Method for adjusting a test bench device

Abstract

In order to provide an improved method for adjusting a test bench apparatus 4, in which a rotating test object 1 is connected to a rotating load machine 2 via a mechanical connecting shaft 3 and at least one angular velocity prevailing in the test bench apparatus 4 is measured, the rotational behavior of the test bench apparatus 4, i.e. at least the measured angular velocity and the angular velocity ω of the test object prevailing in the test object 1, are measured. P The dynamic behavior of the test object 1 is modeled by a first differential equation system. Based on this, the rotational torque T P is modeled by a second differential equation system, and the angular velocity ω of the test object is calculated based on the first and second differential equation systems. P and the rotational torque T of the test piece P A state observer is generated to estimate the angular velocity of the test object, ω^, based on the state observer. P and the estimated rotational torque T^ of the test piece P is calculated and the calculated estimate is used to adjust at least one adjustment angular velocity prevailing in the test bench device 4 and / or at least one adjustment rotational torque prevailing in the test bench device 4.

Description

[Technical field]

[0001] The invention relates to a method for adjusting a test bench arrangement, in which a rotating test object is connected to a rotating load via a mechanical connecting shaft and at least one angular velocity prevailing at the test bench arrangement is measured, in which the rotational behavior of the test bench arrangement, i.e. the dynamic behavior of at least the measured angular velocity and the angular velocity of the test object prevailing at the test object, is modelled by a system of first differential equations. [Background technology]

[0002] For a long time, test benches have become an essential tool in many different technical fields of application. This situation is especially true for the automotive industry, where trends such as the electrification of the powertrain continually provoke new test technology challenges in an ever-shortening innovation cycle. In this context, lower costs, higher adaptability, shorter setup times and higher dynamics are among the main factors that are highlighted in many of these new test technology challenges.

[0003] The abovementioned factors may be interrelated. Firstly, costs can be reduced, in particular by reducing the hardware used in the test bench. In this context, in particular measurement-technical and sensor-based devices can be mentioned, which in many cases can be regarded as expensive components on the one hand and can significantly increase the implementation, operation and maintenance costs of the test bench on the other hand. Furthermore, in many situations of use, a reduction in the number of sensors can significantly increase the adaptability of the test bench. In this context, an advantage is the cabling costs, which generally fall with the reduction in sensors. Said cabling costs can be beneficial in particular when converting and / or adapting the hardware of the test bench. For the same reason, a smaller number of sensors allows for a reduction in the setup times, which often occur when replacing a test bench.

[0004] In contrast, the fourth factor, which requires higher dynamics, often has other consequences with regard to the number of sensors to be provided. In this case, "dynamics" means changes in non-steady-state operating conditions, i.e. changes in certain variables of the test bench device, such as rotational speed or torque, within short time intervals, for example in the millisecond or microsecond range. Large changes in such variables can also occur here. It is often very important for the highly dynamic operation of a test bench to be informed as precisely as possible about the test bench situation, in order to ultimately also allow highly dynamic adjustment of the test bench device. In this connection, the respective additional measurement variables may be useful or may still be necessary. This trade-off with regard to the number of sensors to be provided occurs in various test technology applications.

[0005] Thus, in the case of a powertrain test bench, the powertrain to be tested is arranged on the test bench as a test object and is generally connected to at least one load machine (dynamometer) via several mechanical connecting shafts. In this case, the drive unit of the powertrain, for example an internal combustion engine and / or an electric motor, is operated on the test bench against the at least one load machine in order to test the various load situations that are expected during real operation. Such a powertrain test bench with several load machines is known, for example, from DE 10 2008 041 883 A1. In this case, it is often useful to know the response precisely via the rotational torques generated by these load machines, in particular in order to avoid mutual influences between these load machines.

[0006] In contrast, in the case of engine test benches, generally only one individual drive unit, for example an internal combustion engine and / or an electric motor, is provided as the test subject and is connected to a load machine (dynamometer) by means of a connecting shaft. An example to be highlighted in this context for operating modes in which additional measurement information can be of great importance is the so-called damping control, which is known, for example, from AU-A-519092. In this case, the general task is to determine the damping component of the control signal used to control the test bench from the actual rotational speed of the test bench, also referred to below as "rotational speed of the test subject", and / or the rotational torque of the test subject generated by the test subject. In this case, the measurement variables of the rotational speed of the test subject and / or the measurement variables of the rotational torque of the test subject significantly simplify the control concept.

