A control system to regulate the temperature of the micro hotplate in a MEMS gas sensor is presented. The controlelement, called micro hotplate, is comprised of a micro heater and a temperature sensor, both made with ...
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A control system to regulate the temperature of the micro hotplate in a MEMS gas sensor is presented. The controlelement, called micro hotplate, is comprised of a micro heater and a temperature sensor, both made with polysilicon, located near each other. This material has a Temperature Coefficient of Resistance (TCR) that is the basis for the design of the temperature controller of the gas sensor system. A high temperature between 250 and 400°C is needed to produce a chemical reaction between the gas and the sensing film, hence a reliable temperature control for the micro hotplate is desired. Thermal insulation of the circuitry from the heating element, having a monolithic sensor system, and low power consumption, are the main specifications for the system. This is obtained by means of a micro pit realized with MEMS micromachining processes. The analysis of the circuit proposed to fulfill these characteristics is presented, for its future integration with a standard CMOS technology. A trade off is established between the sensor structure parameters and the circuit design.
The convergent feature of traffic in wireless body area networks (WBANs) makes congestion in certain areas which are the place of events and/or the location of sensor nodes near a sink. Congestion brings packet loss, ...
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In this paper, the speed observer design problem for induction motors is approached by means of an estimation technique which exploits some properties of the error dynamics that make feasible to express this system as...
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In this paper, the speed observer design problem for induction motors is approached by means of an estimation technique which exploits some properties of the error dynamics that make feasible to express this system as a feedback interconnection, subject to a disturbance signal, of two subsystems that can be rendered passive via a proper choice of the output injection terms. Then, a semiglobal convergent low order observer, which simultaneously estimates rotor fluxes and motor speed in presence of unknown constant load torque, is proposed. Passive speed observer performance is experimentally evaluated and compared with results obtained under the same conditions for an observer based on a model reference adaptive system technique.
Preliminary results are presented of a comparison made between a model checking tool developed by our research group and Spin, a public domain model checking package. The theoretical fundaments of both tools are expli...
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Preliminary results are presented of a comparison made between a model checking tool developed by our research group and Spin, a public domain model checking package. The theoretical fundaments of both tools are explicit model checking based on language emptiness. Using a simple example consisting of a set of logic controllers for driving the operation of pressurized tanks, we compare the computing performance of each stage in the model checking procedure for safety and liveness properties given as linear temporal logic (LTL) formulas. The controller ladder logic is modeled as a generalized Buchi automaton. Numerical results show a better performance of our tool for domains of up to 10 3 states
This paper introduces the digital photo frame project which based on the FrameBuffer[3] and Linux operating system. The digital photo frame is designed for digital format photos instead of paper photos through liquid ...
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ISBN:
(纸本)9781849195379
This paper introduces the digital photo frame project which based on the FrameBuffer[3] and Linux operating system. The digital photo frame is designed for digital format photos instead of paper photos through liquid crystal display screen. At the same time, special effects can be used on pictures while playing music. And the project focus on more novel picture shows effects to make it stand out. Finally, on the mini2440 development board, the whole design is realized completely.
Traditional warning signs use human retrograde placement;there are problems such as short warning distances, imprecise placement positions, and difficult positioning of accident points. According to statistics, the us...
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Intelligent Autonomous Systems (IAS) are highly cognitive, reflective, multitask-able, and effective in knowledge discovery. Examples of IAS include software systems that are capable of automatic reconfiguration, auto...
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ISBN:
(纸本)9781538695555
Intelligent Autonomous Systems (IAS) are highly cognitive, reflective, multitask-able, and effective in knowledge discovery. Examples of IAS include software systems that are capable of automatic reconfiguration, autonomous vehicles, network of sensors with reconfigurable sensory platforms, and an unmanned aerial vehicle (UAV) respecting privacy by deciding to turn off its camera when pointing inside a private residence. Research is needed to build systems that can monitor their environment and interactions, learn their capabilities and limitations, and adapt to meet the mission objectives with limited or no human intervention. The systems should be fail-safe and should allow for graceful degradations while continuing to meet the mission objectives. In this paper, we provide an overview of our proposed new methodologies and workflows, and survey the existing approaches and new ones that can advance the science of autonomy in smart systems through enhancements in real-time control, auto-reconfigurability, monitoring, adaptability, and trust. This paper also provides the theoretical framework behind IAS.
Applying a π/2 frequency shift to the original twochannel quadrature mirror filter bank (QMFB) yields an equivalent system with two complex half-band filters. Since their coefficients are complex conjugate to each ot...
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The purpose of this research is devoted to establishing a running generation technique for bipedal robots. The motion generator is based on the Bipedal Spring-Loaded Inverted Pendulum Model (Bi-SLIPM) and is designed ...
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The transport mechanisms in both silicon porous layers (PSL) and ZnO/PSL/c-Si heterostructures were identified by Current-Voltage (I-V) measurements. The PSL were made by anodic etching of p-type (100) Silicon (Si) wa...
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The transport mechanisms in both silicon porous layers (PSL) and ZnO/PSL/c-Si heterostructures were identified by Current-Voltage (I-V) measurements. The PSL were made by anodic etching of p-type (100) Silicon (Si) wafers with resistivity of 1-5 ¿-cm. The heterostructures were manufactured by depositing a zinc oxide (ZnO) film by DC-sputtering on the previously obtained PSL. The measured electrical resistivity of the ZnO films and the PSL were of 5.3 × 10 5 and 5.7 × 10 7 ¿-cm, respectively. The current flow in the PSL is limited by the space-charge regions (SCL), due to the charge trapped in the distinct energy localized states. For the heterostructures similar results were found, where the dominant transport mechanisms are associated to the physical characteristics of the PSL and the ZnO films. Accordingly a bandgap diagram for ZnO/PSL heterostructure is proposed, where the participation of the variety of the defect levels are considered.
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