Advances in Hydraulic and Pneumatic Drives and Control 2023

The contamination of the working fluid in the hydraulic drives of machines can exceed the permissible values by several times, while the actual time between failures of hydraulic units is significantly lower than the standard. This indicates the need to improve the processes of cleaning the working fluids of hydraulic drives of machines and equipment from mechanical contaminants, for which it is necessary to improve the means of cleaning. Based on this, a new design centrifuge with a hydrojet rotor rotation drive is developed, in which a synergistic combination of several different ways to increase work efficiency was used to increase the efficiency and quality of cleaning the working fluid. A theoretical substantiation of the main parameters of the new centrifuge is made, a prototype is made, its experimental studies and production tests are carried out, some results of which are given in this paper. Because of the experiments, graphical functional dependences of the parameters of the centrifugation process on the main influencing factors are obtained, indicating the high efficiency of the new centrifuge and its ability to reduce the wear of hydraulic units. In addition, the experiments showed a satisfactory accuracy of the obtained theoretical dependencies. Production tests of a prototype of the new centrifuge confirmed the results of laboratory studies and the high efficiency of its operation. The use of a new centrifuge in a hydraulic drive can have a positive economic effect. The new centrifuge can also be used to remove mechanical impurities from a wide variety of technical liquids in various machine and equipment systems.

In the development of spool valves with narrow sealing lands problems with spool sticking were encountered. In previous investigations of this phenomenon bending deformation has been identified as cause. Bending creates a conical sealing gap destabilizing the centered spool position. This leads to substantial lateral forces pressing the spool to the bore and creating high friction forces. In a patent a sealing land modification was proposed which is able to reverse this effect and to stabilize the centric spool position.

In the current paper thorough analyses of the sealing land elastic deformations by the front side and by the sealing gap pressure, their influences on the gap pressure field and on resulting lateral forces are presented. Non-dimensionalization is applied to lower the number of system parameters and to obtain results as generic as possible. Finite Element models for deformation and gap pressure are developed to solve the associated field problems.

Results show that shear deformation of sealing lands with a relatively small radial extension can create a stabilizing conical gap in its center section. General results are presented showing the magnitude of this effect in dependence on design and material parameters, also in comparison to the effect of the gap pressure field and to manufacturing tolerances.

Axial piston pumps are positive displacement units with the highest possible pressures that can be attained. One of the fundamental pairs affecting the energy efficiency of the hydraulic machine is the cylinder block –valve plate. The work presents the construction of an axial piston pump. Three possible designs of the valve plate were analyzed, namely the design with positive overlap, zero overlap and the one, that is most often used, i.e. with relief grooves. Relationships for the distribution of hydrostatic pressure on the valve plate in the zone high pressure on the inner, outer and middle rings in dependence on the angle of rotation of the cylinder block were developed. Subsequently the location of the resultant hydrostatic forces occurring on the valve plate in the zone high pressure and the upper and lower transition zones relief the cylinder block during its rotation were depicted. Using the MathCad 2001 [5] program, computational simulations of the movement trajectories of the resultant pressing forces acting on the bottoms of the cylinder block located in the zone high pressure and the resultant hydrostatic forces relief the cylinder block during its rotation were performed. For example, the trajectory of the movement of hydrostatic forces pressing and relief the cylinder block for the zero overlap of the valve plate was presented. The work is completed with substantive conclusions.

Vane pumps are widely used in many applications and often are the source of flow in hydrostatic power transmission systems. The paper deals with visualization methods of fluid flow inside a single-chamber vane pump. In this article, a stand for investigating flow phenomena in vane pumps was presented with the use of a high-speed camera. Due to the complex nature of the flow and limitations of the visual experimental method, a numerical model of the chosen pump was prepared. CFD flow simulations were performed for different values of suction pressure, discharge pressure and rotation speed. Comparison of the results of visual experimental investigation and computer simulation showed that CFD modeling can be successfully used for the prediction of fluid flow inside different vane pumps.

This article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in the working chambers, but also a non-linear function of the motor speed. The results of the experimental tests of the satellite motor are also described. Analysis of the test results confirmed the correctness of the method for determining both the theoretical working volume and the actual working volume. It was also shown that the calculation of the partial efficiencies (i.e. mechanical efficiency and volumetric efficiency) of a hydraulic motor should be based on the actual working volume instead of the theoretical one.

