.1, 'lon':-117.1, 'alt':120}) mission.add({'lat':34.2, 'lon':-117.2, 'alt':110}) speed = 8 uses 'add' which is invalid for lists. mission = [{'lat':34.0, 'lon':-117.0}, {'lat':34.1, 'lon':-117.1}, {'lat':34.2, 'lon':-117.2}] speed = 8 misses altitude values.

4. Final Answer:

   mission = [] mission.append({'latitude':34.0, 'longitude':-117.0, 'altitude':100}) mission.append({'latitude':34.1, 'longitude':-117.1, 'altitude':120}) mission.append({'latitude':34.2, 'longitude':-117.2, 'altitude':110}) speed = 8 -> Option C

5. Quick Check:

   Correct keys + append() + speed = mission = [] mission.append({'latitude':34.0, 'longitude':-117.0, 'altitude':100}) mission.append({'latitude':34.1, 'longitude':-117.1, 'altitude':120}) mission.append({'latitude':34.2, 'longitude':-117.2, 'altitude':110}) speed = 8 [OK]

Hint: Use append() with full keys and set speed separately [OK]

Common Mistakes:

• Using add() instead of append()
• Missing altitude in waypoints
• Mixing key names inconsistently