Assistive robots aim at developing aids to improve the qualities of human’s life with any sort of disabilities issues. It can also be used to enhance independent living, such as helping the elderly. They also are capable of providing mobility to elderly who has trouble getting around. Determination of a collision free path for a robot between start and goal positions through obstacles cluttered in a workspace is central to the design of an autonomous robot path planning. This paper presents an overview of autonomous mobile robot path planning focusing on landmark pattern algorithm that produce an optimal path for a robot to navigate in an indoor environment. To complete the navigation task, the algorithms will read the map of the indoor environment and subsequently attempts to create free paths for the robot to traverse in the indoor environment without colliding with objects and obstacles. To achieve this, various approaches in the design of algorithms used to develop an ideal path planning system for autonomous mobile robots have been proposed by many researchers. Simulation and experimental results from previous research shows that algorithms play an important role to produce an optimal path (short, smooth and robust) for autonomous robot navigation and simultaneously it prove that appropriate algorithms can run fast enough to be used practically without time-consuming problem.

A basic motion planning problem is to produce a continuous motion that connects a start configuration S and a goal configuration G, while avoiding collision with known obstacles. We have algorithms A* and D* etc for path planning. Like all search algorithms, the above algorithms first searches the routes that appear to be most likely to lead towards the goal. A* algorithm chooses the path where the actual cost of the path is less than the estimated cost and D* algorithm finds difficult to choose the shortest path when the number of such paths are two or more than two of same distance.

To overcome the mentioned problems for robotic path planning, here we have an algorithm for robot path planning with sign based system. The main theme of this project is to develop a self-intelligent autonomous robot which can assist in indoor environment to perform various tasks by an algorithm based on a given path. When the robot receives a navigation task by color and pattern techniques, it evaluates RGB colors i.e. red, green and blue. The path is evaluated by blob analysis technique and pattern technique; there are three types of patterns used. Patterns are square, circle and triangle. Robot collects all the data of path probabilities and then compares them to find out the path. One of the major issues to reach the destination successfully is obstacle detection and avoidance. By using ultrasonic sensors robot can easily avoid all the obstacles in the path and move towards the destination point.