The use of digital pumps in place of traditional “analog” pumps is a fresh, promising strategy. A digital pump is made up of numerous sequential shifting valves and continuous pumps. During partial load function, digital pumps often perform more efficiently than traditional pumps. The paper will include a description of the valves structure and their connections suitable for three pumps on one shaft as well as discussion of digital hydraulic technology and digital valves as well as hydrostatic drive system.

The progressive miniaturization in electronic system design allows us to implement digital controllers in an increasingly compact form, including installation directly in the hydraulic device. The control signals can be sent remotely from an external controller, or the built-in system can independently implement the control algorithm to some extent. The paper presents the results of numerical and experimental studies of a digital control system implemented in a variable displacement vane pump. It allows various control strategies to be implemented, including fixed value pressure control, constant power control, etc. The flow rate is set by controlling the position of the stator, while the pressure can be regulated using the built-in proportional valve. A mathematical pump and control system model was built as part of the work. Next, simulations were carried out in Matlab/Simulink environment, considering the dynamics of the system. To verify the mathematical model, a test bench was built for carrying out laboratory experiments with typical loads and changes in pump flow rate.

The article presents considerations of controlling the hydraulic power source according to the principle of forced flow. In systems with forced flow, the pump generates a flow of liquid regardless of the load level. A pump with a constant geometric capacity produces an appropriate liquid stream by changing the rotational speed of its drive. The use of a pump with constant capacity in the hydraulic system, driven at variable speed employing an adjustable electric drive powered by a variable frequency drive (VFD), ensures high dynamics of fluid stream changes, good control quality of the hydrostatic drive, energy efficiency and low noise emission. The use of a dedicated measurement system in the hydrostatic power system enables the development of control methods for hydraulic drive systems that maintain constant efficiency, pressure and power output. The conducted simulation and experimental studies show the legitimacy of using new control methods in hydrostatic power supply systems.

This paper presents a control concept for a hardware-in-the-loop test rig. The aim is to develop optimized control concepts for aircraft fatigue tests, without risking component damage. The test rig simulates a mechanical structure´s response on a force-controlled axis through two servohydraulic axes. Since speed and position have a significant influence on the force control, both must be controlled as precisely as possible and independently of the force control. Classic single-loop PID controllers are not sufficient in this case. Therefore, a control concept consisting of a position controller and a velocity feedforward control using a characteristic map for partial linearization of the controlled system is proposed.

The performance of the controller is compared with a single-loop PID control through step tests, and its influence on system dynamics is analyzed. The results show that the proposed control concept leads to better control behavior without noticeable overshooting compared to the PID control. The use of a characteristic map for load pressure correction also simplifies the mapping of non-linear behavior of hydraulic valves and determination of suitable parameters for feedback only considering information usually available from data-sheets.

The paper is focused on the Model Based Design of the closed loop control of the linear hydraulic drive. Model-Based-Design is progressive methodology for design of control systems, embedded control systems and for testing of the implemented software. The hydraulic servo drives represent very important parts of the modern machines. The demands on their accuracy and dynamics require the use of the modern controller design approaches based on the computer simulation and comprehensive tools of their implementation. The novel created MATLAB-application named Hydraulic System Control–Model Based Design is introduced. The application concentrates the knowledge of the possible solutions of the closed loop control systems suitable for hydraulic drives and supports the use and tuning of the controllers different structures. The parameterization of the drive can be done using the known data from the data sheets of the servo valve and cylinder or can be based on the experimentally obtained characteristics which can be evaluated using the identification methods. The application is a user-friendly environment and creates also comfortable access to the MATLAB-toolboxes and their use. It simplifies the process of the controller design based on the implemented non-linear, linear respectively linearized mathematical models of the hydraulic drive, because the tools for the linearization of the non-linear model are available. The parameters of the controller can be verified by the simulation of the linear or non-linear model. The created MATLAB-application represents the Model-in-the-Loop (MIL) simulation of the control of the hydraulic drive and supports very important part of the development cycle called V-Model. Practical use of the application is demonstrated on the design of the closed loop position control of the hydraulic drive installed on the test rig. The simulated and measured data are presented as well as the results of the Hardware-in-the-Loop simulation of the control of the laboratory hydraulic drive.