[0007] If expensive and sophisticated sensors are to be eliminated for reasons of cost and efficiency, a clear improvement in the operating behavior of the test bench is possible, but it often happens that it is completely impossible to measure certain measurement variables with sufficient accuracy, such as, for example, the rotation angle of the test object, the rotation speed of this test object, or the torque of the test object generated by this test object. The sensors required for this purpose are not available, or the high costs caused by the installation and use of known sensors themselves make their use impossible. Furthermore, in many cases, test objects must also be tested for which it is basically not possible to obtain the measured value of the variable to be considered or which are not provided with suitable measuring parts. An example in this regard is the internal torque generated by an internal combustion engine or an electric motor, and therefore not the torque actually outputted at the output shaft, but the torque actually generated. This internal torque cannot often be measured directly.

[0008] For the above reasons, the prior art has devised a number of methods in which sensors not present in the real test bench environment are replaced by so-called virtual sensors. For this purpose, typically, desired but not directly available measurement variables are mathematically estimated from present measurement variables, often using observer techniques well known from control technology. The measurement signals generated in this way are often called virtual measurement signals.

[0009] In this connection, non-patent document 1 discloses the use of various state observers in a test bench for an internal combustion engine. In this case, based on the state observers provided, an estimate for the internal rotation torque generated by the internal combustion engine, an estimate for the rotation speed of the internal combustion engine, an estimate for the rotation speed of the load machine and an estimate for the difference angle between the internal combustion engine and the load machine are calculated. In this case, however, the above-mentioned rotation speeds are also detected by measurement technology, which fundamentally impairs these estimates.

[0010] AU 519092 A1 discloses a method for damping control in a test bench for an internal combustion engine, where an estimate of the torque of an internal test object is calculated based on the measured shaft torque and the measured speed of the test object, but no details are given on the model used for the estimate and the state observer derived from the model, which makes it significantly more difficult to apply the proposed concept to other test bench arrangements, such as a test bench for an electric motor.

[0011] AU 522354 A1 discloses an estimation of the shaft torque acting on the connecting shaft of a motor test bench. On the basis of this estimation, a further estimate of the rotational torque of a test object, which prevails in a test object consisting of at least two rotational measurements, is calculated. Here again, the specific configuration of the used estimator is not specified.

[0012] In contrast, DE 10 2020104 314 A1 discloses a model predictive control of a test bench for testing drive components, where in particular future values ​​are estimated by variables occurring in the test bench device, such as the speed of the connecting shaft and the torque generated by the load and the test object. Since this publication focuses on the control of the state variables of the connecting shaft, a concrete model of the test bench device is disclosed, but the torque of the test object is modeled in a very conventional manner.

[0013] The cited prior art has several features in common. The first feature is that none of these publications discloses a simultaneous estimation of the rotational speed of the test object and the rotational torque of the test object generated by the test object, but rather that at least one of both variables is measured. However, in many cases, precise information on the rotational speed of the test object and the rotational torque of the test object is a prerequisite for monitoring the power converted in the test object. This can be very important, especially in the case of electric motors rotating at high speeds. In the case of electric motors rotating at high speeds, the problem often arises that the test bench control does not have access to the rotational speed of the test object and the rotational torque of the test object, but the power converted by this object must be taken into account during the operation of the test bench, especially in order to avoid thermal overload of the mostly valuable test object ("golden sample").

[0014] Another feature of the cited prior art is that the publication does not disclose an estimation of the rotational speed of the test object, in which the estimated rotational speed of the test object is additionally provided as a measurement variable. For safety reasons alone, particularly in the case of test benches for electric motors, very high rotational speeds of the test object must often be monitored. However, in the case of flaws in the measurement technology, this can only be achieved by reliable estimates.

[0015] Furthermore, none of the above publications discloses how the internal torque of a test object generated by the test object can be usefully modeled for subsequent estimation, particularly in the case of electric motor test benches. Moreover, it is very unclear how the models of the torque of a test object known from the prior art can be usefully extended, for example with the aim of improving the accuracy of the model. Moreover, in many cases, possible extension methods at the same time significantly increase the complexity of the model, which can be a drawback, particularly in practical applications.

