Atsuo Takanishi

Humanoid Robots in Waseda University—Hadaly-2 and WABIAN

This paper describes two humanoid robots developed in the Humanoid Robotics Institute, Waseda University. Hadaly-2 is intended to realize information interaction with humans by integrating environmental recognition with vision, conversation capability (voice recognition, voice synthesis), and gesture behaviors. It also possesses physical interaction functions for direct contact with humans and behaviors that are gentle and safe for humans. WABIAN is a robot with a complete human configuration that is capable of walking on two legs and carrying things as with humans. Furthermore, it has functions for information interactions suite for uses at home.

Quantification of masticatory efficiency with a mastication robot

This paper describes the quantification of masticatory efficiency by using a mastication robot that was developed as a mechanical simulator of human masticatory jaw motion on the basis of dental robotics. The masticatory efficiency is evaluated on the basis of human mastication and the quantification of masticatory efficiency is studied experimentally. In this paper, the authors use the sifting test to quantify efficiency. The results of chewing experiments with robot by comparing the differences in chewing motion between clenching and grinding showed that the masticatory efficiency of the latter was higher than that of the former.

A biologically inspired CPG-ZMP control system for the real-time balance of a single-legged belly dancing robot

Recently, a few researchers have started to realize that in order for humanoid robots to move more naturally, it is necessary for them to incorporate a flexible spine in their robots. So far, nobody has come out with a solution which allows their spine robots to maintain balance in real-time. This paper presents a biologically inspired, hybrid CPG-ZMP controller for a single-legged, flexible spine belly dancing robot. Using only two control parameters, our robot can generate rhythmic and wave-like spine motions through the CPG component. By monitoring the torque at the robots ankle, the ZMP component allows the robot to maintain balance in real-time. Unlike traditional ZMP-based controllers, no modeling of the robots dynamics or explicit computations of the zero moment point are required. The resultant robots motions emerge automatically in real-time through dynamic interactions between the robot, its neural network and the environment. Experimental results indicate that our controller has the potential to be applied to a new generation of flexible spine, biped walking humanoid robots.

FROM LAMPREY TO HUMANOID: THE DESIGN AND CONTROL OF A FLEXIBLE SPINE BELLY DANCING HUMANOID ROBOT WITH INSPIRATION FROM BIOLOGY

Research on humanoid robotics has up to now been focused on the control of manipulators and walking machines. The contributions of body torso torwards daily activities have been neglected. To address this deficient area of humanoid robotics research, we developed a unique flexible spine biped humanoid robot. Inspired by the rhythmic and wave-like motions commonly seen in swimming lamprey and in belly dancing, we investigated the possibility of controlling the spine of our robot using the lamprey central pattern generator (CPG). Experimental results show that our robot is capable of mimicing both basic and complex spine motions with fewer actuators than the human spine and using only three input parameters (global and extra excitations from the brainstem, plane of actions). Our work suggests that the CPG is a suitable controller for humanoid spine motions because it can control a high degree of freedom mechanical spine with minimized control parameters. No complex computations of spine trajectories are involved. Furthermore, since our robot can move its upper body dynamically while standing and without external supports, it may be used as a prototype for the next generation of humanoid robots.

Collision-tolerant control algorithm for mobile manipulator with viscoelastic passive trunk

We have proposed the collision-tolerant mobile manipulator equipped with a passive trunk (i.e., supporting part). In collision experiments with unknown environments, results show that this mechanism is suitable for the suppression of contact forces which is an important issue for human-robot collaborations. The trunk with mechanical elements such as springs and dampers is passively deformed to deal with physical contacts, while the mobile platform moves around on the horizontal plane in response to friction between the platform and the ground. The end-effector of the manipulator, however, is difficult to track a desired task due to the deformation of the compliant trunk and the mobility of the platform. In order to solve the problem, the desired joint configurations of the manipulator are directly calculated according to the movement of the trunk and the platform, and a feedback control scheme is employed.

Collision force suppression by human friendly robots with passively movable base

Presents the human safety mechanisms of a human friendly robot (HFR) capable of coexisting with human beings. In order to realize human safety, the HFR is required to be composed of an elastic material-covered manipulator and a passive viscoelastic trunk mounted on a passively movable base like a humans structure. During an expected or unexpected collision/contact between the HFR and its environment, the produced collision/contact forces are extremely attenuated by the combination motion of the passive viscoelastic trunk and passively movable base. The collision-tolerant control algorithm has been developed for the end-effector of the HFR to maintain its desired task during the expected or unexpected collision. Results of collision experiments show that the compliant trunk and movable base are effective mechanisms of suppressing collision forces, and the control algorithm is an effective method of positioning the end-effector.

BIOMECHANICAL ASPECT OF A MASTICATION ROBOT

This paper describes a biomechanical aspect of a mastication robot, and Dental Robotics as a novel field between robotics and dental research. Since 1986 the authors have been developing the WJ (Waseda Jaws) series mastication robots on the basis of dental facts. The characteristics of mastication robots’ are that these robots have similar structures with human. By using this robot we will be able to clarify and construct the quantitative engineering masticatory model for the human mastication.