The article presents a qualitative and quantitative comparative analysis of the currently used hydrostatic-mechanical wheel drive systems on the example of a wheel loader. In addition to the conventional systems in common use, the analysis also takes into account the future system of direct, individual wheel drive by means of a variable displacement hydrostatic pump-motor. The object generating the boundary conditions for comparison is a typical midi class wheel loader weighing 8 tonnes. Current hydrostatic drive systems for wheeled chassis have a number of limitations due to the configuration of the entire drive system as well as the design of the hydrostatic pumps and motors themselves. Beginning with the typical drive made up of axle and an intermediate gearbox driven by a bent axis variable displacement motor and ending with the aforementioned pump-motor solution, there are significant differences in the actual useful functionality of all drive systems. This functionality translates into the static and dynamic characteristics of the individual drive systems, significantly influencing wheel loader performance, operating economy, reliability and operator comfort. At present, individual direct wheel drive systems are built using slow-speed motors with stepwise or infinitely variable displacement, but within a given range, which imposes limitations on the system’s use. One of the fundamental parameters is the maximum speed of the wheeled chassis equipped with such a system, limited to several km/h, while an innovative system based on a hydrostatic pump-motor with variable displacement does not have this limitation.

Subject of the article is an innovative modular load sensing (LS) system, which allows for free creation of hydraulic control systems in terms of the structure of functions and control logic, as well as in terms of their design, enabling free valve placing and adjustment of the valve block dimensions for installation. So far known mobile-type LS systems have mainly form of block manifolds, most often multi-section ones. The innovative LS modular system has been designed for the commonly used industrial standard, often called CETOP, which meets ISO 4401 mounting subplate pattern. To transmit LS signal the system uses port (X), which is dedicated to control line. The LS system (B type) presented in the article consists of two basic modules: an element for obtaining and processing the LS signal and an element for controlling the delivery of a constant pump, which for the LS type variable pump is unnecessary. As part of the developed system, few modified and adapted valve types and accessories were proposed, including e.g. directional control valves as an option. All other elements for building the system, the 4-way directional valves (classical and proportional) and modular (sandwich) valves are available on the CETOP valve market. The proposed LS system allows for cheap and easy way to apply the LS technology in industrial standard, as well as to easily modify existing systems, which enables energy savings. The article presents operation characteristics and also comparative analyzes of the energy efficiency of control systems with the applied LS-B system vs similar standard ones for several selected scenarios of system operation. The presented solution is patent pending.

Rehabilitation of people with lower limb dysfunctions concerns people after orthopedic injuries, strokes and at present mainly elderly people. As a result of the extension of human life, civilization progress and improvement in the quality of life in the world, the percentage of people in post-working age is systematically growing. This trend is particularly visible in highly developed countries. The most common of musculoskeletal disorders in the elderly is osteoarthritis of the large joints of the limbs. Currently more than 55 million people live with dementia worldwide, and there are nearly 10 million new cases every year. Degenerative changes are mostly caused by obesity, excessive overload in earlier periods of life (hard physical work) and metabolic disorders. Rehabilitation of people is aimed at preventing the dangerous consequences of long-term immobilization, maintaining the physiological range of motion in the joint, preventing the formation of contractures and preventing degeneration of the articular cartilage. An important challenge is the activation of the elderly through devices supporting movement and rehabilitation devices. One of the possibilities are three-wheeled rehabilitation bicycles. The article presents the design of a three-wheeled rehabilitation bicycle with an innovative pneumatic drive. Thanks to the solutions used, the tricycle is environmentally friendly. Heavy and problematic to dispose of gel or lithium-ion batteries were eliminated and replaced with composite cylinders for high-pressure compressed air. The tricycle is characterized by many positive features, such as: quiet operation, low weight, the ability to adjust the load on the rehabilitated limbs, the ability to move freely in the absence of a power source and travel at high speed.

The article contains an analysis of the possibility of precise position control of a bellows actuator. For this purpose, a special research stand was built. It allows an accurate determination of the static and dynamic characteristics of air springs under variable loads generated by a pneumatic cylinder. The bellows is placed on a prototype base, enabling, apart from precise height measurement, determination of changes in the volume of the bellows immersed in liquid. Based on the experimental data, a formula for the effective area of the bellows was derived, depending on its height and the applied load. Subsequently, a mathematical model of the stand was made which was used to carry out further simulation tests in the MATLAB /SIMULINK environment.

