Effect Of Controller Gain Research Articles

Pinning control of simplicial complexes

In this paper, pinning control of simplicial complexes is investigated. The D-dimensional simplicial complex can be successfully pinned to a desired state (i.e., an equilibrium of the intrinsic dynamics) under the proposed control scheme. The local stability of synchronization in the pinned simplicial complex is analyzed and discussed. The relationship between pinning synchronization and the individual dynamics, higher-order structures, coupling strengths, as well as the control strategy is established. Moreover, the effects of control gain and the number of controlled nodes on synchronizability are examined in detail. The obtained results can provide valuable references for designing optimal higher-order networks in practical applications.

Active vibration control of smart porous conical shell with elastic boundary under impact loadings using GDQM and IQM

In this paper, the active damping control of the porous metal foam truncated conical shell with smart material macro fiber composite (MFC) is studied. Suppose the shell has arbitrary elastic supported edges, and is subjected to the impact loadings. The elastic supported edges can be achieved by virtual spring technique. Adopting the elastic constraint boundary condition, various classical boundaries can be easily realized by varying the value of the spring stiffnesses. Along the thickness direction, there are three types of porosity distributions of truncated conical shell being considered, and they are nonuniform symmetric, uniform and nonuniform asymmetric distribution, respectively. The sensor layer MFC-d31 and the actuator layer MFC-d33 are applied in the vibration control system. According to the first order shear deformation theory (FSDT) and energy principle, the dynamic equation of the system under electrostatic–mechanical​ coupling is derived. Then it is discretized into ordinary differential equation by generalized differential quadrature method (GDQM). The output charge applied to the sensor can be solved by integral quadrature method (IQM). The convergence and validation of the formulation and numerical calculation are studied by the comparisons between the present solutions and those from the literatures, ANSYS and COMSOL for the truncate conical shell with classical boundary conditions, respectively. Suppose the impact loadings acting on the porous truncated conical shell are step loading and decreasing loading, respectively. The velocity negative feedback approach is employed to diminish the amplitude of the transient response and achieve the active damping control. Then the effects of control gain, external excitation, semi-vertex angle and spring stiffness on the transient response control of the conical shell are studied in detail.

Cascaded Nine-Level Inverter for Hybrid-Series Active Power Filter, Using Industrial Controller

An industrial controller, specifically designed for two- and three-level converters, was adapted to work on an asymmetrical nine-level active power filter (APF). The controller is now able to make all required tasks for the correct operation of the APF, such as current-harmonic elimination and removal of high-frequency noise. The low switching-frequency operation of the nine-level converter was an important advantage in the application of the industrial controller. In addition, with the nine-level filter, switching losses were significantly reduced. The filter was designed to work as voltage source and operates as harmonic isolator, improving the filtering characteristics of the passive filter. The control strategy for detecting current harmonics is based on the “ p-q theory ” and the phase-tracking system in a synchronous reference frame phase-locked loop. The dc-link voltage control is analyzed together with the effect of controller gain and delay time in the system's stability. Simulations for this application are displayed and experiments in a 1-kVA prototype, using the aforementioned industrial controller, were tested, validating the effectiveness of this new application.

Output Feedback Controller Design for a Class of MIMO Nonlinear Systems Using High-Order Sliding-Mode Differentiators With Application to a Laboratory 3-D Crane

This paper addresses the problem of output feedback control design for a class of multi-input-multi-output (MIMO) nonlinear systems where the number of inputs is less than that of outputs. There are two difficulties in this design problem: (1) too few control inputs will not generally allow independent control over all outputs and (2) the state of the system is not available for measurements, and only the outputs are available through measurements. To address the first issue, a practical output feedback control problem is formulated, aiming to regulate only part of the outputs, and a controller structure with two design components in all or some chosen control inputs is proposed. To cope with the second difficulty, the recently developed high-order sliding mode differentiators (HOSMDs) are used to estimate the derivatives of the outputs needed in the controller design. With the derivatives estimated using HOSMDs, an output feedback controller is designed using the backstepping approach. Stability results are established for the designed controller under certain conditions. In order to test the applicability of the proposed output feedback controller in practical industrial problems, experiments are carried out though implementing the controller on a laboratory-scale 3-D crane. The experimental results are presented and reveal the advantage of the proposed controller structure, as well as the effect of controller gain and sampling periods.

The interaction of control gain and vibration with continuous manual control performance

The interaction of the effects of control gain and 4 Hz vertical (z-axis), whole-body vibration at 0·75 m/s2 rms on human operator performance in a simple manual tracking system was investigated with four different controls. The controls were isotonic (displacement) and isometric (force) joysticks and knobs. Performance analysis includes calculation of closed-loop human operator transfer functions, components of error correlated with the tracking input and vibration and operator generated noise. The optimum control gains for minimizing tracking error under vibration were found to be lower than in static conditions due to increases in vibration-correlated error and operator-generated noise, which both tend to be proportional to control gain.

Multiplicity of the steady in the fluidized bed reactors—III: Yield of the consecutive reaction A → B → C

The simplified non-isothermal model for fluidized bed reactors developed earlier (Parts I, II) is extended here to the case of exothermic consecutive reaction, A → B → C. It is shown that simple adiabatic operation is not possible when the second reaction, B →- C is relatively fast because the desired operating temperature corresponds to an unstable steady state. A simple control scheme is suggested to stabilize the unstable steady state. Conditions for the existence of unstable steady state giving rise to limit cycle behaviour are discussed using local stabdity analysis. Limit cycles are shown on the phase plane and the effect of controller gain is investigated.