In this paper, a safety related parts (SRP) for a double-motor driving method where two motors corporately drive is proposed, which is possible to detect a driving system fault by using a corporate control feature of the driving method. Result of FTA, it was revealed that a fault of the driving system appeared as an abnormal of an output driving signal. Based on the result, we designed an output-monitoring type SRP that compared two driving signals from each motor driving control system and, finally, generated a monitoring signal representing the state of the driving system. The proposed SRP is composed only of hardware, a low pass filter (LPF), a differentiator, and a window comparator, and is independent from a motion control system part. Experiments simulating four fault modes in the FTA were conducted to confirm the validity of the SRP. It was confirmed that the SRP was normally operated and the monitoring signal shifted to a Low level when a fault occurred in each fault mode.

In this paper, we discuss the development of sprawling-type quadruped robot named “TITAN-XIII”. We developed an experimental quadruped robot especially designed for dynamic walking. Unlike dog-like robots, the developed robot looks like a four-legged spider. As a dynamic walking experiment robot, we designed it focusing on the three basic concepts: lightweight, wide range of motion and ease of maintenance. To achieve these goals, we introduce a wire-driven mechanism using a synthetic fiber rope to transmit power to each axis making use of this wire-driven mechanism, we can locate the motors at the base of the leg, reducing its inertia. Additionally, each part of the robot is unitized, and can be easily disassembled. The developed robot was tested and it was confirmed that the robot can perform dynamic walking at 1.38 m/s with cost of transport 1.76.