Material recognition of objects by using ultrasonic velocities in intelligent robotics

Advanced robotic techniques are required for autonomous systems to accomplish goals without human intervention. One of the important tasks of robots is object recognition. Although image processing techniques has been developed for distinguishing different objects, it is not possible to detect the object materials or distinguish between objects with the same color or form. This paper proposes an ultrasonic model to detect objects made of different materials even with the same appearances. Ultrasonic velocities, longitudinal and transverse velocities, are a significant parameter which can be used for material characterizations. Different materials have different elastic modulus; and velocity of longitudinal and transverse ultrasonic waves is related to the modulus of materials. So, the determination of longitudinal and transverse wave velocities in an isotropic material makes it possible to detect object materials. In this study, Ultrasonic Probes are mounted in the robot grasp. Probes send ultrasonic wave, longitudinal and transverse wave, to the samples. Then, measured ultrasonic velocities are compared with standard ones to detect objects materials. The results of experiments are very promising, and the designed robot is able to detect objects made of different materials with high accuracy