By Topic

Proceedings of the IEEE

Issue 5 • Date May 1973

Filter Results

Displaying Results 1 - 25 of 43
  • [Front cover and table of contents]

    Page(s): c1
    Save to Project icon | Request Permissions | PDF file iconPDF (353 KB)  
    Freely Available from IEEE
  • Scanning the issue

    Page(s): 516 - 517
    Save to Project icon | Request Permissions | PDF file iconPDF (244 KB)  
    Freely Available from IEEE
  • Transportation, automation, and societal structure

    Page(s): 518 - 525
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1237 KB)  

    Only when we learn to understand much better the dynamic interaction between new transportation systems and the structure of our communities can we take full advantage of transportation's potential as a really effective tool in our quest for a finer quality of life for our citizens. The opportunity to do so is much enhanced by the recent rapid evolution in transportation from its centuries-old pattern of unconstrained growth paced by key advances in propulsion and new rights of way to a new age of finesse in which automation will bring, from existing rights of way, higher capacity, greater safety, and far better service at lower cost through automated system and total-trip management. In parallel, the discipline that has helped us predict well the dynamic behavior of such mostly physical systems as air-traffic control may add some helpful insight into such critical questions as the long-range effects of transportation on urban structure, where nontechnological factors dominate. Leadership belongs to the communities; the federal role is to provide support in generic ways. It is hoped that new Department of Transportation programs in technology-and-planning-tool sharing and in university support will be helpful. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Freeway traffic surveillance and control

    Page(s): 526 - 536
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1174 KB)  

    In the past decade, automatic freeway surveillance and control systems have been introduced in several cities in the United States. Effective use of the hardware that has been implemented requires a sound mathematical basis for evaluation and optimization studies. In this paper, the nature of freeway congestion and the structure of systems which have been implemented to relieve this congestion are discussed. Mathematical models of freeway traffic which allow consideration of on-ramp metering control are developed. Finally, several freeway traffic-control problems are discussed, current approaches are described, and formulations of improved (optimal) approaches are developed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Freeway-traffic data processing

    Page(s): 537 - 541
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB)  

    Two basic data processing problems associated with freeway traffic are formulated: estimation of traffic variables (section mean speed and density) and detection of occurrence of an incident or accident within a given section of the road. The existing traffic sensors and the current estimation techniques and their shortcomings are reviewed. Stochastic models for traffic variables are developed and used to design optimum recursive estimators. The incident detection problem is introduced as a potential area where many interesting research topics exist. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • TANA—An operating surveillance system for highway traffic control

    Page(s): 542 - 556
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1878 KB)  

    A complete surveillance and traffic control electronic system was designed and is being put into operation in a newly built urban tollway in Naples, Italy. In this system, named TANA after the tollway name (TAngenziale di NApoli), information is collected from several hundred loop detectors placed along the highway (on each lane every 250 m) and is relayed to a Central Control Room, where it is processed in real time by a digital computer. As a result, traffic conditions are continuously displayed to operators, and useful information is given to motorists through automatically steered variable-message signs, which on the tollway display conditions of traffic ahead, conditions of the roadway, state of traffic on the exit ramps, and outside the tollway, information on the state of entrance ramps and on the conditions of traffic in given sections of the tollway. Strategies for the automatic incident detection carried out by the system are described. The main purposes of TANA system are the achievement of maximum safety in critical points such as tunnels and entrance ramps (where access is controlled by means of automatically steered tunnel controllers and ramp controllers), the decrease in number and importance of multiple accidents, the optimization of traffic flow in the tollway and in the interchanges with the urban network, and the possibility for the users to take educated decisions based on the knowledge of traffic conditions. Safety features are assured even in case of a fault in the central computer or in the telecommunications system, by means of local analog devices, operating in standby. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmission properties of wayside communication systems

    Page(s): 556 - 561
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (588 KB)  

    Some transmission properties of wayside communication systems are discussed. These properties are common to all the wayside communication systems proposed for use on the high-speed ground transportation (HSGT) system. This study considers the method of echo theory, relating the ripple of the phase and amplitude response to the noise which may be produced in the channels. The noise sensitivity suggests its use as a criterion of line performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Continuous-access guided communication (CAGC) for ground-transportation systems

    Page(s): 562 - 568
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (669 KB)  

