The importance of real-time communication at the device level in a factory automation setup is a widely researched area. This research is an effort to experimentally verify if Ethernet can be used as a real-time communication standard in a factory automation setup, by observing the effects of packet delays, packet loss, and network congestion on the performance of a networked control system (NCS). The NCS experimental setup used in this research involves real-time feedback control of multiple plants like DC motors and a magnetic-levitation system connected to one or more controllers. A multi-client-multi-server architecture on a local area network (LAN) was developed using user datagram protocol (UDP) as the communication protocol. Key observations are as follows. (1) The multi-client-single-server system showed the highest packet delays compared to single-client-single-server architecture. (2) In the singleclient- single-server system, as the Ethernet link utilization increased beyond 82 percent, the average packet delays and steady-state error of the DC motor speed-control system increased by 2231 percent and 304 percent, respectively. (3) Even under high link utilization, adding an additional server to the NCS reduced average packet delays considerably. (4) With large packet sizes, higher packet rates were automatically throttled by Ethernet’s flow control mechanism affecting the real-time communication negatively. (5) In the multiclient- multi-server architecture, average packet delays at higher packet rates, and at higher packet lengths were found to be 40 percent lesser than the those of the single-clientsingle- server system and 87.5 percent lesser than those of the multi-client-single-server system.

In recent years, the requirement for embedded controllers has been steadily on the increase due to the development of computers, communication and consumptive products. In order to overcome the pressure of short life-time and rapid changing rate of products, however, related industries have been engaged in improving their design to shorten the time to market and to lower the cost. Therefore, a new concept, rapid controller prototyping, has been proposed to solve the problem with the development of controllers. However, most of the proposals are expensive and restricted in the choice of software and hardware, and aren¡¦t adequate for research. To solve the problems above, this paper has chosen MATLAB/Simulink, Real-Time Workshop, a software widely used by the academic community, as tools to study rapid controller prototyping. Here, we also focus on the establishment of the developing platform. Then we design, simulate and test the controller on the platform established. Finally, we apply the controller to the physical plant. By doing so, this paper expects to solve current problems in the development of controllers.

Nowadays almost all products used in our daily life are made in pursuit of streamline and good look, including mobiles, motorcycles, aerospace and 3C industry; therefore, how to shorten process time and enhance the smoothness of the product¡¦s surface has become one of the important issues. However, the process method of traditional CNC machines only can support line and circular interpolations but cannot accept motion along curve and circular paths. Therefore, the traditional CNC machines have to rely on CAM, a method to generate the NC code called G-code and M-code by approximating many tiny linear or circular segments, to plan the cutter paths. But this approximating method requires higher transmission speed; it also occupies huge memory capacity and makes the velocity of machine tool discontinuous, in order to difficultly meet the requirement of high speed and better precision. In order to solve the above problems, this thesis adopts the NC code created by CAD/CAM¡¦s NURBS curve which called NURBS-code, making CNC machines have the function of processing NURBS curve interpolations to improve the defect of the traditional processing and thus reach the goal of high speed and better precision. Furthermore, due to NURBS interpolators are always implemented by the controller. This always makes CNC machine become very expensive; meanwhile, adjusting parameters is very troublesome. Therefore this thesis also provides the intergrated method of NURBS and DDA real-time interpolator to make the application in the easy way without the consideration of controller design for AC driver.

The digital image processing has been developed for a long time. The image detection and tracking are involved to a variety of digital techniques. In this research we introduce the digital image processing techniques, base on a boosted cascade of simple features to develop a face detection and tracking system. Due to a large amount of computation in face detection under the complex environment will affect the detection rate and velocity efficiency. Therefore, we use the extended feature and set of 45ﾟ rotated feature with fast feature computation which called the integral image, combine with the deformable templates. We can compute a part of the image block to reduce the computation and improve the system. In the PAN-TILT unit, we use fuzzy logic. The results of experiment show that system is robust and fast.

