Preliminary Study on Multibody Modeling and Simulation of an Underactuated Gripper With Differential Transmission

2021 ◽  
Author(s):  
Gabriele Maria Achilli ◽  
Silvia Logozzo ◽  
Maria Cristina Valigi ◽  
Monica Malvezzi
Keyword(s):  
Simulation Analysis ◽  
Mechanical Systems ◽  
Multibody Simulation ◽  
Elementary Model ◽  
Multibody Modeling ◽  
Multibody Model ◽  
Differential Mechanism ◽  
Grasping And Manipulation ◽  
Complex Mechanical Systems

Abstract Robotic grippers have represented a challenge for designers and engineers since at least three decades, due to the complexity of grasping and manipulation tasks. Underactuated and soft robotic grippers are a technology that allows good dexterity and manipulating capabilities, by reducing the number of actuators. However, this type of device requires the use of complex mechanical systems to compensate the underactuated implementation limits, such as differential mechanisms. The differential mechanism is necessary to decouple finger closures and distribute forces. The multibody simulation allows to evaluate the main parameters of the elements to understand how the differential system can work. The development and design of complex mechanical systems is simplified by this technique. In particular, this paper presents a multibody simulation analysis which recreates an elementary model of a gripper with two links and a single actuator; the developed model reproduces the grasping of an object using a mechanical differential pulley system, placed beneath the fingers. Some results are presented to study the role of the differential when the fingers grasp an object with different configurations. The aim of this work is to show how an accurate and still manageable multibody model integrated in Matlab environment is able to extend the classical grasp metrics to a more general dynamic setup.

scholarly journals Investigation on the Effects of Structural Dynamics on Rolling Bearing Fault Diagnosis by Means of Multibody Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Reza Golafshan ◽  
Georg Jacobs ◽  
Matthias Wegerhoff ◽  
Pascal Drichel ◽  
Joerg Berroth
Keyword(s):  
Fault Detection ◽  
Mechanical Systems ◽  
Rolling Bearing ◽  
Multibody Simulation ◽  
Bearing Fault ◽  
Transfer Path ◽  
Bearing Fault Diagnosis ◽  
Bearing Condition Monitoring ◽  
Complex Mechanical Systems

The present study aims to combine the fields modal analysis and signal processing and to show the use of Frequency Response Function (FRF), as a vibration transfer path, in enhancing reliability and abilities of the next generation vibration-based rolling bearing condition monitoring (CM) systems in complex mechanical systems. In line with this purpose, the hereby-presented paper employs an appropriate numerical model, that is, Multibody Simulation (MBS) of a vehicle’s drivetrain as a manner for numerical modal and structural analyses. For this, first, the principles of vibration-based bearing fault detection are reviewed and presented. Following that, a summary of MBS modelling and validating strategies are given. Then, the validated MBS model is used as a case study for further investigations. The results can confirm existence of challenges in fault detection of rolling bearings, in particular in complex mechanical systems. In further discussions, the capability of FRFs in fault localization and determination of ideal sensor positions is discussed in some detail. Finally, concluding remarks and suggestions for future works are summarized.

Numerical Simulation on the Effect of Compound Roof Separation Position on Bolting Performance

2014 ◽  
Vol 953-954 ◽  
pp. 1638-1642
Author(s):  
Ai Qing Liu ◽  
Jian Zhang ◽  
Peng Cheng ◽  
Yu Hai Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Surrounding Rock ◽  
Cohesive Force ◽  
Roof Strata ◽  
Poor Stability ◽  
Key Parameter

Prestress is a key parameter in bolting, while the cohesive force of layers in the compound roof strata is low and prone to separation, causing the prestress proliferation very poor. With the method of numerical simulation analysis,the location of separation in compound roof to affect the performance of bolting support was researched. It is concluded the roof separation in the edge of anchorage zone, the prestress field superpose, but is away from the deep surrounding rock and shows poor stability,however the role of cable can make up for the defect of rockbolts support. It has been found the highly prestressed strength bolting system adapts to the compound roof.

