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Conventional systems for motion context detection rely on batteries to provide the energy required for sampling a motion sensor. Batteries, however, have limited capacity and, once depleted, have to be replaced or recharged. Kinet...
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Conventional systems for motion context detection rely on batteries to provide the energy required for sampling a motion sensor. Batteries, however, have limited capacity and, once depleted, have to be replaced or recharged. Kinetic Energy Harvesting (KEH) allows to convert ambient motion and vibration into usable electricity and can enable batteryless, maintenance free operation of motion sensors. The signal from a KEH transducer correlates with the underlying motion and may thus directly be used for context detection, saving space, cost and energy by omitting the accelerometer. Previous work uses the open circuit or the capacitor voltage for sensing without using the harvested energy to power a load. In this paper, we propose to use other sensing points in the KEH circuit that offer information-rich sensing signals while the energy from the harvester is used to power a load. We systematically analyze multiple sensing signals available in different KEH architectures and compare their performance in a transport mode detection case study. To this end, we develop four hardware prototypes, conduct an extensive measurement campaign and use the data to train and evaluate different classifiers. We show that sensing the harvesting current signal from a transducer can be energy positive, delivering up to ten times as much power as it consumes for signal acquisition, while offering comparable detection accuracy to the accelerometer signal for most of the considered transport modes.
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摘要 :
Conventional systems for motion context detection rely on batteries to provide the energy required for sampling a motion sensor. Batteries, however, have limited capacity and, once depleted, have to be replaced or recharged. Kinet...
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Conventional systems for motion context detection rely on batteries to provide the energy required for sampling a motion sensor. Batteries, however, have limited capacity and, once depleted, have to be replaced or recharged. Kinetic Energy Harvesting (KEH) allows to convert ambient motion and vibration into usable electricity and can enable batteryless, maintenance free operation of motion sensors. The signal from a KEH transducer correlates with the underlying motion and may thus directly be used for context detection, saving space, cost and energy by omitting the accelerometer. Previous work uses the open circuit or the capacitor voltage for sensing without using the harvested energy to power a load. In this paper, we propose to use other sensing points in the KEH circuit that offer information-rich sensing signals while the energy from the harvester is used to power a load. We systematically analyze multiple sensing signals available in different KEH architectures and compare their performance in a transport mode detection case study. To this end, we develop four hardware prototypes, conduct an extensive measurement campaign and use the data to train and evaluate different classifiers. We show that sensing the harvesting current signal from a transducer can be energy positive, delivering up to ten times as much power as it consumes for signal acquisition, while offering comparable detection accuracy to the accelerometer signal for most of the considered transport modes.
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The cognitive radio technology promises to become the solution to the spectrum scarcity problem, allowing secondary (unlicensed) users to opportunistically access vacant frequency bands licensed to primary users. Cooperative spect...
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The cognitive radio technology promises to become the solution to the spectrum scarcity problem, allowing secondary (unlicensed) users to opportunistically access vacant frequency bands licensed to primary users. Cooperative spectrum sensing is the technique used to discover the unoccupied frequency bands, in the presence of strong fading and shadowing effects. In addition, cooperative spectrum sensing allows to exploit positioning information as well as location awareness. The cooperative sensors are usually assumed independent each other, in order to simplify the analysis. Conversely, here we consider the case of correlated observations and propose a new double threshold test, in order to improve the detection performance, while reducing the time requested to detect a primary user. Our test combines two different fusion rules at once (i.e. the OR and the Majority voting rules), recovering all those unlucky detection cases that are not sensed due to strong shadowing. Finally, our simulation results show the effectiveness of the proposed method for application to cooperative sensing for positioning in the presence of correlated observations.
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This paper presents an experimental investigation of the accuracy and repeatability dependency on speed for MELFA robots. The study was conducted using a MELFA RV-2F robot arm equipped with a high-precision displacement sensor to ...
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This paper presents an experimental investigation of the accuracy and repeatability dependency on speed for MELFA robots. The study was conducted using a MELFA RV-2F robot arm equipped with a high-precision displacement sensor to measure the end-effector position. The robot arm was programmed to perform a series of point-to-point movements at different speeds, and the position error and repeatability were measured and analyzed. The results indicate that the accuracy and repeatability of the MELFA robot are strongly dependent on the speed of the robot arm. At low speeds, the robot arm exhibits high accuracy and repeatability, while at high speeds, the accuracy and repeatability decrease significantly. These findings have important implications for the design and operation of MELFA robots and can be used to optimize their performance in various industrial applications.
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Energy efficient bi-stable latching valves are well suited, for instance, for applications in which only a limited energy supply is available. Especially for those applications, the conventional control by using constant voltage p...
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Energy efficient bi-stable latching valves are well suited, for instance, for applications in which only a limited energy supply is available. Especially for those applications, the conventional control by using constant voltage pulses offers potential for further energy savings by applying only the required switching energy to the coil. For this purpose, an end stop detection by using position estimation is proposed and implemented onto cost-efficient electronics for commercial use. The approach is investigated and its functionality is successfully demonstrated in a realistic environment by using a fluid-operated valve at different ambient temperatures and supply pressures.
