Aerodynamic control analysis in a canard configuration for a surface-to-surface missile

Special issue on applied neurodynamics: from neural dynamics to neural engineering

Energy Benefits of Electronic Controls at Small and Medium Sized U.S. Manufacturers

This paper describes a set of dynamic field tests performed on the Alfred Zampa Memorial Bridge (AZMB), also known as the New Carquinez Bridge, which is located 32km northeast of San Francisco on interstate Highway I-80. The AZMB, opened to traffic in November 2003, is the first suspension bridge in the United States with an orthotropic steel deck, reinforced concrete towers, and large-diameter drilled shaft foundations. The dynamic field tests described herein were conducted just before the bridge opening to traffic. They included ambient vibration tests, mainly wind induced, and forced vibration tests based on controlled traffic loads and vehicle-induced impact loads. Four different controlled traffic load patterns and seven different vehicle-induced impact load configurations were used in the forced vibration tests. The dynamic response of the bridge was measured through an array of 34 uniaxial and 10 triaxial force-balanced accelerometers deployed along the whole length of the bridge. These dynamic field tests provided a unique opportunity to determine the dynamic (modal) properties of the bridge in its as-built (baseline) condition with no previous traffic loads or seismic excitation. Such properties could be used to validate and/or update the finite element models used in the design phase of this bridge. They could also be used as baseline for future health monitoring studies of this bridge. At the end of the paper, the ambient vibration test data were used to identify the bridge modal parameters (natural frequencies, damping ratios, and mode shapes) using the data-driven stochastic subspace identification method.

Present paper attempts to review the literature related to design of P-I-D control for time delayed complex industrial process for single as well as for multivariable process with interaction considerations, their decoupler design and time delay compensators. General instrumentation of the industrial feedback control systems along with control system analysis has been covered. Also it covers, control features of some paper mill sub-processes like headbox operation, basis weight and retention. The importance of eliminating the effects of interactions, among the process control loops inside a multi input multi output industrial control system, has been discussed with the help of literature study. The importance of the process dynamics knowledge for designing a control system has also been investigated. This paper also investigates the significance and effectiveness of PID controllers through various literature studies. The problems of the classical PID controllers such as constraints, presence of disturbances etc.) can be removed by designing in combination with soft computing techniques. Moreover, possibility of further enhancements in the PID controller with the utilization of various schemes available, has been presented. The present status of control systems in industrial processes in terms of various control parameters such as stability, dead time compensation etc. has been presented and the future improvements have been stated.

Tutorial review on repetitive control with anti-windup mechanisms

Problems of synthesizing modern control systems -Intelligent Control Systems were researched.The original concepts of synthesizing Intelligent Control Systems for dynamic objects were presented, which were developed based on the P.K. Anokhin Functional Systems Theory.Various approaches on synthesis of perspective control systems for flight vehicles by utilizing Intelligent Elements were developed as well.Consequently, practical applications of Intelligent Control Systems were thus illustrated by presenting examples of perspective Pseudo-intelligent Control and Measurement Systems of flight vehicles.In the paper, all the functional structures proposed of Intelligent Control Systems have great practical implementary values and can be applied for synthesis of various control systems for diverse dynamic objects.

Numerical modelling and inverse analysis of continuous compaction control

This paper highlights the main functions of clutch automatic control systems. These are: forced clutch disengagement during gear shifting and when the engine falls below its minimum operating speed; forced clutch engagement under conditions of increasing engine speed or vehicle speed at a preset level or at a definite throttle position; adjustment of clutch friction torque, depending on the control parameter used. To achieve this, a closed-loop automatic control system is required. The system compares control signals with feedback from a selected parameter and generates commands for changing clutch friction torque. At present some automatic clutch systems use either the position of the accelerator pedal (‘Drivematic’ and ‘Guidosimplex’) or engine speed (ACTS) as the control parameter. The feedback parameter in these systems is the position of the clutch drive element. Comparison of the two systems shows that those using engine speed as the control parameter are more advanced, although their design is more complex. Engine speed is also used in the system of automatic electrovacuum friction clutch control (EPS) designed at the Central Automobile and Automobile Engine Scientific Research Institute (NAMI), but the principle of operation is totally different from existing systems. Particular features of this system are as follows: all necessary modes of automatic control are provided by only one multi-function electromagnet acting on the vacuum valve in the clutch actuating servo chamber; the feedback is dependent on the position of the clutch actuator and is provided by a spring acting on the armature of the valve drive electromagnet—the force of this spring changes in proportion to the position of the clutch actuator; clutch friction torque control as a function of engine speed is provided by changing the current strength in the electromagnetic winding—these changes are initiated by the electronic control unit of the automatic control system. To achieve the optimal performance of modern high-speed engines in combination with an automatic clutch system, all elements of the clutch control system must have minimal delay in converting input signals into control signals. This requirement resulted from an investigation of the EPS mathematical model comprising three non-periodic dynamic elements. The same results were experimentally proved when amplitude and phase frequency characteristics of the control system were measured. It was shown in particular that the time constants of dynamic elements must not exceed 0.04–0.06 s. This required the application of a brand new engineering circuit for designing the EPS electronic unit. The EPS system is now in mass production and is standard equipment for some models of small passenger cars manufactured in the former Soviet Union. The system has been patented in the United States, Japan, Germany, Great Britain, France and Italy.

