JP6625640B2 - Pressure measuring device and clutch actuator device including hydraulic section - Google Patents

Description

  The present invention relates to a pressure measuring device comprising a pressure sensor and sensor electronics, the sensor electronics having a first measurement channel (Messkanal) for pressure measurement. Further, the present invention relates to a clutch actuator device.

  German Patent Application DE 102 01 1014931 A1 discloses a method for controlling an automated clutch. The clutch is operated via a hydraulic clutch operating system having a hydrostatic actuator. The pressure of the hydrostatic actuator is detected by a pressure sensor so that the state of the hydraulic clutch operation system can be accurately grasped.

  In the case of such an actuator with a hydraulic section, very accurate measurement results need to be provided within the individual sections of the measurement range of the pressure sensor. This is because the state of the clutch actuator or the clutch is estimated within these individual measuring ranges.

  As can be seen in FIGS. 4 and 5, a pressure measuring device comprising a pressure sensor with a measuring bridge and sensor electronics with two measuring channels is known. The analog / digital converter, which is a component of the measurement channel, is adjusted so that both cover the entire measurement range of the pressure measuring device (FIG. 4). The measuring bridge has an intermediate tap, at which point the analog / digital converter extracts the bridge voltage. In order to increase the safety integrity level, as shown in FIG. 5, redundancy is required, for which two measurement channels leading to two analog / digital converters of the sensor electronics are used, both of which are used. The measuring channels each have a resolution over the entire measuring range of the pressure measuring device.

  DE-A 10 2007 008 977 discloses a method for opening and / or closing an automated clutch in which the clutch moment of the clutch is increased in order to increase the accuracy of the control. Two different parameters are observed in each different range. The operating member that operates the clutch includes a clutch moment in a first range of clutch moment that is related to the position of the operating member and a clutch torque that is related to a force applied to the clutch by the operating member in a second range of clutch moment. Operated according to the characteristic line indicating the moment. This requires a high computing power in signal evaluation.

  The problem underlying the present invention is to provide a pressure measuring device with improved measurement accuracy, despite the fact that the signal evaluation is performed in a time-saving manner.

  According to the invention, the object is achieved in that the measuring electronics has a second measuring channel for pressure measurement, the first measuring channel has a first measuring range, and the second measuring channel has a second measuring channel. The first and second measurement ranges each have at least a portion of the entire measurement range. By dividing the entire measurement range into partial measurement ranges of both measurement channels, it is achieved that each measurement range exhibits high measurement accuracy. Within this measurement range, a predetermined pressure signal is expected. The measuring range is therefore adjusted to correspond to the desired pressure value of the pressure sensor used.

  Advantageously, the first measurement channel covers the whole measurement range and the second measurement channel covers the lower part of the whole measurement range. In this way, the validity of the pressure signals detected by the two measuring channels is easily checked with one another. This is because a specific pressure value is expected for each measurement range. If the expected pressure value does not occur, the error of the pressure measuring device can be estimated.

  Alternatively, the first measurement channel spans the upper part of the entire measurement range and the second measurement channel spans the lower part of the entire measurement range. In this embodiment, when presenting a specific pressure signal, a signal is output from only one of the measurement channels. This is because the other measuring range cannot detect this pressure signal. This configuration is particularly important when the pressure signal at the end of the entire measuring range of the pressure measuring device is particularly important. In this case, the part of the whole measurement range between the upper part and the lower part of the whole measurement range does not need to be observed in detail. This is because the pressure signal is not evaluated in this region.

  In one aspect, the first measurement channel has a first analog-to-digital converter that defines a first measurement range, and the second measurement channel has a second analog-to-digital converter that defines a second measurement range. And a first analog / digital converter and a second analog / digital converter are connected to a digital signal processor of the sensor electronics. The use of two analog / digital converters with different resolutions makes it possible to form a pressure measuring device which makes it possible to measure the pressure and simultaneously validate both output signals of the measuring channel simultaneously with the hardware. Is done.

  In a variant, one measuring bridge of the pressure sensor is connected to both analog / digital converters of the sensor electronics. In this case, both analog / digital converters evaluate the bridge voltage of the analog / digital converter output from the measuring bridge. This allows a particularly simple validation.

  Alternatively, the pressure sensor has two measurement bridges, each of which is connected to a respective analog / digital converter. The use of two measurement bridges allows an estimation of the behavior of the entire pressure measuring device. At this time, the validity check section also includes the measurement bridge. In this way, errors of the measuring bridge can also be detected by means of this evaluability.

  In one embodiment, the output signals of the sensor electronics are provided to a validation device for validating the signals output from both analog / digital converters. Since the plausibility check device is located outside the measuring bridge and the sensor electronics, this makes it possible to estimate the behavior of the entire pressure measuring device and possibly recognize errors.

  One aspect of the present invention relates to a clutch actuator device including a hydraulic section and a pressure measuring device that detects a predetermined state of an actuator and / or a clutch. In order to obtain a particularly accurate measuring signal in the clutch actuator device, the pressure measuring device is designed in accordance with at least one feature of the claims.

