Input abnormality detection apparatus and input abnormality detection method

Abstract

To provide an input abnormality detection apparatus and an input abnormality detection method that can detect an abnormality of an input analog signal with a simpler circuit configuration.SOLUTION: An input abnormality detection apparatus comprises: a voltage converter which outputs an analog output signal generated by converting a voltage of an analog input signal which is input; an analog voltage abnormality detector which detects an abnormality by comparing the analog input signal and the analog output signal; and a processor including an analog / digital converter, to which the analog output signal is input, and a signal input device to which a detection result of the analog voltage abnormality detector is input.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an input abnormality detection device and an input abnormality detection method. [Background technology]

[0002] In a device equipped with a processor, an input analog signal is converted to a digital signal (analog / digital conversion), and the converted digital signal is input to the processor. In such a device, if an abnormality occurs in the processing circuit for the input analog signal, it may cause a malfunction in the processor or the equipment controlled by the processor.

[0003] For example, a motor drive device that drives a motor receives a command value for driving the motor as an analog signal (such as a voltage value). If an abnormality occurs in the processing circuit for the input analog signal, a malfunction such as an excessive current command value flowing through the motor may occur, which may cause the motor to overheat or break down.

[0004] Therefore, input abnormality detection devices are used to detect abnormalities in input analog signals. For example, the redundancy device described in Patent Document 1 detects abnormalities in analog signal processing circuits by monitoring the output of an analog / digital converter using a master CPU and a slave CPU. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-202167 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the redundant device described in Patent Document 1 requires a master CPU and a slave CPU, resulting in a large number of components. There is a demand for an input abnormality detection device that can detect abnormalities in input analog signals with a simpler circuit configuration.

[0007] In view of the above circumstances, an object of the present invention is to provide an input abnormality detection device and an input abnormality detection method that can detect an abnormality in an input analog signal with a simpler circuit configuration. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. An input abnormality detection device according to a first aspect of the present invention comprises a processor having: a voltage converter that outputs an analog output signal obtained by voltage-converting an input analog input signal; an analog voltage abnormality detector that compares the analog input signal with the analog output signal to detect an abnormality; an analog-to-digital converter to which the analog output signal is input; and a signal input device to which the detection result of the analog voltage abnormality detector is input.

[0009] An input abnormality detection method according to a second aspect of the present invention includes generating an analog output signal by voltage-converting an analog input signal, detecting an abnormality by comparing the analog input signal with the analog output signal, and generating a digital signal by analog-to-digital conversion of the analog output signal; If no abnormality is detected, it is assumed that there is no abnormality in the digital signal. [Effects of the Invention]

[0010] According to the input abnormality detection device and input abnormality detection method of the present invention, an abnormality in an input analog signal can be detected with a simpler circuit configuration. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram of an input abnormality detection device according to an embodiment; [Figure 2] FIG. 10 is a block diagram of a modified example of the input abnormality detection device. [Figure 3] 3 is a control flowchart of the input abnormality detection device. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a block diagram of an input abnormality detection device 100 according to this embodiment.

[0013] The input abnormality detection device 100 is a device capable of detecting an abnormality in an analog signal input to a processor 30. The input abnormality detection device 100 includes a voltage converter 10, an analog voltage abnormality detector 20, and a processor 30.

[0014] The voltage converter 10 performs voltage conversion (level shift) on the input analog input signal S1. The voltage converter 10 converts the voltage of the analog input signal S1 and outputs an analog output signal S2 within a voltage range that can be input to the processor 30. The analog output signal S2 is input to the processor 30.

[0015] The analog voltage abnormality detector 20 detects an abnormality in the voltage converter 10 by comparing the analog input signal S1 with the analog output signal S2. Specifically, the analog voltage abnormality detector 20 compares the voltage value V1 of the analog input signal S1 with the voltage value V2 of the analog output signal S2. The analog voltage abnormality detector 20 compares the voltage value V2 with a theoretical voltage value αV1 (α is a conversion coefficient) after voltage conversion of the analog input signal S1, and determines that the voltage converter 10 is normal if the difference is within a predetermined range R. The analog voltage abnormality detector 20 determines that the voltage converter 10 is abnormal if the difference is outside the predetermined range R. Here, the predetermined range R is set to a range within which an error is tolerable (for example, zero ± error).

[0016] The analog voltage abnormality detector 20 outputs the abnormality detection result as a digital signal D. The digital signal D output by the analog voltage abnormality detector 20 is, for example, a 1-bit signal (1: abnormal, 0: normal). The digital signal D is input to the processor 30.

[0017] The processor 30 is a general-purpose processor capable of executing programs, and includes an analog / digital converter 31 and a signal input unit 32.

[0018] The analog / digital converter 31 converts the input analog output signal S2 into a digital signal based on set parameters. The analog / digital converter 31 is built into the processor 30. The processor 30 can acquire the digital signal output by the analog / digital converter 31.

