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The traction cable is paralleled with the existing traction network of electrified railway through transverse connecting line to form the scheme of long distance power supply for the traction network. This paper aims to study the scheme composition and power supply distance (PSD) of the scheme.

Based on the structure of parallel traction network (referred to as “cable traction network (CTN)”), the power supply modes (PSMs) are divided into cable + direct PSM and cable + autotransformer (AT) PSM (including Japanese mode, French mode and new mode). Taking cable + Japanese AT PSM as an example, the scheme of long distance power supply for CTN under the PSMs of co-phase and out-of-phase power supply are designed. On the basis of establishing the equivalent circuit model and the chain circuit model of CTN, taking the train working voltage as the constraint condition, and based on the power flow calculation of multiple train loads, the calculation formula and process for determining the PSD of CTN are given. The impedance and PSD of CTN under the cable + AT PSM are simulated and analyzed, and a certain line is taken as an example to compare the scheme design.

Results show that the equivalent impedance of CTN under the cable + AT PSM is smaller, and the PSD is about 2.5 times of that under the AT PSM, which can effectively increase the PSD and the flexibility of external power supply location.

The research content can effectively improve the PSD of traction power supply system and has important reference value for the engineering application of the scheme.

Explains how the Tracminer project aimed to provide a robust, low cost device to be mounted as an accessory on the motorized wheels of traction machines, in order to increase grip on loose soils. The main goal was to provide a device increasing by 30‐40 per cent the traction capacity of the given machine in soft or marshy soil working conditions. The intended device was designed to be robust and simple to adapt to existing machines. A key element of the development strategy was to provide an accessory easy to mount on the machine, which can remain “idle” (in this case, retracted) while not needed. The machine may then be operated as usual, with the opportunity to engage the accessory in action when a better ground grip is required. Such a possibility offers significant advantages for the Tracminer accessory when compared with other permanent traction enhancement solutions such as metallic frames with grids attached to the wheels, accessory caterpillars, etc.

In large equipment and highly complex confined workspaces, the maintenance is usually carried out by snake-arm robots with equal cross-sections. However, the equal cross-sectional design results in the snake arm suffering from stress concentration and restricted working space. The purpose of this paper is to design a variable cross-section elephant trunk robot (ETR) that can address these shortcomings through bionic principles.

This paper proposes a cable-driven ETR to explore the advantages and inspiration of variable cross-section features for hyper-redundant robot design. For the kinematic characteristics, the influence of the variable cross-section design on the maximum joint angle of the ETR is analysed using the control variables method and the structural parameters are selected. Based on the biological inspiration of the whole elephant trunk following the movement of the trunk tip, a trajectory-tracking algorithm is designed to solve the inverse kinematics of the ETR.

Simulation and test results show the unique advantages of the proposed variable cross-section ETR in kinematics and forces, which can reduce stress concentrations and increase the flexibility of movement.

This paper presents a design method for a variable cross-section ETR for confined working spaces, analyses the kinematic characteristics and develops a targeted trajectory control algorithm.

In a helicopter rotor comprising a propulsion unit mounted at the tip of each blade, each unit including rotating masses subject to gyroscopic reaction forces tending to alter the attitude of the propulsion unit, means are provided for applying a force to the unit in opposition to the gyroscopic forces, the magnitude of the opposition force being varied in accordance with changes in the rotative speed of the rotating masses. The invention is described for a two‐bladed rotor wherein each blade 14 which is mounted for conventional pitch‐changing and flapping movements, comprises a spar 13 formed at its tip with a yoke 21 which supports a gas‐turbine engine 19. The engine carries rearwardly extending arms 32 which terminate in brackets 33 forming pivots for a control surface 31 located in the stream for propulsion gases from nozzle 26. The surface 31 has an arm 34 connected by a link 35 to a power element 36 which is controlled by an engine fuel control unit 37 adjusted by the pilot through a linkage 39 to vary the fuel supplied to the engine (and thereby the engine speed) from a fuel line 38. The rotating compressor and turbine of the engine exert gyroscopic forces which apply a positive pitching moment to the engine and this is counter‐acted by increasing the incidence of surface 31 with an increase in fuel supply where the surface, through arms 32, applies an opposing negative pitching moment to the engine. The adjustment of the surface may be made responsive directly to the speed of rotation of the engine or to twisting stresses applied to the spar 13.

The swivel construction method is a specially designed process used to build bridges that cross rivers, valleys, railroads and other obstacles. To carry out this construction method safely, real-time monitoring of the bridge rotation process is required to ensure a smooth swivel operation without collisions. However, the traditional means of monitoring using Electronic Total Station tools cannot realize real-time monitoring, and monitoring using motion sensors or GPS is cumbersome to use.

This study proposes a monitoring method based on a series of computer vision (CV) technologies, which can monitor the rotation angle, velocity and inclination angle of the swivel construction in real-time. First, three proposed CV algorithms was developed in a laboratory environment. The experimental tests were carried out on a bridge scale model to select the outperformed algorithms for rotation, velocity and inclination monitor, respectively, as the final monitoring method in proposed method. Then, the selected method was implemented to monitor an actual bridge during its swivel construction to verify the applicability.

In the laboratory study, the monitoring data measured with the selected monitoring algorithms was compared with those measured by an Electronic Total Station and the errors in terms of rotation angle, velocity and inclination angle, were 0.040%, 0.040%, and −0.454%, respectively, thus validating the accuracy of the proposed method. In the pilot actual application, the method was shown to be feasible in a real construction application.

