No description available.

ABSTRACT DESIGN AND CONSTRUCTION OF A SIX DEGREE OF PLATFORM G&uuml / rb&uuml / z, Sarper M.S., Department of Mechanical Engineering Supervisor: Prof. Dr. Tuna BALKAN Co-Supervisor: Prof. Dr. M. A. Sahir ARIKAN November 2006, 83 pages In this thesis a six degree of freedom (DOF) parallel manipulator is designed, developed and simulated virtually. The platform, which is specified and focused on in this thesis, is the specific solution for the generating the required data to simulate a land, airborne or sea vehicle&amp / #8217 / s motion trajectory in the laboratory environment. After explaining the need for such platforms for the military industry, the existing devices will be presented and discussed. Then the design period will be explained while pointing out the key performance criteria. The gathered performance values of the first design iteration will be presented and the modifications done in order to get to the expected performance will be given. Finally an investigation, in order to find the maximum payload that the platform can handle, is performed and presented. It is too hard to get to the desired performance values in mechanical design and manufacturing without using the CAD (Computer Aided Design) and CAM (Computer Aided Manufacturing) programs. In this thesis ProEngineer Wildfire&reg / is used for solid modeling the components, the sub-assemblies and the final assembly, ANSYS Workbench&reg / is used for investigating the modal behavior of the components, ADAMS&reg / 2003 is used for the dynamic simulation of the mechanism, ADAMS/Flex&reg / , ADAMS/AutoFlex&reg / and ADAMS/Durability&reg / are used to analyze the results when flexibility is embedded into the system. At the end of the thesis in Appendix section five technical drawings with the nominal dimensions are given in order to clarify the construction period. By the regulations that must be obeyed in ASELSAN only the nominal dimensions are given in the technical drawings. All the dimensional and geometrical tolerances are given in the approved technical drawings that are proprietary of ASELSAN. Keywords: 6-Axis Motion Platform, Application of CAD and analysis programs, Electromechanical Design, Stewart Platform

The CAREN-Extended system is a fully immersive virtual environment (VE) that can provide stability-challenging scenarios in a safe, controlled manner. Understanding gait biomechanics when stability is challenged is required when developing quantifiable metrics for rehabilitation assessment. The first objective of this thesis was to examine the VE’s technical aspects to ensure data validity and to design a stability-challenging VE scenario. The second and third objectives examined walking speed changes and kinematic strategies when stability was challenged for able-bodied and unilateral transtibial amputees. The results from this thesis demonstrated: 1) understanding VE operating characteristics are important to ensure data validity and to effectively design virtual scenarios; 2) self-paced treadmill mode for VEs with multiple movement scenarios may elicit more natural gait; 3) gait variability and trunk motion measures are useful when quantitatively assessing stability performance for people with transtibial amputations.

This research investigates the Training Effectiveness of a low-cost, PC-based training system when compared with two modes (motion and no motion) of a cab training system with large screen for various aviation flying tasks. While much research on this topic has been done in the past, advances in technology have significantly altered what is considered a "low-cost" "simulator." The technology advances have in effect increased the ability of a "low-cost" "simulator" to deliver desired experiences to the user. These "simulators" often are nothing more than PC training system, with only notional representations of the actual aircraft. This research considers the use of such training systems in training for a highly complex and dynamic task situation, that task being a search and rescue mission. A search and rescue mission is far more complex task than those studied for possible "low-cost" simulation substitution in the past. To address that aspect, one mode of the cab involves motion in two degrees of freedom. The results of this research advances the body of literature on the capability of "low-cost" simulation to deliver the experiences necessary to learn highly complex tasks associated with search and rescue as well as further clarify the extent to which a motion platform aides in flight training. This research utilizes available platforms provided by the US Army Research, Development and Engineering Command Simulation and Training Technology Center. Additionally, all the participants in the research are in training to be helicopter pilots. Participants were randomly assigned to one of three training configurations: a) Cab with motion turned ON, b) Cab with motion turned OFF and c) PC-based simulator. Training effectiveness is evaluated using measures for learning, task performance, and human factors. Statistically significant results are shown for the Cab with Motion and the Cab with No Motion configurations.