Dalian University of Technology

Kun Wang

Yanquan Zou

Shaopeng Zhong

Haimin Jun

Xiaodong Wang

Siying Ling

Liding Wang

Lu Zhang

Kai Liu

Kangli Zhu

Quanzhi Wang

Tianli Tang

Baodi Yu

A method for estimating road travel time based on the built environment and low-frequency floating car data belongs to the technical field of urban traffic management and traffic system evaluation. The method takes built environment as an explanatory variable of the road travel time. The interpretability of this variable is proved by a numerical example. In addition, the method determines distribution parameters of road travel time using the number distribution of vehicles instead of distance. The benefits of the method are that: (1) it explains the positive effect of built environment on road travel time; and (2) it reflects the speed difference among different road sections, which can improve the precision of estimating road travel time.

Method for estimating road travel time based on built environment and low-frequency floating car data

The present invention relates to a method for estimating distribution of urban road travel time in considering operation state of taxi, and belongs to the technical field of urban transportation planning and management. The distributions of path travel time are respectively estimated according to different operation states of the taxi. When the distribution of the path travel time is estimated, adjacent road sections in the road network are not independent. In the present invention, the Markov model is added to describe the correlation of the travel time distribution between the adjacent road sections, so as to increase science and accuracy of the estimation result. In the present invention, the weight is set according to the proportion of the number of the vehicles under two different operation states to obtain the final distribution of the path travel time. Driving behaviors of taxi drivers under two operation states of no passenger and passenger service may be different, so a difference between the travel time estimated from direct use of taxi data and a true value inevitably exists. The proposed model is calculated through Shenzhen data, which shows that the calculated travel time distribution function is more accurate after considering the operation states.

Method for estimating distribution of urban road travel time in considering operation state of taxi

The precision lapping and polishing device for external cylindrical surface of disk part and its taper error adjustment method. The device composes a circular baseplate, slant rails, baffles, pressure plates, copper blocks, a washer blanket; blanket plates, a set of bead shafting, a friction driving wheel, a DC motor, a mobile power supply, a LED lamp and a cover body. By adopting the working principle that the generatrix rotates around the fixed axis to form the cylindrical surface, the ultra-precision machining of the cylindrical surface of disk part is realized. The radial-continuous-automatic-micro feeding of the disk part is realized by thinning the thickness of the circular baseplate which is internally tangent to the generatrix of the circular baseplate during the process of lapping and polishing. The device has the advantages of operating simply, adjusting conveniently, low cost and is of important value for popularization and application.

Precision lapping and polishing device for external cylindrical surface of the disk part and its taper error adjustment method thereof

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Dalian, China

Kun Wang