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When conducting accelerated tests of transmissions and reducers of mobile machines, it is required to study the dynamic properties of the bench together with the test object installed on it. This is necessary to identify possible resonances in the oscillatory system and to select appropriate test modes, which exclude the occurrence of unacceptable levels of loads that violate the correspondence between the type and nature of damage in operation and during testing. The paper proposes a methodical approach to the calculational determination of the dynamic parameters (natural frequencies and natural modes of torsional vibrations) of the bench with a mechanically open loop during accelerated life tests of the two-row planetary motor-wheel reducers of BELAZ mining dump trucks, based on the study of the developed multi-mass dynamic model with lumped parameters. The calculation features consist in taking into account the existence of symmetry plane of the bench mechanical system with two reducers installed on it, as well as the presence of symmetrical branches in the planetary rows, formed by the masses of satellites rotating around their axes and elastic constraints connecting them with the sun and crown gears. The approach proposed makes it possible to significantly simplify calculations and to reduce the computation time.

Electromagnetic shock absorbers are mechatronic actuators designed to improve ride comfort and road holding in ground vehicles by introducing variable active and damping forces in the suspension. This feature difficults their testing, as the characterization test bench must adapt to this variable load feature. Moreover, there is interest in testing them under realistic use scenarios. In this context, this work focuses on a hardware-in-the-loop implementation on a custom damper test bench to characterize rotary electromagnetic shock absorbers. First, the used test bench is presented and described. The model of the plant is obtained together with a quarter car model of the target vehicle. Test bench bandwidth and instability issues are discussed. Then, a model following compensation method is proposed and simulated. Finally, the resulting approach is used to control the testbed, where the quarter car model is used to produce a realistic load duty cycle in real time. Experiments highlight the tracking performance of the test rig and its robustness against load variations.

In order to obtain the static strength of small modulus plastic gears, a small modulus plastic gear static strength test bench is developed, which can accurately measure the static strength of plastic gears under different modulus, speeds and materials. The working principle, constitution and the design of tooling parts of the test bed are mainly introduced. The test bench is composed of the mechanical system, the electric control system and the measuring software. The electric control system and the measuring software mainly adopt the horizontal structure, which is of the compact structure, with small space occupation, uses simple fixture design and is easy to measure. The static strength test is carried out, and the static strength using different materials is briefly tested. The experimental equipment can realize the measurement of the static strength of the small module plastic gear, which solves the problems of inaccurate static strength test of the small module gear and the difficulty of test clamping, and provides theoretical value and practical application value for the design of the plastic gear in the future.

Since electric power steering has replaced hydraulic power steering in passenger cars, steering feedback has become a challenging task in steering system development. Test benches represent a valid approach for improving steering feedback since they allow investigations without the real vehicle. To improve the applicability of feedback evaluations on a steering test bench, this paper aims to identify improvements in the current evaluation technique to obtain objective parameters that correlate with a subjective evaluation of safety-relevant steering feedback. Therefore, a previously reported approach of a chirp rack force excitation, using the magnitude of the transfer function from the rack force to steering wheel torque to describe steering feedback, is compared to a similar identification approach in which a pseudo-random-binary-sequence signal is utilized. To reflect realistic applications, driving maneuvers are transferred to the test bench to identify relevant objective data. For a valid representation of the steering wheel operation, a human grip model is implemented and compared to a fixed steering wheel angle control. It is shown that the random signal represents a valid and, on average, improved approach to objectively evaluating the steering feedback. Furthermore, a recommendation can be made to include the human grip model in the feedback evaluation tests, as the identified correlation results are improved by its inclusion. The identified parameters and methods represent an improvement for future steering feedback development.

The article presents an adaptation of the Gaevsky-Zhidkov method for estimating the balance of high-speed small-sized internal combustion engines using the idle characteristic, as well as propeller and external speed characteristics. The main task was to develop a test bench that provides high accuracy, repeatability of measurements and the ability to test internal combustion engines with working volume of up to 3.5 cm3 at shaft speeds of up to 37,000 rpm. The test bench makes it possible to determine the characteristics of the “engine-propeller”, the no-load characteristic, and also to carry out quick reconfiguration of the test facility when changing the internal combustion engine structure. As a result of the experimental study, the propeller characteristics of seven propellers, the no-load characteristics for the base electric motor and an electric motor with imbalance were determined. Using these results, the external speed characteristics of an internal combustion micro-engine with working volume of 2.5cm3 were compared for two levels of balancing.

Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible.Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature.Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed.Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.

The current paper presents the architecture of a test bench for small (laboratory) scale hybrid rocket motors destined for teaching purposes. The sustainability of the proposed methodology is emphasized, as it addresses the development of small-scale hybrid rocket motor test benches, to be used either as didactic means for students or for research laboratories, by using low-cost materials, while preserving efficiency. In this regard, the entire development process is approached, from designing to manufacturing (including the casting of the fuel rod) and testing of the product. The developed product uses a mixture of 88% paraffin, 10% stearic acid, and 2% coal for the solid phase and liquid oxygen for the liquid phase. The testing of the hybrid rocket motor demonstrator was performed outdoors, in controlled conditions. The results showed a good correlation between the theoretical testing parameters with the obtained ones.

The article discusses the key role of the use of automation in the stands, as well as the ignition system of the stand of low-thrust engines and the features of its operation as part of the stand. The ignition system scheme was developed, assembled and worked out, on the basis of which the ignition of the components of the propulsion system mixture will be carried out. The ignition system was tested by directly connecting the power supply to the circuit, which during the tests showed its suitability for use due to the long and continuous operation of the system. The power was turned on by controlling relay switches based on the Arduino MEGA 2560. Also, an algorithm was developed for the operation of the automation system for switching on, off and checking the entire system before testing the propulsion system on the stand of low-thrust engines to ensure automation and safety of using the stand. This algorithm includes control of two channels of the oxidizer and fuel pipeline, emergency power off, opening and closing of cut-off valves, taking readings and checking pressure gauges and flow meters, as well as shutting down the system after testing low-thrust engines using an Arduino MEGA controller.