  Another aspect of the present invention is a method for checking the validity of an output signal output from a pressure measuring device, the method comprising: Comparing each output signal with a predetermined output signal and estimating an error of the pressure measurement device when at least one output signal output from the pressure measurement device indicates a deviation from the predetermined output signal; It relates to the validation method. This enables particularly simple and low-cost error monitoring of the pressure measuring device.

  In one form, each measurement channel is connected to a respective measurement bridge, and estimates an error of one of the measurement bridges when an output signal output from the pressure measuring device indicates a deviation from a predetermined output signal. . By using one measurement bridge per measurement channel, a plurality of measurement bridges are simultaneously monitored. Therefore, the displacement of the measurement bridge can be detected with high reliability.

  The present invention allows for a number of embodiments. Two of the embodiments will be described in detail with reference to the drawings shown in the drawings.

It is a figure showing the schematic structure of a hydraulic clutch system. FIG. 3 is a diagram showing a first embodiment of the pressure measuring device according to the present invention. FIG. 4 is a view showing a second embodiment of the pressure measuring device according to the present invention. FIG. 2 is a diagram showing an example of a pressure measuring device according to a conventional technique. FIG. 6 is a diagram showing a second embodiment of the pressure measuring device according to the prior art.

  FIG. 1 schematically shows the structure of a hydraulic clutch system 1 using a hydrostatic clutch actuator as an example. This schematic diagram shows only the structure that operates one of the two dual clutches of the dual clutch transmission system. The operation of the second clutch of the dual clutch transmission system is performed in a similar manner and will not be described further herein.

  The hydrostatic clutch system has a control device 2 for controlling the clutch actuator 3. When the position of the clutch actuator 3 changes, the piston 4 of the master cylinder 5 is moved rightward along the actuator stroke, whereby the volume in the master cylinder 5 changes, and the pressure p is set in the master cylinder 5. It is formed. This pressure p is transmitted to the slave cylinder 8 via a hydraulic line 7 by a hydraulic working fluid 6 used as a pressure medium, and the slave cylinder 8 operates a clutch 9 via a preload spring 12. At this time, the pressure p of the hydraulic working fluid 6 causes a change in stroke in the slave cylinder 8. This stroke change appears as an operation of the clutch 9. The pressure p is determined by the pressure measuring device 10 in the master cylinder 5. The pressure measuring device 10 is connected to the control device 2. The travel distance traveled by the clutch actuator 3 along the actuator travel is specified by the travel sensor 11. Hereinafter, the stroke in which the clutch actuator 3 has moved is considered to be the same as the stroke of the clutch 9.

  FIG. 2 shows a first embodiment of the pressure measuring device 10. The pressure measuring device 10 comprises a measuring bridge 13, preferably a Wheatstone resistance bridge, which is arranged on a strain-sensitive carrier element 14. This carrier element 14 can be made of steel or ceramics and has a waist. This measuring bridge 13 is connected on the one hand to the supply voltage Vss and on the other hand to the ground GND. The intermediate taps 15 and 16 of the measuring bridge 13 lead to sensor electronics 17. The sensor electronics 17 has measurement channels 20, 21 each having one analog / digital converter 18, 19, which are connected to a digital signal processor 22. The signal processor 22 outputs an output signal 23 to the control device 2.

  In this example, it is desirable that the state of the clutch actuator 3 or the clutch 9 be estimated from the individual measurement ranges of the pressure measurement device 10. For example, a pressure sensor reading of less than 5 bar is used to detect a reliable release of the clutch 9. Assuming that the entire measuring range of the pressure measuring device 10 is 50 bar, this pressure range corresponds to the lower part of the entire measuring range. In another form, similarly high-precision pressure signals have to be detected in the upper part of the entire measuring range, for example around 48 bar. This is because this pressure signal provides reliable information as to whether the clutch actuator 3 is still protected.

  The analog / digital converters 18, 19 have different resolutions for this purpose. The analog / digital converter 18 has a resolution over the entire measuring range of the pressure measuring device 10 of 50 bar. The second analog / digital converter 19 has a resolution of 0 to 5 bar, which corresponds to the lower part of the whole measuring range. When the pressure is higher than 5 bar, the second analog / digital converter 19 transitions to the locked state (Klemmzstand). This basically means that a signal corresponding to a pressure of 5 bar is output.

  The measurement bridge 13 outputs a bridge voltage at the intermediate taps 16 and 17. The bridge voltage depends on how much the individual resistances of the measuring bridge 13 have expanded and contracted. The bridge voltage is detected by both analog / digital converters 18,19. These output signals of the analog / digital converters 18 and 19 are transmitted to the control device 2. The control device 2 is used as a validity checking device and evaluates these pressures.

