Semi-autonomous manufacturing systems: The role of the human–machine interface software and of the manufacturing tracking software

This technical paper discusses the advantages of implementing semi-autonomous manufacturing systems. The paper reports the development of two robotic cells designed with the objective of being almost autonomous, requiring only minor parameterization to operate efficiently. This objective can be obtained by proper design of the human–machine interface (HMI) software and of an efficient connection to the production tracking software. The two presented robotic systems explore these two aspects giving to the reader a good insight into the problem. The discussion will be kept general in a way to allow readers to easily explore from the ideas presented in the paper.     

An integrated software system for hybrid flight simulation: The boeing hybrid simulator

The Boeing Hybrid Simulator is a general-purpose hybrid computer designed to provide a laboratory for the development of hybrid methods of solving a variety of aero-space problems as well as to support large-scale simulations. The first such simulation is a Flight Simulation Program which provides both a three-degrees-of-freedom missile performance analysis tool and a six-degrees-of-freedom missile subsystem design analysis tool. The 3D simulation was implemented by placing the integrations of the translational equations on the analog, utilizing the digital for function generation, some algebraic manipulations, and basic bookkeeping. The 6D was implemented by placing the integrations of the rotational equations on the analog and the integrations of the translational equations on the digital. Phase control was supplied on the analog in both cases. A hybrid oriented execute-time monitor system supported the simulations by 1) providing a flexibile man-machine relationship, 2) providing an automatic and manual control capability, and 3) reducing digital and analog setup time. It enabled the man at the console to bring system packages into computer memory either to temporarily displace the simulations or to tie in with them in such a way that activities closely related to the execution of the simulations occur at the end of frame calculations.     

Behavioral modeling, simulation and synthesis of multi-standard wireless receivers in MATLAB/SIMULINK

This paper presents a SIMULINK block set for the behavioral modeling and high-level simulation of RF receiver front-ends. The toolbox includes a library with the main RF circuit models that are needed to implement wireless receivers, namely: low noise amplifiers, mixers, oscillators, filters and programmable gain amplifiers. There is also a library including other blocks like the antenna, duplexer filter and switches, required to implement reconfigurable architectures. Behavioral models of building blocks include the main ideal functionality as well as the following non-idealities: thermal noise, characterized by the noise figure and the signal-to-noise ratio, and non-linearity, represented by the input-referred second-order and third-order intercept points, IIP₂ and IIP₃, respectively. In addition to these general parameters, some block-specific errors have also been included, like oscillator phase noise and mixer offset. These models have been incorporated into the SIMULINK environment making an extensive use of C-coded S-functions and reducing the number of library block elements. This approach reduces the simulation time while keeping high accuracy, which makes the proposed toolbox very appropriate to be combined with an optimizer for the automated high-level synthesis of radio receivers. As an application of the capabilities of the presented toolbox, a multi-standard direct-conversion receiver intended for 4G telecom systems is modeled and simulated considering the building block requirements for the different standards.     

Multi-physics modeling in virtual prototyping of electronic packages––combined thermal, thermo-mechanical and vapor pressure modeling

The realization of virtual prototyping of electronic packages depends on the capability and reliability of multi-physics modeling. This paper focuses on the methods and solutions of combined thermal and thermo-mechanical modeling. The package-level thermal behaviors for various kinds of packages are discussed first through the thermal simulation. The impact of internal package design on thermal performance is highlighted. Then the methods and solutions of combined thermal and thermo-mechanical modeling are addressed in detail. The strong interactions of thermal and mechanical simulations, as well as the trade-off between thermal and mechanical designs are discussed through two case studies. The benefit of moisture behavior modeling for the package design is also briefed in this paper.     

The role of computer modeling and simulation in electric and hybrid vehicle research and development

Computer modeling and simulation is widely used in support of electric and hybrid vehicle research and development. Many modeling-assisted studies and assessments, involving candidate technology comparisons, have been performed to provide information for management planning and research decisions. Modeling has also been extensively used in engineering activities including preliminary and final design optimization. A wide range of programs has been developed including small ones for use on hand-held programmable calculators and large programs involving more than 11 000 lines. Many programs exist in the public domain, and two major programs are available on commercial time-sharing systems.     

The study on failure mechanisms of bond pad metal peeling: Part A––Experimental investigation

For the experimental investigation on failure mechanisms of bond pad metal peeling, 31 failed SDRAM chips after the pad peeling are gathered, and SEM and FIB are utilized. From the results of this study, the vertical tension loading transferred by the capillary to the deformed ball is recognized as the direct driving force for the pad peeling and the crack on the bonding pad as well as its propagation into the oxide layers under the pad is identified as the direct cause of the pad peeling. Moreover, the propagation of the crack along the interface of the layers under the pad is explained as the initiation of ‘ductile fracture type failure’, which can be considered as a possible cause of the pad peeling. A schematic diagram for the process of the pad peeling is constructed based on the results of this research and the effect of the probe test on the pad peeling is also investigated to confirm the result of Hotchkiss et al. [Proceedings of the 51st Electronic Components and Technology Conference, 2001, p. 1175].     

