Input/Output Assembly and Method for Increasing Fail Safe Operation of an Industrial Input/Output Assembly

Abstract

A method for increasing fail-safe operation of an industrial input/output assembly, wherein an external mechanical load that acts on the input/output assembly is determined via an acceleration sensor, where a check is performed to determine whether the load exceeds a predeterminable limit value and, if this is the case, a value of a load sum is then accordingly increased corresponding to an extent to which the value is exceeded, where the load sum is continuously compared to a maximum load value that characterizes a service life of the input/output assembly, and a maintenance message is output when the maximum load value is reached.

Claims

1. A method for increasing fail-safe operation of an industrial input/output assembly, the method comprising: determining an external mechanical load that acts on the input/output assembly via an acceleration sensor; performing a check to determine whether the load exceeds a predeterminable limit value and increasing a value of a load sum corresponding to an extent to which the value is exceeded if the load exceeds the predeterminable limit value; comparing the load sum continuously to a maximum load value which characterizes a service life of the input/output assembly and outputting a maintenance message when the maximum load value is reached.

2. The method as claimed in claim 1, wherein a time continuous signal curve is recorded using the acceleration sensor and the load sum is calculated aided by an integration.

3. The method as claimed in claim 1, wherein the measured values for the mechanical load are statistically evaluated.

4. The method as claimed in claim 2, wherein the measured values for the mechanical load are statistically evaluated.

5. The method as claimed in claim 1, wherein a mass of the input/output assembly is taken into consideration during calculation of the load sum.

6. The method as claimed in claim 1, wherein a temperature of the input/output assembly is taken into consideration during calculation of the load sum.

7. The method as claimed in claim 1, wherein the maximum load value is determined by experimental vibration and shock testing.

8. The method as claimed in claim 1, wherein an actual failure limit is determined by experimental vibration and shock testing and a value for an actual failure limit is utilized in the input/output assembly for output of an alarm notification.

9. An input/output assembly comprising: an acceleration sensor; a measuring device configured to measure an external mechanical load via the acceleration sensor; a checking device configured to check whether the load has exceeded a predeterminable limit value; a load sum counter configured to add to a load sum an extent to which the predeterminable limit is exceeded; a monitoring device configured to continuously compare the load sum to a maximum load value which characterizes a service life of the input/output assembly, and configured to output a maintenance message when the maximum load value is reached.

10. The input/output assembly as claimed in claim 9, further comprising: a recording device which is connected to the acceleration sensor and which records a time continuous signal curve; and an integration device configured to calculate the load sum aided by an integration via the signal curve.

11. The input/output assembly as claimed in claim 9, further comprising: a processing module which converts time continuous values via an analog-digital converter and which performs a vibration analysis after a transformation in a frequency range and which statistically evaluates measured values for the mechanical load (B).

12. The input/output assembly as claimed in claim 10, further comprising: a processing module which converts time continuous values via an analog-digital converter and which performs a vibration analysis after a transformation in a frequency range and which statistically evaluates measured values for the mechanical load.

13. The input/output assembly as claimed in claim 9, further comprising: a parameterizable memory; wherein the mass of the input/output assembly is input into said parameterizable memory, the mass being retrievable from said parameterizable memory for calculation of the load sum.

14. The input/output assembly as claimed in claim 10, further comprising: a parameterizable memory; wherein the mass of the input/output assembly is input into said parameterizable memory, the mass being retrievable from said parameterizable memory for calculation of the load sum.

15. The input/output assembly as claimed in claim 11, further comprising: a parameterizable memory; wherein the mass of the input/output assembly is input into said parameterizable memory, the mass being retrievable from said parameterizable memory for calculation of the load sum.

16. The input/output assembly as claimed in claim 9, further comprising: a temperature sensor; wherein a temperature of the input/output assembly is retrievable for calculation of the load sum.

17. The input/output assembly as claimed in claim 9, further comprising: further parameterizable memories in which a maximum load value which is determined in an experimental manner or an actual failure limit is input into said further parameterizable memories.

