Hover condition (thrust = weight) in Drone Programming - Mini Project: Build & Apply

Hover Condition (thrust = weight)

📖 Scenario: You are programming a simple drone control system. To make the drone hover steadily in the air, the thrust force generated by the drone's motors must exactly balance the drone's weight. This means the thrust should be equal to the weight.We will write a small program to check if the drone is hovering by comparing thrust and weight values.

🎯 Goal: Build a program that stores the drone's weight and thrust values, then checks if the drone is hovering by comparing these values. Finally, print a message indicating whether the drone is hovering or not.

📋 What You'll Learn

Create variables for drone weight and thrust with exact values

Create a variable to store the hover tolerance threshold

Use an if-else statement to check if thrust equals weight within the threshold

Print 'Hovering' if thrust equals weight within threshold, else print 'Not hovering'

💡 Why This Matters

🌍 Real World

Drones must maintain stable hover to perform tasks like photography or delivery safely.

💼 Career

Understanding how to compare forces and control conditions is important for drone software developers and robotics engineers.

1

Set up drone weight and thrust variables

Create two variables called weight and thrust with the exact values 10.0 and 9.8 respectively.

Drone Programming

# Create variables weight and thrust with values 10.0 and 9.8
# Your code here

Hint

Use simple assignment statements like weight = 10.0.

2

Add hover tolerance threshold

Create a variable called tolerance and set it to 0.2 to allow a small difference between thrust and weight.

Drone Programming

weight = 10.0
thrust = 9.8
# Create a variable tolerance with value 0.2
# Your code here

Hint

This variable helps us decide if thrust is close enough to weight to hover.

3

Check if drone is hovering

Write an if statement that checks if the absolute difference between thrust and weight is less than or equal to tolerance. Use abs(thrust - weight) <= tolerance as the condition.

Drone Programming

weight = 10.0
thrust = 9.8
tolerance = 0.2
# Write if statement to check if abs(thrust - weight) <= tolerance
# Your code here

Hint

Use the abs() function to get the positive difference.

4

Print hover status

Write a print statement that prints 'Hovering' if hovering is True, otherwise print 'Not hovering'.

Drone Programming

weight = 10.0
thrust = 9.8
tolerance = 0.2
if abs(thrust - weight) <= tolerance:
    hovering = True
else:
    hovering = False
# Print 'Hovering' if hovering is True, else print 'Not hovering'
# Your code here

Hint

Use an if-else to print the correct message based on the hovering variable.

Practice

1. What does the hover condition thrust == weight mean for a drone?

easy

A. The drone's battery is fully charged.

B. The drone will start moving upward quickly.

C. The drone will fall down immediately.

D. The drone stays steady in the air without moving up or down.

Solution

1. Step 1: Understand thrust and weight

   Thrust is the upward force from the drone's propellers, and weight is the downward force due to gravity.

2. Step 2: Analyze the equality condition

   When thrust equals weight, the forces balance, so the drone neither rises nor falls.

3. Final Answer:

   The drone stays steady in the air without moving up or down. -> Option D

4. Quick Check:

   Hover condition means thrust = weight [OK]

Hint: Hover means forces balance: thrust equals weight [OK]

Common Mistakes:

• Thinking thrust > weight means hovering
• Confusing thrust with battery power
• Assuming thrust < weight means hovering

2. Which of the following is the correct way to check if thrust equals weight in drone programming?

easy

A. if thrust == weight:

B. if thrust != weight:

C. if thrust = weight:

D. if thrust => weight:

Solution

1. Step 1: Identify the comparison operator

   In programming, == checks if two values are equal, while = assigns a value.

2. Step 2: Choose the correct syntax

   To check equality, use if thrust == weight: which compares thrust and weight.

3. Final Answer:

   if thrust == weight: -> Option A

4. Quick Check:

   Use '==' for equality check [OK]

Hint: Use '==' to compare values, '=' is for assignment [OK]

Common Mistakes:

• Using single '=' instead of '==' for comparison
• Using '!=' which means not equal
• Using invalid operators like '=>'

3. What will be the output of this code snippet?

thrust = 10
weight = 10
if thrust == weight:
    print('Hovering')
else:
    print('Not hovering')

medium

A. Hovering

B. No output

C. SyntaxError

D. Not hovering

Solution

1. Step 1: Compare thrust and weight values

   Both thrust and weight are set to 10, so thrust == weight is True.

2. Step 2: Determine which branch runs

   Since the condition is True, the code prints 'Hovering'.

3. Final Answer:

   Hovering -> Option A

4. Quick Check:

   10 == 10 is True, so print 'Hovering' [OK]

Hint: Equal values trigger 'Hovering' print [OK]

Common Mistakes:

• Confusing assignment '=' with comparison '=='
• Expecting 'Not hovering' when values are equal
• Missing indentation causing syntax errors

4. Find the error in this code that checks hover condition:

if thrust = weight:
    print('Hovering')

medium

A. Missing colon ':' after if statement

B. Using '=' instead of '==' for comparison

C. Incorrect indentation of print statement

D. Variable names are invalid

Solution

1. Step 1: Check the if statement syntax

   The code uses = which assigns value, not compares values.

2. Step 2: Correct the operator for comparison

   Replace = with == to properly check if thrust equals weight.

3. Final Answer:

   Using '=' instead of '==' for comparison -> Option B

4. Quick Check:

   Use '==' to compare, '=' assigns [OK]

Hint: Use '==' in if conditions, '=' is assignment [OK]

Common Mistakes:

• Confusing '=' and '=='
• Ignoring missing colon errors
• Assuming indentation error instead of operator error

5. You want the drone to print 'Hovering' only when thrust equals weight, and 'Adjusting' otherwise. Which code correctly implements this?

thrust = 15
weight = 15
# Your code here

hard

A. if thrust = weight:
print('Hovering')
else:
print('Adjusting')

B. if thrust != weight:
print('Hovering')
else:
print('Adjusting')

C. if thrust == weight:
print('Hovering')
else:
print('Adjusting')

D. if thrust > weight:
print('Hovering')
else:
print('Adjusting')

Solution

1. Step 1: Use correct equality check

   The condition must use == to check if thrust equals weight.

2. Step 2: Use else for other cases

   If thrust is not equal to weight, print 'Adjusting' to indicate change needed.

3. Final Answer:

   if thrust == weight: print('Hovering') else: print('Adjusting') -> Option C

4. Quick Check:

   Use '==' for equality, else for other cases [OK]

Hint: Use if thrust == weight else for other cases [OK]

Common Mistakes:

• Using '=' instead of '==' in if condition
• Reversing condition with '!='
• Using '>' which is not hover condition