In this work we propose a methodology for providing real-time capabilities to component-based, on-the-fly reconfigurable, distributed systems. In such systems, software components migrate across computational resources at run-time to allow applications to adapt to changes in user requirements or to external events. We describe how we achieve run-time reconfiguration in distributed Java applications by appropriately migrating servers. Guaranteed-rate schedulers at the servers provide the necessary temporal protection and so simplify remote method invocation management. We describe how we manage overhead and resource utilization by controlling the parameters of the server schedulers. According to our measurements, this methodology provides real-time capability to component-based reconfigurable distributed systems in an effcient and effective way. In addition, we propose a new resource discovery protocol, REALTOR, which is based on a combination of pull-based and push-based resource information dissemination. REALTOR has been designed for real-time component-based distributed applications in very dynamic or adverse environments. REALTOR supports survivability and information assurance by allowing the migration of components to safe locations under emergencies suchas externalattack, malfunction, or lackofresources. Simulation studies show that under normal and heavy load conditions REALTOR remains very effective in finding available resources, and does so with a reasonably low communication overhead.REALTOR 1)effectively locates resources under highly dynamic conditions, 2) has an overhead that is system-size independent, and 3) works well in highlyadverse environments.We evaluate the effectiveness of a REALTOR implementation as part of Agile Objects, an infrastructure for real-time capable, highly mobile Java components.

In the first phase of this study, the diversity of methanogenic bacteria in avian ceca was found to be minimal. Based on 16S rDNA clone libraries, a common phylotype, designated CH101, ranged between 92.86 to 100 % of the total clones whereas less than 1% of the other phylotypes were found. On the basis of the sequence identity, all of the sequences, except sequence CH1270, are related from 98.97 to 99.45% to 16S rDNA Methanobrevibacter woesei GS. Sequence CH1270 is 97.62% homologous to the sequence identified to uncultured archaeon clone ConP1-11F. Clearly, the predominant methanogen found to reside in the chicken ceca was M. woesei. By using a MPN enumeration method, methanogen counts were found to be in the range of 6.38 to 8.23 log10 organisms per gram wet weight. The 16S rDNA copy number per gram wet weight in the samples was between log10 5.50 and 7.19. The second phase of the study was conducted to observe the effects of selected nitrocompounds and two different feedstuffs on in vitro methane production in chicken cecal contents and rumen fluid. Initially, one of the three nitrocompounds was added to incubations containing cecal contents from laying hens supplemented with either alfalfa or layer feed. Both feed materials influenced volatile fatty acids (VFA) production and also fostered methane production in the incubations although methane was lower (P < 0.05) in incubations with added nitrocompound, particularly nitroethane. Secondly, nitroethane was examined in incubations of bovine or ovine rumen fluid or cecal contents containing either alfalfa or layer feed. Unlike cecal contents, layer feed significantly (P < 0.05) supported in vitro methane production in incubations of both rumen fluids. The results show that nitroethane impedes methane production, especially in incubations of chicken cecal contents. The final phase of this study was carried out to determine the methanogenic establishment in the chicken ceca by the cultural method with the quantitative PCR. The results suggested that methanogens colonized in chicken ceca at a few days after birth. Litter and house flies could be potential sources for methanogenic colonization in broiler chicks.

A control system in which sensors, actuators, and controllers are interconnected over a communication network is called a networked control system (NCS). Enhanced computational capabilities and bandwidths in the networking technology enabled researchers to develop NCSs to implement distributed control schemes. This dissertation presents a framework for the modeling, design, stability analysis, control, and bandwidth allocation of real-time control over networks. This framework covers key research issues regarding control over networks and can be the guidelines of NCS design. A single actuator ball magnetic-levitation (maglev) system is implemented as a test bed for the real-time control over networks to illustrate and verify the theoretical results of this dissertation. Experimentally verifying the feasibility of Internet-based real-time control is another main objective of this dissertation. First, this dissertation proposes a novel NCS model in which the effects of the networkinduced time delay, data-packet loss, and out-of-order data transmission are all considered. Second, two simple algorithms based on model-estimator and predictor- and timeout-scheme are proposed to compensate for the network-induced time delay and packet loss simultaneously. These algorithms are verified experimentally by the ball maglev test bed. System stability analyses of original and compensated systems are presented. Then, a novel co-design consideration related to real-time control and network communication is also proposed. The working range of the sampling frequency is determined by the analysis of the system stability and network parameters such as time delay, data rate, and data-packet size. The NCS design chart developed in this dissertation can be a useful guideline for choosing the network and control parameters in the design of an NCS. Using a real-time operating system for real-time control over networks is also proposed as one of the main contributions of this dissertation. After a real-time NCS is successfully implemented, advanced control theories such as robust control, optimal control, and adaptive control are applied and formulated to improve the quality of control (QoC) of NCSs. Finally, an optimal dynamic bandwidth management method is proposed to solve the optimal network scheduling and bandwidth allocation problem when NCSs are connected to the same network and are sharing the network resource.