18. The input/output assembly of claim 9, wherein the acceleration sensor comprises a MEMS sensor.

19. The input/output assembly of claim 9, further comprising: a fieldbus interface; and a transmitting device; wherein all measured values and maintenance messages are transmittable via the transmitting device via the fieldbus interface to a fieldbus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] An exemplary embodiment of a telescopic strut in accordance with the invention will be explained hereunder by way of the drawings, in which:

[0027] FIG. 1 shows an exemplary embodiment of an input/output assembly in accordance with the invention; and

[0028] FIG. 2 is a flowchart of the method in accordance with the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0029] With reference to FIG. 1, illustrated therein is an input/output assembly 1 comprising an acceleration sensor BS, a measuring device ME and a checking device PM. The measuring device ME receives measured values from the acceleration sensor BS and checks the measured values for whether these values exceed a predeterminable limit value GW. For each occasion the predeterminable limit value GW is exceeded, an extent H by which the limit value is exceeded is summed in the load sum counter BSZ. In order to monitor these summed loads, in turn a monitoring device UM is provided that is configured to continuously compare the load sum BSS to a maximum load value B.sub.Max that characterizes a service life L of the input/output assembly 1 and for the case that the maximum load value B.sub.Max is reached, a maintenance message WM is output.

[0030] Furthermore, the input/output assembly 1 has a recording device AM that is connected to the acceleration sensor BS and records a continuous signal curve S(t), where an integration device IM is provided that is configured to calculate the load sum BSS′ with the aid of an integration via the signal curve S(t).

[0031] A processing module VM is configured to convert time continuous values via an analog-digital converter and to perform a vibration analysis after a transformation in the frequency range, such as the Fast Fourier transformation, and to statistically evaluate the measured values for the mechanical load B.

[0032] With regard to a yet more precise statement regarding a possible future point in time of failure, the input/output assembly 1 has parameterizable memories 2,3,4. A mass m of the input/output assembly 1 can be stored in a first memory 2. A maximum load value E.sub.Max that is determined in an experimental manner can be stored in a second memory 3 or can be externally parameterized. A failure limit Ex can be parameterized in a third memory 4.

[0033] The stored values such as mass m, load value E.sub.Max that is determined in an experimental manner and failure limit Ex can be included in the calculation regarding a future point in time of failure.

[0034] In addition thereto, a temperature sensor TS provides the temperature T prevailing at the time in the input/output assembly 1. If, in addition to a mechanical load B, the temperature T of the assembly is also still particularly high, a mechanical aging that is caused by a mechanical load B thus increases yet further and the assembly could fail more rapidly.

[0035] In order to be able to also relay the detected measured values to a superordinate automation system, the input/output assembly 1 has a fieldbus interface 5 and a transmitting device 6, where all the measured values and maintenance messages WM can be transmitted via the transmitting device 6 via the fieldbus interface 5 to a fieldbus 7.

[0036] The mechanical loads B that act on the input/output assembly 1 are typically provided in an x,y,z coordinate system on three axes. For receiving decentralized process values, the assembly has a first input E1 up to a fifth input E5. For the output of actuator values for the industrial process, the assembly has a first output A1 up to a fifth output A5.

[0037] FIG. 2 is a flowchart of the method for increasing fail-safe operation of an industrial input/output assembly 1. The method comprises determining an external mechanical load B that acts on the input/output assembly 1 via an acceleration sensor BS, as indicated in step 210.

[0038] Next, a check is performed to determine whether the load B exceeds a predeterminable limit value GW and increasing a value of a load sum BSS is increased corresponding to an extent H to which the value is exceeded if the load B exceeds the predeterminable limit value GW, as indicated in step 220.

[0039] Next, the load sum BSS is continuously compared to a maximum load value B.sub.Max which characterizes a service life L of the input/output assembly 1, as indicated in step 230. In accordance with the invention, a maintenance message WM is output when the maximum load value B.sub.Max is reached.

[0040] Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods described and the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.