On-off Solenoid Valves Research Articles

Dynamic modeling, clutch parameter adaptation, and control of automatic transmission for tracked vehicles

In this study, a novel TCU control structure and algorithms including also dynamic model of the transmission will perform the gear shifting of automatic transmissions used in tracked military vehicles are designed. In case of inherent wear of the clutches, the clutch parameters are estimated by means of an adaptation algorithm that uses only the information from the transmission input and output speed sensors. These estimated clutch parameters are used in clutch torque calculation is utilized by control algorithms. For the clutch speed control in the inertia phase, a PID control structure with a negative feedforward term that cancels the nonlinearities of the system is proposed. The feedforward term utilizes the estimated wear clutch coefficients in the calculation of friction coefficients. The parameters of the PID controller are optimized by a genetic algorithm. The designed all structure are firstly tested on a MATLAB/Simulink power train simulation model, and then tested using a unique transmission on a transmission dynamometer test bench to examine its suitability for real transmission scenarios. The performances of proposed PID control and a backstepping nonlinear controller that we constructed for the tracked vehicles are compared with and without clutch wear. Maximum tracking error is decreased by 98% with proposed adaptive PID control structure with nonlinear feedforward term compare to backstepping controller. In the case of clutch wear, the back-stepping control exists in the literature has been found to result in oscillation. By updating the estimated friction coefficient from adaptation algorithm, in the backstepping controller, it is concluded that these oscillations can be eliminated. Additionally, on-off solenoid valves, are widely used, are known to cause torque interruptions and jerks during gear shifting. It has been observed the control structure presented in this study reduced the jerks by one quarter.

Practical hybrid model predictive control for electric pneumatic braking system with on-off solenoid valves

Accurate and rapid braking pressure regulation in electric pneumatic braking systems (EPBS) is vital to vehicle safety. Due to the switching behaviors of the on-off solenoid valves, the operation of the EPBS shows a hybrid nature with both continuous variables and discrete events, which raises the hybrid control problem. One of the possible solutions is to employ the hybrid model predictive controller with the mixed logical dynamical (MLD) model based on the linear approximation of the system dynamics. However, the nonlinearity and complexity of the EPBS make the MLD model obtained by linearizing the system equations directly require high storage and computing capacity. To address these issues, this article presents a practical hybrid model predictive controller based on the system dynamics simplified expressions considering the EPBS pressure variations caused by on-off solenoid valve states at the current sampling time and the last sampling time. The relationship between the pressure variations and the on-off solenoid valve states is first studied by the system mathematical model, followed by applying the mixed logic dynamical modeling approach to establish the hybrid model of the pressure continuous dynamics with discrete features of on-off solenoid valves. Based on these, a hybrid model predictive controller is formulated to solve the EPBS pressure control problem. The simulations and bench experiments are carried out to verify the controller. Besides, an existing model predictive control (MPC) controller is compared with the proposed controller. All the results demonstrate the effectiveness of the hybrid model predictive controller.

A Method for Improving Position Control Performances of a Pneumatic Cylinder Using On-Off Solenoid Valves

Technology using on-off solenoid valves is currently being applied in controlling pneumatic actuators to replace the use of the pneumatic proportional/servo valves. However, controlling the pneumatic actuators using on-off solenoid valves is often difficult due to the low switching frequency of these valves and the high nonlinearity of the pneumatic system. In this paper, we first re-evaluate a controller proposed by Truong in 2020, in which four pneumatic on-off valves were used. We then modify the Truong's controller by dividing the desired position input of the cylinder into two controlled position intervals and each interval will use a separate control law. Seven operating modes of the four on-off solenoid valves combined with the Pulse Width Modulation method (PWM) are used. The experimental research method is carried out. The modified controller is evaluated by comparing it with the Truong’s controller and a controller for a pneumatic system using pneumatic proportional valves at the same conditions of the desired position inputs. Comparison results verify the usefulness of the modified controller.

Pressure control for pneumatic electric braking system of commercial vehicle based on model predictive control

Precise braking pressure control of a pneumatic electric braking system (PEBS) poses challenging non-linear control problems, since it can operate in several distinct discrete processes (the pressure increasing, holding and decreasing) by switching the on-off solenoid valves and the piston of relay valve moves irregularly. This article describes the development and experimental validation of a viable controller for an electronically controlled braking pressure based on the theory of model predictive control (MPC). The controller design consists of two parts. The non-linear characteristic is first studied to ensure the pressure response of PEBS when the opening time is 4–10 ms in a fixed period, followed by calculation and prediction of the optimal on-off time of inlet valve and release valve based on the current braking pressure to realize steady state. A logic rule is designed to ensure that the MPC controller and feedback control work coordinate to guarantee engineering reliability. A comprehensive system model is derived to help characterize system non-linearities and design the MPC predictive model. Simulations and experimental results are presented finally to show how the MPC and feedback control strategy can be successfully applied to solve the braking pressure control of a PEBS in a systematic way.

