Coordinating on-ramp queue control with adjacent local signal controller: an algorithm to assist ramp metering application
This paper describes a queue control algorithm which is able to coordinate its operation with that of an adjacent local signal control so that its efficiency is improved. A microscopic simulation model (AIMSUN) was used to test the operation of the new queue control algorithm and compare its performance with that of the standard queue control. The assessment has shown the new algorithm to be a significant improvement in reducing the variation of the release rate and the frequency of exceeding the storage capacity whilst the efficiency of utilising ramp space increased. Also, the new algorithm was found to be less sensitive to changes in ramp demand and some parameter settings originally found critical to the operation of standard queue control. For the covering abstract see ITRD E134653.
ALINEA Local Ramp Metering: Summary of Field Results
Asservissement Linéaire d'Entrée Autoroutière (ALINEA), a local feedback ramp-metering strategy, has had multiple field applications, and more applications are planned in several European countries. The main features of ALINEA are presented and the field results achieved to date at both single and multiple ramps of the Boulevard Périphérique in Paris and at the A10 West motorway in Amsterdam are summarized. The reported results indicate easy application, flexibility, and high efficiency of ALINEA. Planned implementations are outlined.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.