Grasp Configurations Optimization of Dexterous Robotic Hand Based on Haptic Exploration Information

2017 ◽  
Vol 14 (04) ◽  
pp. 1750013 ◽  
Author(s):  
Haiwei Gu ◽  
Yuanfei Zhang ◽  
Shaowei Fan ◽  
Minghe Jin ◽  
Hong Liu
Keyword(s):  
Planning Process ◽  
Optimization Method ◽  
Robot Kinematics ◽  
Robotic Hand ◽  
Grasp Planning ◽  
Research Areas ◽  
Haptic Exploration ◽  
Robot Configurations ◽  
Grasp Quality

Haptic exploration and grasp planning by dexterous robot hand are usually two independent research areas. In this paper, the determination of optimal grasp configurations after haptic exploration of unknown objects is discussed. The haptic exploration information is used to select initial grasp points and the corresponding robot configurations, which greatly improve the efficiency of grasp planning process. The feasible searching regions on the object are obtained under the constrains of manipulability and robot kinematics. Then, the optimization method based on KNN search is applied to find the optimal grasp positions in feasible searching regions. The selected optimal grasp points set can achieve high grasp quality under the constrains of robot kinematics and manipulability. The optimization method combines multiple grasp quality metrics, which is fast and feasible in optimal grasp points searching. Experiments validate the feasibility and effectivity of the proposed method.

Reach to Grasp Planning for a Synergy-Controlled Robotic Hand based on Pesudo-Distance Formulation

2020 ◽  
Vol 17 (05) ◽  
pp. 2050015
Author(s):  
Zenghui Liu ◽  
Yuyang Chen ◽  
Xiangyang Zhu ◽  
Kai Xu
Keyword(s):  
Planning Process ◽  
Quality Measurement ◽  
Robotic Hand ◽  
Reach To Grasp ◽  
Grasp Planning ◽  
Object A ◽  
Position And Orientation ◽  
Low Dimensional ◽  
Power Grasp ◽  
Grasp Quality

In the past several years, grasp analysis of multi-fingered robotic hands has been actively studied through the use of posture synergies. In these grasping planning algorithms, a formulated optimization is usually performed in the hand’s low-dimensional representation together with the hand’s position and orientation. The optimization terminates at a stable grasp, often after repeated trials with different initial guesses. Furthermore, there is no guarantee that the generated grasp leads to a smooth reach-to-grasp trajectory since the grasping planning process mostly concerns hand poses with the fingers proximal to the object. A unified theoretical framework of a gradient-based iterative algorithm is hence proposed in this paper to plan a reach-to-grasp task, predicting the grasp quality and adjusting the hand’s posture synergies, position and orientation during the approaching phase to achieve a stable grasp. The grasp quality measurement is adopted from a highly efficient pseudo-distance formulation. Stable power grasp and precision pinch can be consistently and intentionally planned with different contact conditions specified in the formulation, which means that an intention for planning a power grasp would not generate a pinch result. Several numerical simulation case studies are presented to demonstrate the effectiveness of the proposed algorithm.

Precision Grasp Planning for Multi-Finger Hand to Grasp Unknown Objects

Robotica ◽  
2019 ◽  
Vol 37 (08) ◽  
pp. 1415-1437
Author(s):  
Wenyu Yan ◽  
Zhen Deng ◽  
Jinbao Chen ◽  
Hong Nie ◽  
Jianwei Zhang
Keyword(s):  
Optimization Method ◽  
Robotic Hand ◽  
Robotic Hands ◽  
Simulation Experiments ◽  
Grasp Planning ◽  
Planning Framework ◽  
Fitting Method ◽  
Dexterous Hand ◽  
Unknown Objects ◽  
Object Models

SummaryDetermining an appropriate grasp configuration for multi-finger grasping is difficult due to the complexity of robotic hands. The multi-finger grasp planning should consider not only geometry constraints of objects but also kinematics and dynamics of robotic hand. In this paper, a precision grasp-planning framework is presented for multi-finger hand to grasp unknown objects. First, the manipulation capabilities of the robotic hand are analyzed. The analysis results are further used as bases for the precision grasp planning. Second, the superquadric (SQ) fitting method is used for approximating unknown object models. Finally, a local–global optimization method is implemented to find appropriate grasp configurations for dexterous hand. The presented planning framework is validated in simulation experiments. Simulation results demonstrated that the presented grasp-planning framework enables the multi-finger hand to grasp unknown objects effectively.

