Existing Test Bench Research Articles

Development of a test bench for biomechanical simulation-a preliminary study of mandibular forces.

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.

System of mutual loading of auxiliary electric machines with coverage of losses from mechanical power sources

Purpose. Increasing the level of safety and reducing the cost of rolling stock maintenance is an urgent problem for Ukrainian railways today. Existing test benches for auxiliary machines are usually built according to the scheme with direct loading of the tested electric machine and do not meet modern requirements for the quality and energy efficiency of testing. In this regard, there is a need to design energy-efficient test benches for testing auxiliary machines of electric rolling stock. Methodology. To achieve this goal, we used an analytical method of research to determine the optimal structure of the test bench. The paper considers the voltage balance diagram in the mutual load system. Separately, the calculations are presented, on the basis of which the design diagrams of the electrical and mechanical parts of the test bench are constructed, and the conditions for covering all losses in the mutual load system are determined using the design diagrams. Findings. In the course of the research, the power balance equation in the mutual load system was obtained. On the basis of the equations, a model of a mutual load system with coverage of all losses from a single source of mechanical power was built. The main advantage of the developed model is that it can be implemented both by numerical calculations using composite systems of equations and by object-oriented programming in specialized software systems. Originality. A rational scheme for testing auxiliary machines with the coverage of losses from a single source of mechanical power is proposed. The use of a single power source can significantly reduce the additional consumption of electrical energy due to the more efficient use of auxiliary equipment, in particular, a mechanical power source. Practical value. Based on the results obtained, it is possible to determine the parameters of the scheme for testing auxiliary machines at the design stage of the test bench. Implementation of the research results at auxiliary machine repair enterprises will reduce electricity consumption for post-repair testing due to the higher energy efficiency of the test scheme.

Method for analyzing in-situ volume change of large format lithium-ion hard case cells

To achieve high volumetric energy density in li-ion battery systems, it is relevant to predict the required space for reversible and irreversible volume change of the battery cells. In prismatic hard case cells, a locally inhomogeneous change in thickness occurs due to the rigid housing, which makes geometric analysis much more difficult. This publication highlights the challenges of analyzing prismatic hard case cells with existing test benches. In addition, an innovative test method is presented, in which the cells are both, compressed by air pressure and measured three-dimensionally. Influences such as gas inclusions between the electrode layers or plastic deformations of the housing can be reduced or even eliminated. This method enables a clear description of the local cell thickness at defined pressure, state of charge (SOC) and energy throughput (ETP). The resulting data can be used for a 3D simulation to estimate the required installation space within a battery system and the resulting force and pressure.

Engine-in-the-Loop in practical application: A sensitivity study toward the influence of test bench parameters

The complexity of automobile powertrains continues to increase, leading to increased development time and effort. One method to address this challenge is to shift vehicle calibration and testing tasks to simulations with Engine-in-the-Loop (EiL) test setups. This increases the efficiency of the development process through high flexibility, low prototype costs, an early starting point, and a high degree of automation. EiL emulates the dynamic interactions between the internal combustion engine and other powertrain components by closed-loop coupling to real-time simulation models. The coupling quality strongly depends on the interface properties, the hardware layout, and the control functionality of the dynamometer test bench. This paper analyzes an existing test bench and presents the impact of altered test bench parameters on different EiL quality aspects. Thereto, the setup is analyzed and a Simulink based grey box test bench model is derived. The latter is parametrized with a full factorial approach in comparison to real test bench measurements. The test bench model is then used for simulative investigations considering different test bench parameters: Two different use cases of Model-in-the-Loop (MiL) supported EiL are investigated. First, a simulative improvement of the test bench control quality by altering the PI based dyno speed controller parameters is investigated. The virtually calibrated controller parameters are applied to the real EiL system and compared to vehicle measurements. Second, sensitivity studies are shown with respect to dynamometer inertia and system dead time in terms of control quality and energy. As a major outcome, a compromise of control accuracy and stability for different speed controller parameters, dyno inertia, and system dead time is shown. Furthermore, it is demonstrated that EiL has only a small deviation in terms of energy compared to a full vehicle, making it a valid approach when considering CO2 emissions.

RESEARCH OF ROBOTIC SYSTEMS CONTROL METHODS USING MOTION RECOGNITION TOOLS, MACHINE LEARNING AND SKELETALIZATION ALGORITHMS

The aim of the research is to develop possible control methods of robotic systems based on the usability of motion detection equipment, skeletalization algorithms and robotic systems, integrating them into the existing test bench by performing compatibility tests. The article reviews the possible motion detection systems, establishing the criteria of applicability in the control of robotic systems, describes the experimental research plan, research stand, discusses the research results and presents summarized conclusions and suggestions for the integration of research results into the educational process.

