61,938 research outputs found
Unifying Skill-Based Programming and Programming by Demonstration through Ontologies
Smart manufacturing requires easily reconfigurable robotic systems to increase the flexibility in presence of market uncertainties by
reducing the set-up times for new tasks. One enabler of fast reconfigurability is given by intuitive robot programming methods. On
the one hand, offline skill-based programming (OSP) allows the definition of new tasks by sequencing pre-defined, parameterizable
building blocks termed as skills in a graphical user interface. On the other hand, programming by demonstration (PbD) is a
well known technique that uses kinesthetic teaching for intuitive robot programming, where this work presents an approach to
automatically recognize skills from the human demonstration and parameterize them using the recorded data. The approach further
unifies both programming modes of OSP and PbD with the help of an ontological knowledge base and empowers the end user to
choose the preferred mode for each phase of the task. In the experiments, we evaluate two scenarios with different sequences of
programming modes being selected by the user to define a task. In each scenario, skills are recognized by a data-driven classifier
and automatically parameterized from the recorded data. The fully defined tasks consist of both manually added and automatically
recognized skills and are executed in the context of a realistic industrial assembly environment
Robot training using system identification
This paper focuses on developing a formal, theory-based design methodology to generate transparent robot control programs using mathematical functions. The research finds its theoretical roots in robot training and system identification techniques such as Armax (Auto-Regressive Moving Average models with eXogenous inputs) and Narmax (Non-linear Armax). These techniques produce linear and non-linear polynomial functions that model the relationship between a robot’s sensor perception and motor response.
The main benefits of the proposed design methodology, compared to the traditional robot programming techniques are: (i) It is a fast and efficient way of generating robot control code, (ii) The generated robot control programs are transparent mathematical functions that can be used to form hypotheses and theoretical analyses of robot behaviour, and (iii) It requires very little explicit knowledge of robot programming where end-users/programmers who do not have any specialised robot programming skills can nevertheless generate task-achieving sensor-motor couplings.
The nature of this research is concerned with obtaining sensor-motor couplings, be it through human demonstration via the robot, direct human demonstration, or other means. The viability of our methodology has been demonstrated by teaching various mobile robots different sensor-motor tasks such as wall following, corridor passing, door traversal and route learning
Learning Human-Robot Collaboration Insights through the Integration of Muscle Activity in Interaction Motion Models
Recent progress in human-robot collaboration makes fast and fluid
interactions possible, even when human observations are partial and occluded.
Methods like Interaction Probabilistic Movement Primitives (ProMP) model human
trajectories through motion capture systems. However, such representation does
not properly model tasks where similar motions handle different objects. Under
current approaches, a robot would not adapt its pose and dynamics for proper
handling. We integrate the use of Electromyography (EMG) into the Interaction
ProMP framework and utilize muscular signals to augment the human observation
representation. The contribution of our paper is increased task discernment
when trajectories are similar but tools are different and require the robot to
adjust its pose for proper handling. Interaction ProMPs are used with an
augmented vector that integrates muscle activity. Augmented time-normalized
trajectories are used in training to learn correlation parameters and robot
motions are predicted by finding the best weight combination and temporal
scaling for a task. Collaborative single task scenarios with similar motions
but different objects were used and compared. For one experiment only joint
angles were recorded, for the other EMG signals were additionally integrated.
Task recognition was computed for both tasks. Observation state vectors with
augmented EMG signals were able to completely identify differences across
tasks, while the baseline method failed every time. Integrating EMG signals
into collaborative tasks significantly increases the ability of the system to
recognize nuances in the tasks that are otherwise imperceptible, up to 74.6% in
our studies. Furthermore, the integration of EMG signals for collaboration also
opens the door to a wide class of human-robot physical interactions based on
haptic communication that has been largely unexploited in the field.Comment: 7 pages, 2 figures, 2 tables. As submitted to Humanoids 201
- …