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Recent classifications of resistance training methods classify them in gravitational, to move the resistance we will have to apply an acceleration greater than the force of the gravity (9.81 m·s−1), and non-gravitational methods that allow us to work in multiple directions, not being exclusively conditioned by gravity. Bodyweights training, also known as calisthenic exercise; Free-weights training, weight lifting through barbells, dumbbells, and kettlebells; inertial devices, how flywheel devices that an active stretch, while trying to brake an external resistance that exceeds the capacity of the muscle; and external resistance variable resistance, where resistance varies throughout range of motion are, among others, the main methods of resistance training currently. In this chapter, a contextualization of them will be carried out, exposing those essential aspects that it is necessary to know from a practical application and allowing the reader to understand the following chapters where each of them will be addressed in depth.

The applied physics that explains the nature of flywheel resistance training devices highlights the importance of knowing the mechanical demands during the concentric or the eccentric phase of the movement. As shown in other isoinertial equipment, flywheel devices show a mechanical overload as the moment of inertia is increased. However, it is not easy to express the load intensity as a percentage of “something” (such as the one-maximum repetition in free weights). For this purpose, the peak acceleration can distinguish among different inertial loads and fatigue levels along with repetitions and sets. In relation, the load of a flywheel resistance training device has to be accounted for considering the shaft’s width and the moment of inertia used. A conical pulley will vary the axis and, consequently, the load, over the exercise range of motion compared to a horizontal cylinder device. On those, higher peak torque can be found. Finally, caution should be taken when monitoring the eccentric overload, that has been a topic of interest. Not all the individuals experiment an eccentric overload, and it is important to highlight that the only way to achieve eccentric overload with flywheel devices is by modifying the tempo or the range of motion during the eccentric phase.

This paper considers the problem of a mechanical system design with a variable moment of inertia. The suggested system consists of a rotating disc with the ability to change the angle of inclination by means of a rod and a slider mounted on the rotation axis. Design equations and techniques are described, making possible the dynamic substitution of the mass of the connecting rod by two concentrated masses. By application of the suggested dynamic model of the coupling rod, a weightless link with two concentrated masses has been obtained. This allows a more precise estimation of the influence of the connecting rod position on the moment of inertia about the rotation axis. A numerical example illustrates the proposed design of variable moment of inertia flywheel.

Vertical rotors are often used as components of energy machines or flywheels for energy storage. Application of the contactless bearings makes it possible to minimize resistance against their rotation, wear, and energy losses. The advanced technological solution consists in utilization of permanent magnetic bearings or magnetic rings lifting the vertical rotors mounted in rolling element bearings to reduces their axial loading. The carried out research was focused on investigation of a rigid rotor supported at its upper end by a rolling element bearing inserted in a squeeze film damper and coupled with the stationary part by a shear magnetic bearing at its lower end. The bearaing is composed of two permanent magnets, one is attached to the stationary part and one to the rotor. The magnets are mutually attracted, which returns the rotor always to the equilibrium position during its vibration. In the developed computational procedure the rotor is represented by an absolutely rigid body and the permanent magnets by electric coils powered by equivalent current. The frequency response shows that application of the proposed magnetic bearing reduces amplitude of the rotor vibration in the range of lower velocities.

The paper presents the free oscillation analysis of the reduced torsional system in the crankshaft of a six-cylinder piston internal combustion engine with a liquid or rubber (internal friction) damper mounted on the toe. Installing a torsional vibration damper on the sock of the crankshaft changes the frequency of free oscillations, and in addition, when installing a rubber damper, another mass of the torsional system is added with the coefficient of rigidity of the rubber layer and the moment of inertia of the damper flywheel. At the same time, for liquid torsional vibration damper, the flywheel which has no direct connection with the toe of the crankshaft, for the calculation of free oscillations to the moment of inertia of the sock it is necessary to add a half the moment of inertia of the flywheel. The order of selection of optimal damping coefficients, namely the moments of inertia of the damper flywheel and damping coefficients of silicone fluid, is considered. For the rubber (internal friction) damper, the necessary parameters include the moment of inertia of the flywheel, the stiffness coefficient of the rubber layer and the damping coefficient. The free oscillations are considered in a complex form, which allows obtaining a function after the transition to real values that can be taken as a function of optimizing the parameters of the liquid or rubber damper. In this case, at the optimum damping or maximum energy dissipated in the damper, the amplitude of torsional oscillations of the crankshaft toe is reduced as much as possible. Using this approach allows for a significant reduction in the number of calculations with different damping coefficients and chooses the most optimal results.

