Computer-aided Mechanism Research Articles

An adaptive and interpretable modeling architecture assisted rapid and reliable consensus prediction for hazardous properties of chemicals

The current research on quantitative structure-activity relationships (QSAR) of hazardous properties of compounds has significant progresses by utilizing intricate descriptors. Herein, to address the difficulties in descriptor selection and combination as well as the lack of interpretability of models, based on multi-endpoint toxicological data, an adaptive and interpretable modeling architecture is proposed to assist consensus prediction for hazardous properties of industrial chemicals. This architecture can adaptively adjust the modeling strategy according to the balanced degree of available data. After that, an integrated approach based on the concept of consensus is employed to improve the accuracy of predictions. Additionally, a novel interpretability method of feature perturbation is utilized to identify the active sites of compounds for computer-aided mechanism research. The statistical results demonstrate the outstanding performance and versatility of this structure, while the suggested interpretability strategy aids in the comprehension mechanism and enhances the dependability of the established model.

Neuropharmacological insights of African oil palm leaf through experimental assessment in rodent behavioral model and computer-aided mechanism

The present study aimed to investigate the neuropharmacological potential of methanol extract of African oil palm or Elaeis guineensis (MEEG) in Swiss albino mice and through computer-aided model. To identify the secondary metabolites in MEEG, standard phytochemical and GC-MS analyses were performed. Antidepressant activity of MEEG was assessed by forced swimming test (FST) and tail suspension test (TST) in Swiss albino mice. Besides, elevated plus maze (EPM), hole board test (HBT) and light-dark test (LDT) were used to investigate anxiolytic activities while for assessing sleeping disorder, open field test (OFT) and hole cross test (HCT) were performed. Additionally, computational and ADME/T analysis was performed using Schrödinger Maestro (v11.1) software and admetSAR online tools. The qualitative and quantitative phytochemical analyses revealed the existence of several secondary metabolites in MEEG. The oral administration of MEEG significantly reduced the immobility time in FST and TST. Similarly, promising dose-dependent anxiolytic effects were noted in all corresponding tests as compared to the control. As well, a significant decrease in the locomotion activities in experimental animals was noted during the OFT and HCT analysis. In case of computational and toxicological studies, most of the selected compounds were found considerably safe. Among the safe compounds, squalene showed promising binding energy for the antidepressant and anxiolytic activities, while stearic acid showed promising effects for the locomotion activity. The outcomes of the investigation recommend MEEG as a potential source of therapeutic candidate for the management of neurological disorders.

Insightful Valorization of the Biological Activities of Pani Heloch Leaves through Experimental and Computer-Aided Mechanisms.

Pani heloch (Antidesma montanum) is traditionally used to treat innumerable diseases and is a source of wild vegetables for the management of different pathological conditions. The present study explored the qualitative phytochemicals; quantitative phenol and flavonoid contents; in vitro antioxidant, anti-inflammatory, and thrombolytic effects; and in vivo antipyretic and analgesic properties of the methanol extract of A. montanum leaves in different experimental models. The extract exhibited secondary metabolites including alkaloids, flavonoids, flavanols, phytosterols, cholesterols, phenols, terpenoids, glycosides, fixed oils, emodines, coumarins, resins, and tannins. Besides, Pani heloch showed strong antioxidant activity (IC50 = 99.00 µg/mL), while a moderate percentage of clot lysis (31.56%) in human blood and significant anti-inflammatory activity (p < 0.001) was achieved with the standard. Moreover, the analgesic and antipyretic properties appeared to trigger a significant response (p < 0.001) relative to in the control group. Besides, an in silico study of carpusin revealed favorable protein-binding affinities. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity analysis and toxicological properties of all isolated compounds adopted Lipinski’s rule of five for drug-like potential and level of toxicity. Our research unveiled that the methanol extract of A. montanum leaves exhibited secondary metabolites that are a good source for managing inflammation, pyrexia, pain, and cellular toxicity. Computational approaches and further studies are required to identify the possible mechanism which responsible for the biological effects.

