Kinematic Modeling and Analysis of a Multifingered Robotic Hand

2011 ◽  
Vol 383-390 ◽  
pp. 6684-6688
Author(s):  
P.K. Parida ◽  
Bibhuti Bhusan Biswal ◽  
M. R. Khan

Precise and secure handling of flexible or irregularly shaped objects by robotic hands has become a challenge. Robot hands used in medical robotics and rehabilitation robotics need to be anthropomorphic to do the desired tasks. Although it is possible to develop robotic hands which can be very closely mapped to human hands, it is sometimes poses several problems due to control, manufacturing and economic reasons. The present work aims at designing and developing a robotic hand with five fingers for manipulation of objects. The kinematic modeling and its analysis, as a part of the development process is presented in this paper. The simulation results of the hand shows that the conceptualized design is yielding the desired result and works very efficiently.

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
A. S. Niyetkaliyev ◽  
E. Sariyildiz ◽  
G. Alici

Abstract The robotic shoulder rehabilitation exoskeletons that do not take into consideration all shoulder degrees-of-freedom (DOFs) lead to undesirable interaction forces and cause discomfort to the patient due to the joint axes misalignments between the exoskeleton and shoulder joints. In order to contribute to the solution of this human–robot compatibility issue, we present the kinematic modeling and analysis of a novel bio-inspired 5-DOFs hybrid human–robot mechanism (HRM). The human limbs are regarded as the inner passive restrained links in the proposed hybrid constrained anthropomorphic mechanism. The proposed hybrid mechanism combines serial and parallel manipulators with rigid and cable links enabling a match between human and exoskeleton joint axes. It is designed to cover the whole range of motion of the human shoulder with the workspace free of singularities. The numerical and simulation results from the computer-aided drawing model of the mechanism are presented to demonstrate the validity of the kinematic model, and the kinematic and singularity merits of the proposed mechanism. A three-dimensional printed prototype of the hybrid mechanism was fabricated to further validate the kinematic model and its overall advantages.


2021 ◽  
Vol 6 (54) ◽  
pp. eabd2666
Author(s):  
Walter G. Bircher ◽  
Andrew S. Morgan ◽  
Aaron M. Dollar

Humans use all surfaces of the hand for contact-rich manipulation. Robot hands, in contrast, typically use only the fingertips, which can limit dexterity. In this work, we leveraged a potential energy–based whole-hand manipulation model, which does not depend on contact wrench modeling like traditional approaches, to design a robotic manipulator. Inspired by robotic caging grasps and the high levels of dexterity observed in human manipulation, a metric was developed and used in conjunction with the manipulation model to design a two-fingered dexterous hand, the Model W. This was accomplished by simulating all planar finger topologies composed of open kinematic chains of up to three serial revolute and prismatic joints, forming symmetric two-fingered hands, and evaluating their performance according to the metric. We present the best design, an unconventional robot hand capable of performing continuous object reorientation, as well as repeatedly alternating between power and pinch grasps—two contact-rich skills that have often eluded robotic hands—and we experimentally characterize the hand’s manipulation capability. This hand realizes manipulation motions reminiscent of thumb–index finger manipulative movement in humans, and its topology provides the foundation for a general-purpose dexterous robot hand.


2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Kaci E. Madden ◽  
Ashish D. Deshpande

The field of rehabilitation robotics has emerged to address the growing desire to improve therapy modalities after neurological disorders, such as a stroke. For rehabilitation robots to be successful as clinical devices, a number of mechanical design challenges must be addressed, including ergonomic interactions, weight and size minimization, and cost–time optimization. We present additive manufacturing (AM) as a compelling solution to these challenges by demonstrating how the integration of AM into the development process of a hand exoskeleton leads to critical design improvements and substantially reduces prototyping cost and time.


2015 ◽  
Vol 1115 ◽  
pp. 454-457 ◽  
Author(s):  
Alala M. Ba Hamid ◽  
Mohatashem R. Makhdoomi ◽  
Tanveer Saleh ◽  
Moinul Bhuiyan

In Malaysia, every year approximately 40000 people suffer from stroke and many of them become immobilized as an after effect. Rehabilitation robotics to assist disabled people has drawn significant attention by the researchers recently. This project also aims to contribute to this field. This paper presents a Shape Memory Alloy (SMA) actuated wearable assistive robotic hand for grasping. The proposed design is compact and sufficiently light to be used as an assistive hand. It is a joint less structure, has the potential because the human skeleton and joint replace the robot’s conventional structure. This design has been implemented on index and thumb fingers to enable grasping. Shape memory alloy springs and bias force mechanism are used for purpose of hand’s flexion and extension. This paper describes the mechatronic design of the wearable hand, experimental study of actuation unit and sensory system. Open loop experiments are conducted to understand the hand characterization and grip force provided by index finger. Current, temperature, extension and contraction of shape memory alloy springs are reported. This mechanism requires approximately 2A current for the SMA to actuate which provides maximum of 1.6N of gripping force. Conducted experiments show promising results that encourage further developments.


