Hydraulic Research Articles

Adaptive robust motion control for hydraulic load sensitive systems considering displacement dynamic compensation

Hydraulic load-sensitive systems (HLSS) are widely used for high power density and energy efficiency. This study introduces an adaptive, energy-efficient HLSS with a valve-controlled variable motor. The system faces challenges from non-linearities, including internal higher-order dynamics due to displacement changes and external unknown disturbances, which hinder precision applications. To address this issue, this study explores HLSS principles to develop an accurate system model. Subsequently, an adaptive robust motion control that considers displacement compensation (DCARC) is proposed using the established model. DCARC can learn unknown parameters online and compensate the model more accurately to improve control accuracy. Experiments show that considering the higher order dynamic effects caused by displacement in the system can improve model accuracy and effectively reduce the burden of parameter adaptation and robust feedback terms. High-precision and energy-efficient HLSS motion is verified and realized in the study. The control accuracy of DCARC is 19.4% higher than that of conventional adaptive robust control (ARC). Under experimental conditions, the proposed system can improve energy efficiency by up to five times compared to valve-controlled fixed displacement motor systems (VFDS).

Identification of incipient cavitation in control valve

Control valves as important elements in hydraulic systems are used to transport liquid and gaseous media, for example, water, water vapor, and hydrogen. They are mainly used in the power engineering, chemical industry, and so forth. Due to their large dimensions, the verification of hydraulic parameters is problematic. In the case of liquid flow, cavitation can occur, which is mainly characterized by noise, vibrations, or changes of hydraulic parameters. During the incipient cavitation in the valve, there are no noticeable changes in the hydraulic characteristics. The article, therefore, deals with the methodology of determining the cavitation by measuring and evaluating the characteristics of the valve, spectral analysis of noise, and vibrations during water flow. Mathematical modeling is also a suitable tool for determining the extent of cavitation in valve design. Newly created modified cavitation model, where the flowing medium is defined as a mixture of incompressible water and compressible gases (vapor and air), better corresponds to physical principles than the two-phase approach (water and vapor) with experimentally modified density and viscosity. Measured noise and vibration frequency characteristics and mathematically modeled pressure frequency characteristics identify cavitation in the (1 to 10) kHz range. The article proves that when identifying cavitation, the method of measuring hydraulic characteristics fails, but the method of measuring noise and vibrations is suitable in practice, i.e., in real industrial equipment, and the modified cavitation model is suitable for identifying cavitation regions in structural designs of the hydraulic elements.

Review of studies on the design optimization of hydraulic cartridge valves

Hydraulic cartridge valves are extensively used across numerous industries, attributed to their exceptional integration and potent flow capacity. To effectively address the varied load conditions, environmental influences, and durability demands in different contexts, it is crucial for designers to optimize these valves. Currently, a significant number of scholars have undertaken invaluable research on the design optimization of cartridge valves. The objective of this paper is to propose research concepts for the design optimization of hydraulic cartridge valves by analyzing the current literature and thereby boost the performance of hydraulic cartridge valve systems. This paper adopts a mixed review method, elaborating on the literature search methodology for reviews concerning cartridge valve design optimization. The obtained results are subjected to quantitative analysis. Following this, a thorough review of the identified literature is provided, focusing on the methodology and performance concerns of hydraulic cartridge valve design optimization. Finally, the prerequisites and challenges associated with the cartridge valve design optimization approach are discussed in detail, considering aspects such as compact lightweight design, reliability enhancement, and intelligent design optimization.

Research on the viscosity characteristics of water glycol hydraulic fluids in deep-sea environment from molecular dynamics

The utilization of water glycol as a working medium represents a significant advancement in the realm of deep-sea hydraulic transmission systems. The viscosity of water glycol is a crucial parameter for hydrodynamic lubrication, yet it is profoundly influenced by the environmental conditions of the deep sea. This study employs the TIP4P/2005 water molecule model in conjunction with the optimized potentials for liquid simulations all-atom force field, and non-equilibrium molecular dynamics method to predict the viscosity of water glycol hydraulic fluids with varying compositions under deep-sea conditions. The simulation values agree well with the experimental results. Furthermore, this study introduces a fitting equation that accounts for the effects of composition, temperature, and pressure, enabling the prediction of the viscosity of water glycol hydraulic fluids within the 0–11 000 m sea water environment.

