Exploiting the robot kinematic redundancy for emotion conveyance to humans as a lower priority task

Current approaches do not allow robots to execute a task and simultaneously convey emotions to users using their body motions. This paper explores the capabilities of the Jacobian null space of a humanoid robot to convey emotions. A task priority formulation has been implemented in a Pepper robot which allows the specification of a primary task (waving gesture, transportation of an object, etc.) and exploits the kinematic redundancy of the robot to convey emotions to humans as a lower priority task. The emotions, defined by Mehrabian as points in the pleasure–arousal–dominance space, generate intermediate motion features (jerkiness, activity and gaze) that carry the emotional information. A map from this features to the joints of the robot is presented. A user study has been conducted in which emotional motions have been shown to 30 participants. The results show that happiness and sadness are very well conveyed to the user, calm is moderately well conveyed, and fear is not well conveyed. An analysis on the dependencies between the motion features and the emotions perceived by the participants shows that activity correlates positively with arousal, jerkiness is not perceived by the user, and gaze conveys dominance when activity is low. The results indicate a strong influence of the most energetic motions of the emotional task and point out new directions for further research. Overall, the results show that the null space approach can be regarded as a promising mean to convey emotions as a lower priority task.Postprint (author's final draft

Identification of Consistent Standard Dynamic Parameters of Industrial Robots

International audienceThe dynamics of each link and joint of a robot is characterized by a set of 14 standard dynamic parameters (6 for the inertia matrix, 3 for the centre of mass coordinates, 1 for the mass and 4 for the drive chain inertia and friction). It is known that only a subset of the standard parameters, called the base parameters, are identifiable using the inverse dynamic model and the linear least squares techniques. Moreover, some of the base parameters are poorly identified because they poorly affect the joint torque. Thus they can be eliminated, leading to a new subset of dynamic parameters called the essential parameters. However, the identified values of the base or the essential parameters may be physically inconsistent regarding to the loss of the positive definiteness of the robot inertia matrix. Several methods have been developed in the past to verify the physical consistency of the identified parameters but they are complicated , time consuming and lead to non-optimal parameters. To overcome these drawbacks, a new method calculates a set of optimal standard dynamic parameters which are the closest to a priori consistent dynamic parameters obtained through CAD data given by the robot manufacturers. This is a straightforward method which is based on using the SVD and the Cholesky factorization and the linear least squares techniques. The new procedure is experimentally validated on an industrial 6 degrees of freedom Stäubli TX-40 robot

Dance with me! : child-robot interaction in the wild

This paper presents the results of a singular experiment that has been conducted in a kindergarten in Japan. Four groups of ten children aged 3- to 5-year old interacted freely with the robot Pepper for about 20 min. In the first part of the experiment, the robot introduced itself to the children explaining a few basics. The children were then invited to touch the robot, to dance with it and finally to play with it freely while it was idle. Our experiment shows that regardless of the children’s age, they engage easily with the robot while it was talking and moving, however children of different ages have a different perception of the robot when it is idle. Younger children consider it more as a toy while older children are more likely to attribute a meaning to its idleness

Identification of Flying Humanoids and Humans

Abstract-The mass properties are important to control robot dynamics or study human dynamics. In our previous works, we proposed a method to identify inertial parameters of legged mechanisms from base-link dynamics, using generalized coordinates and external forces information. In this paper, we propose an identification method based on floating-base dynamics, when the system has no external force. Inertial parameters can be identified without force measurement, only from motion data. The method has been tested on two examples; a simple chain consisted of two links and the human body dynamics

Exploring the role of trust and expectations in CRI using in-the-wild studies

Studying interactions of children with humanoid robots in familiar spaces in natural contexts has become a key issue for social robotics. To fill this need, we conducted several Child-Robot Interaction (CRI) events with the Pepper robot in Polish and Japanese kindergartens. In this paper, we explore the role of trust and expectations towards the robot in determining the success of CRI. We present several observations from the video recordings of our CRI events and the transcripts of free-format question-answering sessions with the robot using the Wizard-of-Oz (WOZ) methodology. From these observations, we identify children’s behaviors that indicate trust (or lack thereof) towards the robot, e.g., challenging behavior of a robot or physical interactions with it. We also gather insights into children’s expectations, e.g., verifying expectations as a causal process and an agency or expectations concerning the robot’s relationships, preferences and physical and behavioral capabilities. Based on our experiences, we suggest some guidelines for designing more effective CRI scenarios. Finally, we argue for the effectiveness of in-the-wild methodologies for planning and executing qualitative CRI studies

Modeling and identification of passenger car dynamics using robotics formalism

International audienceThis paper deals with the problem of dynamicmodeling and identification of passenger cars. It presents a new method that is based on robotics techniques for modeling and description of tree-structured multibody systems. This method enables us to systematically obtain the dynamic identification model, which is linear with respect to the dynamic parameters. The estimation of the parameters is carried out using a weighted least squares method. The identification is tested using vehicle dynamics simulation software used by the car manufacturer PSA Peugeot-Citroën in order to define a set of trajectories with good excitation properties and to determine the number of degrees of freedom of the model. The method has then been used to estimate the dynamic parameters of an experimental Peugeot 406, which is equipped with different position, velocity, and force sensors

Editorial: Computational Approaches for Human-Human and Human-Robot Social Interactions

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On the role of trust in child-robot interaction

In child-robot interaction, the element of trust towards the robot is critical. This is particularly important the first time the child meets the robot, as the trust gained during this interaction can play a decisive role in future interactions. We present an in-the-wild study where Polish kindergartners interacted with a Pepper robot. The videos of this study were analyzed for the issues of trust, anthropomorphization, and reaction to malfunction, with the assumption that the last two factors influence the children’s trust towards Pepper. Our results reveal children’s interest in the robot performing tasks specific for humans, highlight the importance of the conversation scenario and the need for an extended library of answers provided by the robot about its abilities or origin and show how children tend to provoke the robot