The present paper is focused on designing and manufacturing a remote-control test bench for RPA's brushless motors. The main components of the testing bench (structural, mechanical and electric components) are presented, how they are coupled, and the operating principle. The test bench is characterized by five emergency systems, one manual and four automated emergency systems that can stop the test under different conditions to avoid damaging the motor. To validate the testing bench, a SK3-5045 660 kV electric motor was selected along with a carbon fibre reinforced composite propeller. It was experimentally demonstrated that the test bench was fully automated, there were measured the propulsion force, current intensity, voltage, but also the consumed power of a motor intended for an RPA. The test results were used to determine the motorization performance and power consumption of an RPA designed with four electric motors (quadcopter type).

In order to study the energy distribution of the tandem hybrid tractor and achieve optimal fuel economy under the whole operating condition, an energy distribution strategy based on PMP (Pontryagin minimum principle) is proposed. The performance parameters of the relevant power components are obtained by constructing the test bench of the tandem hybrid tractor. At the same time, the mathematical model of energy distribution is established from the aspects of energy distribution objective function, state variable, and variable constraint. Based on the external characteristic test of the hub motor and the resistance analysis, the transport operation condition of the tractor is selected as the simulation target condition. The ADVISOR2002 and Simulink software are used to jointly simulate the three energy distribution strategies: the thermostat type, the power-following type, and the PMP type. The simulation results show that, compared with the other two, the fuel economy and battery power loss of the PMP-based energy distribution strategy are significantly improved. The fuel consumption per 100 km is decreased by 32.91% and 26.10%, respectively, which verifies the feasibility of the strategy. This study is of great significance for improving the production efficiency and reducing fuel consumption of hybrid tractors.

The increasing interest in the use of renewable energy technologies is directing attention towards the potential contribution of marine energy technologies, especially ocean wave energy, to world energy demand. While open-sea demonstrations of full-scale devices have been carried out to validate several technologies, the focus now is shifting to optimising the components for efficiency and reliability. The efficiency of the electrical generator plays a crucial role in wave-to-wire numerical models for converting wave energy into usable electricity. It provides essential data that enables the industry to reduce technical risks and uncertainties. Wave-to-wire models typically simplify the generator’s efficiency through assuming a single curve based on the load. This curve is usually provided by the machine manufacturers for the nominal rotational speed. However, the rotational speed varies in the case of air turbines used in OWC devices. Therefore, to accurately estimate decision variables derived from these models, a comprehensive efficiency map is necessary. This map should demonstrate the performance at different rotational speeds and loads, as it directly influences the estimation of key parameters. The main objective of the present work is to improve the generator behaviour of an OWC for different generator operation regimes. For this purpose, a numerical model of the generator’s efficiency will be developed throughout the segregation of losses and validated experimentally. Finally, an optimal control law will be presented to maximise the electrical power output of the wave energy converter, considering the efficiency of both the generator and the turbine.

Volumetric hydraulic drive systems are quite widespread in many industrial sectors. To determine the degree of reliability of hydraulic machines, it is necessary to conduct resource tests. The main requirement for such tests is the compliance of the load level with the operating mode of the hydraulic machine. Analysis of existing methods of creating such a load showed a significant drawback of bench tests—the lack of useful work. Therefore, a number of authors suggest the use of stands with a regenerative drive system. One peculiarity of the work of such stands is the possibility of returning part of the spent energy back to the test system. However, such systems are insufficiently studied and have significant drawbacks. The purpose of this work is to increase the efficiency of the regenerative drive system of the test bench of volumetric hydraulic machines of rotational action by improving the theory and methodology of its calculation and design. This article describes the principle of operation of the circuit of the regenerative drive of the test bench of rotary hydraulic machines. A model of the elastic-dissipative state of the sections of the elements of the hydro-mechanical drive system of the stand is also proposed, which allows for the calculation of the structural and energy parameters of the regenerative hydro-mechanical system. The main structural and functional parameters affecting the operational performance of the system as a whole are also identified. A “test efficiency coefficient” is proposed, which allows for evaluation of the energy efficiency of the test process.

In recent years, applications exploiting the advantages of tilt-rotors and other vectored thrust propulsion systems have become widespread, particularly in many novel Vertical Takeoff and Landing (VTOL) configurations. These propulsion systems can provide additional control authority, enabling more complex flight modes, but the resulting control systems can be challenging to design due to the mismatch between the vehicle degrees of freedom and physical input variables. These propulsion systems present both advantages and difficulties because they can exert the same overall forces and moments in many different propulsive configurations. This leads to the traditional non-uniqueness problem when using the inverse dynamics control allocation approach, which is the basis of many popular VTOL control algorithms. In this article, a modified Planar VTOL (PVTOL) test bench configuration, which considers an arbitrary number of co-linear tilting rotors, is introduced as a benchmark for the study of the control allocation problem. The resulting propulsion system is then modeled and linearized in a closed and compact form. This allows a simple and systematic derivation of many of the currently used control allocation approaches. According to the proposed PVTOL configuration, a two-rotor test bench is implemented experimentally and a decoupling control allocation strategy based on Singular Value Decomposition (SVD) analysis is developed. The proposed approach is compared with a traditional input mixer algorithm based on physical intuition. The results show that the SVD-based solution achieves better cross-coupling reduction and preserves the main properties of the physically derived approach. Finally, it is shown that the proposed PVTOL configuration is effective for studying the control allocation problem experimentally in a controlled environment and could serve as a benchmark for comparing different approaches.