The main disadvantage of existing rescue devices for the emergency evacuation of people from high-rise buildings in the event of a fire hazard is that they are not intended for mass evacuation, but are rather the devices for individual use. Evacuations are usually carried out by controlled descent with an irrevocable loss of braking energy. Therefore, these devices cannot be used due to the limitations of their capabilities, as they are not adapted to the specific conditions of offshore drilling platforms. A review of scientific papers and patents devoted to this issue showed that there are gaps in their coverage of automation issues that improve the reliability of rescue devices. A team of Bauman Moscow State Technical University developed basic requirements for the design of modern rescue devices for offshore drilling platforms. The design of a mechanical rescue device, patented in the Russian Federation, meets these requirements.

Background Given the severe economic and performance implications of hamstring injuries, there are different attempts to identify their risk factors for subsequently developing injury prevention strategies to reduce the risk of these injuries. One of the strategies reported in the scientific literature is the application of interventions with eccentric exercises. To verify the effectiveness of these interventions, different eccentric strength measurements have been used with low-cost devices as alternatives to the widespread used isokinetic dynamometers and the technically limited handheld dynamometers. Therefore, the purpose of the present systematic review was to summarize the findings of the scientific literature related to the evaluation of eccentric strength of hamstring muscles with these new technologies. Methods Systematic searches through the PubMed, Scopus, and Web of Science databases, from inception up to April 2020, were conducted for peer reviewed articles written in English, reporting eccentric strength of hamstrings assessed by devices, different to isokinetic and handheld dynamometers, in athletes. Results Seventeen studies were finally included in the review with 4 different devices used and 18 parameters identified. The pooled sample consisted of 2893 participants (97% male and 3% female: 22 ± 4 years). The parameters most used were peak force (highest and average), peak torque (average and highest), and between-limb imbalance (left-to-right limb ratio). There is inconsistency regarding the association between eccentric hamstrings strength and both injury risk and athletic performance. There is no standardized definition or standardization of the calculation of the used parameters. Conclusions The current evidence is insufficient to recommend a practical guide for sports professionals to use these new technologies in their daily routine, due to the need for standardized definitions and calculations. Furthermore, more studies with female athletes are warranted. Despite these limitations, the eccentric strength of hamstring muscles assessed by different devices may be recommended for monitoring the neuromuscular status of athletes.

In this chapter the major currently available energy storage systems are briefly summarized.

Increasing the efficiency of IC engines is a frequently discussed topic, and one of the approaches taken is to modify the thermodynamic work cycle of the engine so that it resembles the ideal cycle more closely. This paper attempts to achieve that by altering the kinematics of the piston-crank mechanism by introducing an epicyclic non-circular gear train between the crank and the flywheel. The addition of the non-circular gears alters the work cycle by introducing a state of dwell during key points of the cycle. Possible gear shape solutions were calculated using a known, periodic function to express the gear transmission ratio. The final result was an epicyclic non-circular gear train that has a noticeable effect on the kinematics of the piston-crank mechanism resulting in an increase of the engines work cycle efficiency.