[0016] For the reasons stated above, when using implementations of the cited concepts, partly serious problems arise, as a possible consequence of which the test bench and / or the object under test can be damaged due to imperfect operating properties of the test bench. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] DE 102008041883 [Patent Document 2] AU Patent Application Publication No. 519092 [Patent Document 3] AU Published Patent Application No. 522354 [Patent Document 4] DE 102020104314 A1 [Non-patent literature]

[0018] [Non-Patent Document 1] "Nonlinear Observers for Closed-Loop Control of a Combustion Engine Test Bench" G. Reale et al., American Control Conference (2009) 4648-4653 Summary of the Invention [Problem to be solved by the invention]

[0019] The object of the present invention is therefore to provide an improved method for simultaneously estimating the rotational speed of a test object and the rotational torque of the test object, which can be used flexibly, in particular on test benches for motor vehicles, in particular on test benches for electric motors. [Means for solving the problem]

[0020] According to the invention, this problem is solved by the features of the independent claims, in which a test bench arrangement is provided in which a rotating test object is coupled to a rotating load machine, preferably as an electric motor, via a mechanical coupling shaft, and in which at least one prevailing speed, but preferably the speed of the load, which is detected from the load machine, is measured.

[0021] In this case, in a first step of the method of the invention, the overall rotational behavior of the test bench device is modeled. In this case, the dynamic behavior of test bench variables, such as the load speed, the speed of the test object, the shaft torque, the torque of the test object, which are generally related to the rotational behavior of the test bench device, is shown by way of example, but at least the dynamic behavior of the measured speed and the speed of the test object obtained from the test bench is shown. For this purpose, a first system of differential equations is shown. This system of first differential equations is in particular configured as a rotating multi-mass system, which therefore has at least two rotating or inertial bodies which are connected to each other via elastic and damping elements. In this case, the at least two rotating or inertial bodies are used to represent the test object and the load machine, while the at least one elastic and damping element represents a mechanical connecting shaft between these rotating or inertial bodies. In this case, it is important for the method of the present invention that the load torque generated by the load machine and the test object torque generated by the test object are input variables of the first differential equation system. In this case, the load torque acts on the inertia representing the load machine, whereas the test object torque acts on the inertia representing the test object.

[0022] The next method step represents the core of the invention. In this case, a model of the torque of the test object is generated based on a system of second differential equations of an autonomous system, which may have a high model order. In this case, a direct current component is represented based on a first subsystem, and m further vibration subsystems are used to generate m harmonic components of the torque of the test object. In this case, the m vibration subsystems for modeling the m harmonic components are preferably configured as damped and / or undamped oscillators. In the regulation technology, such systems for representing input variables are already known as so-called "exosystems", and although their use can bring about a series of unexpected positive effects, they have not found application in test bench technology so far.

[0023] According to the invention, the first and second systems of differential equations are combined into an integrated model, which is generated in a further method step for estimating the rotational speed of the test subject and the rotational torque of the test subject, where the measured rotational speed is the input and the rotational torque of the test subject to be estimated and the rotational torque of the test subject to be estimated are the outputs of a state observer. Then, based on the generated state observer, an estimate for the rotational speed of the test subject and an estimate for the rotational torque of the test subject are calculated. These estimates are used in a further method step for adjusting at least one rotational variable prevailing in the test bench.

[0024] In this case, a first positive effect of the use of an autonomous exosystem for modeling the rotational torque of the test object is obtained in particular by the circumstance that the rotational torque of the test object occurring as an unknown input in the first system of differential equations can be replaced by the provided exosystem. The model thus generated can be understood as a new integrated model consisting of the rotational dynamics of the test bench device and the dynamics of the rotational torque of the test object. Due to the autonomous character of the exosystem, the dependency of unknown external variables present in the first system of differential equations is thus eliminated. This effect often improves the quality of the calculated estimation, since unknown external input variables can be a major obstacle in many applications of observer technology. Furthermore, if the estimation of the rotational speed of the test object is performed by reconstructing the state of the integrated model based on said estimation, as is a common practice in observer technology well known from regulation technology, the rotational torque of the test object is estimated without additional efforts in the concrete situation. Thus, the observation of the power transformed in the test object described above is performed almost automatically.