Efficient Simulation of Gear Contacts Including Transient Elastohydrodynamic Effects

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Peter Fietkau ◽  
Bernd Bertsche
Keyword(s):  
Three Dimensional ◽  
Direct Determination ◽  
Simulation Method ◽  
Elastic Half Space ◽  
Operating Conditions ◽  
Multibody Simulation ◽  
Multibody Model ◽  
Gear Contact ◽  
Oil Films ◽  
Lubrication Conditions

This paper describes an efficient transient elastohydrodynamic simulation method for gear contacts. The model uses oil films and elastic deformations directly in the multibody simulation, and is based on the Reynolds equation including squeeze and wedge terms as well as an elastic half-space. Two transient solutions to this problem, an analytical and a numerical one, were developed. The analytical solution is accomplished using assumptions for the gap shape and the pressure in the middle of the gap. The numerical problem is solved using multilevel multi-integration algorithms. With this approach, tooth impacts during gear rattling as well as highly loaded power-transmitting gear contacts can be investigated and lubrication conditions like gap heights or type of friction may be determined. The method was implemented in the multibody simulation environment SIMPACK. Therefore it is easy to transfer the developed element to other models and use it for a multitude of different engineering problems. A detailed three-dimensional elastic multibody model of an experimental transmission is used to validate the developed method. Important values of the gear contact like normal and tangential forces, proportion of dry friction, and minimum gap heights are calculated and studied for different conditions. In addition, pressure distributions on tooth flanks as well as gap forms are determined based on the numerical solution method. Finally, the simulation approach is validated with measurements and shows good consistency. The simulation model is therefore capable of predicting transient gear contact under different operating conditions such as load vibrations or gear rattling. Simulations of complete transmissions are possible and therefore a direct determination of transmission vibration behavior and structure-borne noise as well as of forces and lubrication conditions can be done.

The Role of Compliance in the Design of MEMS

1996 ◽  
Author(s):  
G. K. Ananthasuresh ◽  
Sridhar Kota
Keyword(s):  
Mechanical Design ◽  
Relevant Literature ◽  
Flexible Structures ◽  
Mechanical Systems ◽  
Great Majority ◽  
Micro Electro Mechanical Systems

Abstract A great majority of the available micro devices and systems use compliant (or flexible) structures and mechanisms. This trend in design takes advantage of micromachining techniques while satisfying the constraints imposed by them. By citing relevant literature, this article briefly notes the influence of compliance on the mechanical design and analysis of Micro-Electro-Mechanical Systems (MEMS).

Energy Method for Determining Dynamic Characteristics of Mechanisms

1949 ◽  
Vol 16 (3) ◽  
pp. 283-288
Author(s):  
B. E. Quinn
Keyword(s):  
Dynamic Characteristics ◽  
Energy Method ◽  
Mechanical Systems ◽  
Direct Approach ◽  
Graphical Methods ◽  
Applied Forces ◽  
Complex Mechanical Systems

Abstract Two types of problems are dealt with in the paper which are involved in the design of mechanisms required to have specified dynamic characteristics: (1) Determination of applied forces required to produce specified dynamic characteristics. (2) Determination of the dynamic characteristics which will result from the application of known forces. While graphical methods may be used in the solution of type (1) problems involving more or less complex mechanical systems, they do not afford a direct approach to type (2) problems. The energy method which will be outlined can be applied in either case, although this paper will be primarily concerned with the determination of the dynamic characteristics which result when a known force is applied to a given mechanism.

Managing Expectations – Contemporary Design Culture, Conservation and the Transformation of The Richards Laboratories

2018 ◽  
pp. 20-29
Author(s):  
David N. Fixler
Keyword(s):  
Mechanical Systems ◽  
University Of Pennsylvania ◽  
Architectural Form ◽  
Design Culture ◽  
Complete Work ◽  
Significant Change ◽  
Literal Expression ◽  
The University

Louis I. Kahn’s Richards Laboratories at the University of Pennsylvania are a paradoxical building. At the same time that they perhaps represent the epitome of Kahn's literal expression of structure and material hierarchy, servant and served spaces and the role of mechanical systems in determining architectural form, these powerful ideas never came together programmatically to enable a fully functional, complete work of architecture. This paper describes the quest to solve the functional conundrum and technical shortcomings of Richards, to bring the architecture and program closer together. Through a synthesis combining transformation — a significant change in use that allowed the opening of the laboratory floors to the unique light and views that were always latent in the promise of Kahn’s essential architectural idea — and rehabilitation, where the best aspects of Richards — the glazed, vitrine-like facades and the beautiful logic of the building services distribution, were renovated for enhanced performance, Kahn’s original architectural vision and present function were able to be successfully reconciled.