Разработка подвижной части стенда с линейным двигателем и магнитным подвесом для моделирования инерционных нагрузок на объекте

We selected the main parameters for a new layout of a centrifugal installation featuring a linear motor and magnetic suspension. Since existing test benches for simulating linear accelerations have a range of disadvantages, we propose to consider an alternative to the classical layout, in particular, to reject the rotary link and replace it by a ring-like path structure with a linear motor, along which a trolley carrying the object under investigation will move on a magnetic suspension. We analysed various spatial stabilisation systems for the trolley moving at high velocities. We defined the key initial data, taking into account descent into planetary atmospheres, design specifics of products subjected to G-forces and existing centrifugal installations. We computed the parameters of a magnetic suspension based on high-temperature superconducting yttrium ceramics and electrical engineering parameters of the linear motor, and carried out strength calculations for the movable part of the test bench using the Femap with NX Nastran software package, accounting for the operational loads intended. The paper presents an option for implementing a new structural layout of an experimental installation that ensures linear acceleration testing in various operation modes

INVESTIGATION OF JET ENGINE INTAKE DISTORTIONS CAUSED BY CROSSWIND CONDITIONS

The Propulsion Test Facility of the TU Braunschweig is capable of investigating future jet engine intakes and fan aerodynamics to a high level of detail. A goal of this facility is the examination of coupled fan-intake-interactions which is not possible in any existing test bench around the world. Before doing research on these interactions, it is important to undergo proper studies of isolated aspirated intakes and fans under varying operating conditions (design and off-design). Therefore comparable result of the well-known LARA nacelle to existing experimental and numerical data has been generated for a first validation purpose. Therefore, comparable studies have been conducted with the LARA nacelle, to that of experimental and numerical investigations performed in the early 1990s at the ONERA F1 wind tunnel (mention reference), in order to generate results for validation. The first results of the validation experiment show differences in peak Mach number between the ONERA F1 and PTF experimental data for identical boundary conditions based on Mach number and crosswind. To investigate this further, a comprehensive numerical study has been carried out. It was inferred that the discrepancy was mainly caused by the Reynolds number effect within the PTF environment and its sensitivity to the inlet flow angle distribution with regard to angle of attack for crosswind. Within the validation test campaign, the experimental investigations showed a separation and reattachment hysteresis, which was identified when crosswind as well as nacelle mass flow had been increased or decreased to set up the different operating points. This phenomenon has still no established theoretical basis for understanding the aerodynamic behaviour. Overall, the applicability of conventional RANS models is shown. Additionally, the sensitivity to the aforementioned boundary conditions and the numerical reproducibility of the hysteresis phenomenon are discussed and compared to new experimental data in detail.

Development of brake system test-bed for high-speed train

As the speed of high-speed emu increases, the service conditions become more and more severe and complex. Brake system is an important guarantee of safety, so it is urgent to study the design concept and test method of brake system. There are relatively few researches on high-speed train brake test bench in China, and the existing test bench still has shortcomings in compatibility, real-time simulation and other aspects. Aiming at these problems, this work builds a brake test-bed for emu, which can complete the research test, performance test and reliability test of high-speed emu brake system and key components. At the same time, cooperate with Amesim, the braking process is simulated and predicted, and the braking process is analyzed by breakpoint, which provides a basis for the analysis, design and improvement of the braking system after experiment.

A Low-Cost Test Bench for Underwater Thruster Identification

Underwater vehicles are increasingly being used for the inspection of marine structures, bathymetry and underwater intervention applications. The manoeuvring performance of these vehicles is critically dependant on the quality of the thruster model which must faithfully represent the relationship between the thruster inputs and corresponding outputs. Thruster manufacturers typically provide only the essential electrical, mechanical and thrust performance characteristics, for this reason the identification of the thruster’s parameters is especially important for constructing a reliable control system for the underwater vehicle. Physical testing using some form of test bench is normally used for identifying the thruster parameters. These test benches usually consist of a water tank and the thruster which is clamped to some form of instrumented reaction frame for measuring the model parameters. The cost of a test bench varies according to two major factors which are the size and the instrumentation which strongly depends on the physical quantities that we are trying to measure. In this article we will make a state of the art survey of existing test benches in order to provide a technical basis that will allow us to build a low-cost test bench. A thruster will be modelled using the resulting test bench and the outcomes will be presented at the end of this paper.

