JP2016091483A - Control system and failure diagnosis method for the system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system and a failure diagnosis method for the system, which enable: detection of an abnormal state by an abnormality determination on a central processing device-side even in a case where a selector IC is unable to report an error of itself; and switching to control for protecting equipment such as an engine under control of the control system when the abnormality state is detected, thus making it possible to secure a safe and minimum vehicle operation.SOLUTION: A control system performs: inputting an output from a signal output terminal 21b of a selector IC 21 to inspect time-series data Di of the detection signal for each of sensors 11-18; defining a sensor that has output a test signal determined to be abnormal as an abnormal signal sensor, and defining a sensor that has output a test signal determined to be normal as a normal signal sensor; and determining, in a case where the number Num of the abnormal signal sensors is larger than a number Nα of a pre-set abnormality determination ratio α relative to the number Nst of all sensors connected to the selector IC 21, that the selector IC 21 is abnormal regardless of an output of an error signal terminal 21d.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control system and a control system failure diagnosis method, and more particularly to a control system and a control system failure diagnosis method capable of diagnosing a failure of a selector IC other than the error notification of the selector IC itself.

  In operation control of a vehicle equipped with an internal combustion engine, analog signals and digital signals from a number of sensors such as a speed sensor, an engine water temperature sensor, an atmospheric pressure sensor, etc. are input and operation control is performed using these signals. Yes.

  As shown in FIG. 1, the control system 1 uses a control device (ECM: engine control module) 20 having a central processing unit (CPU) 22, and the signal devices 10 such as various sensors 11 to 18. Is once received by each channel of the AD conversion block, and then the signal divided in time series is output to the signal output terminal 21b through the selector 21a of the control device 20.

  The central processing unit 22 inputs the time series data of the signal from the signal output terminal 21b, and the demultiplexer (distribution circuit) (not shown) converts the time series data of the signals of the various sensors 11-18. The detection values are identified and handled as time series data of the detection values of the various sensors 11 to 18 for various controls.

  The selector IC 21 is provided with an internal diagnostic circuit 21c, which self-diagnose a failure in the selector IC 21 and outputs the result to an error signal terminal 21d. By monitoring the output of 21d, it is determined that the signal from the selector IC 21 is valid, that is, it is not an erroneous signal.

  In this connection, for example, when an analog conversion input terminal and a digital signal processing block digital / analog input terminal are provided, the same input signal is input to the analog / digital input terminal so that an internal abnormality can be detected. The AD conversion block or the digital signal processing block obtained based on the conversion result and the digital signal processing block processing result is used to estimate an abnormality of the AD conversion block or the digital signal processing block. There has been proposed an electronic control device equipped with a microcomputer that presumes that the AD conversion block or the digital signal processing block is abnormal when there is a contradiction between the conversion result of the conversion block and the processing result of the digital signal processing block ( For example, see Patent Document 1).

  However, in the conventional technique, in the failure diagnosis of the selector IC 21 in the control system 1, only the error notification signal output to the error signal terminal 21d is used for error determination, so the internal diagnosis circuit 21c of the selector IC 21 is used. The failure can be determined only when the selector IC 21 makes a self-judgment and notifies it as an error. When the failure occurs such that the selector IC 21 cannot notify its own error, this failure can be detected. There was a problem that I could not.

JP2013-243457A

  The present invention has been made in view of the above, and an object of the present invention is to be in an abnormal state in the abnormality determination on the central processing unit side even if the selector IC falls into a failure that cannot notify its own error. Control system can be switched to control for protection of equipment such as the engine controlled by the control system when this abnormal condition is detected, and safety and minimum vehicle operation can be ensured And providing a fault diagnosis method for a control system.