Pharmacological insights and prediction of lead bioactive isolates of Dita bark through experimental and computer-aided mechanism

Dita bark (Alstonia scholaris (L.) R. Br.) is an ethnomedicine used for the management of various ailments. This study aimed to investigate the biological properties of methanol extract of A. scholaris bark (MEAS), through in vivo, in vitro and in silico approaches alongside its phytochemical profiling. Identification and nature of the bioactive secondary metabolites were studied by the established qualitative tests and GC–MS analysis. The antidepressant activity was determined by forced swimming test (FST) and tail suspension test (TST) in mice. The anti-inflammatory and thrombolytic effect was evaluated using inhibition of protein denaturation technique and clot lysis technique, respectively. Besides, computational studies of the isolated compounds and ADME/T analysis were performed by Schrödinger-Maestro (v11.1) software, and PASS prediction was conducted through PASS online tools. The GC–MS analysis revealed the presence of several secondary metabolites in MEAS. Treatment with MEAS revealed a significant reduction of immobility time in a dose-dependent manner in FST and TST. Besides, MEAS showed substantial anti-inflammatory effects at the higher dose (400 μg/mL) as well as revealed notable clot lysis effect as compared to control. In the case of computer-aided investigation, all compounds meet the condition of Lipinski’s rule of five. PASS study also predicted for all compounds, and among these safe compound furazan-3-amine showed the most spontaneous binding energy for both antidepressant and thrombolytic activities, as well as 5-dimethylamino-6 azauracil, found promising for anti-inflammatory activity. Taken together, the investigation concludes that MEAS can be a potent source of antidepressant, anti-inflammatory, and thrombolytic agents.

Cancer diagnosis in histopathological image: CNN based approach

Abstract Breast cancer affects one out of eight females worldwide. It is diagnosed by detecting the malignancy of the cells of breast tissue. Modern medical image processing techniques work on histopathology images captured by a microscope, and then analyze them by using different algorithms and methods. Machine learning algorithms are now being used for processing medical imagery and pathological tools. Manual detection of a cancer cell is a tiresome task and involves human error, and hence computer-aided mechanisms are applied to obtain better results as compared with manual pathological detection systems. In deep learning, this is generally done by extracting features through a convolutional neural network (CNN) and then classifying using a fully connected network. Deep learning is extensively utilized in the medical imaging field, as it does not require prior expertise in a related field. In this paper, we have trained a convolutional neural network and obtained a prediction accuracy of up to 99.86%.

Integrated CAD/CAE/CAM and RP for Scorbot-ER Vu Plus Industrial Robot Manipulator

Robots are required to operate at different environmental conditions facing varieties of end-effector to workspace interactions. This paper deals with integrated CAD/CAE/CAM and RP for SCORBOT-ER Vu plus Industrial robot manipulator. It is a 5-DOF of vertical articulated robot and all the joints are revolute. Most parts of robot were three-dimensionally designed with 3D CAD, which enables effective connection with CAE analyses, the basis of which lays in kinematic simulation and structural analysis. CATIA was used to implement the cutting simulation of the robot master parts. To reduce the lead time and investment cost of developing parts, RP and CAM are selectively used to manufacture master parts for the robot body. Finally, a CAD/CAE/CAM and RP integrated system for a robot manipulator was developed. This integrated system not only promotes automation capabilities for robot manipulator production, but also simplifies the CAD/CAE/CAM and RP process for a robot manipulator. This integrated system is useful for developing automated computer-aided mechanism design and manufacturing scenario,

Teaching computer‐aided mechanism design and analysis using a high‐level mechanism toolkit

