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- Consequences (4)
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Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (11)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (11)
- 2 Prozess- und Anlagensicherheit (4)
- 2.1 Sicherheit von Energieträgern (4)
- 2.2 Prozesssimulation (2)
- 3 Gefahrgutumschließungen; Energiespeicher (2)
- 3.0 Abteilungsleitung und andere (2)
- 7 Bauwerkssicherheit (2)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (2)
- 1 Analytische Chemie; Referenzmaterialien (1)
In mobile robot applications, some sensors such as open-path gas detectors or laser rangefinders need to be aimed at specific targets in order to get the desired measurements. To do this in a fast and elegant manner, we present a spherical parallel manipulator with three degrees of freedom. Compared to typical serial manipulators, it offers superior dynamics and structural stiffness, which are important parameters for this type of task. We present the mechanical design and derive kinematic equations both to compute set-points for the desired orientation and to estimate the current state of the system. A PID controller is used to generate control signals.
A current-independent torque equation for the permanent-magnet synchronous motor (PMSM) aiming at direct-drive servo applications is derived from a first principles model. Instead of measuring currents, all required control parameters are derived from optical incremental encoder measurements. The results are verified on a real system in test series showing the effect of static friction and proving the obtained torque model.
In robotic applications, it is often necessary to orient a sensor quickly. Spherical parallel manipulators (SPM) are well suited for this purpose since they offer superior dynamics and structural stiffness as compared to serial manipulators. To control them, however, the kinematic equations have to be known. In this paper, a SPM with three degrees of freedom and the kinematic equations describing its mechanical properties are presented.
A permanent-magnet synchronous motor (PMSM) servo drive for lightweight robotic platforms that have a high torque demand at low rotational speeds has been developed. First, a current-independent torque controller is derived and cascaded with a speed and position controller, while merely an encoder is used as a sensor device in combination with a speed estimator. Finally, the speed estimator output is compared to gyroscope measurements and the overall functioning is verified on a real system.
For several applications involving multirotor aircraft, it is crucial to know both the direction and speed of the ambient wind. In this paper, an approach to wind vector estimation based on an equilibrium of the principal forces acting on the aircraft is shown. As the thrust force generated by the rotors depends on their rotational speed, a sensor to measure this quantity is required. Two concepts for such a sensor are presented: One is based on tapping the signal carrying the speed setpoint for the motor controllers, the other one uses phototransistors placed underneath the rotor blades. While some complications were encountered with the first approach, the second yields accurate measurement data. This is shown by an experiment comparing the proposed speed sensor to a commercial non-contact tachometer.
This paper describes a wireless mobile prototype able to perform optical measurements by means of a miniatur-ized spectrometer for low light analysis, e.g. fluorescent sensors. Evaluations, calculations, calibration management and result display are performed by a computer or a standard tablet. The device was designed primarily to detect traces of oil in drinking or ground water and for the analyses of crude oils. However, it can also address a wide range of fluorescent sensors. The fast and user-friendly inspection of water quality or oil properties, as well as the adaptability and mobility, make the device attractive for a variety of users. Further application areas could be easily imple-mented by adapting the optics and the software (database, data processing and calibration plots, etc.)
15 identical off-the-shelf propane cylinders (m = 11 kg liquid propane) were underfired. The infrared Radiation of the Explosion, that occurred in the aftermath of the vessel failure, was recorded using four bolometers. These measurements are compared with an estimation of the Maximum intensity gained by an Analysis of the Video data, an Extended Version of the Stefan-Boltzmann law and a BLEVE model.
In continuation of a preceding test series involving sole LPG vehicle tanks, three passenger cars equipped with identical toroidal steel LPG tanks were set on fire. The tanks were installed in the space normally reserved for the spare tyre, in the car boot. No safety device was installed on the tank, in order to force critical failure of the cylinder. Two of the cars were equipped with a tank filled with liquefied propane to a level of 20 % (5.3 kg), the third one was filled completely (25.5 kg). The partially filled tanks failed critically within a time period of more than 20 min after the initiation of the fire. The fully-filled tank did not rupture; the propane was released continuously through a small leak that appeared during the fire. Comprehensive equipment was used to procure measurement data, enabling an analysis of potential consequences and hazards to humans and infrastructure within the vehicle surroundings. The inner status of the tank (pressure, temperature of the liquid phase and the steel casing), the development of the fire (temperature inside and around the vehicle) and the pressure induced in the near-field in case of tank rupture were recorded. The results were analysed in detail and compared against the data gained in tests involving sole, but identical LPG tanks.