    Electromagnetic open-guiding structures, or surface waveguides, for continuous-access guided communication (CAGC) and obstacle detection ("guided radar"), are described for use in ground transportation, such as railways, highways, and more advanced guided systems. The experimental and theoretical work at Queen's University on surface-wave devices and their application to obstacle detection are reviewed in detail. It is concluded that there is considerable promise in these techniques and that obstacle detection, in particular, deserves much more attention than it appears to have received. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Baseline specifications for a magnetically suspended high-speed vehicle

    Page(s): 569 - 578
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1117 KB)  

    Baseline specifications for a magnetically suspended vehicle capable of 300 mi/h (483 km/h) operation are given. The magnetic forces (lift, drag, and lateral) on a superconducting coil moving over an aluminum guideway are shown. The basic features of the associated cryogenics are presented along with a discussion of the cryogenic refrigeration requirements. Vehicle dynamics and the resultant ride quality over roadbeds of various roughnesses are analyzed. Thrust requirements for the propulsion system are specified, and both the linear induction motor and the linear synchronous motor are considered. Several guideway configurations are suggested and the significant properties of each are noted. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characteristics of superconductive magnetic suspension and propulsion for high-speed trains

    Page(s): 579 - 586
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (567 KB)  

    Theoretical analyses are carried out on a magnetic suspension and a linear synchronous motor, both utilizing superconducting magnets. The derived theory is applied to the studies of the high-speed train models. In the suspension system investigated here, the roadbed is equipped with normal conducting coils. The magnetic lift force is found to be pulsating, and a design criterion for eliminating the pulsation components in the lift force is derived. An improved suspension system is proposed, which consists of a "ladder-type conductor" in the roadbed. This new system is investigated theoretically. An end effect of the suspension system is also studied. In the linear synchronous motor, the methods of minimizing reaction forces are derived. The combined magnetic suspension and propulsion system is analyzed. It is found that the influence of the track loops for the suspension on the linear synchronous motor is not very significant. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design principles for magnetic levitation

    Page(s): 586 - 598
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1481 KB)  

    General relations and limitations pertinent to the design of an inductive magnetic suspension system are derived. It is shown that in order to reduce magnetic drag we must increase the vehicle field and decrease the guideway currents. But this then produces a stiff suspension unless we are willing to increase guideway cost. Reasonable and consistent design objectives are shown to be: vehicle natural frequency for heave≃1 Hz without secondary suspension; suspension power lossessime;10 kW/ton (L/D=120 at 270 mi/h); aluminum requirements≃80 kg/m for a dual guideway. It was shown to be theoretically possible to operate at arbitrarily low speeds by using either a superconducting guideway or a feedback control system for short distances near terminals. Between terminals the guideway might resemble a parallel-wire transmission line with a thin conducting sheet between the wires. The design of an active-guideway linear synchronous motor is discussed and shown to be capable of supplying 5 MW of power at efficiencies of about 85 percent and a power factor of 0.5. For a dual guideway the armature windings require about 40 kg/m of aluminum, but no steel. The total cost of the maglev portion of a 120 m/s (268 mi/h) high-speed ground transportation system is estimated to be about 1 million dollars/km, with at least half of this related to propulsion and power distribution and control. If speed is reduced to 90 m/s (202 mi/h), substantial economies are possible. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Magnetic shielding for magnetically levitated vehicles

    Page(s): 598 - 603
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (593 KB)  

    The magnetic shielding required for magnetically levitated vehicles is discussed. Shielding is needed to protect passengers in a vehicle from stray dc magnetic fields coming from the superconducting dipoles carried by the vehicle. In addition, the superconducting dipoles must be shielded against various ac magnetic fields. Here we consider shielding of ac magnetic fields generated by the propulsion windings for the case of a linear-synchronous-motor active guideway. Protection for passengers against magnetic fields is necessary as there are at present no data upon which to base a human tolerance of magnetic-field intensity. It is shown here that in a magnetically levitated vehicle where the space to be shielded is large and where the weight of shielding is a prime concern, active shielding, in which compensation dipoles generate a canceling magnetic field, is superior to passive shielding, which uses iron plates. At the floor of the passenger cabin of a proposed vehicle, the magnetic field, without compensation, is as high as 0.03 T. Compensation dipoles, comparable in size to and placed 0.5 m above the main dipoles, increase the total conductor requirement by about ⅓ to bring the magnetic field at the floor of the passenger cabin below a level of 0.005 T. To achieve the same result by passive shielding, an iron plate or equivalent up to 2 cm thick must cover the floor of the passenger cabin, resulting in at least a 10 000-kg increase in the total weight for a 100-passenger vehicle. We therefore strongly recommend active shielding. At 100 Hz, a peak ac field of more than 10-5T cannot be tolerated in the superconducting dipoles of a vehicle as hysteresis and eddy-current losses within the conductor become excessive. The ac field reaching the main dipoles from the propulsion windings in the guideway can be as high as 10-3T without shielding. An aluminum sheet of 2-mm thickness kept at 4.2 K attenuates the field and makes ac superconductor losses negligible while keeping the eddy-current losses in the sheet to an acceptable level. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evacuated tube vehicles versus jet aircraft for high-speed transportation

