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In this article, a novel fault detection method based on adaptive wavelet packet feature extraction and relevance vector machine (RVM) is proposed for incipient fault detection of gear. First, ten statistical characteristics in time domain and all node energies of full wavelet packet tree are extracted as candidate features. Then, Fisher criterion is applied to evaluate the discrimination power of each feature. Finally, two optimal features from time domain and wavelet domain, respectively, are selected to be used as inputs to the RVM. Furthermore, moving average is applied to each feature to improve accuracy for online continuous fault detection. By combining wavelet packet transform with Fisher criterion, it is able to adaptively find the optimal decomposition level and select the global optimal features. The RVM, a Bayesian learning framework of statistical pattern recognition, is adopted to train the fault detection model. The RVM was compared with the popular support vector machine (SVM) with the increase of training samples. Experimental results validate the effectiveness of the proposed method, and indicate that RVM is more suitable than SVM for online fault detection.

Taking into account the scarcity of feasible fertilizing rate feedback from on-board sensors and the limited computation power of controller mounted on the variable-rate granular fertilizer applicator, optimum control index chart is a good option for controller design to achieve accurate variable-rate fertilizing control. The index chart contains a list of optimum control parameters optimized to meet combined objectives: fertilizing accuracy, energy saving and fertilizing consistency. To generate such list, the probabilistic meta-model based on Gaussian Processes (GP) is firstly utilized to identify the variable-rate fertilizing process with the indoor experimental data. Consequently, the meta-model-based optimization process is presented with the given fertilizing rate, previous opening length and its adjusting direction. The optimal control parameters chart is obtained by the iterative multi-objectives optimization based on Genetic Algorithm (GA). Thus, the fertilizing prescription can be converted to the controller's actions by searching the optimum control parameters chart. The well-trained GP models predict the fertilizing rate and the fertilizing coefficient of variation with limiting mean relative error to 0.014 and 0.089, respectively. Finally, by considering four main error sources, the verified fertilizing model improves the average fertilizing rate error to no more than 5% at given management zone scale in field test.

The efficiency of data processing is critical for the on-line monitoring applications of industrial components and systems, both from the viewpoints of the rapid adaptation to the non-stationary signals and the cost of information storage and transmission. In this paper, we propose an enhanced feature extraction model for machinery performance assessment, which is based on the lifting-based wavelet packet transform (WPT) and sampling-importance-resampling methods. The lifting-based WPT decomposes the signals. Then the sampling-importance-resampling procedure is applied in the wavelet domain to extract the distribution information and compose the feature vectors. Finally, a support vector machine is used to assess the normal or abnormal condition based on these extracted features. To validate the proposed new model, an endurance test of pressure regulators has been carried out. Compared to the traditional wavelet packet method, the new model can not only keep the precision level but also improve the efficiency by over 60%.

This paper proposes a hybrid decision support model within a multi-agent framework to facilitate integration and collaboration for design decisions. The hybrid decision model integrates the compromise decision support problem technique (cDSP) and the fuzzy synthetic decision model (FSD) to quantitatively incorporate qualitative design knowledge and preferences of designers for multiple, conflicting attributes stored in a knowledge repository so that a better understanding of the consequences of design decisions can be achieved from a more comprehensive perspective. The focus of this work is on the provision of a hybrid decision model and framework for improved cooperative design decision support. The novelty of the work is in combination of different models or methods, algorithms for making collaborative design decisions in both objective and subjective natures, in particular the fuzzy negotiation mechanism using the hybrid decision model. The developed hybrid decision model and framework are generic and flexible enough to be used in a variety of decision problems. Finally, the proposed hybrid decision model and framework are illustrated with applications in collaborative concept evaluation and selection in product family design for mass customization.

A novel intelligent drug delivery system potential for the more effective therapy of the diabetics was proposed, and the composition of system was analyzed. Based on the design of micro-electro-mechanical systems (MEMS), an iterative modeling process was introduced. Unified modeling language (UML) was employed to describe the function requirement, and different diagrams were built up to explore the static model, the dynamic model and the employment model. The mapping analysis of different diagrams can simply verify the consistency and completeness of the system model.

