Abstract This research provides a solution to the challenging problem of enforcing periodic or cyclic motion in underactuated systems, even when upper position is an unstable equilibrium point open-loop system. Here, we present tracking control cart-pendulum system, where pendulum forced oscillate around its upward position. A two-relay controller was used generate desired trajectory, which loc...

Coordination is one of the keys for the success of open source software (OSS) communities because geographically distributed members need to collaborate on their work using communication tools (e.g., mailing lists, bulletin board systems, bug tracking systems, and so on). In this paper, we investigated the informal social structure among developers and users by analyzing two mailing lists of de...

Barium Strontium Titanate (BST) varactors utilized in a VCO demonstrate unique tuning characteristics compared to junction varactors. A 2.7 GHz microstrip line VCO operates in a tracking phaselock loop configured as an X4 frequency multiplier. BST oscillator tuning and the effect on loop dynamics is observed by the intentional design of an under damped system. Oscillator noise correction and pe...

This paper presents a new observer based fuzzy terminal sliding mode controller design for a class of fractional order nonlinear systems. Robustness against uncertainty and disturbance, the stability of the close loop system and the convergence of both the tracking and observer errors to zero are the merits of the proposed the observer and the controller. The high gain observer is applied to es...

Comprehending Open Source Software (OSS) projects requires dealing with huge historical information stored in heterogeneous repositories, such as source code versioning systems, bug tracking system, mailing lists, and revision history logs. In this paper, we present Binoculars, a prototype tool which aims to provide a platform for graph based visualization and exploration of OSS projects. We de...

This article presents a closed-loop transmitter for wireless power transfer with automatic resonance frequency tracking to maintain high efficiency in the over-coupled region. The consists of source oscillator, amplifier (PA), PA driver, matching network, and feedback circuitry. By injecting resonant output coupled antenna coils into oscillator form positive loop, is injection-locked functions ...

This paper presents an observer-based robust control for mechatronic systems that utilize a surface-mounted permanent magnet synchronous motor (SPMSM). A mechatronics system with SPMSM typically comprises mechanical moving part (outer-loop) and power converter (inner-loop) to drive the motor. We explain dynamic modeling of provide brief discussion on disturbances in SPMSM. cascaded tracking err...

The additive noise response of a charge pump phase-locked loop in the synchronous mode of operation has been studied. In order to determine the tracking and noise performances of the loop, mean square values of tracking error and local oscillator phase jitter have been analytically obtained. Analytical results agree well with the simulation results obtained here and elsewhere [3]. The analysis ...

This report presents the results of comparing four different frequency estimation schemes in the presence of high dynamics at low carrier-to-noise ratios. The comparison is based on measured data from a hardware demonstration. The tested algorithms include a digital phase-locked loop, a cross-product automatic frequency tracking loop, an extended Kalman filter, and finally, an FFT-aided cross-p...