Rotational inertia dampers have been proposed as passive vibration absorbers. Traditional rotational inertia dampers come in different configurations, but all feature a mechanical device called an inerter. The inerter is a two terminal device that can produce a large effective mass via the transformation of translational motion to the rotation of a flywheel. Despite the effectiveness of rotational inertia dampers at reducing the response of structures, there use has potential drawbacks. The inerter increases the effective mass of a system and, therefore, reduces the natural frequencies of that system; this shift in natural frequency is not always desirable. Furthermore, energy that is transferred to the inerter as rotational kinetic energy is transferred back to the structure when the structure’s motion slows, which can drive the response of the structure. To address these issues, one-way rotational inertia dampers have recently been proposed and investigated. In the one-way rotational damper, energy is transferred to a flywheel as rotational kinetic energy in a manner in which it cannot transfer back to the structure. In addition, the one-way rotational damper is not always engaged with the structure; thus, the effective mass of the system changes during its response. Due to these changes, also known as state-switching, it is not straightforward to evaluate the response of the system or its effective frequency. In this study, the effect of the one-way rotational inertia damper on the frequency and response of the base structure is investigated with numerical analyses.

Automotive industry drives development towards down-sized and down-speeded engines and higher cylinder pressure. This leads to increased torsional vibrations and therefore puts higher demands on the drivetrain vibration capabilities. The paper presents the results on the study of the limits of torsional dynamics absorbers for vibration attenuation in drivetrain systems obtained by using global sensitivity analysis and multiobjective optimization. The global sensitivity analysis comes with a mapping between the total sensitivity indices of the vibration attenuation measures of a drivetrain system and mass-inertia, stiffness and damping parameters of a torsional dynamics absorber. The multiobjective optimization is resulted in Pareto fronts showing the trade-off between the measures of vibration attenuation and energy losses making possible to identify the limits of the quality of performance of a torsional vibration absorber for a drivetrain system operating on a set of engine input loads. Detailed numerical results are presented on study of application of a dual mass flywheel for heavy-duty truck drivetrain systems in operating engine speed range up to 2000 rpm. The third engine order vibration harmonic is in focus of analysis as one of the most significant contribution to the oscillatory response in drivetrains of heavy-duty trucks.

The characteristic of all bodies having a certain mass is that during its movement, in addition to all forces acting, the force of inertia also acts. In the case of the translational motion of the body, such as the movement of a vehicle along a straight line, the force of inertia acts. However, in the case of body rotation, the term moment of inertia is introduced. In order to simulate the inertia of a quarter of a moving vehicle moving, but in a laboratory test, this paper presents a methodology for simulating the inertia of a vehicle using a flywheel mass, i.e. a moment of inertia. In this particular case, an analysis of the required rotational speed of the flywheel was performed in order to simulate a specific speed of vehicle and to test the working characteristics of the disc brakes. Knowing the speed of the translational moving of a quarter of the vehicle model and knowing the characteristics of the flywheel mass, and applying the basics of kinetic energy of these two types of motion, a solution was reached about the required rotation speed of the flywheel mass in order to simulate the movement of the vehicle. The conclusion about the rotation speed of the flywheel mass in order to simulate the movement of the vehicle was reached by deriving the equations from kinetic energy.

Cylinder deactivation is a technology that allows the engine displacement to be varied to match vehicle acceleration and power demand. This is typically accomplished by turning off banks of cylinders, to go from, say, an 8-cylinder engine to a 4-cylinder engine and vice versa. Dynamic Fuel Management is a term used to describe the continuous use of cylinder deactivation in such a way that various cylinders are shut off in a variety of combinations, maximizing fuel economy and avoiding switching between banks of cylinders. Such an engine operates with lower pumping losses and maximizes the potential for regenerative braking energy capture. In the present work we explore the synergies of coupling an engine equipped with Dynamic Fuel Management, to an electrified driveline hybridized with a 48 V motor. The so-called P1 architecture is investigated, wherein the motor is connected to the engine crankshaft at the flywheel between the engine and transmission. We use detailed Matlab models combined with an optimization algorithm that determines engine/motor torque arbitration to identify optimal powertrain states to maximize fuel economy. We show that the combination of Dynamic Fuel Management and hybridization can provide a substantial fuel economy improvement.