Quantifying rowing performance can facilitate control of training load or assessment of skill level. Accordingly, the FlexOmega system was developed, which records the bending moment of the oar. This work aimed to validate this new instrumentation during a dynamic load case. Two force profiles were first derived from bending moments acquired during on-water rowing (one at race pace, one at training pace). These force profiles were then used to repeatedly load the instrumented oar on a newly developed test bench. To ultimately elaborate how precision and accuracy determined on the test bench affects everyday training, i.e., whether practitioners can reasonably use the FlexOmega system, the measurement variability observed on the test bench was related to the measurement variability seen for on-water measurements. On the test bench (featuring a mean precision of 99% and mean accuracy of 95%), a mean error of 3 Nm (mean precision: 98%, mean accuracy: 97%) was determined for the FlexOmega system for the force profile A characterised by bending moments of up to 300 Nm (racing simulated, 37 strokes per minute). For the force profile B with lower stroke rate and less force (21 strokes per minute, up to 150 Nm), the mean error was 2 Nm (mean precision: 98%, mean accuracy: 97%). The measurement variability observed on the test bench was on average for the two force profiles 30% (profile A) and 15% (profile B) of the measurement variability that occurred during on-water rowing. We conclude that improving the measurement characteristics of the instrumentation would hardly result in any practical benefit as on-water measurements seem mainly to be influenced by the rower’s skill level and environmental condition. Thus, the FlexOmega system can be used to control training intensity or to evaluate rowing performance. In addition, the presented approach for elaborating measurement characteristics could contribute to.

Aspiration catheters play an important role in mechanical thrombectomy in interventional neuroradiology as they provide support for stent retrievers or are increasingly used separately for contact aspiration. To evaluate the performance of different aspiration catheters in terms of suction force, most current studies rely on manual measurement methods or the suction force is not measured close to the aspiration catheter tip. Moreover, there is currently no standardized method that records measurements digitally and with high temporal resolution. To overcome these challenges, we propose a new test bench that simulates a dedicated aspiration scenario and takes measurements close to the aspiration catheter tip. To meet the requirements, a simplified vascular phantom, a pressure sensor and a simplified clot model were implemented in the prototype. To demonstrate the applicability of the prototype, two commonly used aspiration catheters were evaluated. The obtained measurements show that it is possible to perform standardized comparisons between aspiration catheters from different manufacturers as well as different aspiration pumps and aspiration tubings and their combinations. The developed prototype overcomes the still widely used manual and semimanual and thus error prone measurement methods for the evaluation of vacuum based thrombectomy systems.

Shorter development times, increased standards for vehicle emissions and a greater number of vehicle variants result in a higher level of complexity in the vehicle development process. Efficient development of powertrain and driver assistance functions under comparable and reproducible operating conditions is possible on vehicle test benches. Yet, the realistic simulation of real driving environments on test benches is a challenge. Current test procedures and new technologies, such as Real Driving Emission tests and Autonomous Driving, require a reproducible and even more detailed simulation of the driving environment. Due to this, the simulation of curve driving in particular is gaining in importance. This results from its significant influence on energy consumption and Autonomous Driving functions with lateral guidance, such as lane departure and evasion assistance. Reproducibility can be additionally increased by using a driving robot. At today’s vehicle test benches, pedal and shift robots are predominantly used for longitudinal dynamic tests in the performed test procedures. In order to meet these new test automation requirements for vehicle test benches, the cooperative operation of pedal and steering robots is needed on a test bench setup suitable for this purpose. In this publication, the authors present the setup of a vehicle test bench to be used in automated and reproducible vehicle-in-the-loop tests during steering events. The focus is on the test-bench-specific setup with steerable front wheels, the actuators for simulating the wheel steering torque around the steering axle and the robots used for pedals and steering wheel. Results from various test series are presented and the potential of the novel test environment is shown. The results are reproducible in various test series due to the closed-loop operation without human driving influences at the test bench.

The regeneration of highly dynamic driving maneuvers on vehicle test benches is challenging due to several influences, such as power losses, vibrations in the overall system that involves the vehicle with the test bench, uncertainties in the model parameterization, and time delays from both the test bench and the measurement systems. In order to improve the dynamic response of the vehicle test bench and to overcome system disturbances, we employed different types of control algorithms for a mechanical multi-mass model. First, those controllers are extensively investigated in the frequency domain to analyze their stability and evaluate the noise rejection quality. Then, the expectations from the frequency analysis are confirmed in a time-domain simulation. Furthermore, sensitivity analysis tests were conducted to evaluate each controller’s robustness against the modeling parameters’ uncertainty. The linear quadratic controller with integral action demonstrated the best compromise between performance and robustness.

For the investigation of new types of internal gear pumps under realistic conditions, a test bench is presented that enables dynamic load emulation via the pressure with simultaneous dynamic speed control of the pump. For pressure control, a hydraulic half-bridge with separate control edges is used on both sides of the pump and a pressure control is presented. An error-based adaptive controller is used for pressure control and tested experimentally. It is shown that the error-based adaptive controller has a better performance compared to a simple PID control.

Introduction. The article describes the test bench specialized software, developed for technical inspection of domestic and foreign volumetric hydraulic drives in repair enterprises and service centers. The results of bench tests using a hydraulic bench and software are presented. Materials and Methods For the application software development, G graphical programming language of the Laboratory Virtual Instrumentation Engineering Workbench (Lab- View) programming environment developed by the National Instruments Company has been used. The reliability of the results obtained has been confirmed by a series of bench tests of domestic and foreign volumetric hydraulic drives. Results. There has been developed and implemented new test bench software for the technical inspection of hydraulic drives of different models from domestic and foreign manufacturers in repair plants and service centers. The software is used to capture, process and store data from the sensors during testing, to calculate and output measurement data, to conduct nonlaboratory analysis of the testing process in graphical, textual and video formats, to calibrate sensors, and to store the test results in the electronic library system. The specialized software runs under the Microsoft Windows 7 x86 (32-bit) operating system and is installed on a personal computer of the hydraulic bench data processing unit. The developed software is characterized by the ergonomics of the user interface, the ability to control all the parameters of diagnosing the tested volumetric hydraulic drives. Discussion and Conclusion. Specialized software and the test bench permit high accurate monitoring of all technical condition parameters of the most common domestic and foreign volumetric hydraulic drives in accordance with the requirements of the manufacturers in the repair enterprises and service centers.