A novel pulse width modulation for metal radiant panels to control the condensation risk in a hot and humid environment

A novel pulse width modulation (PWM) control method with surface condensation-evaporation cycle was proposed for metal radiant panels to control the condensation risk in hot and humid environments. Through an on-off solenoid valve, a whole cycle of the PWM consists of a fixed on-period duration, i.e., 20 min and an adjustable off-period duration in order to guarantee the formed condensate water on the panel during the on period evaporated completely at the end of the off period. A numerical heat transfer model of the radiant panel validated by experiment was utilized to evaluate the dynamic thermal performance of the PWM. According to the simulation results, the maximum accumulated condensation mass in the whole cycle was far smaller than the falling criteria of condensate droplets, revealing the ability of the PWM in eliminating the negative effects of surface condensation on the indoor environment. Furthermore, compared with the variable temperature control method with a supply water temperature equal to the dew point temperature, the radiant panel utilizing the PWM provided a 10% higher cooling capacity. The radiant metal panels using the PWM has an application prospect for retrofit buildings with low airtightness of the envelope in hot and humid regions by a significant reduction of condensation risks.

Neuro-Fuzzy Volume Control for Quarter Car Air-Spring Suspension System

One type of vehicle suspension system is the air suspension system. One of the important functions of the suspension system is to reduce vibration transmitted to the vehicle body from road unevenness. Soft suspension results in better ride comfort and worst handling. While stiff suspension results in better handling and worse comfort. This paper investigates the performance of air suspension in terms of passenger ride comfort and vehicle handling. The performance is tested once with Fuzzy logic control and another with Fuzzy control augmented with Neuro-Fuzzy inference system. A mathematical model is developed to describe the air-spring stiffness behavior. The air-spring suspension is merged on two degrees of freedom model. The air pressure is controlled by a Fuzzy controller as done previously in the literature. On the other hand, our approach is to control the volume change by connecting the air-spring volume to two additional unequal volumes through ON-OFF solenoid valves. The solenoid valves are controlled by Adaptive Neuro-Fuzzy Inference System (ANFIS). A single-degree-of-freedom setup was built from which the required training data for the ANFIS controller was carried out. The experimental setup is developed with variable excitation input in terms of frequency and amplitudes. The acceleration of the sprung mass has been measured and stored at different operating conditions and including different air volumes. The stored data is used for training of volume controller. The controller is tested with Sinusoidal excitation then with ISO 8608 road profile. It is found that increasing the air volume reduces the sprung mass acceleration. Also, the results showed that implementing the Neuro-Fuzzy controller with Fuzzy logic control reduces the sprung mass acceleration significantly by an average value that reaches 5 cm/s2 at frequencies above 1 Hz while maintaining road holding.

Optimization of the High-speed On-off Valve of an Automatic Transmission

The response time of the high-speed on-off solenoid valve has a great influence on the performance of the automatic transmission. In order to reduce the response time of the high-speed on-off valve, the simulation model of the valve was built by use of AMESim and Ansoft Maxwell softwares. To reduce the response time, an objective function based on ITAE criterion was built and the Genetic Algorithms was used to optimize five parameters including circle number, working air gap, et al. The comparison between experiment and simulation shows that the model is verified. After optimization, the response time of the valve is reduced by 38.16%, the valve can meet the demands of the automatic transmission well. The results can provide theoretical reference for the improvement of automatic transmission performance.

Modeling and PWM Control of Electro-Pneumatic Actuator for Missile Applications.

The Electro-Pneumatic Actuators (EPAs) using ON/OFF type solenoid valves are very popular in aerospace applications due to their robustness, simplicity, high Torque/Weight ratio, fast speed of response, etc. This paper deals with the modeling, simulation, plant characterization, design of a Pulse Width Modulation (PWM) Controller and model validation of an EPA used in missile applications. The EPA used in this work consists of 3-way, 2-position, ON-OFF type solenoid valves. A non-linear mathematical model of the EPA has been developed and implemented in the MATLAB/SIMULINK environment to carry out the simulation studies. The plant model is characterized in the experiment using Frequency Response Analysis (FRA). A Single Sided Pulse Width Modulation (SSPWM) Controller with phase lead-lag compensators and a proportional gain has been designed for the closed loop position control of the missile fin servo. The model is validated by comparing the experimental closed loop time responses with the simulation.

Intelligent real-time pressure tracking system using a novel hybrid control scheme

In this paper, a novel hybrid control scheme is proposed to improve the control performance in a real-time pressure tracking system using fast on-off solenoid valves. In this novel hybrid control scheme, an original approach named Time Interlaced Modulation (TIM) is developed to replace the traditional Pulse Width Modulation (PWM) approach. Besides using TIM, a new switching method which is referred as seven possible control modes is designed to ensure the proper switching states of the valves. Moreover, a controller with field programmable gate array (FPGA) is chosen to guarantee the real-time implementation of the control algorithm. All the simulations and experimental results implemented on FPGA verify the feasibility of the hybrid control scheme.