  In order to achieve the above object, a control system of the present invention includes a selector that receives signals from a plurality of sensors, a signal output terminal that outputs an output signal of the selector, an internal diagnostic circuit, and a diagnosis in the internal diagnostic circuit. In a control system including a selector IC having an error signal terminal for outputting a result and a central processing unit, the central processing unit inputs an output from the signal output terminal of the selector IC and detects each sensor. A time-series data inspection unit that inspects the time-series data of the signal, and an inspection signal sensor determined to be abnormal based on the inspection result of the time-series inspection unit is an abnormal signal sensor, and is determined to be normal. When the sensor of the inspection signal is a normal signal sensor, the number of the abnormal signal sensors is the number of all sensors connected to the selector IC. If greater than the number of abnormality determination proportions set because, regardless of the output of said error signal terminals, and a selector IC abnormality determining means for determining said selector IC is abnormal.

  According to this configuration, even if the selector IC falls into a failure such that it cannot notify its own error, it can be detected as an abnormal state by the abnormality determination on the central processing unit side, and when this abnormal state is detected, It is possible to switch to control for protecting equipment such as an engine controlled by the control system, and to ensure safety and minimum vehicle operation.

  It should be noted that the time series inspection means and the selector IC abnormality determination means preferably operate their functions at all times when the control system is operating, but they are constant in consideration of safety and controllability. The function may be activated at time intervals.

  Further, in the above control system, the time-series inspection unit is configured such that the time-series data of the detection signal of the sensor to be inspected deviates from a range of an upper limit value and a lower limit value set in advance for each sensor to be inspected. Time series data to be inspected with respect to the inspection time and the data width set in advance for each of the sensors to be inspected. However, when the number of data that falls outside the data width within the inspection time is equal to or smaller than the preset second deviation number, it is determined to be abnormal.

  These upper limit value, lower limit value, inspection time, data width, first deviation number, second deviation number, and the like are set according to the characteristics of the target sensor, the degree of influence of the detected value of the sensor in the control, and the like.

  In the above control system, the abnormality determination ratio is set to 60%. This abnormality determination ratio is actually set according to the characteristics of the target sensor, the degree of influence of the detected value of the sensor in the control, and the sensitivity of the device to be controlled. In some cases, 80%, 90%, 100 % (Total number) is set.

  In the above control system, the control system controls a vehicle equipped with an internal combustion engine. In this case, since many sensors are used and it is important to ensure the safety of the crew, the merit of the present invention is further increased.

  And the fault diagnosis method of the control system of the present invention for achieving the above-mentioned object is a selector that receives signals from a plurality of sensors, a signal output terminal that outputs an output signal of the selector, an internal diagnostic circuit, In a fault diagnosis method for a control system comprising a selector IC having an error signal terminal for outputting a diagnosis result in the internal diagnostic circuit and a central processing unit, an output from the signal output terminal of the selector IC is input, The time series data of the detection signal for each sensor is inspected, the sensor of the inspection signal determined to be abnormal is the abnormal signal sensor, the sensor of the inspection signal determined to be normal is the normal signal sensor, and the abnormality When the number of signal sensors is larger than a preset number of abnormality determination ratios relative to the number of all sensors connected to the selector IC, the error signal Regardless of the output of the child, a method characterized by determining said selector IC is abnormal. According to this method, the same effect as that of the above control system can be obtained.

  According to the control system and the control system failure diagnosis method of the present invention, even if the selector IC falls into a failure in which it cannot notify its own error, it can detect an abnormal state by the abnormality determination on the central processing unit side. When this abnormal state is detected, it is possible to switch to control for protection of equipment such as an engine controlled by the control system, and to ensure safety and minimum vehicle operation.

It is a figure which shows the structure of the control system of embodiment which concerns on this invention.

  Hereinafter, a control system and a control system failure diagnosis method according to embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a control system 1 according to an embodiment of the present invention includes a signal device (sensor group) 10 and a control device (ECM: engine control module) 20, and the signal device 10 includes a speed sensor 11, a water temperature. It consists of various sensors such as a sensor (oil temperature sensor?) 12, an engine water temperature sensor 13, a fuel temperature sensor 14, an intake air temperature sensor 15, an exhaust gas temperature sensor 16, an atmospheric pressure sensor 17, and a boost pressure sensor 18. The control device 20 includes a selector IC 21 and a central processing unit (CPU).

