A novel method for determining fixed running time in operating electric train tracking optimal speed profile

<span lang="EN-US">Tracking the optimal speed profile in electric train operation has been proposed as a potential solution for reducing energy consumption in electric train operation, at no cost to improve infrastructure of existing Metro lines as well. However, the optimal speed profile needs to meet fixed running time. Therefore, this paper focuses on a new method for determining the fixed running time complied with the scheduled timetable when trains track the optimal speed profile. The novel method to ensure the fixed running time is the numerical-analytical one. Calculating accelerating time ta, coasting time tc, braking time tb via values of holding speed vh, braking speed vb of optimal speed profile with the constraint condition: the running time equal to the demand time. The other hands, vh and vb are determined by solving nonlinear equations with constraint conditions. Additionally, changing running time suit for each operation stage of metro lines or lines starting to conduct schedules by the numerical-analytical method is quite easy. Simulation results obtained for two scenarios with data collected from electrified trains of Cat Linh-Ha Dong metro line, Vietnam show that running time complied with scheduled timetables, energy saving by tracking optimal speed profile for the entire route is up to 8.7%, if the running time is one second longer than original time, energy saving is about 11.96%.</span>

Optimization Technique for Reducing Energy Consumption of Rapid Transit Mode

Since the time, our mother earth was created, energy was taken from the universe(System),now energy is being depleted as non-renewable source. Energy can neither be created nor be destroyed as it transforms in one form to another. So researchers came up with renewable source of energy as the solution like solar, wind and tidal waves. The world is experiencing an energy crisis and the prices of petroleum products like petrol and diesel has gone up. So its time to come forward and save the future of our mother earth. The paper deals in reducing energy consumption of rail rapid transit mode i.e. of metro. It shows how driving behaviour can be controlled using optimized speed profile and efficiency can be managed. It states round trip data taken of Mumbai(India) metro from Versova to Ghatkopar and viceversa. Speed data was taken from GPS(Global Postioning System) embedded in Smart watch Software. Time interval was noted and distance, acceleration data was formulated using Newtons Equations of Motion. Energy Consumed was drawn out from tractive effort data. Then efficiency, energy lost and regenerative braking energy was calculated using Work Energy Theorem. Maximum efficiency of 88.27% was obtained between Asalpha to Jagruti Nagar Station while between Western Express Highway to Andheri Station a 72.66% efficiency was analysed. This affects the time interval of metro trains arriving at station, also the amount of boarding and alighting passengers from the train. A model was designed and simulated using results obtained. The paper also deals with the prototype of Regenerative energy which can either be used in braking systems but also for acceleration and cruising purpose. The idea can benefit a developing country like India where 6.3% GDP is from Transportation Industry. Keywords: optimized speed profile, efficiency, regenerative braking energy

Rollover Prevention Control for Autonomous Electric Road Sweeper

This paper presents a method to prevent the rollover of autonomous electric road sweepers (AERS). AERS have an articulated frame steering (AFS) mechanism. Moreover, the heights of the center of gravity of the front and rear bodies are high. As such, they are prone to rolling over at low speeds and at small articulation angles. A bicycle model with a nonlinear tire model was used as a vehicle model for AERS. Using that vehicle model, path tracking and speed controllers were designed in order to follow a predefined path and speed profile, respectively. To check the rollover propensity of AERS, load transfer ratio (LTR) based the rollover analysis was completed. Based on the results of the analysis, a rollover prevention scheme was proposed. To validate the proposed scheme, a simulation was conducted using a U-shaped path under constant speed conditions. From the simulation, it was shown that the proposed scheme is effective in preventing AERS from rolling over.

Energy Efficiency and Smooth Running of a Train on the Route While Approaching Another Train

This paper presents an innovative technique of traffic management on a route divided into fixed block distances for trains equipped with a continuous area data transmission system that ensures information exchange between a train and a control center. The originality of the technique is focused on the optimization of the following train’s speed profile in terms of energy consumption under the need to maintain a minimum distance to the preceding train and to assume the smooth running of the following train, using elements of fixed and mobile block distance methods. The obtained results are an answer to the question of whether it is possible to obtain a smoother movement of the train and savings in mechanical energy consumption if the speed profile of this train is adjusted to the conditions before the train, such as information about the speed of the preceding train.

Ocean Front Reconstruction Method Based on K-Means Algorithm Iterative Hierarchical Clustering Sound Speed Profile

As one of the most common mesoscale phenomena in the ocean, the ocean front is defined as a narrow transition zone between two water masses with obviously different properties. In this study, we proposed an ocean front reconstruction method based on the K-means algorithm iterative hierarchical clustering sound speed profile (SSP). This method constructed the frontal zone from the perspective of SSP. Meanwhile, considering that acoustic ray tracing is a very sensitive tool for detecting the location of ocean fronts because of the strong dependence of the transmission loss (TL) on SSP structure, this paper verified the feasibility of the method from the perspective of the TL calculation. Compared with other existing methods, this method has the key step of iterative hierarchical clustering according to the accuracy of clustering results. The results of iterative hierarchical clustering of the SSP can reconstruct the ocean front. Using this method, we reconstructed the ocean front in the Gulf Stream-related sea area and obtained the three-dimensional structure of the Gulf Stream front (GSF). The three-dimensional structure was divided into seven layers in the depth range of 0–1000 m. Iterative hierarchical clustering SSP by K-means algorithm provides a new method for judging the frontal zone and reconstructing the geometric model of the ocean front in different depth ranges.