A linear control problem is considered in the presence of exposure from an uncontrolled disturbance. It is known only that its values belong to the given connected compact. The payoff is the absolute value of linear function at the end time of the controlled process. It’s believed that one breakdown is possible, which leads to a change in the dynamics of the controlled process. The time of occurrence of breakdown is not known in advance. Control is constructed based on the principle of minimizing the guaranteed result. The opposite side is the disturbance and the moment of occurrence of a breakdown. The necessary and sufficient conditions are found under which an feasible control is optimal. As an example, the problem of controlling a rod, which is rigidly attached to an electric motor rotor, is considered. A rotary flywheel is attached to the other end of the rod. The voltages applied to the rotor and flywheel are control. As disturbance, we take the nonlinear addend in the equations of motion. The goal of choosing controls is to minimize the modulus of the deviation of the angle formed by the rod and the vertical axis from the given value at a fixed time moment.

This paper describes the management of a self-sufficient confined micro-grid (MG) including both controllable and uncontrollable sources, having such sources Like the diesel engine generator (DEG), flywheel (FW), battery storage system (BSS), fuel cell (FC), water electrolyzer (WE), wind and solar are used. Wind, solar, FC and DEG have power producing source and WE, FW, BSS as an energy storage component. The created hydrogen through a Water Electrolyzer is utilized like fuel of an FC. The power system’s frequency fluctuates for the unexpected change in load burden and a real power. The exit power of DEG, FC, BSS, FW, and power consumed by WE is directed through utilizing a controller with the end goal that the frequency is under control. Compensator is proportional integral derivative (PID) utilized through a Technique of Robust Response Time. Robust Response Time (RRT) is utilized for adjusting of planned micro grid’s gains of PID. This employ the Chien-horns-Resnick (CHR) setting with 20% peak shoot. The performance of RRT based PID strategy is contrasted with MB-LDR and CLASSICAL methods and the outcome of RRT technique PID have got preferable result than the existing two methods of PID controller.

This paper presents an hybrid energy storage system for the integration of renewable-based power plants in power networks. A hybrid energy storage system is defined as that able to integrate and maximize the contribution of a heterogeneous grouping of storage systems. The services which this hybrid solution is able to perform are identified and then related to a specific storage technology which have the best potential to solve the issues created by the intermittent renewable generation. The presented solution combines three different storage technologies, a lead-acid battery pack, a flywheel and a set of supercapacitors. The description of the system is complemented by a study case, for the performance analysis of the set of supercapacitors.

Engine start quality and seamless engine start/stop are key elements of drive quality and customer acceptance in today’s electrified propulsion architectures. Two novel mechatronic devices have been created for premium engine start/stop. One concept uses a motor/generator in place of the traditional alternator, coupled to a mechatronic switching device for selectable geared or belted operation of the motor/generator. The second starter concept uses a two-speed gear scheme inserted between the starter motor and crankshaft flywheel for smooth engine starts. In the present work, the use of these starter devices in vehicles with sailing/coasting mode as well as in mild hybrid propulsion systems is described. Sailing/coasting mode of operation is enabled by the quick engine re-start capability of these starters allowing seamless switching between fuelled and unfuelled engine operation. This could reduce fuel consumption by about 3–6% on the NEDC driving cycle, without regenerative braking. One may further hybridize the propulsion system by adding a battery for storing regenerative braking energy. Using such an architecture, a 6–8% fuel economy improvement on the WLTP certification driving cycle may be achieved, depending on voltage and power levels implemented, as well as energy storage systems included.

Dynamic stabilisation of gyroscopically stabilised single track (monorail) vehicles necessitates accurate tilt angle control on transitions between track sections with different curvature to eliminate or to effectively damp unwanted sideways swaying of the vehicle caused by flywheel nutation and by the control lag arising from feedback control loop. In this paper, a feedforward tilt control method is proposed, which utilises on-the-go running rail image analysis to predict an oncoming rail curvature change and to generate an input for the flywheel gimbal servo drive to get the vehicle cant adjusted to the rail curvature beforehand. This approach will allow such vehicles to be used in high-speed transportation, where their advantages could be manifested in full.

Special problems of rotational motion. The most important properties of a flywheel, which can be used to store kinetic energy and to make the rotational motion smoother by reducing the speed of fluctuations, are discussed. Stability problems caused by a change in the load torque is also investigated. If the shaft is not rigid further problems occur. Laval’s theorem and the gyroscopic effect of the rotational motion are also considered.

