Valve Control System Research Articles

Variable Universe Fuzzy Controller for an Independent Metering System of Construction Machinery

As a new type of hydraulic system, the independent valve control system (IMCS) has higher flexibility compared with the traditional four-side slide valve control system. The independent metering control system (IMCS) is divided into four quadrant modes, based on the speed and load of the actuator. The traditional control methods always use a discrete control strategy to realize the switching between different modes based on mode recognition. However, the spool signals frequently switch, and the actuator operating pressure and speed are not stable when the IMCS is switched between different modes. To solve the above problems, this paper proposes a continuous control strategy for the IMCS. Based on the fuzzy control principle, the variable universe fuzzy controller (VUFC) was designed. The controller contains 49 fuzzy rules, and the output of the controller at any time is calculated by the weighted sum of several fuzzy rules. The VUFC divides the system into 49 rules, which are activated by multiple modes at any time to achieve a smooth transition between different modes. The VUFC was verified in a 37 ton excavator model and compared with the traditional independent metering meter-out (IM_MO) control strategy. The results showed that the VUFC significantly improved the frequent switching of the spool signals, and the running speed and pressure stability of the hydraulic cylinder were significantly improved. At the same time, the response speed of the hydraulic cylinder became faster at the start of the system. The VUFC can realize the continuous control of the IMCS and improve the operating performance of excavators.

PLC Modification of Lubrication System for Mining Dump Trucks

The automatic lubrication system of the mining dump truck is provided with pressure by a hydraulic gear pump. The pressure sensor provides real-time working pressure feedback for the lubrication system, serving as a basis for the electromagnetic pressure relief valve control system. The lubrication condition of the articulated bearings in the mining dump truck has a significant impact on the truck's utilization rate. Proper lubrication is directly related to extending equipment lifespan and reducing equipment maintenance costs. By researching and analyzing the principles of the automatic lubrication control system for mining dump trucks, and considering the characteristics, types, and maintenance difficulties of lubrication system failures, we propose a PLC modification to the original control system. This modification aims to enhance system operational stability and reduce maintenance costs.

Analysis of Power Failure Causes and Optimization Strategy of Valve Control System in Flexible DC Transmission Project

Kunliulong DC project is the first UHV hybrid multi-terminal DC project in the world. The reliability of its valve control system is directly related to the operation stability of the DC project. This paper analyzes the DC trip event caused by the power failure of the pulse box of the valve control system, determines the root cause of the event, proposes the rectification measures based on the accident causes, and carries out the test verification. The proposed scheme has been successfully applied to the Longmen converter station of the Kunming Liulong Project. The conclusions and measures in this paper have important reference significance for the design of the valve control system of flexible and direct engineering and for guiding the engineering practice.

Analysis of Frequency Adjustable Control of Permanent Magnet Synchronous Motor for Pump-controlled Actuators

Recently the pump-controlled system has actively been proposed as a replacement for conventional valve-controlled systems, to improve the energy efficiency in non-road mobile machinery. Earlier research demonstrated that a pump-controlled hydraulic system combines the best properties of traditional hydraulics and electric intelligence. This pump-controlled system can be realized via direct control of hydraulic pimp/motor by varying speed of electric motor without complex servo valves. Nowadays, a wide range of different electric motors is known and available with efficiency higher than 95% One of the most attractive option of electric motor is Permanent Magnet Synchronous Motor (PMSM) due to its size, power, and high efficiency.
 However, control of electric motors in pump-controlled systems has are not yet considered and not well researched.
 In this paper, the main objective of this investigation is determination of control values for the pump-controlled actuator and analysis of system’s behavior in different applications.
 Therefore, model of PMSM drive with pump-emulated load is proposed. Field Oriented Control (FOC) gives wide range of the speed regulation and smooth characteristics, but tuning of controllers is challenging.
 Case of the steering-modeled load represented that such operations need more power than other modes. More complex frequency converters allow to reach higher level of accuracy and decrease torque ripples, but complexity of such systems increases rapidly.

