Friction is a nonlinear phenomenon which has destructive effects on performance of control systems. To obviate these effects, friction compensation is an effectual solution. In this paper, an adaptive technique is proposed in order to eliminate limit cycles as one of the undesired behaviors due to presence of friction in control systems which happen frequently. The proposed approach works for n...

The reliability and durability of an ultrasonic motor is usually determined by wear at the contact interface between a drive and a driven element, due to its driving mechanism. Wear control is therefore essential as the key design input to achieve ultimate performance of the ultrasonic motor. In this paper, a high precision and small precise positioning linear stage with an ultrasonic motor as ...

Position information in indoor environments can be procured using diverse approaches. Due to the ubiquitous presence of WLAN networks, positioning techniques in these environments are the scope of intense research. This paper explores two strategies for space partitioning when utilizing cascade-connected Artificial Neural Networks (ANNs) structures for indoor WLAN positioning. A set of cascade-...

In rapid static or kinematic positioning, especially with single frequency and shorter period GPS phase observations, the normal matrix may be weak multicollinear since the GPS satellite’s positions and geometries are changing slightly. Therefore the conventional least squares float solution may cause large biases due to the weak multicollinearity and thus make the ambiguity search techniques f...

A new sensor based homing integrated guidance and control law is presented to drive an underactuated autonomous underwater vehicle (AUV) towards a fixed target, in the horizontal plane, using the information provided by an Ultra-Short Base Line (USBL) positioning system. Almost global asymptotic stability (AGAS) is achieved, both in the absence of external disturbances and in the presence of co...

Positioning technology to track a moving object is an important and essential component of ubiquitous computing environments and applications. An RFID-based positioning system using the k-nearest neighbor (k-NN) algorithm can determine the position of a moving reader from observed reference data. In this study, the optimal detection range of an RFID-based positioning system was determined on th...

Positioning technology is a core component of the ubiquitous computing environment. Radio Frequency IDentificaiton (RFID) is recognized as a powerful means of replacing not only barcodes for product identification but also conventional positioning systems in unfavorable situations such as indoor and obstacle-laden sites. The objective of this study was to determine the design parameters of an R...

Recent developments in optimal observer design for dynamic positioning have led to application of contraction analysis. In this paper a theoretical method for nonlinear optimal observer design and a suboptimal observer using a state-dependent Riccati equation approach are presented. The observer will be compared to an existing observer and its properties and performance is discussed. Early obse...

A new sensor based homing integrated guidance and control law is presented to drive an underactuated autonomous underwater vehicle (AUV) towards a fixed target, in the horizontal plane, using the information provided by an Ultra-Short Base Line (USBL) positioning system. Almost global asymptotic stability (AGAS) is achieved, both in the absence of external disturbances and in the presence of co...