Toward an Intuitive and Iterative 6D Virtual Guide Programming Framework for Assisted Human–Robot Comanipulation

Abstract

SUMMARY In human–robot comanipulation, virtual guides are an important tool used to assist the human worker as they constrain the movement of the robot to improve the task accuracy and to avoid undesirable effects, such as collisions with the environment. Consequently, the physical effort and cognitive overload are reduced during accomplishment of comanipulative tasks. However, the construction of virtual guides often requires expert knowledge and modeling of the task, which restricts the usefulness of virtual guides to scenarios with fixed constraints. Moreover, few approaches have addressed the implementation of virtual guides enforcing orientation constraints and, when done, these approaches have treated translation and orientation separately, and consequently there is no synchronization of the translational and rotational motions. To overcome these challenges and enhance the programming flexibility of virtual guides, we present a new framework that allows the user to create 6D virtual guides through XSplines which we define as a combination of Akima splines for the translation component and spherical cubic interpolation of quaternions for the orientation component. For complex tasks, the user is able to initially define a 3D virtual guide and then use this assistance in translational motion to concentrate only on defining the orientations along the path. It is also possible for the user to modify a particular point or portion of a guide while being assisted by it. We demonstrate in an industrial scenario that these innovations provide an intuitive solution to extend the use of virtual guides to 6 degrees of freedom and increase the human worker’s comfort during the programming phase of these guides in an assisted human–robot comanipulation context.

Wire Harness Assembly Process Supported by Collaborative Robots: Literature Review and Call for R&D

“…Teleoperation can be very useful when the robot makes rapid movements and is very close to operators. Other methods include specific work areas where the cobot must move, such as in the work of Sánchez Restrepo et al [26], where the workers are near a cobot. Other methods, such as reducing forces or speed, can also be used.…”

“…The paper from Sánchez Restrepo et al [26] offers a methodological solution that could be used in cable tie collocation or spot-taping tasks to avoid collisions with objects in the working environment or with the operator because the areas in which the cobot can move are limited, improving the employees' safety. Another method to enhance the safety of the workers could be including presence sensors to stop or reduce the movement of the cobot.…”

“…Furthermore, the method of Mateus et al [8] could be used to determine at which task, in particular, a cobot could be placed considering its capabilities, complementing the work of Malik and Bilberg [30], and the Gualtieri et al [11] method could tell if this integration of a cobot is possible and necessary from safety, ergonomics, and time performance perspectives. For safety, the method proposed by Sánchez Restrepo et al [26] and Girbes-Juan et al [28] should be considered.…”

“…In the paper of Sánchez Restrepo et al [26] on "Toward an Intuitive and Iterative 6D Virtual Guide Programming Framework for Assisted Human-Robot Comanipulation", they developed a virtual guideline, which is a software tool for offline programming of cobots. It is used to delimitate a cobot movement to avoid collisions between workers or objects in the environment.…”

“…Sánchez Restrepo et al [26] CRI IM This paper proposes an intuitively virtual guide for the easy programming of a robot without the need for an expert/expertise.…”