CHOICE OF THE OPTIMAL PARAMETERS OF MEASURING THE SHAFT ROTATION FREQUENCY OF THE HYDRAULIC TRANSMISSION OF THE LOCOMOTIVE USING MICROCONTROLLER

Purpose. The article provides for finding solution to the problem of developing and improving the means for measuring tachometric data of the previously created information and measuring system for testing hydraulic locomotive transmission by substantiating the optimal sensor design and signal processing algorithms. At the same time first of all it is necessary to start from the possibility of modifying the already existing test bench for hydraulic locomotive transmissions at the Dnipropetrovsk diesel locomotive repair plant «Promteplovoz». Methodology. In the work, the researchers proposed a methodology for modifying the sensor design and the algorithm for processing its signals. It is grounded on previous developments of tachometric sensor of the optical type on the basis of D-2MMU-2 sensor of the microprocessor automated test bench system of hydraulic locomotive transmission in the locomotive repair plant conditions. Selection of the necessary measurement algorithm and the number of sensor teeth is substantiated by calculating instrumental and methodological errors. Also, the studies aimed at identifying the source of interference in the measurement of rotational speed are described and solution for its elimination has been found. Findings. For the designed rotation speed sensor of the optical type based on the existing D-2MMU-2 sensor, the authors analyzed the dependence of the methodological and instrumental errors. Based on the obtained data more rational variant of the rotation speed calculation algorithm is proposed, and the number of teeth of the sensor disk is justified. Further, the main source of measurement interference was established and a method for improving the hardware of the hydraulic locomotive test bench was proposed. Originality. There were conducted the studies according to the methodological and instrumental errors of the designed rotation speed of sensor. The mechanisms of interference filtering arising from the sensor rotation speed fixing were proposed. Additional studies have shown the need for a hardware revision of signal conditioner scheme. Practical value. Conducted studies make it possible to establish a rational number of sensor disk teeth, which allows improving the measurement algorithm. It was also performed a hardware improvement of signal conditioner scheme from the sensor, helping to get rid of interferences. The results of measurements in studies are the initial data to perform further studies in order to determine the technical condition of hydraulic transmission UGP 750-1200 during factory testing after repair.

Effect of flow configuration on Darcian and Forchheimer permeabilities determination in a porous composite tube

Using Fuel Cell on board of aircraft imposes to extract light species (such as Hydrogen and light hydrocarbons) from the liquid fuel which is stored and used, possibly at temperatures where a fuel pyrolysis occurs. Natural porosity of composite material could be used to filtrate the selected species. Hence the permeability of the porous media becomes one of the key parameter to be accurately measured. It is often determined experimentally in laboratory with disc samples (outlet of the flow is achieved through the porous material) and normal flow. However, this configuration is far from the realistic one consisting of tubes (a main flow is found additionally to the one through the material, tangential permeability). Therefore, the effect of a second outlet on the Darcy's and Forchheimer's permeabilities characterization should be studied (despite the permeability is an intrinsic property of the material itself and it should not be dependent on the test apparatus). This paper focuses on a new way of using an existing test bench for the determination of Darcy's and Forchheimer's permeabilities of C/SiC porous composite tube by taking two outlets into account. Operating parameters (temperature, pressure and mass flow rate) are measured for three different configurations: i) primary outlet (P.O) is 0% open ii) P.O is 50% open and iii) P.O is 100% open. Then Darcy's and Forchheimer's permeabilities are computed by ISO and P2 methods using a direct search algorithm. Obtained results from different methods are compared and discussed. They are in agreement with the literature data which guarantees the reliability of the test bench and of related measures.

The Impact of the Aerogun Recoil Test Bench Stiffness on the Test Precision

The recoil of airborne machine gun affects the safety of aircrafts. In order to improve the test precision of the aerogun recoil and evaluate the performance and airborne security air guns more reliable, a certain type of recoil test bench of airborne launcher was selected as the research object, and use the analytical software—ANSYS to build the finite element model which is under impact load of the recoil test scaffolding. It is concluded that increasing the stiffness of the recoil test bench is conductive to improve the measurement precision of recoil by analyzing the influence of different stiffness of the test bench on the recoil response. In this paper, an improved design method was proposed to raise the stiffness of test as the natural frequency of existing test bench is low. The modal analysis show that the first natural frequency of modified test bench increases from 10.89 HZ to 100.57 HZ, beneficial to improving the test accuracy of recoil.