[0025] A second advantage, which is valuable for the practice, is obtained from the construction of the second system of differential equations in the method of the invention or from the construction of an exosystem for modeling the rotational torque of the test object. If it is considered that the accuracy of the reconstruction of the signal can be optionally improved by adopting harmonic components, this immediately starts the method for extending the provided exosystem or the second system of differential equations. If additional vibration subsystems are added accordingly as oscillators for taking into account other harmonic components, the number of state variables in the exosystem and the resulting integrated model increases. However, since the respective vibration subsystems do not influence each other but cancel each other out, this does not make the exosystem and the resulting integrated model significantly more complicated or more difficult to handle. This aspect is important when evaluating the practical applicability of the method of the invention, since in practice one generally tries to avoid models with high orders. However, since the above-mentioned subsystems do not influence each other at all, the great advantage, especially of the improved model accuracy, outweighs the only negative consequence of the addition of other vibration subsystems, namely the need to have to take into account additional state variables. Naturally, this property also applies to exosystems that have a high model order to begin with.

[0026] In another preferred aspect of the method of the invention, the stability of the exosystem used and the resulting integrated system can be ensured. The vibration subsystems for modeling the harmonic components are damped and / or undamped oscillators, whose eigenvalues ​​lie on the imaginary axis or in the left half of the complex plane, so that the stability properties of the resulting integrated system cannot be fundamentally changed by adding other oscillators. As regards the stability of the models used for the estimation, even when the model parameters change, there is no risk of a possible loss of stability, so that the exosystem for modeling the rotational torque of the test object can be adapted to the changing rotational variables of the test bench during its operation or can be followed by said changing rotational variables, preferably a measured rotational speed, such as a load speed obtained from a load machine.

[0027] In this respect, it should be noted that although the object of the present invention is essentially within the scope of engine test benches, and in particular within the scope of electric motor test benches, the method of the present invention can also be used on many other test benches, for example powertrain test benches, roller test benches or component test benches. Furthermore, the specific adjustment tasks that are solved using the estimated torque of the test object and the estimated speed of the test object according to the method of the present invention can be broadly interpreted. Besides the damping adjustment already mentioned, further applications in this respect can be listed, in particular, the simulation of rotating or inertial bodies and n-alpha operation.

[0028] The present invention will now be described in detail with reference to Figures 1 to 6, which show exemplary, schematic, non-limiting preferred configurations of the present invention. [Brief description of the drawings]

[0029] [Figure 1] FIG. 2 is a schematic diagram of a test bench apparatus. [Diagram 2]FIG. 1 is a schematic diagram of a model of a dual-mass oscillator (Zweimassenschwinger). [Diagram 3] 4 shows an exemplary progression of the rotational torque of a test specimen. [Figure 4] FIG. 13 is a block diagram of an exemplary control configuration when the rotation speed of the test object and the rotation torque of the test object are not estimated in accordance with the present invention. [Diagram 5] FIG. 2 is a block diagram of an exemplary control configuration for estimating the rotation speed of a test object and the rotation torque of the test object according to the present invention. [Figure 6] A test bench setup with two load machines is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] FIG. 1 shows the main components of an engine test bench diagrammatically. In this case, a rotating test object 1 is coupled to a load machine 2, preferably as an electric motor or internal combustion engine, which applies a load torque to the test object 1 via a connecting shaft 3. In general, the load machine is configured as an electric machine. The unit consisting of the test object 1, the load machine 2 and the connecting shaft 3 is also referred to in the context of this document as a test bench apparatus 4. In the illustrated situation, an automation system 5 calculates the control variables for the drives of the test bench apparatus 4, in particular for the individual active elements, and pre-sets said control variables in the test bench apparatus 4. This is particularly the case when the load machine 2 is rotated by a load torque T D The rotation torque T of the load machine is included in the preset. DIn addition to the control variable for , the automation system 5 can also output a control variable α for the test object 1. In this case, depending on the test object 1, the control variable α can have different meanings, for example in the case of an internal combustion engine it can indicate the pedal position or the throttle valve position, while in the case of an electric motor its meaning is often specified as a percentage of the maximum rotational torque that the test object 1 can generate. It should be noted that in this case the test object in question does not necessarily have to be connected to the automation system 5. In such a case, the presetting of the control variable α must no longer be performed by the automation system 5, but in another way, for example by presetting of an operator of the test bench or by a control device provided in the test object 1.

[0031] As a result, the control variable is converted by the adjusting device 6 of the load machine 2 or the adjusting device 6′ of the test object 1 into a corresponding adjusting variable, which is adjusted by the adjusting variable. If the load machine 2 is configured as an electric machine, for example a synchronous machine or an asynchronous machine, the rotational torque T D is the air gap torque T L In this case, the air gap torque T L The winding current or the winding voltage of the load machine 2 can be used as a regulating variable for generating the air gap torque T L is generated by the load machine 2 in a known manner and sensed at the rotor of the load machine 2.

[0032] The actual value of the regulating variable, such as the actual value of the angular velocity of the load machine 2 shown in FIG. 1, is detected by a suitable sensor and transmitted to the automation system 5 via a suitable signal line. To this end, the said angular velocity is the “load angular velocity” ω D The angular velocity of the load is also called ω D can be detected, for example, by a rotary encoder 7. In the method of the present invention, the angular velocity ω P is not used as a measurement variable, and the shaft torque T STIn most cases, the angular velocity ω and the rotation speed n of the test bench device 4 are not used as measurement variables. This is indicated by the dashed signal line Y. In this case, the angular velocity ω of the test bench device 4, e.g. the angular velocity ω of the test object P and the number of revolutions of the test object n P are correlated by the well-known formula ω=πn / 30. The effect of both on the method of the present invention can be considered to be equivalent. For consistency in the following description and mathematical description of the above model, angular velocity is used below primarily and without limiting the general concept.

[0033] In a first step of the method of the invention, a first system of differential equations is generated in order to model the rotational behavior (hereinafter also referred to as the swing behavior) of the test bench arrangement 4. For this purpose, preferably a rotating multi-mass system is generated. The simplest configuration of this system is given by a dual-mass swing element. Such a dual-mass swing element is shown in FIG. 2. The shaft torque T ST , the air gap torque T generated by the load machine 2 L , the rotational torque T of the test piece P , the angular velocity ω of the load machine D and the angular velocity ω of the test object P In addition, FIG. 2 shows the stiffness c and damping d of the mechanical connecting shaft 3 between the test object 1 and the load machine 2, as well as the inertia torque J of the test object. P and the inertia torque of the load machine J D These parameters can be considered as known. Based on the dual mass oscillator shown in FIG. 2, a well-known system of first differential equations for describing the rotational behavior of the test bench device 4 is given by:

[0034]

number

[0035] Where:

[0036]

number

[0037]

number

[0038] Like any model of a real physical system, the specific system of first differential equations represents a simplified model abstraction of the real behavior of the modeled test bench device 4. Thus, when formulating the model, the inertial torque of the elastic connecting shaft is expressed as the inertial torque J D and inertia torque J P It is assumed that all elements of the equation are linear. Therefore, possible non-linear characteristics of the test bench device 4, such as shaft play, non-linear stiffness or static friction, are not taken into account. D from the air gap torque T L The dynamic characteristics of the actuator given by the load machine 2, which generally occurs due to a combination of dead time and PT1, are also ignored when converting to the load machine 2. When the dynamic characteristics of the actuator are ignored, the air gap torque T L is the control variable T DBy taking into account the ignored concrete characteristics, further, more complex models of the test bench device 4 can be directly shown. However, the shown system of first differential equations is sufficient to explain the method of the invention. These model parameters are considered as known for the further consideration. Based on the described model, a formulation of the problem according to the invention can be considered with respect to the shown embodiment and for a better understanding, namely the variable ω P and T P Specific consideration will be given to identifying methods for estimating

[0039] To solve this problem, as explained, a second differential equation system is developed to calculate the rotational torque T P The torque T generated by the test piece is shown. P is modeled by a second differential equation system. In this case, the rotational torque T of the test object is calculated based on the first subsystem of the second differential equation system. P The DC component of the second differential equation system is shown, and the rotational torque T of the test object is calculated based on m separate vibration subsystems of the second differential equation system. P The m harmonic components of are modeled as damped and / or undamped oscillators.

[0040] In a specific embodiment, three (m=3) harmonic components are considered. This results in a second differential equation system of the form

[0041]

number

[0042] Where:

[0043]

number

[0044]

number

[0045]

number

[0046] The remaining state variables z k,1 ,z k,2 must always be considered as a pair of k oscillatory subsystems, each of which can be classified into a k-th order oscillatory subsystem. In this case, the loop variable k is used to index the oscillatory subsystems and the associated variables. In particular, an oscillatory subsystem can be understood as a part of a system of differential equations, each of which consists of interacting state variables of a state vector. Thus, for each of these oscillatory subsystems, for example, we have the vector-valued differential equation

[0047]

number

[0048]

number

[0049] Starting from an initial state other than zero, both variables z κ,1 and z κ,2 respectively execute sinusoidal transitions which are phase shifted by 90° with respect to each other. When one of these two state variables is selected, the result is the rotational torque T P The individual harmonics of the torque can be shown, and by adding up the harmonics thus identified, the rotational torque T of the test object including all the harmonics can be calculated. P can be shown.

[0050] Output variable T P The state variable z0 is added to exactly one corresponding state variable of each of the multiple oscillatory subsystems to generate the output vector c S In this regard, FIG. 3 shows the rotational torque T of the test piece thus generated. P The possible transitions of

[0051] angular frequency ζ k To parameterize, for example, the angular frequency ζ k As a result, the relation

[0052]

number

[0053]

number

[0054] It should be noted that the angular frequency ζ k The selection of can be performed in a completely different way, for example the angular frequency ζ k and the angular velocity of the load ω D However, this can be achieved by using an odd ratio between the angular frequency ζ k may be selected solely for the application by one skilled in the art.

[0055] The development of the second system of differential equations to improve the accuracy of the model can be carried out by adding more harmonics exclusively. This allows the number m to be increased. It should also be noted that consecutive harmonics do not necessarily have to be used. For example, only odd harmonics or only even harmonics may be used, or any arbitrarily selected harmonics may be used.

[0056] ω P and T P To actually compute an estimate for , the first and second systems of differential equations are combined into one combined system. To represent this step more precisely, first, based on the shorthand notation for the system parameters above, the first system of differential equations is expressed as

[0057]

number

[0058]

number

[0059]

number

[0060]

number

[0061] In a preferred method, however, the well-known Luenberger observer may be used. However, this observer need not be selected exclusively. As is known, the Luenberger observer includes a copy of the system of differential equations describing the dynamics of the variables to be estimated, and correction terms. As a result, in particular, the differential equations of the observer

[0062]

number

[0063]

number

[0064]

number

[0065]

number

[0066] The quoted observer differential equation can be further transformed into the vector-valued output equation

[0067]

number

[0068] A notable advantage of the present invention in this regard is that, for example, the shaft torque T ST The estimate for T^ ST The advantage of this is that the output equation of the state observer can be easily extended to further calculate the estimate T̂. In the preferred embodiment of the present invention, the output equation of the state observer is expanded by adding one line. ST To calculate , the known parameters of the shaft stiffness c and the shaft damping d are used.

[0069]

number

[0070] Similarly, for example, the angular velocity of the load ω^ D A further output variable for the estimate of the air gap torque T can be generated. In this case, it may be useful to combine already existing output variables into a new output variable. Then, from the differential equation of the observer in the described embodiment, L and the angular velocity of the load ω D It is clear that the air gap torque T L and the angular velocity of the load ω D can be replaced by other angular velocities or rotational torques prevailing in the test bench device 4 when implementing the invention, e.g. the shaft torque T ST and the angular velocity of the connecting shaft 3. In such a situation, the basic method does not change at all, and only the first differential equation system needs to be appropriately adapted. By adapting this first differential equation system, the control variable T D is the air gap torque T L Therefore, in general, the control variable T D and air gap torque T L The relationship between is modeled by a combination of dead time and PT1, where the dead time can preferably be represented based on the Padé approximation.

[0071] As mentioned above, the angular frequency ζ κ is the angular velocity of the load, ω D or as a function of the dominant rotational variables in the test bench device 4, and the correction gain K is set, as is often the case conventionally, as a function of the usual parameters of the dynamic matrix A^, the resulting state observer also has a function of the angular frequency ζ κ Depends on the angular velocity of the load, ω Dor directly depending on other rotating test bench variables. In such a situation, the state observer may be D or automatically adapted to possibly changing other rotational variables of the test bench device 4. This can in part significantly improve the operating behavior of the test bench device 4.

[0072] Below, we explain how to estimate ω^ P and T^ P can be used for adjusting a test bench arrangement 4 on the basis of figures 4 and 5. In this case, figure 4 shows a block diagram of a regulating circuit which is used in this way, in particular for so-called highly dynamic shaft torque regulation in test bench arrangements for electric motors. This regulating circuit is implemented, for example, in the automation system 5, in particular as software in the microprocessor-based hardware of the automation system 5. However, other implementations, for example in the form of integrated circuits (for example FPGA, ASIC, etc.), are also conceivable.

[0073] In general, the purpose of such highly dynamic shaft torque adjustment is to adjust the shaft torque T ST The target shaft torque T * ST The aim of the present invention is to make the rotational torque T of the test object follow a preset time course. In this case, such a target shaft torque may have a highly dynamic component and may essentially change within a few milliseconds. In this case, the rotational torque to be adjusted and the angular velocity to be adjusted are often called "adjusted rotational torque" and "adjusted angular velocity". In order to solve the above-mentioned adjustment problem, the rotational torque T P And the actual target shaft torque T * ST From the target angular velocity ω * is calculated. In the implementation shown in FIG. 4, this is performed in a large-scale simulation MS of the block diagram. Then, this target angular velocity ω * is adjusted by the regulator ωR, and the shaft torque T STis a preset target value T * ST The rotational torque T of the test piece is selected as P is not generally known for the above reasons, so the rotational torque T P In order to calculate the torque, a Kalman filter KF is often used. In particular, the measured shaft torque T ST acts as an input to this Kalman filter KF. Thus, the conventional implementation of this highly dynamic shaft torque regulation shown in FIG. 4 is D , angular velocity ω of the test object P and shaft torque T ST are determined by measurement technology in the test bench and are provided for adjusting this test bench.

[0074] However, for the reasons mentioned above, in the case of electric motor test benches, the angular velocity ω D and shaft torque T ST is not measured. Therefore, this method is not possible in many cases. Furthermore, for safety reasons, the power converted in the test object 1 must be monitored in many cases. For this reason, the rotational torque T P must also be known. Furthermore, if a rotary encoder is present on the electric motor, it often provides the desired measurement signal exclusively at very low scanning rates, for example 100 Hz. Since modern test specimen conditioning devices R are generally run at scanning rates of at least 5 kHz, this situation in itself significantly impairs the dynamics of the test bench conditioning device R used.

[0075] The concept of shaft torque adjustment is that the angular velocity ω P The existing tuning concept is extended by the state observer of the present invention so that it can be used without measuring the angular velocity ω of the test object. Thus, the block diagram shown in FIG. 5 can be constructed. P and shaft torque TST The use of highly dynamic shaft torque regulation is also possible in situations where is not provided as a measured variable. In this case, the rotational torque T P A further advantage of the method of the invention is obtained that the Kalman filter KF for initially estimating can be omitted.

[0076] In addition to the examples of use described on the basis of figures 4 and 5, the method according to the invention can be used to solve numerous other test engineering control problems, such as mass simulation, subtractive control, etc. In addition to these control engineering problems, other fields of use can in particular be mentioned, such as other forms of test benches. In this case, in particular multi-shaft test benches can be mentioned. Such an arrangement is shown in figure 6. In this case, a rotating test object 1, which can for example be a transmission, is connected via at least one further rotating load machine 2' via at least one further mechanical coupling shaft 3'. In this case, the at least one further rotating load machine 2' can be used as an actuator together with the already existing rotating load machine 2 in the control of the test bench device 4. In this case, the angular velocity ω of the test object ω P and the rotational torque T of the test piece P The present estimates of may be used without limitation.

Claims

1. A method for adjusting a test bench apparatus (4), in which a rotating test object (1) is connected to a rotating load (2) via a mechanical connecting shaft (3) and at least one predominant angular velocity is measured in the test bench apparatus (4), comprising the steps of: The rotational behavior of the test bench device (4), i.e. at least the angular velocity to be measured and the angular velocity of the test object (1) that prevails (ω Ｐ ) is modeled by a first system of differential equations, - the rotational torque (T Ｐ ) is modeled by a second system of differential equations, and a rotational torque (T Ｐ ) is shown, and the rotational torque (T Ｐ ) are denoted as damped and / or undamped oscillators, - calculating the angular velocity (ω Ｐ ) and the rotational torque (T Ｐ ) is generated, the measured angular velocity is an input of the state observer, - based on the state observer, an estimate of the angular velocity of the test object (ω Ｐ ) and the estimated value of the rotational torque of the test piece (T^ Ｐ ) is calculated, - The calculated estimated angular velocity of the test object (ω^ Ｐ ) and the estimated rotational torque of the test piece (T^ Ｐ ) is used to adjust at least one adjusting angular velocity prevailing in the test bench device (4) and / or at least one adjusting rotational torque prevailing in the test bench device (4).

2. Based on the state observer, an estimate of the angular velocity of the test object (ω̂ Ｐ ) and the estimated value of the rotational torque of the test piece (T^ Ｐ ), plus the estimated shaft torque (T^ ＳＴ ) and / or the load angular velocity estimate (ω^ Ｄ 2. The method according to claim 1, further comprising the steps of: calculating an estimated angular velocity and / or an estimated torque for the test bench device; and determining whether the estimated angular velocity and / or the estimated torque for the test bench device are equal to or greater than the estimated angular velocity and / or the estimated torque for the test bench device.

3. The parameters of the second differential equation system, i.e., to adapt the second differential equation system to the changes in at least one rotational variable prevailing in the test bench device (4), are determined by the rotational torque (T Ｐ 3. The method according to claim 1, wherein the rotational speed of the test bench device is selected as a function of at least one rotational variable that is dominant in the test bench device and changes during operation of the test bench device in order to model the rotational speed of the test bench device.

4. 4. The method according to claim 3, characterized in that the parameters of the state observer, i.e. the parameters of the state observer generated on the basis of the first and second systems of differential equations in order to adapt the state observer to changes in at least one rotational variable prevailing in the test bench device (4), are selected as a function of at least one rotational variable prevailing in the test bench device (4), which changes during operation of the test bench device (4).

5. The rotating test object (1) is connected to at least one other rotating load (2') via at least one other mechanical connecting shaft (3'); and 3. The method according to claim 1 or 2, characterized in that the at least one further rotating load (2') is used together with the already existing rotating load (2) as an actuator for adjusting at least one adjusting angular velocity prevailing in the test bench device (4) and / or at least one adjusting rotational torque prevailing in the test bench device (4).

6. A test bench comprising a test bench device (4) and an automation system (5), in said test bench arrangement (4), a rotating test object (1) is connected to a rotating load (2) via a mechanical connecting shaft (3), said test bench arrangement (4) being designed to measure and determine at least one angular velocity prevailing in said test bench arrangement (4), The automation system (5) determines the rotational behavior of the test bench device (4), i.e. at least the measured angular velocities and the angular velocity (ω Ｐ ) is modeled by a first system of differential equations, The automation system (5) - the rotational torque (T Ｐ ) is modeled by a second differential equation system, and a rotational torque (T Ｐ ) and based on m other vibration subsystems of the second differential equation system, a rotational torque (T Ｐ ) as damped and / or undamped oscillators; - calculating the angular velocity (ω Ｐ ) and the rotational torque (T Ｐ ), the measured angular velocity being an input to the state observer; - based on the state observer, an estimate of the angular velocity of the test object (ω Ｐ ) and the estimated value of the rotational torque of the test piece (T^ Ｐ ) is calculated, - The calculated estimated angular velocity of the test object (ω^ Ｐ ) and the estimated rotational torque of the test piece (T^ Ｐ ) for adjusting at least one adjusting angular velocity prevailing in the test bench device (4) and / or at least one adjusting rotational torque prevailing in the test bench device (4).

Images