AbstractA pedagogically effective teaching strategy that integrates computer‐aided design and programming into a course on mechanism analysis and design is presented. Mechanism analysis is enhanced when coupled with computer programming that allows students to find solutions to more complex systems than would otherwise be possible. Web‐based distance learning is part of the class and students also learn how to create these kinds of materials themselves. Students can better understand the course material through an integrated computing environment. By solving mechanism design problems in C/C++, the programming skills gained in the course are widely applicable in other areas of engineering. Ch, a C/C++ interpreter, is used to incorporate programming and mechanism design because of its high‐level numerical and graphical plotting capabilities, scripting capability, and a mechanism toolkit with easy and quick animation. A student project is presented as an example to show how computer programming is integrated for effective learning. This teaching strategy has been actively used at the University of California, Davis for several years in an undergraduate course in computer‐aided mechanism design and has been adopted by other universities as well. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ 15: 277–288, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20156

A Study of the Design, Manufacture and Remote Control of a Pneumatic Excavator

In this study, a CAD/CAE/CAM and remote control integrated system for a pneumatic excavator mechanism was developed. The vector loop method and Visual C++ language were used to build the position analysis module. Pro/ENGINEER (Pro/E) was used to construct the parametric solid models. Pro/Mechanica was used to simulate the kinematic analysis. MasterCAM was used to implement the cutting simulation, and then the prototype was manufactured on a milling machine. An FB −28MC Programmable Logic Controller (PLC) and Visual Basic (VB) language were used to remote control the excavator. A demonstration example is presented to verify the design, analysis and control results. The project was useful as a supplementary teaching tool for practical computer-aided mechanism design and mechatronics courses. It was designed for educational purposes; it made use of low-cost and easy programming, and avoided the use of expensive industrial equipment.

Development of a CAD/CAE/CAM system for a robot manipulator

In this study, a CAD/CAE/CAM integrated system for a robot manipulator was developed. The D–H (Denavit–Hartenberg) coordinate transformation method was used to perform the robot position analysis, according to the transformation matrices, we used Matlab to calculate the robot position analysis. Pro/ENGINEER (Pro/E) was used to construct the robot manipulator parametric solid models, Pro/Mechanica was used to simulate the dynamic simulation and working space, MasterCAM was used to implement the cutting simulation, and the prototype was manufactured using a CNC milling machine. Finally, a CAD/CAE/CAM integrated system for a robot manipulator was developed. A demonstration example is presented to verify the design, analysis, and manufacture results (the demonstration is located at the website of http://www.sparc.nhit.edu.tw/∼jennifer/robot1/index.htm). This integrated system not only promotes automation capabilities for robot manipulator production, but also simplifies the CAD/CAE/CAM process for a robot manipulator. This integrated system is useful for developing a supplementary teaching tool for practical computer-aided mechanism design courses.

VEMECS: A virtual reality interface for spherical mechanism design

Mechanisms are one of the fundamental elements used by engineers in the design of machines. The design or synthesis of these elements has been studied for hundreds of years. More recently, the focus of kinematic synthesis research has been in reformatting the graphical synthesis methods into an analytical form compatible with computer processing. One of the thrusts of this research concentrates on the human/computer interface (HCI) between the user and the computer design software. The work presented in this paper addresses this issue of developing a new HCI for mechanism design based on virtual reality techniques. Current computer-aided mechanism design can be seen in the areas of analysis, topological, and dimensional synthesis (Erdman 1995). In each of these areas, the trend is toward developing user interfaces that are more compatible with the cognitive and perceptual nature of the designer. Mechanism synthesis computer programs like KINSYN (Rubel et al . 1977), LINCAGES-4 (Erdman and Riley 1981) and SPHINX (Larochelle et al . 1993) utilize the traditional HCI of monitor, keyboard and mouse. More recently, virtual reality (VR) is being examined as a natural human interface for mechanism design. Osborn (1994) developed the first virtual environment for the synthesis of spherical four-bar mechanisms, SphereVR, which used the Newton-Raphson iterative approach to solve the design equations. This paper takes a slightly different approach by combining the reliable and robust solution algorithms of SPHINX1.0 with VR technology. VR is used for all interaction, manipulation, and navigation throughout the design process, while SPHINX1.0 computational routines are used for computing the solution mechanisms. Natural and intuitive skills of the designer are used through reliance on a head tracked three-dimensional display and three-dimensional interaction. The result is a program called VEMECS (Virtual Environment MEChanism Synthesis). This paper outlines the organization and operation of VEMECS, and concludes with a discussion of the lessons learned in development and implementation of this approach.

