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Sowing is one of the important operations in agriculture which requires accuracy, timeliness and skilled labour. Majority of Indian farmers still follow traditional manual method of sowing due to various reasons. Considering the requirement of farmers with small land holding and variety of crops grown it is required to develop a compact, and economical sowing machine. Literature survey, filed visits and data collection from stakeholders revealed the need for development of semi-automated sowing machine for major crops; Groundnut, Maize, Sunflower and Toor dal cultivated throughout the year, thus justifies the capital investment. Adopting the first principles of engineering design, a semi-automated sowing machine was designed, synthesized and fabricated. The machine consists of three subsystems; power system, traction system, seed metering system. The machine is walk-behind vehicle that can carry out sowing operation in three rows simultaneously. The developed sowing machine has been tested for its working and found to be satisfactory. The estimated reduction in cost of sowing is found to be in the range of 80–85% apart from reducing the time involved in sowing operation.

Since 2010, there has been a strong increase in passenger transport compared to the original forecast. This makes us think about possible ways to improve fixed electric traction installations performance that would enable to increase the transport capacity. To secure modern methods of operation, a quality railroad network with a quality and stable power supply system is necessary. If the existing DC traction system (3 kV) does not ensure sufficient power supply, some other acceptable way must be sought. The problem is technically solvable. If the lines capacity shall be used in the most efficient way, a systematic approach is necessary, in particular using multi-system locomotives with higher performance. Solving the issue of traction power systems development and modernization will be related with the conversion of DC traction system (3kV) into a uniform power supply system (25kV/50Hz).

Active stabilization of a constant power load (CPL) fed through an input LC filter fundamentally limits achievable performance of power control. This restriction is here explicitly shown to also apply to dynamic performance of so-called line current limitation, functionality regulated for traction systems by European standards. Subject to system stability, achievable control performance is explored, and is shown to roughly be reached with simple first-order low-pass filter controllers, added on top of basic stabilization. Depending on actual limitation realization and the available control inputs, it is shown that additional restrictions may apply. Derived results are verified through accurate non-linear simulations.

This paper discusses about a possibilities of compensation devices for traction support stations for Slovak Railways in the Slovak Republic. The first part of the paper describes power factor compensation and harmonic filtration. In particular, it deals with the possibility filtering 3rd and 5th harmonic. Next part showing a design of the compensation device based on the actual state of the power supply of the Slovak Republic Railway transformer stations. This proposal consists of a compensation device for the Cerveny Kut tunnel. This design contains a separate part, which is focused on harmonic filtering in particular 3rd and 5th harmonic and a separate part, which deals with the compensation of power factor. Subsequently, these proposals are merged for design a filter-compensating device for the support traction systems. The last part consists of the design of simple software, which allow calculating the individual parameters of the filter compensation device.

In locomotive traction system, unavoidable factors (such as idling and skidding) typically lead to the decline of traction performance of one or more motors, thereby resulting in the fluctuation of total torque traction amount. In this paper, the consensus-based total-amount cooperative tracking control (TACTC) is proposed to maintain the consensus of total torque traction amount with the given reference instruction. First, a disturbance observer is employed to estimate uncertain disturbances, then the output torque and observed values are fed back to design the total amount cooperative tracking control protocol, which is used to coordinate traction torque output redundancy of each individual motor. Simulation results show that the proposed approach is effective in reducing tracking time and tracking errors.

A strategy for the power division of a hybrid storage system for battery and UC based for electric vehicles using non-linear model predictive control (NMPC) is presented on this work. The system is modeled in a simple way and a cost function is proposed to minimize the battery current fluctuation and to preserve its health. Also, this function include the objective of regulating the UC voltage to a desired reference value. Simulation results are presented considering that the power required by the traction system is constant during the prediction horizon and are compared with the ideal case in which there is available future information of the power requirement.

In railway transport, braking and traction forces mainly depend on the normal force and the adhesion coefficient between the wheel and the rail. Regarding the restrictions on controlling the normal force, maximization of adhesion coefficient seems to be the only way of increasing braking and tractive efforts. Moreover, efficient utilization of adhesion can also reduce operating costs with avoiding early wheel and rail damages and minimizing the trip time. On the other hand, adhesion between the rail and the wheel is a highly dynamic function of many parameters such as environmental conditions, speed and slip ratio. Unfortunately, there is not any sufficiently accurate and reliable way of obtaining these parameters yet. Recently, an event based control scheme has been presented to maximize adhesion utilization without necessitating any of the above-mentioned parameters. This method provides efficient utilization of adhesion and eliminates problems (e.g. reliability, stability, continuous excitation of traction system and slow recuperation detection time) that are faced with the previously developed approaches. In this paper, dynamics of phase shift between the input and the output of the traction system is analyzed and an adaptive form of the recently proposed event based control scheme is constructed in order to further develop the adhesion utilization. Results obtained with the adaptive approach are compared with the conventional form of the control scheme as well as experimentally proven and industrially applied two successful methods for different driving scenarios and wheel-rail conditions. (C) 2018 Elsevier Ltd. All rights reserved.

