| 1. |
- Abdalla, Suliman, et al.
(författare)
-
Architecture and Circuit Design for Color X-Ray Pixal Array Detector Read-Out Electronics
- 2007
-
Ingår i: 24th Norchip Conference, 2006. - New York : IEEE conference proceedings. - 9781424407729 ; , s. 271-276
-
Konferensbidrag (refereegranskat)abstract
- This paper proposes an area- and power-efficient implementation of the read-out electronics for color X-ray pixel detectors for imaging. Introducing multiple levels of energy discrimination will increase the complexity of the read-out electronics in each pixel. The proposed architecture has full resolution for the intensity and reduced resolution for the energy spectrum (color), which leads to a good compromise of image quality and circuit complexity. We show that the increase in complexity, compared to single energy-range pixel, will lead to increase in circuit area of less than 20%.
|
|
| 2. |
- Ahmad, Naeem, et al.
(författare)
-
Model and placement optimization of a sky surveillance visual sensor network
- 2011
-
Ingår i: Proceedings - 2011 International Conference on Broadband and Wireless Computing, Communication and Applications, BWCCA 2011. - : IEEE Computer Society. - 9781457714559 ; , s. 357-362
-
Konferensbidrag (refereegranskat)abstract
- Visual Sensor Networks (VSNs) are networks which generate two dimensional data. The major difference between VSN and ordinary sensor network is the large amount of data. In VSN, a large number of camera nodes form a distributed system which can be deployed in many potential applications. In this paper we present a model of the physical parameters of a visual sensor network to track large birds, such as Golden Eagle, in the sky. The developed model is used to optimize the placement of the camera nodes in the VSN. A camera node is modeled as a function of its field of view, which is derived by the combination of the lens focal length and camera sensor. From the field of view and resolution of the sensor, a model for full coverage between two altitude limits has been developed. We show that the model can be used to minimize the number of sensor nodes for any given camera sensor, by exploring the focal lengths that both give full coverage and meet the minimum object size requirement. For the case of large bird surveillance we achieve 100% coverage for relevant altitudes using 20 camera nodes per km2 for the investigated camera sensors.
|
|
| 3. |
- Ahmad, Naeem
(författare)
-
Modelling and optimization of sky surveillance visual sensor network
- 2012
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A Visual Sensor Network (VSN) is a distributed system of a largenumber of camera sensor nodes. The main components of a camera sensornode are image sensor, embedded processor, wireless transceiver and energysupply. The major difference between a VSN and an ordinary sensor networkis that a VSN generates two dimensional data in the form of an image, whichcan be exploited in many useful applications. Some of the potentialapplication examples of VSNs include environment monitoring, surveillance,structural monitoring, traffic monitoring, and industrial automation.However, the VSNs also raise new challenges. They generate large amount ofdata which require higher processing powers, large bandwidth requirementsand more energy resources but the main constraint is that the VSN nodes arelimited in these resources.This research focuses on the development of a VSN model to track thelarge birds such as Golden Eagle in the sky. The model explores a number ofcamera sensors along with optics such as lens of suitable focal length whichensures a minimum required resolution of a bird, flying at the highestaltitude. The combination of a camera sensor and a lens formulate amonitoring node. The camera node model is used to optimize the placementof the nodes for full coverage of a given area above a required lower altitude.The model also presents the solution to minimize the cost (number of sensornodes) to fully cover a given area between the two required extremes, higherand lower altitudes, in terms of camera sensor, lens focal length, camera nodeplacement and actual number of nodes for sky surveillance.The area covered by a VSN can be increased by increasing the highermonitoring altitude and/or decreasing the lower monitoring altitude.However, it also increases the cost of the VSN. The desirable objective is toincrease the covered area but decrease the cost. This objective is achieved byusing optimization techniques to design a heterogeneous VSN. The core ideais to divide a given monitoring range of altitudes into a number of sub-rangesof altitudes. The sub-ranges of monitoring altitudes are covered by individualsub VSNs, the VSN1 covers the lower sub-range of altitudes, the VSN2 coversthe next higher sub-range of altitudes and so on, such that a minimum cost isused to monitor a given area.To verify the concepts, developed to design the VSN model, and theoptimization techniques to decrease the VSN cost, the measurements areperformed with actual cameras and optics. The laptop machines are used withthe camera nodes as data storage and analysis platforms. The area coverage ismeasured at the desired lower altitude limits of homogeneous as well asheterogeneous VSNs and verified for 100% coverage. Similarly, the minimumresolution is measured at the desired higher altitude limits of homogeneous aswell as heterogeneous VSNs to ensure that the models are able to track thebird at these highest altitudes.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Bader, Sebastian, et al.