High-sensitivity and high-resolution triboelectric acoustic sensor for mechanical equipment monitoring

Traditional sensors for mechanical equipment monitoring often face challenges such as high cost, difficult installation and removal, and reliance on power sources. Herein, we introduced a polyvinylidene fluoride (PVDF) nanofiber membrane doped with BaTiO3 for constructing a triboelectric acoustic sensor (PB-TAS), innovatively designed for monitoring and recognizing the working conditions of mechanical equipment. This represents the first application of a triboelectric acoustic sensor for mechanical equipment monitoring. The PB-TAS demonstrates an ultra-broad frequency response range of 20–20,000 Hz, effectively covering the characteristic frequency spectrum (within 2000 Hz) during piston pump operation. It also exhibits extraordinarily sensitivity of 4.40 V Pa−1 at 85 dB, and ultra-high frequency resolution down to 0.1 Hz, enabling precise matching of the piston pump's acoustic characteristic frequencies. Integrated with deep learning techniques, the PB-TAS achieves real-time recognition of 15 distinct working conditions of a piston pump, with an impressive accuracy of 95.2 %. The PB-TAS, boasting exceptional sensitivity and frequency resolution, offers a cost-effective, miniaturized, self-powered, non-contact, and highly accurate solution for intelligent monitoring of hydraulic piston pumps.

СИНХРОНИЗАЦИЯ ПОДАЧИ СЕМЯН И РАБОЧЕЙ ЖИДКОСТИ В КАМЕРУ СМЕШИВАНИЯ ПРОТРАВЛИВАТЕЛЯ

The results of production tests of the PS-20K-4 seed dresser with a modified electrical control circuit in order to synchronize the supply of seeds and working fluid to the mixing chamber of the treater when it is put into operation are presented. At each start-up of the dressers, the supply of seeds to the chamber is ahead of the supply of working fluid to it due to the inertia of the working bodies of the hydraulic system, especially this is manifested on dressing machines equipped with centrifugal pumps for supplying working fluid (PS-20K-4, PS-22, etc.). To ensure the synchronization of the supply of seeds and working fluid to the mixing chamber, a device is proposed, the main part of which is the PVI-11 time delay relay for switching on the seed disc drive. Before starting the dresser, the time of movement of the liquid from the pump to the sprayer is determined. For the time obtained in this way, a delay is set on the PVI-11 attachment. Production tests have shown the advantage of the treater with changes made to the electrical control circuit. With the factory control scheme of the treater, the total weight of untreated seeds and seeds with reduced completeness of treatment, which are defective, increases with the increase in the installed capacity of the unit from 5 to 20 t/h, respectively from 26.4 to 48 kg at the beginning of each machine start-up. With the established synchronization of the supply of seeds and working fluid to the mixing chamber when starting the dressing machine, there were no defective seeds. Operational, technological, technical and economic evaluations of the unit showed that the shift time utilization factor was τ_c = 0.83, Shift productivity increased by 25 % due to a reduction in the time for additional treatment of untreated and insufficiently treated seeds. The indicators of technical and operational reliability were Ktn = 0.98 and Ken = 0.94, respectively. Reduced costs by 35%, reducing labor costs by 25%. The annual economic effect with 140 hours of operating amounted to 29915.6 thousand rubles.

