Grip forces and load forces in handovers

Abstract

In this study, we investigate and characterize haptic interaction in human-to-human handovers and identify key features that facilitate safe and efficient object transfer. Eighteen participants worked in pairs and transferred weighted objects to each other while we measured their grip forces and load forces. Our data show that during object transfer, both the giver and receiver employ a similar strategy for controlling their grip forces in response to changes in load forces. In addition, an implicit social contract appears to exist in which the giver is responsible for ensuring object safety in the handover and the receiver is responsible for maintaining the efficiency of the handover. Compared with prior studies, our analysis of experimental data show that there are important differences between the strategies used by humans for both picking up/placing objects on table and that used for handing over objects, indicating the need for specific robot handover strategies as well. The results of this study will be used to develop a controller for enabling robots to perform object handovers with humans safely, efficiently, and intuitively.

Handover Control for Human-Robot and Robot-Robot Collaboration

“…The human releases its grasp and the robot withstands all the weight as shown in Figure 8-top. The duration between the end of the sharing phase (when the robot gives the cue) and the end of the object passing (when all the load is withstood by the robot) is about 400 ms, that is in line with the passing time observed in Human-to-Human handovers (Mason and MacKenzie, 2005;Chan et al, 2012;Endo et al, 2012). During the passing phase we observe two peaks in the velocity profile, a first smaller peak at about t 7.1 s corresponds to the robot cue, then, at about t 7.5 s there is another peak that corresponds to the giver release.…”

“…The giver decreases its grip force, while the receiver increases it until the load is transferred. Another relevant aspect, highlighted by Chan et al (2012), consists in the post-unloading phase, when the giver still applies a grasping force even though its sensed load is almost zero. This means that the giver is the agent responsible of the object safety during the passing.…”

Towards Seamless Human-Robot Handovers

“…Then the giver will retract his arm signaling the same, thus ending this phase and handover interaction. (Chan et al, 2012) found a linear relationship between grip force and load force except when either actor is supporting very little of the object load. Analysis of these grip forces suggests the giver is responsible for the well being of the object during the transfer, while the receiver is responsible for the timing of the transfer.…”

“…The social modification of pickand-place movements is demonstrated in (Becchio, Sartori, & Castiello, 2010) comparing velocity profiles for placing an object on a container versus another person's palm. (Chan, Parker, Van der Loos, & Croft, 2012) investigated the grip forces applied on an object while it is transferred between two humans during a handover. Based on the observed patterns, they proposed a model for a similar handover behavior for robots.…”

Ευσταθής Λαβή Και Μεταβίβαση Φορτίου Αντικειμένου Από Ρομπότ Σε Άνθρωπο

“…Εκτός από τη φάση προσέγγισης, η ευχέρεια της απτικής αλληλεπίδρασης μεταξύ του ανθρώπου και του ρομπότ είναι πολύ σημαντική για τη φυσική ένταξη του ρομπότ στο ανθρώπινο περιβάλλον. Προς αυτό τον σκοπό, έχουν γίνει αρκετές μελέτες σε ανθρώπους οι οποίες αναλύουν τη διαδικασία και τα χαρακτηριστικά που είναι απαραίτητα για μια επιτυχημένη μεταβίβαση αντικειμένου [94,117,118]. Η υψηλή ευαισθησία των ανθρώπων στο συγχρονισμό δείχνει την ανάγκη για ανάπτυξη στρατηγικών ελέγχου για την παράδοση αντικειμένων που να εμπνέονται από τους ανθρώπους.…”