Pre-Contact Sensor Based Collision Avoidance Manipulator

In industrial environments where humans and robot manipulators co-exist, it is always a risk that humans get injured while operating alongside robot manipulators in its workspace. In fact, this kind of accidents do occur and in some cases, results in fatalities. Reasons include the negligence of the safety procedures from the human worker or any form of carelessness when the human operator is inside the manipulator’s workspace. Industrial robots are rigid, performance-based machines, but can be equipped with sensors and algorithms to accommodate human presence in the work envelop. The objective of this paper is to propose a pre-contact sensor-based collision avoidance manipulator that adjusts its motion when a human presence is detected by using proximity sensors placed at different locations of the manipulator. The system is then analyzed in terms of sensor positioning and direction of the approaching human. Results indicate that by using ultrasonic sensors and new reference trajectory, the robot is able to detect the approaching motion of the human and decide on the alternative path, if necessary.