Given complexity of the design and manufacturing processes of microelectromechanical system (MEMS) products, we present a unified modeling language (UML) based design approach for multi-domain products or systems like MEMS to designing and evaluating possible solutions at the early design stage to shorten their development time. Specifically, the proposed approach is used to model and analyze a novel drug delivery system combining MEMS devices and integrated circuit (IC) units. This drug delivery system aims to be used for safer and more effective therapy of the diabetics. Two design models about the whole drug delivery system and its micropump subsystem are established using UML diagrams; in particular a composition diagram with components and ports describes the topology of the system. Through design and simulation on the micropump subsystem, it is found that the variations of geometrical dimension and excitation voltage affect the characterization of the micropump. The simulation results demonstrate and validate the proposed approach, and can be used as a significant reference for the designer to design the optimal micropump.

A novel control scheme for hydraulic servo systems with large frictional torques is proposed based on a sliding-mode variable structure controller combined with a frictional state observer. The sliding-model variable structure control law and the sliding-model frictional state observer are detailed. The LuGre dynamic friction model is adopted to estimate the frictional torques and reduce the effects caused by the nonlinear frictions. Experimental research on hollow hydraulic motor systems is carried out to validate the proposed control scheme. The experimental results show that the application of the proposed control scheme is successful and the good position-tracking performance with high precision is attained in the presence of dynamic frictions even with large frictional torques and very low velocities.

This article investigates mechanical behavior of a circular piezoelectric actuator for valveless micropumps. An analytical equation for analyzing the deflection of multi-layer piezoelectric structure is derived based on the electro-elastic theory and the thin plate theory. We assume that the distribution of electric potential along the thickness direction is governed by the square law to satisfy the Maxwell static electricity equation. The validity of the proposed analytical model is further studied by using the ANSYS software. Furthermore, the effects of the dimensions and material properties of a multi-layer piezoelectric structure on its deflection are analyzed for optimal design of the actuator. The simulation results show that the thickness ratio of the piezoelectric layer and the passive plate in the multi-layer structure can be optimized to obtain the largest deflection. The important design parameters of the piezoelectric actuator, such as the passive plate properties and material, and the piezoelectric layer dimension and material, and the bonding layer dimension and its excitation voltage, should be selected to improve the performance of the valveless micropump.

We designed a valveless micropump excited by a piezoelectric actuator for medical applications. The complete electric–fluid–solid coupling model is built upon using ANSYS software (Canonsburg, PA) to investigate the behaviors of the micropump. The effects of the geometrical dimensions on the micropump characteristics and its efficiency are analyzed. The simulation results show that there is an optimal thickness of the piezoelectric layer to obtain a large pump flow, and that this optimal thickness is affected by the material and the thickness of the pump membrane. To enhance the performance of the micropump, some important diffuser parameters, such as the diffuser length, the diffuser angle, and the neck width, should be optimized. However, the variations of the diffuser’s geometrical dimensions do not affect the optimal thickness of the piezoelectric layer.

Assemblability analysis and evaluation plays a key role in assembly design, operation analysis and planning. In this paper, we propose an integrated intelligent approach and framework for evaluation of assemblability and assembly sequence for electro-mechanical assemblies (EMAs). The approach integrates the STEP (STandard for the Exchange of Product model data, officially ISO 10303)-based assembly model and XML schema with the fuzzy analytic hierarchy process for assembly evaluation. The evaluation structure covers not only the geometric and physical characteristics of the assembly parts but also the assembly operation data necessary to assemble the parts. The realization of the integration system is implemented through a multi-agent framework. Through integration with the STEP-based product modeling agent system, CAD agent system and assembly planning agent system, the developed assembly evaluation agent system can effectively incorporate, exchange, and share concurrent engineering knowledge into the preliminary design process so as to provide users with suggestions for improving a design and also helping obtain better design ideas. The applications show that the proposed approach and system are feasible.

This paper presents the development of a web-enabled database system for MEMS design and manufacturing which can provide the networked design and manufacturing services over the Internet. Specifically, the data obtained from various sources for MEMS manufacturing processes/materials are organised as databases by using the relational database management systems (RDBMS), Microsoft Access and MySQL. The database system can be accessed from a Java application as well as an applet. The stand-alone Java application is created using JFC Swing, JDBC and SQL, and the Java applet is subsequently created to enable web functionality. The underlying database is open, extensible through a set of administrator tools or via the web, which gives commercial design and manufacturing facilities the ability to update their own materials, processes and rules. This plays a crucial role in the system for advisory MEMS manufacturing service and concurrent collaborative MEMS design and simulation. The developed database system, e-MEMS Designer @Database, which contains extensive manufacturing or fabrication processes and materials databases for MEMS and microelectronics, is easily incorporated as a sub-system into both the standalone system and the web-enabled MEMS design system, MEMS Designer, which is being developed. The database system can also be updated to create a comprehensive data warehouse and an advisory system for MEMS manufacturing processes/materials selection.