    Page(s): 604 - 616
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1511 KB)  

    A preliminary investigation has been made of the potentialities of a high-speed low-loss transportation which could be competitive with the air-transport system. This system, called the MEL (magnetic-suspension, evacuated-tube, linear-motor-propulsion) system, employs passenger-carrying vehicles vertically supported by permanent magnets and laterally stabilized by an electro-magnetic servosystem, with no physical contact between vehicle and surroundings. Aerodynamic drag is reduced by two orders of magnitude (compared to operation in open atmosphere) by evacuation of the subterranean tube in which the vehicle travels. Expected magnetic drag at 270 m/s (600 mi/h) is small compared to aerodynamic drag. Stable contactless suspension was achieved with a model, but track length limited testing to low speeds. A linear motor is used for propulsion in the proposed system; since the low drag permits extensive coasting, only a small fraction of the track-mounted primary requires energization. Assuming magnetic drag negligible compared to aerodynamic drag at 270 m/s, a 1-percent reduction in coasting velocity would occur in approximately 85 km. The ultimate speed of this system will probably be determined by ground stability, track linearization economics, and suspension stabilization design. The combination of constant temperature, absence of frost heaving and other weather effects, and the existence of a uniform low pressure when the vehicle passes should permit far greater track stability than that obtained with a wheeled high-speed surface train. The MEL-system vehicle is assumed to attain a cruise speed of 270 m/s for calculating the economic potentiality of the system. The required track straightness for this speed is discussed This system should exhibit superiority over the air-transport system in air and sound pollution, conservation of energy resources fare economy, safety and reliability, potential passenger capability probable ultimate speed without sonic boom problems, and several other factors. The air-transport system is superior in capability of serving low-traffic-density areas and overseas routes, flexibility in circumventing equipment failures, and susceptibility to earthquakes. The major expense item for the operator of the MEL system is amort- ization of construction cost, but anticipated annual revenues for a New York, N. Y.-Los Angeles, Calif. route in the 1980's far exceed this cost. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ROMAG®transportation system

    Page(s): 617 - 620
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (407 KB)  

    The ROMAG®system of magnetically guiding and propelling vehicles using ordinary-temperature linear electric motors which combine levitation, thrust, guidance, and dynamic active suspension to achieve a high ratio of payload to vehicle weight is described. The vehicle requires low-cost passive track and provides a high degree of passenger ride comfort. It is applicable for low-cost low-speed "people-mover" vehicles as well as high-speed interurban transport systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A linear-induction-motor propulsion system for high-speed ground vehicles

    Page(s): 621 - 630
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2101 KB)  

    The design and development status of a linear-induction-motor propulsion system intended for use on high-speed ground vehicles is described. In this system, 3-phase, 60-Hz, 8250-V wayside power is converted by a solid-state power conditioning unit to a variable-voltage variable-frequency output suitable for use by linear-induction motors that provide up to 66 600-N (15 000-lb) propulsive thrust to the vehicle at 480 km/h (300 mi/h). The system provides continuously variable thrust during forward- and reverse-thrust modes, and such special features as automatic start-up, regenerative braking, and automatic failure/malfunction detection and shutdown. The system incorporates high-voltage water-cooled components for high specific thrust (more than 5 N/kgf, or 0.5 lbf thrust/lbf weight). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evaluation of fixed and moving primary linear induction motor systems

    Page(s): 631 - 637
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (581 KB)  

