HMDP: A New Protocol for Motion Pattern Generation Towards Behavior Abstraction

Abstract

The control of more than 20 degrees of freedom in real-time is one challenge of humanoid robotics. The control architecture of an autonomous humanoid robot often consists of two parts, namely a real-time part that has direct access to the motors or RC servos, and a non-real-time part, that controls the higher-level behaviors and sensory information processing such as vision and touch. As a result motion patterns are developed separately from the other parts of the robots behavior. In research, particularly when including developmental processes, it is often necessary that the design or the evolution of motion patterns is integrated in the overall development of the robot's behavior. This is indeed one of the main principles of the embodied intelligence paradigm. The main aim of this work is to define a flexible way of describing motion patterns that can be passed to the motion controller which in turn executes them in real-time. As a result, the Harmonic Motion Description Protocol (HMDP) is presented. It allows the motions to be described as vectors of coefficients of harmonic motion splines. The motion splines are expressed as human-readable ASCII strings that can be passed as a motion stream. Flexibility is achieved by implementing the principle of superposition of several motion patterns. In this way also closed loop control is achievable in principle. Moreover, the HMDP can be implemented into the (deleted for blind review) project of the 3D soccer simulation league as a standard way to communicate motion patterns between the agent and the simulation interface and/or real humanoid robots.

Teaching by touching: An intuitive method for development of humanoid robot motions

“…In the current implementation a simple linear interpolation is used, but the software has been designed to easily permit the use of more sophisticated interpolations, for instance the method used by [16]. While the robot is performing a motion, the joint positions are acquired using the potentiometers present in each of the servomotors, while the overall orientation of the robot is captured using a Motion Analysis Corp. capture system 2 .…”

Neural Networks and Continuous Time

“…For instance, once switching on a robot, i. e. change one input unit from 0 to 1, the periodic behavior should hold on, until the input unit is switched off again (cf. [16]). Therefore, we will introduce units, that oscillate, i. e., whose input may be a fixed value, but whose output yields a sinusoid (see Sect.…”

Intuitive Humanoid Motion Generation Joining User-Defined Key-Frames and Automatic Learning

“…As easily observable in all these examples, this kind of interfaces usually presents one slider for each of the joints, which allows to choose the rotation angle assumed by the servomotor at the frame being edited. Some improvements were proposed, for instance [5] introduced an interface where the motion is represented by Fourier coefficients calculated from control points provided by the user and [6] introduced a system by which the user develops movements by intuitively pushing the robot parts instead of acting on sliders.…”