Dynamics, Contact Motion and Control of Dual Arm Object Manipulation With Soft Rolling Fingertips

2002 ◽  
Author(s):  
Zoe Doulgeri ◽  
John Fasoulas
Keyword(s):  
Horizontal Plane ◽  
Contact Forces ◽  
Kinematics And Dynamics ◽  
Object Surface ◽  
Contact Mode ◽  
Motion Models ◽  
And Control ◽  
Detailed Derivation ◽  
Simple Feedback ◽  
Dual Arm

In this paper a detailed derivation is made of the kinematics and dynamics of a pair of robotic fingers manipulating a rectangular object with soft fingertips that are allowed to roll along the object surface. The whole system is confined to the horizontal plane. Two contact motion models for the soft area contact are considered and it is shown that they significantly affect contact mode and type of finger rolling constraints. A discussion on contact forces and a grasp analysis at object’s equilibrium is made. Last, simple feedback control solutions that have been proposed for stabilizing the grasping and regulating the object’s posture are presented.

Human Motion Modeling With a Robotics Method: Analysis of a Person Riding a Bus

2008 ◽  
Author(s):  
Ashish D. Deshpande ◽  
Jonathan E. Luntz
Keyword(s):  
Equations Of Motion ◽  
Human Motion ◽  
Contact Forces ◽  
Body Motion ◽  
Control Analysis ◽  
Motion Modeling ◽  
Open Chain ◽  
Motion Models ◽  
Performance Requirements ◽  
And Control

Deriving models of human body motion is important for prosthetics, rehabilitation and development of humanoids. We present a method that simplifies the derivation of equations of motion of human movements. We illustrate our approach by deriving motion models of a person riding in a moving bus. Our approach simplifies the derivation of dynamics as only open chain dynamics are to be derived. The kinematic constraints are then introduced to represent a complete system model in which the contact forces appear explicitly. We then constrain the contact forces based on the performance requirements to determine the feasibility of motions, which is difficult to determine with the traditional methods. Our model allows for the design and control analysis, specifically, the derivation of the relationship between the change in rider’s posture and the feasibility of motions.

Experimental Investigation on the Rubbing Process of Labyrinth Seals Considering the Material Combination

2020 ◽  
Author(s):  
Lisa Hühn ◽  
Oliver Munz ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer
Keyword(s):  
Turbine Blades ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Contact Forces ◽  
Experimental Investigations ◽  
Process Data ◽  
Labyrinth Seals ◽  
Material Combination ◽  
Higher Temperature ◽  
And Control

Abstract Labyrinth seals are used to prevent and control the mass flow rate between rotating components. Due to thermally and mechanically induced expansions during operation and transient flight maneuvers, a contact, the so-called rubbing process, between rotor and stator cannot be excluded. A large amount of rubbing process data concerning numerical and experimental investigations is available in public literature as well as at the Institute of Thermal Turbomachinery (ITS). The investigations were carried out for different operating conditions, material combinations, and component geometries. In combination with the experiments presented in this paper, the effects of the different variables on load due to rubbing are compared, and discussed with the focus lying on the material combination. The influence of the material on the loads can be identified as detailed as never before. For example, the contact forces in the current experiments are higher due to a higher temperature resistance of Young’s modulus. The analysis will also be based on the rubbing of turbine blades. Design guidelines are derived for labyrinth seals with improved properties regarding tolerance of rub events. Based on the knowledge obtained, guidelines for designing reliable labyrinth seals for future engines are discussed.

scholarly journals Comparative study on the redundancy of mobile single- and dual-arm robots

2016 ◽  
Vol 13 (6) ◽  
pp. 172988141666678
Author(s):  
Hongxing Wang ◽  
Ruifeng Li ◽  
Yunfeng Gao ◽  
Chuqing Cao ◽  
Lianzheng Ge
Keyword(s):  
Rate Control ◽  
Control Algorithm ◽  
Redundant Robot ◽  
Motion Models ◽  
Redundant Robots ◽  
Operational Space ◽  
Rate Control Algorithm ◽  
Simulation Results ◽  
Dual Arm Robot ◽  
Dual Arm