A tool for holistic energy simulation and optimization of urban rail vehicles is presented. The modular vehicle model consists of easy to parameterize subsystems. All essential energy consuming subsystems (traction system and auxiliaries) can be considered via models of adequate detail level. Interaction between subsystems is simulated and driven by the operational conditions and internal controllers. Apart from energy signals the tool provides many other time signals, which contain valuable information for the vehicle manufacturer. Different workflow variants of the tool enable a case specific simulation or optimization. Furthermore a superordinated multi-objective mixed-integer optimization (MOMIO) can be applied to optimize the rail vehicle with respect to design parameters and operational conditions. Additionally a Brute-Force-Method (BFM) simulating all possible combinations enables to analyze the sensitivity of objectives (e.g. total energy) with respect to the selected design variables.

Current distribution in the electric traction system is an important factor regarding the electromagnetic influences on the surrounding metallic structures. The current value directly determines the magnetic field and consequently coupling of the systems. A single rail traction system can be equipped with return conductor. The return current flowing through return conductor has an opposite direction of supply current and decreases coupling and interferences. This paper presents the AC current distribution for both designs, with and without return conductor. Also, the soil resistivity is varied. The higher the soil resistivity, the higher is the amount of return current in rails and return conductor. The different construction of return conductor results in different impedance of return path. The relations of return conductor construction and return current value are analysed. Lightning can directly impact different traction system elements such as contact network, tower or return wire. The current distributions in several cases of lightning impacting different traction system elements are presented.

This paper presents a novel scheme of demagnetization monitoring and life extending control for traction systems driven by permanent magnet synchronous motors (PMSMs). Firstly, the offline training is carried to evaluate fatigue damage of insulated gate bipolar transistors (IGBTs) under different flux loss based on first-principle modeling. Then an optimal control law can be extracted by turning down the power distribution factor of the demagnetizing PMSM until all damages of IGBTs turn to balance. Next, the similarity-based empirical modeling is employed to online estimate remaining flux of PMSMs, which is used to update the power distribution factor by referring the optimal control law for the health-oriented autonomous control. The proposed strategy can be demonstrated by a case study of traction drive system coupled with dual-PMSMs. Compared with traditional control strategy, the results show that the novel scheme can not only guarantee traction performance but also extend remaining useful life (RUL) of the system after suffering demagnetization fault.

The inverter-motor drive system is the main traction force in electric vehicles (EVs). The overall efficiency of inverter-motor will directly determine the energy consumption of EVs. In this paper, aiming at improving the overall efficiency of inverter-motor, a novel methodology is proposed. Firstly, the iron loss, copper loss and stray loss of motor, as well as the devices’ conduction loss and switching loss in inverter are modeled. Afterwards, based on previous loss model strategy and gold section search strategy, a novel hybrid efficiency-optimization control strategy is proposed. The proposed method combines each benefit in loss-model and gold section search, and can realize high efficiency operation of the inverter-motor system in large power range. Additionally, the proposed method manifests faster search speed and better accuracy compared to conventional methods. Experiment results validated the effectiveness of the proposed hybrid control strategy. Meanwhile, the impact of the efficiency improvement on the driving cycle is further investigated through Advanced Vehicle Simulator (ADVISOR) simulations.

Due to the main traction force of electric vehicles (EVs), the overall efficiency of inverter-motor in traction system can seriously affect the energy consumption of EVs. In this paper, a novel hybrid methodology based on loss model and golden section search is proposed. Firstly, the iron loss, copper loss and stray loss of motor, combined with conduction loss and switching loss of inverter, are modeling. And the models of losses are validated by an experiment. Secondly, two efficiency improvement methodologies are investigated, namely loss model strategy and gold section search strategy. Then, a hybrid efficiency optimization control strategy is proposed based on losses model of the inverter-motor system and the two conventional methods, which yields a high efficiency operation point of inverter-motor system during different loads. Additionally, such novel methodology manifests faster search speed and more search accuracy than the conventional methods. Finally, an experiment results validates the effectiveness of the proposed hybrid control strategy.