ОБОСНОВАНИЕ ПАРАМЕТРОВ ТЕХНИЧЕСКОГО СРЕДСТВА ДЛЯ КРАЕВОЙ ОБРАБОТКИ ПОЛЯ ОТ СОРНЯКОВ И ВРЕДИТЕЛЕЙ ПОЛЕВЫХ КУЛЬТУР

The main method of spraying for plant protection in the fight against weeds and pests in the marginal area of the field with forest plantations is currently implemented by various technical means. The following shortcomings have been identified: when using the main chemical method of spraying weeds and pests by technical means, universal requirements for droplet dispersion are not met; when spraying the forest belt with fans - instability of aerosol jets in the external environment; when creating a cold aerosol with fans - uncontrollability for achieving the required dispersion, and when creating a cold aerosol with generators, the initial conditions of its formation are insufficient to justify the spread of dispersion as intended; when using aerosol generators with a thermo-mechanical principle of operation - non-compliance with modern environmental requirements. The recommendations for the use of air means given in literary sources are not relevant. The technical means including an axial fan with a diameter of 0.61 m and an air capacity of 22,000 m3 /h were studied. The conical nozzle was equipped with nozzles with spray tips on its generatrix. The working process of the axial fan with a hydraulic motor was provided by the tractor hydraulic system, and the supply of working fluid from the sprayer tank to the spray tips was carried out by a pump. Theoretical studies were conducted to justify the nozzle to the fan with the justification for creating an air-dispersed system and settling polydisperse droplets from it on the target objects. Experimental data on the dispersion of droplets were processed using software. The results of the studies represent the novelty of theoretical and practical solutions for the combined use of the process of spraying the edge area of the field with its further development in practical application for plant protection.

Minimally Invasive Sinus Augmentation: A Systematic Review.

Technology improvement and a better understanding of sinus anatomy and wound healing in the past decade have allowed the development of minimally invasive surgical techniques. This systematic review focused on identifying and describing these techniques for vertical and lateral sinus augmentation (VSA and LSA). Electronic and hand search were conducted to screen the literature published from January 2003 to May 2024. The selected studies had to include detailed techniques for minimally invasive SA. Data extraction included the study types, sample size, technique/instrument details, and outcome measurements. A total of 36 articles (27 VSA, 8 LSA with an additional 1 article included both procedures) with 2732 sinus augmentation met the inclusion criteria. Minimally invasive VSA includes the use of modified rotary instruments with stopper, balloon, hydraulic pressure, digital planning, endoscope, and operating microscope. These techniques aim for conservative flap reflection, precise sinus window preparation, and/or controlled sinus membrane elevation. Most of the selected studies (n = 15) did not report the incidence of sinus membrane perforation. Within the limitations of this review, minimally invasive VSA and LSA achieved sufficient sinus augmentation and implant success with the potential advantages of reduced surgical complications and morbidity. Comparative studies with defined outcomes are encouraged to further validate these useful minimally invasive techniques for SA.

Environmental protection, health, and occupational safety initiatives: Reducing filter waste and environmental contamination from oil leaks in coal mining excavators

