Motion Planning of an Innovative Serial Robot for Energy Consumption Reduction With “On Fly” Pieces Grasping

The following study deals with the on-line motion planning of an innovative SCARA like robot with unlimited joint rotations. The application field is the robotic interception of moving objects randomly distributed on a conveyor and detected by a vision system. A motion planning algorithm was developed in order to achieve a satisfactory cycle time and energy consumption. The algorithm is based on the evaluation of the inertial actions arisen in the robot structure during the pick and place motions and it aims to keep constant the rotation velocity of the first joint during the motion, the grasping and the discarding phases. Since the algorithm must be applied run time and the number of the reachable pieces can be high, a particular care was dedicated to the computational burden reduction. Subsequently to an analytic study of the kinematical constraints and the criteria definition for the choice of which piece to grasp, a devoted simulation software was developed. The software allows the control and the evaluation of the effects of all the main parameters on the system behavior and a comparison of the cycle time and the energy consumption between the proposed algorithm and a standard point-to-point motion strategy.

Improvement of Integrity Concepts for NPP Primary Circuit Piping

Operating NPPs license extension activities in Russia produced strong demand for safety improvement of plants build according to earlier standards. Installation of additional supports as pipe whip restraints is one of requirement in acting regulatory documentation which should be followed or compensated by appropriate measures like Leak Before Break (LBB) analyses and improvement of In-Service Inspection (ISI) and Leak Detecting System (LDS). Basic document for LBB concept application to Russian NPP piping is RD 95 10547-99. Its requirements correspond to classical LBB principles used in many countries in Europe, USA and Japan. In many real cases requirements of RD 95 10547-99 could not be applied to safety important NPP piping systems due to the presence of specific features of operational degradation due to some corrosion mechanisms: for example, erosion-corrosion (E-C) for carbon steel piping and intergranular stress corrosion cracking (IGSSC) for heat affected zones of austenitic piping weldments. For special case of RBMK piping with outer diameter 325 mm (potentially susceptible to IGSCC) special Break Preclusion Concept has been developed in Russia after IAEA Extrabudgetary Program in 2000–2002. Contrary to LBB Concept demanding for all four basic principles to be completely fulfilled BP Concept accepts some principles to be fulfilled in a balanced way with demonstration of monitored degradation effectively achieved in operation. Special BP Concept is being developed now to support integrity assessment of RBMK carbon steel steam and feed water piping potentially susceptible to E-C which requires another set of measures to demonstrate principle of controlled degradation in operation then in case of austenitic steel piping. General scheme of piping integrity analyses according to LBB and BP Concepts is discussed and examples of specific approaches to achieve controlled degradation are illustrated in paper. As result of LBB and BP Concepts application it is possible to substantiate reject of additional piping whip restraints implementation on-site. Examples of similar safety methodology development in other countries have been reported at IAEA Specialists Meeting on LBB in Kiev, Ukraine in November 2006.

Boiling of Water and Surfactants in Confined Space

Natural convection boiling of water and surfactant solutions at atmospheric pressure in narrow horizontal annular channels was studied experimentally. The Alkyl (8–16) Glucoside with molecular weight of 390 g/mol was used in the experiments. It is a nonionic surfactant with negligible environmental impact. The length of the horizontal channels was 24 mm and 36 mm, the gape size was in the range of 0.45–3.7 mm, the heat flux was in the range of 20–500 kW/m2, the concentration of surfactant solutions was varied from 10 to 600 ppm. The gap size of the vertical channels was changed in the range of 1–80 mm. The flow pattern was visualized by high-speed video recording to identify the different regimes of boiling of water and surfactant solutions with different concentrations. At heat flux q<100 kW/m2 the rapid growth of elongated bubble was observed in the water. The rapid bubble growth pushes the liquid-vapor interface on both open sides of the channel. When a bubble departs from a nucleus cavity, its cavity is then recovered by liquid, and next bubble will appear on the heated tube after a certain interval. The behavior of the long vapor bubbles occurring in small size annular channels is not similar to annular flow with intermitted slugs between two vapor trains. Surfactant solution promotes activation of nucleation sites in a clustered mode. The cluster contains a number of small bubbles, the location of nucleation sites and time behavior of each bubble cannot be traced exactly. At higher values of heat flux coalescence process was observed during boiling of water and surfactant solutions. For water boiling in horizontal channels at Bond numbers Bo<1 the CHF in restricted space is lower than that in unconfined apace. This effect increases with increasing the channel length. For water at Bond number Bo = 1.52, boiling can be considered as unconfined. Additive of surfactant led to enhancement of heat transfer compared to water boiling in the same gap size, however, this effect decreased with decreasing gap size. For the same gap size, CHF in surfactant solutions was significantly lower than that in water. Hysteresis was observed for boiling in degraded surfactant solutions.