(författare)
-
Remote image capturing with low-cost and low-power wireless camera nodes
- 2014
-
Ingår i: Proceedings of IEEE Sensors. - : IEEE Sensors Council. ; , s. 730-733
-
Konferensbidrag (refereegranskat)abstract
- Wireless visual sensor networks provide featurerich information about their surrounding and can thus be used as a universal measurement tool for a great number of applications. Existing solutions, however, have mainly been focused on high sample rate applications, such as video surveillance, object detection and tracking. In this paper, we present a wireless camera node architecture that targets low sample rate applications (e.g., manual inspections and meter reading). The major design considerations are a long system lifetime, a small size and a low production cost.We present the overall architecture with its individual design choices, and evaluate the architecture with respect to its application constraints. With a typical image acquisition cost of 1.5 J for medium quality images and a quiescent power demand of only 7 uW, the evaluation results demonstrate that long operation periods of the order of years can be achieved in low sample rate scenarios.
|
|
| 7. |
- Cao, Cao, et al.
(författare)
-
A Tool for Low-Power Synthesis of FSMs with Mixed Synchronous/Asynchronous State Memory
- 2004
-
Ingår i: 22ND NORCHIP CONFERENCE, PROCEEDINGS. - : IEEE. - 0780385101 ; , s. 199-202
-
Konferensbidrag (refereegranskat)abstract
- An efficient way to obtain Finite-State Machines (FSMs) with low power consumption is to,partition the machine into two or more sub-FSMs and use dynamic power management, where all sub-FSMs not active are shut down, to reduce dynamic power dissipation. In this paper we focus on FSM partitioning algorithms and RT-level power estimation functions that are the key issues in the design of a CAD tool for synthesis of low-power partitioned FSMS. We target an implementation architecture that is based on both synchronous and asynchronous state memory elements that enables larger power reductions than fully synchronous architectures do. Power reductions of up to 77% have been achieved at a cost of an increase in area of 18%.
|
|
| 8. |
- Cao, Cao, et al.
(författare)
-
Synthesis tool for low-power finite-state machines with mixed synchronous/asynchronous state memory
- 2006
-
Ingår i: IEE Proceedings - Computers and digital Techniques. - : Institution of Engineering and Technology (IET). - 1350-2387 .- 1359-7027. ; 153:4, s. 243-248
-
Tidskriftsartikel (refereegranskat)abstract
- An efficient way to obtain finite-state machines (FSMs) with low-power consumption is to partition the machine into two or more sub-FSMs and then use dynamic power management where all sub-FSMs not active are shut down, with the effect of reducing dynamic power dissipation. Thus, FSM partitioning algorithms and register-transfer-level power estimation functions are the main focus of the paper as these are key issues in the design of a computer-aided design tool for synthesis of low-power partitioned FSMs. An implementation architecture is targeted, which is based on both synchronous and asynchronous state memory elements that enable larger power reductions than fully synchronous architectures do. Power reductions of up to 77 have been achieved at a cost of an 18 increase in area.
