Managing modularity in product family design with functional modelingZhang, W.; Tor, S.; Britton, G.
doi: 10.1007/s00170-005-0112-zpmid: N/A
Recent market transition from mass production to mass customization forces manufacturers to develop product families with a common platform to increase design variety, shorten time-to-market, and reduce production costs. This paper presents a new functional modeling approach to support identification of both shared and individual behavioral modules across a family of products for module-based product family design. After separate functional modeling of each product variant, the individual functional models are merged into a single, coherent, and unified family functional model to determine all the shared and individual behavioral modules. The modularity in the family functional model is further explicitly identified using a behavioral modularity matrix of product variants versus behavior. The proposed approach provides a fast method for generating new concept variants during the conceptual design of a family of products. The rationale of managing modularity in product family design with functional modeling is manifested using a modular design example of a family of automatic assembly devices.
Product modeling for multidisciplinary collaborative designLiang, Chen; Guodong, Jin
doi: 10.1007/s00170-005-0108-8pmid: N/A
The paper analyzes characteristics of multidisciplinary collaborative design (MCD) of product and proposes a new MCD-oriented product information model (MCDPM) that integrates physical structure, design semantic and collaboration management data. Better understanding and coordination among the different disciplines can be achieved through the multi-level relations at the semantic level, structure level, and management level. An extended object-oriented method is introduced to represent the MCDPM. As a component and its attributes are all defined recursively in class form, the model can be continually extended and has good modularity, flexibility, and evolution ability. The class inheritance methods in network environment, the concept of discipline view model (DVM) and the method generating the DVM are given. The coordination and consistency maintenance among multiple DVMs is discussed.
An intelligent estimation method for product design timeXu, D.; Yan, H.
doi: 10.1007/s00170-005-0098-6pmid: N/A
The planning and control of product development is based on the pre-estimation of product design time (PDT). In order to optimize the product development process (PDP), it is necessary for managers and designers to evaluate design time/effort at the early stage of product development. However, in systemic analytical methods for PDT this is somewhat lacking. This paper explores an intelligent method to evaluate the PDT regarding this problem. At the early development stage, designers lack sufficient product information and have difficulty in determining PDT via subjective evaluation. Thus, a fuzzy measurable house of quality (FM-HOQ) model is proposed to provide measurable engineering information. Quality function deployment (QFD) is combined with a mapping pattern of “function→principle→structure” to extract product characteristics from customer demands. Then, a fuzzy neural network (FNN) model is built to fuse data and realize the estimation of PDT, which makes use of fuzzy comprehensive evaluation to simplify structure. In a word, the whole estimation method consists of four steps: time factors identification, product characteristics extraction by QFD and function mapping pattern, FNN learning, and PDT estimation. Finally, to illustrate the procedure of the estimation method, the case of injection mold design is studied. The results of experiments show that the intelligent estimation method is feasible and effective. This paper is developed to provide designers with PDT information to help them in optimizing PDP.
Feature signature prediction of a boring process using neural network modeling with confidence boundsYu, Gang; Qiu, Hai; Djurdjanovic, Dragan; Lee, Jay
doi: 10.1007/s00170-005-0114-xpmid: N/A
Prediction of machine tool failure has been very important in modern metal cutting operations in order to meet the growing demand for product quality and cost reduction. This paper presents the study of building a neural network model for predicting the behavior of a boring process during its full life cycle. This prediction is achieved by the fusion of the predictions of three principal components extracted as features from the joint time–frequency distributions of energy of the spindle loads observed during the boring process. Furthermore, prediction uncertainty is assessed using nonlinear regression in order to quantify the errors associated with the prediction. The results show that the implemented Elman recurrent neural network is a viable method for the prediction of the feature behavior of the boring process, and that the constructed confidence bounds provide information crucial for subsequent maintenance decision making based on the predicted cutting tool degradation.