In a well-controlled laboratory the optimal algorithms for bridge swivel construction are identified and in an actual project the proposed method is verified. The proposed CV method is complementary to the use of Electronic Total Station tools, motion sensors, and GPS for safety monitoring of swivel construction of bridges. It also contributes to being a possible approach without data-driven model training. Its principal advantages are that it both provides real-time monitoring and is easy to deploy in real construction applications.

The application of the sliding mode control has two obstacle phenomena: chattering and high activity of control action. The purpose of this paper concerns a novel super-twisting adaptive sliding mode control law of a human-driven knee joint orthosis. The proposed control approach consists of using dynamically adapted control gains that ensure the establishment, in a finite time, of a real second-order sliding mode. The efficiency of the controller is evaluated using an experimental set-up.

This study presents the synthesis of a robust super-twisting adaptive controller for the control of a lower limb–orthosis system. The developed control strategy will take into consideration the nonlinearities as well as the uncertainties resulting from the dynamics of the lower limb–orthosis system. It must also guarantee a good follow-up of the reference trajectory.

The authors first evaluated on a valid subject, the performances of this controller which were studied and compared to several criteria. The obtained results show that the controller using the Adaptive Super-Twisting algorithm is the one that guarantees the best performance. Validation tests involved a subject and included robustness tests against external disturbances and co-contractions of antagonistic muscles.

The main contribution of this paper is in developing the adaptation super-twisting methodology for finding the control gain resulting in the minimization of the chattering effect.

This study proposes a tensegrity-based traction structure with D-bar dual cable units. It is used to connect the airship and the ground to stabilize the airship.

The mathematical models and dynamic models of the D-bar dual cable (hereafter referred to as DD cable) unit of the tensegrity-based traction structure are established. Based on the minimum mass method, the mass of the DD cable unit in the critical state (cable member is yielding, or bar member is buckling or yielding) is analyzed. Then, the tensile strength of the DD cable unit and single cable unit under the same condition is compared using the control variate method. Finally, based on ANSYS dynamic simulation, the stability of the two structures under the same external force disturbance was tested.

Expressions for the minimum mass of the DD cable unit under different failure conditions are solved. Dynamic simulation results show that the capacity of resisting disturbance of the DD cable unit is much better than that of the single cable unit under the same wind speed. So, we find a structure more suitable for the fixed connection of an airship.

This study helps to provide theoretical reference and thinking for the practical application of the traction structure with a D-bar dual cable unit.

Stray currents in the ground are those which have their origin in electrical power and traction systems, as distinct from currents of voltaic origin. The electrical industry is concerned with the control of such stray currents, partly because of its awareness of responsibility towards the authorities operating other underground services, and partly because of its own very large capital investment in underground cables, for which even a low incidence of corrosion would represent a serious economic and operational drawback. The following article is a brief review of the existing techniques for the survey and control of stray current corrosion, cathodic protection being an important method of control.

Several studies have aimed to develop robotic systems which move in transmission lines. Until this moment, all of them have a high weight and cost associated with the equipment and reduced battery autonomy time. In this context, this paper aims to propose the POLIBOT (POwer Lines Inspection roBOT) with low cost and weight, enabling the movement over the lines and an easier installation and remove.

The designed robot uses the Profiles Manufacturing Methodology (PMM). The construction of the robot mechanical structure uses modularized aluminum parts built through square profiles. Thus, it’s possible a drastic reduction in production time as well as cost reduction and weight when comparing this method with other manufacturing processes like foundry, for example. For hardware and software systems, the use of free and open source software causes a significant reduction in cost and project execution time. The benefits of using open source systems are immeasurable, both from academic and industrial applications.

The POLIBOT platform is one solution to the problem of inspection in power lines. With this robot, more lines are maintained with lower time. In its constructive aspect, the robotic mechanism is designed using principles of bioengineering. The use of this principle was successful, considering that obstacle transposition is performed with stability and low energy consumption.

The suggestion for future researches is to replace the battery for solar energy and construction in polymeric material to avoid high magnetic fields.

The commercial application is evident because manual inspections are inefficient, very expensive and dangerous. Thus, it is growing the number of researches that develop mechatronics systems for this kind of inspection.

The impact is the reduction of accidents because the present procedure requires precision of movements, where the pilot and electrical technician are close to high electrical and magnetic fields. In addition, for some tasks, the worker has to walk on the line to reach some important points. Thus, those tasks involve high risk of death.

The PMM methodology represents an innovation to the state of the art because others robotic mechanisms proposed for inspection tasks present total structure mass between 50 and 100 kg and POLIBOT has only 9 kg. Other fact is its price for implementation as this robot used the robot operating system (ROS) framework, what dispense the use of licenses. Other important features are that the robot performs the tasks autonomously, which reduces errors introduced by the operator and its low manufacturing cost as compared with other projects.

The purpose of this paper is to determine the external magnetic field density of the traction transformer for EMU and to find the model for its computation.

The magnetic flux density in the surrounding region of the traction transformer was modeled and calculated using FEM. The transformer was modeled in a way that tank, clamps and current sources were taken into account. Most frequent operating modes for the basic 50 Hz current harmonic, and most represented higher harmonic of 1,950 Hz loading current, were analyzed.

Matching calculated and measured values were obtained on the finished transformer. The developed calculation has proved to be a useful tool for the stray field calculation outside this type of transformer. Calculated values of the flux density are lower then the maximum permitted values defined by the DIN VDE 0848 standard.

This paper presents a study of calculation compared to measurement of magnetic field density outside an oil immersed transformer.