A Form Verification System for the Conceptual Design of Complex Mechanical Systems

1993 ◽  
Author(s):  
Jonathan S. Colton ◽  
Mark P. Ouellette
Keyword(s):  
Conceptual Design ◽  
Process Model ◽  
Mechanical Systems ◽  
Data Representation ◽  
Design System ◽  
Complex Data ◽  
Graphical Display ◽  
Design Environment ◽  
Blackboard System ◽  
Complex Mechanical Systems

Abstract This paper presents a summary of research into the development and implementation of a domain independent, computer-based model for the conceptual design of complex mechanical systems (Ouellette, 1992). The creation of such a design model includes the integration of four major concepts: (1) The use of a graphical display for visualizing the conceptual design attributes; (2) The proper representation of the complex data and diverse knowledge required to design the system; (3) The integration of quality design methods into the conceptual design; and (4) The modeling of the conceptual design process as a mapping between functions and forms. Using the design of an automobile as a case study, a design environment was created which consisted of a distributed problem solving paradigm and a parametric graphical display. The requirements of the design problem with respect to data representation and design processing were evaluated and a process model was specified. The resulting vehicle design system consists of a tight integration between a blackboard system and a parametric design system. The completed system allows a designer to view graphical representations of the candidate conceptual designs that the blackboard system generates.

Integrated Methodology for Investigation of Wagon Bogie Concepts by Simulation

2014 ◽  
Author(s):  
S. S. N. Ahmad ◽  
C. Cole ◽  
M. Spiryagin ◽  
Y. Q. Sun
Keyword(s):  
Dynamic Behaviour ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Concept Design ◽  
Multibody Simulation ◽  
Worst Case ◽  
Multibody Model ◽  
Second Stage ◽  
Force Components ◽  
Train Simulation

Implementation of a new bogie concept is an integrated part of the vehicle design which must follow a rigorous testing and validation procedure. Use of multibody simulation helps to reduce the amount of time and effort required in selecting a new concept design by analysing results of simulated dynamic behaviour of the proposed design. However, the multibody simulation software mainly looks at the dynamics of a single vehicle; hence, forces from the train configuration operational dynamics are often absent in such simulations. Effects of longitudinal-lateral and longitudinal-vertical interactions between rail vehicles have been found to affect the stability of long trains [1,2]. The effect of wedge design on the vertical dynamics of a bogie has also been discussed in [3,4]. It is important to apply the lateral and vertical forces from a train simulation into a single multibody model of a wagon to check its behaviour when operating in train configuration. In this paper, a novel methodology for the investigation of new bogie designs has been proposed based on integrating dynamic train simulation and the multibody vehicle modelling concept that will help to efficiently achieve the most suitable design of the bogie. The proposed methodology suggests that simulation of any configuration of bogie needs to be carried out in three stages. As the first stage, the bogie designs along with the wagon configurations need to be presented as a multibody model in multibody simulation software to test the suitability of the concept. The model checking needs to be carried out in accordance with the wagon model acceptance procedure established in [5]. As the second stage, the wagon designs need to be tested in train configurations using a longitudinal train dynamics simulation software such as ‘CRE-LTS’ [2], where a train set consisting of the locomotives and wagons will be simulated to give operational wagon parameters such as lateral and vertical coupler force components. As the third stage, the detailed dynamic analysis of bogies and wagons needs to be performed with a multibody software such as ‘Gensys’ where lateral and vertical coupler force components from the train simulation (second stage) will be applied on the multibody model to replicate the worst case scenario. The proposed methodology enhances the selection procedure of any alternate bogie concept by the application of simulated train and vehicle dynamics. The simulated case studies show that simulation of wagon dynamic behaviour in multibody software combined with data obtained from longitudinal train simulation is not only possible, but it can identify issues with a bogie design that can otherwise be overlooked.

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