Complementary tribometers for the analysis of contact phenomena in grinding

The characterization of friction and tribological phenomena occurring in grinding requires reliable experimental input data. Up to now, existing test benches exhibit important limitations. Steep thermal gradients and elastic deformations of both machine structure, and rubbing elements are the main sources of inaccuracy cited in the literature. In this paper, an alternative approach is presented for the study and characterization of contact phenomena in grinding. It consists of two complementary test benches: the On-Machine Test Bench and the High Speed Tribometer. They are designed to overcome the limitations of current grinding experimental studies.On the one hand, the On-Machine Test Bench enables accurate control of process parameters. This allows assessing the effect of the different grinding mechanisms on process forces, and specific energy. In addition, its configuration avoids steep thermal gradients; consequently, it is possible to obtain stable and accurate temperature measurements that can be directly related to process variables. On the other hand, the High Speed Tribometer enables to isolate adhesive effect because of its predominance. This test bench allows an accurate control of contact pressure and contact area. Then, adhesive phenomena can be characterized and related to process parameters using force and temperature measurements.Experimental results obtained in both test benches are presented. A wide range of data (forces, specific energy, temperatures, wear…) concerning contact conditions in grinding can be obtained from this complementary approach.

Hybrid acoustic synthesis – Assessment of rear final drives in an early stage of development, on the basis of transfer path analyses and test bench measurements

In order to be able to assess the acoustic characteristics of new rear axles respectively rear final drives at an early stage of development, a hybrid evaluation procedure was developed: this makes it possible to compare various construction stages on the basis of vehicle and test bench measurements. Transfer path analyses are used to calculate what contribution of the sound pressure on the driver’s ear is made up of structure-borne sound from the rear final drive (based on operational acceleration measured on the test bench and the bodywork’s transmission characteristics measured on the vehicle), which is used to classify the various construction stages. To use the test bench measurements for forecasting, the test object must have vibration characteristics that are as close as possible to those of the vehicle. In view of the above, comprehensive comparative measurements were taken with the help of artificial excitation and operational excitation. The measurement positions identified in the process were used to validate the calculation method by operating the very same rear final drive on the test bench and in a vehicle. In both cases, the rear final drive’s contribution of the total vehicle interior noise level was calculated, in one case on the basis of excitation from the vehicle measurement and in the other case on the basis of excitation from the test bench measurement. The good correlation between the vehicle-based and test bench-based calculations confirmed the applicability of the method. The “virtual” installation of the rear final drive enables faster construction stage comparisons because there is no need for alteration work on the vehicle and the rear final drive that is to be compared can simply be integrated into the existing test bench environment.

Virtual Electric Vehicle Design using Real-world Coupled Realtime Simulation

Electric Vehicles gain more and more importance in public media as well as in scientific research. At the Department of Energy Conversion Technology a collegiate student project has been established to construct an electric vehicle based on a buggy chassis. Simulation models of the vehicle have been realized to study the system. A test bench for the propulsion system has been built. To use the test bench for hardware-in-the-loop tests of the communication system the ECUs are coupled with the existing test bench. The obtained results will be fed back to the upcoming new vehicle planned for the near future.

Status of the ion sources developments for the Spiral2 project at GANIL

The SPIRAL 2 facility is now under construction and will deliver either stable or radioactive ion beams. First tests of nickel beam production have been performed at GANIL with a new version of the large capacity oven, and a calcium beam has been produced on the heavy ion low energy beam transport line of SPIRAL 2, installed at LPSC Grenoble. For the production of radioactive beams, several target∕ion-source systems (TISSs) are under development at GANIL as the 2.45 GHz electron cyclotron resonance ion source, the surface ionization source, and the oven prototype for heating the uranium carbide target up to 2000 °C. The existing test bench has been upgraded for these developments and a new one, dedicated for the validation of the TISS before mounting in the production module, is under design. Results and current status of these activities are presented.

The Study of Drive Characteristic and Experimental Approach about Planetary Gearing Mechanism

The transmission indexes which include transmission error and backlash are analyzed, it points out the reasons for the formation of these indexes. The experimental principle and approach about transmission accuracy and stiffness are introduced based on the existing test bench of our university.

Integration of FlexRay-based control units in existing test benches

Today, measuring and control technology in vehicle test benches is connected to the control units via CAN interfaces. With the increasing use of FlexRay, however, FlexRay based control units need to be integrated in test benches as well. This paper presents a universal concept which BMW Group has developed and implemented using the Ixxat hardware and software platform. The concept safeguards investment in many test benches by enabling existing technology for FlexRay testing.

Further development of the final functional test for gasoline engines

Manufacturers of internal combustion engines are making increasing use of the final functional test in modern large-series production. This test permits accurate and comprehensive fault detection, thus assuring more reliable test results and lower testing costs. Existing testing facilities must be improved continuously in order to be able to meet ever more exacting demands on the quality of test results and to keep costs down. Under a joint project, the Department of Internal Combustion Engines and Automotive Engineering of Vienna University of Technology and Opel Austria Powertrain have succeeded in further developing the two existing test benches for the final testing of gasoline engines at Opel’s production plant in Vienna- Aspern.