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The object of the research is the electro-hydraulic executive modules (drives) of the exoskeleton of the lower extremities with a rigid structure of the power frame. The problem of schematic and parametric execution of modules located in the linkage joints of the exoskeleton which is used for verticalization of patients is considered. The aim of the study is to estimates energy consumption, sensitivity, establish a rational structure and parameters of modules that provide programmed movement according to the criterion of energy sufficiency. The laws of motion and diagrams of loads required for lifting a patient from a sitting position are presented.

Wear caused by contaminated oil or frequent reciprocating of the spool is the chief source of internal leakage in electro-hydraulic directional valves. It is difficult to detect the location and extent of the internal wear of directional valves because the hydraulic transmission works in a closed system. Therefore, this paper focuses on the internal leakage fault diagnosis caused by the wear based on intrinsic mode functions (IMFs) and weighted densely connected convolutional networks (WDenseNets), especially for electro-hydraulic directional valves. First, the empirical mode decomposition is performed in three subsections, respectively, and a series of IMF components are obtained correspondingly. Combined with the ReliefF feature selection algorithm, the optimal IMF component is selected. The weights assigned to the optimal IMF mode are normalized and then weighted as the subsequent diagnostic feature vector. Then, a WDenseNet inspired by squeeze-and-excitation networks is designed. Finally, the weighted optimal IMF component is used as the input for the WDenseNet for fault identification and classification. In addition, an experimental method to investigate the internal leakage faults associated with wear is developed. Theoretical and experimental results indicate that the fault diagnosis method can be used to identify the type of internal leakage and wear location in electro-hydraulic directional valves. Compared with other intelligent diagnosis methods, this method has higher diagnostic accuracy and better training stability. The effectiveness of the proposed method is also verified through an experimental study of the bearing fault in an axial piston pump.

In order to test the performance of the LVIB-15 self-propelled light electro-hydraulic servo vibrator developed by Jilin University, a comparative test was conducted on different excitation conditions of a hard pavement and sandy road in Chaganhua town, Jilin Province, China. The optimum scanning frequency was determined by comparing different scanning frequencies. And seismic exploration with a length of 1.2 km was completed. The results show that the reflections were very clear and had good consistency. The signal-to-noise ratio of seismic signal was very high, reaching a reflector of 1400 ms, proving that the seismic data of vibroseis had high accuracy and reliable results and it meets the demand of geophysical prospecting.

Considering the high power density and high recovery efficiency of the hydraulic energy storage system, the power system combined with the hydraulic pump is adopted. The matching of automobile power transmission system includes the matching of hydraulic pump parameters, hydraulic accumulator parameters, motor parameters and battery parameters. AMESim and Simulink were used to carry out simulation modeling to analyze its performance. The simulation results showed that the adaptive combination of hydraulic system and battery system in electro-hydraulic hybrid vehicle could effectively improve the economic performance of the vehicle while ensuring the dynamic performance of the vehicle. It puts forward more efficient technology concept for the future development of hybrid electric vehicle.

In view of the complex terrain, low level of mechanization and intelligence in hilly region, a human-computer interaction system was designed for electro-hydraulic hitch control system of tractors in hilly region. According to the actual functional requirements of electro-hydraulic hitch control system of tractors in hilly areas, human-computer interaction interface was designed in flash environment, and CAN communication module in Human-computer interaction system was designed in Flash Develop environment. Finally, a hardware test platform of the human-computer interaction system was built in the room for laboratory tests. The results showed that the human-computer interaction system can meet the working requirements of the electro-hydraulic hitch control system of tractors in hilly areas.

An adaptive control system with good following characteristics is designed for the electro-hydraulic servo system which are strongly coupled and seriously nonlinear. The model of position servo system on air rudder is discussed with the uncertain system equivalent to the one with parametric variable double input and single output to establish a Popov-MRAC (Model Reference Adaptive Control) system. The simulation results show that the Popov MRAC system has good following characteristics, precision and robustness.