  When a pressure of less than 5 bar is output from the measuring bridge 13, the same output signal should be output by both analog / digital converters 18, 19 if the function of the sensor electronics 17 is normal. If the same output signal is not output, it is assumed that there is an error in the sensor electronics 17. However, when the measuring bridge 13 outputs a bridge voltage corresponding to a pressure signal of about 48 bar, the control device 2 receives the signal of 48 bar from the analog / digital converter 18 and receives the signal of 48 bar from the analog / digital converter 19. You should receive a 5 bar signal. If the analog / digital converter shows a signal of less than 5 bar, it can be assumed that the analog / digital converter is not normal.

  In the embodiment shown in FIG. 2, the electronic circuits are redundantly configured. The second embodiment shown in FIG. 3 shows a pressure measuring device 10 with two measuring bridges 13 and 24. The intermediate tap of each measurement bridge 13, 24 leads to one of the analog / digital converters 18, 19, respectively. In the case of the sensor electronics 17 as well, the idea of using two different measuring ranges in different analog / digital converters 18 and 19 is inherited. However, with this arrangement, the function of the measuring bridges 13 and 24 can additionally be monitored. Also in the present embodiment, the control device 2 receives one output signal from each of the analog / digital converters 18 and 19 and evaluates the output signal as described above.

  In that case, the pressure measuring device 10 is not limited to a total measuring range of 50 bar and the proposed partial measuring range, but can also be adapted to different pressure values for different applications. A good plausibility check is possible by adjusting the sensor electronics 17 to a special measuring range. Since a good validation is possible, an extremely high ASIL integrity (ASIL-Integritaet) is achieved, which improves the functional safety of the pressure measuring device 10.

DESCRIPTION OF SYMBOLS 1 Clutch system 2 Control device 3 Clutch actuator 4 Piston 5 Master cylinder 6 Hydraulic hydraulic fluid 7 Hydraulic line 8 Slave cylinder 9 Clutch 10 Pressure measuring device 11 Stroke sensor 12 Preload spring 13 Measurement bridge 14 Carrier element 15 Intermediate tap 16 Intermediate tap Reference Signs List 17 sensor electronic circuit 18 analog / digital converter 19 analog / digital converter 20 measurement channel 21 measurement channel 22 signal processor 23 output signal 24 measurement bridge

Claims (9)

A pressure sensor (13, 24) having a sensor electronics (17), said sensor electronics (17) comprising a first measurement channel (20) and a second measurement channel (21) for measuring pressure; A pressure measuring device,
Before SL first measurement channel (20) has a first measuring range across the entire measurement range, the second measurement channel (21) is in the range of less than a certain value of the entire measurement range the Has a measurement range of 2 ,
The pressure measuring device measures the pressure formed in the master cylinder of the hydrostatic clutch actuator, and one of the measuring ranges is used for detecting the reliable release of the clutch. apparatus. A pressure sensor (13, 24) having a sensor electronics (17), said sensor electronics (17) comprising a first measurement channel (20) and a second measurement channel (21) for measuring pressure; A pressure measuring device,
The first measurement channel (20) has a first measurement range at the upper end of the entire measurement range, and the second measurement channel (21) has a second measurement range at the lower end of the whole measurement range. Having a portion between the upper end and the lower end is not a measurement target,
The pressure measuring device measures the pressure formed in the master cylinder of the hydrostatic clutch actuator, and one of the measuring ranges is used for detecting the reliable release of the clutch. apparatus. The first measurement channel (20) has a first analog-to-digital converter (18) that defines the first measurement range, and the second measurement channel (21) includes the second measurement channel (21). A second analog / digital converter (19) for defining a measurement range, wherein the first analog / digital converter (18) and the second analog / digital converter (19) 3. The pressure measuring device according to claim 1, wherein the pressure measuring device is connected to a digital signal processor (22) of the circuit (17). 4. The pressure according to claim 3 , wherein one measuring bridge (13) of the pressure sensor is connected to both analog / digital converters (18, 19) of the sensor electronics (17). measuring device. The pressure sensor has two measurement bridges (13, 24), each of the measurement bridges (13, 24) being connected to one of the analog / digital converters (18, 19). The pressure measuring device according to claim 3 , characterized in that: An output signal of the sensor electronic circuit (17) is supplied to a plausibility check device (2) for plausibility check of the signals output from the analog / digital converters (18, 19). The pressure measuring device according to at least one of claims 3 to 5 , characterized in that: Clutch actuator device comprising a pressure measuring device (10) according to one of the preceding claims ,
The clutch actuator device, wherein the pressure measuring device (10) is configured to detect a predetermined state of the clutch actuator (3) and / or the clutch (9) . A validation method for the output signal outputted from the pressure measuring device of any one of claims 1 to 6 (10), before Symbol pressure measuring device (10) from both the measuring channel (20, 21) comparing the output signal output via the pressure measurement device (10) with the predetermined output signal, respectively, when at least one output signal from the pressure measuring device (10) indicates a deviation from the predetermined output signal. A validity checking method for estimating an error of the pressure measuring device (10). Each measurement channel (20, 21) is connected to one measurement bridge (13, 24), respectively, and an output signal output from the pressure measuring device (10) indicates a deviation from the predetermined output signal. 9. The method according to claim 8 , wherein an error of one of the measuring bridges (13, 24) is estimated.

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