Object-oriented cam design through the internet

We have developed a Web-based interactive cam design package under the programming paradigm of the \( {\text{C}}^{\text{H}} \) language environment. This package was initially developed as a teaching and learning tool for educational use in an undergraduate Computer-Aided Mechanism Design course. Because the system is Web-based and implemented through a client/server model with the user interface through the Web browser, it is easy to use and maintain. The system can also be used to solve practical engineering cam design problems with flat or roller followers and with translating or oscillating motion types. The system can be used to generate the cam profile, transmission angle, position, velocity, and acceleration of the follower. Once a cam/follower system is designed, animation of the cam/follower system can be performed. At the end of the design, the CNC code for manufacturing the designed cam can also be produced through our Web-based cam design system. The package consists of a number of modules including various Web pages, common gateway interface (CGI) programs, a \( {\text{C}}^{\text{H}} \) program called cam.ch, and the CCam \( {\text{C}}^{\text{H}} \) class which performs the necessary computation for cam design. Two different versions of the cam design package have been designed and implemented. One runs the cam design program on the client machine as a \( {\text{C}}^{\text{H}} \) applet, and the other runs the cam design program on the Web server through CGI. In this paper, details of design and implementation of Web-based cam design package will be described. Two application examples with different motion types for the follower will be used to illustrate features of the applet-based and CGI-based implementation schemes. The ideas of the Web-based software design presented in this paper can be applied to other application areas.

Computer-Aided Mechanism Elucidation of Acetylene Hydrocarboxylation to Acrylic Acid Based on a Novel Union of Empirical and Formal Methods

In the elucidation of complex multistep reactions, it is easy to overlook significant mechanistic hypotheses. Hence, the use of computer programs to search for mechanisms is attractive, but these programs must respect the prior knowledge held by the investigator. Virtually all knowledge-based programs accommodate prior knowledge of either what can or what cannot happen, but there are advantages in exploiting both types of knowledge simultaneously. We report a novel alliance of two programs that enables these advantages and which represents an advance in the capabilities of computational chemistry, as illustrated here on the complex synthesis of acrylic acid from acetylene, CO, and water catalyzed by palladium complexes. The pathways reported by the programs were categorized as hydride, hydroxycarbonyl (alcoholate-like), and metallocyclic, the mechanistic types that are known from publications on hydrocarboxylation and hydrocarbalkoxylation of unsaturated molecules in solutions of transition metal complexe...

Computer-Aided Mechanism Design: Now and the Future

The current status of computer-aided design of mechanisms is reviewed. The available software is described and several industrial examples are presented to illustrate current trends in the field of linkage design and analysis. Future strategies and CAD environments are also discussed.

Computer-Aided Mechanism Design: Now and the Future

The current status of computer-aided design of mechanisms is reviewed. The available software is described and several industrial examples are presented to illustrate current trends in the field of linkage design and analysis. Future strategies and CAD environments are also discussed.

Computer-aided mechanism synthesis based on the Burmester theory

Computer-aided synthesis of mechanisms becomes very effective when personal computers with graphic display are used. The hardware provides the possibility to realize an interactive process between man and machine, the so called man-machine-dialogue. In this paper, based on the Burmester theory, algorithms for numerical synthesis of four bar linkage mechanisms and their PC implementation are presented. Depending on the design restrictions present, several solutions are obtained. In order to evaluate these solutions, it is necessary to analyze the mechanisms directly after synthesis. An overview of the operation and working-space of the mechanism for the entire range of motion is presented using animation techniques. This process is called “Synthesis by Iterative Analysis”.

