Anthropomorphic Hand Research Articles

組立作業における意図解析による人間型ハンドロボットへのVR教示(VRとインタフェース1)

組立作業における意図解析による人間型ハンドロボットへのVR教示(VRとインタフェース1)

The design of anthropomorphic prosthetic hands: A study of the Southampton Hand

The design of prosthetic hands is constrained by a series of strict conditions. Despite this, many different design strategies have been explored. One particular form is the Southampton Hand system. This is a hierarchically controlled, electrically driven hand, with multiple axes, in an anthropomorphic form. This paper details the range of mechanical solutions adopted to address the conditions. It also compares them with other solutions.

Design and development of a pneumatic anthropomorphic hand

This work deals with a pneumatically actuated hand composed of four fingers and an opposable thumb. Mechanisms to convert actuator motion into phalanx rotation were studied to make each finger as similar as possible to the human specimen. Force tactile sensors are disposed along the phalanxes to allow a closed-loop force control, while the thumb position is sensorized by a potentiometer and hence position controlled. Each component is controlled by fuzzy logic. This solution allowed the existing strong nonlinearities to be easily managed. A fuzzy supervisor applies a grasping strategy whose target is an approximate identification of the shape and size of an object to grasp it most efficiently with the disposable fingers. ©2000 John Wiley & Sons, Inc.

Design and development of a pneumatic anthropomorphic hand

Design and development of a pneumatic anthropomorphic hand

Development of an Anthropomorphic Multi-Fingered Hand and Experiments on Grasping Unknown Objects by Groping.

This paper addresses the development of at three-fingered anthropomorphic hand and discusses a strategy for grasping unknown objects by groping. In the former part of the paper, the design of the developed robot hand is presented. The robot hand has a thumb, an index finger and a middle finger with a total of nine degrees-of-freedom. The location of thumb is designed considering the opposability seen in a human hand. Eighty-seven touch sensors are distributed over the palm and fingers of this hand. In the latter part of this paper, a strategy for grasping unknown objects by groping, using the devoloped hand, is discussed. Groping is a kind of sensing. When the system does not have any models available for the objects to be grasped, active sensing becomes inevitable. The aim of the groping is to find at grasping configuration for the unknown objects. A ball, a can, a cone, at rectangular cube, and cube are chosen as the unknown objects in the experiments. Experimental results demonstrate the capability of the strategy for grasping unknown objects. This strategy needs neither models of the objects nor any complicated computations, and therefore, is useful especially for tasks in the real world.

Design of a Three-Finger Gripper for Intra-Vehicular Robotic Manipulation

In this paper a robotic gripper for manipulation of objects in micro-gravity conditions is described. The gripper has a kinematic structure with three fingers and three degrees of freedom, intermediate between a parallel jaw gripper and a complex anthropomorphic hand. It is equipped with proximity and force sensors on each finger, and aims to achieve large workspace and high grasping versatility together with the capability to perform object shape recognition and synchronous contact application.

An Intelligent Anthropomorphic Hand, with Automatic Grasp

The current designs of commercial artificial hands have a low level of innovation. As feedback to the user is difficult to achieve reliably, most devices are simple in design and operation, and limited in functional range. If information on the state of the hand, the forces and any slippage that is occurring is fed back to a microcontroller then more than one degree of freedom can be controlled and a greater and more natural functional range is possible. This paper describes the development of such a device. It outlines the design requirements, the methods of detection of the signals and the training required to operate the hand.

Servopneumatically-Driven Mechanical Hands - an Approach to Increased Grasping Flexibility

The paper surveys the development of an anthropomorphic mechanical hand which is actuated by servopneumatic drive units. The kinematic structure of the hand consists of four fingers, each with three degrees-of-freedom. The paper discusses the design and outlines the performance of the pneumatic drives and regulating units developed during the project. The controller setup for the positioning and force control is presented in combination with the aspired control hardware structure. Finally, a hierarchical structure for a flexible mission planing system is introduced.

An anthropomorphic hand exoskeleton to prevent astronaut hand fatigue during extravehicular activities.

This correspondence presents a prototype of a powered hand exoskeleton that is designed to fit over the gloved hand of an astronaut and offset the stiffness of the pressurized space suit. This will keep the productive time spent in extravehicular activity from being constrained by hand fatigue. The exoskeleton has a three-finger design, the third and fourth fingers being combined to lighten and simplify the assembly. The motions of the hand are monitored by an array of pressure sensors mounted between the exoskeleton and the hand. Controller commands are determined by a state-of-the-art programmable microcontroller using pressure sensor input. These commands are applied to a PWM driven dc motor array which provides the motive power to move the exoskeleton fingers. The resultant motion of the exoskeleton allows the astronaut to perform both precision grasping tasks with the thumb and forefinger, as well as a power grasp with the entire hand.

