Recently, several researchers have studied a vector tracking loop, such as a vector delay lock loop (VDLL) and a vector frequency lock loop (VFLL), to obtain an improved tracking performance in GPS receiver [1~6]. The vector based tracking loop technique uses the correlation of each satellite signal and user dynamics. The receiver with the vector tracking loop can get enough total signal power ...

In this paper, we consider performance output tracking for a boundary controlled one-dimensional wave equation with possibly unknown internal nonlinear uncertainty and external disturbance. We first show that the open-loop system is well-posed and then propose a disturbance estimator. It is shown that the disturbance estimator can estimate successfully the total disturbance that consists of int...

Reliability is the most critical characteristic of space missions, for example in capturing and tracking moving targets. To this end, two methods are designed to track sunlight using solar remote-sensing instruments (SRSIs). The primary method use offset angles guide mirror closed-loop tracking, while alternative angles, calculated from satellite attitude, vector, mechanical installation correc...

In this article, we propose a trajectory tracking control method for piezoelectric actuators (PEAs) based on long short-term memory neural network (LSTM-NN). Different from traditional framework where is used to approximate the open-loop PEA dynamics, LSTM-NN establish mapping between actual and reference of closed-loop PEA, leading Closed-LSTM framework. With framework, trained modify compensa...

In the most described maximum power point tracking (MPPT) methods in the literatures, the optimal operation point of the photovoltaic (PV) systems is estimated by linear approximations. However, these approximations can lead to less optimal operating conditions and significantly reduce the performances of the PV systems. This paper proposes a new approach to determine the maximum power point (M...

The tracking control accuracy of the piezoelectric actuator (PEA) is limited due to its inherent hysteresis nonlinearity. A new piezoelectric-actuator model is synthesized based on two first-order transfer systems in parallel with two tuned parameters determined from one experiment. Two open-loop tracking controllers are implemented with the proposed model to compensate the hysteresis of linear...

Assessment of performance in tracking set-point changes for single loop systems is presented. In contrast to the works that used stochastic performances, the current assessment uses a deterministic performance measure, i.e. the integration of absolute tracking errors (abbr. IAE). A benchmark system that has an open loop transfer function (abbr. OLTF) comprised of one LHP zero, one integrator, a...

This work proposes a systematic two-degree freedom control scheme to improve the reference input tracking and load disturbance rejection for an unstable magnetic levitation system. The proposed control strategy is a two-step design process. Firstly, a proportional derivative controller is introduced purposely to get the desired set-point response of the magnetic levitation system and then, an i...

The control feel of the master controller in a telemanipulation system has a critical effect on human-machine system performance. Many theoretical and practical human factors issues on hand controller design and selection remain to be explored. In this paper, two types of hand controllers, elastic versus isometric rate controllers, were studied in a 6 degree-of-freedom pursuit tracking experime...

[1] Global Positioning System (GPS) radio occultation (RO) is a space-borne remote sensing technique providing accurate, all-weather, high vertical resolution atmospheric parameters, including pressure, temperature and humidity in the troposphere and stratosphere. In the moist lower troposphere (LT) RO encounters known problem related to the phase-locked loop (PLL) tracking technique applied in...