Pedagogically effective programming environment for teaching mechanism design

The CH programming environment is an open system. Users can enhance the system through its various user interfaces. CH is specially designed for applications in mechanical systems engineering, although it is applicable to many other disciplines as well. CH has been successfully used as a teaching and learning tool for an undergraduate course, Computer-Aided Mechanism Design, at the University of California, Davis in Fall 1993. In this article we will present the CH programming environment and programming features developed for teaching and student learning. We will describe how a teaching toolbox is developed and used for teaching mechanism design. Source codes in the teaching toolbox are available to students so that they can study the software implementation of algorithms and modify the codes to solve similar problems. Although the developed teaching toolbox is specific for instruction on mechanism design, the CH programming environment and ideas presented in this article are general, and they are applicable to instructional improvement for a wide range of subjects in engineering.

Finitely and Multiply Separated Synthesis of Link and Geared Mechanisms Using Symbolic Computing

A computer amenable symbolic computing approach for the synthesis of six different link and geared mechanisms is presented. Burmester theory, complex number algebra, and loop closure equations are employed to develop governing equations for the mechanism to be synthesized. Closed-form and iterative solution techniques have been developed which permit synthesis of six-link Watt and Stephenson chains for function, path, and motion generation tasks with up to eleven precision points. Closed-form solution techniques have also been developed for the synthesis of geared five-bar, six-bar, and five-link cycloidal crack mechanisms, for synthesis tasks with up to six finitely and multiply separated precision points. The symbolic manipulation language MACSYMA is used to simplify the resulting synthesis equations and obtain closed-form solutions. A design methodology which demonstrates the feasibility and versatility of symbolic computing in computer-aided mechanisms design is outlined. A computer program which incorporates these synthesis procedures is developed. Two examples are presented to illustrate the role of symbolic computing in an automated mechanism design process.

Computer-aided mechanism design: a symbolic-computing approach

A computer-amenable symbolic-numerical computing blend for solving precision position-type function-, path- and motion-generation problems for six link and geared mechanisms is presented. Burmester theory, complex-number algebra and loop-closure equations are used to develop the synthesis equations for the mechanism to be designed. Closed-form and iterative solution techniques are presented which permit a synthesis of the 6-link Watt and Stephenson-II and Stephenson-III mechanisms for function-, path- and motion-generation tasks with up to 11 precision points. Closed-form solution techniques are also presented for synthetizing geared 5-bar, 6-bar and 5-link cycloidal crank mechanisms for up to six finitely and multiply separated precision points. The symbolic-manipulation language macsyma is used to carry out algebraic manipulations to help simplify the synthesis equations. A 2-step computer-aided mechanism-design procedure which combines symbolic and numerical computing is presented. The feasibility and versatility of this approach in an automated mechanism-design process is demonstrated using three example problems.

Computer-aided modelling and simulation of mechanisms and manipulators

Some choices related to the design and implementation of computer programs for the kinematic modelling and simulation of mechanisms and manipulators are discussed, including global versus modular modelling features, numeric versus symbolic computation, and precompiler versus interpreter implementation. Within this framework, two original applications are presented: first, a program for modelling spatial single-loop robot arms that works as a precompiler of manipulators and reaches an automatic, symbolic, closed-form solution to the inverse position analysis; and second, an approach to friendly training in computer-aided mechanism design through hypertext. Various examples of implementations are given.

Considering cost effective computer-aided mechanism design

The following discussion considers computer-aided mechanism design in terms of the practical designer's concern — cost effectiveness. Applied design philosophy is reviewed to examine various types of software, both traditional and innovative. The situation of small/medium companies considering acquisition of such software is primarily addressed. The development of the ‘Subroutine Package’ approach is described and its merits compared to conventional general purpose software packages. A subroutine package approach to mechanism design, considers a system to be composed of a limited number of constituent elements. Each subroutine in a package models the behaviour of such an element. An example, which has been developed, is the Linkage Analysis Package (LAP), and an example of its use is given. The user writes a simple (Fortran) calling program to input/output data and call the appropriate subroutines. This represents a ‘self-customized’ interface that is inherently highly cost effective. As the design problem changes, the same interface may be used after limited modification and reselection of the necessary subroutines. Thus a flexible, user-friendly and low-cost computer-aided design tool is available to designers, solving all but the most specialized problems.