A dexterous anthropomorphic hand for robotic and prosthetic applications

SUMMARYThis paper outlines the analysis methodology employed in the design of an anthropomorphic hand for the purposes of object handling by robotic manipulators, and for prosthetics. The final design is described and the safe handling of various objects using this anthropomorphic hand is discussed.

PVDF ultrasonic sensors for location of small objects

Abstract Ultrasonic proximity sensors are, in general, too bulky to be placed directly on robotic end-effectors, such as grippers or anthropomorphic hands, which are also equipped with force-torque or tactile sensors and include part of the electronic unit. For this reason there is a pressing need to reduce the size and weight of any kind of sensory system mounted on robotic end-effectors and many efforts are being directed toward this aim. In the field of ultrasonic sensors, since the strong damping introduced by air imposes work at low frequency (not higher than a few hundred kHz), restricted choices of materials and transducer shape and dimension are necessary. This work presents an ultrasonic sensor for robotic grasping systems and short-range application, based on ferroelectric polymer technology, which is very light, small and cost-effective. The sensor, quite similar in configuration to what has already been considered elsewhere, consists of two unimodal transducers realized by curving a strip of 24 μm thick PVDF in a hemicylindrical configuration. The ultrasonic sensor has a theoretical resonance frequency of about 175 kHz and operates in a short range of 200 mm, although lower-frequency transducers can be used up to 400 mm. Details on the transducer design and characterization will be given and its application for the location of randomly oriented objects a few milimetres in size will be discussed. Finally, the calculation of the tilt of both flat and rough surfaces between 0 and 30° is considered.

Object-slip detection during manipulation using a derived force vector

The minimisation of grip forces during automatic manipulation, while maintaining a stable grip, requires the controlling device to be able to detect if the held object is slipping from the grasp. An algorithm, which is rapidly executable upon the controlling microprocessor, has been devised to use the changes in the contact forces between the object and the gripper to detect when this occurs. Though developed for use with an anthropomorphic hand prosthesis, the method has a wider field of application.

Dextrous Telerobotics with Force Feedback – An Overview. Part 1: Human Factors

SUMMARYComplex tasks that need to be performed through teleoperation led to the development of multifinger robot hands. A dextrous master is a multi-DOF controller which is worn by the operator in order to teleoperate these anthropomorphic hands. Force feedback is very useful when there is interaction with the environment. Providing force feedback to dextrous masters is an area of active research. We outline some of the human factors that influence the design of such masters. Of obvious importance is the hand geometry and the desired number of degrees of freedom. Additional criteria relate to the force perception of the hand. Finally, the man-machine impedance is of importance, since at the man/machine interface there are two impedances acting in series. One is the effective impedance of the human operator holding the master controller, the second is the impedance of the master controller being manipulated.

Multifingered robot hand with selfadaptability

Today, most commercially available robots are equipped with grippers which have two or three rigid fingers. Practical experience has shown that such simplified grippers represent a serious limiting factor for the application of robots to more complex tasks. In order to overcome these difficulties, a gripper of anthropomorphic structure has been developed—the robot hand. This device enables the realization of all basic grasp modes although it is controlled only by three servomotors. The hand is equipped with two mechanisms for selfadaptability which provide for a safe and reliable grasp of the target. The anthropomorphic hand structure is suitable for the implementation of expert control systems. This paper describes the mechanical construction of the hand and its functional performance.

Robotic Taction for Industrial Assembly

Assembly-line tasks were studied in order to acquire realistic estimates of requisite gripper and finger touch-sen sor design parameters. This was done in the context of noted time-and-motion variables, object configuration, weight and other physical characteristics, and any perceived requirements having to do with speed, accuracy, and delicacy. Small- and medium-sized parts assem bly was used to estimate requisite tac tile-pad-array size, resolution, and sensitivity. For each task studied, esti mates were also made for gripper con figuration and for overall difficulty of achieving the technology required. The estimated tactile-array, spatial-resolu tion needs are surprisingly small for a large variety of industrial assembly tasks. Arrays of no more than 8 X 8 pressure-sensitive points with interpoint spacing of 0.1 in and capable of sensing slippage appear to promise consider able capability. Such arrays, placed on two-jawed grippers and three-fingered anthropomorphic hands are concluded to be able to permit robotic replacement of humans in more than 80% of the assembly tasks studied.