A control strategy with four controllers is presented to overcome the dilemma of enhancing the robustness or decoupling for four-wheel-steering (4WS) vehicles with uncertainties and disturbances. Influences of steering system, uncertainties and disturbances on the traction system are attenuated by the first controller such that traction and steering systems are controlled separately. Robustness of the steering system is ensured by the second controller. Attenuating diagonal decoupling (ADD) is established by the remaining two controllers: coupling caused by uncertainties is rejected and diagonal decoupling is obtained. Simulations show that decoupling with better robustness is obtained.

The paper deals with a Dual Induction Motor control. A control strategy based on the Average Differential Control (ADC) is developed and adapted to work as an anti-slip control in a railway traction system. In addition to cancel the behaviour deviation between the motors supplied by a single inverter in case of an adhesion loss (or an unbalanced load), the proposed control strategy permits an action on the torque control to cancel the differential torque between the two motors. The control strategy is validated on a laboratory test bench with a Mechanical Railway Traction Load Emulator.

This paper deals with an embedded FDI-FTC approach applied on an over actuated electric’ vehicle. This method is described by three major steps: trajectory planning based on the inverse kinematic modeling of the vehicle, model base fault diagnosis of the traction system and vehicle control reconfiguration in faulty situations. Autonomous vehicles as that studied in this work are very suited to accomplish missions in confined space, or in hostile environments (in radioactive environment and spacial programs), where the success of the mission is more important than the cost of the over actuators. Co-Simulation results using experimental data shows the performances and advantages of the presented approach.

An innovative subway without supply rail is presented. This article deals with the sizing of the required on-board energy between two stations in the worst case. The influence of the mechanical limitations is studied: acceleration, jerk and torque limitations. These limitations have an impact on the total energy required and thus on the size of the on-bard energy storage element. These mechanical limitations must thus to be taken into account in the energy storage design.

Specially connected transformers such as V–V, Scott and Le-Blanc transformers are used to convert a three-phase supply into one or two single-phase supplies. These transformers are commonly used in the electro locomotive traction systems. This paper investigates the harmonic cancellation characteristics of such transformers. The results show that when two harmonic-producing loads are connected to each single-phase side of the transformers, the harmonics produced by the loads will cancel out at the primary sides of the transformers. The amount of cancellation is affected by transformer type and harmonic order. The study is performed for seven types of specially connected transformers.

This paper presents a novel mechatronic approach for the detection of wheel slip/slide and antislip control in railway traction systems, to enable an optimal use of adhesion in poor contact conditions. The proposed technique explores the variations in wheelset dynamic properties caused by condition changes at the wheel-rail contact and detects slip conditions from the torsional resonant vibrations of the wheelset axle indirectly. The modeling of a typical traction system, consisting of an induction traction motor (with associated power inverter and field-orientated control) connected to a wheelset via a gearbox, is introduced. The development of the slip detection and control scheme is presented, and the effectiveness of the proposed technique is demonstrated using computer simulations.

The benefits of substituting the conventional solid wheelset by independently rotating wheels (IRW) in actively steered trailed railway vehicles have already been presented in many works. If a traction system is included in this kind of vehicle it will interact strongly with the active steering system. This paper investigates how traction and active steering systems can be combined in an IRW bogie to produce a good curving performance. The combined steering and traction control concepts developed are implemented in simulation models and validated against a conventional passive vehicle.

Railway vehicles have principally been designed by mechanical engineers since railways began in the early 1800s, i.e. before electronics and feedback control were invented. Today however they contain substantial amounts of electronic and computer control, in particular the traction systems, which have been converted entirely. However electronic control can also be applied to the vehicle suspension and guidance functions, which can provide large improvements in performance. More significantly, incorporation of sensors, controllers and actuators into the design process from the start can enable vehicle designers to take advantage of different mechanical configurations which are not possible with a purely mechanical approach—in other words the true spirit of mechatronics. The paper reviews the concepts, the current state-of-the-art and opportunities for mechatronic developments for railways for the future.

In this paper a systematic approach is presented for extrapolating the lifetime due to bond wire lift-off in IGBT modules submitted to cyclic loading. Application profiles of the device are considered, as they are usually encountered in real current converters for railway traction systems. The proposed lifetime prediction scheme is based on the principle of the linear accumulation of the fatigue damage and takes into account the redundancy of the bond wires.