Background: Hazardous and toxic waste contamination in the mining industry is primarily generated from the servicing and maintenance of heavy equipment. One of the key issues in this process is hydraulic oil leaks in excavator units. Additionally, the use of B30 fuel impacts the filter replacement interval, as its lifetime is shorter, thereby contributing to the amount of hazardous and toxic waste. Based on data obtained during the August-November 2023 period, hydraulic system leaks amounted to 4,899 liters. The aim of this study is to assess the implementation of improvement plans aimed at reducing filter waste and environmental contamination caused by oil leaks in excavators. Method: This study is a descriptive quantitative analysis aimed at describing the impact of strategies implemented to reduce filter waste and environmental contamination caused by oil leaks in excavators. The research was conducted at PT. Anteraja Mahada Makmur (PT. AMM) on the jobsite of PT. Multi Harapan Utama (PT. MHU) from August 2023 to March 2024. The variables studied included strategic steps composed of alternative solutions, which serve as the foundation for planning the repair of oil leaks and engine filter damage. The population of the study encompasses all maintenance activities within the company, involving personnel, materials, environment, machinery, and methods. The sample focuses specifically on maintenance activities involving factors that experience deviations, such as personnel, machinery, and methods. Results: The implementation of the improvement plan consists of creating a Standard Form for Follow up suggestion, Creating a special Group for equipment health, Adding a discussion of Plant service H+2 and details of Follow up Equipment Health activities, Cleaning the radiator every 6000 hours by lowering it, Activating tropical spec (+55 degrees) by jumpering CN05 Controller Pump, Installing additional filters to reduce the load on the main filter, Creating Guidance PPM (Machine Inspection Program) and Standardizing Hydraulic Pressure, Sharing Knowledge related to the Hydraulic System, Rebuilding existing tools with available materials, Installing Autodownload VHMS on the Big Digger unit, Developing SS6 for web-based data processing. Conclusion: The implementation of the improvement plan strategy carried out at PT. AMM Site MHU went well and showed maximum results. This can be seen from the positive changes for all elements targeted for improvement (man/workers, machines and methods) which generally have an impact on reducing engine filter waste and environmental contamination due to oil leaks in the excavator unit.

Design and fabrication of ultrathin silicon-based strain gauges for piezoresistive pressure sensor

Ultra-thin (20 μm) silicon strain gauges were fabricated with silicon-on-insulator (SOI) wafer by a newly-conceived wet etching process. Buffered oxide etchant (BOE, NH4F: HF = 6:1) solution with additives of octylamine and octanol was used for wet etching process in which the operating temperature was 50°C. Photoresist as a passivation layer was deposited on the upper side of SOI wafer to minimize strain gauge damage by chemical etchants. Small amount of octylamine and octanol were added to BOE solution to improve surface wettability and SiO2/Si selectivity. The fabricated strain gauges were attached to the pressure diaphragm and the performance of strain gauge was investigated by measuring with the hydraulic pressure system. The resistance changed linearly with tensile and compressive strains. Maximum values of non-linearity, hysteresis, thermal coefficient of resistance (TCR) and sensitivity were -0.341 %, 0.909 %, 4128 ppm/°C and 34.22 mV/V respectively. The fabricated strain gauges might be well applicable to the hydrogen pressure sensor which is detectable for high pressure range (0–900 bar).

Unshoring Process of a Temporary Pillar, in a Seventeen-Storey Building in Sant Adrià del Besós

In the new construction of a seventeen-storey building, a provisional prop of fourteen-meter height, horizontally braced on two intermediate levels, has been used. Despite the fact that structural logic suggests that it can be cut without having any added safety precautions, the structure of the building, made up of cores and reinforced concrete slabs working spatially, indicates that certain mechanisms be introduced so that, in the event that different and worse behaviors than expected are detected, the process can be stopped and the consequences of the new situation observed can be analyzed. For this purpose, two pairs of four metallic cantilevers were introduced at mid-height with four hydraulic pistons. In addition, the best position of a series of strain gauges as well as transducers were analyzed. At first, a load test was carried out to check that the brackets worked correctly. Once this step was verified, the abutment was cut, and the results were read. The results of stresses and deformations were compared with those expected, always being satisfactory. Finally, four provisional profiles were placed in case after a few days the structure suddenly gave way. The research focuses on obtaining an efficient control system and achieving total security throughout the process, with the comparison of the results strictly necessary for this case. Few resources were used so as not to make the work excessively expensive. We have found important divergences, on the side of security, between calculation and reality. We have also considered that the construction process has an impact on the final results. In the same way, the rigidity of the temporal abutment must be considered before the calculation. All these factors have generated a lower-than-expected deformation in an 8 m cantilever.