Seepage Regime in Canyon Mass With Influence of Water-Storage Reservoir Impoundment Speed

Generally, most waterpower plants have to function under energy system peak load operation. Thus, there is a relatively quick water level variation observed in water-storage reservoirs, which contributes to the problems, especially in case of high-pressure waterworks facilities. Swift reservoir draw-down enhances seepage volumetric forces acting from the rock mass, which may lead to rock mass cracking and eventually to the development of landslide processes. A rapid impoundment of the water-storage reservoir is no less damaging. In this case, seepage in the rock mass is progressing in non-steady conditions, there occurring, in the inception stage: - high magnitude seepage hydrodynamic forces at the rock mass surface, creating additional loads on the rock mass, causing deflection of its surface, which may promote dam-foundation contact opening; - with increased pore pressures and seepage gradients, there may occur suffusion and other undesirable processes in the rock mass. In the work is given a numerical analysis of some parameters of seepage mode given based on right-bank investigation admitting presence of break in the dam filling-up mode. Options of time-intervals for the two basic versions – in case of sudden rising of water level in the upstream and in case of slow filling-up and setting up steady-state seepage mode in the massive – are being discussed. Determination of seepage flow parameters (including gradients) requires nonstationary field task to be solved. Finite-elements approximation for time analysis of the task is solved by finite-difference scheme. Seepage calculations are carried out by cyclic-iteration scheme – where volumetric water content, hydraulic conductivity and elasticity module determined numerically by functional relations. The subject of research is Enguri waterpower plant arch dam, at present the highest in the world (Georgia, height 271.5m, fig. 1.1). Consideration is being given to a variety of cases: - canyon slope in the zone of major geological fracture; - foundation in the central part of the dam.

Integral PLM Solution to Product Development Challenges and Supporting Technologies

Product development today is more complex and more difficult than ever. Manufacturers face significant challenges understanding the full impact of changes proposed at various stages of development, and demand for collaboration is at an all-time high. At the same time Product Development differs from Manufacturing in that the objective is to create a digitally validated representation of the product and manufacturing processes, rather than physical product. The flow of digital product and process information between the different stakeholders involved in product development is critical to the performance of product development processes. The main challenge is to create and communicate this information with minimum waste. Product Lifecycle Management (PLM) offers the solution from planning to support, across all applicable departments, and throughout the entire supply chain. By working with complete digital product representations, teams can quickly experiment, make changes, perform what-if scenarios, refine designs, and more. Technologies supporting product development processes notably define and impact the information flow. When product development technologies involve multiple point solutions that manage independent views of the digital Product (i.e., the MCAD view, the BOM view, the cost view) it is nearly impossible for various users to piece together a consistent picture or maintain integrity between the views. Product development environment with multiple disconnected tools and databases that house different information product is still common. There are many barriers to information transfer and availability — and as a result there is little information flow. At a high level, an integral product development system, a single source of truth for product data whose components are designed to work together seamlessly, can greatly streamline information flow. Information fidelity is not compromised, and as a result information flows rapidly and consistently. PTC’s Product Development System (PDS) represents such integrated PLM solution that manages interdependencies across all forms of product information, so that everyone on the team can easily understand how their input impacts the overall product. There are key process principles or initiatives that a company may choose to focus on to reduce waste in product development: front loading, visual planning and tracking, standardizing work, systematic knowledge capture and reuse, closer manufacturing and supplier partnering, and improving the efficiency of review or collaboration activities. This lecture is going to focus on making the connection with relevant technologies that can play a critical supporting role, and on software components of Product Development System representing corresponding technology enablers.

