LITERATURE SURVEY 1.EFFICIENT PATH PLANNING IN SEMI- FAULT TOLERANT ROBOTICS 2. Caesar robot

EFFICIENT PATH PLANNING IN SEMI- FAULT TOLERANT ROBOTICS  Main task - proper execution of actions based on the set of beliefs  Robot that is able to make decisions in multiple environments  Training of robot using offline maps graceful  Degradation of the sensors in hostile and difficult environments  The goal is to find an optimal path, avoiding maximum collision and increasing the optimization in real-time robotics

ALGORITHM:-  Repeated forward A*  Pass the initial location of the robot and final goal location  Executes the Compute Path algorithm  Backtracks from the goal to agent using tree pointer  Find the shortest path among the path nodes calculated  Moves the agent along the selected path  Five values for each state: g(s), h(s), f(s), tree(s) & search(s)

 Initially, start state pushed into open list  Then removed and moved to closed list  Actions performed on node & f(s) updated  States with greater g(s) into open list  Loop finds next minimum f(s) node  Procedure continues until goal reached

IMPLEMENTATION :-  Software implementation under open-source environment, so Java used  Creates software objects which are encapsulations of data and procedures.  Simulating java code using ECLIPSE SDK  DC motor for driving and servo for steering  Focus – to achieve less weight with elegant design  Aluminium frame work sufficiently strong  Capacity to add new parts  Weight within the figure formed, so easily handled  Size not too small nor large

ADVANTAGES:-  Strong frame work and low cost  Provides smooth drive  Front wheel drive chosen  One DC motor and one servo motor required  Rear wheels are self aligned  Surface of the wheels provide greater grip

DISADVANTAGES:-  Collision avoidance not considered  Multiple agents system scenario not mentioned

Caesar robot  Previous USAR robots and their associated problems  Improvements of the mechanical, communication and sensory systems  To provide development of USAR robots  Include semi-autonomous robots

Mechanical System:-  CAESAR's tracks prevented slippage on smooth surfaces  Flipper arms assisted with climbing over obstacles  Gradual lift of the front or back part  Kevlar and phenolic resin composite body ensured a strong body  Heat reflected by aluminized Kevlar  CAESAR has an overall weight of 56.5 kg

Communication System :-  Use of UHF dedicated frequencies allowed radio signals to be reflected  Robotic Communication Protocol allowed data reliability  Corruption of data prevented  Eggbeater antennas for omni-directional communication  Thermal video transmission possible

Sensory System :-  Thermal camera revealed heated areas  Sonar sensors for object detection  Gas sensors included onboard identifies gas concentration levels  Control unit included GUI with AI  Allows controlling of diff robots, but one at a time  GUI indicates unsafe areas by changing color

 Thus CAESAR robot could provide: 1.Thermal imaging 2.Gas sensing 3.Maneuverability 4.Audio feed 5.Telemetry 6.Thermal shielding 7.Low weight and size