Numerical Simulation and Model Test on Pressure Fluctuation and Structural Characteristics of Lightweight Axial Flow Pump

In order to explore the relationship between the hydraulic performance, pressure pulsation, and structural characteristics of lightweight axial flow pumps, this paper takes the axial flow pump as the research object and analyzes pressure pulsation and structural characteristics by changing the blade length and thickness to realize the lightweight design of the axial flow pump impeller. Compared with the initial scheme (Scheme 1), the mass of the impeller is reduced by 17.2% (Scheme 2) and 29.9% (Scheme 3), respectively. The lightweight axial flow pump (Scheme 2 and Scheme 3) has a lower pressure pulsation amplitude at the impeller outlet monitoring point under large flow conditions. After the lightweight design of the axial flow pump impeller, the blade becomes shorter, the mass becomes lighter, and the cavitation performance will become worse. The maximum equivalent stress of Scheme 2 and Scheme 3 is increased by 2.8% and 31.9%, respectively, compared to Scheme 1. The maximum deformation of Scheme 3 increased by 27% compared to Scheme 1. This research can provide guidance for the lightweight optimization design of the axial flow pump.

A digital twin-assisted intelligent fault diagnosis method for hydraulic systems

As the complexity of modern engineering systems increases, traditional fault detection models face growing challenges in achieving accuracy and reliability. This paper presents a novel Digital Twin-assisted fault diagnosis framework specifically designed for hydraulic systems. The framework utilizes a virtual model, constructed using Modelica, which is integrated with real-time system data through a first-of-its-kind bidirectional data consistency evaluation mechanism. The integrated data is further refined using a two-dimensional signal warping algorithm to enhance its reliability. This optimized twin data is then employed to train a multi-channel one-dimensional convolutional neural network-gated recurrent unit model, effectively capturing both spatial and temporal features to improve fault detection. The subsea blowout preventer in lab is used to study the performance of the method. The results show that the accuracy is 95.62 %. Compared to current methods, this is a significant improvement. By integrating DT technology, data consistency optimization, and advanced deep learning techniques, this framework provides a scalable and reliable solution for predictive maintenance in complex engineering systems.

Analytical comparison of the boil-off gas recondensation process’s energy consumption and carbon emissions

With 28 operational liquefied natural gas receiving terminals in China by 2023, totaling a receiving capacity of 1.2 × 108 t/a, managing carbon emissions and boil-off gas has attracted increased attention. This study presents the optimization of 8 boil-off gas (BOG) recondensation processes, considering energy consumption and carbon emissions as assessment criteria, along with two types of vaporizers. The method involves analyzing how process parameters affect system performance using Hydraulic System Simulation Software, followed by optimizing system parameters with a genetic algorithm. It explores the impact of compressor output pressure, after-cooler inlet material ratio, and pre-cooler inlet material ratio on system energy consumption and carbon emissions. Results show that increased recondensing, compression, and cooling measures slightly elevate energy consumption but significantly reduce carbon emissions. Moreover, a higher BOG content enhances the carbon reduction effect. This study represents the first optimization of BOG recondensation processes focusing on carbon emissions, offering fresh theoretical insights and significant potential for enhancing energy efficiency and reducing carbon emissions.

Numerical analysis of impact resistance mechanical properties of energy-absorbing columns under static and dynamic loads