Saving energy with timers

In this study, it is aimed to save energy by placing timers in public offices and private workplaces for heating residential units with geothermal energy outside working hours and on holidays. For this, proportional valve control system design and application has been carried out. Proportional valve is connected to the heat exchanger return. The control form of the floating type proportional valve is on-off, the control of the proportional valve with analog input is applied in the form of PI control. It is realized by programming smart relays in both controls. PT100 was used to measure the heat exchanger inlet, return and temperature values entering the building.
 As a result of this study, the heat exchanger return temperature was adjusted to the temperature at which the buildings would not cool completely on holidays and after working hours, allowing more buildings to be heated with the energy saved.

Operator actions evaluation for MSGTR accident mitigation

The safety assessment of nuclear power plants for multiple failure accidents such as Multiple Steam Generator Tube Rupture (MSGTR) and the verification of the suitability of accident management measures have gained prominence in the nuclear engineering field after the Fukushima accident. Compared to Steam Generator Tube Rupture (SGTR), the MSGTR accident progresses rapidly due to the high break flow rate, and thus appropriate operator actions are essential to prevent the release of radioactive materials into the environment. It is crucial for the operators to identify the MSGTR early and perform each operator action within the allotted time in order to mitigate the accident successfully. In this study, a reference analysis model for MSGTR is developed, differences from SGTR are analyzed, and the required time for major operator actions are derived through various sensitivity analyses. In conclusion, the operator can confirm that there is a high possibility of MSGTR occurring through the changes in the subcooling degree at the hot-leg and the Pressurizer (PZR) water level. The appropriate time to be initiated for major operator actions are as follows: (1) Reactor Coolant Pump (RCP) manual trip within 10 min after the reactor trip, (2) Reactor Coolant System (RCS) temporary-cooldown operation through Main Steam Isolation Bypass Valve (MSIBV) and Steam Bypass Control System (SBCS) within 15 min after the reactor trip, (3) PZR spray operation – RCS temporary-cooldown operation in progress, and (4) RCS controlled-cooldown operation using Atmospheric Dump Valve (ADV) within 15 min after the end of the RCS temporary-cooldown operation. Additional possible action is the restart of RCP, but the execution of this action depends on the operator’s judgment. The results of this investigation have significant implications which can be utilized for improving the accident mitigation strategies and the operator training for MSGTR.

A INVESTIGATION OF EFFICIENCY OF SERVO MOTOR DRIVE HYBRID PRESS BRAKE SYSTEM: A COMPARATIVE STUDY WITH A TRADITIONAL APPLICATION

In this study, an experimental investigation of the conventional valve-controlled and variable speed pump-controlled control of the press brake system with two hydraulic double-acting actuators was carried out. The system envisaged on the 80-ton press brake, which is one of the press machines in which hydraulic systems are widely used, has been applied. In conventional valve-controlled systems, the flow rate in the system is adjusted with the help of a proportional valve, while the required flow in the variable-speed pump-controlled system is provided by changing the pump speed with the help of a servo motor. From the results obtained, it has been seen that 54% energy saving can be achieved in 100 cycles. The amount of oil used has also been reduced.

Simulation and Experimental Study of the Characteristic Parameters of an Aircraft Cabin Temperature Control Valve

The temperature control valve system is essential to an aircraft. This study proposes a temperature control valve system in which the cold and hot gas exchange heat through the heat exchanger without mixing to cool the hot gas. The purpose is to maintain the stability of gas flow and temperature at the outlet of the hot path. First, a mathematical model of the temperature control valve is established, and the feasibility of the method is theoretically analyzed. After that, the temperature control valve model is meshed in Ansys, finite element analysis is performed, and the factors that may affect the outlet temperature of the hot path are qualitatively analyzed. A characteristics test experiment for the designed temperature control valve is compared with simulation results to verify the system’s feasibility. A steady-state model of the heat exchanger was obtained by a 25-point orthogonal experiment. Taking the predicted hot-side flow rate of the heat exchanger under different flow conditions as input, the heat exchanger model was fitted and dynamically analyzed, which confirmed the feasibility of PID adaptive control of the temperature control system.

