  This paper discusses the development of robot motion generation interface
between a real-time software architecture and a non-real-time robot operating
system. In order for robots to execute intelligent manipulation or navigation,
close integration of high-level perception and low-level control is required.
However, many available open-source perception modules are developed in ROS,
which operates on Linux OS that don't guarantee RT performance. This can lead
to non-deterministic responses and stability problems that can adversely affect
robot control. As a result, many robotic systems devote RTOS for low-level
motion control. Similarly, the humanoid robot platform developed at KAIST,
Hubo, utilizes a custom real-time software framework called PODO. Although PODO
provides easy interface for motion generation, it lacks interface to high-level
frameworks such as ROS. As such, we present a new motion generation interface
between ROS and PODO that enables users to generate motion trajectories through
standard ROS messages while leveraging a real-time motion controller. With the
proposed communication interface, we demonstrate series of manipulator tasks on
the actual wheeled humanoid platform, M-Hubo. The overall communication
interface responsiveness was at most 27 milliseconds.