To enhance the impact resistance of hydraulic columns, a theoretical analysis method was employed to develop a dynamic characteristic analysis model for conventional columns under impact loads. This model facilitated the derivation of key parameters such as equivalent stiffness, maximum retraction amount, and impact duration. A fluid-solid coupling model for the conventional column was constructed using finite element and coupled Eulerian-Lagrangian (CEL) methods. Subsequently, numerical simulation results were compared and analyzed against theoretical predictions. Based on this analysis, an energy-absorbing column was designed, and its fluid-solid coupling model was established to investigate its mechanical response under static and dynamic impact loads.The findings indicate that under a static load of 2000 kN, when superimposed with impact loads of 200 kJ, 400 kJ, and 800 kJ respectively, the peak impact forces on energy-absorbing columns are 89.20%, 91.72%, and 98.42% lower than those on normal columns. The yield displacements of energy-absorbing columns increase by 142.26%, 109.15%, and 108.41% compared to normal columns. Energy absorption in energy-absorbing columns is 152.11%, 171.80%, and 145.18% higher than in normal columns. Furthermore, initial velocities of energy-absorbing columns are consistently lower compared to normal columns. After reaching initial velocity, energy-absorbing columns exhibit reduced oscillations due to interactions between the energy absorber, column, and hydraulic fluid system under impact loads. Unlike normal columns, energy-absorbing columns mitigate stress concentration at the column head through interactions between the energy absorber, emulsion, and column. Additionally, the impact resistance time of energy-absorbing columns is 2.19, 1.64, and 1.85 times longer than that of normal columns.Energy-absorbing columns outperform conventional columns across six metrics: peak impact force, column yield displacement, energy absorption, column movement speed, stress distribution, and impact resistance time, demonstrating superior mechanical properties in impact resistance.

Low-complexity tracking control of hydraulic excavator systems with asymmetric full-state constraints

This work is devoted to solving the control problem of hydraulic excavator systems under full-state constraints. The standout aspect of the proposed control approach lies in the fact that not only full-state constraints can be accommodated, but also the settling time and tracking precision can be explicitly specified in advance, irrespective of the arbitrary initial poses of the hydraulic excavator. Additionally, a novel nonlinear state-dependent function is introduced, enabling the system to handle a larger range of initial conditions. The proposed controller, which solely relies on the state variables after nonlinear transformation, has lower complexity in both structure and expression. The effectiveness of the proposed approach is demonstrated through simulations and experiments.

Bayesian model averaging and Bayesian inference-based probabilistic inversion method for arch dam zonal material parameters

Inversion analysis based on structural monitoring data is an important part of evaluating the working behaviour of structures. In this paper, a probabilistic inversion method for the elastic modulus of concrete in arch dams based on Bayesian model averaging (BMA) and Bayesian inference is proposed. According to the measured displacement data of an arch dam project, the influence of the separation accuracy of water pressure component, the inversion method and the selection of displacement measuring points on the inversion results of the elastic modulus of the dam body is studied. Example analysis results show that the accuracy of the multi-measurement point displacement and hydraulic pressure component separation model based on BMA-HST (Hydrostatic-seasonal-time) is at least 18.97 % higher than that of the single measurement point, and the relative error of the elastic modulus value of the multi-measurement point zonal inversion based on the Polynomial chaos-Kriging (PCK) proxy model and the Bayesian inference is only 6 % at the maximum, which indicates that the inversion model described in this paper is able to realize the high-precision inversion analysis of the material parameters of the zonal analysis of concrete dams at a relatively low computational cost.

Optimal shift control for new dual-clutch full-powershift transmission of heavy-duty tractor based on genetic algorithm–particle swarm optimization

The calculation of a linear quadratic regulator (LQR) control weighting matrix determines whether it can achieve optimal control. In order to solve the problem of complex calculation and low efficiency of this matrix, this paper proposed genetic algorithm–particle swarm optimizatio algorithm (GAPSO) combining genetic algorithm and particle swarm algorithm to solve the weighting matrix of LQR clutch oil pressure control strategy, so as to control the design efficiency and precision of the strategy. Subsequently, the shifting quality of a tractor was improved. A dynamic model of the shifting process was established using a comprehensive indicator that combined jerk and sliding friction work as a quadratic function. An LQR-weighted matrix calculated using GAPSO enabled optimal control strategy designing for clutch hydraulic pressure. Furthermore, the shift process from the 11th to 12th gear was analyzed via simulations during plowing operations. The simulation results show that the genetic operation of crossover and variation is introduced into PSO, and the optimization ability of PSO is improved effectively. Compared with the clutch oil pressure control strategy calculated by GAPSO with LQR weighted matrix and LQR clutch oil pressure control strategy calculated by PSO with LQR weighted matrix, the clutch heat load is slightly increased, the smoothness of shifting is greatly improved, and the shifting quality of tractors is improved. Overall, this study provides valuable insights for designing and computationally analyzing optimal clutch LQR control.