Research on Flexible HVDC Converter Valve and VBC Redundancy Reliability Improvement

Flexible HVDC transmission play an important role in building a strong smart grid, and it is also very important to design a reliable redundant system for the converter valves and the valve-base controller (VBC). In order to improve the redundancy of the current valve control system, firstly, this paper proposed a new redundant configuration scheme for flexible HVDC converter valve and VBC. Secondly, this paper proposed a switching logic and switching time sequence for the redundant link, in order to make all VBC board hot-swappable when the HVDC system is in operation. Finally, depend on the “Baihetan-Jiangsu” HVDC project, the RTLAB-based test platform was established, which verified the correctness of the redundant system design. The test result shows that the designed scheme improves the redundant system reliability of the flexible HVDC system, and has well-referenced value.

Design of FOPID Controller for Pneumatic Control Valve Based on Improved BBO Algorithm.

Aiming at the problems of nonlinearity and inaccuracy in the model of the pneumatic control valve position in the industrial control process, a valve position control method based on a fractional-order PID controller is proposed. The working principle of the pneumatic control valve is analyzed, and its mathematical model is established. In order to improve the accuracy of the model, an improved biogeography-based optimization algorithm is proposed to tune the parameters of the fractional-order PID controller in view of the wide range and high complexity of the fractional-order PID controller. The initialization of the chaotic graph, the adjustment of the migration model, and the improvement of the migration operator and the mutation operator are introduced to improve the algorithm optimization ability, which is used for the model identification of the control valve control system. The simulation and experimental results clearly show that, compared with the integer-order PID controller, the designed fractional-order PID controller has faster response speed and control accuracy, which can better meet the requirements of pneumatic control valve position control.

Dynamic Response Analysis of Control Loops in an Electro-Hydraulic Servo Pump Control System

An electro-hydraulic servo pump control system realizes the basic action of a hydraulic cylinder by controlling the servo motor, which effectively improves the problems of a traditional valve control system such as high energy consumption, low power-to-weight ratio, and poor anti-pollution ability. However, the static accuracy and dynamic performance of an electro-hydraulic servo pump control system are limited due to the electro-hydraulic coupling and flow nonlinearity. Based on this, in this paper, we establish a mathematical model of an electro-hydraulic servo pump control system. Starting from the internal control mechanism of the system, the Simulink simulation model is established to analyze the dynamic response of the system current loop, speed loop, position loop, and pressure loop. The system parameters are obtained by combining the system dynamic analysis and component technology samples. The position/force control model of the electro-hydraulic servo pump control system is built for simulation, and the experimental platform is built for experimental verification. The results show that the system position/force control can achieve good dynamic response and steady-state accuracy after the parameters are determined based on the dynamic analysis of control loops.

Research on Safety Interlock System Design and Control Experiment of Combined Support and Anchor Equipment.

In view of the risk of collision with humans or equipment arising from a lack of protection in the operation process of combined support and anchor equipment on the heading face, this paper designs a safety interlock system for combined support and anchor equipment. Firstly, a mathematical model of hydraulic power system control and a valve control system based on feedforward–feedback optimization were established according to the power demand of the combined support and anchor equipment. Secondly, according to the reliability indexes of the safety interlock system, corresponding sensor, logic control and execution modules were designed. Ultrasonic sensor groups were arranged at the key positions of the combined support and anchor equipment to capture the position information in real time when the equipment was moving. Thus, the pump-valve hydraulic system was controlled through closed-loop feedback. The experimental results show that the safety interlock system of the combined support and anchor equipment can adjust the revolving speed of the permanent magnet synchronous motor (PMSM) in real time according to the distance from the obstacle, so as to control the pump outlet flow, and then perform interlocking safety control of the hydraulic cylinder’s movement speed. The system can effectively prevent damage to the surrounding equipment or personnel arising from equipment malfunction.

