13 research outputs found

    From Driving Simulation to Virtual Reality

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    Driving simulation from the very beginning of the advent of VR technology uses the very same technology for visualization and similar technology for head movement tracking and high end 3D vision. They also share the same or similar difficulties in rendering movements of the observer in the virtual environments. The visual-vestibular conflict, due to the discrepancies perceived by the human visual and vestibular systems, induce the so-called simulation sickness, when driving or displacing using a control device (ex. Joystick). Another cause for simulation sickness is the transport delay, the delay between the action and the corresponding rendering cues. Another similarity between driving simulation and VR is need for correct scale 1:1 perception. Correct perception of speed and acceleration in driving simulation is crucial for automotive experiments for Advances Driver Aid System (ADAS) as vehicle behavior has to be simulated correctly and anywhere where the correct mental workload is an issue as real immersion and driver attention is depending on it. Correct perception of distances and object size is crucial using HMDs or CAVEs, especially as their use is frequently involving digital mockup validation for design, architecture or interior and exterior lighting. Today, the advents of high resolution 4K digital display technology allows near eye resolution stereoscopic 3D walls and integrate them in high performance CAVEs. High performance CAVEs now can be used for vehicle ergonomics, styling, interior lighting and perceived quality. The first CAVE in France, built in 2001 at Arts et Metiers ParisTech, is a 4 sided CAVE with a modifiable geometry with now traditional display technology. The latest one is Renault’s 70M 3D pixel 5 sides CAVE with 4K x 4K walls and floor and with a cluster of 20 PCs. Another equipment recently designed at Renault is the motion based CARDS driving simulator with CAVE like 4 sides display system providing full 3D immersion for the driver. The separation between driving simulation and digital mockup design review is now fading though different uses will require different simulation configurations. New application domains, such as automotive AR design, will bring combined features of VR and driving simulation technics, including CAVE like display system equipped driving simulators

    Robotic surgery and planning for corrective femur osteotomy

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    This paper describes a system that assists in the planning and the performing of a surgical action, namely the corrective osteotomy of the thigh bone (femur). The corrective osteotomy of the thigh bone is used for changing the posture of the hip joint. During surgery, a small cross-sectional slice is cut out of the thigh bone by the use of a sawing device. Our system supports the planning phase of this surgery by allowing interactive visualizations of the cutting planes using a 3D surface-oriented model of the thigh bone derived from computer tomography (CT). It also supports the actual surgery, in which a robot hand is steered towards the predetermined cutting planes, a process that is guided and monitored by a vision system

    Comparison of the mechanical properties of low temperature bonded test samples

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    The fabrication of silicon microelectromechanical components (MEMS) involves joining of two or even more wafers. During the last years special focus was given on low temperature waferbonding. In this paper an universal test wafer is proposed that can be applied for bond strength quality monitoring. The investigated wafers in this study were activated, wafer-bonded, annealed at 200°C or 400°C and subsequently tested with respect to dicing yield, tensile strength, fracture toughness, and surface energy. The wafer bonding was performed by seven different partners. It was shown that the bonding quality varied significantly for the different activation technologies even for the same annealing conditions. In general the special treated samples exceed the values of a RCA pre-treated reference sample annealed at 200°C. Some of the activation technologies were able to create bonds that reached the value of RCA pre-treated reference samples, which were annealed at 900°C

    Adaptive fuzzy control for driver assistance in car-following

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    Abstract. An adaptive fuzzy logic controller is described which assists the driver in vehicle speed and distance control by offering a driving strategy via an active accelerator and brake pedal. In order to be accepted by the driver, the behavior of the system called ACC (Adaptive Cruise Control) has to meet the expectations of the human driver to a certain degree. The Fuzzy-ACC provides separate controller components for different driving situations. Each of these components covers a variety of behaviors which is used for the driver adaptation. The Fuzzy-ACC has been implemented in an experimental vehicle and was tested in normal road traffic

    Room temperature bonding of nanostructured silicon wafers and mechanical characterization

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    A new method for bonding of two silicon wafers at room temperature is presented. The technique is based on the interlocking of needle-like structured surfaces. The required nano structure (black silicon) is fabricated using a reactive ion etch process with gas chopping. The needles on the surface have a length of 15-25 µm and a diameter of 300-500 nm with a pitch in the range of their diameters. An external pressure is applied to bond the two aligned wafers at room temperature. The retention force can reach up to 3.8 MPa. Interfacial energy values larger than 2 J/m2 were measured
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