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The use of regenerative braking and recent electrohydraulic or electromechanical brake-by-wire systems with enhanced dynamics enables improved antilock braking control performance in electric vehicles. However, the possible benefit is often limited by suboptimal control architectures with separate distributed controllers for electric motor (EM) and friction brake torque requests. Furthermore, oversimplifications in synthesis models for brake control design constrain the achievable performance. Instead, to date, threshold-based algorithms are widely used in modern production vehicles despite having been designed for slower hydraulic brake systems originally. To exploit the full potential, this work proposes a continuous nonlinear control design using input-output linearization for robust wheel speed tracking control. The design uses a unified controller for the redundant actuators. In addition, it explicitly considers drivetrain oscillations induced by regenerative braking using onboard EMs in the synthesis model. The stability for the resulting zero dynamics is shown through the Lyapunov analysis. The nonlinear controller is augmented by a subsequent control allocation for splitting the control effort on the redundant actuators. The allocation design ensures consistent control performance for both regenerative braking and hybrid braking while simultaneously aiming for high-energy recovery. The overall antilock braking control design is implemented in an electric test vehicle. Its tracking performance, disturbance attenuation, and robustness are experimentally validated through various emergency braking maneuvers on different road surfaces.

Automotive engineering, the protection viewpoint has been thought of as a main would love being developed of another vehicle. each single framework has been thought of and created to meet security conditions. rather than having air sacks, nice suspension frameworks, nice taking care of and safe cornering, one amongll|one amongst|one in each of} the foremost basic frameworks in an exceedingly vehicle is that the stopping mechanism. The wheel/center hub is believed to be a brake circle (or rotor), usually factory-made from cast iron or innovative composites. Grinding material as a restraint (mounted on an instrument referred to as a brake caliper) is unambiguously compelled using hydraulically, pneumatically or electromagnetically operated to stop the wheel against the various sides of the hover. The analytical, numerical, simulation techniques and non– linear improvement techniques applied to bolster heat transfer rate and efficiency of the hydraulic brake ar studied.

The design dimensions of the executive hydraulic cylinders of the brake system of heavy-duty mining dump trucks cause high fluid flow during the braking process. Therefore, dimensions of the anti-blocking system modulator spool pair require unique electromagnets or hydraulic amplifiers to control. These solutions do not allow the required modulator performance. Thus, a modulator scheme with a division of the flow of fluid from the source to the brake cylinders was developed. This scheme allows during emergency braking passing, an additional amount of fluid to cylinders through the valve, installed parallel to the main valve upon pressure increase phase and controlled by the pressure difference. The task is to develop a method for calculating the main structural dimensions of a modulator. The calculation of the valve of the second cascade, installed in parallel to the main stage, is carried out for the emergency braking mode with the maximum flow rate to ensure the required performance of the braking system. The balance of fluid flows equations is compiled at the key points. The flow rate of the fluid through each of the valves is determined by the Torricelli formula, and the pressure difference across the valves is assuned equal. The obtained relations allows building a family of Q-p curves, which can be used to select the diameter and stroke of the additional valve depending on the flow rate in the brake system.

During ground tests of TV3-117 gas turbine engines on hydraulic brake systems, self-oscillations of the rotor speed of a free turbine and the parameters of a turbocharger in the area of operation of the free turbine speed regulator are often recorded. One of the reasons for the development of self-oscillations in the automatic control system of a free turbine is the discrepancy between the loading characteristics of the hydraulic braking unit and the loading characteristics of the helicopter main rotor. During ground tests, the object of regulation is a free turbine with a connected hydraulic brake rotor. When the engine is operating as part of a helicopter power plant, the control object is a free turbine with a connected main rotor rotor. Changing the parameters of the controlled object without appropriate correction of the controller parameters can lead to unsatisfactory dynamics of the automatic control system. Another reason for the development of self-oscillations is the nonlinearity of the characteristics of the elements of the automatic control system. The article presents a mathematical model of the system for automatic control of the speed of a free turbine, taking into account the nonlinear features of the characteristics of real regulators. Computational studies of the influence of the rupture of the static characteristic and the zone of insensitivity of the regulator on the development of self-oscillations in the automatic control system of the speed of a free turbine during ground tests of a helicopter engine are carried out. Recommendations are given on the choice of parameters of the free turbine speed regulator to prevent the occurrence and development of self-oscillations of the speed of the turbocharger and free turbine.