Contemporary design problems embody significant levels of complexity, which make it unlikely that a single designer can work alone on a complex design problem. Knowledge-intensive collaboration has emerged as a promising discipline for dealing with the modeling and decision-making processes in distributed design systems. In this paper, we present the implementation and application of a web-based knowledge-intensive collaborative design support system called WebKIDSS. With the modularization of design, a modules networked system could be developed and deployed according to CORBA standard to facilitate the rapid construction of the concurrent integrated distributed models for the design process and the coordination among designers within the range of enterprises and even virtual enterprises. The prototype web-based collaborative design platform, is implemented for proof-of-concept through the distributed knowledge server based framework (KS-DMME) with concurrent integration of multiple cooperative knowledge sources and software using Java/Java Bean and CORBA technologies. The unified user interface of the WebKIDSS provides a cross-platform for distributed users to access to module servers throughout the network. By use of the developed the prototype system, collaborative design can be carried out in an integrated and distributed open environment on the internet/intranet. Based on the preliminary application to the collaborative design of a micro robotic assembly system on the Internet, the developed system indicates some advantages to increase the efficiency of the design coordination and decision-making in the design process. ocess.

In this paper, we propose an integrated approach to analysis and evaluation for STEP-based (STandard for the Exchange of Product model data, officially ISO 10303) electromechanical assemblies. First, two assembly representational models are brought up and elaborated: the EXPRESS/XML schema-based model and the NIST object-oriented UML-based open assembly model (OAM). Then, these two models are integrated, in which the OAM incorporates the EXPRESS/XML schema-based assembly model to completely capture the detailed geometric information. The proposed assembly evaluation approach uses the EXPRESS/XML schema-based model as the information source, and covers not only the geometric and physical characteristics of assembly parts but also the assembly operation data necessary to assemble the parts. The feature of this approach is the linkage of the STEP product definition to the fuzzy analytic hierarchy process for assembly evaluation. The proposed approach has the flexibility to be used in various assembly methods and different environments. A case study shows the feasibility of the proposed approach.

Mass customization has been identified as a competitive strategy by an increasing number of companies. Family-based product design is an efficient and effective means to realize sufficient product variety, while satisfying a range of customer demands in support for mass customization. This paper presents a knowledge decision support approach to product family design evaluation and selection for mass customization process. Here, product family design is viewed as a selection problem with the following stages: product family (design alternatives) generation, product family design evaluation, and selection for customization. The fundamental issues underlying product family design for mass customization are discussed. Then, a knowledge support framework and its relevant technologies are developed for module-based product family design for mass customization. A systematic fuzzy clustering and ranking model is proposed and discussed in detail. This model supports the imprecision inherent in decision making with fuzzy customers' preference relations and uses fuzzy analysis techniques for evaluation and selection. A neural network technique is also adopted to adjust the membership function to enhance the model. The focus of this paper is on the development of a knowledge-intensive support scheme and a comprehensive systematic fuzzy clustering and ranking methodology for product family design evaluation and selection. A case study and the scenario of knowledge support for power supply family evaluation, selection, and customization are provided for illustration.

In this paper we present knowledge of an intensive approach and system for selecting suitable manufacturing processes and materials for microelectromechanical systems (MEMS) devices in concurrent collaborative design environment. In the paper, fundamental issues on MEMS manufacturing process and material selection such as concurrent design framework, manufacturing process and material hierarchies, and selection strategy are first addressed. Then, a fuzzy decision support scheme for a multi-criteria decision-making problem is proposed for estimating, ranking and selecting possible manufacturing processes, materials and their combinations. A Web-based prototype advisory system for the MEMS manufacturing process and material selection, WebMEMS-MASS, is developed based on the client–knowledge server architecture and framework to help the designer find good processes and materials for MEMS devices. The system, as one of the important parts of an advanced simulation and modeling tool for MEMS design, is a concept level process and material selection tool, which can be used as a standalone application or a Java applet via the Web. The running sessions of the system are inter-linked with webpages of tutorials and reference pages to explain the facets, fabrication processes and material choices, and calculations and reasoning in selection are performed using process capability and material property data from a remote Web-based database and interactive knowledge base that can be maintained and updated via the Internet. The use of the developed system including operation scenario, use support, and integration with an MEMS collaborative design system is presented. Finally, an illustration example is provided.