The paper investigates wave interference (between pressure waves) occurring in simple hydraulic systems. Water hammer was induced by simultaneous closure of three valves located at the reservoirs of a “Y” type hydraulic system. Numerical simulations were carried out with the help of the freeware computer package Allievi enabling the reader to replicate results in a direct manner. The influence of the following quantities has been tested: Reynolds number Re (laminar and turbulent flow), the length of the pipe arms (L₁, L₂, L₃), the constant pipe internal diameter (D_i = const.) and variable internal pipe diameters D_i (D₁ ≠ D₂ ≠ D₃). The results of the research showed how unwanted interferences between pressure waves may occur and thus increase the possibility of piping system damage. Further numerical investigations are sought in consideration of unsteady skin friction losses and viscoelastic pipe wall effects.

This article deals with the evaluation of the hydraulic modules used in the ZSM (Zrobotyzowany System Murarski) mobile robotic bricklaying system. This robotics bricklaying system was developed as a research project in cooperation between a scientific leader, the research and development partner, and the industry partner. Mobile ZSM is the first robotic brickwork system in Poland, designed primarily for the construction of facades and partitions in office and residential buildings, as well as in industrial buildings. A mobile ZSM has been designed and developed as an innovative demonstration solution for the construction industry to automate heavy, labour-intensive and burdensome masonry work traditionally done manually by masons. The ZSM mobile set was made up of an ABB industrial robot with six degrees of freedom (6DoF), a Hinowa tracked undercarriage, a robot support frame, a hydraulic lifting-levelling unit, a brick warehouse, a brick feeder, a mortar applicator, a control cabinet, an operator panel, and a hydraulic gripper. The evaluation involved the specified hydraulic modules of the mobile ZSM, such as the hydraulic power and control unit, the hydraulic drive of the tracked undercarriage, hydraulic control of the lifting-levelling unit, and the hydraulic robot gripper. The human-machine interface (HMI) operator touch panel was presented with the start screen and control screens for the individual hydraulic modules of the mobile ZSM. The HMI touch panel was visually programmed to manage the mobile ZSM.

The paper presents a simulation model of a hydrostatic transmission consisting of a piston pump and a receiver in the form of a hydraulic motor with an energy compensation system. The current state of research in this area and the patent reservations made by the authors are presented. Possible applications of the solution will be discussed: recovering energy from vehicle suspension and producing electricity in wave power plants, taking into account ecological aspects.

Reducing the noxious emissions from internal combustion engines is one of the factors that can contribute to amending the quality of the environment in which we live. Even if the efforts and results of the last decades are more visible in the field of road vehicles, the equipment used in the construction field also registers progress in reducing consumption and especially CO₂ emissions. To reduce consumption, equipment manufacturers have applied various hybridization solutions, from the simplest ones that use energy recovery systems to those that use both internal combustion engines and electric motors. A special case is encountered when noxious emissions are completely prohibited, such as work performed in enclosed spaces or which cannot be properly ventilated. In these cases, the only solution is to obtain the necessary energy with an electric motor powered by batteries, in order to drive the transmission and the equipment mounted on the machine. Since hydraulic drive is difficult to replace in machines working in harsh conditions, the hydraulic pumps must be driven by electric motors. The article presents such a machine solution, which uses as the primary source of energy either a regular internal combustion engine or an electric motor powered by batteries.

The article presents the results of a comparative analysis of pressure characteristics in the hydrostatic drive systems of blasting utility vehicles WS-153/173 currently operated and developed for the purpose of loading explosive charges in underground ore mines. The two compared solutions are both designed on the basis of variable displacement pumps with LS (Load Sensing) control. In the first solution, such pumps power all of the hydraulic operating elements, and in the second solution some of the auxiliary elements are powered independently by an added fixed displacement pump, thus reducing both the number of hydraulic energy receivers and the maximum flow rate on the line powered by LS pumps. The article presents and discusses the different time-pressure curves as recorded in typical operating procedures during tests performed on both of the analyzed systems. It also investigates the impact of the introduced modifications on the operation of the analyzed hydrostatic systems. The results of these research and development works seem an interesting material, in which actual devices are used as a direct example of a method for improving the parameters of hydraulic systems with LS pumps by modifying the system architecture.

The principles of designing hydraulic cylinders are generally known, but metals are assumed to be typical design materials for cylinders, which results in the use of standard design solutions and typical manufacturing technologies. However, the use of special design materials, e.g. plastics or composites, may require a departure from traditional, generic methods, or at least an adaptation of them. The article presents the specificity of designing cylinders made of plastics, which have been determined as a result of research presented in the author's earlier publications. The specificity of the designing is presented in an orderly manner, by following the stages of the author’s algorithm for designing cylinders made of plastics. The specific challenges connected with this process are presented, which are different for the designing of plastic cylinders and metal cylinders. Some suggested solutions and examples of their practical application are also indicated. In the summary, possibilities offered by the use of plastics in hydraulic cylinders are considered.