Fault diagnosis of hydraulic brake systems using a machine learning approach is presented in this study. A real vehicle brake system was considered for the study. The vibration signals were acquired from the brake system under various fault conditions using a piezoelectric type accelerometer. The meaningful statistical information was extracted from the raw signals using the feature extraction techniques. The feature selection process was then carried out using the effect of the number of features study. The extracted features were classified using the various functions based algorithms, namely, Sequential Minimal Optimization (SMO), Multilayer Perceptron (MLP), and Logistics. The results were presented and compared. The logistic algorithm produced a maximum classification accuracy of 85.52% compared to SMO and MLP.

Multi-source driving (MSD) yaw system is widely used in large-scale wind turbines. However, due to the complex coupling effect of mechanical, electrical, and hydraulic, there is a knowledge gap on the dynamic process of the MSD yaw system. To fill this gap, a dynamic coupling model of the MSD yaw system is established. In this model, multi-way power source subsystems, transmission gearbox subsystems, and hydraulic brake subsystems are established, and the coupling of multi-way yaw subsystems are realized. Based on this model, different yaw angle control modes are studied, including comparison control and servo control. To further reflect the dynamic process in-service condition, the MSD yaw system model is integrated into a wind turbine model. An approximate solution for calculating yaw load is also presented. Through this study, the results show the established MSD yaw system model can work effectively. The difference of gear meshing gaps directly affects the distribution of yaw load. The dynamic response of the yaw system, including yaw position, yaw speed, and yaw acceleration, is affected by the changing amplitude and frequency of yaw load, but the large inertia of yaw system can restrain the fluctuation of yaw dynamic response to some extent.

The brake disk is a key part of the braking mechanism, the task of it is to slow or stop the vehicle's wheels, on the one side, while the heat produced during the process is dissipated. In this regard, the brake pads are pressed by mechanical strength on the surface of the brake disks. This study aims to develop a model of a disk brake by use of CATIA V5, on the model, finite element analysis (FEA) done by ANSYS 19 then compare it to the findings gained by the original tests. A computational thermo-mechanical study was conducted on this research by use of ANSYS software for disk brake mounting inside a hydraulic brake system. This study is designed to provide insight into the heat flow behavior within and around a brake disk during brake testing and simulations. Two cases have been analyzed. Experimental evaluations of a hydraulic brake system can verify the simulation models. Together with the ten successive brakes, numerical as well as experimental tests are made. The findings permit a comparison of the numerical and experimental temperatures to verify the models.

The results of experimental studies of the static characteristics of the speed controller of a free turbine of the pump-controller of the HP-3 type, intended for a turboshaft gas turbine engine of the TВ3-117 type, are presented. When conducting acceptance tests of engines on hydraulic brake units, malfunctions are recorded, which manifest themselves as steady fluctuations in the speed of the turbocharger and free turbine rotors in the area of the free turbine regulator. Checking the pump-regulators according to the manufacturer's acceptance test report does not reveal the cause of this malfunction. As a result of the analysis of experimental static characteristics, it was revealed that the actual static characteristics of real regulators are very different from each other even within the acceptable values of the acceptance test protocol and have characteristic features: different values of statism, hysteresis, as well as deviations from linearity - breaks and fractures. Small statism of the regulator (large gain) reduces the margin of stable operation of the automatic control system, which contributes to the development of self-oscillations, and at certain values of the dynamic parameters of the engine, the control process may become unstable. The hysteresis of the static characteristic of the regulator plays an important role in vibration damping. It should be positive, since it is conditiones by the frictional forces in the hydraulic drive of the main metering needle. Therefore, a zero or negative hysteresis of the static characteristic of the regulator indicates a defect in the unit, which is confirmed by a tendency to self-oscillation. Non-linearity of the static characteristic of the regulator can lead to unsatisfactory operation of the automatic control system by the engine. It is shown that the static characteristic of the speed controller of a free turbine is a confirmation of the quality of manufacture or repair of pump-regulators of the HP-3 type during acceptance tests.

