Milutin Nikolić

Adaptive multimodal interaction with industrial robot

This paper reports a spoken natural language dialogue system that manages the interaction between the user and the industrial robot ABB IRB 140. To the extent that the dialogue system is multimodal, it uses three communication modalities: (i) spoken language (automatic speech recognition and text-to-speech synthesis), (ii) visual recognition of the figures and determination of their positions, and (iii) typed text. To the extent that the dialogue system is adaptive, it takes the verbal and spatial contexts into account in order to adapt its dialogue behavior and to process spontaneously formulated user commands of different syntactic forms without explicit syntactic expectations. The industrial robot is slightly modified and enabled to manipulate over graphical figures, following the instructions of the dialogue system.

Realization of Biped Walking in Unstructured Environment Using Motion Primitives

Effective and efficient motion of humanoid robots in unstructured dynamic environments is a prerequisite for their activity in the living and working environment of humans. Motion in such environments has to be adjusted all the time to suit the current conditions. This paper presents a method for the synthesis and realization of the biped robot motion (walking) composed of simple movements-primitives, because any complex motion can be composed of tied primitives. The primitives are parametrized with the relationship established between the overall motion characteristics and their own parameters. This way, it is possible to achieve online modification at any moment. The proposed solution was tested by the simulation involving a dynamic robot model. The results demonstrate that it is possible to generate a dynamically balanced walk that can be modified online at any moment of its realization.

Human-like Robot MARKO in the Rehabilitation of Children with Cerebral Palsy

Actual research in the field of robot-supported therapy is dominantly oriented on systems for clinical neurorehabilitation of motor disorders and therapy of difficulties related to autism. However, very little attention is dedicated to the functional development of the therapeutic robot, which would be capable of participating, actively and intelligently, in a verbal dialogue of natural language with a patient and therapist. In this paper an approach is presented for incorporating the human-like robot MARKO in the physical therapy for children with cerebral palsy (CP). The mechanical design of the robot MARKO is briefly described and its context aware cognitive system which connects modules for sensorimotor system, speech recognition, speech synthesis and robot vision is presented. The robot is conceived as a child’s playmate, able to manage three-party natural language conversation with a child and a therapist involved. Traditional CP physical therapies are usually repetitive, lengthy and tedious which results in a patient’s lack of interest and disengagement with the therapy. On the other hand, treatment progress and the improvement of the neural functionality are directly proportional to the amount of time spent exercising. The idea is to use the robot to assist doctors in habilitation/rehabilitation of children, with a basic therapeutical role to motivate the children to practice therapy harder and longer. To achieve this, the robot must fulfill several requirements: it must have hardware design which provides sufficient capabilities for demonstration of gross and fine motor skills exercises, it must have appropriate character design to be able to establish affective attachment of the child, and it must be able to communicate with children verbally (speech recognition and synthesis), and non-verbally (facial expressions, gestures).

Walking on Slippery Surfaces: Generalized Task-Prioritization Framework Approach

Like humans, bipedal robots can easily fall on slippery and low-friction surfaces. In order to avoid costly breakdowns, fall avoidance is of major importance. Recently reported generalized task-prioritization framework enables us to impose dynamical inequality constraints on the robot motion, which we used to create quasi-static walk using task prioritization. Created walking is tested on high- and low-friction surfaces and resulting walking patterns are observed.

Biped Walking on Irregular Terrain Using Motion Primitives

Effective and efficient motion of humanoid robots is a prerequisite for their activity in the unstructured environment. It is of great importance to enable the walk on uneven ground surface. This work presents a method for the synthesis and realization of the online modifiable robot walk that is adjustable to the partially unknown configuration of ground surface. Walk is composed of tied simple movements—primitives which are parameterized with established relationship with overall motion parameters. Proposed approach was tested by simulation and it was demonstrated that it is possible to generate a online modifiable dynamically balanced walk. For such walk is tested the ability to adapt to uneven configuration to uneven terrain.

Online Generation of Biped Robot Motion in an Unstructured Environment

In this work is demonstrated the possibility of using primitives to generate complex movements that ensure motion of bipedal humanoid robots in unstructured environments. It is pointed out that for the robot’s motion in an unstructured environment an on-line generation of motion is required. Generation of motion by using primitives represents superposition of simple movements that are easily performed. Simple movements are either reflex or learned synchronous movements of several joints, and each of these movements represents one primitive. Each primitive has its parameters and constraints that are determined on the basis of the movements capable of performing by a human. A set of all primitives represents the data base from which primitives are selected and combined for the purpose of performing a complex movement.

Humanoid Robot Reaching Task Using Support Vector Machine

A novel approach for the realization of the humanoid robot’s reaching task using Support Vector Machine (SVM) is proposed. The main difficulty is how to ensure an appropriate SVM training data set. Control law is firstly devised, and SVM is trained to calculate driving torques according to control law. For purpose of training SVM, sufficiently dense training data set was generated using designed controller. However, dynamic parameters of the system change when grasping is performed, so SVM coefficients were altered in order to adapt to changes that have occurred. In the stage of verification, the target point to be reached by the robot’s hand is assigned. The trained SVM determines the necessary torques in a very efficient way, which has been demonstrated by several simulation examples.

Generating Complex Movements of Humanoid Robots by Using Primitives

The objective of this work is to demonstrate the possibility of using primitives to generate complex movements that ensure motion of bipedal humanoid robots. Primitives represent simple movements that are either reflex or learned. Each primitive has its parameters and constraints that are determined on the basis of the movements capable of performing by a human. The set of all primitives represents the base from which primitives are selected and combined for the purpose of performing the corresponding complex movement. The proof that a correct selection of primitives is made and that the movement is the appropriate one is obtained on the basis of the maintainance of dynamic balance, which is realized by monitoring the ZMP position, as well as based on the pattern of the very movement.

Parameters adaptation of motion primitives for achieving more efficient humanoid walk

This paper deals with the problem of non synchronicity during the on-line realization of humanoid walk synthesized by combining and tying motion primitives. Motion primitives are simple and parameterized movements. For realization of the on-line modifiable walk, relationship is established between the gait characteristics and the pa-rameters of the primitives. The parameters of the primitives for basic walk were determined empirically, so the problem appeared of non synchronization of the primitives that are executed in parallel. In order to reduce the non synchronicity effects, the algorithm for adaptation of the primitive parameters is introduced. The improved parameters of the primitives allowed the realization of a more efficient walk.

Design and fabrication with industrial robot as brick-laying tool and with custom script utilization

This paper presents methodology and implementation of parametric architectural design of bricklaying walls fabricated by industrial robotic arm. As a design tool Grasshopper is used, a visual programming editor that runs within the Rhinoceros 3D CAD application. Grasshopper offers a range of objects for creating parametric models including bricklaying walls. However it lacks the ability of integration with fabrication tools. To overcome this problem, a custom C# script has been developed. As the fabrication tool, the ABB-IRB 140 robotic arm is used. Thus the C# script is written in such a way to obtain the RAPID code for controlling ABB industrial robots. The C# script enabled automated generation of RAPID code in accordance to the Grasshopper generated geometries of walls. The RAPID code is firstly tested in simulation environment, afterwards is used to control the robot to fabricate various types of walls.