    Linear induction motors being proposed for high-speed ground transportation may have their primaries carried on board the vehicle or embedded in the guideway. This paper evaluates various aspects, such as power requirements, power switching and controls, utilization factor, efficiency and cost, etc., for these two alternatives and provides the basic format on which relative merits of various systems can be readily evaluated. The analysis shows that, in the fixed primary system, it is economically impractical to energize sections of the roadbed substantially longer than the vehicle. Even when the primaries in the roadbed are energized in sections of minimum length, the cost of the linear induction motor and additional switching and power network for the fixed primary system is an order of magnitude higher than that for the moving primary system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Propulsion and levitation forces in a single-sided linear induction motor for high-speed ground transportation

    Page(s): 638 - 644
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (707 KB)  

    A realistic mathematical model of the single-sided linear induction motor (SLIM) is presented. Using this model, propulsion and levitation forces are computed for a SLIM with back iron. The validity of the analysis is verified by tests on a laboratory model. Some associated problems are outlined, and the feasibility of SLIM's for high-speed ground transportation (HSGT) is discussed. With regard to HSGT, SLIM is compared with the double-sided linear induction motor. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • SYNCHROTRAC—An off-board control system for automated mass transit

    Page(s): 644 - 646
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB)  

    SYNCHROTRAC is a power control system that provides longitudinal control of vehicles by a unique method in which it distributes power to those vehicles. The vehicles are passive (control-wise) in that power modulation is accomplished by the vehicle's position within the traveling control section. Therefore, no on-board power modulation or communication equipment is required. The SYNCHROTRAC system can be readily employed in a wide variety of transportation applications. It is adaptable to the closed-circuit moving sidewalk applications that require slow captive vehicles operating with small headways as well as to the independently routable dual-mode application that requires fast vehicles operating with small headways. The specific vehicle design can vary to suit a particular application requiring only that the motive drive be an induction motor providing the appropriate vehicle dynamic response, i.e., voltage and frequency versus torque. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Principles of operation of linear induction devices

    Page(s): 647 - 656
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (584 KB)  

    An approach to the analysis of linear motors, based on the Fitzgerald superpotential is outlined. The usefulness of the approach is demonstrated in calculations of the fields, the streamline pattern, and the performance characteristics of some versions of the linear motor. Analysis of the streamline pattern brings out, in turn, the influence of the end effects. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design formulas for biquad active filters using three operational amplifiers

    Page(s): 662 - 663
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB)  

    A circuit configuration and its design formulas are presented for the realization of all the useful forms of a biquadratic voltage transfer function. The circuit employs three single-ended operational amplifiers, two capacitors, and at most eight resistors. With an additional resistor, it can realize any biquadratic voltage transfer function. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hilbert transform relations for products

    Page(s): 663 - 664
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (261 KB)  

    A general formula for the Hilbert transform of a product of complex-valued functions is developed. Certain simplifications are then exhibited for products often encountered in the context of modulation and signal processing. The approach chosen is one of frequency partitioning; this permits signal definition on complementary sections of the frequency axis and leads to compact and easily manipulated expressions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quotient generation with conventional binary multipliers

    Page(s): 664 - 665
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    With only minor modifications a conventional binary multiplier can generate the reciprocal of any given binary number to any desired precision. The quotient of any two binary numbers can then be generated as the product of the dividend and the reciprocal of the divisor. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Low-frequency noise of ion-implanted double-drift IMPATT diodes

    Page(s): 666 - 667
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (139 KB)  

    The low-frequency open circuit noise spectral density S(f) of an ion-implanted 60-GHz double-drift-region IMPATT diode was measured as a function of the dc avalanche current I0. Over an intermediate current range the noise follows an S(f)=a2VB02/I0relationship where VB0is the reverse breakdown voltage and a2≃4.5 × 10-20A/Hz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • A modified generalized discrete transform

    Page(s): 668 - 669
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    A modified version of the generalized discrete transform described earlier is now developed. The transform matrix of this modified version has a number of zeros as its elements, and consequently its matrix factors are more sparse. This results in fewer arithmetic operations and corresponding savings in computer time, when information is processed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The most highly-cited general interest journal in electrical engineering and computer science, the Proceedings is the best way to stay informed on an exemplary range of topics.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
H. Joel Trussell
North Carolina State University