For diagnosing car braking systems, bench methods have become the most widespread, and on power stands with running drums. The main disadvantage of these methods is the high cost of brake stands with low quality diagnostic information. At the same time the method of diagnosing brake systems on change of angular speed of the hung up wheels is perspective. But the considered method does not have a sufficiently complete theoretical justification, especially for cars with hydraulic brakes and therefore requires research. Therefore, the work substantiates the diagnostic modes and diagnostic parameters, obtained analytical dependences of the process of braking car wheels with hydraulic brakes, which describe the change in the angular deceleration of the suspended wheels over time in different parts of the brake diagram and the delay time of the brake system. The mathematical model is based on the differential equation of motion of the braked wheel when braking a car with a connected transmission (with clutch engaged) on a straight horizontal section of road. The change in braking torque during braking is determined by the nature of the pressure change in the drive. When braking the wheel, the braking force acts on the radius of the brake drum. The obtained analytical dependences make it possible to study the influence of various factors of the technical condition of brake systems on the performance of the braking process. In order to substantiate the diagnostic modes and diagnostic parameters, analytical dependences of the process of braking car wheels with hydraulic brakes have been developed, describing the change of angular deceleration of suspended wheels in time at different parts of the brake diagram and time delay of the brake system. The obtained analytical dependences make it possible to study the influence of various factors of the technical condition of brake systems on the performance of the braking process.

In order to improve yaw stability of electric vehicles with in-wheel motors, a yaw moment fuzzy control method based on yaw rate and side-slip angle is designed. A hierarchical control structure was set up. The upper layer is motion tracking layer, it obtains required additional yaw moment based on the fuzzy control theory according to current status feedback of vehicle and ideal status of reference model. The lower layer is a torque distribution layer that uses the weighted least squares method to optimise moment distribution by adopting an in-wheel motors/hydraulic brake system combined control strategy, with full consideration of all restraints. A rapid control prototype test bench is designed based on dSPACE system, simulation experiments were conducted under typical test work conditions. The simulation result shows that compared with even torque distribution and the optimal torque distribution involving the motor only, the optimal torque distribution control strategy of the combined in-wheel motor and the hydraulic braking system can effectively improve the stability of wheel-motor driven electric vehicles.

A novel compact initiative braking system orienting intelligent vehicles and autonomous driving is revealed. The delicate arrangement of on – off switch valves guarantees precise hydraulic pressure modulation. Integrated stroke simulator provides a well-tuned pedal force feedback. The fallback level is intensively designed to be nondegraded. A hierarchical control frame with the underlying hydraulic controller is designed to govern operation procedures. The underlying hydraulic controller is set up based on adaptive gain scheduling proportion differentiation controller and logic threshold control. Hardware-in-loop tests are carried out in full perspectives. The test result of slope-sine combination tracking shows that, compared with the conventional proportion integration differentiation controller, the designed underlying controller achieves higher pressure modulation accuracy with no chattering effect. Controller robustness to accumulator pressure fluctuation is proven by the dual-cylinder tracking test. A batch of step-response tests under different accumulator pressures shows a rapid pressure building capability in emergency situations under all pressure range. The fail-safe test result indicates that the conventional hydraulic brake can be restored in 1.5 s with the operation of the driver, which significantly increases the margin of brake safety for highly autonomous vehicles. The regenerative braking test result suggests the immense potential of the developed system in an application to electrified vehicles.

In ground tests of turboshaft gas turbine engines, an unsatisfactory operation of the system for automatically controlling the speed of a free turbine, which manifests itself as steady-state fluctuations in engine parameters, is often noted. To absorb the power generated by a free turbine, hydraulic brake systems of various designs are used in ground tests of aircraft turboshaft gas turbine engines. Ground tests of aircraft turboshaft gas turbine engines with the use of such hydraulic brakes can result in emergency modes of automated engine control in the area of operation of a free turbine speed regulator. Mismatch between the hydraulic brake loading characteristics and the loading characteristics of the rotor driven by a free turbine of the engine is the main cause of emergency operation of automated control systems. Changing the design of the hydraulic brake in order to change its characteristics is a very laborious and expensive task. Therefore, the paper considers the possibility of providing the specified characteristics of the hydraulic brake with simple automation. The presented experimental loading characteristics of the hydraulic brake and the helicopter rotor show their significant difference in terms of gain. To eliminate this difference, a possibility of modeling dynamic parameters of rotors by simple automation means was considered. To solve this problem, a linear dynamic model and a block diagram of an automated hydraulic brake control system for ground testing of turboshaft gas turbine engines were elaborated. The law of regulation of the hydraulic brake loading was substantiated. A structurally dynamic diagram of the developed automated control system was presented and calculation formulas for determining the regulator parameters were given. Transient characteristics of the hydraulic brake unit without automation means and with the use of an automated loading control system were calculated. The presented calculation results have shown that the use of automation make it possible to fully emulate characteristics of the helicopter rotors.