Vibrations analysis of rotating machinery offers abundant information about failure root-causes and asset condition, as well as aiding early failure detection and prognosis. Vibration based condition monitoring normally focuses on lateral vibrations, as measurement techniques and technologies are highly developed and standardized, in comparison with torsional vibration measurement. However, the later describes the effects of the main forces acting on rotating machines and the primary shaft function, i.e. transmitting torque. The present work focuses on torsional vibration measurement and analysis of a 110 kW primary coolant circuit centrifugal pump of a Nuclear Research Reactor (comprising impeller, flywheel and motor shafts, linked by flexible couplings) during start-up and operation. A measurement technique and a methodology for condition monitoring based on torsional vibration analysis are presented. A modal analysis based on a Finite Element Model is presented as support tool for this kind of technology, showing high dependence of the shaft torsional behaviour with the shaft flexible coupling stiffness. Experimental results during the pump start up and steady state operation at different loads are presented, showing torsional vibrations of the pump shaft close to rotor’s first torsional mode. This kind of analysis yields vital information about the asset’s condition that doesn’t show up in lateral vibration data.

The first known utilization of flywheels specifically for energy storage applications was to homogenize the energy supplied to a potter wheel. Since a potter requires the involvement of both hands into the axisymmetric task of shaping clay as it rotated, the intermittent jolts by the potter foot meant that the energy supply would have short-term peaks when a pulse of energy is supplied, then it will trail off during the time it takes the potter foot to reach the wheel again. The friction from the bearings of the setup and the applied torque from the potter hands will rapidly consume the energy supplied by the initial kick. The addition of a flywheel is expected to assist in the stabilization of the operation of the device. The flywheel in fact is simply just an extra mass that will keep the kinetic energy of the system, defined as \( \frac{1}{2}I\omega^{2} \), as steady as possible by normalizing the discrepancy of energy charge/discharge levels. In this particular case, this is achieved through increasing the physical inertia of the system (the resistance of the system to any change of its motion).

The torsional vibrations generated by combustion engines installed in vehicles have an undesirable effect on the life and reliability of individual components. Vibration and excited noise reduce the comfort of the operator and crew. The subject of torsional vibration reduction is therefore highly current. One of the options for reducing torsional vibrations is the current use of dual mass flywheels that are included between the combustion engine and the vehicle’s gearbox. An alternative solution to the reduction of torsional vibration is the use of a pneumatic dual mass flywheel. The pneumatic dual mass flywheel is characterized by the fact that it is possible to change its properties during the drive operation. For the purpose of investigating the use of dual mass flywheel in combustion engines, it was necessary to create experimental devices and methodology to identify their properties. The experimental device is possible to identify the operational, strength and expansion properties of pneumatic dual mass flywheels.

The circuit elements in circuits, we analyzed thus far, are conductively coupled. Conductors are used to connect elements. Circuit elements can also be connected through magnetic fields, called magnetically coupled. An inductor is basically a conducting coil. The induction of a voltage in another inductance by the current flowing in an inductance is mutual induction. A flywheel is a mechanical device that stores rotational energy and returns it to the system. Similarly, an inductor stores magnetic energy and returns it to the system. It does not dissipate energy like a resistor. While a resistor is required to limit the current in the circuit, an inductor smooths the flow of current.

New powertrain design poses new challenges in terms of driveline vibration or ultimately in terms of NVH (Noise Vibration Harshness). Current state of the technology for vibration damping in car powertrains is the so-called Dual Mass Flywheel (DMF). The paper deals with creation of MBD model of double mass flywheel based on CAD model of dual mass flywheel produced by ZF. Parameters of virtual model are tuned and compared with experimental measures of dual mass flywheel. Second part of paper deals with dynamic simulation of DMF. Model used for dynamic simulation consists of two bodies and torsion spring with stiffness computed from simulation of full DMF model.

