METHOD AND DEVICE FOR DETERMINING ONE OR MORE ROTATIONAL SPEEDS OF A TURBOCHARGING DEVICE, IN PARTICULAR FOR AN INTERNAL COMBUSTION ENGINE

• US 20100332180A1
• Filed: 05/18/2010
• Published: 12/30/2010
• Est. Priority Date: 05/20/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Lerchenmueller, Klaus, Eichel, Dirk, SEIDEL, Juergen, Wendt, Juergen, Opitz, Bernhard, Kassner, Uwe, Laubender, Jochen, Grossmann, Alex, Hofmann, Dirk
• Granted Patent: US 8,504,321 B2
• Time in Patent Office: Days
• US Class Current: 702/145
• CPC Class Codes: F02B 2039/168 the rotational speed of pump or exhaust drive being limited
• CPC Class Codes: F02B 39/16 Other safety measures for, or other control of, pumps
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: G01P 3/48 by measuring frequency of generated current or voltage in general G01R23/00
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method is described for determining information about a rotational speed of a compressor, in particular a turbocharger, by providing a measuring signal, in particular a microwave measuring signal, which is directed at a compressor impeller of the compressor, so that the measuring signal is reflected on revolving blades of the compressor impeller, detecting the measuring signal reflected by one or more blades, and determining the information about the rotational speed as a function of the reflected measuring signal.

Claims

1. A method for determining information about a rotational speed of a compressor, which is a turbocharger, the method comprising:

providing a measuring signal, which is a microwave measuring signal, which is directed at a compressor impeller of the compressor, so that the measuring signal is reflected on revolving blades of the compressor impeller;

detecting the measuring signal reflected by at least one of the revolving blades; and

determining information about the rotational speed as a function of the reflected measuring signal.

2. The method of claim 1, wherein a modulation of the reflected measuring signal is evaluated to determine the information about the rotational speed.

3. The method of claim 2, wherein information about the transmitted measuring signal and information about the reflected measuring signal are multiplied to obtain a product signal including a sum signal and a differential signal, wherein the differential signal is filtered out, and wherein the rotational speed is ascertained from the differential signal, taking into account the number of the blades.

4. The method of claim 3, wherein the product signal is analyzed with the aid of a Fourier analysis to determine the frequency of the differential signal as the information about the rotational speed.

5. The method of claim 1, wherein error information is provided when the rotational speed of the compressor impeller exceeds a rotational speed threshold value.

6. The method of claim 1, wherein a threshold value comparison is performed using the evaluation information, and wherein error information is at least one of stored and output as a function of a result of the threshold value comparison.

7. The method of claim 1, wherein a change in frequency of the reflected measuring signal, occurring because of a Doppler effect due to movement of one of the blades, is evaluated with respect to the transmitted measuring signal to determine the information about the rotational speed.

8. The method of claim 1, wherein a change in position of the compressor impeller is ascertained from a phase offset between the transmitted measuring signal and the reflected measuring signal, wherein the information about the rotational speed is ascertained by evaluating the change in position within a predetermined period of time.

9. The method of claim 1, wherein:

the measuring signal is transmitted to a first compressor impeller of a first compressor, so that the measuring signal is reflected on revolving blades of the first compressor impeller,

the measuring signal is sent to a second compressor impeller of a second compressor, so that the measuring signal is reflected on revolving blades of the second compressor impeller,

the measuring signal reflected by at least one blade of the first compressor impeller is detected in a first time window, and the measuring signal reflected by at least one blade of the second compressor impeller is detected in a second time window, and

the information about the speed of the first compressor impeller and the speed of the second compressor impeller is determined as a function of the particular reflected measuring signals.

10. The method of claim 9, wherein the measuring signal is alternately directed at the first compressor impeller in the first time window and at the second compressor impeller in the second time window.

11. The method of claim 9, wherein the first time window and the second time window are selected in alternation, and wherein the durations of the first time window and the second time window are selected as a function of a particular set compressor capacity of the first compressor and the second compressor.

12. A device for determining information about a rotational speed of a compressor, which is a turbocharger, comprising:

a signal source for supplying a measuring signal, which is a microwave measuring signal, which is directed at a compressor impeller of the compressor, so that the measuring signal is reflected on revolving blades of the compressor impeller;

a sensor element for detecting the measuring signal reflected by at least one blade; and

a control unit for determining the information about the rotational speed as a function of the reflected measuring signal.

13. The device of claim 12, comprising:

at least one antenna for transmitting the measuring signal to a first compressor impeller of a first compressor, so that the measuring signal is reflected on revolving blades of the first compressor impeller, and for transmitting the measuring signal to a second compressor impeller of a second compressor, so that the measuring signal is reflected on revolving blades of the second compressor impeller;

wherein the sensor element is configured to detect in a first time window the measuring signal reflected by at least one blade of the first compressor impeller and to detect in a second time window the measuring signal reflected by at least one blade of the second compressor impeller, and

the control unit is configured to determine the information about the rotational speeds of the first compressor impeller and the second compressor impeller as a function of the particular reflected measuring signals.

14. The device of claim 13, wherein the antenna includes an array antenna, which is triggered by the signal source, so that the measuring signal is alternately directed to the first compressor impeller in the first time window and to the second compressor impeller in the second time window.

15. The device of claim 13, wherein the control unit is configured to alternately select the first time window and the second time window, and wherein the duration of the first time window and the second time window selected as a function of a particular set compressor capacity of the first and second compressors.

16. The device of claim 12, wherein the signal source and the sensor element are situated with respect to an intake manifold for the compressor for injecting the microwave measuring signal into the intake manifold and for receiving the reflected microwave measuring signal by the sensor element, and wherein the microwave measuring signal is at least one of reflected at least once on one of the intake manifold and penetrating once through a wall of the intake manifold.

17. The device of claim 16, wherein the intake manifold is made of an electrically conductive material or reflective sites are provided on the wall of the intake manifold, and is formed by applying an electrically conductive layer to the nonconductive intake manifold.

18. A computer readable medium having a computer program, which is executable by a processor, comprising:

a program code arrangement having program code for determining information about a rotational speed of a compressor, which is a turbocharger, by performing the following;

providing a measuring signal, which is a microwave measuring signal, which is directed at a compressor impeller of the compressor, so that the measuring signal is reflected on revolving blades of the compressor impeller;

detecting the measuring signal reflected by at least one of the revolving blades; and

determining information about the rotational speed as a function of the reflected measuring signal.