PROXIMITY SENSORS FOR ROBOTS

ABSTRACT
In order to perform the task in a satisfactory way the robot must have certain humanlike senses and capabilities. These include vision and hand-eye coordination, touch and hearing. This is achieved by using sensors. The types of sensors used in robotics include vision, voice, tactile, proximity etc. proximity sensors measure the relative distance between the sensors and objects in the robot's environment. This sense keeps a robot from running into things. A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic or electrostatic field, or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominal range or means to report a graduated detection distance. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between sensor and the sensed object. This paper describes the various proximity sensors employed in robots