This research aims to investigate the flow characteristics of plastic valves with 3D-printed poppets using Computational Fluid Dynamics (CFD) simulations and experimental validation. Plastic valves have been gaining popularity in various industries due to their lightweight, corrosion resistance, and low cost. However, the use of plastic valves in fluid flow applications is still limited due to concerns about their durability and performance. The poppet, being the main component of a valve, plays a crucial role in determining the valve’s performance. In this study, poppets have been 3D printed using polylactic acid (PLA) material. Different poppets shapes were tested using CFD simulations and experimental tests to obtain pressure-flow characteristics. The numerical approach to obtain the valves flow characteristics includes the cavitation model to ensure better agreement with the experimental data. The results of this research provide insights into the suitability of plastic valves for various applications and the importance of experimental validation in the design process.

Hydraulic pumps are a crucial part of every hydraulic system and have been built with similar tribological systems for decades. In a typical axial piston pump, the high surface pressures are hydrostatically balanced, and the residual contact is taken by a steel – special brass contact.

Due to the increasingly complex requirements, such as higher requested speeds and operating pressures, as well as legal constraints, such as the restriction of lead and the use of biodegradable oils, alternatives have to be found for the often-used lead-containing special brass.

Laser coatings applied by means of Extreme High-Speed Laser Application (EHLA) are a possible alternative. These promise almost complete freedom in terms of material selection and impress with a fast and cost-effective coating process.

In preliminary work, the process of material pre-selection by disc-disc tribometer testing up to the first running pump prototype was shown. The results obtained indicated, that with the choice of much harder contact partners, the run-in process also needs to be reconsidered.

In this study, a completely new, laser coated tribological system is tested in a real application. Special focus is set on the operational behavior and efficiency during the first 1000 h of operation, compared to the standard pump.

The issue of the physics process of hydrodynamic luminescence formation requires careful research. In scientific and technical literature, two terms denoting the glow of a liquid are widely used: sonoluminescence and light emission. The first term is directly related to ultrasound as the cause the liquid to glow; the second - provides a wider range of reasons that cause the glow. One way or another, both processes have two main theories of their occurrence – “thermal” and “electric”. The “thermal” theory assumes that when an external influence is applied to a cavitating bubble, high temperatures are formed inside it, which stimulate the emission of radiation by the bubble. The “electrical” theory is based on electrical phenomena inside the bubble itself or interaction with nearby cavitating bubbles.

The practical value of the work results is determined by the search for a reliable theory of the phenomenon of hydrodynamic luminescence. The obtained results contribute to a deeper understanding of the studied phenomena and create a basis for the development of an experimentally based theory of the origin of the phenomena of sonoluminescence and hydroluminescence, which has a positive effect on the introduction of these phenomena into technological processes.

The relevance of the study is also due to the wide use of dielectric pipelines when supplying hydrocarbon and other liquids to various technical devices. In the future, it is possible to use these processes in the chemistry, pharmaceutical industry, and the creation of effective methods of surface treatment with liquids.

Increasing production costs require the search for new cheaper or more durable solutions for hydraulic components, such as actuators. Direction of the development of actuator constructions is to apply new methods of modifying surfaces of working elements, for example, pistons and piston rods. Operation of actuators under high pressure and variable temperatures, additionally in a hydraulic oil environment, requires special properties of the surfaces, in particular, low friction coefficients, high hardness, and resistance to abrasion, corrosion, or aggressive environments. This paper presents a test stand for actuators with various working surfaces. The test stand can be used for long-term tests (fatigue tests) performed on four actuators simultaneously, as well as for testing selected parameters, such as mechanical-hydraulic efficiency. One of the actuators is a reference actuator made of typical material and standard surface modification, while the others are manufactured using modern surface modification methods, such as nitriding, nitrosulphurization, or application of a DLC carbon coating enriched with tungsten carbide particles. The design of the workstations makes it possible to set different load levels on all cylinders simultaneously, as well as different operating speeds. All important parameters of the working cycles and the number of cycles performed are measured. The article presents examples of measurement cycles.