Hamilton-Russell traction has been used for many years in the pre-operativemanagement of patients with hip fracture despite a lack of evidence that it relieves pain. In order to evaluate the usefulness of this traction system, 303 patients with fractured neck of femur were randomly allocated to traction ( n =121) and no traction ( n =182) groups. Pain data were collected in the pre-operative period, and pressure sore data were collected in the pre- and post-operative periods. The groups were equivalent in all respects except mental function scores, where it was found that the no traction group had a disproportionate number of patients with very low scores. Analysis of covariance (ANCOVA), which offers the possibility of posthoc statistical control when group equivalence has not been obtained, was used to test for differences in outcome measures. Analysis of the pressure sore data found no difference in global scores between thetraction and no traction groups. Analysis of a small number of specific sites found that patients in traction were less likely to incur pressure damage to the heel on the opposite side to the injury ( P =0.016). During data collection, patients were asked to describe the pain they felt when they were at rest, and when they attempted to move about the bed. On analysis of the data, no difference was found between the traction and no traction groups in pain experienced on movement. However, it was found that patients in the traction group experienced less pain at rest on the day after the injury than those in the no traction group ( P =0.002). Consequently, we recommend that Hamilton-Russell traction should not beroutinely used in the pre-operative treatment of hip fracture patients. However, there is a case for retaining its use in the minority of patients who are unable to receive definitive surgical treatment within 24 hours of the injury.

This study aims at improving vehicle maneuverability of global turning motions including critical turning, by an integrated control strategy which coordinates steering and traction systems. The vehicle model expressing global turning motions has nonlinear dynamics, and this makes it impossible to apply the linear control theory directly. In this paper, the nonlinear vehicle model which also includes transient characteristics of tires is linearized by a nonlinear transformation, and μ synthesis is applied lo the linear model. As a result, the integrated control strategy which compensates robust stability against perturbations generated under various driving environments is obtained.

In this paper the main features of an on-line expert system, still under developement, for online diagnosis and control of a railway locomotive is described, with particular reference to the system architecture and the knowledge representation aspects. The system's behavior during operation is illustrated by an example.

Summary A case of Pierre Robin Anomaly with severe, prolonged respiratory distress and feeding difficulties is presented. The respiratory distress is adequately relieved by mandibular forward traction. The procedure employing a mandibular suspension and elastic traction system is described. Feeding under the traction was successful, providing more effective self-control of the tongue. The authors recommend the mandibular traction device described here as a very simple life-saving approach to the problems in the Pierre Robin Anomaly.

The Adatomed PC IOL-CH has two semicircular loops which make a circular haptic that is equally flexible in all directions. It gives a full 360° distension of the capsular bag equator and secures a close contact between the optic and the posterior capsule without wrinkles. Each of the two semicircular loops has a two-point attachment to the optic. Such four-point fixation of the haptic results in a stable connection between the optic and the haptic and thereby also to the capsular bag. By means of a thread traction system, the loop ends are pulled in pairs onto the posterior or anterior surface of the optic close to the attachments of the opposite loop, reducing the size of the whole implant to a width approximately that of the diameter of the optic (7 mm) and a length of 9-10 mm. The thread is pulled through a thin elastomere membrane functioning as a friction lock on the anterior surface of the optic, preventing the haptic from unfolding. The folded, small intraocular lens (IOL) is inserted into the capsular bag with minimal trauma to the tissues, but is still big enough not to be floating around in the capsular bag without control. The correct position can be verified before the haptic is allowed to unfold and expand inside the bag by cutting the thread. The thread with the friction lock is removed by pulling the long suture ends hanging out of the corneal wound. The main advantages of such an IOL are presented herein.

In this study eight macerated, human child skulls (dental age approximately 9.5 years) were subjected to a standardized high-pull headgear traction system. Tensile forces from 0.5 to 3.5 N (1 N = 0.1 kgf) per side were produced to the maxillae. Displacements of skeletal components were determined at 22 indicator points per skull by means of laser holography. Coordinated displacements and variations in amount and direction were established in all skulls. The overall amount of displacements was primarily a characteristic of an individual skull, not of a particular displacement. On the average, the maxillae were displaced in a slightly downward and posterior direction almost parallel to the occlusal plane. No deformations of skeletal components were seen. Results indicated that initial displacements of the maxillae and other skeletal components are not in the same direction as the direction of applied forces.