Two legs good

The cyborgs of popular science fiction always seem to posses a quality that is missing from the robots employed by humans today. It is a quality that many people take for granted but is fundamental to the next phase in robot evolution.

That missing link is the ability to walk and Honda Motor Company and the Sony Corporation have recently announced the development of their new, walking humanoid robots. At long last, these robots look as if they are to be unshackled from the wheels of their predecessors to make full, bipedal mobility a reality.

Sony’s machine, a small biped walking robot named SDR-3X, has been developed as a medium for entertainment whilst Honda’s ASIMO is anticipated to perform a more functional role.

‘With this development of a two-legged humanoid robot that can walk, Honda hopes to create a partner for people, a new kind of robot with a positive function in society,’ said Hiroyuki Yoshino, president and CEO of Honda Motor Company.

What both robots have in common, however, is their ability to accurately replicate the walking movements of their human counterparts.

Honda’s basic research and development in humanoid robotics began in 1986. A decade later, Honda’s prototype robot P2 made its debut, followed by the more advanced P3 in 1997.

ASIMO – which stands for Advanced Step in Innovative Mobility – is a further evolved version of the P3 and Honda’s new robotic walking technology adds a sophisticated ‘predicted movement control’ feature to the walking control technology of earlier Honda robots.

As a result, ASIMO is said to walk more smoothly, more flexibly, and more naturally, with instant response to sudden movements. The range of movement of its arms has also been significantly increased, while a new portable controller enables easier operation.

Honda research determined the ideal robot height to be between 120cm and the height of an average adult, a size that allows the robot to perform basic tasks such as operating light switches and doorknobs.

ASIMO was also made much more compact and lightweight by redesigning its skeletal frame, reducing the frames wall thickness and specially designing the control unit.

A flexible walking control and button operation – for gestures and hand movements – can be carried out from either a workstation or a handy portable controller.

Sony’s SDR-3X can perform basic movements such as walking and changing direction, as well as getting up, balancing on one leg, kicking a ball and dancing due to the synchronised movements of its 24 joints.

The biped walking motion of the SDR-3X is realised by application of OPEN-R architecture – which is used in Sony’s other entertainment robot, AIBO – three types of actuator with different joint sizes and power outputs, and ‘Whole Body Co-ordinated Dynamic Control’.

Sony says that these modules can be easily changed and adapted to enable a robot to perform a variety of new applications.

By combining these three basic components into one device, high power output can be obtained from small, lightweight actuators.

To enable stable walking movement, the Zero Moment Point (where the combined force of both the inertia and body weight meet) must be judged against whether balance is possible on the surface that is being walked upon.

The SDR-3X is said to use two RISC processors for thinking and motion control. Information gathered from a CCD camera, microphone, posture sensors and touch sensors on the bottom of the feet are then processed to synchronise movements of the body joints.

Based on the OPEN-R architecture, Sony has said it will continue to develop basic and applied technologies to explore new possibilities for entertainment robots.

The SDR-3X will be shown at ROBODEX 2000, the world’s first exhibition of ‘Robots as Partner’, from Thursday November 24 for three days until November 26 at Pacifico Yokohama.

More on the web at: and