MIRMI researchers turn robots into skilled waiters
Researchers at the Munich Institute of Robotics and Machine intelligence (MIRMI) at the Technical University of Munich (TUM) have developed a model that enables a robot to serve tea and coffee faster and more safely than humans – with no sloshing.
The mathematics behind the pendulum used in the concept is more than 300 years old. The team simply fed the robot with algebraic formulae based on the mathematics of a Moroccan tea tray that applies the principle of a spherical pendulum. They embedded the dynamics of the spherical pendulum into the robot’s control software such that the robot’s movements are limited by the basic principles of geometry. The team also integrated the correct angles, speeds and accelerations into the model.
The science of ‘slosh-free movement’ is a complex field. “Most approaches have focused mainly on limiting acceleration to keep the sloshing of liquids under control, or they have worked with fluid dynamics to calculate how these substances behave in order to predict the trajectories,” explained Dr Luis Figueredo, senior scientist in the team. “That takes at least a few minutes, if not hours, and the result is still uncertain.”
As a practical application, the scientists initially envision innovative robotic support for elderly people and those requiring nursing care. “But industries involved in the transport of materials posing biological and chemical hazards would probably be interested in a solution like this, too,” said Figueredo.
Safety remains a critical point: a robot should ideally be capable of recognising dangerous situations. “For that we need better perception,” said Figueredo. Sensors would then enable the machine not only to recognise people, but also to predict their movements. That is the only way to completely rule out collisions with the robot.
So far the robot is working with ‘tactile sensors’ as a safety mechanism. In the current slosh-free mode, the robot arm instantly retracts when it senses the collision, but also keeps the liquid safe.
Visit the MIRMI website for more information
