Hysteresis and nonlinearity exist in most valves that are utilized in building HVAC systems, such as in cooling or heating coil valves. The hysteresis mainly comes from the manufacturing clearance in an actuator gearbox and nonlinearity in the variation of the regulated flow with respect to control signal originates from valve design. The combination of valve hysteresis and nonlinearity poses s...

This paper considers the problem of adaptive output feedback tracking control for a class of nonstrict-feedback nonlinear systems with unknown time-varying delays and unknown backlash-like hysteresis. Fuzzy logic systems are used to estimate the unknown nonlinear functions. Based on the Lyapunov–Krasovskii method, the control scheme is constructed by using the backstepping and adaptive techniqu...

Synthesis of BaFe12O19 magnetic nano particles via precipitation in different pH conditions have been reported. The certain molar ratio of Fe/Ba = 12 selected and sodium hydroxide was used as a precipitant agent. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and vibrating sample magnetometer (VSM) were used to consider the structural, morphological and magnetic properties of bariu...

Slow relaxation of the magnetization and hysteresis loop were observed in the antiferromagnetic ordered phase of a two-dimensional framework based on one-dimensional Co(II) magnetic chains.

This paper presents the development and initial results of a controller based on a novel rate-dependent hysteresis model. The controller has been developed for “Micron,” a microsurgical instrument designed to sense and actively cancel tremor and other undesired motion during vitreoretinal intervention. To accomplish this, Micron uses a three-degree-of-freedom parallel manipulator with piezoelec...

Dynamic phase transition in diluted kinetic Ising model in two dimensions has been studied in presence of external time dependent oscillating magnetic field applying Glauber Monte Carlo spin flip dynamics. A dynamic phase transition from a dynamically ordered to dynamically disordered ferromagnet is identified studying dynamic order parameter against temperature for different concentrations of ...

A disturbance rejection based control approach, active disturbance rejection control (ADRC), is proposed for hysteretic systems with unknown characteristics. It is an appealing alternative to hysteresis compensation because it does not require a detailed model of hysteresis, by treating the nonlinear hysteresis as a common disturbance and actively rejecting it. The stability characteristic of t...