The aim of the article is to find the factors, that influence the change in the established deceleration of motor vehicles, in the process of improving their braking system, to outline the problems of inconsistencies in the statistical database of motor vehicle deceleration, which are used by forensic experts for calculations within the auto technical examination, their braking systems and, accordingly, changes in the braking parameters. In this article, authors explain the problem of discrepancy between the statistical database of motorcycle speed-reduction parameters, which is used by forensic experts to make calculations within a vehicle examination, and the parameters of modern motorcycles' speed reduction, whicharose because of continuous changes and improvements of their braking systems. This encourages forensic experts to take additional steps to obtain reliable data. Given that nowadays the market of motorcycles is represented by vehicles with both classic outdated brake system (mechanical) and modern one (hydraulic, combined, etc.), the design of these brake systems is described in detail, their comparisons are made, the advantages and disadvantages are given. There was made a conclusion about the need of supplementing and further methodological development of the statistical database of motorcycle speed-reduction parameters, taking into account the changes that have occurred in the brake systems, by conducting (if possible) their complex running tests. The reliability of the obtained results and conclusions is provided by a system of methods of scientific knowledge. These include, in particular, synthesis and analysis, including statisticalones, to improve accuracy and objectivity, and therefore the quality of expert judgment, to justify the need for complex tests to obtain the real value of the deceleration of modern motor vehicles.Keywords: forensic experts; motorcycle speed-reduction; disc brakes; hydraulic brake actuator; brake pad; overlays; ABS system.

"By wire" technology merged into multiple vehicular subsystems, including gear changing, drive, and braking systems. The brake by wire system is developed to overcome the problems associated with the integration of mechanical and hydraulic systems in novel vehicular systems. Even though brake by wire systems has potential advantages, the conventional brake systems' tactile sensation will be removed if migrated to the electrical by wire control scheme. This paper proposes a novel control mechanism that provides amplification of force, scaling of position replication, and a virtual springdamper based pedal retraction which provides bilateral brake force feedback to the driver's pedal similar to the hydraulic brake system. The proposed system performance was simulated and tested using a bilateral teleoperation system with disturbance observers (DOB) and reaction force observers (RFOB). The proposed system provides pedal force amplification and brake force feedback to the driver's pedal using RFOBs. The virtual spring retracts the brake pedal, similar to a mechanical pedal retraction system. The system simulation and experimental results provide evidence of the proposed system's force amplification, position scaling, and pedal reaction capabilities.

In order to explore the braking effect of the Anti-lock brake system (ABS) control algorithm, a joint simulation study of anti-lock brake based on Carsim and Simulink was carried out. First, use Carsim to design and build a two-axis vehicle model; then use Simulink to build a slip rate model, a hydraulic brake model and an ABS controller model, and import the non-ABS control, logic threshold control and PID control into the ABS controller; Finally, the joint simulation interface of Carsim and Simulink was connected, and the joint simulation experiment of ABS with an initial speed of 60km/h was carried out on the open road. Co-simulation results show that: (1) The car wheels without ABS control lock and rollover occurs, while the logic threshold control and PID control have no wheel lock phenomenon and can stop normally; (2) PID-controlled ABS slippage The rate overshoot, braking time and braking distance are reduced by 48%, 3.6% and 1.7% respectively compared with the logic threshold control ABS, which has a better braking effect.

With the rapid development of the aviation industry, the utilization rate of a runway is getting higher and higher, and the time that aircrafts use the runway for takeoff and landing is getting less and less. Accidents are prone to occur at this stage, so the wheel brake system that plays a key role at this stage attracts much attention. The safety of the wheel brake system is important to ensure the normal takeoff and landing of aircrafts, minimize the occurrence of brake accidents and ensure the safety of the occupants and aircrafts. However, domestic research on wheel brake system mostly focuses on system design and performance simulation. There is little research on condition monitoring and health assessment of wheel brake system, especially hydraulic brake system. Therefore, based on the analysis of the working principle and flight recording parameters of the wheel brake system, the hysteresis characteristics of the system are found for the first time. The model of the wheel brake system considering the hysteresis characteristics is constructed, a health monitoring method based on Kalman filter is established. The effectiveness of the proposed method is verified by simulation and flight record data.

