Five-Fingered Haptic Interface Robot: HIRO III

Abstract

This paper presents the design and characteristics of a five-fingered haptic interface robot named HIRO III. The aim of the development of HIRO III is to provide a high-precision three-directional force at the five human fingertips. HIRO III consists of a 15-degrees-of-freedom (DOF) haptic hand, a 6-DOF interface arm, and a control system. The haptic interface, which consists of a robot arm and hand, can be used in a large workspace and can provide multipoint contact between the user and a virtual environment. However, the following problems peculiar to a multi-DOF robot have arisen: a large amount of friction, a backlash, and the presence of many wires for many motors and sensors. To solve these problems, a new mechanism and a wire-saving control system have been designed and developed. Furthermore, several experiments have been carried out to investigate the performance of HIRO III. These results show the high-precision force display and great potential of HIRO III.

Force control and nonlinear master-slave force profile to manage an admittance type multi-fingered haptic user interface

“…The Haptic User Interface's Finger (HUIF) developed in this research is of similar kinematic form as that of most industrial elbow manipulators [18] and the HIROIII [2]. That is to say, it essentially has a two DOF universal joint at its base and a DOF revolute joint, which is parallel to one of the universal joint's DOF, between its two links.…”

“…The developed force controller will appropriately utilize the general n-link manipulator dynamic equation as shown in equation (2). In equation (2) …”

“…The force control system candidates considered for this system included the Nonlinear Proportional Derivative NPD technique [20], computed torque [21], and explicit force controllers [2][7] [8]. These systems were generally developed to control a manipulator's downward force on a fixed surface which employs certain simplifications compared to the device presented in this research where force will be controlled in all three directions during free translation and interaction.…”

“…In general, HHUIs and general haptic devices consist of two types of structures, these include impedance-type [3] and admittance-type [2] [5]. The impedance-type devices, which are much more predominant, implement backdrivable actuators and position sensing to communicate a force back to the user (impedance control [9]).…”

“…The admittance-type devices can be much more compact with the same strength capacities as that of impedance-type devices due to their geared or otherwise nonlinear strong actuators. However, these devices are difficult to backdrive and require force sensors as inputs to control the device's position/velocity (admittance control [5]), or force (force control [2][6] [7][8]). Although both structures have been implemented in HHUIs, each one has had to develop various methods for accounting for the associated shortcomings.…”