This paper describes the means of tuning-up method of the walking parameters to go up and down stairs for a biped robot with leg mechanisms using Stewart platforms. It has been confirmed that the stroke range of use could be reduced by tuning up the waist yaw trajectory and preset ZMP trajectories for motion pattern generation. By using the developed method, a walking experiment involving movement up and down a stair with the rise of 250 mm and certain walking experiments ascending and descending stairs carrying a human were successfully completed. Through these experiments, the effectiveness of the proposed method was confirmed.

This paper describes the mechanism of biped locomotor, WL-16 (Waseda Leg No. 16), its compliance control method and experiments carrying a human. This robot is developed based on WL-15's basic design using new gimbals' mechanisms with small backlash and new linear actuators dealing with a heavy payload and a wide movable range. Walking experiments carrying a human are successfully completed and the effectiveness of WL-16's mechanism and control method are confirmed.

In this paper, we describe the system design and control of a miniature robotic rat, WR-5, which is intended to interact with laboratory rats. WR-5 can perform rearing, mounting, rotating, and body-grooming actions as naturally as live mature rats because of its multilink structure. Experimental results confirm that WR-5 can stimulate stressing fear in rats by performing a mounting action, which shows remarkable progress when compared with the previous generation of these robots. Additionally, a virtual impedance model-based control method is used to generate both posture and trajectory for WR-5. The results of simulations and following tests with real rats show that WR-5 can adjust its head and body positioning to follow a target rat in real time. The control system simultaneously allows real-time avoidance of moving outside observers during the following test. Additionally, based on interaction with multiple rats, we conclude that the robotic rat shows great promise for manipulation of the sociality of rats.

Biped walking is easily adaptable to rough terrain such as stairs and stony paths, but the walk speed and energy efficiency on the flat ground is not so effective compared with wheeled locomotion. In this paper, we propose a biped robot to be able to walk or wheel according to the ground conditions. For wheeled locomotion, WS-2 (Waseda Shoes -No. 2) is developed which is composed of a DC motor, a spherical caster and two rubber pads on each foot. WS-2 is attached to the feet of WL-16 (Waseda Leg -No. 16) that is the world's first biped-walking robot capable of carrying a human. Also, a path planning for wheeled locomotion is presented. Through hardware experiments, the effectiveness of this foot module is confirmed.