As the weak link in global navigation satellite system (GNSS) signal processing, the phase-locked loop (PLL) is easily influenced with frequent cycle slips and loss of lock as a result of higher vehicle dynamics and lower signal-to-noise ratios. With inertial navigation system (INS) aid, PLLs' tracking performance can be improved. However, for harsh environments with high dynamics and signal at...

A trajectory tracking problem for the three-dimensional kinematic model of a unicycle-type mobile robot is considered. It is assumed that only two of the tracking error coordinates are measurable. By means of cascaded systems theory we develop observers for each of the error coordinates and show the K-exponential convergence of the tracking error in combined closed-loop observer-controller syst...

Automated segmentation and tracking of cells in actively developing tissues can provide high-throughput and quantitative spatiotemporal measurements of a range of cell behaviors; cell expansion and cell-division kinetics leading to a better understanding of the underlying dynamics of morphogenesis. Here, we have studied the problem of constructing cell lineages in time-lapse volumetric image st...

In Compass/INS integrated navigation systems, feedback inertial navigation solutions to baseband tracking loops may eliminate receiver dynamic effects, and effectively improve the tracking accuracy and sensitivity. In the conventional inertially-aided tracking loop, the satellite-receiver line-of-sight velocity is used directly to adjust local carrier frequency. However, if the inertial solutio...

A geometric control is proposed for the trajectory-tracking of a quadrotor unmanned aerial vehicle with suspended load. The plant to be controlled modelled by using Euler–Lagrangian equations, and it linearised around zero swing angles load are supposed unmeasurable, they estimated state observer. controller design in inner–outer loop framework, where outer basically implemented internal model ...

The circadian clock controls 24-h rhythms in many biological processes, allowing appropriate timing of biological rhythms relative to dawn and dusk. Known clock circuits include multiple, interlocked feedback loops. Theory suggested that multiple loops contribute the flexibility for molecular rhythms to track multiple phases of the external cycle. Clear dawn- and dusk-tracking rhythms illustrat...

Free-space laser communication is a promising technology to meet the demand for cost-effective wideband support for future NASA missions. JPL has begun construction at the Table Mountain Facility in California of a 1-meter telescope system, known as the Optical Communication Telescope Laboratory (OCTL) and capable of tracking spacecraft from low Earth orbit to deep space, for development and va...

PN code tracking is one of the most important factors that affect the performance of spread spectrum receivers. It is desirable to maintain PN code tracking for a long period of time and with high accuracy. This paper presents a non-coherent digital delay-locked loop (DLL) for code tracking in direct-sequence spread spectrum (DS-SS) systems. The proposed technique utilizes three non-coherent co...

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...