Microelectromechanical systems (MEMS) design and manufacturing are inherently multi-physical and multi-disciplinary; no single person is able to perform a full development process for a MEM device or system. In this paper we develop a WWW-based design platform for collaborative design of MEMS. The proposed web-based distributed object modeling and evaluation framework with client-knowledge server architecture, KS-WebDOME, allows multi-users/designers in different locations to participate in the same design process. Under this framework, concurrent integrated MEMS design and simulation models can be built using both local and distributed resources, and the design collaboration can be realized by exchanging services between modules based upon CORBA standard communication protocol. To facilitate the rapid construction of the concurrent integrated design models for MEMS, a prototype design system, Web-MEMS Designer, is implemented through concurrent integration of multiple distributed and cooperative knowledge sources and software. By use of the developed prototype system, MEMS design and simulation can be carried out simultaneously and intelligently in an integrated but open design environment on the web. The case of a microgripper design for micro-robotic assembly systems is provided to illustrate how designers in different teams and organizations may participate and collaborate in MEMS design.

This chapter first presents a concurrent collaborative design strategy for Micro-Electro-Mechanical Systems (MEMS). Then, it presents the development of a knowledge intensive approach and system to select suitable manufacturing processes and materials for MEMS devices a concurrent collaborative design environment. Fundamental issues on concurrent collaborative design for manufacturability of MEMS and MEMS manufacturing process and material selection such as concurrent collaborative design framework, manufacturing process and material hierarchies, and selection strategy are addressed. A fuzzy decision support scheme for multi-criteria decision-making problem is proposed for estimating, ranking and selecting possible manufacturing processes, materials and their combinations. Based on the client-knowledge server architecture and framework, a web-based prototype advisory system for MEMS manufacturing process and material selection, Web MEMS-MASS, is developed to help the designer find good processes and materials for MEMS devices. The system, as one of important parts of an advanced simulation and modeling tool for MEMS design, is a concept level process and material selection tool, which can be used as a standalone application or a Java applet via the web. The running sessions of the system are inter-linked with web pages of tutorials and reference pages to explain the facets, fabrication processes and material choices, and calculations and reasoning in selection are performed using process capability and material property data from a remote web-based database and interactive knowledge base that can be maintained and updated via the Internet. The use of the developed system including operation scenario, use support, and integration with an MEMS collaborative design system is presented. Finally, an illustration example is provided.

This paper presents the development of an Internet server controller based intelligent maintenance system for products. It also discusses on how to develop products and manufacturing systems using Internet-based intelligent technologies and how to ensure the product quality, coordinate the activities, reduce costs and change maintenance practice from breakdown reaction to breakdown prevention. In the paper, an integrated approach using hardware and software agents (watchdog agent) is proposed to develop the Internet server controller based integrated intelligent maintenance system. The effectiveness of the proposed scheme is verified by developing a real system for the washing machine.

Motion coordination planning and control play a crucial role in robot application to Cartesian task operations with taking into account kinematics and dynamics constraints. This paper presents a unified approach to coordination planning and control for robot position and orientation trajectories in Cartesian space. The concept of generalised robot pose is defined as the robot configuration consisting of position and orientation, in which the orientation is described by a vector equivalent to the rotational angular displacement. The robot pose ruled surface is formed as a three-dimensional motion locus of its configuration vector. The unified treatment of the end-effector positions and orientations is based on the robot pose ruled surface concept and used in trajectory interpolations. The coordination planning of pose trajectories for the robot end effector is accomplished by generating and optimising the pose ruled surface under the constraints of kinematics and dynamics performances. The coordination control is implemented through controlling the motion laws of two end points of the orientation vector and calculating the coordinates of instantaneous corresponding points. The simulation experiment using PUMA 560 robot in arc welding and surface finishing processes are carried out to verify the feasibility of the proposed approach and demonstrate the capabilities of generation and control models.