Force Control for a Pneumatic Cylinder Using Generalized Predictive Controller Approach

Pneumatic cylinder is a well-known device because of its high power to weight ratio, easy use, and environmental safety. Pneumatic cylinder uses air as its power source and converts it to a possible movement such as linear and rotary movement. In order to control the pneumatic cylinder, controller algorithm is needed to control the on-off solenoid valve with encoder and pressure sensor as the feedback inputs. In this paper, generalized predictive controller (GPC) is proposed as the control strategy for the pneumatic cylinder force control. To validate and compare the performance, proportional-integral (PI) controller is also presented. Both controllers algorithms GPC and PI are developed using existing linear model of the cylinder from previous research. Results are presented in simulation and experimental approach using MATLAB-Simulink as the platform. The results show that the GPC is capable of fast response with low steady state error and percentage overshoot compared to PI.

The Influence of On-off Shift Solenoid Valve's Design Parameters on Electromagnetic Force

The integrated transmission device of tank and armored vehicles is controlled by the electro-hydraulic control device, and the On-off shift solenoid valve is just the key component in it. As to models of different air gaps and voltages, through the magnetic circuit partitioning method and the finite element method, the relationship between design parameters and the electromagnetic force is got, and the reference ranges of voltage and gaps for steady electromagnetic force are also obtained from the results, which supply the theoretical basis for the design of structure of the solenoid valve.

Study on Mixture Ratio Control of Bipropellant Propulsion System on Satellite Based on Bypass Control System

Bipropellant propulsion system (MON-1MMH) provides motivation for orbit transfer, attitude control and station keeping, is mainly applied for GEO satellite. Most bipropellant propulsion systems of satellite do not have the ability to control mixture ratio of oxidizer and fuel. The primary function of bypass control system, as an important part of bipropellant propulsion system, is to control helium pressure in the propellant tanks in order to control mixture ratio. This paper researches adjustment of mixture ratio for bipropellant propulsion system. Mathematical model for key components in bypass control system of bipropellant propulsion system and a reasonable model for system simulation combining the practical work of system is established. Through the dynamic simulation of Bang-Bang control with on-off solenoid valve for the adjustment of mixture ratio, structure parameters, working parameters and precision of feedback are all be considered for influence of system performance. The main factors affecting system performance are found out. The researches provide theoretical foundation for engineering implementation.

Using a tracer technique to identify the extent of non-ideal flows in the continuous mixing of non-Newtonian fluids

The identification of non-ideal flows in a continuous-flow mixing of non-Newtonian fluids is a challenging task for various chemical industries: plastic manufacturing, water and wastewater treatment, and pulp and paper manufacturing. Non-ideal flows such as channelling, recirculation, and dead zones significantly affect the performance of continuous-flow mixing systems. Therefore, the main objective of this paper was to develop an identification protocol to measure non-ideal flows in the continuous-flow mixing system. The extent of non-ideal flows was quantified using a dynamic model that incorporated channelling, recirculation, and dead volume in the mixing vessel. To estimate the dynamic model parameters, the system was excited using a frequency-modulated random binary input by injecting the saline solution (as a tracer) into the fresh feed stream prior to being pumped into the mixing vessel. The injection of the tracer was controlled by a computer-controlled on-off solenoid valve. Using the trace technique, the extent of channelling and the effective mixed volume were successfully determined and used as mixing quality criteria. Such identification procedures can be applied at various areas of chemical engineering in order to improve the mixing quality.

Modelling and Controller Design of Electro-Pneumatic Actuator Based on PWM

In this paper, a nonlinear model associated to the fast switching on-off solenoid valve and pneumatic cylinder was dynamically presented. Furthermore, an investigation into the electrical, magnetic, mechanical and fluid subsystems are made. Twocommon control policies to track valve position, a Proportional Integrator (PI) based on Pulse Width Modulation (PWM) and hysteresis controllers, are investigated. To control cylinder position, a Programmable Logic Controller (PLC) on a simulated unit and an experimental setup regulated with AVR microcontroller are carried out. Experimental results show effective validation to the simulation results from PLC. DOI: http://dx.doi.org/10.11591/ijra.v1i3.565