Digital Imaging Exposure-Time Optimisation of Tripod-Camera Vibrating Systems Based on MTF

The problem of exposure-time optimization in digital images acquired by a tripod-camera vibrating system is examined in this paper and an initial analysis is presented. The different noise sources concerning both the acquisition sensor in the camera and external vibrations were studied and quantified in some specific cases. The digital image quality is then discussed in terms of the MTF function evaluated at 50% level in order to define what the optimum ranges of exposure-times are.

Rotating Shafts Affected by Transverse Cracks: A Sensitivity Analysis

The dynamic behaviour of heavy, horizontal axis, rotating shaft-lines affected by transverse cracks can be analysed in the frequency domain by a quasi linear approach, using a simplified breathing crack model applied to a traditional finite element model of the shaft-line. This allows to perform a series of analyses with affordable efforts. The analysis of the modelling procedure allows to define an approximated approach for simulating the dynamical behaviour, which allows to predict the severity of the crack excited vibrations, combined to modal analysis. this answers to the old-age question on how deep a crack must be to be detected by means of vibration measurements. The model of a 320 MW turbo-generator group has been used to perform a numerical sensitivity analysis, in which the vibrations of the shaft-line, and more in detail the vibrations of the shafts in correspondence to the bearings, have been calculated for all possible positions of the crack along the shaftline and for two different values of the depth of the crack. The calculated results confirm the predicted behaviour.

Large Angle Parametrically Excited Tilting Micro Actuator

We present novel operational principle of a tilting MEMS device based on parametric excitation and linear to angular motion transformation. The device is fabricated using a single layer of silicon on insulator (SOI) wafer and combines simple fabrication process with several beneficial features including large tilting angles, wide bandwidth, low sensitivity to deviation in geometrical and operational parameters and low actuation voltage. A theoretical feasibility and performance study was carried out using a lumped model of the device and verified by a coupled three-dimensional simulation. Parametric excitation of the tilting motion was demonstrated experimentally using and external piezoelectric transducer and tilting angles of 39° were registered. The suggested operational approach could be efficiently implemented in many MEMS based applications incorporating tilting elements including micromirrors, bio medical devices and inertial sensors.

MBARS2: A New Design for a 3- Degrees of Freedom Parallel Structure for Joint Arthroplasty

In this report we present the second prototype of a 3-degrees-of-freedom active, miniature bone-attached, robotic system. The report focuses on the mechanical structure, workspace analysis and inverse kinematics solution. The robot is capable of preparing the bone cavity for an implant during joint arthroplasty procedures. This system, just as its predecessor is image-free and all planning is performed intraoperatively in the robot coordinate system, eliminating the need for external tracking systems in the OR. Experiments were conducted using the first robot prototype to evaluate its accuracy and the results supported the feasibility of the concept.

Freedom of Micro Manufacturing Tool-Free Series Production in Industrial Applications of Micro- and Nanotechnology

RMPD®, which stands for Rapid Micro Product Development, is a family of technologies designed to generate with a parallel batch process, microstructures, microsystems and/or MEMS or MOEMS in a parallel batch process. Photo polymerized monomer, oligomere and hybrismaterial (sol-gel) polymerized with uv-light and generate the system. The technology’s 3D-CSP (tree dimensional chip sice packaging), RMPD®-multimat (volume specific material propertys), RMPD®-stick2 (mechanical parts directly to a foil, wafer and so on) and RMPD®-nanoface (surface roughness in sub-nm range) have since 1996 been key elements in this worldwide-patented family of technologies, which has allowed System in Packing SiP to develop into a virtually tool-free production process. Additive and parallel processes give these technologies a costefficient and customer oriented strategic direction.