Assemblability analysis and evaluation play a key role in assembly design, assembly operation analysis and assembly planning. This paper proposes an integrated approach to assemblability analysis and evaluation for STEP (STandard for the Exchange of Product model data, officially ISO 10303) based electro-mechanical products. In the paper, two assembly representation models are first brought up and elaborated: the EXPRESS/XML schema based model and the NIST object-oriented UML-based Open Assembly Model (OAM). These two models are then integrated together; the OAM incorporates the EXPRESS/XML schema based assembly model to completely capture the detailed geometric information. Based on STEP, the proposed assembly evaluation approach uses the EXPRESS/XML schema based model as the information source, and the evaluation structure covers not only the assembly parts’ geometric and physical characteristics but also takes into account the assembly operation data necessary to assemble the parts. The feature of this approach is the linkage of the STEP product definition to the fuzzy analytic hierarchy process (AHP) for assembly evaluation. The proposed approach has the flexibility to be used in various assembly methods and different environments. The case study shows that the proposed approach is feasible.

This paper presents a knowledge-intensive concurrent integration framework for designing, planning, analysis and simulation of assemblies, which is built upon P/T nets and multi-agent systems in AI. In the paper, critical issues are addressed on the implementation of intelligent assembly modeling, analysis and design, planning and simulation using knowledge intensive P/T net models, e.g., knowledge modeling and acquisition, function-behavior-structure modeling, fuzzy relational database, case-based reasoning, and assembly design language, etc. The developed multi-agent intelligent environment, RAPID Assembly system, can process various types of knowledge in assembly design, process and task planning, and assembly system design and simulation so that intelligent design, planning and simulation can be implemented in a virtual environment. It assists designers and manufacturing engineers to design and evaluate the product and its assembly processes and assembly systems (e.g., assembly feasibility, sequences, trajectories, and execution strategies) without building physical prototypes. Design cases are provided to illustrate how the system works.Copyright © 2004 by ASME

Engineering design is essentially a collaborative decision-making process that requires rigorous evaluation, comparison and selection of design alternatives and optimization from a global perspective on the basis of different classes of design criteria. Increasing design knowledge and supporting designers to make right and intelligent decisions can achieve the improvement of the design and design efficiency. This paper develops a knowledge-based decision support model and framework that can be extensively applied for an engineering system, which allows for the seamless / smooth integration of collaborative product development with optimal product performance. The developed hybrid robust design decision support model quantitatively incorporates qualitative design knowledge and preferences of multiple, conflicting attributes stored in a knowledge repository so that a better understanding of the consequences of design decisions can be achieved from an overall perspective. Two new concepts and mechanisms, transforming bridge and regulatory switch, are introduced in integration of decision support models. The results of this work provide a framework for an efficient decision support environment involving distributed resources to shorten the realization of products with optimal life-cycle performance and competitiveness. The developed methodology and framework are generic and flexible enough to be used in a variety of decision problems. Case application and studies for concept evaluation and selection in design for mass customization are provided.

This paper presents an on-going research effort on platform-based product family design using a knowledge intensive support paradigm. The background research related to product family design is first reviewed. Then, the fundamental issues underlying the product family design are discussed. A module-based integrated product family design scheme is proposed with knowledge support for customer requirements’ modeling, product architecture modeling, product platform establishment, product family generation, and product assessment. The systematic methodology and the relevant technologies are investigated and developed for knowledge modeling and support in the product family design process. An information and knowledge-modeling framework is developed for the module-based product family design scheme. The issues and requirements related to develop knowledge intensive support system for module-based product family design are also addressed. Finally, a case study on knowledge support for power supply family design and evaluation is provided for illustration.Copyright © 2002 by ASME

A new collaborative control parameter design strategy is proposed for economic plant control process. The relevance vector machines (RVMs) and genetic algorithms (GAs) are combined to generate the optimal control index table for controllers. More specifically, the probabilistic model based on RVMs is utilised to describe the non-linear behaviours according to the experimental dataset. The evolution-based optimisation model based on GAs is used for collaborative design of the optimum control parameter combinations. A variable-rate fertilising system is presented as an application case for collaborative generation of control index table with the combined accuracy, energy saving and fertilising-consistency optimisation objectives. The experimental results show the effectiveness of the proposed hybrid approach.