This paper proposes a novel circuit configuration for a high-voltage direct-current circuit breaker (HVDCCB) test bench that differs significantly from conventional test benches. The proposed test bench consists of a modular multilevel cascaded converter (MMCC) that is based on H-bridge cells, an output inductor, and an auxiliary capacitor bank. The proposed test bench is capable of generating controllable output currents up to several kiloamperes and output voltages up to several hundred kilovolts because each MMCC cell is operated by phase-shifted pulse-width-modulated (PSPWM) signals. Consequently, the proposed test bench can simulate a wide range of fault conditions within hardware limitations to test different HVDCCB types with various current and voltage ratings. The flexibility of the proposed test bench is complemented by a longer service lifetime with inherent circuit protection in the case of operational failure of the HVDCCB. The concept of the proposed test bench is verified experimentally on a downscaled test bench that consists of nine H-bridge cells and operates at an equivalent switching frequency of $\mathrm {92.5 kHz }$ .

Electro-hydraulic suspension systems are one of the key working systems of tractors. Due to the complex and changeable working conditions in the field, it is of great significance to shorten the development cycle of the control strategy and reduce the development cost by using the indoor bench for test verification at the beginning of the study. Based on this, this paper has proposed a complete set of tractor hydraulic-suspension tillage-depth and loading-control test-bench designs. The system was mainly composed of three parts: an industrial computer, a suspension electro-hydraulic control system, and a loading electro-hydraulic control and data-acquisition system. The human–computer interaction interface of the test-bench measurement and control system was built, and the loading-force control system and suspension tillage-depth and loading integrated-control system were built based on PID and fuzzy PID control algorithms, respectively. The system can realize the control of suspension tillage depth and loading during the operation process and has the functions of the real-time acquisition, display, and data storage of related sensor signals during the working process. The test results showed that the response time of the loading-control system was less than 1.2 s, and the maximum steady-state error was less than 0.8%. The response time of the suspension control system was less than 2.3 s, and the maximum steady-state error was less than 1%. The system has good responsiveness and stability. These research results can provide platform and method of support for the development and test of tractor electro-hydraulic suspension systems.

In recent times, hydroponics has gained popularity as a viable solution to the challenges facing traditional agriculture, as it offers an environmentally friendly option with higher crop yields and improved quality, eliminating the need for soil. Despite these benefits, hydroponics still encounters significant difficulties, particularly in optimizing fertigation strategies. The literature contains several studies focusing on test benches for investigating technological recommendations related to fertigation strategies. However, there has been no proposed test bench capable of simultaneously exploring various types of fertigation strategies. In this work, HydroLab is introduced: a hydroponic module that allows for the simultaneous comparison of two types of fertigation strategies and enables remote monitoring and control through IoT functionality. Additionally, HydroLab’s potential to generate technological recommendations has been validated through a case study comparing time-based and solar radiation-based fertigation in lettuce cultivation. The case study successfully showcases the capability of HydroLab to investigate and compare different fertigation strategies. Given the global importance of food security challenges, this work is expected to contribute to the investigation of fertigation strategies in hydroponics.

Hybrid fuel cell powertrains are a promising strategy to reduce the environmental impact of vehicles and non-road mobile machinery. To preserve the state-of-health of fuel cells, an energy storage system with sufficient power capacity, such as ultra-capacitors or batteries, should be introduced in the system to help the fuel cell during sudden and abrupt changes in power demands. However, the presence of two or more energy sources necessitates the development of an energy management strategy. The energy management strategy should properly split the power request between the different energy sources. In this paper, the design and the experimental validation of a scaled test bench for the emulation of a fuel cell/battery powertrain for a vehicular application is presented. The fuel cell is emulated through an analogically controlled DC power source that reproduces its real voltage–current curve. To split the power between the emulated fuel cell and the batteries, controlled DC-DC is used and a simple energy management strategy based on a proportional-integral controller is developed. The external load is reproduced using a load unit composed of a programmable electronic load and a power supply. Experimental tests are performed to evaluate the system behaviour and to characterize its main components. The experimental results show that the system successfully emulates the powertrain in accordance with the proposed energy management strategy.

Abstract Background Clinical diagnostics of whole-exome and whole-genome sequencing data requires geneticists to consider thousands of genetic variants for each patient. Various variant prioritization methods have been developed over the last years to aid clinicians in identifying variants that are likely disease-causing. Each time a new method is developed, its effectiveness must be evaluated and compared to other approaches based on the most recently available evaluation data. Doing so in an unbiased, systematic, and replicable manner requires significant effort. Results The open-source test bench “VPMBench” automates the evaluation of variant prioritization methods. VPMBench introduces a standardized interface for prioritization methods and provides a plugin system that makes it easy to evaluate new methods. It supports different input data formats and custom output data preparation. VPMBench exploits declaratively specified information about the methods, e.g., the variants supported by the methods. Plugins may also be provided in a technology-agnostic manner via containerization. Conclusions VPMBench significantly simplifies the evaluation of both custom and published variant prioritization methods. As we expect variant prioritization methods to become ever more critical with the advent of whole-genome sequencing in clinical diagnostics, such tool support is crucial to facilitate methodological research.

Radial shock wave therapy is used for different therapeutic indications. In order to assess the effect on the treated tissue, it is important to know the sound field parameters. However, it is challenging to measure the pressure curves of ballistic devices, especially at high pulse repetition rates. In the new standard IEC 63045:2020 two possibilities for sound field measurements of non-focusing devices are described, a wet and a dry test bench. The whole sound field can be characterised using a wet test bench, but the process is cumbersome and cavitation is likely to occur at high pulse repetition rates. This effect is avoided using a dry test bench where the measurement position is limited to a single spot. Therefore, a hybrid test bench was developed combining the dry bench’s device mounting and coupling with a small water basin. The ballistic device was coupled to the basin filled with degassed ultrapure water using a latex membrane covered with ultrasound gel and the contact pressure was applied with a spring. A fibre optic probe hydrophone was used for the sound field measurements. The pressure curves of every 10th shot were measured on the beam axis in a distance of 1mm to the membrane. The device was analysed at 3.5 bar with different pulse repetition rates (1 Hz, 10 Hz, 20 Hz). The test setup enables an easy handling and reproducible results at all pulse repetition rates. The ballistic device provides constant peak pressures over different frequencies. The small water basin has the advantage that the water quality is easy to control and the measuring process is fast and uncomplicated. Cavitation suppression requires a clean water basin filled with degassed ultrapure water kept at a constant, low temperature. The hybrid test bench can be used to easily study shock wave parameters of ballistic devices at high repetition rates.