Taking the large cross-section return air roadway of 4201 working face in No.2 panel of Liuzhuang Coal Mine as engineering background, the engineering geological conditions and supporting conditions of roadway were analyzed, and the 3×ZQL2×5200/23/45WD split advanced support was used to support the roadway in the advance support area. On this basis, the design schemes of support pressure monitoring system, automatic deviation adjustment system, environmental monitoring system, remote control system and software control system were analyzed, the subsystems with different functions constitute the electro-hydraulic control system of advanced support. The advanced support has good application effect and can meet the requirements of advanced support and automation control of large cross-section roadway.

Aiming at the problems of manual laying of tracks, sliding car and dropping lanes in the process of traditional train transportation of winch traction equipment, this paper presents a long-distance self-moving equipment train, which is powered by hydraulic pressure, self-contained track, highly integrated train self-moving, walking deviation, anti-dropping and other functions, so as to realize the striding forward movement of the whole equipment train driven by the traction device. Innovative adopt of loop liquid supply, multiple group remote control and other technologies, and using multi-master control, and high reliability, strong anti-interference CAN (Controller Area Network) fieldbus real-time control network, it ensures the synchronous and smooth lifting of the train, and it moves forward with the self-moving traction device. Thereby, the automatic system development and demonstration application of the fully mechanized mining equipment can be realized.

In order to solve the steady-state error in position tracking control for electro-hydraulic servo universal testing machine, caused by uncertain parameters in the system model, an adaptive sliding mode control strategy based on RBF neural network is proposed for this situation. This paper utilizes the adaptive ability of RBF neural network to improve the control quality of the electro-hydraulic position servo system. The strategy has three parts: the equivalent control, the reaching law control and the compensation control based on RBF network. Simulations verify that the control system can track the reference curve well with unknown parameters.

The task of a relay-linear control algorithm for an electro-hydraulic servo drive (EHSD) was considered. This algorithm provides reconfiguration of the state components feedback coefficients at the very initial stage of the control object movement, when the optimized control action does not depend on these coefficients. A FESTO hydraulic learning system combined with Matlab+Simulink Desktop Real Time was used for realization of the developed algorithm. Experimental results are included.

Relevance of developing the equipment for electro-hydraulic treatment of water and its solutions was substantiated. The device that is one of the electro-hydraulic spark gap installation components has been developed in order to eliminate the drawbacks of similar devices used. The application field of the device for electro-hydraulic treatment of solutions is crop production in agriculture. Electro-hydraulic treatment can be used to produce fertilizers in conditions of irrigation of greenhouse vegetable crops in personal subsidiary and peasant (farmer) farms. The installation, in addition to the cylindrical tank, contains a voltage source, a high-voltage transformer, an autotransformer, energy storage devices, rectifying cells, start-control devices and means of control and measuring. Electrodes are installed in this device, one of which has a technical scientific novelty. The tip of the negative electrode is hemispherical, which allows increasing the stored energy in the capacitor, to increase it in the discharge channel, increasing the length of the spark discharge in the liquid. The model of the device has been developed in order to substantiate the design parameters and operation modes. The developed electric diagram required for installation, runup and control of technological modes of electro-hydraulic impact on liquid media is shown. Actual model of the device is presented in photo content. The perspectivity of studying the electro-hydraulic effect is determined.

The article discusses the urgent problem associated with the creation of technology for designing the supports of the electro-hydraulic system of the Russian model of an underwater manifold under conditions of import substitution in the country’s oil and gas sector. Trends and prospects for the development of mechanical engineering for underwater hydrocarbon production are shown. Based on the initial data for the design for the calculated and simulated pipelines of small diameter, which are part of the electro-hydraulic circuit of the manifold, the corresponding supports have been developed. After developing the technologies on the prototype, it is planned to further use the developed supports as part of the serial delivery of components of the subsea production system for deep-sea oil and gas condensate fields in the Arctic region of the Russian Federation.

The present paper presents an optimally tuned proportional integral differential (PID) system which calculates the driving signal for the switching valves in order to achieve steering trajectory tracking. The designed cascade control algorithm consists of three PID controllers respectively for the spool valve position, for the effective flow rate and for the steering cylinder position. The stages of the cascade control algorithm synthesis are presented. The goals of control algorithm are to achieve fast transients with minimal overshot and steady state error. Controllers’ are tuned consequently by starting from the innermost loop based on an identified single-input multiple output (SIMO) model of the steering system by optimization algorithm with a quadratic cost. After one of the controllers is successfully tuned the model of the corresponding closed loop system is approximated and employed in the optimization procedure for the next control loop from the cascade system. The developed control algorithm is programmed into a specialized vehicle microcontroller and tested on a steering system test bench in the laboratory.

