Define the environment
Represent the world as an occupancy grid with start and goal markers, and check obstacle cells are correctly annotated.
Compute A* paths on a grid. Assess path length and obstacles.
A* (A-star) is a graph-search algorithm that finds a least-cost path to a goal using a heuristic to guide exploration. On occupancy grids it balances travelled distance and heuristic distance; common failure modes include inadmissible heuristics, grid resolution artefacts, lack of dynamic-obstacle handling and no path smoothing for real robot controllers.
Learning concept · Not a validated service
A* (A-star) is a graph-search algorithm that finds a least-cost path to a goal using a heuristic to guide exploration. On occupancy grids it balances travelled distance and heuristic distance; common failure modes include inadmissible heuristics, grid resolution artefacts, lack of dynamic-obstacle handling and no path smoothing for real robot controllers.
A proposed use-case is a lightweight planner for mobile-robot prototypes in simulation: compute collision-free routes on a discrete occupancy map and export the waypoint sequence to a controller. In real deployments keep a human or safety stack in charge and test in simulation before on-robot runs.
Represent the world as an occupancy grid with start and goal markers, and check obstacle cells are correctly annotated.
Implement the frontier (priority queue), cost bookkeeping and a heuristic to guide node expansion while avoiding blocked cells.
Reconstruct the waypoint sequence from came_from, measure path length, and visualise the route on the grid.
Replace the toy grid with simulator traces or sensor-derived maps, add dynamic-obstacle handling, smoothing and a control interface.
The supplied starter implements A* on a small hard-coded 4×5 grid: it locates 'S' and 'G', uses a Manhattan heuristic, explores four-connected neighbours avoiding '#' obstacles, stores costs and came_from, then reconstructs and prints the planned path and its length.
while frontier:
_, current = heapq.heappop(frontier)
if current == goal:
break
for nxt in neighbors(current):
new_cost = cost_so_far[current] + 1
if nxt not in cost_so_far or new_cost < cost_so_far[nxt]:
cost_so_far[nxt] = new_cost
priority = new_cost + heuristic(nxt, goal)
heapq.heappush(frontier, (priority, nxt))The code is a minimal discrete-grid A* demonstration: it uses a tiny hard-coded map, only four-connected moves, a simple Manhattan heuristic, and prints a static path. It lacks continuous-space planning, dynamic-obstacle handling, cost maps, path smoothing, ROS/simulator integration and sensor input.
Proposed extension: feed occupancy grids from a simulator or SLAM output, add path smoothing and waypoint timing, and expose the planner through a ROS/HTTP API for a controller to consume.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.