The door is an important part of the aircraft structure.The door test is an important means to verify that the door design meets the requirements of reliability,safety and airworthiness.There are design verification tests and certification tests for doors of civil airplane.Based on the experience and lessons of civil airplane doors′development,the necessary test items and contents during the civil airplane doors′developing process are summarized in this paper.The purpose,significance and necessity of each test are pointed out,the design of test benches and the simplified designing principle of test-pieces are proposed,and the methods and steps of the tests are given.The research in this paper has certain reference value for the door design to meet the requirements such as function and performance,use requirements,continuous airworthiness requirements and to formulate a reasonable test plan in the design stage.

This project deals with the realization of Mathematical Modeling and simulation in MATLAB of Differential Protection in Two-Winding Power Transformers, the same one that will be part of the Salesian Polytechnic University, Guayaquil headquarters; will have the objective of simulating the operating conditions of the protection equipment (SEL 587) found in a Substation, obtaining the equation that governs the differential protection operations of said relay, by theoretically analyzing the system conditions, both under normal conditions and for any fault event (external fault, internal fault) on the primary and / or secondary side of the transformer, facilitating students who are in the last cycles of the Electrical Engineering career, learning the concepts and principles of operation of System protections Electric Power.

The present study deals with the development of a test cycle for the centrifugal clutch of continuously variable transmission (CVT) driven scooters. Centrifugal clutch experiences different duty cycles during the usage of scooters in city traffic and highways during its lifetime. Since the friction characteristics of the centrifugal clutch are controlled by acquired factors, it is difficult to predict ideal friction characteristics under all conditions. The wear of friction lining increases due to heat generated in the clutch assembly because of the repeated “stick-slip” phenomena. Therefore, an attempt has been made for developing à new test cycle by keeping the engagement frequency as a reference. Road load data for three different riding conditions have been collected and analyzed. The developed test cycle has been automated on the centrifugal clutch test bench and a new set of clutch liners was tested thoroughly. The surface roughness, thickness, and wear of clutch liners have been observed and evaluated against the field vehicles. For the surface roughness, maximum deviations of 3.74%, 3.36%, and 2.16% have been observed for trailing, middle and leading sections of clutch liners respectively. For the thickness, maximum deviations of 3.06%, 2.59%, and 3.14% have been observed for trailing, middle and leading sections of clutch liners respectively. The developed test cycle demonstrates a good correlation with field use.

Recently, a significant amount of research has been devoted to soft robots. Artificial muscles belong to the most important components of soft robots. Dielectric elastomer actuators (DEAs) represent the technology that comes closest to the capabilities of a natural muscle, making them the best candidates for artificial muscles in robotics and prosthetics applications. To develop these applications, an analysis of DEAs in a test bench must be possible. It is important that the environmental conditions are known, and all components are specified, which is not the case in most publications. This paper focuses on the development of a real-time test bench for DEAs which provides environmental conditions and all components that are specified. Its goal is to open up the research field of dielectric elastomer actuators or soft robots. The stacked DEA used is powered by a high-voltage amplifier, which can be controlled via a real-time block diagram environment together with a data acquisition (DAQ) device. The response of the actuator is measured with a laser triangulation sensor. Furthermore, information about the applied voltage, the operating current, the temperature, and the humidity are collected. It was demonstrated that the selected laser sensor is a suitable device for this application. Moreover, it was shown that the selected high-voltage amplifier is adequate to power a DEA. However, the DAQ is not fast enough to measure the actuator current. It was demonstrated that housing keeps environmental conditions constant, is transportable, and offers the flexibility to investigate different DEAs.

In this study, we quantified and analyzed the root-cutting process of garlic with a test bench with pressure sensors on the basis of the comparative analysis of various information perception methods. On the basis of the output value of the pressure sensor, the force curve of garlic roots was plotted, and the double round blade cutting module is optimized on the basis of the force curve diagram. The innovative proposal of slotted round blades for garlic root cutting is presented here. The round blade diameter is 110 mm, the center distance is 100 mm, the blade thickness is 1 mm, and the blade speed is 1200 r/min. According to the analysis of the force curve, it was found that the slotted round blade with the slanted blade could generate a strong thrust to cut the roots. The cutting effect was better and the cutting surface of the roots was straight. The slotted blade meets the need for cutting garlic roots.

The increasingly stringent CO2 emissions standards require innovative solutions in the vehicle development process. One possibility to reduce CO2 emissions is the electrification of powertrains. The resulting increased complexity, as well as the increased competition and time pressure make the use of simulation software and test benches indispensable in the early development phases. This publication therefore presents a methodology for test bench coupling to enable early testing of electrified powertrains. For this purpose, an internal combustion engine test bench and an electric motor test bench are virtually interconnected. By applying and extending the Distributed Co-Simulation Protocol Standard for the presented hybrid electric powertrain use case, real-time-capable communication between the two test benches is achieved. Insights into the test bench setups, and the communication between the test benches and the protocol extension, especially with regard to temperature measurements, enable the extension to be applied to other powertrain or test bench configurations. The shown results from coupled test bench operations emphasize the applicability. The discussed experiences from the test bench coupling experiments complete the insights.

One of the most important problems of modern mechanical engineering is the energy efficiency of technological equipment and manufactured products. A separate issue in this series is the technology and means of testing finished product samples, including hydraulic machines. In this article, an original scheme of a test bench for piston hydraulic cylinders and a method of mathematical modeling of the process of its functioning, based on the application of the theory of volumetric rigidity of hydraulic systems, is proposed, which makes it possible to describe with high accuracy and reliability the processes occurring in the test system during its operation. The test efficiency coefficient is proposed, which makes it possible to evaluate and compare various test processes by the criterion of their energy efficiency. An example of a preliminary calculation of the functioning of the proposed stand is given.