This chapter describes the main components of a microgrid, focusing on their dynamical behavior, a key concept in control engineering and particularly in MPC. Mathematical models of renewable generation devices (photovoltaic panels or wind turbines), and also energy storage systems with high penetration in microgrids (batteries, ultracapacitors, and hydrogen-based systems) are presented in detail in the chapter. These models are the base for the development of the software included in the companion toolbox \(Sim\mu grid\). Brief descriptions of alternative storage systems, such as flywheels or compressed air, are also included. Operational issues in energy storage systems to avoid non-adequate use, prevent the degradation of the devices, and improve their performance, reliability, and lifespan are also addressed. These concepts are of considerable importance for the design of MPC controllers, and they will be widely used throughout the book.

The most desirable characteristics of today’s power system with distributed energy resources (DER) forming the microgrid is the reliability of the power supply and immunity to various power quality(PQ) issues. It is important to examine PQ issues arising from the introduction of DER and behavior of microgrid with penetration of various loads. In this chapter, reader is introduced to major power quality issues in the microgrid. A number of solutions to tackle these issues and their operating principle are also explained. In addition to the conventional power quality issues, load pulses are frequently encountered and need to be tackled with great care in microgrid. Hence, the hybridization of Energy Storage System (ESS) with different power storage devices such as the ultracapacitors (UCs), Superconducting Magnetic Energy Storage (SMES) devices, and high speed Flywheel Energy Systems (FESs) is proposed to dynamically compensate the power flow balance.

In the present research the Mathematical Modeling & Simulation of Chaff Cutter Energized by Human Powered Flywheel Motar has been studied. The machine system consists of a Human Powered Flywheel Motor as energy source. This source comprises of a Bicycle-drive mechanism with speed increasing gearing and a Flywheel. This energy source energizes the process unit through a spiral jaw clutch and torque-amplification gearing. The operator pumps human energy to the flywheel at a convenient input power level for about one minute. After enough energy is stored, pedaling is stopped and the energy in the flywheel is made available to the process unit by engaging the spiral jaw clutch[1].

We consider the problem of controlling a rod attached to a rotor. A rotating flywheel is attached to one end of the rod. The rotor is controlled by the first player. The flywheel is controlled by the second player. The goal of the first player is to bring the rotor to a vertical position at a given time. The goal of the second player is the opposite. This problem is an example of a more general linear differential game with a one-dimensional aim. Using a linear change of variables, this problem is reduced to a single-type one-dimensional differential game with a non-convex terminal set, for which we have found the necessary and sufficient conditions of termination and constructed the corresponding controls of the players.

The design of a friction-powered robot is proposed. The robot is driven by a motion of internal masses. It has one unbalanced rotor and one flywheel. A mathematical model of its plane-parallel motion is constructed. Equations of translational motion are studied. Angular accelerations of rotating structural elements are selected as control functions. A control variant is proposed, in which the forward movement of the body is realized.

This article will initially consider the life-saving appliance dynamic model accompanied with computation and analysis of its variables. This life-saving appliance can be used in case of fire on the drilling platforms. The flywheel energy storage converts energy of descent to the rotational energy of the flywheel. After the launch, stored energy can be used to rotate the propeller of survival capsule to increase the distance from the fire. This kind of construction allows decreasing the number of maintenance operations. Moreover, there can be lack of energy in emergency cases. It points out one more profit of this appliance. This life-saving appliance is also analyzed from the economical point of view, and the authors have suggested an economical efficiency Criterion as a marker. The results of variables computation and modeling should be taking into account while developing the construction. The modeling analysis shows the great potential of this life-saving appliance as reliable and safe.