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The present study designed a synergistic integration method of a detection-based network and embedded CO_2 sensors to reach a high level of occupancy estimation accuracy for other sustainable building applications. The method was ...
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The present study designed a synergistic integration method of a detection-based network and embedded CO_2 sensors to reach a high level of occupancy estimation accuracy for other sustainable building applications. The method was deployed in an office building to explore the potential of the approach through two types of field tests: 1) Baseline test with a detection mode-only for occupancy, and 2) Case study with CO_2 measurement-integrated smart-sensing occupancy estimation. The mutual supplementary use of CO_2 measurements could enhance the estimation accuracy up to 98.3%. This occupancy estimation advancement will enhance the accuracy/efficiency of occupancy-based demand controls in real applications, leading to substantial reduction of building-operational energy.
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During September 15 to October 5, 1997, an intensive experiment to measure atmospheric water vapor was conducted at the Department of Energy's Atmospheric Radiation Measurement Program's Cloud and Radiation Testbed (CART) site in ...
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During September 15 to October 5, 1997, an intensive experiment to measure atmospheric water vapor was conducted at the Department of Energy's Atmospheric Radiation Measurement Program's Cloud and Radiation Testbed (CART) site in north central Oklahoma. This experiment was called the 1997 Water Vapor Intensive Operating Period (WVIOP'97). Among the goals of WVIOP'97 was the comparison of different methods of measuring precipitable water vapor (PWV). This paper focuses on the inter-comparison of PWV measurements by ground-based microwave radiometers, Global Positioning System-PWV instruments (GPS-PWV), and by radiosondes. For this experiment 3-hourly radiosondes for in situ measurements were deployed. Microwave radiometric measurements of water vapor in the zenith direction were made by two independent radiometers that produce PWV and cloud liquid path from brightness temperature T/sub b/ measurements. These radiometers were operated by the Environmental Technology Laboratory and operate at the frequency pairs of (20.6, 31.65 GHz) and (23.87, 31.65 GHz). The calibration of the instruments was achieved by the so-called "tip cal" method and their data, in terms of derived PWV are compared. Two independent GPS-PWV instruments were also operated 9 km apart and, in addition, two different processing algorithms were applied to the data from each of these instruments.
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Personal mobile devices are widespread and carried by their users most of the time over the day. Thanks to the integrated sensors they can report about visited places, movement types and speed of the users. However, efficient stop...
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Personal mobile devices are widespread and carried by their users most of the time over the day. Thanks to the integrated sensors they can report about visited places, movement types and speed of the users. However, efficient stopping event detection on public transport vehicles is still a challenge. These events, associated with the coordinates of real stations, can be useful to update public transit timetables according to real-time traffic. In field tests we evaluated the most commonly available suitable sensors' precision and efficiency and developed our Stopping Event Detection Algorithm (SEDA), which utilizes only the accelerometer to find potential stopping times and the Wi-Fi sensor to validate or discard them by a novel localization method. Wi-Fi is used only 6.66% of the time of actual traveling on public vehicles. Our algorithm is shown to recognize properly 82.9–89.47% of public traffic stations while consuming daily only 13% the capacity of an average smartphone's battery.
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摘要 :
Personal mobile devices are widespread and carried by their users most of the time over the day. Thanks to the integrated sensors they can report about visited places, movement types and speed of the users. However, efficient stop...
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Personal mobile devices are widespread and carried by their users most of the time over the day. Thanks to the integrated sensors they can report about visited places, movement types and speed of the users. However, efficient stopping event detection on public transport vehicles is still a challenge. These events, associated with the coordinates of real stations, can be useful to update public transit timetables according to real-time traffic. In field tests we evaluated the most commonly available suitable sensors' precision and efficiency and developed our Stopping Event Detection Algorithm (SEDA), which utilizes only the accelerometer to find potential stopping times and the Wi-Fi sensor to validate or discard them by a novel localization method. Wi-Fi is used only 6.66% of the time of actual traveling on public vehicles. Our algorithm is shown to recognize properly 82.9–89.47% of public traffic stations while consuming daily only 13% the capacity of an average smartphone's battery.
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Airborne ground penetrating radar (GPR) is a suitable tool to perform cost-effective surveys of the underground of a large possibly non-accessible areas. And It is concluded that airborne GPR will receive more attention in the fut...
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Airborne ground penetrating radar (GPR) is a suitable tool to perform cost-effective surveys of the underground of a large possibly non-accessible areas. And It is concluded that airborne GPR will receive more attention in the future. So we have developed a L-band Full-polarimetric Step-Frequency GPR acquisition system, which consists of a GPS receiver, the Vivaldi antenna, a signal amplifier and a vector network analyzer (VNA) under the control of a PC unit. The main objective of our work is to conduct some experiments to test the feasibility of this airborne testing system.
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