In the past decade, an unmanned aerial spraying system (UASS) was applied more and more widely for low-volume aerial pesticides spraying operations in China. However, UASS have a higher drift risk due to more fine droplets sprayed with a higher working height and a faster driving speed than ground sprayers. Study on UASS spray drift is a new hot spot within the field of pesticide application technology. The field test bench was originally designed and applied for the measurement of the spray drift potential of ground sprayers. No methodology using the test bench for UASS drift evaluation was reported. Based on our previous study, field drift measurements of an eight-rotor UASS were conducted using three techniques (test bench, ground petri dish, and airborne collection frame) in this study, and the effects of meteorological parameters and nozzle types were investigated, to explore the applicability and the feasibility of the test bench used in UASS field drift evaluation. The test bench is proven promising for direct drift determination of UASS and the described methodology enabled classification of different UASS configurations. Higher wind speeds and finer droplets produced higher drift values. The faster the wind speed and the lower the humidity, the more the spray drift. The test bench can reduce the site requirements and improve the efficiency of the field drift test.

Aiming at the test requirements of integrated electric drive axle for light commercial vehicle， the test bench of integrated electric drive axle for light commercial vehicle is designed. The test methods suit for integrated electronic drive axle are established refer to traditional drive axle and electric motor test methods. By using the developed test bench and established test method， the performance and fatigue tests of the integrated electric drive axle are finished. It provides test technology support for design and manufacture departments.

The article presents the results of comparison of experimental studies and mathematical modeling of the stand for testing induction motors by the method of mutual load. A detailed description of the composition of the experimental equipment, which is based on a pair of frequency converters and connected to them a pair of engines of the АИС71В4 type with a nominal power of 0,75 kW, the shafts of which are rigidly connected by a coupling. The mathematical model of the electromechanical system used in the calculations is presented, and its main assumptions are listed. A table of parameter values and graphs obtained from calculated and experimental data are presented. The analysis of the obtained data shows the possibility of using the considered mathematical model with the existing assumptions in the design of electrical complexes intended for testing induction motors by the method of mutual load.

Nowadays, instrumentation involves remote control and test benches automation, because of the required accuracy or to guarantee the safety of the operators. In parallel, open source has known a fast expansion, and has helped scientific communities in industry and research to build strong collaborations to design effective and user-friendly software tools. This paper presents R-testbench, an open source Python library that offers high-level programming capabilities for instrument remote control and test bench automation. Comparatively to well-known off-the-shelf software solutions, it has been designed to be open source, reliable, adaptable and user-friendly. It relies on the Virtual Instrumentation Software Architecture (VISA) standard, and enables high-level features, including automatic instrument recognition, thanks to the object-oriented paradigm. It works with PyVISA, a Python front end that calls the VISA libraries, and uses the popular NumPy and pandas packages to offer an optimized data management that is efficient regarding the execution time and the memory use. The proposed library has been validated thanks to continuous integration, performance characterization, and alpha tests in the frame of experiments with nuclear material. It has also been released publicly on the GitHub platform, under the Open Software License 3.0, to be shared with and reviewed by the community.

Context: The Colombian Army’s First Aircraft Maintenance Battalion must periodically test the performance of Generator Control Unit (GCU) on its Beechcraft King Air aircraft, which compels the operator to assume uncomfortable and non-ergonomic physical positions. This article proposes the use of a portable digital troubleshooting test bench for these units that facilitates the taking of measurements, the interpretation of the acquired information, and the technical reports. Method: The Integrate, Innovation, Process model (IIP) for the development of aviation technology innovation projects was used to design the test bench. Then, its functional modules were defined, and voltage and impedance measurement devices, an internal report storage system, and the user interface were included. Tests were conducted together with technical operators on the available Beechcraft King C-90, 200, B 200, 300, and 350 series aircraft. Finally, a technical report was elaborated to validate the test bench results. Results: The number of operators required to carry out the tests was reduced from four to one. The digital test bench only requires the connection of measurement harnesses by the operator, so it allows an improvement in ergonomics for the personnel. Using the bench, the review and evaluation time of the GCU was reduced from 120 minutes to 26 minutes, which implies an 86,66% decrease in fuel consumption. Conclusions: By using the digital troubleshooting test bench, the number of operators needed and the checkup and assessment times of the GCU were reduced, which means a decrease in fuel expenses. Its ease of transportation allows aircraft to be checked outside the Maintenance Battalion hangars, but the implementation of a USB port to store the reports should be considered. Acknowledgments: We would like to thank the First Aircraft Maintenance Battalion of the Colombian National Army and the Aviation School for their contribution to the development of the prototype. This project was funded by the National Army of Colombia, Science of Science and Technology, under internal code No. 118315.

The induction motors (IMs) are undoubtedly the most used machines in industries because of the advantages they offer such as simplicity, service continuity and low cost. Due to wear and tear, the motor suffers different types of mechanical and electrical failures. Depending on the criticality of the plant motors, it could be necessary to implement predictive techniques in order to detect the faults before they can cause unnecessary downtime. Therefore, in this paper, the research approach was to develop a low cost measurement system based on a micro controller platform for machine diagnosis. The FRDM K64F developing board was selected as the most suitable for satisfying the system conditions, and it was used to collect induction motor`s current data. In order to validate the accuracy of the developed system, the Frequency Transfer Functions (FRF) of the developed measurement system and the standard system (NI USB-6009) were compare. It showed a flat frequency spectrum from 0 to 1 KHz, with small fluctuations of about 0.25 dB standard deviation. A fully automated test bench was implemented, which allows to perform all the measurement tests with the IMs, and in this case, the detection and diagnosis of broken bars. Around 240 tests were performed with varying loads, different rotation speeds, and with different severity damage levels in the rotor. The data analysis procedure for broken rotor bar detection and motor diagnosis was performed by the Motor Current Signature Analysis (MCSA), FFT and Enveloped Analysis (EA). Finally, the research approach was successfully accomplished, by the team by developing a software firmware measurement ultra-low cost development platform for machine diagnosis. It was also developed a proper antialiasing filter to reduce industrial noise. The effectiveness of the proposed system is detecting a weak fault in a noise signal. It was found out a new consistent and robust parameter called the pole pass frequency (fpsf), which could be used as a diagnosis parameter for detection of broken rotor bars faults, with their damage severity degree. The detected parameter can be found around 2.6 Hz, and it increases in amplitude with increasing damage severity.