The aim of this research is to apply vehicle dynamics control systems to mitigate the vehicle collision and study the effects of these systems on the kinematic behaviour of the vehicle’s occupant. An unique three-degree-of-freedom vehicle dynamics/crash mathematical model and a simplified lumped mass occupant model are developed. The first model is used to define the vehicle body crash parameters and it integrates a vehicle dynamics model with a vehicle front-end structure model. In this model, the anti-lock braking system and active suspension control system are co-simulated, and its associated equations of motion are developed. The second model aims to predict the effect of vehicle dynamics control systems on the kinematics of the occupant. The Lagrange’s equations are used to solve that model due to the complexity of the obtained equations of motion. It is shown from the numerical simulations that the vehicle dynamics/crash response and occupant behaviour can be captured and analysed quickly and accurately. Furthermore, it is shown that the vehicle dynamics control systems can affect the crash characteristics positively and the occupant behaviour is improved.

RF MEMS switch is characterized by its pull-in potential. Stiffness constant of cantilever beam plays an important role in determining its pull-in potential. Stiffness constant of the cantilever beam depends on its material properties, dimensions and geometrical shape. In this work variable width based stepped cantilever beam is proposed for reducing the pull-in potential. Mathematical (mechanical) modeling of such unconventional cantilever beam using conjugate-beam method is presented in this paper. For obtaining pull-in potential using mathematical modeling; a python script is developed whereas CoventorWare FEM tool is used for numerical simulation. It is found that pull-in potential obtained through mathematical modeling and numerical simulation are same. Moreover it is less than normal rectangular cantilever beam of the same length, width and thickness.

The Chulitna River Bridge is a 790-ft five girder, five-span steel bridge on the Parks Highway between Fairbanks and Anchorage, Alaska. This bridge was built in 1970 and widened in 1993. Under the no-live load condition, five support bearings are not in contact. Heavily loaded trucks often travel across this bridge to the oil fields in Prudhoe Bay, Alaska. A virtual finite element modeling, dynamic field testing of the “ambient vibrational response,” and structural health monitoring system are used to analyze, evaluate, and monitor the structural performance. As the first stage of the research, this article presents results from the dynamic testing and evaluation of the structural responses of the bridge. In the dynamic field testing, 15 portable accelerometers were placed on centerline along the bridge length to record the structural response, and an ambient free-decay response was used to evaluate the dynamic properties of the bridge structure. Natural frequencies and modal damping ratios were identified and characterized using Hilbert–Huang transform and fast Fourier transform methods. Compared with conventional approaches, this study demonstrates that (1) the Hilbert–Huang method was found to be effective and suitable for modal parameter identification of a long steel girder bridge using ambient truck loading; (2) the nonlinear damping was, for the first time, identified based on Hilbert–Huang transform’s amplitude–time slope; (3) modal frequencies are very sensitive to sensor location so their position should be optimized.

In this paper the authors propose a method for tuning proportional derivative control parameters using the particle swarm optimizer for dynamic environments. The process consists of the brake system in wind turbine plant. Each particle to reset its record of its best position as the environment changes, to avoid making direction and velocity decisions on the basis of outdated information. In this study designed and implemented an automatic brake control system based Proportional-Derivative Particle Swam Optimization (PD-PSO). The goal is to maintain the reliability of the wind turbine generator, safety systems and the application of control systems in the system is more appropriate. Wind turbine rotation speed is detected using a rotary encoder to transmit data to the microcontroller and further control signals sent to the servo motor which serves to reduce the rotational speed of the wind turbine rotational. In this study the PD control mode parameters based on PSO, from the experiment for each parameter set points, among others when the set point in 5 pulse per second (PPS), have gain Kip?=0.2812 and Kid=1.2459, maximum overshoot = 9 % and error steady state = 2 second. For set point 10 PPS, Kp=??0.4738 and Kd=0606, maximum overshoot = 914% and error steady state = 2 second. And last set point 15 PPS obtained parameter gain Kp=0.7147 and Kd = 2.0804, maximum overshoot=17% and error steady state 2 % criterion=2 second.