The main objective of the research is to assess the possibility of using control systems of electro-hydraulic shield supports for researching geomechanical processes in the rock massif. The research aims to increase the efficiency of longwall mining technology. As a result of the research, changes of pressure distribution in the hydraulic powered shield supports along the width and length of the longwall panel are established. Pressure changes at various speeds of a longwall advance have been established. Recommendations about an increase in efficiency of underground mining of coal seams are made. The paper novelty consists in establishment of dependences of the maximum loads upon a shield on the speed of the longwall advance.

In general, an advanced control strategy is necessary for electro-hydraulic servo system to obtain fast and accurate system response. A novel control scheme called PID sliding mode control was proposed by combining conventional sliding mode control and PID control strategy. The linear dynamic mode of electro-hydraulic servo system was established precisely. The PID sliding mode control law was deduced in detail. The chattering problem caused by original sliding mode control was weakened by a continuous PID algorithm. The simulation results of electro-hydraulic servo system demonstrated the effectiveness of the proposed method.

In order to reveal the friction and wear properties of the high-pressure axial piston pump sliding shoe, the paper designed the electro-hydraulic control platform for the performance test of the sliding shoe according to the requirements of the side structure and performance testing of the shoe. This platform includes the hydraulic system design and circuit control system development. The simulation results show that the hydraulic system is simulated by AMESim, and the open and closed loop comparison curves are obtained. Based on the PLC language platform, the circuit control program is written, which can make the electro-hydraulic control platform improve the test results of the slipper pair friction performance. At the same time, this platform also provides a solid hardware support for the study of the friction performance of the slipper pair.

The soil condition and condition of the plow affect the tillage resistance and the maximum traction of tractor. In order to improve the adaptability of tractor tillage depth control, a multi-parameter control strategy is proposed that included tillage depth target, draft force aim and draft–position mixed ratio. In the strategy, the resistance coefficient was used to adjust the draft force target. Then, based on a JINMA1204 tractor, the electro-hydraulic hitch prototype is constructed that could set control parameters.. The fuzzy controller of draft–position mixed control is designed. After that, in-field experiments of position control was carried on, and the result of experiment shows the error of tillage depth was less than ±20mm. The experiment of draft-position control shown that the draft force and the tillage depth could be adjust by multi-parameter such as tillage depth, resistance coefficient and draft-position mixed coefficient. So that, the multi-parameter control strategy could improve the adaptability of tillage depth control in various soils and plow condition.

The condition of the hydraulic excavator is complicated and the working environment is bad. The safety and stability of the control system is influenced by the external factors. This paper selects hydraulic excavator electro-hydraulic servo system as the research object. A mathematical model and simulation model using AMESIM of servo system is established. Then the pressure and flow characteristics are analyzed. The design and optimization of electro-hydraulic servo system and its application in engineering machinery is provided.

Much effort has been devoted to developing variable stiffness and variable damping devices for semi-active structural vibration control. However, little research has been done for variable inertial mass mainly caused by the mechanical terminal limit of the mass component. Based on the two-terminal mass scheme, we propose an electro-hydraulic approach to realizing a novel device with variable two-terminal mass. In this study, the flywheel that is traditionally handled by one physical terminal is manipulated by two terminals of a hydraulic cylinder-control-motor system. The transmission ratio of the system is adjusted using an electro-hydraulic proportional valve. Through modeling the ideal dynamic behavior, it is confirmed that the equivalent inertial mass between two terminals of the component can be made variable. To further understand its mechanical characteristics, a prototype device is developed and tested on a test rig. Triangular and sinusoidal excitation signals are employed respectively to identify the model parameters. The results show that the proposed model can describe the dynamic characteristics of the variable two-terminal mass device well. The proposed design and modeling schemes pave the way towards the semi-active variable inertial mass control of vibration systems.