For the control of dynamic systems such as an Electro-Hydraulic Actuator (EHA), there is a need to optimize the control based on simulations, since a prototype or a physical system is usually not available during system design. In consequence, no system identification can be performed. Therefore, it is unclear how well a simulation model of an EHA can be used for multicriteria optimization of the position control due to the uncertain model quality. To evaluate the suitability for control optimization, the EHA is modeled and parameterized as a grey-box model using existing parameters independent of test bench experiments. A method for multi-objective optimization of a controller is used to optimize the position control of the EHA. Finally, the step responses are compared with the test bench. The evaluation of the step responses for different loads and control parameters shows similar behavior between the simulation model and the physical system on the test bench, although the essential phenomena could not be reproduced. This means that the model quality achieved by modeling is suitable as an indication for the optimization of the control by simulation without a physical system.

The power take-off (PTO) of a wave energy converter (WEC) converts mechanical power extracted from the waves into electrical power. Increasing PTO performance under several operational conditions is therefore essential to reduce the levelized cost of energy of a given wave energy concept and to achieve higher levels of technology readiness. A key task in the WEC design will then be the holistic assessment of the PTO performance in combination with other subsystems. It is hence important that WEC designers are aware of the different modeling options. This paper addresses this need and presents two alternative wave-to-wire modeling approaches based on a 250 kW modular electromechanical PTO coupled to an oscillating wave surge converter (OWSC) device. The first is a detailed and accurate offline model. The second model is a simplified and faster version of the first, being adequate for rapid analyses and real-time (RT) simulation. The paper presents the benchmarking of the offline model against the RT model and the hardware-in-the-loop (HIL) tests of the PTO. The normalized root-mean-square error (NRMSE) is considered as a quantitative indicator for the measurement of real-time and HIL test results against the offline simulation. Results show that the dynamics of the offline model are well represented by the RT model with execution times up to 10 times faster. The offline model also depicts well the behavior observed in the HIL tests with the NRMSE values for the PTO position, velocity, and force above 0.90, which shows the HIL test results replicates with fidelity the dynamic behavior of the complete model. Meaningful differences are however present and highlighted in this paper. An understanding of the advantages and drawbacks of these three approaches is fundamental to properly design a WEC during its project cycle and validate PTO concepts with a certain level of simplification.

Introduction− Given the research potential currently presented by internal combustion engines, a complete characterization of their operating conditions requires taking into account the variety of sensors used to mea-sure their physical magnitudes, the multiple electronic devices used for the conditioning of signals and the stan-dards that define the communication syntax and syn-chronization. For this reason, it is necessary to develop software as a link between the instrumentation system and the user, to provide real-time visualization and stor-age of information.Objective− This study seeks to implement a methodol-ogy for the selection and adjustment of the data acqui-sition system for a Diesel engine test bench, as well as software developed to visualize the variables measured by the instruments.Methodology− The selection of the instruments used in the test bench was carried out, as well as the design of the signal treatment devices for each instrument, fol-lowed by set-up and calibration. Parallel to the above, interactive software was developed in a DAQ ́s for the visualization of the results obtained with the acquisi-tion system.Results− The results indicate that the developed cali-bration curve produces a considerable fit of the experi-mental data, and using residue analysis it was verified that the linear model developed was adequate to describe the behavior of the sensors.Conclusions− It was evidenced that 2 of the 7 of the sensors had uncertainty values lower than the measure-ment unit, which guarantees small or practically negli-gible deviations from the nominal value. Of the 7 types of instruments implemented, the sensor corresponding to the rotation speed presented the highest value of un-certainty; however, this value is adjusted to the errors allowed in the RPM measurements, which oscillates 5 % of their nominal value.

This article deals with the issues of an objective assessment of the technical condition of asynchronous motors with voltage up to 1000 V. A stand is proposed for post-repair tests. Test stand allows you to conduct induction motor tests to form an objective conclusion about the technical condition and quality of the repair carried out automatically.

In recent years, the technology of automatic tractor navigation based on satellite positioning has greatly improved the efficiency and accuracy of tractor field work. Automatic steering contributes is one of the key technologies to realize the automation and intelligentization of agricultural mechanization. It costs much time to install and test automatic steering systems for tractors in the field due to complicated conditions. An automatic steering test bench was developed to reduce time consumed in the field by conducting simulation tests on accuracy and reliability. The developed automatic steering system can be applied to the tractor after obtaining satisfactory results on the test bench, which will greatly shorten the development cycle and improve the precision of the system. In this study, a 120-horsepower tractor front axle was selected. Through the design and calculation of mechanical structure, hydraulic system and electrical control system, the tractor automatic steering test bench was built. The mechanical body consist of a tractor front axle assembly, a loading device and a mechanical frame. The hydraulic interface was reserved for post-installation of automatic steering devices. Two inertial measurement units were used to test the steering system performance by recording the rotation angle of front wheels and the steering wheel. The steering wheel had a steering clearance of 16.48° and an average wheel delay time of 0.14s. In the general range and small angle range, there is a small deviation between the actual corner and the theoretical corner. Responsibility and stability met requirements for agricultural machinery steering. Experimental results show that the test bench has stable performance in terms of status detection, steering control and measurement analysis, which could meet requirements for verifying working parameters of automatic steering devices. The research provides an efficient and reliable test bench for commissioning and performance testing of agricultural machinery automatic steering.