GAS ELECTRIC VALVE DESIGN

In this era of globalization, science and technology has developed rapidly, especially in the industrial world. As for science and technology that is beneficial to industry, namely for components of the production process, one of which is Valve control. This technology is used to modify the fluid flow or pressure rate in a process system by using power for its operation. The application of this control valve is used to control a pressure rate or quantity, such as the amount of oxygen gas content (O₂) and carbon dioxide (CO₂) in fruit and vegetable plants. In the research that has been carried out on the carbon dioxide (CO₂) process using a porous fiber membrane contactor, the gas model is absorbed in a pure state at cold room temperature. In this study, it is still an obstacle when applied in the field because there are many factors that have not been taken into account, so in an effort to control the wasted gas, an electric gas valve control system device is needed which is designed to determine the value of wasted gas. This system is designed with valve components, servo motors, solenoid valves, Arduino uno, and relays, where all these components are built and programmed with Arduino uno microcontroller. The results of the test are carried out to determine the level of accuracy of each input to the control valve and to determine the value of the gas wasted at the degree of opening of the valve. The test results on the ten forms of angular movement are when the valve works and opens at a movement angle of 0° to the movement, the valve opens at 0%. When the valve works and opens at an angle of movement of 10° to rotation, the valve opens by 11.1%, and when the valve works and opens at an angle of movement of 20° to 80° to the movement, the valve opens by 22.2% to by 88.8%, then when the valve works and opens at an angle of movement of 90° to the movement, the valve opens by 100% or fully opens. The benefits of this research in the performance process of production technology in industry are to meet consumer demand by producing safe, minimally processed, additive-free, and stable quality food.

(Invited, Digital Presentation) Ultrathin Lateral Heterostructures Based on Two-Dimensional Semiconductors

Low-dimensional (2D) materials, including carbon nanotubes, graphene, boron nitrides, and transition metal dichalcogenides (TMDs), have provided a platform to explore novel physics at the nano-scale. In addition to the fascinating properties of low-dimensional materials themselves, they allow exploring novel superstructures, such as heterojunctions, heterostacks, and superlattices, which give even broader possibilities. We are working on low-dimensional superstructures fabricated by (1) crystal growth with metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), and (2) stacking each component with the full-dry-transfer-based manipulation technique[1]-[6]. This presentation will focus on our recent works on low-dimensional superstructures, such as 2D ultrathin lateral superlattices. For example, we have successfully realized MoS2/WS2 2D lateral superlattices with a periodicity of down to one-atom-thick by MOCVD with an automatic valve control system. Also, we have observed characteristic PL arising probably from 1D junction structures. More details on the fabrication and optical properties of these superstructures will be addressed in this talk.[1] Y. Murai, et. al., ACS Nano 2021, doi.org/10.1021/ascnano.1c04584 [2] T. Hotta, et. al., ACS Nano 2021, 51:1370-1377.[3] T. Hotta, et al., Phys. Rev. B 2020, 102:115424.[4] S. Zhao et al., Phys. Rev. Lett. 2020, 124:106101.[5] Y. Uchiyama et. al., npj 2D Mater. App. 2019, 3:26.[6] M. Okada, et. al., ACS Nano 2018, 12:2498-2505.

Family Business Corporate Governance: A Case Study of PT. Puco

This study is about the family business and its relation to governance in the family business, namely at PT. Puco. PT. Puco is a valve control system manufacturer in Indonesia. This research aims to identify the picture of governance in PT. Puco recommends key factors determining the success of governance at PT. Puco and create an ideal governance concept for PT. Puco. The research method used is qualitative research with data collection methods using interviews, Analytical Hierarchy Process, and the Soft System Methodology approach. The results of the research on governance description is PT. Puco has implemented governance following the ISO 9001:2015 standard but needs improvement. The research results on the key factors determining the success of governance at PT. Puco. The results propose governance model for PT. Puco consists of family and business circles. Proposed changes to resolve the problem need to be taken as an action to improve the situation.

