Suboptimal feedback control of a string of vehicles moving in a single guideway

Trunspn Res. Vol. 6, pp. i-vi. Pcrgamoo F+ress1972. printed in Great Britain

TRANSLATED

ABSTRACTS OF PAPERS

W. L. GARRARD,GORY

R. HAND and ROBERTRAEMER:Sn&optimolf&hack control of a string of vehicles nwving in a single g&&way. Transpn Res. 6, X97-210. An e5icicot method for suboptimal feedback control of spacing and velocity errors within a string of vehicles is preaented. The s&optimal control is considerably less complex than the optimal and appoazs well adapted to the control of a lm number of v&i&s. Hybrid simulatioo indicates that the performance of the suboptimal system compares favorably witb the +rformance of the optimal system. ROBERTCROWand JUANLONOBOT:A fwecasti~ model of the market for new aircrqft: the case of the Concorde. Transpn Res. 6, 21 l-224. This paper prsleats a method for far#msting the demand for travel oo a new aircraft and translating that demand into foecasts of the aircraft’s Drofitabilitv and the number that cau be u&cted to be sold. Dl@rent assumptions con&&g fare-structure, the aircraft’s w capacity and its load factors are employed to intesti@e its market under a number of diifezettt circumstances. Tbc travel demand _model employed is an extension of the “abstract mode” approsch. Its forecasting propcrtvs are apparently much better than previous versions. The entlrc model of the a&raft market is a set of no&near simultaneous equations in which simultan&y botwecn airline supply policies and passcnscr rcqomcs to relative departure frcquea&s are particularly important. Tentative cosdurions about the Concorde itself arc that it may have much more appeal to lloI)-IIlxury travdlers than is cummonl y be!ievod and.* thft its relatiyely amall Fm ~~~tiw;~ help to ensure its survival m compettium wh the Urnted States SST or

MARTINJ. BECKMANN and KAILASHC. KAPUR: Dnulity and tmnspertatkm analysis. Ttmtspn Res. 6, 225-236. ThBcon@ptsofdemandandaupplyfuncticmsisveryexae&alfor trinrportation analysis, plauningandde&n. Basedon~functions,theconceptrofnctn43cialben&tsfroma trtmsportation m are develop& which consider Mibk demand. For the comt&md optimi22ltion problem of ma&C&an of net ba@ts suL&ct to v8rious ccmon the systsmpuruastnrs,vrriousduatitg~areobtamedbsscd~psntrald~itytheorconsIn non-linear prolpumming. The dual in many cases gives various economic interpretations and is computationally efEcient. EARLW. ADAMS,JR. and MMXMZ. H. Srao: Timing churacteristics of urban mess transit construction econometric amly&t of the BARTD system. Transpn Res. 6,237~243. This is a study of the lag structure inherent in the umstructioo of urban mass transit systems. The hypothesis is that the constructioo time of componants in a mass transit system can be expla+d by the ocale, the tcchnolo#al characteristics of the class of projects to which a contract bclonoe and its complexity. Variants of the hypothesis 85~ tested a&nst data from the Ray Area Rapid Transit District (BARTD). The r&or &dings are that a stable relationship exists betwscn 6011struction time, the technological cbamcteristice of the project and its cost which is usud as a proxy for scale. The complexity variable did not have conlciutent explanMry power. Furthermore, the anah+ suw that for umall zrr&cts the tcchnolo~ &aracMstica areafarmoAimport&dct&in8ntof Cxmstr&~on-timc thao scale. The study coool& with a d&us&n of the imolications of the 5ndintc? for Dublic policy, that &, with the potential use of expenditures 0; urban mass transit as & in&-t of economic stabilization. i