The article discusses the design of a modernized test bench for the study of cooling systems with intensification of inertial forces in the field. This bench will allow investigation the efficiency of heating the hydrocarbon coolant in the field of inertial forces and verification of the calculation results obtained in ANSYS environment

This paper presents the new transfer standard for torque measurements in the MN·m range and its metrological characterization through FEM analyses. Current methods used for torque measurements in such measuring range are not traceable to international standards; this situation has a deep impact in several industries, being especially important in wind energy generation. In order to improve the quality of torque measurements during wind turbine tests, the “EMPIR 14IND14-torque measurements in the MN·m range,”a new European funded project has been launched. This project aims to develop new transfer standards for obtaining accurate, reliable, and traceable torque measurements in the facilities used for testing wind turbine's performance. Within this project, CEM (Spanish Center of Metrology) has designed a new transfer standard for torque measurements named “force lever system.”Modeling and simulation technologies have been used not only for designing and testing the proposed system but also for enabling the estimation of its future associated uncertainty even before it is being manufactured. The results have proven that the expected metrological behavior of the designed system will ameliorate the accuracy of current measuring methods while ensuring torque measurements' traceability. The improvement of the torque measurements' reliability will make it possible to better diagnose its behavior and to improve wind energy generation efficiency.

This paper proposes a novel guidance magnet with 7 magnet poles for application in high speed maglev train. Its configuration and working principle are introduced in detail. Mathematical models of the guidance force and moment are established accurately by equivalent magnetic circuit method (EMCM), from which the relationships of guidance force - control current - guidance gap and moment - current change - angular deflection are derived. Finite element method (FEM) is also applied to analyze the performances and characteristics of the novel guidance magnet. The analysis results are in good agreement with those calculated by EMCM, which is helpful in designing, optimizing and controlling the guidance system. The comparisons are carried out between the novel and conventional guidance magnets. The contrast results indicate that the proposed novel guidance magnet possesses better performances compared to the conventional structure, especially the superior guidance capability and lower power loss. Finally, the relationship of guidance force-control current under the nominal guidance gap is validated by a test bench for magnet performance.

Bump foil journal bearings (BFJBs) are widely used in the superchargers of aviation piston engines (APEs). This paper proposes a method to evaluate the operating state of superchargers by monitoring the bearing temperature. A numerical model with a repeating symmetrical structure in the axial direction is established based on a certain type of supercharger, which solves the temperature field of BFJBs with the non-isothermal Reynolds equation and energy equation. It can be used to analyze the effect of thermal expansion on lift-off speed and stop-contact speed. A new test rig and six various BFJBs were designed to check the temperature characteristics of the BFJBs with variable load and speed. By comparing the numerical results with the experimental results, it was shown that the air film temperature increased almost linearly with the increase in bearing load and speed. However, the temperature increase caused by the rotation speed was significantly greater than the load. The structural parameters of the BFJB affected the bearing support stiffness, which had a nonlinear effect on the lift-off speed and air film temperature. Therefore, the proposed method to evaluate the state of superchargers with BFJBs was effective. These thermal characteristics can be used to guide BFJB design and predict the life cycle of BFJBs.

Several theoretical models for predicting the performance of tilting pad journal bearings (TPJB) have been developed by the scientific community over the years. However, reliable validation of the predictions based on the theoretical models, taking into account the complexity of TPJBs, demands robustness in the design and assembly of an improved test rig. Test bench designs for testing hydrodynamic bearings must carefully consider construction details as much as possible to observe the effect from the journal bearing and, consequently, improve the predictability of its dynamical behavior. In this context, there are still relatively few test rigs in the specific literature devoted to isolating the dynamic effects from hydrodynamic bearings for analysis purposes. Therefore, a novel test rig project is described in this work, also involving the design versatility characterized by measurement feasibility in rolling-element bearings and fixed-geometry, hydrodynamic journal bearings. This test rig aims to reproduce the most diverse operating conditions in order to measure the involved physical responses and validate the different models applied to the bearings. Therefore, the bearing performance can be properly evaluated, especially when operating under critical operating conditions, thus providing important contributions to the area of lubrication and rotor dynamics.

The E-LISA research project, under way within the Clean Sky 2 framework, has the objective of developing an innovative iron bird dedicated to executing tests on the landing gear of a small aircraft transport equipped with an electro-mechanical landing gear and electrical brake. Such tests include the simulation of complete landing procedures under different operating conditions such as runway friction, presence of periodical defects along the runway, variable aircraft weight, and approach speed. To this end, the iron bird requires novel solutions in both its architecture and its control scheme. This paper details an innovative solution that is being implemented in the E-LISA iron bird to enable the execution of tests on a landing gear, reproducing the effects of any type of runway irregularity. First, the rig architecture is presented in detail, with particular care toward the hybrid position/force control system that manages its operations. Then, a simulation model is introduced with the objective of verifying the control system stability and the test rig capability to reproduce on the test articles the effects produced on the landing gear leg of periodical runway irregularities. Simulations results are presented, highlighting the stability of the proposed control scheme and providing a preliminary assessment of the system performances.

Validation is important for a high product quality of drive components. An X-in-the-Loop test bench enables the integration of scaled prototypes through coupling systems and scaling models even before serial parts are available. In the context of X-in-the-loop investigations, it is still unclear whether a scaling model enables the early investigation of geometry variants in powertrain subsystems. In this paper, scaled geometry experiments taking into account the interacting system are considered to evaluate the scaling model in terms of early investigation of geometry variants. The aim of this paper is the functional investigation of geometrically scaled drive components by integrating scaled prototypes in an X-in-the-Loop test bench. Using an overload clutch with detents, component variants of different size levels are investigated in scaled experiments with a scaling model. The results confirm possibilities of X-in-the-Loop integration of scaled prototypes and their investigation on geometrically scaled drive components. The investigations show, therefore, the opportunities of integrating scaled drive components through the scaling model to support the investigation of geometry variants before serial parts are available. Scaled geometry investigations considering the interacting system can, thus, support product development.