Intelligent Gripper Research Articles

Design and Developmental Metrics of a ‘Skin-Like’ Multi-Input Quasi-Compliant Robotic Gripper Sensor Using Tactile Matrix

Slip-resistant robust grasping of objects during remote manipulation remains one of the major open issues in robotics. Finer measurement of tangential force and slippage need to be considered for the task planning and control of robotic gripper in operation. Design and development of such a multi-sensory tactile array is reported in this paper, which is aimed for direct use in an instrumented jaw intelligent robot gripper for potentially hazardous radioactive environments. A new design has been reported in the paper, wherein sensing members of the prototype follow a combination of beam (bending) and truss-type (axial deformation) behavior under external loadings. Various characteristics of the sensor, viz. condition number, static and dynamic stiffness, sensitivity and repeatability have been evaluated, based on the results from field trials of the prototype. Besides the comparatively larger prototype, a miniaturized version of the sensor has also been developed and tested for object grasping in real-time.

ダイナミックダンパで指を制振させたグリッパの基礎研究

ダイナミックダンパで指を制振させたグリッパの特徴をまとめると次のようになる.(1) グリッパの指を (振動子=吸振ばね=把握指=支持ばね) のように2自由度振動系で構成し, 把握指内部で偏心荷重を回転させて周期的強制力を発生させ, この偏心荷重の回転角度と位相角度差を制御して把握指を制振させる.(2) 制振させた把握指の間で物体を把握し, 両指に取り付けた振動子の振幅がゼロになるように把握力を調節したとき, その時の把握力が物体を滑り落とさず, かつ, 握り過ぎでない最適な力になる.(3) 重さと摩擦係数が未知な物体やそれらが変動する物体に対して初期把握動作と把握修正動作を行うと, 物体を常に最適な力で, かつ, 制振させた状態で把握することができる.

Mechatronic design for industrial grippers

A mechatronic design concept for industrial grippers is presented. A specific method for process and workpiece analysis in the preliminary design phase is proposed. The design concept presented is based on experiments in an intelligent gripper research project where different smart grippers were designed and constructed. Two pilot gripper designs are described.

A Method for Considering Safety and Reliability in Automation Design

In order to produce safe and reliable products at reasonable cost designers are advised to identify the fundamental weaknesses during the earliest possible design phase. The complexity of the functions that automated machine systems are required to fulfill, however, makes it difficult to follow this recommendation. An overall model that clearly specifies the system functions is needed. From the conceptual design phase the designer knows what functions must be fulfilled. By introducing appropriate tools the system’s function structure can be established and used in checking the functions and their relationships.The paper presents the application of Structured Analysis and Structured Design method for Real Time Systems (SA/SD) in specifying and modeling the function structure so that safety and reliability aspects can be systematically considered. The analysis of the established structure performed by using Hazard and Operability Study (HAZOP) is also presented. The method described has been applied to an intelligent gripper of a robot.

Order-picking industrial robot

SUMMARYOrder-picking, i.e. arranging work-pieces of different types on a pallet, which is nowadays often carried out manually, will in future be more and more automated for economic reasons. The industrial robot in combination with an intelligent gripper, a supporting palletizing and order-picking software and a suitably designed periphery will permit fully automated order-picking. The Fraunhofer-Institute for Manufacturing Engineering and Automation (F.R.G.) has developed such a system which takes advantage of the arrangement of the work-pieces in the compartment stack and simultaneously grips the work-pieces that are then arranged in a pattern on a pallet.

The application of servo-pneumatic drives for flexible mechanical handling techniques

The present article describes the possibilities of pneumatic drives for fast analog valves and intelligent control system applications. Firstly, the necessary components - valves and actuators - are described. In particular rodless cylinders and optimized motors are discussed. Then design and performance of servo-pneumatic cylinder and rotational drives are presented by means of examples tested under practical service conditions. This shows that the combination of servo-pneumatic components and intelligent microelectronic controllers leads to an up to now unknown system behaviour in the field of pneumatics. Finally, practical examples of the field of robotics are introduced, comprising multi-axle robots built up from individual CNC axles. Moreover, an intelligent gripper with integrated slip sensors is described. As a whole, the great opportunities offered by the application of servo-pneumatics are presented.