Mobile Transportation Systems Research Articles

4 × 4 MIMO Fiber-Wireless System with RoF Transmission Capability

Transport networks, particularly fronthaul systems are facing substantial issues as a result of the expansion of radio access technologies (RATs) in 5G and beyond networks. Due to the difficulties and high expense of installing fiber links, a traditional fiber-optic based mobile transport system will not be adequate for delivering radio signals to new antenna sites. The ease and speed of installation make wireless transport systems an appealing alternative. In this work, a 4×4 MIMO fiber wireless system with wavelength division multiplexing (WDM) and polarisation division multiplexing (PDM) radio over fiber (RoF) transmission capacity is proposed and Simulated. Moreover, a Filter Bank Multicarrier modulation is employed to increase the system capacity. In order to improve the spectral efficiency of RoF and fiber-wireless systems, FBMC is an excellent choice for modulation. Also a 4×4 MIMO OQAM based FBMC signal is simulated and its performance is compared with 2 × 2 MIMO system. Satisfactory performance is confirmed with quality factor of 14.6040 and minimum BER of 1.22×10-45. 4 × 4 MIMO fiber wireless system achieved better quality factor compared to 2×2 MIMO system. Simulation of both systems are performed using Matlab integrated with Optisystem Software. It offers an affordable solution to enable massive amount of MIMO signal transmission and may be a potential approach for upcoming mobile access and radio transport networks in high frequency bands.

Adaptive Transmission for Unmanned Mobile System

The unmanned mobile system of any transport facilities (land, space and underwater) should have high extent of reliability and non-failure operation in process. The elementary mechanical system in a combination to the elementary control system can provide these qualities. Besides the unmanned mobile system of space and underwater transport should have small sizes and weight and self-regulation possibility at origination of non-staff situations. Automatic gearboxes existing now (CVT) are the most complicated mechanical systems and have the most complicated hydro mechanical control system [1]. Such transmissions are absolutely unsuitable for unmanned mobile system because of their low reliability and inadequacy to a changing circumambient.
 Recently adaptive gear variators are developed [2, 3, 4, 5]. The adaptive variator represents the self-controlled gear planetary train with the constant engagement of the toothed wheels. Who’s that was created on the basis of an author's disclosure «Effect of force adaptation in mechanics». The adaptive gear box of the automobile represents a brand-new planetary gear variator in the form of two mobile kinematic chain with the elementary additional original constraints. The adaptive variator has ability to drive the executive tool with a speed which is back - proportional external loading at constant power of an engine. The basic advantages of an adaptive gear variator: absence of the control system, simplicity of a design, full adequacy to working conditions. It seems expedient to use an adaptive gear variator in the transmission of a mobile transport system.
 Adaptive drivetrain based on usage of a gear variator (theoretical bases, tests, characteristics and practical recommendations) is in-process presented.

Plant and Controller Optimization for Power and Energy Systems With Model Predictive Control

Abstract This article explores the optimization of plant characteristics and controller parameters for electrified mobility. Electrification of mobile transportation systems, such as automobiles and aircraft, presents the ability to improve key performance metrics such as efficiency and cost. However, the strong bidirectional coupling between electrical and thermal dynamics within new components creates integration challenges, increasing component degradation, and reducing performance. Diminishing these issues requires novel plant designs and control strategies. The electrified mobility literature provides prior studies on plant and controller optimization, known as control co-design (CCD). A void within these studies is the lack of model predictive control (MPC), recognized to manage multi-domain dynamics for electrified systems, within CCD frameworks. This article addresses this through three contributions. First, a thermo-electromechanical hybrid electric vehicle (HEV) powertrain model is developed that is suitable for both plant optimization and MPC. Second, simultaneous plant and controller optimization is performed for this multi-domain system. Third, MPC is integrated within a CCD framework using the candidate HEV powertrain model. Results indicate that optimizing both the plant and MPC parameters simultaneously can reduce physical component sizes by over 60% and key performance metric errors by over 50%.

Qualitative Analysis of the Dynamics of a Trailed Wheeled Vehicle with Periodic Excitation

This article examines the dynamics of the movement of a wheeled vehicle consisting of two links (trolleys). The trolleys are articulated by a frame. One wheel pair is fixed on each link. Periodic excitation is created in the system due to the movement of a pair of masses along the axis of the first trolley. The center of mass of the second link coincides with the geometric center of the wheelset. The center of mass of the first link can be shifted along the axis relative to the geometric center of the wheelset. The movement of point masses does not change the center of mass of the trolley itself. Based on the joint solution of the Lagrange equations of motion with undetermined multipliers and time derivatives of nonholonomic coupling equations, a reduced system of differential equations is obtained, which is generally nonautonomous. A qualitative analysis of the dynamics of the system is carried out in the absence of periodic excitation and in the presence of periodic excitation. The article proves the boundedness of the solutions of the system under study, which gives the boundedness of the linear and angular velocities of the driving link of the articulated wheeled vehicle. Based on the numerical solution of the equations of motion, graphs of the desired mechanical parameters and the trajectory of motion are constructed. In the case of an unbiased center of mass, the solutions of the system can be periodic, quasi-periodic and asymptotic. In the case of a displaced center of mass, the system has asymptotic dynamics and the mobile transport system goes into rectilinear uniform motion.

Modular growth and function in the vascular cryptogam Lycopodium annotinum

Lycopodium annotinum L. is a long-lived plant that consists of a series of annually produced segments, which can be aged; a 20-year life cycle can be synthesized from historical records of the plant’s past growth. Detailed analyses of the modular construction of the plant show elements of deterministic and opportunistic growth which provide a framework in which physiological processes can be interpreted. A balance between deterministic and opportunistic growth is achieved by the relationships in terms of structure, function and longevity, between a series of horizontally growing modules and a series of more ephemeral vertically oriented modules. Each annual horizontal segment has an increasing probability of mortality as it ages, yet the segments are organized into units with indefinite apical growth and proximal senescence. In contrast, each vertical module has the inverse relationship between age and the probability of mortality : the youngest segments always die first. The result is a plant with fixed structures for photosynthesis, spore production and nutrient and water uptake, but with a highly organized and mobile transport system.

Man-Made Noise in Urban Environments and Transportation Systems: Models and Measurements

Analytically tractable statistical-physical models of manmade noise environments have been constructed [1]-[3]. These permit quantitative description of the various types of electromagnetic interference appearing in typical radio receivers and, in particular here, for the communication links employed in mobile transportation systems and urban environments generally. This paper presents a summary of some of the principal analytical results obtained to date [1], [4], and includes some suggested next steps for joint theoretical and experimental study of these increasingly important phenomena. Firstorder probability density functions (pdf's) and probability distributions (pd's) are obtained explicitly; (higher order pdf's and pd's may also be found by similar methods) [2]. These models are based on a Poisson distribution of sources in space. The approach is canonical, in that the results are, in form, independent of particular emitted waveforms, propagation conditions, source distributions, beam patterns, and specific system parameters, as long as the interference is narrow-band following (at least) the aperture and/or the RF stages of a typical receiver. Considered here only are the cases of communication interference, where source and receiver bandwidths are comparable. The paper concludes with a short discussion of some features of suggested future interaction between theory and experiment.