REALTIME-CAPABLE RAINFLOW COUNTING METHOD

Abstract

A method for determining load cycles uses a first buffer containing a first value of a physical variable in a first position and a second value thereof in a second position. A measured third value is stored in a third position. A Rainflow filter is applied, it is checked whether a point of inflection results between the first value and the third value. If the second value forms a point of inflection, then the first position is overwritten with the second value, the second position is overwritten with the third value, the second value is discretized and stored as the last entry in a second buffer. If a second-from-last entry and third-from-last entry form a load cycle, then these values are registered in a Rainfall matrix and removed from the second buffer, and the second buffer is again checked for a load cycle.

Claims

1-6. (canceled)

7. A computer-implemented method for determining load cycles, wherein a first buffer contains a first value (x.sub.1) of a physical variable in a first position and a second value (x.sub.2) of the physical variable in a second position, and wherein a third value (x.sub.3) of the physical variable is measured and stored in a third position in the first buffer, the method comprising: applying the Rainflow filter to the second value (x.sub.2); overwriting the first position of the first buffer with the second value (x.sub.2); and overwriting the second position of the first buffer with the third value (x.sub.3); discretizing the second value (x.sub.2) to determine a discretized form; storing the discretized form as a last entry (s.sub.4) in a second buffer and, determining whether a second-from-last entry (s.sub.3) and a third-from-last entry (s.sub.2) form a load cycle, with reference to a last entry (s.sub.4), the second-from-last entry (s.sub.3), the third-from-last entry (s.sub.2), and a fourth-from-last entry (s.sub.1) in the second buffer; determining that the second-from-last entry (s.sub.3) and the third-from-last entry (s.sub.2) form a load cycle; registering the second-from-last entry (s.sub.3) and the third-from-last entry (s.sub.2) in a Rainfall matrix; and removing the second-from-last entry (s.sub.3) and the third-from-last entry (s.sub.2) from the second buffer; and re-checking whether the second-from-last entry (s.sub.3) and the third-from-last entry (s.sub.2) of the second buffer form a load cycle.

8. The method according to claim 7, wherein the method is carried out iteratively.

9. The method according to claim 8, further comprising: measuring a value of the physical variable to determine a measured value; and initializing the first position and the second position of the first buffer using the measured value.

10. A computer-implemented method for determining load cycles, wherein a first buffer contains a first value (x.sub.1) of a physical variable in a first position and a second value (x.sub.2) of the physical variable in a second position, and wherein a third value (x.sub.3) of the physical variable is measured and stored in a third position in the first buffer, the method comprising: applying the Rainflow filter to the second value (x.sub.2); determining that the second value (x.sub.2) does not form a point of inflection; and overwriting the second position in the first buffer with the third value (x.sub.3).

11. A computer program product containing executable code that when executed by a computer performs the method of claim 7.

12. A computing device configured to execute the method of claim 7, the computing device comprising at least one interface configured to read in the third value (x.sub.3) of the physical variable.

13. A vehicle comprising: at least one sensor; and a computing device with an interface, the computing device configured to execute the method of claim 7, wherein the sensor is disposed in communication with the computing device via the interface.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0029] A preferred example embodiment of the invention is illustrated in the figure. Specifically, FIG. 1 shows:

[0030] FIG. 1: A flow chart of a method for determining a load cycle, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0031] FIG. 1 makes clear the process steps of a real-time algorithm for rainflow counting. The algorithm comprises a plurality of part-steps 101, 103, 105, 107, 109, 111.

[0032] In a first part-step 101 a measured value x.sub.3 of a physical parameter is introduced as input into the process. The measured value x.sub.3 is stored in the third position in a first buffer.

[0033] In a second part-step 103 a rainflow filter is used on the values contained in the first buffer. During this step it is checked whether a value x.sub.2 stored in a second position of the first buffer is a point of inflection between a value x.sub.1 stored in a first position of the first buffer and the value x.sub.3 stored in the third position in the first buffer. If that is not the case, the value x.sub.2 contained in the second position of the first buffer is overwritten with the value x.sub.3 previously stored in the third position in the first buffer. Thereafter, a new value of the physical variable is measured and stored in the third position in the first buffer.

[0034] If a point of inflection has been recognized in the second position of the first buffer, then the value x.sub.2 stored therein is discretized in a third part step 105.

[0035] In a fourth part-step 107, in its discretized form the value x.sub.2 is added to a second buffer.

[0036] In a fifth part-step 109 the last four entries in the second buffer are checked in relation to a four-point condition. This makes it possible to ascertain whether a second-from-last entry and a third-from-last entry in the second buffer form a load cycle.

[0037] If the second-from-last entry and the third-from-last entry form a load cycle, in the sixth part-step 111 the two entries are registered in a Rainfall matrix and erased from the second buffer. In that case the entries in the second buffer are again checked in relation to a four-point condition. Otherwise, the process of the method springs back from the fifth part-step 109 to the first part-step 101.

INDEXES

[0038] 101 First part-step [0039] 103 Second part-step [0040] 105 Third part-step [0041] 107 Fourth part-step [0042] 109 Fifth part-step [0043] 111 Sixth part-step