Applied Mechanics and Materials Vol. 772

Abstract: The performance improvement in Electrical Discharge Machining process is a tedious one in materials and manufacturing processes especially in making of complex die and moulds. Due to non linear nature of this process, conventional pulse generators such as RC pulse generator and transistor pulse train generator cannot produce uniform energy distribution. Since RC pulse generator can produce smaller crater volume, it can make better surface finish than transistor pulse train generator crater size is influenced by the discharge current produced during the machining process. Due to its stochastic behavior, the discharge current is varied for every spark. The modified iso current pulse generator can produce uniform energy distribution with smaller crater size. In this study, EDM drilling experiments have been conducted on AISI 304 stainless steel with the RC pulse generator, Transistor pulse generator and iso energy pulse generator in electrical erosion process. The effects of these pulse generators on surface characterization have been evaluated and analyzed. From the evaluation results, it has been detected that the iso energy pulse generator has produced better surface structure than conventional pulse generators.

Abstract: Voiding in solder joints poses a serious reliability concern for electronic products. The aim of this research was to quantify the void formation in lead-free solder joints through X-ray inspections. Experiments were designed to investigate how void formation is affected by solder bump size and shape, differences in reflow time and temperature, and differences in solder paste formulation. Four different lead-free solder paste samples were used to produce solder bumps on a number of test boards, using surface mount reflow soldering process. Using an advanced X-ray inspection system void percentages were measured for three different size and shape solder bumps. Results indicate that the voiding in solder joint is strongly influenced by solder bump size and shape, with voids found to have increased when bump size decreased. A longer soaking period during reflow stage has negatively affectedsolder voids. Voiding was also accelerated with smaller solder particles in solder paste.

Abstract: Progressive replacement of traditional tools with intelligent technological equipment becoming more complex is one of the most important aspects of the development of production processes in all industrial fields. Intelligent measurement and integrated dimensional control are needed to ensure the quality of the product or industrial manufacturing process, whatever the field. Because the automotive industry is one of the most important industries in the world, manufacturing systems engineering, control methods and techniques, and assurance of quality, present particular interest by the economic results, in particular the reduction of working time and production costs. In a perfect world or in an integrated production environment, the new 3D measurement systems, by providing the quality control integrated into the production line would be able to measure all the necessary parameters in a single step, without errors and render the results in the same way to the manufacturing networks with computers, in formats useful for CNC machines control and process management.

Abstract: The research presented in this paper aims to review the theoretical and practical approach for one of method to create the interface, to condition and to gather the data from the resistive force tactile sensor, in for the measuring of the vertical reaction force to the ground during human walking. The project result is a portable electronic system which allows the gathering, storing and transmission of the data from the force sensors mounted in an “overshoe” holder [1]. The article presents the research methods for the measured parameters as vertical reaction force to the ground, measured in 10 contact points between the foot sole and the ground by the help of some tactile sensors. The paper analysis all issues related to providing an optimal solution for the support with sensors and presents the conclusions for practical design.

Abstract: By addressing and developing Intelligent Adaptronic Engineering, with the view to widening towards fundamental and applied knowledge of the science and engineering of Adaptronics, in the direction of design and construction of intelligent adaptronic solutions and transferring of research results towards industry and economy, is created the synergistic vector of the intelligent specialized field, to support the sector and support the development of the sector, of the industry and economy and the current informational society and post-informational society.This paper deals with the scientific concepts, achievements and experiments on intelligent mechatronic equipment and system in adaptronic architectures for monitoring, control, service and remote maintenance in the automotive industry.

Abstract: The paper presents a stage of the research concerning the development and improvement of a low cost small flexible coordinate measuring machine (CMM) that could be used in the future both in research and industry. Its main advantage could refer to the low cost (only about 30 ÷ 40% of the cost of a CMM in the category on the market, having similar dimensions) in conditions of high performance criteria. This could be possible due to the fact that they were implemented some recycled components in the construction of the robotic drive axes of the machine structure, low cost scanning devices and low cost mechanical systems for fixing and adapting the scanning devices. The research stage presented in the paper is essential for the later stages of research to develop an integrated concept: low-cost, flexibility, precision and efficiency, all criteria referring to a small portable scanning CMM, with possible application in any domain. Specifically, the described research stage refers to evaluate the implementation of some scanning systems, type non-contact low-cost and modern displacement transducers, on the principle of emission of LASER radiation, in terms of scanning accuracy. The reason is that currently these systems are used more and more in the CMMs construction.

Abstract: The article describes the synthesis of the connecting system for mechatronic modules SCHUNK PowerCube PR70, PR90 and PW90. Emphasis is placed on enabling the quick reconfiguration of the kinematic structure of the manipulator for a mobile robotic system built from these modules. The article describes the process of synthesis of mechanic components of the system, hardware and software ensuring the necessary functions for the realization of connections, detection of orientation of the connected module, securing the flow of energy and data signals and the appropriate response in the control application of the system. This is substantiated by evaluating tests realized on produced prototypes of connecting systems. The article also describes a future outlook for further developments of the connecting system.

Abstract: The paper presents an original solution of hydraulic proportional directional control valve with planar distribution and differential control. The characteristic of the flow section is established and an example of such directional control valve integrated in the structure of a hydraulic positioning system with mechanical feedback is given.

Abstract: The aim of this study was to determine the workspace of surgeon's body for designing more efficient surgical robots in the operation rooms. Five wearable inertial sensors were placed near the wrist and elbow joints and also on the thorax of surgeons to track the orientation of upper limb. Assuming that the lengths of five segments of an upper limb were known, measurements of the inertial sensors were used to determine the position of the wrist and elbow joints via an established kinematic model. subsequently, to assess the workspace of surgeon upper body, raw data were collected in the arthroscopy and laparoscopy operations. Experimental results demonstrated that the workspaces of surgeon's joints are limited and predefined. The results can be used for designing surgical robots and surgeon body supports.

Abstract: The paper presents an original pneumo-hydraulic system that controls the speed and the position of the actuated load by using a hydraulic circuit containing a hydraulic proportional throttle. A mathematical model of the solution is developed and numerical simulations are performed. The experimental results obtained on the built model confirm the theoretical ones.