In railway locomotives, vacuum brakes is using as an alternative of air brake. The vacuum pump, brake pipe is using to make vacuum. The integral arrangement of brake cylinders uses the vacuum tank to applications of the brake. Currently a lot of light duty vehicle are built with the vacuum assist the hydraulic brake system. The vacuum brake system is used to analysis the functioning in both light and heavy vehicle. The vacuum was formed from the engine and use to building the application of the brake. The systems operation are alike an air brake system. In the vacuum brake systems, the vacuum was used before compressed air which used in the air braking system. The design and modified systems include vacuum braking system.

Brake-bleeding is the process of removing air bubbles present on hydraulic brake systems. In particular, the existence of air content within the EPB caliper deteriorates bleeding performance, causing a high-level compressibility of the brake fluid. This paper presents numerical and experimental investigations of the effect of holes on brake-bleeding performance improvement for three different nut-spindle models included in the driving-part model of the EPB caliper. In the present paper, compressible brake-fluid simulations with pressure rise and drop ranging in pressure from 0 to 100 bar are modelled with a transient numerical approach utilizing a three-phase mixture model and standard k-ω turbulence model. The experimental verification of the effect of the holes with a constant 2 mm diameter, determined from the simulation results, was conducted using a standard test device at Mando Corporation. In conclusion, the experimental results prove that the effect of the holes has considerable impact on the performance improvement.

Aiming at the problem of the stability of distributed-driven electric vehicles under braking conditions and the recovery of regenerative braking energy, a novel compound brake anti-lock braking control strategy based on wheel slip rate control is proposed. This article takes distributed-driven electric vehicles as the research object. From the perspective of the single-wheel braking dynamic model of the car, the method of designing a non-linear state observer is used to observe the changing longitudinal braking force of the wheel, and then to achieve the estimation of the optimal slip rate. Using the improved adaptive sliding mode controller to achieve effective control of the optimal slip rate to improve the chattering problem of sliding mode control. According to the output of the controller, combined with the motor brake and hydraulic brake system of the car, a composite brake anti-lock control system is designed. The joint simulation is carried out in the environment of MATLAB and CARCISM. The simulation results show that the control method studied can effectively estimate and control the optimal slip rate under various complex road surfaces, and realize the safety and stability of electric vehicle brake control.

This work deals with the problem of maximizing energy recovery while optimizing braking capability of high-performance electric vehicles under given actuator constraints. A scalable, real-time capable concept using a complementary filter with an additional daisy chain for the control allocation between hydraulic brakes and electric motors is proposed. Furthermore, a model inversion approach that derives necessary battery limits while trying to decouple the wheel speed control loop from the protection loop of a modern battery management system is described. The hybrid braking control architecture is studied in simulation and validated in a prototype electric vehicle by highly dynamical driving manoeuvres.

To solve the problem of static pressure transmission performance of electronic hydraulic brake system, the mathematical models of main cylinder, solenoid valve, accumulator, and motor hydraulic pump of electronic hydraulic brake system are established. Based on the mathematical model, the static pressure transmission performance of electronic hydraulic brake system is analyzed. Then the standard normal state model of static pressure transmission performance of electronic hydraulic brake system is established by statistical method. The threshold correlation degree between the vibration signal of the static pressure drive and the normal state mode obtained by the vibration acceleration sensor are calculated. If the threshold correlation degree is greater than or equal to 0.5, the precision pressure transmission state of the electronic hydraulic brake system to be tested belongs to the standard normal state, and the threshold correlation degree is less than 0.5, indicating that the precision pressure transmission state of the electronic hydraulic brake system to be tested does not belong to the standard normal state. The test results show that the proposed method can effectively detect the boost response of the static pressure transmission of the electronic hydraulic brake system under high and low strength conditions under normal conditions and accumulator failure conditions. The method can effectively detect the static pressure transmission state of the electronic hydraulic brake system belongs to the fault state according to the threshold correlation degree, which is consistent with the simulation results.

