The Design of Open-Loop Manipulator Arms With Decoupled and Configuration-Invariant Inertia Tensors

1987 ◽  
Vol 109 (3) ◽  
pp. 268-275 ◽  
Author(s):  
Kamal Youcef-Toumi ◽  
Haruhiko Asada
Keyword(s):  
Design Theory ◽  
Necessary Conditions ◽  
Diagonal Form ◽  
Kinematic Structure ◽  
Dynamic Complexity ◽  
Inertia Matrix ◽  
Mass Properties ◽  
Manipulator Arm ◽  
Manipulator Design ◽  
Reduced Dynamic

A manipulator design theory for reduced dynamic complexity is presented. The kinematic structure and mass distribution of a manipulator arm are designed so that the inertia matrix in the equation of motion becomes diagonal and/or invariant for an arbitrary arm configuration. For the decoupled and invariant inertia matrix, the system can be treated as a linear, single-input, single-output system with constant parameters. Consequently, control of the manipulator arm is simplified, and more importantly, the reduced dynamic complexity permits improved control performance. First, the problem of designing such an arm with a decoupled and/or configuration-invariant inertia matrix is defined. The inertia matrix is then analyzed in relation to the kinematic structure and mass properties of the arm links. Necessary conditions for a decoupled and/or configuration-invariant manipulator inertia matrix are then obtained. Using the necessary conditions, the kinematic structure and mass properties are found which reduce the inertia matrix to a constant diagonal form. Possible arm designs for decoupled and/or invariant inertia matrices are then determined for 2 and 3 degree-of-freedom manipulators.

Design Theory for Dynamic Complexity in Information Infrastructures: The Case of Building Internet

2010 ◽  
Vol 25 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Ole Hanseth ◽  
Kalle Lyytinen
Keyword(s):  
Complex Adaptive Systems ◽  
Adaptive Systems ◽  
Design Theory ◽  
Network Effects ◽  
Evolutionary Dynamics ◽  
Electronic Data Interchange ◽  
Dynamic Complexity ◽  
Information Infrastructures ◽  
It Capabilities ◽  
Path Dependent

We propose a design theory that tackles dynamic complexity in the design for Information Infrastructures (IIs) defined as a shared, open, heterogeneous and evolving socio-technical system of Information Technology (IT) capabilities. Examples of IIs include the Internet, or industry-wide Electronic Data Interchange (EDI) networks. IIs are recursively composed of other infrastructures, platforms, applications and IT capabilities and controlled by emergent, distributed and episodic forms of control. II's evolutionary dynamics are nonlinear, path dependent and influenced by network effects and unbounded user and designer learning. The proposed theory tackles tensions between two design problems related to the II design: (1) the bootstrap problem: IIs need to meet directly early users’ needs in order to be initiated; and (2) the adaptability problem: local designs need to recognize II's unbounded scale and functional uncertainty. We draw upon Complex Adaptive Systems theory to derive II design rules that address the bootstrap problem by generating early growth through simplicity and usefulness, and the adaptability problem by promoting modular and generative designs. We illustrate these principles by analyzing the history of Internet exegesis.

scholarly journals Finding Optimal Manipulator Arm Shapes to Avoid Collisions in a Static Environment

2020 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Tomáš Kot ◽  
Zdenko Bobovský ◽  
Mathias Brandstötter ◽  
Václav Krys ◽  
Ivan Virgala ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Particle Swarm Optimization Algorithm ◽  
Industrial Robots ◽  
Kinematic Structure ◽  
Typical Structure ◽  
Swarm Optimization ◽  
Six Degrees Of Freedom ◽  
Manipulator Arm ◽  
The Given ◽  
Collaborative Robot

In situations of a confined workplace with a lot of obstacles and a complicated required trajectory of the endpoint of an industrial or collaborative robot, it may be impossible to find a suitable robot and its position within the workplace to fulfill the given task. In some cases, it could be favorable to design a custom manipulator arm with an unusual kinematic structure or shapes of some of its links. This article presents a novel way of finding the optimal lengths and shapes of two crucial links of a manipulator arm, where the target lengths are as short as possible to reduce mass, and the shape in the form of a Bézier curve is chosen to avoid collisions. The chosen type of kinematic structure of the manipulator arm is fixed and is based on the most typical structure of existing industrial robots, with six degrees of freedom. Two algorithm variants were proposed; one method uses iterations to find the solution based on in-depth collision analysis, and the second method uses the particle swarm optimization algorithm. Both methods were implemented in a simulation system and verified in several testing workplaces.

