Fault tolerance measurement using a six-axis force/torque sensing system with redundancy

Force sensors are a useful tool for robot adapting to human environments. However, these sensors are rarely used for commercial machines requiring safety since it is difficult to eliminate the possibility of failure. Although fault tolerance is an important issue, no critical method for general force measurement is proposed in the past. Hence, this paper proposes a fault tolerance measurement method using sensing devices with redundancy. The proposed method accomplishes both: fault detection without additional sensors; and force estimation during fault period. Furthermore, the fault detection handles many kinds of faults such as disconnection of wires, peeling of strain gauge, and so on. The validity of the proposed method is verified through some simulations and experiments.