A whole resolved motion rate control algorithm designed for mobile dual-arm redundant robots is presented in this article. Based on this algorithm, the end-effector movements of the dual arms of the mobile dual-arm redundant robot can be decomposed into the movements of the two driving wheels of the differential driving platform and the movements of the dual-arm each joint of this robot harmoniously. The influence of the redundancies of the single- and dual-arm robots on the operation based on the fixed- and differential-driving platforms, which are then based on the whole resolved motion rate control algorithm, is studied after building their motion models. Some comparisons are made to show the advantages of this algorithm on the entire modeling of the complicated robotic system and the influences of the redundancy. First, the comparison of the simulation results between the fixed single-arm robot and the mobile single-arm robot is presented. Second, a comparison of the simulation results between the mobile single-arm robot and the mobile dual-arm robots is shown. Compared with the mobile single-arm robot and the fixed dual-arm robot based on this algorithm, the mobile dual-arm robot has more redundancy and can simultaneously track and operate different objects. Moreover, the mobile dual-arm redundant robot has better smoothness, more flexibility, larger operational space, and more harmonious cooperation between the two arms and the differential driving platform during the entire mobile operational process.

On the Use of Actively Controlled Auxiliary Bearings in Magnetic Bearing Systems

2008 ◽  
Author(s):  
Iain S. Cade ◽  
M. Necip Sahinkaya ◽  
Clifford R. Burrows ◽  
Patrick S. Keogh
Keyword(s):  
Controller Design ◽  
Control Strategies ◽  
Frictional Heating ◽  
Magnetic Bearing ◽  
Contact Forces ◽  
Active Magnetic Bearing ◽  
Physical Limit ◽  
Drop Tests ◽  
Auxiliary Bearing ◽  
And Control

Auxiliary bearings are used to prevent rotor/stator contact in active magnetic bearing systems. They are sacrificial components providing a physical limit on the rotor displacement. During rotor/auxiliary bearing contact significant forces normal to the contact zone may occur. Furthermore, rotor slip and rub can lead to localized frictional heating. Linear control strategies may also become ineffective or induce instability due to changes in rotordynamic characteristics during contact periods. This work considers the concept of using actively controlled auxiliary bearings in magnetic bearing systems. Auxiliary bearing controller design is focused on attenuating bearing vibration resulting from contact and reducing the contact forces. Controller optimization is based on the H∞ norm with appropriate weighting functions applied to the error and control signals. The controller is assessed using a simulated rotor/magnetic bearing system. Comparison of the performance of an actively controlled auxiliary bearing is made with that of a resiliently mounted auxiliary bearing. Rotor drop tests, repeated contact tests, and sudden rotor unbalance resulting in trapped contact modes, are considered.

scholarly journals Typical configuration analysis of a modular reconfigurable cable-driven parallel robot

2019 ◽  
Vol 16 (2) ◽  
pp. 172988141983475 ◽  
Author(s):  
Tao Zhao ◽  
Bin Zi ◽  
Sen Qian ◽  
Zeqiang Yin ◽  
Dan Zhang
Keyword(s):  
Inverse Kinematics ◽  
Parallel Robot ◽  
Structure Design ◽  
Kinematics And Dynamics ◽  
Lagrange Method ◽  
Practical Applications ◽  
Task Requirements ◽  
Dynamics Models ◽  
Typical Configuration ◽  
And Control

To obtain better flexibility and multifunction in varying practical applications, several typical configurations of a modular reconfigurable cable-driven parallel robot are analyzed in this article. The spatial topology of the modular reconfigurable cable-driven parallel robot can be reconfigured by manually detaching or attaching the different number of modular branches as well as changing the connection points on the end-effector to satisfy diverse task requirements. The structure design of the modular reconfigurable cable-driven parallel robot is depicted in detail, including the design methodology, mechanical description, and control architecture. The inverse kinematics and dynamics of the modular reconfigurable cable-driven parallel robot considering diverse configurations are derived according to the vector closed rule and Lagrange method, respectively. The numerical simulation and related experiments of a typical configuration are achieved and analyzed. The results verify the effectiveness and feasibility of the inverse kinematics and dynamics models for the modular reconfigurable cable-driven parallel robot.

Design of Measure and Control System of the Ring Block Casing Wear Tester

2013 ◽  
Vol 423-426 ◽  
pp. 2414-2418
Author(s):  
Xiang Tong Yang ◽  
Xiao Zeng Wang ◽  
Yin Ping Cao ◽  
Yi Hua Dou
Keyword(s):  
Control System ◽  
Calibration Method ◽  
Contact Forces ◽  
Wear Depth ◽  
Friction Forces ◽  
Deep Wells ◽  
Geological Conditions ◽  
Casing Wear ◽  
Measure And Control System ◽  
And Control

In deep wells and ultra-deep wells the complex geological conditions often result in serious casing wear. In order to obtain the wear efficiency which is used to compute the wear depth of downhole casing, the ring block drillpipe casing wear tester is developed. The measure and control system which include the measure circuits of contact forces between casing and drillpipe samples, the measure circuits of the friction forces are main component of wear tester. It is very important to design the measure and control system of tester. The paper also develops the calibration method of the loads sensors used to measure the contact and friction force. The wear tester can accurately measure the wear efficiency and the friction coefficient needed by casing wear prediction.

