10 research outputs found

    New applications of Spectral Edge image fusion

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    In this paper, we present new applications of the Spectral Edge image fusion method. The Spectral Edge image fusion algorithm creates a result which combines details from any number of multispectral input images with natural color information from a visible spectrum image. Spectral Edge image fusion is a derivative–based technique, which creates an output fused image with gradients which are an ideal combination of those of the multispectral input images and the input visible color image. This produces both maximum detail and natural colors. We present two new applications of Spectral Edge image fusion. Firstly, we fuse RGB–NIR information from a sensor with a modified Bayer pattern, which captures visible and near–infrared image information on a single CCD. We also present an example of RGB–thermal image fusion, using a thermal camera attached to a smartphone, which captures both visible and low–resolution thermal images. These new results may be useful for computational photography and surveillance applications. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    On Objective Measures for Ride Comfort Evaluation

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    An essential tool in the truck development process is the ability to quantify and grade vehicle dynamic behavior. Today this is performed either through subjective or objective tests. Subjective tests have the disadvantage that numerous factors influence test drivers’ opinions while objective measures have the advantage of repeatability. However, objective methods of today are often only able to provide a rough grading of vehicles. The main objective with this thesis is to develop more sensitive objective methods for ride comfort evaluation. An effective test procedure to measure driver perception sensitivity to small differences in vehicle ride is suggested and utilized. The driver sensitivity is tested on dynamic behavior that is typically graded in vehicle development. Cab motions from a truck are first measured and then recreated in a simulator where a test driver is seated. The perception threshold for small changes in typical vehicle motion is established in this way for each test person. The perception sensitivity tests indicate that humans are quite sensitive to transients in vehicle motion. One problem with many common vehicle ride measures is that the impact of transient behavior is small due to the averaging used to condense the measurement data into scalar measures. A new evaluation method for ride comfort, with influences from the well known handling diagram, is suggested. This method has four main advantages: it is fairly simple to interpret, it shows the absolute vibration level, it considers transient events separately and it shows changes in vehicle character with increasing excitation. Promising results from both measurements and simulations are derived. New technology has made it possible to vary vehicle suspension parameters during vehicle ride. In order to prescribe different damping for different vehicle modes, modal motion estimates are needed. A system identification approach is suggested. It yields improved estimates of vehicle modal motion compared to previous work.QC 2010122

    Ride diagram : A tool for analysis of vehicle suspension settings

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    This paper proposes a new evaluation method for ride comfort, the ride diagram. The ride diagram is plotted from vehicle accelerations resulting from increased levels of excitation. The idea is to graphically visualize how the ride comfort changes with, for example, road unevenness or speed. The paper further focuses on investigating how fundamental suspension parameters affect the ride diagram shape. The ride diagram has the advantage over the conventional ride measures such as RMS and PSD spectrum that it considers transient events separately. Simulations with a quarter car model show that the ride diagram in several examples is able to separate transients due to nonlinear behaviour, e.g. limited suspension travel, from the stationary vibrations. The effects of choosing a softer suspension with a limited suspension travel are studied; the pros and cons are clearly visualized with the ride diagram. It thus looks promising to utilize the ride diagram for ride comfort evaluations.</p

    Truck Characterizing Through Ride Diagram

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    This paper presents the ride diagram, a new way of evaluating and presenting ride comfort Furthermore, a simplified methodology is suggested to test and correlate objective measures of vehicle ride with subjective driver impressions. The ride diagram is calculated from measured cab accelerations resulting from increased levels of excitation. The basic idea is to graphically visualize how ride comfort changes with excitation. Test drivers are then asked to pair the set of tested vehicles with corresponding curves in the ride diagram. This step assures that the selected measure captures how drivers apprehend changes in vehicle ride. The suggested methodology is illustrated on trucks with different cab suspension settings. For a given test track increased vehicle speed is used to increase the excitation level. The trucks are also placed in a road simulator to enable easy variation of both excitation type and level. Measurements shown in the ride diagram are compared to mean square and PSD analysis. Results show that the ride diagram has four main advantages; it is fairly simple to interpret, it shows the absolute vibration level, it considers transient events separately and it shows changes in vehicle character with increasing excitation.</p

    On Objective Measures for Ride Comfort Evaluation [Elektronisk resurs]

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    An essential tool in the truck development process is the ability to quantify and grade vehicle dynamic behavior. Today this is performed either through subjective or objective tests. Subjective tests have the disadvantage that numerous factors influence test drivers’ opinions while objective measures have the advantage of repeatability. However, objective methods of today are often only able to provide a rough grading of vehicles. The main objective with this thesis is to develop more sensitive objective methods for ride comfort evaluation. An effective test procedure to measure driver perception sensitivity to small differences in vehicle ride is suggested and utilized. The driver sensitivity is tested on dynamic behavior that is typically graded in vehicle development. Cab motions from a truck are first measured and then recreated in a simulator where a test driver is seated. The perception threshold for small changes in typical vehicle motion is established in this way for each test person. The perception sensitivity tests indicate that humans are quite sensitive to transients in vehicle motion. One problem with many common vehicle ride measures is that the impact of transient behavior is small due to the averaging used to condense the measurement data into scalar measures. A new evaluation method for ride comfort, with influences from the well known handling diagram, is suggested. This method has four main advantages: it is fairly simple to interpret, it shows the absolute vibration level, it considers transient events separately and it shows changes in vehicle character with increasing excitation. Promising results from both measurements and simulations are derived. New technology has made it possible to vary vehicle suspension parameters during vehicle ride. In order to prescribe different damping for different vehicle modes, modal motion estimates are needed. A system identification approach is suggested. It yields improved estimates of vehicle modal motion compared to previous work.</p
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