Solid State Phenomena Vol. 199

Abstract: The design of a force sensor prototype as an equipment of a control system with force feedback to be used in the RobIn Heart [1,2, telemanipulator system is presented. The main problems with placing the sensor on the laparoscopic tool are discussed. The method of decoupling impact of the gripper actuation force from the measurement is described. Also, the results of computer FEM simulations are shown.

Abstract: The paper presents results of diagnostic tests for a CNC machine tool used for manufacturing elements with restricted freeform surfaces. Some selected errors possible to identify and estimate in numerically controlled machine tools using a QC20-W Ballbar were described and analyzed. The following parameters were subjected to thorough analysis: roundness deviation, perpendicularity and straightness deviation, cyclic error, backlash and reversal spike. The tests made it possible to carry out a correction of selected components of total tool positioning error and their influence on the process of geometric deviations of curvilinear surfaces produced with CNC machine tools.

Abstract: The common measurement error when measuring the component geometrical dimensions using universal contact measurement instruments is caused by different factors, such as error of the measurement instrument, personal reading errors, effect of surface roughness on the measuring line deviation, influence of contact deformation measurement force, and others. The present article examines one of these factors, i.e. contact deformations under the influence of measurement force. To make precise measurements it is essential to find out the effect of roughness of measured components. High roughness creates additional measurement errors. It is particularly important in the measurement of thin components, flexible materials and films, as well as for components with nanocoating. Flexible bodies in the meaning of this article are components of different shape and sizes made of rubber or soft plastic. This article studies principles of error formation based on the deformation of surface roughness and basic material.

Abstract: In the article a construction of a laboratory station for determination of angles in three kinematic pairs of human lower limbs exoskeleton is described. The constructed exoskeleton is supposed to support human lower limbs only on plane vertical to ground. In article the results of measurement of movement parameters of walking human lower limbs obtained using the measuring station. Measurement of angular displacement on the station is realized using six angular displacement absolute transducers. The station is also one of the components contained in lower limb exoskeleton being constructed. The measuring construction will be used to identify actuating systems during exoskeleton construction phase.

Abstract: This presentation deals with a new application of mechatronic means for angle measuring system; it can be applied in precision instrumentation and measurement equipment. Precise angle measuring is based on usage of angle measurement standards such as polygons, precision indexing tables and circular scales. Ring lasers and precision rotary encoders can also be used for this purpose as well as test benches created for angle calibration. Many angular and linear measurement transducers or encoders are used in industry and machine engineering for the position and displacement measurement. The accuracy of angular position fixed by means of these devices reach approximately 0.3" 0.1" (arc second). Control of their accuracy parameters is complicated task consisting from some high requirements needed for rotation, positioning, signal processing, object adjustment and data processing.

Abstract: Stereolithography is an additive rapid prototyping method. This method is based on the principle of solidifying a liquid photopolymer (resin) by laser radiation. Models obtained with this method are characterized by a specific surface structure called stairstep effect. It causes that, the surface should be processed by additional finishing (postprocessing). To minimize the additional machining process, the model should be set in the relation to incremental layers so that the roughness of significant surfaces be optimal.

Abstract: In the paper there is shown the way of increasing the accuracy of the Digital System of Position Measurement with the method of extrapolation.

Abstract: Computer technology has many applications in different fields of industry, health care and medicine. This encompasses paper-based information processing as well as data processing machines (Hospital information system or Clinical information system) and image digitalization of a large variety of medical diagnostic equipment (e.g. computer images of X-ray, MR, CT). The aim of the computer technology in medicine is to achieve the best possible support of patient care, preoperative surgery planning and administration by electronic data processing. At the present time in many countries of the worlds preoperative planning of interventions for lumbar joint is realized with caliper, protractor, plastic templates and x-ray images. Orthopaedic surgeons use transparent template radiographs as part of pre-operative planning in order to gauge the suitability and correct size of an implant. The newly developed CoXaM software offers a simple solution of the problems by using the digital x-ray images and handmade transparent plastic templates. The CoXaM software was developed in Visual Studio 2005 in the Visual C++ programming language at the Department of Biomedical Engineering and Measurement at the Faculty of Mechanical Engineering, Technical University of Kosice. The software was designed for pre-operative planning and helps to determine on the X-ray image a length dimensions, a center of rotation, an angle values. It enables the digitalization of plastic templates from several producers, which will assess the suitability of the type of implant.

Abstract: The article will focus on the presentation of the possibility of practical application of integrated 9-axis sensor, in which magnetic field, acceleration and angular velocity 3-axis sensors were used. Particular emphasis will be placed to describe the mentioned sensors data fusion algorithm, which is necessary for precise and unequivocal determination of the angular position of the tested device. Another presented issue is a selection of an appropriate data filtering algorithm with selected filtering parameters. Additionally, the possibility of implementing described solutions in the angular positions measurement system of cardiosurgical Robin Heart robot master will be shown. Also, a design concept of mentioned robot master along with its working principle will be mentioned.

Abstract: In this paper, tests on Shape Memory Alloy (SMA) wires for use in controlled actuators have been discussed. Selected static and dynamic characteristic curves being the result of experiments were presented in the article. Experiments were conducted at the Dynamics and Control of Structures Laboratory of the AGH University of Science and Technology. Laboratory tests of SMA wires used as actuators have been presented in the paper. Actuators made from the wires contract by about 4-5% of their length when heated, like small muscles, and loosen when cooled. SMA wires used as drives are significantly smaller than traditional solutions using motors or electromagnet to execute work. However, these actuators have flaws, such as strongly non-linear hysteresis. These are main problems in designing actuators, which is why SMA wires are often used in the construction of two-state actuators working as on-off actuators. The problems with SMA wires in their applications as drives are their static and dynamic properties, sensitivity to the environment, poor repeatability of production, non-linearity and hysteresis loop. The tested wires were made from a nickel and titanium alloy; this is an alloy which is often used in drive systems.