Academic literature on the topic 'Stationary motor generator'

The past decade has seen advances in wireless network technologies and an explosive growth in the diversity of portable computing devices such as laptop computers, handheld personal computers, personal digital assistants (PDAs), and smart phones with Internet access. Wireless networking technologies and portable devices enable users to access information in an “anytime, anywhere” fashion. For example, a mobile user (MU) on the highway may query local weather, traffic information, nearby gas stations, next rest areas, or restaurants within 10 miles. Such new demands introduce a new type of services, location-based services (LBS), where certain location constraints (e.g., the user’s current location) are used in the service provision. The idea of queries with location constraints is originally introduced by Imielinski and Badrinath (1992), in which mobile users are likely to query information relating to their current positions, leading to the need for LBS. Such services are also termed as location dependent information services (LDIS) in Lee, Lee, Xu, and Zheng (2002). LBS system is the context sensitive systems in a mobile computing environment that consider the user’s location as a significant and dynamic factor affecting the information and services delivered to the users. The major LBS applications include: • Destination guides with maps, driving directions, and real time prompt • Location-based traffic and weather alerts • Wireless advertising and electronic coupons to nearby mobile devices • Movie, theatre and restaurant location and booking • Store locating applications helping users to find the desired services • Telematics-based roadside assistance (e.g., OnStar from General Motors) • Personal content and messaging (Live Chat with friends) • Mobile Yellow Pages provide local information • Information Services (News, Stocks, Sports) • E911: (Wireless carriers provide wireless callers’ numbers and locations.) Generally, LBS services can be classified into three general categories: telematics LBS, Internet LBS, and wireless LBS (Telc). Telematics LBS is the integration of wireless communications, vehicle monitoring systems, and location devices. Telematics LBS applications include automated vehicle location, fleet tracking, online navigation, and emergency assistance. For example, a trucking company can track all their fleet, proactively warn about traffic ahead, and estimate the arrival time. Commercial LBS providers are beginning to offer important management applications that help direct vehicle fleets and ensure optimal usage of key assets. Telematics LBS is a multibillion dollar service industry and is currently the largest segment of the LBS market (Telc). Internet LBS provide Internet users the services relevant to their specified locations. Because they use a user-specified location instead of the user’s current location, no positioning technology is required. For example, one can find turn-by-turn driving direction from one location to another and search for tour information about the destination. These services are targeting applications with stationary users, relatively powerful computers, and reliable network connections. As a result, Internet LBS support sophisticated services, such as local business searching and comparison, trip planning, online virtual tours, and so forth. Wireless LBS deliver location relevant content to cell phones, PDAs, and other wireless devices. Equipped with automated positioning technologies, MUs can query local weather, nearby traffic information, and local businesses close to them. For example, a user can search neighboring post office or coffer shop from the PDA. The wireless LBS market is currently in a nascent stage, but it will potentially become the largest segment of the LBS market. The deployment of third generation (3G) mobile network, which support handsets that are both mobile and location sensitive, will lead to more wireless LBS subscribers and more useful LBS applications.

Most gas turbine generators rely on an automatic-engaging, free-wheel clutch to connect a starting motor to accelerate the gas turbine generator from zero to some intermediate speed to enable ignition and then provide torque assistance to a higher speed until the gas turbine is self-sustaining. The U.S. Navy has used various designs of starter motors and clutches for its gas turbine fleet. In addition, there has been a requirement to periodically borescope each gas turbine and this has necessitated removal of the starting system and clutch assembly in each instance. This paper examines the U.S

Passive infrared (PIR) sensors are the most popular deployed sensors in building lighting control for individual presence detection. However, PIR sensors are motion detectors in nature, responding only to incident radiation variation, which lead to false negative detections, inaccurate occupancy estimation, and uncomfortable lighting swings, short lifetime of the equipment, and waste of energy. In this study, a shutter driven by a Lavet motor PIR (LAMPIR) sensor is developed for presence detection for both stationary and moving occupants. Building off our previous work on chopped PIR (C-PIR) a

A polygon motor consists of several mirror faces and it is one of the core components for a laser beam printer and a copier. Under high-speed rotation, aeroacoustic noise with a peak frequency of rotational speed times the number of mirror faces and its harmonics is prominently generated from a polygon motor covered with a casing. This paper describes a method to predict such noise that is generated from the flow in between the rotating mirror and stationary casing, propagates through the casing and is radiated into the ambient air. The unsteady flow is firstly computed by large-eddy simulatio

Electric generators and synchronous motors with static excitation use rotating slip rings (also known as collector rings) and stationary carbon brushes to transfer the field current from the stationary exciter to the rotating generator field. The carbon brushes experience wear from both mechanical friction and electrical contact with the rings. Therefore, the brushes need to be periodically inspected and replaced. This is often the most frequent maintenance activity for an electric generator. It is generally recognized that if brushes are not changed when worn down, this can result in a damagi

Abstract A fuel and engine management system have been successively applied to a 4.5L spark-ignition gaseous-fueled engine used for stationary power generation applications up to 80 kW. The system operates on low-pressure commercial grade natural gas or liquid propane gas and governs engine speed at either 1500 or 1800 rpm, for generator frequencies of 50 Hz and 60 Hz respectively. The fuel and engine management system consist of an engine control module, an electronically controlled fuel mixer, a fuel pressure sensor, and other supporting sensors/actuators. This new system replaces a legacy o

Abstract A method termed harmonic tracking is developed to recover time dependent gear motion from machine casing vibration. The harmonic tracking method uses short-time spectral generation and a subsequent set of algorithms to locate and track gear meshing frequencies as functions of time. The meshing frequencies are then integrated with respect to time to obtain the rotation of individual gears. More specifically, spectral generation is performed using the discrete Fourier transform, and the locating and tracking algorithms involve locating tones in each short-time spectrum and tracking them

This paper presents the electromagnetic design and experimental validation of a new framework for linear permanent-magnet (PM) machines with magnetic levitation. In this framework, a single forcer, which can generate two force components in two perpendicular directions, consists of a stationary Halbach magnet array and two Lorentz coils with a phase difference of 90° or 270°. Any number of coil pairs can be attached on the same moving frame to work with a common magnet array or matrix, forming a linear or planar permanent-magnet motor. Key advantages of this framework are simple force calculat

Qualification shock testing has been completed for a new chilled water plant developed for the US Navy. The variable speed compressor at the heart of the chiller system includes a direct drive, high-speed permanent magnet (PM) motor, PM bias active magnetic bearings, and a backup bearing system. For MIL-S-901D shock certification, the chiller was mounted on a Navy floating shock platform (barge) and subjected to a standard sequence of four different shock impacts generated from high explosive charges from varying angles and standoff distances. The chiller was fully operational during three bla

Electroencephalography measures the sum of the post-synaptic potentials generated by many neurons having the same radial orientation with respect to the scalp. The electroen-cephalographic signals (EEG) are weak and often contaminated with different artifacts that have biological and external sources. Reliable pre-processing of the noisy, non-linear, and non-stationary brain activity signals is needed for successful extraction of characteristic features in motor imagery based brain-computer interface (MI-BCI). In this work, a signal processing technique, namely, empirical mode decomposition (E

This paper introduces the mechanism of a buoy-type wave energy converter (WEC) with a tuned inertial mass (TIM) mechanism. The TIM mechanism consists of a rotational mass and motor connected in series with a tuning spring. While it is common to control the current of the power take-off system, the stiffness of the spring is tuned in addition so that the inertial mass part resonates with the dominant frequency of the wave motion. The method to design the parameters to maximize the power generation capability is introduced and numerical studies for both narrowband and broadband sea states are ca