To absorb the power generated by a free turbine, hydraulic brake systems of various designs are used in ground tests of aircraft turboshaft gas turbine engines. Ground tests of aircraft turboshaft gas turbine engines with the use of such hydraulic brakes can result in emergency modes of automated engine control in the area of operation of a free turbine speed regulator. Mismatch between the hydraulic brake loading characteristics and the loading characteristics of the rotor driven by a free turbine of the engine is the main cause of emergency operation of automated control systems.The presented experimental loading characteristics of the hydraulic brake and the helicopter rotor show their significant difference in terms of gain. To eliminate this difference, a possibility of modeling dynamic parameters of rotors by simple automation means was considered. To solve this problem, a linear dynamic model and a block diagram of an automated hydraulic brake control system for ground testing of turboshaft gas turbine engines were elaborated. The law of regulation of the hydraulic brake loading was substantiated. A structurally dynamic diagram of the developed automated control system was presented and calculation formulas for determining the regulator parameters were given. Transient characteristics of the hydraulic brake unit without automation means and with the use of an automated loading control system were calculated. The presented calculation results have shown that the use of automation make it possible to fully emulate characteristics of the helicopter rotors, Для поглощения мощности, вырабатываемой свободной турбиной, при наземных испытаниях авиационных турбовальных газотурбинных двигателей применяются гидротормозные установки различных конструкций. Наземные испытания авиационных турбовальных газотурбинных двигателей с применением таких гидротормозов могут приводить к нерасчетным режимам работы системы автоматического управления двигателем в области работы регулятора оборотов свободной турбины. Основной причиной нерасчетной работы системы автоматического управления является несоответствие загрузочных характеристик гидротормоза загрузочным характеристикам воздушного винта, приводимого во вращение свободной турбиной двигателя.Представленные экспериментальные загрузочные характеристики гидротормоза и несущего винта вертолета показывают существенное различие данных характеристик по величине коэффициента усиления. Для устранения этого различия рассматривается возможность моделирования динамических параметров несущих или гребных винтов простыми средствами автоматизации. Для решения данной задачи была разработана линейная динамическая модель и структурная схема автоматизированной системы управления гидротормозом, предназначенного для наземных испытаний турбовальных газотурбинных двигателей. Дано обоснование закона регулирования загрузкой гидротормоза. Представлена структурно-динамическая схема, разрабатываемой автоматизированной системы управления и приведены расчетные формулы для определения параметров регулятора. Выполнены расчеты переходных характеристик гидротормозной установки без средств автоматизации и с применением автоматизированной системы управления загрузкой. Представленные результаты расчетов показывают, что применение средств автоматизации позволяет полностью эмулировать характеристики несущих винтов вертолетов, Для поглинання потужності, що виробляється вільною турбіною, при наземних випробуваннях авіаційних турбовальних газотурбінних двигунів застосовуються гідрогальмові установки різних конструкцій. Наземні випробування авіаційних турбовальних газотурбінних двигунів із застосуванням таких гідрогальм можуть призводити до нерозрахованих режимам роботи системи автоматичного управління двигуном в області роботи регулятора обертів вільної турбіни. Основною причиною не розрахункової роботи системи автоматичного управління є невідповідність завантажувальних характеристик гідрогальм завантажувальним характеристикам повітряного гвинта, що приводиться в обертання вільною турбіною двигуна.Представлені експериментальні завантажувальні характеристики гідрогальма і несучого гвинта вертольоту показують суттєву різницю даних характеристик за величиною коефіцієнта посилення. Для усунення даної відмінності розглядається можливість моделювання динамічних параметрів несучих або гребних гвинтів простими засобами автоматизації. Для рішення даного завдання було розроблено лінійна математична модель та структурна схема автоматизованої системи управління гідрогальмом, призначеного для наземних випробувань турбовальних газотурбінних двигунів. Обґрунтовано закон регулювання завантаженням гідрогальма. Представлена структурно-динамічна схема автоматизованої системи управління, яка розробляється і наведені розрахункові формули для визначення параметрів регулятора. Виконано розрахунки перехідних характеристик гідрогальмової установки без засобів автоматизації та із застосуванням автоматизованої системи управління завантаженням. Результати розрахунків, що представлені, показують, що застосування засобів автоматизації дозволяє повністю емулювати характеристики несучих гвинтів вертольотів

The brake system is a device to slow down or stop the movement of the wheel automatically so that the vehicle will move slowly. This completeness in the vehicle is very important and vital because it functions as a safety for life in driving. In the process of making the Electric Car Fusena brake system has steps in the process, consists of size planning, materials used, designs realized, manufacturing brake system supporting components, assembly, installation and testing of brake systems. The Fusena Electric Car brake system use a disc-type hydraulic brake system with one brake master that can work simultaneous with dual circuit fluids (front and rear braking). The comparison of the brake pedal is changed to 3: 1, designing and recreating the caliper stand to make it more precise so that it gets maximum brake performance and is better than the system used before. Static testing of the Fusena Electric Car hydraulic brake system is done by positioning the vehicle on an inclined plane at a slope of 15 and 20 with a variable driver load of 40 kg, 50 kg, 60 kg and 70 kg. The test results are that the vehicle does not experience displacement or movement. And the results of the average dynamic test of the Brake System at a speed of 27.3 km/h with an average braking distance of 171 cm = 1.71 meters and the average deceleration time is 0.26 seconds.