A Hybrid Approach to Computer-Aided Process Planning for Prismatic Parts

1994 ◽  
Author(s):  
Y. F. Zhang ◽  
A. Y. C. Nee ◽  
J. Y. H. Fuh
Keyword(s):  
Process Planning ◽  
Hybrid Approach ◽  
Optimization Method ◽  
Optimal Operation ◽  
Operation Sequencing ◽  
Computer Aided Process Planning ◽  
Prismatic Parts ◽  
Minimum Number ◽  
Set Up

Abstract One of the most difficult tasks in automated process planning is the determination of operation sequencing. This paper describes a hybrid approach for identifying the optimal operation sequence of machining prismatic parts on a three-axis milling machining centre. In the proposed methodology, the operation sequencing is carried out in two levels of planning: set-up planning and operation planning. Various constraints on the precedence relationships between features are identified and rules and heuristics are created. Based on the precedence relationships between features, an optimization method is developed to find the optimal plan(s) with minimum number of set-ups in which the conflict between the feature precedence relationships and set-up sequence is avoided. For each set-up, an optimal feature machining sequence with minimum number of tool changes is also determined using a developed algorithm. The proposed system is still under development and the hybrid approach is partially implemented. An example is provided to demonstrate this approach.

Visual Grasp Planning for Unknown Objects Using a Multifingered Robotic Hand

2013 ◽  
Vol 18 (3) ◽  
pp. 1050-1059 ◽  
Author(s):  
Vincenzo Lippiello ◽  
Fabio Ruggiero ◽  
Bruno Siciliano ◽  
Luigi Villani
Keyword(s):  
Robotic Hand ◽  
Grasp Planning ◽  
Unknown Objects

scholarly journals DETERMINATION OF FOOT-PLATE SPACING FOR SWIVEL WALKERS BY AN OPTIMIZATION METHOD

2010 ◽  
Vol 22 (03) ◽  
pp. 213-221
Author(s):  
Chih-Hsiu Cheng ◽  
Liang-Wey Chang ◽  
Kwan-Hwa Lin
Keyword(s):  
Theoretical Work ◽  
Optimization Method ◽  
Clinical Applications ◽  
The Body ◽  
Coronal Plane ◽  
Biped Locomotion ◽  
Optimal Design Problem ◽  
Plate Spacing ◽  
Feasible Range

Swivel walkers have been useful devices in ambulation for many young paraplegic patients for being advantageous in providing reliable stability, easy handling, and hands-free walking. The placement of the foot-plates on swivel walkers affects the gait efficiency. However, the determination of the foot-plate spacing has been purely empirical and no theoretical work has been attempted before. This study aimed to develop a dynamic model of the swivel walker in the coronal plane to formulate an optimal design problem such that the energy loss due to impact could be computed and minimized within a feasible range of the coronal-plane movement. Children of heights from 0.75 to 1.45 m and weights from 15 to 45 kg fitted with the conventional swivel walkers were simulated. The results indicated that the range of the foot-plate spacing was roughly between 1/4 and 1/6 of the body heights. A regression formula was also derived to estimate foot-plate spacing with respect to the heights and weights of the simulated subjects for clinical applications. We conclude that the theoretical framework not only builds a foundation to determine the foot-plate spacing, but also reveals the dynamic behavior of the swivel walkers in the coronal plane. The results could be applied to the design of other biped locomotion systems.

Determination of Total Choline by Liquid Chromatography– Electrospray Ionization–Tandem Mass Spectrometry in Infant Formulas

2012 ◽  
Vol 95 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Shishan Fu ◽  
Baohua Tao ◽  
Shiyun Lai ◽  
Jingshun Zhang ◽  
Ren Yiping
Keyword(s):  
Electrospray Ionization ◽  
Neural Development ◽  
Internal Standard ◽  
Water Soluble ◽  
Infant Formulas ◽  
Research Areas ◽  
Hydrolyzed Protein ◽  
Evaluation Matrix ◽  
Single Laboratory

Abstract Choline is a water-soluble nutrient important for infants' brain and neural development. In infant formulas, choline is one of the important fortified nutrients. A single-laboratory validation study conducted an LC-electrospray ionization-MS/MS to determine total choline in infant formulas. Sample preparation was adopted from AOAC Official MethodSM 999.14, and instrumental running conditions were optimized. The LOQ was 0.2 μg/100 g, which is significant for measuring total choline in infant formulas. Average recoveries for milk-, rice-, soybean-, and hydrolyzed protein-based samples ranged from 86.45 ± 6.04% to 108.98 ± 3.68%, with RSD less than 7%. The repeatability RSD (RSDr) range was 0.24–3.59% in within-day evaluation and 1.16–3.24% in day-to-day evaluation. Matrix effect was also investigated, and can be effectively eliminated by using an internal standard. Therefore, this method has high credibility, and could be used as a routine method of quality control, or for clinical studies and other research areas.

Calculation of Contact Forces of Large-Scale Heavy Forging Manipulator Grippers

2009 ◽  
Vol 419-420 ◽  
pp. 645-648 ◽  
Author(s):  
Qun Ming Li ◽  
Dan Gao ◽  
Hua Deng
Keyword(s):  
Large Scale ◽  
Optimization Method ◽  
Contact Forces ◽  
Robotic Hand ◽  
Closure Condition ◽  
Contact Points ◽  
Robot Hands ◽  
Calculation Results ◽  
Forging Manipulator ◽  
Gripping Force

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.

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