We can do anything from standing to running eggs – ASPINA's technology solutions

A 15th-century Italian explorer Christopher Columbus once stood an egg on its tip to demonstrate his achievement of voyaging beyond the Atlantic Ocean. "Something as difficult as standing an egg on its end can nevertheless be achieved with the boldness to rise to a challenge, new ideas and sufficient capability." More than five centuries later, ASPINA has set out to surpass this story by giving standing eggs the capability to move around.

The Plegg maintains its balance by detecting its tilt using built-in sensors and controlling the two motors driving its wheels accordingly. ASPINA developed the Plegg as an inverted pendulum that gives the robot smooth running and still standing by repeating balance control in close intervals.

An "inverted pendulum" is a control system that keeps an object with a high center of gravity standing and when in motion.The inverted pendulum usually wobbles an object shaped like an egg backward and forward while standing it on two wheels. ASPINA's developed inverted pendulum controls the object as if it was standing still.

Building this inverted pendulum system required not only control of motor rotation but fully synchronized positioning of the two wheel shafts that are connected to two brushless DC (BLDC) motors with current vector control by a single microcomputer, and also required tilt sensing using a three-axis accelerometer and three-axis angular velocity sensor. To achieve this, ASPINA drew on the expertise we have built up in areas like motor control as well as in the use of torque control to get motors to respond precisely to changes in tilt.

To enable Pleggs to move around a defined area, ASPINA developed a new system with a host machine that receives position information from the Plegg wirelessly and sends back instructions to the Plegg. The first iteration of the system mounted a fisheye camera on top of the Plegg and used the camera to determine its position by detecting position markers attached on the area wall. The problem with this was that, because the color images acquired by the fisheye camera also contained other light sources such as fluorescent lighting, it proved difficult to distinguish the markers from those disturbing lights. We made special modifications on the camera and the position markers to try to prevent from the disturbance.

ASPINA has built up more than 50 years of experience in the business of developing and manufacturing not only electric motors, but also optical drives and printers which work with motors, and more recently, industrial high-speed cameras and assistive technology products.

Through its involvement in this business, ASPINA has also acquired a diverse portfolio of technologies that extends beyond electric motors to include image & video processing, robotic control and wireless communication. The company has also built up expertise and a workforce skilled in product design. This expertise extends from exterior design and mechanical design to the design of hardware for power management and data processing circuits, as well as firmware and other software design.

What ASPINA hopes to achieve by showing off the Plegg to trade show visitors and others is to light a fire under ideas that may already have been lurking in the backs of their minds, thereby encouraging the visitors to develop their new products.

In fact, one of the corporate visitors to a trade show, on seeing how the Pleggs moved, inquired whether the same method could also be applied to the undercarriage used for moving robot bodies manufactured by his own company. While the Plegg was a small robot made for demonstration purposes and could not be used in its current form, ASPINA successfully produced a sample undercarriage unit suited to the customer's needs by using the circuit board built for the Plegg to drive two motors.