The study on failure mechanisms of bond pad metal peeling: Part B––Numerical analysis

According to the results of Part A of this paper [Microelectron. Reliab., this issue], the vertical tension loading transferred from the capillary is clarified as the direct driving force for bond pad metal peeling. Furthermore, the crack on the bonding pad is identified as the direct cause of the pad peeling. However, the major driving force for the crack that is correlated to the four main loadings described in the part A of this paper is not clarified. In order to find the driving force for the crack, whole ball bonding process of ultrasonic wire bonding is simulated by finite element method. The results of this study indicate that the horizontal vibration of the capillary controlled by ultrasonic power of the bonding machine has the most serious effect on the crack on the bonding pad as well as its propagation into the oxide layers in SDRAM chip. Thus it can be the major driving force for the crack.     

Halftone banding reduction for a class of electrophotographic systems – Part I: Characterization and modeling

This paper proposes new insights and methodologies that complement existing techniques for characterizing and modeling halftone banding, an artifact of periodic light and dark bands across a printed image perpendicular to the print direction, for a class of electrophotographic (EP) systems, which is commercially known as laser printers. For characterizing banding based on transmission error measurement, specific frequency-domain signal processing, i.e., order analysis, was applied to help identify possible disturbance sources with certain gear components. For characterizing banding based on absorptance measurement on printed images, it was pointed out that a good metric should incorporate appropriate nonlinear operator that characterizes the human visual system. This proposition was supported by simulation results obtained from a three-stage visual model. For modeling banding, a more comprehensive EP model was developed to include transmission parameters such as laser scanning frequency, gear dimension, and angular velocity. Simulation study was performed on the simplified version of the derived model, which demonstrated close correlation between halftone banding and transmission quality. This motivates control of the motor/gear transmission system for reducing banding artifact in EP processes.     

Substrate noise generation in complex digital systems: efficient modeling and simulation methodology and experimental verification

More and more system-on-chip designs require the integration of analog circuits on large digital chips and will therefore suffer from substrate noise coupling. To investigate the impact of substrate noise on analog circuits, information is needed about digital substrate noise generation. In this paper, a recently proposed simulation methodology to estimate the time-domain waveform of the substrate noise is applied to an 86-Kgate CMOS ASIC on a low-ohmic epi-type substrate. These simulation results have been compared with substrate noise measurements on this ASIC and the difference between the simulated and measured substrate noise rms voltage is less than 10%. The simulated time domain waveform and frequency spectrum of the substrate noise correspond well with the measurements, indicating the validity of this simulation methodology. Both measurements and simulations have been used to analyze the substrate noise generation in more detail. It has been found that direct noise coupling from the on-chip power supply to the substrate dominates the substrate noise generation and that more than 80% of the substrate noise is generated by simultaneous switching of the core cells. By varying the parameters of the simulation model, it has been concluded that a flip-chip packaging technique can reduce the substrate noise rms voltage by two orders of magnitude when compared to traditional wirebonding.     

Language identification of controlled systems: modeling, control,and anomaly detection

Formal language techniques have been used in the past to study autonomous dynamical systems. However, for controlled systems, new features are needed to distinguish between information generated by the system and input control. We show how the modeling framework for controlled dynamical systems leads naturally to a formulation in terms of context-dependent grammars. A learning algorithm is proposed for online generation of the grammar productions, this formulation then being used for modeling, control and anomaly detection. Practical applications are described for electromechanical drives. Grammatical interpolation techniques yield accurate results, and the pattern detection capabilities of the language-based formulation makes it a promising technique for the early detection of anomalies or faulty behavior     

A charge-modulated FET for detection of biomolecular processes: conception, modeling, and simulation

A novel, solid-state sensor for charge detection in biomolecular processes is proposed. The device, called charge-modulated field-effect transistor, is compatible with a standard CMOS process, thus allowing fully electronic readout and large scale of integration of biosensors on a single chip. The detection mechanism is based on the field-effect modulation induced by electric charge changes related to the bioprocess. A model of the device was developed, to provide a manageable relationship between its output and geometric, design and process parameters. Extensive two- and three-dimensional simulations of the proposed structure validated the model and the working principle.     

An almost comprehensive approach for the choice of motor and transmission in mechatronics applications: Motor thermal problem

This paper deals with the choice of motor and transmission in mechatronic applications by means of an approach in which all the following aspects related to the transmission are taken into account from the outset: the limits of speed and torque of the transmission; the alternation in the reference task of direct and inverse efficiency of the transmission, which can also be functions of the motor speed; the transmission inertia. In this paper only the continuous duty operating range of the drive system is considered. The method is based on the determination of the motors that can be coupled with a given transmission and is explained by means of resolving diagrams. The guidelines of an automatized procedure for the determination of the admissible drive system-transmission couples are traced and a case study is presented.     

