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Ch40-I044963.fm Page 189 Tuesday, August 1, 2006 8:21 PM
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SAFETY DESIGN FOR SMALL BIPED-WALKING
HOME-ENTERTAINMENT ROBOT SDR-4XII
Masatsugu Iribe, Tomohisa Moridaira, Tetsuharu Fukushima, Yoshihiro Kuroki

Motion Dynamics Reseach Lab., Information Technologies Labs, Sony Corporation,
6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo, 141-0001, Japan

ABSTRACT

In March 2003, we proposed a small biped-walking home-entertainment robot SDR-4XIT (Sony
Dream Robot -4XTI, a prototype), which was developed for home use and entertainment. As SDR-4XIT
is developed for home use, it is designed to be safe. And the important roles of the safety features de-
th
pend on the functions of newly developed robotic actuator "ISA-4" (Intelligent Servo Actuator 4 ). The
actuator contributes SDR-4XII's motion control and safety management very much. In this paper we
introduce the safety functions which are achieved in the development of SDR-4XI1 and ISA in detail.

KEYWORDS

home-entertainment robot, biped-walking, safety design, motion control, SDR-4XTI, Intelligent Servo
Actuator (TSA)

INTRODUCTION
In March 2003, we proposed a small biped-walking home-entertainment robot SDR-4XII (Sony
Dream Robot -4XII, a prototype), which was developed for home use and entertainment (Kuroki
2003-2). For that purpose, SDR-4XII is designed to be safe, i.e. not to hurt human users, itself, or any
other beings in the environment. The robot has 38 DOF (degrees of freedom) in its joints, and the 22
joints important for its motion control are driven by newly developed robotic actuator ISA-4 (Intelligent
th
Servo Actuator 4 ). The robotic actuator ISA-4 consists of three major parts; a motor which contains
originally designed electromagnetic circuits, high precision gears, and electrical circuits (Fukushima
2004). By this construction, we achieved to develop a compact and high performance robotic actuator.
And in addition, ISA-4 detects unusual situations such as overloads by signals from the sensors both in
its own body and in the SDR-4XII's parts. We achieved important safety features for human user's
safety and the robot's body protection with the ISA-4.
In this paper we introduce the safety features which are achieved in the development of SDR-4XII
and ISA-4, and also describe the methods of the functions in detail.