Monitoring and Control of Dual-Arm Industrial Robot Tasks Using IoT Application and Services

2015 ◽  
Vol 762 ◽  
pp. 255-260 ◽  
Author(s):  
Mircea Murar ◽  
Stelian Brad
Keyword(s):  
Experimental Testing ◽  
Industrial Robot ◽  
Cyber Physical Systems ◽  
Monitoring And Control ◽  
Research Directions ◽  
Physical Systems ◽  
Selection For ◽  
Robot Tasks ◽  
And Control ◽  
Dual Arm

In the context of latest technological revolution, Industry 4.0, connectivity and therefore access and control of cyber-physical systems and resources from any place, at any time by any means represent a technological enabler of crucial importance. The first part of this paperwork contains a brief introduction of cyber-physical systems and IoT concepts, together with a review of major IoT providers. The second part introduces an approach towards achieving connectivity and remote control of task selection for a dual-arm industrial robot using a commercially available IoT infrastructure and technology provided by ioBridge. Within the third part, details about experimental testing and evaluation of the selected solutions are presented. The last part is allocated for conclusions and further research directions.

Micro/Macro or Link-Integrated Micro-actuator Manipulation—A Kinematics and Dynamics Perspective

2006 ◽  
Vol 129 (10) ◽  
pp. 1086-1093 ◽  
Author(s):  
J. Zhang ◽  
J. Rastegar
Keyword(s):  
Dynamic Response ◽  
Closed Loop ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
High Harmonic ◽  
Kinematics And Dynamics ◽  
Control Problems ◽  
End Effector ◽  
Micro Actuators ◽  
And Control

Smart (active) materials based actuators, hereinafter called micro-actuators, have been shown to be well suited for the elimination of high harmonics in joint and/or end-effector motions of robot manipulators and in the reduction of actuator dynamic response requirements. Low harmonic joint and end-effector motions, as well as low actuator dynamic response requirements, are essential for a robot manipulator to achieve high operating speed and precision with minimal vibration and control problems. Micro-actuators may be positioned at the end-effector to obtain a micro- and macro-robot manipulation configuration. Alternatively, micro-actuators may be integrated into the structure of the links to vary their kinematics parameters, such as their lengths during the motion. In this paper, the kinematics and dynamics consequences of each of the aforementioned alternative are studied for manipulators with serial and closed-loop chains. It is shown that for robot manipulators constructed with closed-loop chains, the high harmonic components of all joint motions can be eliminated only when micro-actuators are integrated into the structure of the closed-loop chain links. The latter configuration is also shown to have dynamics advantage over micro- and macro-manipulator configuration by reducing the potential vibration and control problems at high operating speeds. The conclusions reached in this study also apply to closed-loop chains of parallel and cooperating robot manipulators.

Design and Analysis of a Multimodal Grasper Having Shape Conformity and Within-Hand Manipulation With Adjustable Contact Forces

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Nagamanikandan Govindan ◽  
Asokan Thondiyath
Keyword(s):  
Control Strategies ◽  
Low Cost ◽  
Active Surface ◽  
Force Sensor ◽  
Contact Forces ◽  
Geometrical Shape ◽  
Planning And Control ◽  
Control Scheme ◽  
And Control ◽  
Compact Mechanism

Abstract This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface. The proposed grasper has two important qualities: versatility and less complexity. The former refers to the ability to grasp a range of objects having different geometrical shape, size, and payload and perform in-hand manipulations such as rolling and sliding, and the latter refers to the uncomplicated design, and ease of planning and control strategies. Increasing the number of functions performed by the grasper to adapt to a variety of tasks in structured and unstructured environments without increasing the mechanical complexity is the main interest of this research. The proposed grasper consists of two hybrid jaws having a rigid inner structure encompassed by a flexible, active gripping surface. The flexibility of the active surface has been exploited to achieve shape conformation, and the same has been utilized with a compact mechanism, introduced in the jaws, to vary the contact forces while grasping and manipulating an object. Simple and scalable structure, compactness, low cost, and simple control scheme are the main features of the proposed design. Detailed kinematic and static analysis are presented to show the capability of the grasper to adjust and estimate the contact forces without using a force sensor. Experiments are conducted on the fabricated prototype to validate the different modes of operation and to evaluate the advantages of the proposed concept.

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