This paper presents a control method of an antilock brake system (ABS) for electric vehicles. For decades, serious efforts have been dedicated to designing a wheel slip-based ABS controller, but there are some inherent flaws. To realize a robust control system, the wheel slip and road friction information are generally required. Unfortunately, however, these parameters cannot be accurately measured in production vehicles. The method suggested in this paper is aimed at solving these problems by exploiting the nonlinear characteristics of tire force. The optimal wheel slip can thereby be found without wheel slip and road friction information. We employ the motor as an actuator instead of a conventional hydraulic brake system at the front wheels. However, the rear wheels are still hydraulically controlled. That is, the front and rear wheels have different roles in the proposed method. This hardware configuration can be changed for control purposes, so the proposed approach is not designed for a specific hardware configuration. The performance of the proposed method is confirmed by simulations and real vehicle-based experiments.

This study deals with the development of drum brake liner for a multi-utility vehicle possessing a hydraulic brake system by varying 7 weight % of steel fiber and stainless steel fiber each, in friction composite formulations. The developed friction composites were tested for physical, chemical, corrosion, mechanical, thermal properties, and tribological characteristics, under near-actual conditions using an inertia dynamometer as per industrial standards. Finite element analysis software (ANSYS) analysis was performed to show the thermal stress distribution of the developed friction composites at the maximum temperature rise due to heat generated during brake stops, and an extensive evaluation method was used to rank the composites. The study concludes that the brake factor of the stainless steel fiber-based friction composite produces stable performance in all conditions with a lower liner temperature rise of 340 °C and lower thermal stress at 4.255294 MPa. However, the steel fiber-based composites produced high performance at the beginning but deteriorated after a certain period due to higher levels of corrosion and a high temperature rise of 361 °C resulting in a negative fade (−0.84%) and more thermal stress (5.619102 MPa). The primary plateau, secondary plateau, back transfer of drum wear debris, and the distribution of constituents on the worn surface of the developed composites in a resin matrix were identified and studied using a scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy.

Hybrid electric vehicles (HEVs) equipped with dual clutch transmission (DCT) can benefit from engine auxiliary braking force and driving motor regenerative braking force in braking conditions. This can effectively reduce the workload of hydraulic mechanical braking systems and recovery braking energy, which will improve the fuel economy. In the downshift process, the driving motor is involved to response the change of torque/speed demand, which can further improve the shift quality of DCT without affecting the engine emissions and fuel economy. The combined braking condition of HEVs with DCT allows for the variation of power distribution between the front and rear axle, as well as the electric and hydraulic braking force. In this study, the downshift decision strategy is designed based on the two-parameter shift schedule, while considering the driver’s subjective driving intention. Subsequently, the mathematical model developed to investigate the downshift process of HEVs with dual clutch transmission has been applied to skip downshift process, to analyze the control sequence and implement different control algorithms according to respective control objects. Specifically, the sliding mode variable structure optimization control algorithm is used to allow the engine speed to track the target value in the torque phase. In addition, the linear quadratic tracking controller and the model reference adaptive system are used, based on adjustable parameters, to realize the speed synchronization of the clutch driving and driven plate in the inertial phase. According to the results of electro-hydraulic braking force distribution, the braking forces of an integrated starter generator (ISG) motor and hydraulic brake system are controlled to switch to the demand level. Then, the simulation model established on a Matlab/Simulink platform is used to validate the skip downshift control strategy. Finally, the designed control strategies are verified on the test bench. The test results demonstrate that the established shift control strategy can achieve the target power downshift under braking conditions, and have a good downshift quality, which lays a foundation for subsequent development and real vehicle tests.

