Integrated Grasping Controller Leveraging Optical Proximity Sensors for Simultaneous Contact, Impact Reduction, and Force Control

TL;DR

This paper introduces a novel control framework that enables robots to grasp unknown objects effectively by simultaneously achieving contact, impact reduction, and force control using optical proximity sensors and a comprehensive impedance control approach.

Contribution

It proposes a new virtual dynamics concept within multiple impedance control to enable simultaneous contact, impact reduction, and force control without switching control laws.

Findings

Successful implementation of simultaneous contact and impact reduction.

Effective force control during grasping of unknown objects.

Enhanced delicate grasping capabilities demonstrated.

Abstract

Grasping an unknown object is difficult for robot hands. When the characteristics of the object are unknown, knowing how to plan the speed at and width to which the fingers are narrowed is difficult. In this paper, we propose a method to realize the three functions of simultaneous finger contact, impact reduction, and contact force control, which enable effective grasping of an unknown object. We accomplish this by using a control framework called multiple impedance control, which was proposed in a previous study. The advantage of this control is that multiple functions can be realized without switching control laws. The previous study achieved two functions, impact reduction and contact force control, with a two layers of impedance control which was applied independently to individual fingers. In this paper, a new idea of virtual dynamics that treats multiple fingers comprehensively is introduced, which enables the function of simultaneous contact without compromising the other two functions. This research provides a method to achieve delicate grasping by using proximity sensors. For the effectiveness of the proposed method, please refer to https://youtu.be/q0OrJBal4yA.