A STUDY OF ON/OFF SOLENOID ACTUATOR WITH POWER SAVING CIRCUIT

The technology of on-off solenoid valves is now considered as a core technology in the fields of the production line of semi-conductor chips and the micro fluid chips for medical applications. And on-off solenoid valves, which operate by compressed air, are characterized by high speed response, great repeatability and that the pressure on the cross sectional area of poppet is kept constant regardless of the fluctuation of the pressure exerted on the ports. The primary objective of this study is to compare the optimally designed solenoid valve with the actually produced one and to design a power saving circuit which can highly improve the efficiency by providing optimal current according to mechanical load. The power saving circuit can be adopted into the 0.35Watt micro valve which has been developed through this study and lower the power consumption of the valve to 0.1 Watt. The absorbing force at 0.3mm stroke, the initial stroke of Plunger and Core, is very large. But the absorbing force at 0mm stroke when Plunger and Core are tightly stuck to each other is several newtons lower than that at the initial stroke, the valve still performs stable and flawless though. It means that with lower current consumption, it still performs stable. Based on that, we've designed the power saving circuit.

Effective Pneumatic Scheme and Control Strategy of a Climbing Robot for Class Wall Cleaning on High-rise Buildings

A new kind of pneumatic climbing robot is presented to meet the requirements of glass-wall cleaning for high-rise buildings, which is totally actuated by pneumatic cylinders and attached to the glass wall with vacuum suckers. Using the pneumatic actuators the climbing robot can be made lightweight and dexterous. At the same time the movement driven by pneumatic actuators has the characteristic of passive compliance. In order to solve the problems of high speed movement for the Y cylinder and precise position control of the X cylinder, the applied pneumatic schemes of X and Y cylinders are employed to drive the high-speed on-off solenoid valves and an ordinary valve to adjust the air-flow and pressure to the cylinders. Furthermore a method of segment and variable bang-bang controller is proposed to implement the accurate control of the position servo system for the X cylinder during the sideways movement. Testing results show that the novel approach can effectively improve the control quality. This cleaning robot can meet the requirements of realization.

Experimenting and modelling the dynamics of pneumatic actuators controlled by the pulse width modulation (PWM) technique

In this paper an extensive set of experiments and a related mathematical model investigating the dynamics of pneumatic actuators controlled by on-off solenoid valves, whose opening and closing time response is based on a pulse width modulation (PWM) technique, is presented. The experimental set-up consists of both commercial electronics and circuits appropriately realized where particular needs are required. As well as providing a highly repeatable set of measurements, valuable for future comparisons, the experimental investigation also provides an appropriate base aimed at testing the performances of the analytical model. The analytical-experimental comparisons show the ability of the theoretical model to provide an accurate mean expectation of the position of the actuator less than about 2 mm. Such a capability of the model is tested for several operating and initial conditions during the first five cycles. The present theoretical model dealing with a non-linear dynamics phenomena whose behaviour is highly transient should be considered an attempt aimed at providing a valuable tool for designing control strategies without the need for expensive physical models.

Component Oriented Modelling and Design of Fuzzy Control Scheme for a Class of Pneumatic Actuators

A class of programmable pneumatic axes has been constructed from a series of 3/2 way on-off solenoid valves and standard commercial components. To compensate for the deficiencies of the stock items, afuzzy logic control scheme has been designed based on a component oriented modelling approach by which the physical system was logically decomposed into components. The basic proportional-derivative control algorithm was then extended with three fuzzy logic control algorithms by considering the effects of individual components on the accuracy of the servomechanism. Tests were performed on two different pneumatic axes. The test results showed that the axes were stable dynamically in all test conditions and could achieve the desired positions accurately. It was concluded that the component oriented modelling methodology provided a robust fuzzy logic control scheme which could be applied to both axes and achieved the same high degree of accuracy even without adjustment to its parameters.

CHARACTERISTICS OF NEW TYPE FLOW CONTROL CARTRIDGE VALVE USING PWM METHOD

The purpose of this study is to combine the good adaptability of PWM control to micro-processor with the adaptability of two-way cartridge valve to high power-level hydraulic systems. In this study, a special cartridge valve, called active cartridge valve, is used. The valve body is incorporated with a piston and the position of the piston, i.e. the opening of the valve, is controlled by the high speed on-off solenoid valve in the pilot circuit using PWM method. As a result the flow rate through the cartridge valve can be controlled by the high speed on-off solenoid valve. The effects of the design parameters on the characteristics of flow control cartridge valve using PWM metho are investigated.

油圧シリンダをアクチュエータとする油圧トランスミッション（ＨＳＴ）の変位制御

This study deals with hydrostatic transmission (HST) which consists of a variable displacement axial piston pump connected in a closed circuit to a load cylinder. The cylinder adopted in this HST-system is an actuator instead of a hydraulic motor in conventional HST-systems in order to realize a translational motion control. For the variation of the swashplate angle of the pump, a hydraulic rotary actuator is used. This actuator is driven by two on-off solenoid valves based on the differential PWM method, for the purpose of making it easier for the HST-system to introduce a digital control algorithm. The system is designed by using an optimal control scheme. It is verified by experiment and digital simulation that the system has good control performance.