JPS62126444A - Failure diagnosing system - Google Patents

Abstract

PURPOSE:To check and evaluate the operation, processing, etc., of a failure diagnosing means by outputting a failure signal intensionally under an optional condition even during the operation of an object to be diagnosed. CONSTITUTION:When a switching signal is inputted under control by an external hardware or a microprogram, a switching circuit 5 is driven and an output signal from a simulative failure generating circuit 4 is inputted to a failure diagnosing circuit 1 in stead of the output of the object 2 to be diagnosed to diagnose the intentionally generated failure signal in the failure diagnosing circuit 1. Namely, an output signal 3 deciding the generation of a failure as the result of diagnosis is outputted, that the operation or processing of a failure diagnosing circuit 1 is normal can be decided. In such a case, a simulative failure generating circuit 4 capable of the simulation of various failures is prepared in addition to he factors of all failures to be generated in the object 2 to be diagnosed and respective failure signals are selected and inputted to he circuit 1, so that the normality or abnormality of the failure of the circuit 1 to respective failure signals can be highly accurately decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fault diagnosis system for diagnosing a fault diagnosis target.

[Conventional technology]

FIG. 2 is a block connection diagram of a conventional fault diagnosis system. In the figure, 1 is a fault diagnosis circuit as a fault diagnosis means, 2 is a fault diagnosis target to be diagnosed by this fault diagnosis means 1, and this is a software Or it is configured as hardware. Further, the above-mentioned failure diagnosis target is configured as a digital control circuit of various control machines, for example, and is installed and used in any digital control device.

Next, the operation will be explained.

In the above fault diagnosis system, the fault diagnosis circuit 1 constantly monitors the fault diagnosis target 2 and outputs a normal output when it is normal and a fault output when it is in failure. The failure diagnosis target 2 configured as a digital control device is normally normal during control operation, and the failure diagnosis circuit 1 monitoring it outputs a normal output.

[Problem that the invention seeks to solve]

Since the conventional failure diagnosis system is configured as described above, when a failure occurs in the software or hardware of the failure diagnosis target 1 during the control operation of the failure diagnosis target 1, the failure diagnosis circuit 2 is normally operated. When confirming whether or not the control is operating properly, it is necessary to cause failures to occur frequently in the failure diagnosis target 2 during the test stage, but under any conditions during the above control operation.

It is extremely difficult to create a failure situation at an arbitrary timing, and there are problems in that it is not always possible to accurately evaluate the operation of the failure diagnosis circuit 2 by checking its operation with high accuracy.

This invention was made in order to solve the above-mentioned problems, and is designed to intentionally output a fault signal under arbitrary conditions even during the operation of the fault diagnosis target, thereby controlling the operation and processing of the fault diagnosis means. The purpose is to obtain a failure diagnosis system that can confirm and evaluate the following.

[Means for solving problems]

The fault diagnosis system according to the present invention is configured such that the output of the pseudo fault generation circuit can be input to the fault diagnosis means in place of the output of the fault diagnosis target using the switching circuit.

[Operation] The switching circuit according to the present invention operates to select each output of the fault diagnosis target or the pseudo-fault generating circuit according to a switching signal inputted from the outside and inputting the selected output to the fault diagnosing means. By intentionally outputting a fault signal under arbitrary conditions and inputting this fault signal to the fault diagnosing means through the switching circuit, it is possible to check whether or not this fault diagnosing means is operating normally. Or make it possible to evaluate.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 1, 1 is a fault diagnosis circuit as a fault diagnosis means, 2 is a fault diagnosis target to be diagnosed by the fault diagnosis circuit 1, and 3 is the fault diagnosis described above. The output of the circuit 1, 4 is a pseudo-fault generating circuit that intentionally outputs a fault signal, 5 is a switching circuit, and 6 is a switching signal of the switching circuit 5 set from the outside.

Next, the operation will be explained. First, until a switching signal from the outside is input to the switching circuit 5, the fault diagnosis circuit 1 constantly monitors the fault diagnosis target 2, as in the case of the prior art.

Here, when a switching signal is input under the control of external hardware or a microprogram, the switching circuit 5 operates and replaces the output signal of the pseudo fault generation circuit 5 with the output of the fault diagnosis target to the fault diagnosis circuit 5. A fault signal generated intentionally is diagnosed in the fault diagnosis circuit 1. That is, if the diagnosis result is the output signal 3 indicating a failure, it can be determined that the operation and processing of the failure diagnosis circuit 1 are normal.

In this case, a simulated fault generation circuit 4 capable of simulating various faults is prepared according to a limited number of possible fault causes of the fault diagnosis target 2, and each of these fault signals is selected and input to the fault diagnosis circuit 1. By doing so, it is possible to determine with high precision whether the response of the failure diagnosis circuit 1 to each failure signal is normal or abnormal.

〔Effect of the invention〕

As described above, according to the present invention, the switching circuit is configured to input the output of the pseudo-fault generating circuit to the fault diagnosing means instead of the output of the fault diagnosis target, so that the fault diagnosis target does not perform the original control operation. The present invention has the advantage that even when executing the fault diagnosis circuit, the operating state and processing state of the fault diagnosis circuit can be easily and accurately confirmed or evaluated using the fault signal from the pseudo fault generating circuit.

[Brief explanation of drawings]

FIG. 1 is a block connection diagram of a fault diagnosis system according to an embodiment of the present invention, and FIG. 2 is a block connection diagram of a conventional fault diagnosis system. 1 is a fault diagnosis means, 2 is a fault diagnosis target, 4 is a pseudo fault generation circuit, and 5 is a switching circuit. In addition, in the figures, the same reference numerals indicate the same or similar parts.

Claims (1)

[Claims] In a fault diagnosis system in which a fault diagnosis target is constantly monitored by a fault diagnosis means, the fault diagnosis means includes a pseudo fault generation circuit that generates a pseudo fault signal and an output of the pseudo fault generation circuit in place of the output of the fault diagnosis target. A fault diagnosis system characterized by comprising a switching circuit that selectively inputs input to the system.