  Then, after receiving signals from the signal device 10 such as various sensors 11 to 18 in each channel of the AD conversion block, the signals divided in time series are passed through the selector (multiplexer: selection circuit) 21a of the selector IC 21. The signal is output to the signal output terminal 21b.

  On the other hand, in the central processing unit 22, the time series data of the signal from the signal output terminal 21b is input, and the demultiplexer (distribution circuit) (not shown) converts the time series data of the signals of the various sensors 11-18. The detection values are identified and handled as time series data of the detection values of the various sensors 11 to 18 for various controls.

  The selector IC 21 is provided with an internal diagnostic circuit 21c, which self-diagnose a failure in the selector IC 21 and outputs the result to the error signal terminal 21d.

  In the present invention, a selector 21a that receives signals from the plurality of sensors 11 to 18, a signal output terminal 21b that outputs an output signal of the selector 21a, an internal diagnostic circuit 21c, and a diagnosis in the internal diagnostic circuit 21c. In a control system including a selector IC 21 having an error signal terminal 21d for outputting a result and a central processing unit 22, the central processing unit 22 includes a time-series data inspection unit 22a and a selector IC abnormality determination unit 22b. The

  The time-series data inspection unit 22a is a unit that inputs the output from the signal output terminal 21b of the selector IC 21 and inspects the time-series data of the detection signals for the sensors 11 to 18.

  In this time-series inspection means 22a, the time-series data Di of the detection signals of the sensors 11 to 18 to be inspected deviates from the range between the upper limit Du and the lower limit Dd set in advance for each of the sensors 11 to 18 to be inspected. When the number N1out of data Diout is greater than or equal to a preset first deviation number Nc1, it is determined that there is an abnormality.

  Further, with respect to the inspection time Td and data width ΔD preset for each of the sensors 11 to 18 to be inspected, the time series data Di to be inspected is data Djout that goes outside the data width ΔD within the inspection time Td. Is equal to or less than the preset second deviation number Nc2, that is, when the time-series data Di does not change during the inspection time Td, it is determined to be abnormal.

  These upper limit value Du, lower limit value Dd, inspection time Td, data width ΔD, first deviation number, second deviation number, etc. are set according to the characteristics of the target sensor and the degree of influence of the detected value of the sensor in the control. Is done.

  Further, the selector IC abnormality determination means 22b uses the inspection signal sensor determined to be abnormal as an abnormality signal sensor based on the inspection result of the time-series inspection means 22a, and normalizes the inspection signal sensor determined to be normal. When the number Nun of abnormal signal sensors is greater than the preset number Nα of abnormality determination ratios α with respect to the number Nst of all sensors when the signal sensor is used, the selector IC 21 is connected regardless of the output of the error signal terminal 21d. It is a means to determine that it is abnormal.

  This abnormality determination ratio α is actually set according to the characteristics of the target sensors 11 to 18, the degree of influence of the detected values of the sensors 11 to 18 in the control, and the sensitivity of the device to be controlled. The determination ratio α is set to 60%, but depending on the case, it is set to 80%, 90%, 100% (total number).

  In addition, when some specific sensors are selected and some of these selected sensors are included in the abnormal signal sensor, the number Nun of the abnormal signal sensors is the total number connected to the selector IC 21. Even if it is smaller than the preset number Nα of the abnormality determination ratio α with respect to the number Nst of sensors, the selector IC 21 may be determined to be abnormal. Furthermore, it may be configured such that a failure determination weight is given to each of the sensors 11 to 18 and abnormality is determined by the number Nunm of weighted abnormality signal sensors.

  The time series inspection means 22a and the selector IC abnormality determination means 22b preferably operate at all times when the control system 1 is operating, that is, always perform abnormality determination. However, in consideration of safety and controllability, the function may be operated at predetermined time intervals.