With the global widespread preference for low-floor trams, the expectation for tram riding comfort has been increasingly heightened. This paper identifies an abnormal riding comfort problem (ARCP, characterized by an excessive and W-shaped distribution of riding comfort) during dynamic field tests on a low-floor tram. To address ARCP, a multi-body dynamics model of the tram was constructed and validated its accuracy through dynamic field tests. By integrating track irregularities and wheel-rail contact analysis, the riding comfort index was assessed and reproduced the ARCP phenomenon. Linearization and time-domain integration studies were conducted on the mechanisms and measures to resolve the ARCP. The research findings reveal that the primary cause of the deterioration in the mean comfort index is the large amplitude of the track irregularity and the low equivalent conicity of the wheel-rail contact relationship. The main reason for the W-shaped distribution of riding comfort is the weaker inter-vehicle constraints and the lack of lateral energy-absorbing devices. Finally, optimization measures were proposed, including reducing the lateral stiffness of the second suspension, altering the carbody structural parameters, and modifying the inter-vehicle connection devices. This research enriches the study of tram dynamic performance and offers insights that may contribute to the resolution of ARCP.

Stable high quality of the purified water can be provided by adaptive control of water-treatment installations with the observer in a loop of the control system on the basis of observer of ion exchange processes. To obtain this goal the following problems have been solved: the hierarchic structure of water treatment system is developed; the system of water treatment quality criteria for ion exchange processes is developed; the created mathematical model of ionic exchange processes is functionally oriented to application in control system as an observer; methodologies of identification of a mathematical model of ionic exchange processes is developed; verification of the mathematical model of ionic exchange is performed on experimental-industrial basis; automatic control system of water treatment with observer in the loop is developed for low-waste installation of a heat supply system. Water resources that are widely used in the modern industry rarely meet the requirements of direct applications. Impurities contained in natural water are removed at water treatment installations (WTI) implementing technological processes chain, and ensuring water quality that is relevant to the technical regulations, sanitary rules and norms. This leads to the important role of the WTI as a subsystem in the system structure of the production and consumption of heat and electricity. Decreasing in the quality of treated water leads to huge costs for the restoration of the main energy-producing equipment - steam generators, turbines, and consumers' technology systems - heat exchangers, pipelines. Costs for improvements of WTI are significantly lower than the cost of liquidation of technological failures consequences. The application of currently developed technologies for the production of purified water, consisting of the processes for removal of suspended, colloidal, molecular-dispersed impurities and gases is constrained by the instability and uncertainty in source water quality, uncertainty of market demands and technological modes instability. The problem solution can be based on system analysis using a systematic structural mathematical modeling and identification of water treatment processes with the help of observer in the circuit of the automatic control system (ACS) of WTI in order to provide an effective control under conditions of uncertainty (1-3). Figure 1 presents a structural diagram of an adaptive ACS for regulating the quality of feed water at large thermal power plants. The loop of the ACS contains the observer which is based on functionally oriented mathematical model (FOM) of ion-exchange water treatment and includes also a mathematical model of the pH index to determine the components of alkalinity; mathematical model of the ion couples concentration; This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

To overcome the oscillations of the individual metering control system, a control scheme matrix including eight active damping methods is conducted and compared, with different signal feedback and different valve regulation. Through mathematical modeling and numerical simulation, the comparison result provides a guideline to determine a proper control scheme considering damping capacity, anti-disturbance ability, and availability for different applications. Considering the limitations of these damping methods, an inlet-outlet combined damping compensator is proposed, in which the inlet valve and the outlet valve are regulated simultaneously. Separate damping compensators for the inlet and outlet valves are designed, and the determination criterion of compensation parameters is presented. The benefit is that the additional dynamic behavior caused by pressure feedback is reduced to improve the anti-disturbance ability. A comparative simulation study using a 20-ton excavator was carried out under different working conditions. The results show that the proposed method has a similar oscillation damping with the traditional method under a given velocity command. More importantly, the proposed method reduces the velocity oscillation by additional 24.3%–28.5% and reduces the pressure oscillation by additional 5.2%–21.3% under sudden external disturbance.