Wheel braking devices is some of the most widely used landing deceleration devices in modern aircraft. Jet pipe pressure servo valves are widely used in large aircraft wheel brake control systems because of their high anti-pollution ability, high sensitivity and fast dynamic response. However, most brake systems suffer vibration phenomena during the braking process. The pressure servo valve is an important part of the hydraulic brake system, and also an important factor affecting the vibration of the system. In order to solve the vibration problem in the brake system this paper present a two-stage brake pressure servo valve design. We place feedback channels at both ends of the main spool to stabilize the output pressure. In addition, modeling, simulation and experimental verifications are carried out. Firstly, the principle and structure of the pressure servo valve are described. An accurate mathematical model of the two-stage brake pressure servo valve and the testing system is established. Then a simulation analysis is carried out. Finally, a two-stage brake pressure servo valve testing experimental platform system is built for experimental verification. The experimental results show that the mathematical model of the two-stage brake pressure servo valve and the test system established in this paper have high accuracy, and the designed servo valve structure can restrain vibrations. The above research results provide a useful theoretical reference for performance optimization, stability analysis and valve body structure improvement of brake pressure servo valves.

Nowadays, autonomous vehicles are increasing, and the driving scenario that includes both autonomous and human-driven vehicles is a fact. Knowing the driving styles of drivers in the process of automating vehicles is interest in order to make driving as natural as possible. To this end, this article presents a first approach to the design of a controller for the braking system capable of imitating the different manoeuvres that any driver performs while driving. With this aim, different experimental tests have been carried out with a vehicle instrumented with sensors capable of providing real-time information related to the braking system. The experimental tests consist of reproducing a series of braking manoeuvres at different speeds on a flat floor track following a straight path. The tests distinguish between three types of braking manoeuvre: maintained, progressive and emergency braking, which cover all the driving circumstances in which the braking system may intervene. This article presents an innovative approach to characterise braking types thanks to the methodology of analysing the data obtained by sensors during experimental tests. The characterisation of braking types makes it possible to dynamically classify three driving styles: cautious, normal and aggressive. The proposed classifications allow it possible to identify the driving styles on the basis of the pressure in the hydraulic brake circuit, the force exerted by the driver on the brake pedal, the longitudinal deceleration and the braking power, knowing in all cases the speed of the vehicle. The experiments are limited by the fact that there are no other vehicles, obstacles, etc. in the vehicle’s environment, but in this article the focus is exclusively on characterising a driver with methods that use the vehicle’s dynamic responses measured by on-board sensors. The results of this study can be used to define the driving style of an autonomous vehicle.

Electric vehicles are spreading in automotive industry pushed by the need of reducing greenhouse gas. However, the use of multiple electric motors, i.e., one per wheel, allows to redefine the vehicle powertrain layout with great benefits on vehicle dynamics. Electric motors braking torque is in general not enough to produce high decelerations. Hydraulic friction brakes are still necessary for safety reasons and to avoid oversized motors. This paper presents a control strategy for distributed electric motors (EM), one per wheel, to maximize the regenerative braking. The controller handles cooperative braking among EMs and hydraulic brakes, which are still necessary to guarantee top braking performance of the car. The proposed algorithm considers the driver requested braking torque as well as the required yaw moment by stability control system. Motor efficiency map and wheel normal load are considered to optimally distribute the torques. With respect to conventional distribution strategies, the presented algorithm improves performance, maximizing the regenerative braking power.

One of the most necessary systems of a vehicle is its braking system. It de-accelerates a moving vehicle by transforming its kinetic energy into heat energy and sound energy by modes of friction between components. Since it is a system, it consists of a number of parts which are inside as well as outside the cabin of that vehicle. Braking system is an assembly of many parts working together to retard of control vehicle intentionally or in some unwanted emergency condition. These parts are brake pedal, vacuum booster, master cylinder, brake lines (both metallic and non-metallic), brake caliper, brake pads, disk rotors and brake fluid (in hydraulic brakes). Only brake pedal is the part of braking system which is inside driver’s cabin and by which brakes can be employed in real time of performance. It works like any of three classes of lever, which consists of load, effort and fulcrum. It transfers the force from driver’s lower limbs to the hydraulic fluid inside master cylinder, through a plunger attached to piston. Sometime, the force applied by driver’s feet is not enough to slow large vehicles such as trucks and land movers. Therefore, a proportion (leverage) or a vacuum booster or both are taken into account. This magnifies the force applied by driver many times, by which a large pressure is created inside the master cylinder which is conveyed by brake fluid to the caliper. This pressurized brake fluid when comes in contact with the piston of caliper creates an axial force that depends on the surface area of the piston of brake caliper. The pressure of the brake fluid pushes the caliper piston outwards by which is in contact with the brake pads that grasp the disk rotor and slow down or stop the vehicle according to the driver’s requirement. Therefore, the movement of the brake pedal should be enough and must be comfortable for driver which will push the piston outside to an optimum length to retard the motion of vehicle.