|
|
| 9. |
- Cheng, Peng
(författare)
-
Applications of embedded sensors in loader crane positioning and rotor RPM measurement
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, two novel applications involving embedded sensors arestudied, one dealing with loader crane positioning and the other involving rotorRevolutions Per Minute (RPM) measurement. The thesis presents a generalintroduction to the embedded sensor, its architecture and its use in mechanicalindustry, and provides the reader with an overview of conventional sensortechnologies within the fields of angle sensors and angular speed sensors, coveringtheir working principles, features, advantages and disadvantages and typicalapplications. The particular problems associated with the use of conventionalsensors in both loader crane positioning and rotor RPM measurement aredescribed and these problems provided the motivation for the designs of theembedded sensor systems developed in this thesis.In the case of the loader crane positioning, the origins of the project and thespecial requirements of the application are described in detail. In addition, apreliminary study is conducted in relation to the idea of a contactless joint angularsensor using MEMS inertial sensors in which four different methods, namely, theCommon-Mode-Rejection with Gyro Integration (CMRGI), Common-Mode-Rejection (CMR), Common-Mode-Rejection with Gyro Differentiation (CMRGD)and Distributed Common-Mode-Rejection (DCMR), are conceived, modeled andtested on a custom-designed prototype experimental setup. The results gatheredfrom these four methods are compared and analyzed in order to identify thedifferences in their performances. The methods, which proved to be suitable, arethen further tested using the prototype sensor setup on a loader crane and theperformance results are analyzed in order to make a decision in relation to the twomost suitable methods for the application of the loader crane positioning. Theresults suggested that the two most suitable were the CMRGD and the DCMR. Thepractical design issues relating to this sensor system are highlighted andsuggestions are made in the study. Additionally, possible future work for thisproject is also covered.In the first case for the rotor RPM measurement, the thesis presents themodeling and simulation of the stator-free RPM sensor idea using the Monte Carlomethod, which demonstrated the special features and performance of this sensor.The design aspects of the prototype sensor are described in detail and theprototype is tested on an experimental setup. The conclusions for the stator-freeRPM sensor are then made from the analysis of the experimental results and futurework in relation to this sensor is also proposed.In the second case of the rotor RPM measurement, the thesis presentsanother idea involving the laser mouse RPM sensor and the main focus of thestudy is on the performance characterization of the laser mouse sensor and theverification of the RPM sensor idea. Experiments are conducted using the test setup and results are gathered and analyzed and conclusions are drawn.Possibilities in relation to future work for this laser mouse RPM sensor are alsoprovided.The summary and the conclusion form the final chapter of the thesis andseveral important aspects of the designs relating to both the loader cranepositioning project and the rotor RPM measurement project are discussed.
|
|
| 10. |
- Imran, Muhammad, et al.
(författare)
-
Energy Efficient SRAM FPGA based Wireless Vision Sensor Node: SENTIOF‐CAM
- 2014
-
Ingår i: IEEE transactions on circuits and systems for video technology (Print). - 1051-8215 .- 1558-2205. ; 24:12, s. 2132-2143
-
Tidskriftsartikel (refereegranskat)abstract
- Many Wireless Vision Sensor Networks (WVSNs) applications are characterized to have a low duty cycling. An individual wireless Vision Senor Node (VSN) in WVSN is required to operate with limited resources i.e., processing, memory and wireless bandwidth on available limited energy. For such resource constrained VSN, this paper presents a low complexity, energy efficient and programmable VSN architecture based on a design matrix which includes partitioning of processing load between the node and a server, a low complexity background subtraction, bi-level video coding and duty cycling. The tasks partitioning and proposed background subtraction reduces the processing energy and design complexity for hardware implemented VSN. The bi-level video coding reduces the communication energy whereas the duty cycling conserves energy for lifetime maximization. The proposed VSN, referred to as SENTIOF-CAM, has been implemented on a customized single board, which includes SRAM FPGA, microcontroller, radio transceiver and a FLASH memory. The energy values are measured for different states and results are compared with existing solutions. The comparison shows that the proposed solution can offer up to 69 times energy reduction. The lifetime based on measured energy values shows that for a sample period of 5 minutes, a 3.2 years lifetime can be achieved with a battery of 37.44 kJ energy. In addition to this, the proposed solution offers generic architecture with smaller design complexity on a hardware reconfigurable platform and offers easy adaptation for a number of applications.
|
|