Exploring the Essence of Servo Pump Control

The electrohydraulic servo variable speed volume pump control system (hereinafter referred to as ESPCS) is integrated with a permanent magnet synchronous motor (hereinafter referred to as servo motor), a fixed-displacement pump, and a hydraulic cylinder. By controlling the servo motor speed, the output flow of the system can be controlled, as can the displacement, force, and speed of the hydraulic cylinder. Compared with the traditional electro-hydraulic servo valve control system, the ESPCS has the advantages of high power-to-weight ratio, energy saving, and environmental friendliness. However, due to the extremely nonlinear flow output of the ESPCS, further improvement of system control performance is greatly hindered. This paper focuses on the nonlinear characteristics of servo motor, fixed-displacement pump, hydraulic cylinder, and other key components in the system. A compensation method based on nonlinear characteristic mapping is proposed. Compared with the traditional PID control method (pressure control accuracy ± 0.12 MPa), the pressure control accuracy of the system is greatly improved (pressure control accuracy ± 0.037 MPa), which opens up a new way to improve the pressure control accuracy of the ESPCS.

Switching characteristics of a high-speed rotary valve for switched inertance hydraulic converters

The switched inertance hydraulic converter is a sub-domain of digital hydraulics which relies on digital switching to adjust pressure or flow instead of the dissipation of power by throttling, providing an energy-efficient alternative to conventional proportional or servo valve-controlled systems. The high-speed switching valve is a key component to realise the digital switching and its switching characteristics has significant effects on the performance of switched inertance hydraulic converters. In this article, the switching characteristics of a high-speed rotary valve are investigated. The switching orifice area of the valve is calculated based on the movement of the valve components with a consideration of the design of the valve body and leakage. This is validated using the computational fluid dynamics model and in experiments. The valve is theoretically modelled considering the switching orifice, leakage, transition throttling and compressibility effect, and the results are validated by computational fluid dynamics and experimental tests. The valve is able to deliver a flow rate of 40 L/min at a pressure drop of 10 bar and switch at the maximum frequency of 317 Hz, with a switching transition time of about 1 ms, which shows promising performance for the use in digital hydraulics. The theoretical and computational fluid dynamics models can assist the design and optimisation of digital high-speed rotary valves, which can be very useful for understanding, analysing and optimising the characteristics and performance of switched inertance hydraulic converters in digital hydraulics.

Parameter Sensitivity Analysis of a Brake Pressure Control System in Aviation Using an Electro-Hydraulic Servo Valve

The landing gear system has the task of bearing the weight of the aircraft, bearing the impact load, and providing the braking function in the process of the aircraft taxiing, take-off, and landing. There are many parameters in the aviation brake pressure servo valve-controlled cylinder system (ABPSVCS) which will have a significant influence on the dynamic behavior of the system. Sensitivity analysis is an effective method to analyze the influence of system parameters on system characteristics, especially for nonlinear systems. The trajectory sensitivity method based on the description of system state space is used for the parameter sensitivity analysis of the ABPSVCS. By grouping various parameters for sensitivity analysis, the law of parameter sensitivity of each group is obtained, and the results are verified by experiments. The results can lay a theoretical and experimental foundation for the related research work of the aviation brake pressure servo valve.

Development of iot Based Water Quality Control and Filtration System

Water is the basic and essential resource which is required for every need such as agriculture, industrial activity and for domestic purpose. Especially in the industrial areas although many water monitoring systems were planted, the waste water disposal is minimally controlled. This project not only helps to monitor water at the industrial level but it can be used anywhere water quality plays a major role. The water quality is continuously monitored with the help of sensors (PH, Temperature, Turbidity, conductivity, water level indicator). It also indicates the level of the water and checking the quality of the water with the help of the valve control system, it sends the water with impurities for the filtration system. The entire system is completely controlled by IOT system and it is continuously monitored by the module.

Synchronization of the movement for multi-cylinder electrohydraulic servo driver

The article presents the problem of synchronization of piston rods velocity of the multi-cylinder electro-hydraulic servo drive. This task was presented on the example of a heavily loaded mobile caterpillar platform. For levelling the platform, a four-post electro-hydraulic support mechanism with a proportional valve control system was used. A linear external controller to synchronize the movement of the cylinders was used and a non-linear internal control system for each of the cylinders lifting the platform.