[0019] The signal input device 32 is a general-purpose input terminal (general-purpose input / output terminal) to which a digital signal is input. The processor 30 can acquire the digital signal D input to the signal input device 32.

[0020] When the digital signal D input to the signal input device 32 has a value indicating an abnormality, the processor 30 can recognize that an abnormality has occurred in the voltage converter 10.

[0021] 2 is a block diagram of an input abnormality detection device 100B, which is a modified example of the input abnormality detection device 100. The processor 30B of the input abnormality detection device 100B does not include an analog-to-digital converter 31. In this case, the analog-to-digital converter 31 is provided separately outside the processor 30B.

[0022] Next, a description will be given of the operation (input abnormality detection method) of the input abnormality detection device 100. Hereinafter, the description will be made along with the control flowchart of the input abnormality detection device 100 shown in FIG.

[0023] In step S110, the analog voltage abnormality detector 20 acquires the voltage value V1 of the analog input signal S1 and the voltage value V2 of the analog output signal S2. The analog voltage abnormality detector 20 then executes step S120.

[0024] In step S120, the analog voltage abnormality detector 20 compares the theoretical voltage value αV1 (α is a conversion coefficient) after voltage conversion of the analog input signal S1 with the voltage value V2 of the analog output signal S2 to determine whether the difference is within a predetermined range R. If the difference is within the predetermined range R, the analog voltage abnormality detector 20 then executes step S130. If the difference is outside the predetermined range R, the analog voltage abnormality detector 20 then executes step S140.

[0025] In step S130, the analog voltage abnormality detector 20 outputs a digital signal D indicating a value indicating normality. The analog voltage abnormality detector 20 then executes step S150.

[0026] In step S140, the analog voltage abnormality detector 20 outputs a digital signal D indicating a value indicating an abnormality. The analog voltage abnormality detector 20 then executes step S150.

[0027] The processor 30 receives the digital signal D indicating the value indicating the abnormality and recognizes that an abnormality has occurred in the voltage converter 10, and performs error processing or the like.

[0028] In step S150, the analog voltage anomaly detector 20 determines whether to end the anomaly detection. If the anomaly detection is not to be ended, the analog voltage anomaly detector 20 executes step S110 again. If the anomaly detection is to be ended, the analog voltage anomaly detector 20 next executes step S160 and ends the control flow shown in FIG.

[0029] According to the input abnormality detection device 100 of this embodiment, a status monitoring circuit (circuit surrounded by a dotted line in FIG. 1) is provided for a path through which the analog input signal S1 is input to the processor 30 and a path separate from the path, and abnormalities in the voltage of the analog signal input to the processor 30 can be detected with a simple circuit configuration. The input abnormality detection device 100 does not require a master CPU and a slave CPU as shown in Patent Document 1, and can be implemented with only one processor 30, thereby reducing the number of parts. Many recent general-purpose processors have a built-in analog-to-digital converter 31, like the processor 30 of this embodiment. The number of parts can be further reduced by using a processor 30 that has a built-in analog-to-digital converter 31.

[0030] For example, when the input abnormality detection device 100 is used in a motor drive device, even if the voltage converter 10 fails, it is possible to avoid a situation in which, for example, a maximum command continues to be input, causing the motor to fail.

[0031] Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above embodiment and modifications can be configured by appropriately combining them. [Industrial Applicability]

[0032] The present invention can be applied to a processor to which an analog input signal is input. [Explanation of symbols]

[0033] 100,100B Input abnormality detection device 10 Voltage converter 20 Analog voltage abnormality detector 30,30B processor 31 Digital Converter 32 Signal input device D Digital signal S1 Analog input signal S2 Analog output signal

Claims

1. a voltage converter that converts an input analog input signal into a voltage and outputs an analog output signal; an analog voltage abnormality detector that compares the analog input signal with the analog output signal to detect an abnormality; a processor having an analog / digital converter to which the analog output signal is input, and a signal input device to which the detection result of the analog voltage abnormality detector is input; Equipped with Input anomaly detection device.

2. the detection result input to the signal input device is a digital signal, the signal input device is a general-purpose input terminal of the processor; The input abnormality detection device according to claim 1 .

3. the analog voltage abnormality detector detects the abnormality based on a difference between a voltage value of the analog input signal and a voltage value of the analog output signal; 3. The input abnormality detection device according to claim 1.

4. Generate an analog output signal by converting the analog input signal into a voltage, comparing the analog input signal with the analog output signal to detect an abnormality; generating a digital signal by analog-to-digital converting the analog output signal; When the abnormality is not detected, it is determined that there is no abnormality in the digital signal. Input anomaly detection method.

5. detecting the abnormality based on a difference between a voltage value of the analog input signal and a voltage value of the analog output signal; The input abnormality detection method according to claim 4 .

Images