The current article presents the research results of the proposed energy-saving way in hydraulic drives based on a biomimetic approach. Experimental measuring for investigation energy consumption by different types of high-pressure hoses and its influence on the inside fluid flow are presented. The methodology presented in this paper for experimental measurement is based on fluid pressure measuring and high-pressure hose vibration measuring analysis. In the research, by experimental measuring, different braided high-pressure hoses, used in modern hydraulic drives, were compared. The research was performed to describe a high-pressure hose behavior dependency on the fluid flow inside and its influence on the energy parameters of the system. The proposed concept for energy-saving in a hydraulic drive is based on biomimetic approaches. In the research it is disclosed that, by using different types of high-pressure hoses, a reduce of power losses and an increasing hydraulic drive efficiency can be achieved, by replacing one type of a high-pressure hose with another type, during machinery hydraulic drive maintenance or on design stage.

The article presents an original test rig for investigating the dynamic and static properties of hydraulic hoses. A composite micro-hydraulic hose with an inner diameter of 2 mm was taken as the test object. To carry out hydrodynamic tests in a composite hydraulic micro-hose, a test rig was built. The test stand consists of a hydraulic system whose purpose is to supply the test object with working fluid, and measurement paths that allow observation of hydrodynamic phenomena occurring in the tested hose. In addition, the test stand was equipped with a working fluid temperature stabilization system. The measured values during the measurement series were: pressure at the beginning and at the end of the tested hose (AC and DC components), temperature of the fluid inside the micro-hose at the beginning and at the end, vibrations in three directions at a selected point of the micro-hose, tension force of the micro-hose (DC and AC component), reaction in the supports (DC and AC component), fluid flow rate in the micro-hose, displacement of the movable support differential with the axial deformation of the micro-hose. In the research was determined the influence of the mean pressure value on the amplitude of micro-hose vibrations. Amplitude-frequency spectra were used to analyses the results obtained.

The world society is facing the threats of global energy and environmental crises. A significant decrease in natural resources, including various types of fuel, and the aggravation of environmental issues have led to the need to find alternative energy sources, one of which is hydrogen. Therefore, a large number of researchers are currently working on creating new or improving existing methods for the production of hydrogen gas. There are many developments in this area, but there is still no sufficiently efficient hydrogen production technology.

It is a well-known technology to produce hydrogen through the interaction of aluminum or its alloys with water, but this reaction quickly fades away due to the formation of an oxide film on the aluminum surface. Therefore, to maintain the high efficiency of the technology, it was proposed to carry out this reaction under ultrasonic cavitation.

The use of ultrasonic cavitation in the chemical process of water-aluminum interaction ensures, due to ultrasonic erosion, the permanent destruction of the oxide film on the aluminum surface, which allows for maximum efficiency and stability of the chemical reaction of hydrogen removal and aluminum hydroxide production. In the cavitation environment, aluminum particles are further dispersed into smaller ones, which leads to an additional increase in the contact surface of water and pure aluminum. As a result, it is possible to almost fully utilize the capabilities of pure aluminum in the chemical reaction of hydrogen production from water. The use of ultrasonic atomization in a thin layer device makes it possible to obtain monodispersed aluminum powder with the required dimensions, according to calculations.

The proposed technology allows not only to produce hydrogen in a way that is safe for humans and the environment, but also to eliminate one of the many causes of environmental pollution associated with the disposal of household and industrial waste.

This paper presents the virtual prototyping of a hydrotronic hydraulic actuator position control system. The hydraulic actuator is part of a test bench for pneumatic vibration isolation systems. It should force a sinusoidally variable movement of the device platform. The amplitude and frequency of this movement are set and changed according to testing needs. The control system under development was based on the Danfoss Plus + 1 series proportional directional valves and controllers. The article focuses on discussing the synthesis of the control algorithm and presenting the simulation method used to predict the dynamic capabilities of the designed system.

There is a relationship between design and operational parameters in the context of the influence of vibrations on the operation of micro-hydraulic components. The analysis of the author's and co-author's research work to date indicates the need to carry out research related to determining the influence of structural parameters, i.e. valve seat diameter, type and stiffness of the spring, different design of the side slope of the cone of the closing element, and operational parameters, i.e. flow rate, operating pressures, on the frequency of external mechanical vibrations acting on the microvalve. Previous analyses have been carried out using the method of multi- valued logic trees, and induction trees, which have tentatively determined the rank of importance of design parameters on pressure pulsations during the occurrence of external mechanical vibrations. For a comprehensive analysis, it was decided to use a rule-based expert system (BrES) as a decision support tool.