scholarly journals Design and analysis for manipulator fixture applications

2018 ◽  
Vol 185 ◽  
pp. 00031
Author(s):  
Ming-Chu Hsieh ◽  
Zhen-Hong Khong
Keyword(s):  
Pneumatic Cylinder ◽  
Main Body ◽  
Connecting Rod ◽  
Innovative Design ◽  
Overall Design ◽  
Manipulator Arm ◽  
Gear Mechanism ◽  
Manipulator Design ◽  
Automatic Machinery ◽  
Object Of Study

The manipulators arms are the most important components in automatic machinery and equipment. These arms must conform to product requirements and match important accessory devices such as clamping jaw so that the entire process operates properly. Therefore the most important issue is that the manipulator arm has only one clamping jaw, followed by other issues such as welding and related features. In this research the manipulator arm of automated machinery with attached equipment was optimized, and the design serves as an object of study for multifunctional applications. This research emphasizes on customized manipulator design to create products with distinguished styles and characteristics, and serve as a basis for an improvement on innovative design. Manipulator arms from different manufacturers with various head-disc size and screw-hole locations were investigated, and concept of human palm was incorporated in the design to create a mechanical fixture that can be fitted into the arm. Overall design including main body of the manipulator, pneumatic cylinder set, gear and connecting rod combination, planet gear set, and linkage rods and fixture. These components were combined to offer the functions of the manipulator. Commercial software package, SolidWorks, was used to construct the model for the manipulator arm, and CAE analysis was implemented to identify the stress on the structure and possible interferences of the mobile components. Stress analysis was also performed on the gear set under pneumatic loading to ensure that the gear mechanism has a sufficient strength. The results of this study showed that an arc shaped manipulator body is the most easily handled during installation and most effectively controlled during operation. The simple profiles of the manipulator also lower the space required for storage. The design of the gear set and integrated application of the shaft helps prevent loosening of gear and shaft during operation. In this study, a manipulator was designed with three different functions, each fixture is powered by an isolated pneumatic cylinder, and this mechanism can be manipulated to form o0to o180clamping action in accordance with requirements of the task. The methods and results of this study serve as a reference for machinery industry to achieve high quality product, and also as a basis for innovative design.

scholarly journals Evaluation of long-term stability of monolithic 3D-printed robotic manipulator structures for minimally invasive surgery

2020 ◽  
Vol 15 (10) ◽  
pp. 1693-1697
Author(s):  
Yannick S. Krieger ◽  
Daniel Ostler ◽  
Korbinian Rzepka ◽  
Alexander Meining ◽  
Hubertus Feussner ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Invasive Surgery ◽  
Standard Instrument ◽  
Term Stability ◽  
Long Term Stability ◽  
Manipulator Arm ◽  
3D Printed ◽  
Manipulator Design

Abstract Purpose In the era of patient-centered medicine, clinical procedures, tools and instruments should be individually adapted to the patient. In this context, the presented 3D-printed Single-Port Overtube Manipulator System follows the aims to provide patient- and task-specific disposable manipulators for minimally invasive surgery. In a first experiment, the robustness of the monolithic flexure hinge structures in use as robotic manipulators will be investigated. Methods Customizable monolithic manipulator structures designed by means of an automated design process and manufactured with selective laser sintering were investigated with regard to long-term stability in an endurance test. Therefore, a bare manipulator arm, an arm equipped with a standard instrument and finally loaded with an additional load of 0.5 N were evaluated by continuously following a trajectory within the workspace of the manipulator arms over a period of 90 min. Results The unloaded manipulator as well as the manipulator arm equipped with a standard instrument showed a sufficient reproducibility (deviation of 1.5 mm and 2.5 mm, respectively, on average) with regard to an application as telemanipulated master–slave surgical robotic system. The 3D-printed manipulators showed no damage and maintained integrity after the experiment. Conclusion It has been shown that 3D-printed manipulators in principle are suitable for use as disposable surgical manipulator systems and offer a long-term stability over at least 90 min. The developed manipulator design shows great potential for the production of patient-, task- and user-specific robot systems. However, the manipulator geometries as well as the control strategies still show room for improvements.

