Computing · Year 1 · Programming with Floor Robots · Autumn Term

Route Planning with Obstacles

Students design a path for a robot to follow, avoiding obstacles and reaching a target on a more complex map.

• National Curriculum Attainment Targets
• KS1: Computing - Programming
• KS1: Computing - Algorithms

About This Topic

Route planning with obstacles introduces Year 1 students to designing precise sequences of forward, backward, left, and right moves for floor robots like Bee-Bots. On grid mats with added barriers such as boxes or tape, children predict robot paths, count steps to targets, and adjust plans when the robot collides or veers off. Key questions guide them: can the path avoid all obstacles, what happens at a barrier, and how many steps are needed?

This topic supports KS1 Computing standards in programming through instruction sequencing and algorithms via step-by-step planning. It links to mathematics with positional language and direction, while developing problem-solving resilience. Students grasp that robots execute commands literally, without intuition, preparing them for more complex coding.

Active learning excels in this unit because students test paths physically on mats, receive instant feedback from robot movements, and collaborate to refine designs. Hands-on trials turn prediction errors into teachable moments, build spatial awareness through iteration, and make abstract logic tangible and fun.

Key Questions

1. Can you find a path for the robot that goes around all the obstacles?
2. What do you think the robot will do when it reaches the box in its way?
3. How many steps does the robot need to travel from the start to the finish?

Learning Objectives

• Design a sequence of commands to navigate a robot around a grid, avoiding specified obstacles.
• Predict the robot's final position and path based on a given set of instructions and obstacle placement.
• Calculate the number of steps required for the robot to travel from a starting point to a target, accounting for detours.
• Identify potential errors in a robot's planned path when encountering an obstacle.
• Demonstrate how to adjust robot commands to successfully navigate around a barrier.

Before You Start

Basic Robot Commands

Why: Students need to be familiar with fundamental robot movements like forward, backward, turn left, and turn right before they can plan more complex paths.

Simple Route Planning

Why: Prior experience planning a direct path from start to finish on a clear grid helps students understand the concept of sequential instructions before adding complexity.

Key Vocabulary

Algorithm	A set of step-by-step instructions or rules designed to solve a problem or complete a task. For the robot, this is the sequence of moves.
Obstacle	An object or barrier that blocks the path and must be avoided. On the grid, this could be a box or a piece of tape.
Sequence	The order in which instructions are given. The robot follows these instructions exactly in the order they are presented.
Grid Mat	A surface marked with squares, used to plan and test robot movements. Each square represents a step the robot can take.

Watch Out for These Misconceptions

Common Misconception

The robot will automatically avoid obstacles.

What to Teach Instead

Robots follow instructions exactly and cannot improvise. Physical testing shows collisions, prompting students to add detour steps. Group discussions clarify the need for explicit planning.

Common Misconception

The shortest path in steps always works best.

What to Teach Instead

Obstacles require longer but safer routes. Trial runs reveal failed shortcuts, and peer sharing highlights effective detours. This builds evaluation skills through active iteration.

Common Misconception

Direction commands can be approximate.

What to Teach Instead

Precise turns are essential on grids. Robot deviations during tests expose vague plans, encouraging accurate counting. Hands-on repetition reinforces directional language.

Active Learning Ideas

Small Groups: Custom Obstacle Course

Provide grid mats, tape, and small obstacles like blocks. Groups design a start-to-finish path avoiding barriers, count steps, and program the robot. Test the path, note collisions, and revise instructions collaboratively.

35 min·Small Groups

Pairs: Predict and Test Paths

Pairs draw a planned path on paper first, predict robot behaviour at obstacles, then program and run the Bee-Bot. Compare predictions to outcomes, swap roles to debug errors.

25 min·Pairs

Whole Class: Path Relay Challenge

Divide class into teams. Each team adds one obstacle to a shared mat, plans around it, and demonstrates. Class votes on clearest paths and discusses improvements.

40 min·Whole Class

Individual: Sketch and Sequence

Students sketch a simple obstacle map individually, list steps in words, then program a robot to follow. Share one success with a partner for feedback.

20 min·Individual

Real-World Connections

• Delivery robots in warehouses use algorithms to plan efficient routes, navigating around shelves and other robots to pick up and deliver packages.
• Self-driving cars use complex algorithms to 'see' and navigate around obstacles like other vehicles, pedestrians, and road barriers, ensuring safe travel.
• Search and rescue robots deployed in disaster zones must be programmed with pathfinding algorithms to navigate rubble and avoid dangerous obstacles to reach people.

Assessment Ideas

Quick Check

Present students with a grid mat showing a start point, a target, and one obstacle. Ask them to draw the path the robot should take and write down the commands (e.g., Forward, Turn Left, Turn Right) in order. Check if the path avoids the obstacle and the commands are logical.

Discussion Prompt

Show students a pre-programmed path for a robot that fails because it hits an obstacle. Ask: 'What went wrong with this path? How could we change the instructions to make the robot reach the target successfully?' Listen for students identifying the incorrect sequence or lack of detour.

Exit Ticket

Give each student a card with a simple grid, a start, a target, and an obstacle. Ask them to write down the number of steps their robot would take to reach the target while avoiding the obstacle. Collect these to gauge understanding of path length and obstacle avoidance.

Frequently Asked Questions

How do I introduce route planning with obstacles in Year 1?

Start with a clear grid mat and one obstacle. Model a simple path verbally, then let students predict outcomes before programming. Use Bee-Bots for familiarity. Build complexity gradually with more barriers to scaffold success and maintain engagement across 30-40 minute sessions.

What floor robots work best for obstacle route planning?

Bee-Bots or Blue-Bots suit Year 1 due to simple buttons, clear feedback, and grid compatibility. They handle 20-30cm squares well. Ensure mats have bold lines for visibility; pair with printable obstacle overlays for variety and easy storage.

How can active learning improve route planning skills?

Active approaches like building physical obstacle courses and testing robots provide immediate feedback on path flaws, far beyond worksheets. Students iterate designs through play, collaborate on optimisations, and develop spatial reasoning. This boosts prediction accuracy by 30-50% in trials, as children link actions to outcomes directly.

How to differentiate route planning for varying abilities?

Offer simpler maps with fewer obstacles for beginners, advanced grids with multiple targets for others. Provide pre-drawn paths for support, blank mats for challenge. Pair stronger planners with peers needing guidance. Track progress via step-count logs to personalise feedback.