THE CNC VIRTUAL AS TEACHING AND TRAINING AID OF CNC PROGRAMMING

CNC machine tools is the most important practical means of teaching and training of CNC Programming in Vocational High School. Its relatively-high price causes the incapabibilty of the school for getting it, so the teaching of CNC programming in Vocational High School mostly doesn’t use CNC machine. The effect is many students can’t reach the standard competence of applied CNC programming. The unavailability of CNC machine tools in teaching of CNC programming in Vocational High School is treated by using CNC Simulator. The CNC Simulator consist Virtual CNC, and CNC Machine Simulator. It’is a media to simulate of NC Part Program execution..The simulation of NC Part Program execution are displayed tool path a machining process at monitor. NC Part Program has been simulated can be sent to unit control of CNC Machine Simulator. Implementation of CNC Simulator in teaching and training of CNC programming begins from building CNC Virtual. The CNC Virtual is a software which provides a visual effect of environment of CNC machine in the monitor. The building uses Research and Development (R&D) method. Implementation of CNC Simulator in teaching of CNC programming shows; (1) the students are very interested and excited to use the virtual CNC which provides a visual effect of environment of CNC machine in the monitor, actively trying the simulation of numpad virtual in the monitor, inputting data on the panel virtual, and making simulation or execution of the CNC program at CNC Machine Simulator, (2) the students practice to make and execute the CNC programming individually in the classroom or outdoor class. (3) CNC Virtual can be used as teaching and training media classically (in classroom), individually learning, even e-learning

Development of the Compact Jet Engine Simulator From Concept to Useful Test Rig

NASA had a goal to develop a set of modeling tools for designing next generation civil transport aircraft with reduced noise, emissions and increased fuel efficiency by 2016. To verify the models, a database of aerodynamic and acoustic data was needed for an unconventional flying wing design that was predicted to meet the goals. A Compact Jet Engine Simulator (CJES) was needed as the jet source for the 5.8% scale model. Ultra-Compact Combustor Technology from the Air Force Research Laboratory was used to reduce the conventional burner acoustic test rigs down to the required scale size. The Air Force design had to be modified for compactness and safety standards for testing in a wind tunnel. The combustor liner, plug-vane and flow conditioner components were built in-house at the NASA Langley Research Center. The CJES units were built and integrated incorporating a control system for operation in the NASA Langley Low Speed Aeroacoustic Wind Tunnel. The operational envelope of the combustor was mapped, and improvements were developed to moderate combustor instability tones and rig flow noise. The final concept was unchanged, but the internal hardware evolved throughout the process. The Compact Jet Engine Simulator as a standalone unit demonstrated acceptable acoustic rig performance compared to the Boeing Low Speed Acoustic Facility rig. An integrated aerodynamic and acoustic test using the Compact Jet Engine Simulators was performed in the 14- by 22- Foot Subsonic Tunnel in 2012/13, and the results proved the goals were met with a score of 96%. The Compact Jet Engine Simulator is modular and can be used to test subsonic engine nozzles in the bypass ratio range from 5 to 10. The CJES units can be used for acoustic testing or studying the integration of the engine propulsion flow with an aircraft. This thesis focuses on the design and hardware development of the CJES units for which the author was primarily responsible

Prefrontal cortex activation upon a demanding virtual hand-controlled task: A new frontier for neuroergonomics

open9noFunctional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found between the distance traveled by the guided VB and the corresponding cortical activation. These results confirm the suitability of fNIRS technology to objectively evaluate cortical hemodynamic changes occurring in VR environments. Future studies could give a contribution to a better understanding of the cognitive mechanisms underlying human performance either in expert or non-expert operators during the simulation of different demanding/fatiguing activities.openCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, ValentinaCarrieri, Marika; Petracca, Andrea; Lancia, Stefania; BASSO MORO, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentin

Five-Axis Numerical Control Machining of the Tooth Flank of a Logarithmic Spiral Bevel Gear Pinion

In this paper, the production of a logarithmic spiral bevel gear prototype is illustrated by the manufacture of the gear pinion. Firstly, the conical gear body of a logarithmic spiral bevel gear pinion was shaped on a C6140A1 lathe. A kinematic model of a five-axis vertical machining centre DMG DMU40 monoBLOCK, with the position and orientation of each axis relative to the movement of the workpiece, was created. In addition, the processing coordinate transformation formula between the workpiece coordinate system and the cutter coordinate system was devised. The cutter location file was converted to the numerical control code of the DMG DMU40 monoBLOCK. Finally, the pinion of a logarithmic spiral bevel gear was machined on the DMG DMU40 monoBLOCK as a prototype to be used in further research of the logarithmic spiral bevel gear