Experimental investigations into forces acting during a magnetic abrasive finishing processSingh, Dhirendra; Jain, V.; Raghuram, V.
doi: 10.1007/s00170-005-0118-6pmid: N/A
A magnetic abrasive finishing (MAF) process is the one in which material is removed in such a way that surface finishing and deburring are performed simultaneously with the applied magnetic field in the finishing zone. Knowledge of forces acting during MAF is important to understand the mechanism of material removal. Forces have direct influence on the generation of a finished surface and accuracy of the workpiece. This paper reports the experimental findings about the forces acting during MAF and provides correlation between the surface finish and the forces. The resistance type force transducer (ring dynamometer) has been designed and fabricated. It is used to measure the normal magnetic force component responsible for microindentation into the workpiece and tangential cutting force component producing microchips. The force data have been recorded on-line by making use of virtual instruments (using Lab-View software). It is concluded that forces and change in surface roughness (ΔRa) increase with increase in current to the electromagnet (or magnetic flux density) and decrease in the working gap.
Practical method to locate the initial weld position using visual technologyChen, Xizhang; Chen, Shanben; Lin, Tao; Lei, Yucheng
doi: 10.1007/s00170-005-0104-zpmid: N/A
The autonomous localization of initial weld position is one of the key technologies to realize intellectualized welding. This paper presented a practical system and method to guide the welding robot to the initial position of the weld seam. Using template matching and polynomial interpolation technology of pixel, the position of initial weld position is located at the sub-pixel level in the image plane. Simple and practical calibration technology avoids the using of complicated algorithms and costly measuring apparatus. Aluminium and its alloys reflect the light strongly, which make the recognition of the weld seam more difficult than steel. Taking the butt joint weld seam of a curve aluminium alloy sheet as an example, the autonomous localization function is realized accurately. For those instances with bigger errors, we advanced a method to rectify the deviation. The welding robot can be guided to the initial position of planar weld seam and meets the requirements to execute welding operation directly. The whole procedure has the characters of simple, practical, and strong anti-jamming.
Rapid prototyping machine based on ceramic laser fusionTang, Hwa; Liu, Fwu; Lin, Wen
doi: 10.1007/s00170-005-0107-9pmid: N/A
This paper proposes an automatic machine using a new process, ceramic laser fusion, for rapid fabrication of ceramic parts. The machine comprises three parts: a laser scanning system, a green layer paving system, and a control system. In order to control the working procedure of layer paving and scanning process, a process computer is connected to an X–Y table, a PLC and a path/laser controller. An even green layer of 0.15 mm thickness could be paved accurately using ceramic slurry by a layer paving device. After drying by an infrared heater, the green layer could be fused to form a ceramic layer by a CO2 laser and then a 3-D ceramic workpiece could be fabricated layer by layer automatically. The time spent on fabricating a 25×25×0.15 mm ceramic specimen was 3 min. The SEM micrograph of the melted ceramic layers shows that ceramic green layers can be fused together.
Nonlinear friction compensation in mechatronic servo systemsMei, Zhi-qian; Xue, Yun-can; Yang, Ru-qing
doi: 10.1007/s00170-005-0113-ypmid: N/A
Friction, especially its nonlinear component, may degrade the tracking performance of robots. Based on Kang’s method, a novel compensation method for nonlinear friction is presented in this paper, which modified Southward’s traditional compensation method for nonlinear friction. The stability of the systems which adopt the novel compensation method is proved with Layapunov’s stability theorem, and is enhanced further. Having estimated the nonlinear friction model using an identification method, the effect caused by its nonlinear component can be compensated, and enhanced tracking performance is verified under the SCARA robot experimental platform using Windows NT and VenturCom’s real-time extension module (RTX) environment.
Investigation of the forward kinematics of the Gough‐Stewart manipulator with natural coordinatesZhao, Jing‐Shan; Yun, Yuan; Wang, Li‐Ping; Wang, Jin‐Song; Dong, Jing‐Xin
doi: 10.1007/s00170-005-0103-0pmid: N/A
In this paper, we propose a forward kinematics model with natural coordinates for the Gough–Stewart manipulator and other spatial parallel mechanisms. The prevailing merits of this model are that the constraint equations are either quadratic or linear and the coordinates are fully Cartesian. As a result, the derivative matrix of the constraint equations only consists of linear or constant elements, which shows remarkable advantages in kinematic and dynamic analysis over those built through the rotation matrix, the elements of which often contain quadratic or transcendental functions. Application examples show that the virtues are obvious in the analysis of the kinematics of spatial parallel manipulators, especially for those with six full degrees of freedom (DoFs), including three translational DoFs and three rotational DoFs. In reality, this method is easily understood and will be widely used in engineering applications.