This work is devoted to formulation and development of a laser spectroscopic technique for rapid detection of biohazards, such as Bacillus anthracis spores. Coherent anti-Stokes Raman scattering (CARS) is used as an underlying process for active retrieval of species-specific characteristics of an analyte. Vibrational modes of constituent molecules are Raman-excited by a pair of ultrashort, femtosecond laser pulses, and then probed through inelastic scattering of a third, time-delayed laser field. We first employ the already known time-resolved CARS technique. We apply it to the spectroscopy of easy-to-handle methanol-water mixtures, and then continue building our expertise on solutions of dipicolinic acid (DPA) and its salts, which happen to be marker molecules for bacterial spores. Various acquisition schemes are evaluated, and the preference is given to multi-channel frequency-resolved detection, when the whole CARS spectrum is recorded as a function of the probe pulse delay. We demonstrate a simple detection algorithm that manages to differentiate DPA solution from common interferents. We investigate experimentally the advantages and disadvantages of near-resonant probing of the excited molecular coherence, and finally observe the indicative backscattered CARS signal from DPA and NaDPA powders. The possibility of selective Raman excitation via pulse shaping of the preparation pulses is also demonstrated. The analysis of time-resolved CARS experiments on powders and B. subtilis spores, a harmless surrogate for B. anthracis, facilitates the formulation of a new approach, where we take full advantage of the multi-channel frequency-resolved acquisition and spectrally discriminate the Raman-resonant CARS signal from the background due to other instantaneous four-wave mixing (FWM) processes. Using narrowband probing, we decrease the magnitude of the nonresonant FWM, which is further suppressed by the timing of the laser pulses. The devised technique, referred to as hybrid CARS, leads to a single-shot detection of as few as 104 bacterial spores, bringing CARS spectroscopy to the forefront of potential candidates for real-time biohazard detection. It also gives promise to many other applications of CARS, hindered so far by the presence of the overwhelming nonresonant FWM background, mentioned above.

This thesis presents a robust real-time active tracking system with a pan-tilt camera. The proposed visual servo framework is able to track a deformed object and maintain the target always inside the field of view. For the image processing, an efficient template matching and searching method using the mean-shift theory is developed. The robustness is achieved by appending the ratio histogram, a kernel function, and the template update to the framework when the target is deformed. Then the pan-tilt unit turns towards the target and keeps the target inside the field of view of the camera by feeding back the position information to a Kalman filter. Experimental results show that the presented scheme works successfully when the target is vague or concealed or deformed. The visual tracking task can also be accomplished even when a similar object crosses over the target. In addition, the refreshing rate can be up to 60 frames per second.

Scratchpad memory (SPM) is popular for real-time embedded systems. Whereas caches use a memory management unit (MMU) to control which data accesses go to the fast, on-chip SRAM, SPM directly maps certain addresses to the SRAM. One advantage of SPM is that it avoids the cache¡¦s costly MMU. Another advantage is that the SPM is 100% statically predictable, whereas the variables stored in the cache depend upon the dynamic execution history. This predictability is beneficial for real-time systems which must schedule tasks to finish by fixed deadlines. To set these deadlines, system designers must determine the worst-case execution times (WCETs) of the applications. The predictability of SPM makes these WCETs easier to measure. This thesis presents a new method for allocating stack and global data to the SPM. It is the first method to make use of the special properties of non-escaping variables so as to increase the effective size of the SPM. Our insight is that many local variables of caller functions can be temporarily swapped out of the SPM while the callee function executes. Ours is also the first method to support profiled WCET measurements in the allocation strategy. Most previous SPM methods optimize only for the average-case execution time (ACET), despite the fact that SPMs are often used in real-time environments where the WCET is also important. This new memory allocation strategy is also the first to be WCET/ACET tunable, a feature that is particular useful for soft real-time systems. Only one previous work considers a WCET-targeted SPM allocator. That work, however, only applies to static WCET analysis tools. Such tools are difficult to program and are not widely used. Also, they only have application to the most safety-critical of real-time systems. In contrast, our approach is the first to employ measurement-based WCET analysis (such as is most commonly used in industry) for SPM allocation.