  Next, the failure diagnosis method for the control system according to the embodiment of the present invention will be described. This method outputs a selector 21a that receives signals from a plurality of sensors 11 to 18, a signal output terminal 21b that outputs an output signal of the selector 21a, an internal diagnostic circuit 21c, and a diagnostic result in the internal diagnostic circuit 21c. This is a failure diagnosis method for a control system including a selector IC 21 having an error signal terminal 21d and a central processing unit 22. An output from a signal output terminal 21b of the selector IC 21 is input to detect each sensor 11-18. The time series data Di of the signal is inspected, the inspection signal sensor determined to be abnormal is the abnormal signal sensor, the inspection signal sensor determined to be normal is the normal signal sensor, and the number of abnormal signal sensors is Nun is larger than the number Nα of preset abnormality determination ratios α with respect to the number Nst of all sensors connected to the selector IC 21. If it is not, the selector IC 21 is determined to be abnormal regardless of the output of the error signal terminal 21d.

  According to the control system 1 and the control system failure diagnosis method configured as described above, even if the selector IC 21 falls into a failure in which it cannot notify its own error, it is determined that the abnormality is detected by the abnormality determination on the central processing unit 22 side. When this abnormal state is detected, it is possible to switch to control for protection of equipment such as an engine controlled by the control system 1, and to ensure safety and minimum vehicle operation.

  Further, when the control system 1 controls a vehicle equipped with an internal combustion engine, many sensors are used, and since it is important to ensure the safety of the crew, the merit of the present invention can be used more effectively.

1 Control System 10 Signal Device (Sensor Group)
11 Speed sensor 12 Water temperature sensor 13 Engine water temperature sensor 14 Fuel temperature sensor 15 Intake temperature sensor 16 Exhaust temperature sensor 17 Atmospheric pressure sensor 18 Boost pressure sensor 20 Control device (ECM)
21 Selector IC
21a selector 21c internal diagnostic circuit 21b signal output terminal 21d error signal terminal 22 central processing unit (CPU)
22a Time series data inspection means 22b Abnormality determination means

Claims (5)

A selector IC having a selector for receiving signals from a plurality of sensors, a signal output terminal for outputting an output signal of the selector, an internal diagnostic circuit, and an error signal terminal for outputting a diagnostic result in the internal diagnostic circuit; In a control system equipped with a processing device,
The central processing unit includes an output from a signal output terminal of the selector IC, and includes time-series data inspection means for inspecting time-series data of detection signals for each sensor,
The abnormality signal when the sensor of the inspection signal determined to be abnormal is an abnormal signal sensor and the sensor of the inspection signal determined to be normal is the normal signal sensor based on the inspection result by the time-series inspection means. When the number of sensors is larger than the number of preset abnormality determination ratios with respect to the total number of sensors connected to the selector IC, it is determined that the selector IC is abnormal regardless of the output of the error signal terminal. A control system comprising selector IC abnormality determination means.   The time-series inspection means sets the number of data in which the time-series data of the detection signal of the sensor to be inspected deviates from the range of the upper limit value and the lower limit value preset for each sensor to be inspected. It is determined that there is an abnormality when the number of deviations is one or more, and the time-series data to be inspected is within the inspection time with respect to the inspection time and data width preset for each of the sensors to be inspected. 2. The control system according to claim 1, wherein the control system is configured to determine that there is an abnormality when the number of data items outside the data width is equal to or less than a preset second deviation number.   The control system according to claim 1 or 2, wherein the abnormality determination ratio is 60%.   The control system according to claim 1, wherein the control system controls a vehicle equipped with an internal combustion engine. A selector IC having a selector for receiving signals from a plurality of sensors, a signal output terminal for outputting an output signal of the selector, an internal diagnostic circuit, and an error signal terminal for outputting a diagnostic result in the internal diagnostic circuit; In a fault diagnosis method for a control system provided with a processing device,
The output from the signal output terminal of the selector IC is input, the time series data of the detection signal for each sensor is inspected, and the sensor of the inspection signal determined to be abnormal is an abnormal signal sensor, which is normal If the sensor of the inspection signal determined to be a normal signal sensor and the number of abnormal signal sensors is greater than the number of preset abnormality determination ratios relative to the number of all sensors connected to the selector IC, the error A failure diagnosis method for a control system, wherein the selector IC is determined to be abnormal regardless of the output of a signal terminal.

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