Robot force sensor interacting with environments

The authors study the impact effect on a robotic system with a force-sensing device installed between the end-effector and the end of the robot. It is shown that physical contact of a robot with environments causes abrupt changes of velocity and force to the end-effector and the force sensor, respectively. The dynamic behavior of the force sensor following the impact is studied. Theoretical analysis and experiments show that the sensor generates a low-to-high transition signal corresponding to an impact, which can be used to identify the contact. To utilize this signal, an electronic switch is designed. The signal triggers the switch, which in turn interrupts the control computer. The control computer can then stop the robot motion immediately after an impact occurs. As a result, damage to, or malfunction of, the robotic system following the impact can be avoided. Experimental results show that the proposed switching mechanism works effectively