Author(s):  
Raymond Guo ◽  
Vienny Nguyen ◽  
Lei Niu ◽  
Lyndon Bridgwater

There has been continuous research and development to add more actuators into robotic hands to increase their dexterity. However, dexterous hands require complex control and are more costly to build. Therefore, many researchers and commercial enterprises have begun developing under-actuated robotic hands with fewer actuators and passive mechanical adaptation to not only reduce complexity and cost, but to also achieve better grasp performance in unstructured settings. This paper presents the design and analysis of the Valkyrie hand — a four fingered, tendon-driven, and under-actuated robotic hand that balances dexterity and simplicity with total 14 joints, and six degrees of actuated freedom. A derivation is provided of general dynamic and static equations for the analysis of a tendon driven mechanism, based on Euler-Lagrange formulation. The equations were used to evaluate the design parameters’ impact on the hand grasp shape and closing effort, and also validated against a design case study.


2009 ◽  
Vol 419-420 ◽  
pp. 645-648 ◽  
Author(s):  
Qun Ming Li ◽  
Dan Gao ◽  
Hua Deng

Different from dexterous robotic hands, the gripper of heavy forging manipulator is an underconstrained mechanism whose tongs are free in a small wiggling range. However, for both a dexterous robotic hand and a heavy gripper, the force closure condition: the force and the torque equilibrium, must be satisfied without exception to maintain the grasping/gripping stability. This paper presents a gripping model for the heavy forging gripper with equivalent friction points, which is similar to a grasp model of multifingered robot hands including four contact points. A gripping force optimization method is proposed for the calculation of contact forces between gripper tongs and forged object. The comparison between the calculation results and the experimental results demonstrates the effectiveness of the proposed calculation method.


2019 ◽  
pp. 1086-1108
Author(s):  
Yujian Fu ◽  
Zhijiang Dong ◽  
Xudong He

A humanoid robot is inherently complex due to the heterogeneity of accessory devices and to the interactions of various interfaces, which will be exponentially increased in multiple robotics collaboration. Therefore, the design and implementation of multiple humanoid robotics (MHRs) remains a very challenging issue. It is known that formal methods provide a rigorous analysis of the complexity in both design of control and implementation of systems. This article presents an agent-based framework of formal modeling on the design of communication and control strategies of a team of autonomous robotics, to attain the specified tasks in a coordinated manner. To ensure a successful collaboration of multiple robotics, this formal agent-based framework captures behaviors in Petri Net models and specifies collaboration operations in four defined operations. To validate the framework, a non-trivial soccer bot set was implemented and simulation results were discussed.


Robotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Santiago T. Puente ◽  
Lucía Más ◽  
Fernando Torres ◽  
and Francisco A. Candelas

This article presents a multiplatform application for the tele-operation of a robot hand using virtualization in Unity 3D. This approach grants usability to users that need to control a robotic hand, allowing supervision in a collaborative way. This paper focuses on a user application designed for the 3D virtualization of a robotic hand and the tele-operation architecture. The designed system allows for the simulation of any robotic hand. It has been tested with the virtualization of the four-fingered Allegro Hand of SimLab with 16 degrees of freedom, and the Shadow hand with 24 degrees of freedom. The system allows for the control of the position of each finger by means of joint and Cartesian co-ordinates. All user control interfaces are designed using Unity 3D, such that a multiplatform philosophy is achieved. The server side allows the user application to connect to a ROS (Robot Operating System) server through a TCP/IP socket, to control a real hand or to share a simulation of it among several users. If a real robot hand is used, real-time control and feedback of all the joints of the hand is communicated to the set of users. Finally, the system has been tested with a set of users with satisfactory results.


2020 ◽  
Vol 17 (01) ◽  
pp. 1950029
Author(s):  
Christopher Hazard ◽  
Nancy Pollard ◽  
Stelian Coros

Grasp planning and motion synthesis for dexterous manipulation tasks are traditionally done given a pre-existing kinematic model for the robotic hand. In this paper, we introduce a framework for automatically designing hand topologies best suited for manipulation tasks given high-level objectives as input. Our pipeline is capable of building custom hand designs around specific manipulation tasks based on high-level user input. Our framework comprises of a sequence of trajectory optimizations chained together to translate a sequence of objective poses into an optimized hand mechanism along with a physically feasible motion plan involving both the constructed hand and the object. We demonstrate the feasibility of this approach by synthesizing a series of hand designs optimized to perform specified in-hand manipulation tasks of varying difficulty. We extend our original pipeline 32 to accommodate the construction of hands suitable for multiple distinct manipulation tasks as well as provide an in depth discussion of the effects of each non-trivial optimization term.


Author(s):  
Xicheng Xiong ◽  
Jianhua Wei ◽  
Jian Chen

This paper deals with the development and validation of an analytical dynamic model of an air-over-hydraulic (AOH) brake system that is widely used on loaders. The AOH system is broken into five simple and cascaded subsystems, pneumatic circuit, air-hydraulic actuator, brake line, wheel cylinder, and disk brake. Pneumatic, hydraulic, and mechanical dynamics are taken care of in each subsystem. The determination of model coefficients is introduced in detail. Many experiments are performed on an experimental setup of the real AOH system on a loader and the experimental data are compared with the simulation results. Preliminary analysis shows that the simulation results are in good agreement with the experimental data. Other researchers in the areas of brake systems in construction machinery would find the model useful for similar system modeling and analysis


Sign in / Sign up

Export Citation Format

Share Document