Design,simulation, and implementation of an integrated,hybrid photocurrent-to-digital converter in CMOS technology

This article presents a design, modeling, simulation, and measurements of a hybrid photocurrent-to-digital converter integrated together with photo-diodes in a 130 nm CMOS process, without any additional process steps. Photo-currents of integrated photo-diodes with different responsivities to different wavelength of the light and light intensity are converted into 22-bits digital results in 2 ms. The results can then be converted into CIE XYZ or RGB color luminosity space using dedicated DSP algorithm. A high resolution, hybrid, ADC converts light induced photo-currents into 22-bit digital results, canceling the dark current of the photodiodes and 1/f noise and offset voltage of the input stage of the modulator. The whole converter consumes on average less than current at supply voltage at 10 conversions per second. It occupies approx. 0.8 mm² of silicon area, including the three photodiodes, a multiplexer, and the ΣΔ modulator.     

PSIM-based modeling of automotive power systems: conventional, electric, and hybrid electric vehicles

Automotive manufacturers have been taking advantage of simulation tools for modeling and analyzing various types of vehicles, such as conventional, electric, and hybrid electric vehicles. These simulation tools are of great assistance to engineers and researchers to reduce product-development cycle time, improve the quality of the design, and simplify the analysis without costly and time-consuming experiments. In this paper, a modeling tool that has been developed to study automotive systems using the power electronics simulator (PSIM) software is presented. PSIM was originally made for simulating power electronic converters and motor drives. This user-friendly simulation package is able to simulate electric/electronic circuits; however, it has no capability for simulating the entire system of an automobile. This paper discusses the PSIM validity as an automotive simulation tool by creating module boxes for not only the electrical systems, but also the mechanical, energy-storage, and thermal systems of the vehicles. These modules include internal combustion engines, fuel converters, transmissions, torque couplers, and batteries. Once these modules are made and stored in the library, the user can make the car model either a conventional, an electric, or a hybrid vehicle at will, just by dragging and dropping onto a schematic blank page.     

Long-term base current instability in AlGaAs/GaAs HBTs: physical mechanisms, modeling, and SPICE simulation

This paper provides an overview of the long-term base current instability in the AlGaAs/GaAs heterojunction bipolar transistor (HBT), which is a main mechanism governing the HBT long-term current gain drift and thus a major concern for the HBT reliability. Topics covered include: (1) types of base current instability and their underlying physical mechanisms; (2) leakage currents in the HBT and their relevance to the reliability; (3) electrothermal interaction and their impact on the HBT reliability; (4) analytic model for predicting the HBTs mean time to failure (MTTF); and (5) SPICE implementation and simulation of HBT circuit reliability. Measurements and device simulation results are also included in support of the modeling and analysis.     

C4ISR系统的建模方法与仿真环境研究

针对C^4ISR这类复杂大系统，主要对两个问题进行了探讨：一个是建模方法的研究，在分析比较几种常用方法的基础上提出了拓展UML—OPN方法，并作了简单的描述；另一个是对基于HLA的C^4ISR仿真系统环境的研究，阐述了其功能需求和仿真环境的设计要点。     

Langmuir–Blodgett films of indandione-l,3 pyridinium betaine. II: Molecular structure and properties of monolayers; simulation and optical absorption data

The molecular structure and optical properties of a monolayer at the air/water interface of novel amphiphilic derivatives of indandione-1,3 pyridinium betaine (IPB) with different lengths of the aliphatic tail, namely C_1lIPB and C₁₇IPB, have been studied using optical absorption techniques and computer simulation approaches. The compression π-A isotherm of the C₁₇IPB monolayer and computer simulation of its molecular structure show that there may exist two energetically stable molecular configurations, one with antiparallel orientation of the dipole moments of the C₁₇IP ‘heads’ in the low-pressure region at π = 5–32 mN m^?1 and the second (after a distinct phase transition at π = 33 mN m^?1) with parallel orientation of the dipoles, with different tilt angles and areas per molecule. For C₁₁IPB only the first structural phase is observable. The compression-induced changes in spectral characteristics of the two structural phases go in diametrically opposite directions. In the low-pressure phase compression induces a red shift and an increase in intensity of the S₁ absorption band, while in the high pressure phase a blue shift and a decrease in the intensity of this band are observed. These spectral changes correlate reproducibly with the compression π-A isotherms. Measurements of absorption dichroism confirm the change in the tilt angle at the phase transition pressure. The compression-induced spectral changes have been substantiated by the results of quantum chemical calculations.     

An integrated theory of whisker formation: the physical metallurgy of whisker formation and the role of internal stresses

Over 50 years of whisker research (cadmium, zinc, and tin) has not resulted in consensus about whisker formation fundamentals for metal films. New analytical tools have recently provided new insights into microstructural changes that occur during whisker formation. Integration of these newer observations with historical data led the authors to propose an Integrated Theory of Whisker Formation. The Integrated Theory incorporates physical attributes such as microstructure and internal stress states. Particular emphasis is placed on recrystallization, grain boundary diffusion, film-substrate interdiffusion (i.e., the Kirkendall effect), and stress gradients. The Integrated Theory does not require dislocation mechanisms for material transport to the whisker location. Material is transported to a whisker grain by the surrounding grain boundary network under the driving impetus of positive stress gradients. Transported atoms then move from the grain boundary network into the whisker grain. This movement into the whisker grain pushes the free surface of the whisker grain upward and, thereby, grows the whisker structure.