Background Strength and power development are abilities important for athletic performance in many sports. Generally, resistance training based on gravity is used to improve these qualities. Flywheel training instead utilizes kinetic energy transferred to a flywheel. This allows for eccentric overload and variable resistance throughout the movement. The aim of this review was to identify the effects of flywheel training on multiple strength-related variables affecting athletic performance. The meta-analysis investigates the effects on (1) muscle growth (cross-sectional area (CSA) and volume/mass), (2) maximum dynamic strength, (3) development of power, (4) development of horizontal movement, and (5) development of vertical movement. Methods The meta-analysis includes 20 experimental studies that met the inclusion criteria. The quality of included studies was ranked according to the PEDro scale. Possible bias was identified in Funnel plot analyses. To enable the compilation of all results analyses, the random effect model was carried out using the software Review Manager Version 5.3 and presented with Forest plots. Results Flywheel training for a period of 4–24 weeks shows statistically significant increases in all strength aspects. Effect sizes were for hypertrophy, CSA 0.59; volume/mass 0.59; maximum strength 1.33; power 1.19; horizontal 1.01 and vertical movement 0.85. The evidence is particularly strong for beneficial effects from flywheel training in the development of maximal strength and power in trained younger individuals, and utilization of this training modality in shorter more intensive blocks. Conclusions Flywheel training is an effective method for improving several aspects of strength and power with importance for sports performance. Electronic supplementary material The online version of this article (10.1186/s40798-018-0169-5) contains supplementary material, which is available to authorized users.

During the commissioning of a diesel hydrotreating unit, high frequency vibration was detected on the Hydrogen makeup compressor, causing machine shutdown and alarming levels of vibration on the piping system. The high frequency components – concentrated between 11× and 15× the compressor speed – were present even during no-load operation and reached values around 3 to 4 times the fundamental frequency amplitude. The high frequency made impossible the improvement of the piping by inclusion of supports. Pressure pulsations, initially believed to be the most likely root cause, were measured and did not show any abnormal values. The measurements ultimately showed that the compressor itself seemed to be the main source of the high frequency. The crankshaft’s second torsional frequency and flywheel’s first bending mode were changed by redesign of these elements, which also showed no positive result. Several further tests were carried out in order to assess the main cause of the vibration. Spectrum analysis during startup and shutdown, PxV diagram evaluation and bump tests finally revealed that a complex interaction between two crankshaft torsional natural frequencies and two structural natural frequencies were the cause of the problem.

The objective of this work is the fault diagnosis in diesel engines to assist the predictive maintenance, through the analysis of the variation of the pressure curves inside the cylinders and the torsional vibration response of the crankshaft. Hence a fault simulation model based on a zero-dimensional thermodynamic model was developed. The adopted feature vectors were chosen from the thermodynamic model and obtained from processing signals as pressure and temperature inside the cylinder, as well as, torsional vibration of the engines flywheel. These vectors are used as input of the machine learning technique in order to discriminate among several machine conditions, such as normal, pressure reduction in the intake manifold, compression ratio and amount of fuel injected reduction into the cylinders. The machine learning techniques for classification adopted in this work were the multilayer perceptron (MLP) and random forest (RF).

Humanoid robots should prevent damage during falling forwards, which will improve the ability of serving people on various occasions. In this paper, we analyze different landing positions, and propose a falling forwards protection strategy for humanoid robots. Falling forwards is divided into two phases: the knee landing phase and the chest landing phase. The parametric optimal strategy based on telescopic inverted pendulum with flywheel is used to plan the motion of robot in the first phase to reduce the impact. Inverted pendulum with flywheel and fixed length is adopted in the second phase. The simulations tested on the BHR-6P (BIT Humanoid Robot 6 Prototype) platform validate the effectiveness of the presented strategy.

The important feature of wind energy is the fluctuation of the power produced over time. The stability of the network is based on the balance between production and consumption. For this, the idea of storage has been exploited. Owing of this, in first stage, an ANFIS controller is proposed for speed control in order to ensure the real-time tracking of the optimum operating point and MPPT giving online a maximum production of electric power for different wind speeds. In second stage, we present a new solution for the wind energy storage based on short term storage. This solution is based on the use of the intelligent flywheel based on fuzzy logic. The new Fuzzy FESS can be used not only to minimize wind power fluctuations, but also to adjust the frequency and the voltage of the grid during operating conditions. Simulation testes on a 1.5 MW DSIG system are given to illustrate the feature of control method and the large interest of energy storage in such WECS.