They never tire, rarely make mistakes, and don't take many vacations. But if a part is misaligned, or a box is out of position, or there's something else not right in the robot's work cell, the robot can crash, damaging a tool or end effector, as well as the robot. This can also happen when operators "train" a robot, programming it though the moves it will be expected to perform. To prevent such crashes, which cost money in equipment and downtime, ATI Industrial Automation, Apex, N.C. (, has developed a Collision Sensor. Operators adjust the sensor, which mounts on the robotic arm, to support typical loads seen by the arm in all directions, as well as angular, compression, and torsional. If the arm then hits an obstruction and exceeds the preset limits, the sensor absorbs the force of the impact through a pneumatic chamber. The energy is then redirected and used to reset the robotic arm to within 0.001 in. of its original position.