Obstacle Avoidance
Obstacle Avoidance problems involve a person whose direct path is blocked by an obstacle. The person must take a detour (e.g., go around the obstacle) to reach the destination. These problems test path planning and alternative route reasoning in direction sense contexts.
What You'll Learn
Introduction to Obstacle Avoidance
Obstacle Avoidance problems involve a person whose direct path is blocked by an obstacle. The person must take a detour (e.g., go around the obstacle) to reach the destination. These problems test path planning and alternative route reasoning in direction sense contexts.
Prerequisites
How to Solve Obstacle Avoidance Problems
Step 1: Identify the intended direction and the obstacle location
Step 2: Determine the required detour (e.g., go around by moving perpendicular to intended direction)
Step 3: Calculate the additional distance or new path coordinates
Step 4: For grid-based obstacles, find the shortest path avoiding the blocked cells
Step 5: For rectangular obstacles, go around by moving in L-shape (e.g., North then East, or East then North)
Step 6: Compare different detour options to find the shortest
Step 7: Express the detour path as a sequence of directions
Example Problem
Example: A person wants to go 10 m East but a 4 m × 4 m obstacle blocks the direct path starting at 3 m East. He decides to go North around it. Describe his detour path. Solution: Step 1: Direct path: East 10 m Step 2: Obstacle occupies from 3 m to 7 m East Step 3: Detour: go North 4 m, then East 10 m, then South 4 m Step 4: Path: North 4 m, East 10 m, South 4 m Answer: North 4 m, then East 10 m, then South 4 m
Pro Tips & Tricks
- The shortest detour around a rectangular obstacle adds 2 × (detour distance)
- If obstacle is at the start, you may need to go around from the beginning
- For multiple obstacles, consider path that avoids all
- In grid-based puzzles, obstacles block specific cells; find path through unblocked cells
- For circular obstacles, detour path is curved, but problems usually use rectangular obstacles
- Always verify that the detour path doesn't intersect other obstacles
Shortcut Methods to Solve Faster
Common Mistakes to Avoid
Practice Worksheets
Practice makes perfect! Work through these worksheets to master Obstacle Avoidance. Each worksheet contains 20 questions with detailed explanations. Start from Worksheet 1 and progress through increasing difficulty levels.
Exam Importance
Obstacle Avoidance is an important topic for various competitive exams. Here's how frequently it appears:
Ready to Master Obstacle Avoidance?
Start with Worksheet 1 and work your way up to expert level! Each worksheet includes: