DE102013100964A1 - Method for actively damping torsional vibrations of a shaft of an engine, in particular a crankshaft of a reciprocating engine, and a corresponding arrangement for carrying out the method - Google Patents

Abstract

A method for actively damping torsional vibrations of a crankshaft (2) of a reciprocating piston engine (1) comprises the following method steps: (S1) acquiring input data by measuring operating states of the reciprocating piston engine (1); (S2) determining activation data on the basis of the input data recorded; and (S3) active damping of the torsional vibrations of the crankshaft (2) by controlling an actuator (8) that is operatively connected to the crankshaft (2) with the determined control data. An arrangement for carrying out the method has: a) a reciprocating piston engine (1) with a crankshaft (2) and an engine control unit (3); and b) a damping device (4) with a damping control device (9) for controlling the damping device (4), a sensor device (5) for detecting a speed (n) of the crankshaft (2) and an actuator (8) for damping torsional vibrations of the Crankshaft (2). The sensor device (5) and the actuator (8) are attached to the crankshaft (2) in operative connection with the latter.

Description

The invention relates to a method for actively damping torsional vibrations of a shaft of a machine, in particular a crankshaft of a reciprocating engine. The invention also relates to a corresponding arrangement for carrying out the method.

Torsional vibrations, also referred to as torsional vibrations, of a shaft of a machine are rotational nonuniformities that can be generated by fluctuations in the rotational speed of the shaft. This occurs in many dynamic operations of machines, e.g. Periodically or aperiodically occurring torques, for example by the drive of the shaft and / or by different loads of the functional units that are driven by the shaft arise. Torsional vibrations may cause the shaft, e.g. By torsional stresses, so stress in their strength that to achieve a certain fatigue strength appropriate dimensioning measures as well as a selection of higher quality materials is required.

The shafts are in particular crankshafts of reciprocating engines, which are e.g. Diesel, gasoline, or gas engines are. Hydraulic, pneumatic and steam engines can also be reciprocating engines. A reciprocating engine may e.g. as a drive for a vehicle, a construction machine or the like. or used as a stationary or portable drive for a variety of drive purposes.

At present, passive torsional vibration dampers are used to reduce stresses in crankshafts. These are, for example, flywheels and special passive dampers, as examples for illustration, for example, in the documents EP 1266152 B1 . US 6,026,709 A . US 5,637,041 A are described.

DE 10 2010 046 849 B4 describes a sensor-based control of vibrations in slender continuums, especially torsional vibrations in deep drill strings. A theory for the calculation of running waves based on two measuring points is given.

In the wake of ever-increasing requirements for small construction with the same efficiency, low weight and low cost, especially in the vehicle sector, there is an increasing demand for effective damping devices.

It is therefore the object of the present invention to provide an improved method for damping torsional vibrations of a shaft of a machine.

Another object is to provide an improved arrangement for carrying out such a method.

The object is achieved by a method having the features of claim 1 and by arrangements having the features of claims 21 and 25.

A basic idea of the invention is that active damping of the torsional vibrations of the crankshaft is carried out by activating an actuator which is operatively connected to the crankshaft with specific activation data.

Accordingly, a method according to the invention for actively damping torsional vibrations of a shaft of an engine, in particular a crankshaft of a reciprocating engine, comprises the following method steps: (S1) detecting input data by measuring operating states of the reciprocating engine; (S2) determining driving data based on the detected input data; and (S3) actively dampening the torsional vibrations of the crankshaft by driving an actuator operatively connected to the crankshaft with the determined drive data.

This advantageously ensures that the damping of the torsional vibrations of the shaft, in particular crankshaft, is not performed by a passive system, but by an actuator. The actuator is supplied with drive data determined from input data obtained by measurements of the operating state of the crankshaft and the engine associated with the crankshaft, respectively.

The operating state of the crankshaft with the associated machine or reciprocating piston engine can be detected on the basis of data of the rotational speed and angular position of the crankshaft and the current load of the machine.

The inventive method can be implemented with any actuators, as long as they allow the application of an alternating torque with an application-dependent amplitude and bandwidth.

An arrangement according to the invention for carrying out the method comprises: a) a machine having a shaft, in particular a reciprocating piston engine with a crankshaft, and an engine control unit; and b) a damping device with a damping control device for controlling the damping device, a sensor device for detecting a rotational speed of the crankshaft and an actuator for damping torsional vibrations of the crankshaft. The sensor device and the actuator are in Operative connection with the crankshaft attached to this.

The active damping of the torsional vibrations offers the advantage of a maximum reduction in the amplitudes of the torsional vibration and thus the voltages in the associated shaft.

In addition, a reduction in the amplitudes of the torsional vibrations over the entire frequency range in contrast to a passive torsional vibration damper is possible. The passive torsional vibration damper only dampens resonance frequencies of the crankshaft. The active system according to the invention can detect vibrations at any frequencies, i. also outside the resonance, dampen. This property is especially advantageous when e.g. not only the first, but other natural frequencies are excited by the course of the gas pressure above the speed in a reciprocating engine. Then a damping with a conventional damper is no longer possible, it would then be used at least two different conventional damper.

Yet another advantage results from a reduction in the installation space and / or by using already existing actuators. Depending on the actuator used, a reduction of the required installation space can be achieved. If there are already active elements in the powertrain (e.g., in hybrid drives), it may be possible to use these elements to dampen vibration, thereby circumventing the need for a conventional damper.

The method according to the invention is based on calculating the torsional vibrations in the crankshaft into two running shafts and extracting energy from the system (crankshaft and reciprocating piston engine) by compensating for the shaft in the actuator running in the direction of the actuator. By compensating for the shaft running in the actuator in the actuator, a reflection of the wave is prevented in the system, thereby depriving the system of energy, the system thus damped. The theory for calculating running waves based on two measurement points is eg in the document DE 10 2010 046 849 B4 described. In contrast, however, the generated based on the Wellenendekomposition data for driving the actuator during operation of the damping device for damping the crankshaft are not calculated in real time in the inventive method. It is used on previously stored control data.

For this purpose, in one embodiment, determining drive data of the method comprises the following substeps: (S2.1) determining the current speed and the current angular position of the crankshaft; (S2.2) determining a current engine load of the current operating state of the reciprocating engine; and (S2.3) determining the drive data by reading associated previously stored drive data based on the determined rotational speed of the crankshaft, angular position of the crankshaft, and engine load.

Advantageously, the activation data for the actuator need not be calculated in real time as described above. They have previously been stored in a memory device and only need to be read from the memory device on the basis of the specific current input data speed, angular position and engine load. The drive data is pre-set, e.g. on a test bench and / or by a simulation program, generated and stored. This is possible because the machine / shaft system, due to known excitation and increased damping in any operating condition, i. at any possible combination of engine speed and engine load, can be considered as quasi-stationary. It is therefore possible to record the required control data once.

In the sub-step (S2.1), the determination of the current rotational speed and the current angular position of the crankshaft takes place on the basis of measured data of a sensor device. Furthermore, in sub-step (S2.2), the determination of a current engine load is carried out on the basis of data from an engine control unit of the reciprocating piston engine. This acquisition of measurement data is easy.

In a further embodiment, in the sub-step (S2.3), the previously stored control data are read from a three-dimensional look-up table. An advantage is that instead of two high-precision sensors, only one sensor with significantly lower accuracy is required. Based on this sensor or this sensor device, the rotational speed and the instantaneous angular position of the crankshaft can be determined. The angular position (approximately opposite TDC) is required in order to apply the control in the correct phase for damping the torsional vibrations. The engine load also required can be easily taken from the data of the engine or engine management.

In a still further embodiment, energy recovery by means of the actuator is carried out in method step (S3) during active damping of the torsional vibrations of the crankshaft. Thus, the energy extracted from the system by damping, for example, as electrical energy in a rechargeable battery, eg in a vehicle battery, stored and reused.

This achieves a reduction of heat emission and independence from the ambient temperature. A conventional damper converts the energy of the torsional vibration into heat and releases it to the environment, i. the energy is dissipated across the system boundaries. Depending on the actuator used, in the active damping device according to the invention, the recovery of the vibration energy is e.g. possible in the form of electrical energy. Accordingly, no heat is dissipated in such a case. Furthermore, it may be that temperatures occur due to the installation situation, which can lead to a very rapid deterioration of the silicone oil in viscosity torsional vibration dampers and reduce their function. An actuator that is less sensitive to temperature, however, can be used.

In a further embodiment, the method for generating the previously stored drive data comprises the following method steps: (S'1) detecting input data of operating states of the reciprocating engine; (S'2) generating drive data based on the detected input data; and (S'3) storing the thus generated drive data in a storage medium. The saving or recording can be done once. Copies may be made for the respective storage devices of the damping devices for practical use.

Generating control data comprises the following sub-steps: (S'2.1) determining the current speed and the current angular position of the crankshaft, and determining an engine load of the current operating state of the reciprocating engine; (S'2.2) calculating a wave decomposition with the thus determined measurement data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition.

The required control data can be done once from a detection of input data of operating states of the reciprocating engine on a test bench. In this case, in the partial step (S'2.1), the determination of the current rotational speed and the current angular position of the crankshaft is carried out on the basis of measured data from two sensor devices, whereby the determination of a current engine load is carried out on the basis of data of an engine control device of the reciprocating piston engine.

Alternatively or additionally, it is also possible for the detection of input data of operating states of the reciprocating piston engine to comprise acquisition of data from a simulation method of operating states of the reciprocating piston engine.

In one embodiment, the generation of drive data comprises the following substeps: (S'2.1) determining the current speed and the current angular position of the crankshaft, and determining an engine load of the current operating state of the reciprocating engine from the data of the simulation method; (S'2.2) calculating a wave decomposition with the thus determined data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition.

In this case, in the sub-step (S'2.2), the calculation of the wave decomposition into two running waves takes place in real time.

Further, in the substep (S'2.3), the determination of the drive data is performed by using the shaft of the two traveling waves of the shaft decomposition calculation, which is incident on the actuator in a longitudinal direction of the crankshaft.

It is also possible in a variant that the detected input data are initially stored temporarily and the drive data to be stored once are subsequently calculated from these temporarily stored input data.

In a further embodiment, the storage of the generated drive data in the storage medium takes place as a three-dimensional look-up table. Of course, another type, e.g. a three- or n-dimensional matrix are generated.

Thus, the drive data required to drive the actuator may be pre-generated for each possible combination of speed and engine load and recorded for future use at any time. Thus, it is possible that for each type of engine or reciprocating engine, the driving data can be previously recorded.

This method of reading previously stored drive data was examined using a simulation model. The results using the drive data stored in the look-up table are comparable to the results of real-time control.

In one embodiment of the arrangement for this method, it is provided that the sensor device is designed as an incremental encoder. This incremental encoder may have, for example, a Hall sensor. Of course, another design, such as an optical sensor is possible. One The particular advantage here is that the accuracy of the sensor device compared to the prior art has only a low accuracy, namely a resolution of 360 increments per revolution of the crankshaft.

In addition, in this embodiment of the arrangement, the damping control device of the damping device has at least one memory device with the previously stored control data for the actuator. The previously stored control data are previously recorded, calculated and stored once as described above. The control device can thus contain a copy of the once generated drive data.

In one embodiment, the actuator is designed as an electric motor, torque motor or piezoelectric actuator. While any actuator designs may be used, the actuator must enable the application of alternating torque with application-dependent amplitude and bandwidth.

In an alternative embodiment of the method, the determination of drive data comprises the following sub-steps: (S'2.1) determining the current speed and the current angular position of the crankshaft, and determining an engine load of the current operating state of the reciprocating engine; (S'2.2) calculating a wave decomposition with the thus determined measurement data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition.

Thus, an active damping of the torsional vibrations with two sensor devices and real-time calculation of the control data from the input data can be done. However, in comparison with the prior art in the method according to the invention for controlling the torsional vibrations, the drive of the shaft, ie the machine or reciprocating piston engine, is not supplied with the drive data, but instead a separate actuator is used which is part of a damping device.

Thus, it is provided that in the partial step (S'2.1) the determination of the current rotational speed and the current angular position of the crankshaft takes place on the basis of measured data from two sensor devices, wherein the determination of a current engine load is carried out on the basis of data of an engine control device of the reciprocating piston engine. Furthermore, in the partial step (S'.2.2), the calculation of the wave decomposition into two running waves takes place in real time. In the sub-step (S'2.3), the determination of the driving data is performed by using the wave of the two traveling waves of the shaft decomposition calculation converging on the actuator in a longitudinal direction of the crankshaft.

Also in this variant, it is provided that in the process step (S3) in the active damping of torsional vibrations of the crankshaft energy recovery by means of the actuator is performed, the advantages of which have already been described above.

Accordingly, an arrangement for carrying out the method according to the alternative embodiment described above comprises: a) a machine having a shaft, in particular a reciprocating piston engine with a crankshaft, and an engine control unit; and b) a damping device with a damping control device for controlling the damping device, two sensor devices for detecting a rotational speed of the crankshaft and an actuator for damping torsional vibrations of the crankshaft. The two sensor devices and the actuator are mounted in operative connection with the crankshaft, and the two sensor devices are arranged at an axial distance from each other. The actuator is part of the damping device and serves to dampen the torsional vibrations of the shaft or crankshaft.

In one embodiment, the sensor devices are designed as incremental encoders. In this case, the sensor devices each have a high resolution.

It is further provided that the damping control device of the damping device has at least one control device for real-time calculation of Wellenendekompositionen.

Again, in one embodiment, the actuator as an electric motor, torque motor or piezoelectric actuator, where it allows the application of an alternating torque with an application-dependent amplitude and bandwidth.

In both embodiments of the arrangements according to the invention, the damping control device of the damping device has at least one drive device for the actuator.

In addition, it is provided in both embodiments of the arrangements according to the invention that the damping device has a device for energy recovery, which cooperates with the actuator.

The method for the active damping of torsional vibrations of a shaft and the arrangements for carrying out this method and its variants offer over the prior art a reduced space, a greater reduction of the vibration amplitudes of the torsional vibrations of the shaft not only at certain speeds, but over the entire frequency range. In addition, energy recovery is possible.

The invention will now be explained in more detail by means of embodiments with reference to the accompanying drawings. Hereby shows:

1 a schematic representation of an arrangement of a reciprocating engine with a damping device according to the invention according to a first embodiment;

2 a schematic representation of the arrangement of a reciprocating engine with the damping device according to the invention according to a second embodiment;

3 to 5 schematic flow diagrams of embodiments of inventive method for actively damping torsional vibrations;

6 a schematic flow diagram of a method according to the invention for generating drive data;

7 a schematic graphical representation of torsional vibrations; and

8th - 9 schematic diagrams of undamped and damped torsional vibrations.

Identical components or functional units with the same function are indicated by the same reference numerals in the figures.

1 shows a schematic representation of an arrangement of a reciprocating engine 1 with a damping device according to the invention 4 according to a first embodiment.

The arrangement includes the reciprocating engine 1 with an engine control unit 3 and with the damping device 4 ,

The reciprocating engine 1 is for example a diesel, petrol or gas engine. For example, hydraulic, pneumatic and steam engines as reciprocating engine 1 be educated. The reciprocating engine 1 can eg as a drive for a vehicle, a construction machine or the like. or used as a stationary or portable drive for a variety of drive purposes.

A motor housing 1a the reciprocating engine 1 is with a crankshaft 2 shown schematically. The crankshaft 2 is from the reciprocating engine 1 powered and is with a front end 2a from the motor housing 1a led out and has a crankshaft axis 2 B on which the crankshaft 2 in one direction of rotation 2c during operation of the reciprocating engine 1 rotates. The crankshaft 2 extends in a longitudinal direction 2d to her front end 2a and in a longitudinal direction opposite thereto 2e to her rear end, not shown.

The engine control unit 3 is via an engine control unit connection 3a , which is given as representative of different connections, with the reciprocating engine 1 in connection.

The damping device 4 is for active damping of torsional vibrations of the crankshaft 2 the reciprocating engine 1 intended. The damping device 4 includes a damping control device 9 , a sensor device 5 and an actor 8th , The damping control unit 9 stands with the engine control unit 3 , the sensor device 5 and the actor 8th in active connection. The damping device 4 and their operation will be described in detail below.

The sensor device 5 forms an incremental encoder and includes a sensor wheel 6 and a pickup 7 , The sensor wheel 6 is in the area of the front end 2a the crankshaft 2 applied rotatably on this. The sensor wheel 6 is a kind of gear, its teeth with the transducer 7 so interact without contact, that the rotation of the crankshaft 2 around its crankshaft axis 2 B Here digitally counted by counting the pulses generated by the teeth in the transducer per unit time as a speed. In addition, an angular position of the crankshaft 2 thus detectable, with the resolution of the number of teeth of the sensor wheel 6 depends. In this case, a relatively low accuracy of eg 360 increments / revolution of the crankshaft 2 suffice. This achieves a resolution of 1 °. The pickup 7 may be a Hall sensor, for example. Of course, the sensor device 5 be constructed differently, for example with an optical pickup 7 ,

The actor 8th is at the front end 2a the crankshaft 2 attached and rotatably connected to this. In another embodiment, not shown, the actuator 8th with the crankshaft 2 and be connected to a vehicle chassis, also not shown. The actor 8th can an electric motor, eg a so-called torque motor, with high torque (in the range of a cylinder torque of the reciprocating engine 1 ) with high bandwidth. Alternatively, a piezo actuator with a corresponding torque can also be used.

The damping control unit 9 here has a control device 10 , a storage device 11 and a drive device 12 on. The control device 10 is with the engine control unit 3 via an engine control unit connection 3b connected.

In addition, the control device 10 to the storage device 11 connected and communicates with the sensor device 5 via a pickup line 7a with the picker 7 the sensor device 5 in connection. In addition, the control device 10 with the drive device 12 connected to which the actuator 8th with a control line 12a connected.

The damping device 4 receives input data about the operating state of the reciprocating engine 1 and the crankshaft 2 both from the engine control unit 3 as well as from the sensor device 5 , These input data are sent to the controller 10 of the damping control unit 9 delivered. Based on these input data, the controller determines 10 Control data for the drive device 12 , The control device 10 in this embodiment, determines the driving data by corresponding to these input data by means of the input data, respectively, in advance in the memory device 11 stored drive data from the storage device 11 reads out and to the control device 12 forwards. The drive device 12 supplies the actuator based on this control data 8th with control signals. The actor 8th then acts on the crankshaft 2 on, that their torsional vibrations are damped by compensation of the wave reacting to the actuator.

For this purpose, the associated method is further explained below, which is based on the torsional vibrations of the crankshaft 2 divide into two running waves and deprive the system of energy by moving longitudinally 2d towards the actor 8th current wave in the actuator 8th is compensated. By compensating this wave in the actuator 8th is a reflection of the wave in the system, ie in the crankshaft 2 longitudinal 2e in the reciprocating engine 1 , prevented in. The system is thereby deprived of energy, thus the system is attenuated. The theory for calculating running waves based on two measurement points is eg in the document DE 10 2010 046 849 B4 described in detail.

The input data includes the speed of the crankshaft 2 , the angular position of the crankshaft 2 , about in terms of the TDC (top dead center), as well as the current engine load of the reciprocating engine 1 , The sensor device 5 provides the speed of the crankshaft 2 , The instantaneous angular position of the crankshaft 2 is from the controller 10 determined from the input data of the speed. The data of the current engine load receives the control device 10 from the engine control unit 3 (Engine Management). These three data are from the controller 10 now used in a three-dimensional look-up table in the storage device 11 select and read the associated control data.

The in the storage device 11 stored three-dimensional look-up table has the respective control data for the actuator for each possible combination of speed and motor load and angular position 8th for damping the torsional vibrations of the crankshaft 2 on. This driving data is previously acquired and stored. This is possible eg on a test bench or with a simulation, since the system of the reciprocating piston engine 1 with the crankshaft 2 due to known excitation and increased damping in each operating state, ie at every possible combination of crankshaft speed 2 and engine load can be assumed as quasi-stationary. It is therefore possible to record the required control data for each operating state once and then in the form of the three-dimensional look-up table in a memory device which can be read out at any time 11 save.

The advantage of the look-up table in this first embodiment of the damping device 4 lies in the fact that only the one sensor device 5 is needed with significantly lower accuracy. In addition, the data generated on the basis of the shaft decomposition must be used to control the actuator 8th for damping the crankshaft 2 can not be calculated in real time. The angular position of the crankshaft 2 , approximately opposite OT, is needed to control the actuator 8th for damping the torsional vibrations of the crankshaft 2 Apply in the correct phase.

2 shows a schematic representation of an arrangement of the reciprocating engine 1 with the damping device according to the invention 4 according to a second embodiment.

In contrast to the first embodiment according to 1 Here are two sensor devices 5 and 5 ' intended. The first sensor device 5 is constructed as in the first embodiment, but provided with a higher accuracy. Also the second sensor device 5 ' has a very high accuracy. The sensor wheel 6 ' the second sensor device 5 ' is at an axial distance 6a longitudinal 2e from the sensor wheel 6 the first sensor device 5 arranged. The pickup 7 ' the second sensor device 5 ' is via a second sensor line 7a ' with the control device 10 of the damping control unit 9 connected.

In this second embodiment, the memory device includes 11 no previously calculated activation data, but serves for general storage purposes, eg temporary storage of calculation results.

The control device 10 leads in contrast to the first embodiment, a real-time calculation of the drive data for the actuator 8th from the input data. In this case, a real-time-capable calculation of the wave decomposition is carried out, the input data being the measurement data of the sensor devices 5 . 5 ' and the engine control unit 3 (and / or other existing sensors) used (continuous control).

It also serves 2 to explain the detection of the input data and generation of the drive data to be stored for the actuator 8th ,

In this case, the reciprocating engine 1 on a test bench. The two high-precision sensor devices 5 and 5 ' are like in 2 shown on the crankshaft 2 rotatably in the distance 6a appropriate. The actor 8th is not on the damping control unit 9 connected. The damping control unit 9 is with the control device 10 now used as a recording device.

The drive data are in this structure by a single measurement on the reciprocating engine 1 on the engine test bench using the high-precision sensor devices 5 and 5 ' and a real-time or subsequent computation of the wave decomposition that generates input data using the measurement data. For the subsequent calculations, intermediate storage of the input data can be made. After the calculation, the thus generated driving data is stored in the memory device 11 or stored in a suitable removable storage medium (not shown).

The control data may deviate from 2 without the reciprocating engine 1 and the sensor devices 5 . 5 ' also by a simulation of the torsional vibrations of the reciprocating engine 1 and a calculated calculation of the Wellenendekomposition be generated. The calculation of the wave decomposition uses simulation data, eg from a computer program, as input data.

The drive data generated in the above-described two ways then becomes a function of engine load, rotational speed of the crankshaft 2 and angular position of the crankshaft 2 stored in a three-dimensional look-up table.

3 shows a general, schematic flowchart of a method according to the invention for actively damping torsional vibrations of the crankshaft 2 the reciprocating engine 1 ,

In a first method step S1, input data of the reciprocating piston engine are acquired 1 ,

A determination of activation data is undertaken in a second method step S2 on the basis of the acquired input data. This can eg the control device 10 of the damping control unit 9 carry out.

Finally, the actor 8th in a third method step S3 on the basis of the thus determined control data for damping the torsional vibrations of the crankshaft 2 the reciprocating engine 1 driven.

A first embodiment of the method according to the invention 4 in a schematic flow diagram.

In the first method step S1, the acquisition of input data of the reciprocating engine takes place 1 , Thus, a current speed n of the crankshaft 2 the reciprocating engine 1 from the sensor device 5 detected. An engine load of the reciprocating engine 1 is through the engine control unit 3 delivered.

The method step S2 determining drive data is divided into three sub-steps. In a first sub-step S2.1 is based on the input data of the sensor device 5 set the speed n and the current angular position α of the crankshaft 2 certainly. The engine load of the current operating state is in a second sub-step S2.2 from the engine control unit 3 accessed. By means of these three components, in a third sub-step S2.3, the associated control data is transferred from the memory device to the memory device 11 previously stored look-up table.

In the third method step S3, the actuator 8th with the from the in the storage device 11 previously stored look-up table read control data for damping the torsional vibrations of the crankshaft 2 the reciprocating engine 1 driven.

A second embodiment of the method according to the invention is shown in a schematic flow diagram of 5 shown.

In a first method step S'1 takes place as in the first embodiment 3 and 4 the detection of the input data of the reciprocating engine 1 as the current speed n of the crankshaft 2 and the engine load from the engine control unit 3 ,

The method step S'2 determining drive data is here also divided into three sub-steps, but these differ from those of the first embodiment.

In a first sub-step S'2.1 is based on the input data of the sensor devices 5 and 5 ' the speed n and the current angular position α of the crankshaft 2 certainly. In addition, the engine load of the current operating state from the engine control unit 3 accessed. These input data are used as measurement data for a wave decomposition computation in a second sub-step S'2.2, the rotational oscillations being split up into two running waves in real time. In this case, in a third sub-step S'2.3 the longitudinal direction 2d on the actor 8th incoming wave for determining the drive data for the actuator 8th used.

In the third method step S'3, the actuator 8th with the control data calculated in real time for damping the torsional vibrations of the crankshaft 2 the reciprocating engine 1 driven.

6 shows a schematic flow diagram of a method according to the invention for generating and storing the drive data.

In a first method step S'1, input data is acquired. In one embodiment, the input data of a reciprocating engine 1 on a test bench as the current speed n of the crankshaft 2 and the engine load from the engine control unit 3 measured in real time. In one variant, the input data are output data of a simulation, for example of a computer simulation program of the torsional vibrations of a crankshaft 2 a reciprocating engine 1 ,

In a method step S'2 activation data are generated. For this purpose, three sub-steps are provided.

In a first sub-step S'2.1 is based on the input data, eg the sensor devices 5 and 5 , 'the speed n and the current angular position α of the crankshaft 2 certainly. In addition, the engine load of the current operating state from the engine control unit 3 retrieved or read in as simulation data. These input data are used as measurement data for a wave decomposition computation in a second sub-step S'2.2, the rotational oscillations being split up into two running waves in real time. In this case, in a third sub-step S'2.3 the longitudinal direction 2d on the actor 8th incoming wave used to determine the drive data.

In the third method step S'4, the activation data thus generated are stored in a storage medium. In this case, the storage can take place, for example, as a three-dimensional look-up table. This look-up table can then be used for applications in damping devices 4 as a copy in the respective storage device 11 of the damping control unit 9 get saved.

7 shows a schematic diagram of torsional vibrations of a crankshaft 2 a reciprocating engine 1 , which in this example is an eight-cylinder V-shaped diesel engine with turbocharging.

Measured values of relative angular amplitudes are plotted as deflection A over the speed n (rpm) of the motor. A variety of waveforms is a cumulative curve 13 summarized, which lies above the individual measured curves. There are many amplitude peaks, of which several local maxima 13a . 13b . 13c . 13d are clearly visible. The local maximum 13a is approximately at the speed 2500 rpm. The local maxima 13b and 13c occur at about the speeds 3900 U / min and 4300 U / min. The largest local maximum 13d is approximately at the speed 4850 rev / min recorded.

With the damping device according to the invention 4 It is possible to significantly dampen these torsional vibrations with their deflections A. For this purpose investigations were carried out by means of a simulation model.

In addition shows 8th a schematic diagram of undamped torsional vibrations. And 9 shows the result when using the damping device 4 as a schematic representation of the damped torsional vibrations.

In both 8th and 9 in each case the deflection A is plotted against the rotational speed n. 8th provides a variety of torsional curves in the form of envelopes 14 with the respective local maxima similar to in 7 dar. With switched damping device 4 results in the envelope 15 in 9 , At this muted envelope 15 It can be clearly seen that all local maxima above the speed of 2100 rpm no longer exist. Only in the low speed range at about 1200 rpm, a maximum can be seen, but which appears relatively flattened.

In addition, it can be seen that all local maxima, without the application of the damping device 4 (or with the damping device switched off 4 ), are attenuated, regardless of what speed n or frequency they occur. It is done with the damping device 4 a strong reduction of the vibration deflections or amplitudes over the entire frequency range or speed range. In addition, there is a reduction of stresses in the crankshaft 2 possible.

It has been shown in this simulation model that the results with the activated damping device 4 when using the first embodiment with those in the look-up table in the storage device 11 stored driving data comparable to the results in the real-time control according to the second embodiment of the damping device 4 are.

The invention is not limited to the embodiments described above. It is modifiable within the scope of the appended claims.

So it is conceivable that the actor 8th can be used for energy recovery. Depending on the type of actuator 8th , For example, as a piezoelectric actuator, the vibrational energy extracted from the system can be recovered, for example in the form of electrical energy. This is the actor 8th connected to a corresponding circuit (not shown) corresponding to that of the actuator 8th generated electrical energy stores eg in an accumulator.

For detecting the angular position α of the crankshaft 2 can also be provided a separate sensor. It is also possible that these data already in the engine control unit 3 are available so that it can be used.

In one embodiment can already active elements in a drive train, which with the crankshaft 2 is present (eg in a hybrid drive). It may possibly be possible to use these elements for vibration damping with.

The actor 8th can also be at a different location of the crankshaft 2 to be appropriate. It is also conceivable that the damping device 4 can also be used for damping torsional vibrations in shafts other than reciprocating engines. For example, in machines whose operating conditions can be assumed as quasi-stationary, the damping device 4 be used according to the first embodiment. Also the second embodiment with two sensor devices 5 . 5 ' Can be used on shafts of other machines. This creates the torsional vibrations of the shaft in the machine, and the actuator is not used to drive the shaft, but for active damping.

LIST OF REFERENCE NUMBERS

1

 reciprocating engine

1a

 engine

2

 crankshaft

2a

 front end

2 B

 crankshaft axis

2c

 direction of rotation

2d, 2e

 longitudinal direction

3

 Engine control unit

3a, 3b

 Engine control units connection

4

 damping device

5, 5 '

 sensor device

6, 6 '

 sensor wheel

6a

 distance

7, 7 '

 pickup

7a, 7'a

 Transducer line

8th

 actuator

9

 Damping control unit

10

 control device

11

 memory device

12

 driving

12a

 drive line

13

 cumulative curve

13a-d

 Local maximum

14, 15

 envelope

A

 deflection

n

 Engine speed

S ...

 step

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1266152 B1 [0004]
• US 6026709 A [0004]
• US 5637041 A [0004]
• DE 102010046849 B4 [0005, 0019, 0070]

Claims (30)

Method for actively damping torsional vibrations of a shaft of a machine, in particular a crankshaft ( 2 ) a reciprocating engine ( 1 ), comprising the following method steps: (S1) acquiring input data by measuring operating states of the reciprocating piston engine ( 1 ); (S2) determining driving data based on the detected input data; and (S3) actively damping the torsional vibrations of the crankshaft ( 2 ) by driving one with the crankshaft ( 2 ) Actuator ( 8th ) with the particular drive data. A method according to claim 1, characterized in that the determination of drive data comprises the following substeps. (S2.1) Determining the Current Speed (n) and the Current Angular Position (α) of the Crankshaft ( 2 ); (S2.2) determining a current engine load of the current operating state of the reciprocating engine ( 1 ); and (S2.3) determining the drive data by reading associated, previously stored drive data based on the determined speed (n) of the crankshaft ( 2 ), Angular position (α) of the crankshaft ( 2 ) and engine load. A method according to claim 2, characterized in that in the sub-step (S2.1) determining the current speed (n) and the current angular position (α) of the crankshaft ( 2 ) based on measurement data of a sensor device ( 5 ) he follows. A method according to claim 2 or 3, characterized in that in the sub-step (S2.2) determining a current engine load based on data from an engine control unit ( 3 ) of the reciprocating engine ( 1 ) is carried out. Method according to one of claims 2 to 4, characterized in that in the sub-step (S2.3), the read-out of the previously stored control data from a three-dimensional look-up table. Method according to one of the preceding claims, characterized in that in the method step (S3) during active damping of the torsional vibrations of the crankshaft ( 2 ) an energy recovery by means of the actuator ( 8th ) is carried out. Method according to one of claims 2 to 6, characterized in that generating the previously stored control data comprises the following method steps: (S'1) detecting input data of operating states of the reciprocating piston engine ( 1 ); (S'2) generating drive data based on the detected input data; and (S'3) storing the thus generated drive data in a storage medium. A method according to claim 7, characterized in that the generation of control data comprises the following sub-steps: (S'2.1) determining the current rotational speed (n) and the current angular position (α) of the crankshaft ( 2 ), and determining an engine load of the current operating state of the reciprocating engine ( 1 ); (S'2.2) calculating a wave decomposition with the thus determined measurement data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition. Method according to claim 7 or 8, characterized in that the acquisition of input data of operating states of the reciprocating engine ( 1 ) on a test bench. A method according to claim 9, characterized in that in the sub-step (S'2.1) determining the current rotational speed (n) and the current angular position (α) of the crankshaft ( 2 ) based on measurement data from two sensor devices ( 5 . 5 ' ), wherein the determination of a current engine load based on data of an engine control unit ( 3 ) of the reciprocating engine ( 1 ) is carried out. Method according to claim 7, characterized in that the acquisition of input data of operating states of the reciprocating engine ( 1 ) acquisition of data from a simulation method of operating states of the reciprocating engine ( 1 ) having. A method according to claim 11, characterized in that the generation of control data comprises the following sub-steps: (S'2.1) determining the current rotational speed (n) and the current angular position (α) of the crankshaft ( 2 ), and determining an engine load of the current operating state of the reciprocating engine ( 1 ) from the data of the simulation process; (S'2.2) calculating a wave decomposition with the thus determined data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition. Method according to claim 8 or 12, characterized in that in the sub-step (S'.2.2) the calculation of the wave decomposition into two running waves takes place in real time. A method according to claim 13, characterized in that in the substep (S'2.3) determining the drive data by using the in a longitudinal direction ( 2d ) of the crankshaft ( 2 ) on the actuator ( 8th ) incoming wave of the two running waves of the Wellenendekompositionsberechnung is performed. Method according to one of claims 7 to 14, characterized in that the storage of the generated drive data in the storage medium is carried out as a three-dimensional look-up table. A method according to claim 1, characterized in that the determination of drive data comprises the following substeps. (S'2.1) Determining the Current Speed (n) and the Current Angular Position (α) of the Crankshaft ( 2 ), and determining an engine load of the current operating state of the reciprocating engine ( 1 ); (S'2.2) calculating a wave decomposition with the thus determined measurement data as input data; and (S'2.3) determining the drive data based on the calculated results of the wave decomposition. A method according to claim 16, characterized in that in the sub-step (S'2.1) determining the current speed (n) and the current angular position (α) of the crankshaft ( 2 ) based on measurement data from two sensor devices ( 5 . 5 ' ), wherein the determination of a current engine load based on data of an engine control unit ( 3 ) of the reciprocating engine ( 1 ) is carried out. Method according to claim 16 or 17, characterized in that in the sub-step (S'.2.2) the calculation of the wave decomposition into two running waves takes place in real time. A method according to claim 18, characterized in that in the substep (S'2.3) determining the drive data by using the in a longitudinal direction ( 2d ) of the crankshaft ( 2 ) on the actuator ( 8th ) incoming wave of the two running waves of the Wellenendekompositionsberechnung is performed. Method according to one of claims 16 to 19, characterized in that in the method step (S3) during active damping of the torsional vibrations of the crankshaft ( 2 ) an energy recovery by means of the actuator ( 8th ) is carried out. Arrangement for carrying out the method according to one of claims 1 to 15, comprising: a) a machine having a shaft, in particular a reciprocating piston machine ( 1 ) with a crankshaft ( 2 ), and an engine control unit ( 3 ); and b) a damping device ( 4 ) with a damping control device ( 9 ) for controlling the damping device ( 4 ), a sensor device ( 5 ) for detecting a rotational speed (n) of the crankshaft ( 2 ) and an actuator ( 8th ) for damping torsional vibrations of the crankshaft ( 2 ); wherein the sensor device ( 5 ) and the actuator ( 8th ) in operative connection with the crankshaft ( 2 ) are arranged. Arrangement according to claim 21, characterized in that the sensor device ( 5 ) is designed as an incremental encoder. Arrangement according to claim 22, characterized in that the sensor device ( 5 ) a resolution of 360 increments per revolution of the crankshaft ( 2 ) having. Arrangement according to one of claims 21 to 23, characterized in that the damping control device ( 9 ) of the damping device ( 4 ) at least one storage device ( 11 ) with previously stored control data for the actuator ( 8th ) having. Arrangement for carrying out the method according to one of Claims 16 to 20, comprising: a) a machine having a shaft, in particular a reciprocating piston engine ( 1 ) with a crankshaft ( 2 ), and an engine control unit ( 3 ); and b) a damping device ( 4 ) with a damping control device ( 9 ) for controlling the damping device ( 4 ), two sensor devices ( 5 . 5 ' ) for detecting a rotational speed (n) of the crankshaft ( 2 ) and an actuator ( 8th ) for damping torsional vibrations of the crankshaft ( 2 ); wherein the two sensor devices ( 5 . 5 ' ) and the actuator ( 8th ) in operative connection with the crankshaft ( 2 ) are attached thereto, and wherein the two sensor devices ( 5 . 5 ' ) with each other at an axial distance ( 6a ) are arranged to each other. Arrangement according to claim 25, characterized in that the sensor devices ( 5 . 5 ' ) are designed as incremental encoders. Arrangement according to claim 25 or 26, characterized in that the damping control device ( 9 ) of the damping device ( 4 ) at least one control device ( 10 ) for real-time calculation of Wellenendekompositionen. Arrangement according to one of claims 21 to 27, characterized in that the actuator ( 8th ) Is designed as an electric motor, torque motor or piezoelectric actuator. Arrangement according to one of claims 21 to 28, characterized in that the damping control device ( 9 ) of the damping device ( 4 ) at least one drive device ( 12 ) for the actuator ( 8th ) having. Arrangement according to one of claims 21 to 29, characterized in that the damping device ( 4 ) has a device for energy recovery, which with the actuator ( 8th ) cooperates.

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