Solutions and case studies for thermally driven reactive transport and porosity evolution in geothermal systems (reactive Lauwerier problem)

Abstract. Subsurface non-isothermal fluid injection is a ubiquitous scenario in energy and water resource applications, which can lead to geochemical disequilibrium and thermally driven solubility changes and reactions. Depending on the nature of the solubility of a mineral, the thermal change can lead to either mineral dissolution or precipitation (due to undersaturation or supersaturation conditions). Here, by considering this thermo-hydro-chemical (THC) scenario and by calculating the temperature-dependent solubility using a non-isothermal solution (the so-called Lauwerier solution), thermally driven reactive transport solutions are derived for a confined aquifer. The coupled solutions, hereafter termed the “reactive Lauwerier problem”, are developed for axisymmetric and Cartesian symmetries and additionally provide the porosity evolution in the aquifer. The solutions are then used to study two common cases: (I) hot CO2-rich water injection into a carbonate aquifer and (II) hot silica-rich water injection into a sandstone aquifer, leading to mineral dissolution and precipitation, respectively. We discuss the timescales of such fluid–rock interactions and the changes in hydraulic system properties. The solutions and findings contribute to the understanding and management of subsurface energy and water resources, such as aquifer thermal energy storage, aquifer storage and recovery and reinjection of used geothermal water. The solutions are also useful for developing and benchmarking complex coupled numerical codes.

Digital indicator for evaluating the hydraulic control system of the tractor gearbox

The effi ciency of using energy-saturated tractors in agriculture largely depends on the level of preparation for fi eld work, which in turn depends on an objective assessment of the general technical condition of components and assemblies to justify the repair and maintenance work carried out. Various diagnostic tools are widely used for a non-selective assessment of the general technical condition of the internal combustion engine: motor testers, crankcase gas fl ow meters, etc. However, there are no such means to assess the technical condition of the transmission (gearbox) of energy-saturated equipment of domestic production. In conditions of logistical remoteness from service centers, there is a need to develop digital indicators to assess the general technical condition of a hydraulically controlled gearbox according to the time of the transition process, allowing the end user to contact the dealer’s service company in a timely manner (The purpose of the study) to study the status of the issue, analyze the NTD and search experiments and develop an experimental digital indicator for monitoring the general technical condition of boxes transmission changes of energy-saturated tractors of domestic production according to the transition process in the hydraulic control system. (Materials and methods) Conducted an analysis, studied the NTD, as well as methodological guidelines for diagnosing and managing the reliability of agricultural machinery, previously produced control and diagnostic equipment, KI-112383 was chosen as an analog for the development of a digital indicator. It has been established that the method of transient characteristics is widely used to diagnose rapidly changing processes. Monitoring the time of the transition process in the hydraulic control system is a necessary diagnostic procedure that allows you to indiscriminately assess the overall technical condition of the KP of operated energysaturated tractors. (Results and discussion) the results of staged experiments using the E-14-140M ADC when running in the gearbox of the K-744R tractor on the stand showed the possibility of a comparative assessment of the general technical condition according to the transient characteristics of pressure recovery in the control system during gear shifting. To develop a prototype of the digital indicator, a virtual simulation was carried out with simulation of the algorithms of operation, and test tests were carried out on the developed laboratory installation. The developed experimental digital indicator can be used as an integrated monitoring tool to automatically determine the general technical condition of the gearbox, as well as inform the operator to minimize the infl uence of the «human» factor when changing gears. (Conclusions) For eff ective management of the general technical condition of tractors, it is necessary to pilot the implementation of the developed digital indicator, which will allow assessing the dynamics of changes in the transient pressure recovery process as a diagnostic parameter during the repair of the gearbox and under operating conditions of tractors without making changes to the design.