Modeling, Simulation and Motion Cues Visualization of a Six-DOF Motion Platform for Micro-Manipulations

2013 ◽  
pp. 137-151
Author(s):  
Umar Asif ◽  
Javaid Iqbal
Keyword(s):  
Closed Loop ◽  
Kinematic Chain ◽  
Kinematic Structure ◽  
Motion Platform ◽  
Motion Cues ◽  
Xpc Target ◽  
Six Dof ◽  
Manipulator Design ◽  
Real Time Simulations ◽  
Actuator Design

This paper examines the problem of realizing a 6-DOF motion platform by proposing a closed loop kinematic architecture that benefits from an anthropological serial manipulator design. In contrast to standard motion platforms based on linear actuators, a mechanism with actuator design inspired from anthropological kinematic structure offers a relatively larger motion envelope and higher dexterity making it a viable motion platform for micromanipulations. The design consists of a motion plate connected through only revolute hinges for the passive joints, and three legs located at the base as the active elements. In this hybrid kinematic structure, each leg is connected to the top (motion) plate through three revolute hinges and to the bottom (fixed) plate through a single revolute joint forming a closed-loop kinematic chain. The paper describes the mathematical modeling of the proposed design and demonstrates its simulation model using SimMechanics and xPC Target for real-time simulations and visualization of the motion cues.

On the design of a direct drive 5-bar-linkage manipulator

Robotica ◽  
1991 ◽  
Vol 9 (4) ◽  
pp. 441-446 ◽  
Author(s):  
J. P. Huissoon ◽  
D. Wang
Keyword(s):  
Experimental Results ◽  
Dynamic Equations ◽  
Direct Drive ◽  
Dynamic Design ◽  
Motor Torque ◽  
Inertia Matrix ◽  
Conventional Design ◽  
Gravitational Loading ◽  
Manipulator Design ◽  
Robotic Applications

SUMMARYThe 5-bar-linkage manipulator configuration is well suited to many industrial robotic applications. Aside from kinematic suitability, the dynamic equations are greatly simplified due to a decoupling of the manipulator inertia matrix. The design also lends itself to the use of direct drive motors. However, these motors must be capable of providing a high continuous torque to counter gravitational loading in the conventional manipulator design. In this paper, the static and dynamic design of the 5-bar-linkage manipulator is analysed. A technique is proposed whereby the motor torque requirements may be reduced to a fraction of those required in the conventional design, while simultaneously retaining the advantage of a decoupled inertia matrix. Details of a prototype manipulator and experimental results of its performance are presented.

Modeling, Simulation and Motion Cues Visualization of a Six-DOF Motion Platform for Micro-Manipulations

2011 ◽  
Vol 1 (3) ◽  
pp. 1-17 ◽  
Author(s):  
Umar Asif ◽  
Javaid Iqbal
Keyword(s):  
Closed Loop ◽  
Kinematic Chain ◽  
Kinematic Structure ◽  
Motion Platform ◽  
Motion Cues ◽  
Xpc Target ◽  
Six Dof ◽  
Manipulator Design ◽  
Real Time Simulations ◽  
Actuator Design

This paper examines the problem of realizing a 6-DOF motion platform by proposing a closed loop kinematic architecture that benefits from an anthropological serial manipulator design. In contrast to standard motion platforms based on linear actuators, a mechanism with actuator design inspired from anthropological kinematic structure offers a relatively larger motion envelope and higher dexterity making it a viable motion platform for micromanipulations. The design consists of a motion plate connected through only revolute hinges for the passive joints, and three legs located at the base as the active elements. In this hybrid kinematic structure, each leg is connected to the top (motion) plate through three revolute hinges and to the bottom (fixed) plate through a single revolute joint forming a closed-loop kinematic chain. The paper describes the mathematical modeling of the proposed design and demonstrates its simulation model using SimMechanics and xPC Target for real-time simulations and visualization of the motion cues.

Deconvolution on the Euclidean motion group and planar robotic manipulator design

Robotica ◽  
2009 ◽  
Vol 27 (6) ◽  
pp. 861-872 ◽  
Author(s):  
Peter T. Kim ◽  
Yan Liu ◽  
Zhi-Ming Luo ◽  
Yunfeng Wang
Keyword(s):  
Robot Manipulator ◽  
Practical Interest ◽  
Practical Implementation ◽  
Robot Arm ◽  
Motion Group ◽  
Euclidean Motion Group ◽  
Serial Chain ◽  
Manipulator Arm ◽  
Euclidean Motion ◽  
Manipulator Design

SUMMARYSeveral problems of practical interest in robotics can be modelled as the convolution of functions on the Euclidean motion group. These include the evaluation of reachable positions and orientations at the distal end of a robot manipulator arm. A natural inverse problem arises when one wishes to design rather than to model manipulators. Namely, by considering a serial-chain robot arm as a concatenation of segments, we examine how statistics of known segments can be used to select, or design, the remainder of the structure so as to attain the desired statistical properties of the whole structure. This is then a deconvolution density estimation problem for the Euclidean motion group. We prove several results about the convergence of these deconvolution estimators to the true underlying density under certain smoothness assumptions. A practical implementation to the design of planar robot arms is demonstrated.

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