JPS62220881A - Fault diagnosis device for actuator - Google Patents

Abstract

PURPOSE:To detect the abnormality of an actuator by the same means without reference to the short circuit and wire breaking of a power source by detecting whether or not there is a driving signal output corresponding to a specific manipulated variable. CONSTITUTION:The output signal (b) of an edge detecting means 36 is at the GND level while the transistor (TR) of a driving signal output means 32 is in a stationary on or off state with the output signal (a) of a manipulated variable output means 31. Further, when the signal (a) is switched from +5V to the GND level, the CR circuit in the edge detecting means 36 detects an edge and the signal (b) is held at a voltage determined by a reference voltage generating means 35. When the actuator is normal at this time, a surge is generated by the coil component of the actuator, a signal (d) is lower than a reference voltage, and the signal (e) is still at the GND level. If the actuator is abnormal, the signal (d) is below the reference voltage and the signal (e) is at +5V.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to failure diagnosis of an actuator using a coil, and more particularly to an actuator failure diagnosis apparatus for an actuator control system using an electronic control unit.

[Conventional technology]

Conventionally, actuator failure diagnosis devices have determined whether current is flowing through the actuator and whether the voltage at a certain measurement point is above or below a reference voltage by performing logical operations. For example, as shown in FIG. 2, when the actuator 21 and the switch 22 that turns it ON and OFF are connected, the comparison voltage V is the two states of the switch 22, 0N0OFF, and the actuator 21.
Normal.

Short circuit to power supply VAA. Depending on the three states of disconnection, there are six states shown in Table 1.

Table 1 [Problems to be Solved by the Invention] In the conventional actuator diagnostic device described above, as can be seen from Table 1, the short circuit diagnosis to the power supply VAA is performed only at the switch 22.
It can be detected only when the switch 22 is turned on, and a disconnection can only be detected when the switch 22 is turned off.

However, the actuator failure diagnosis apparatus does not originally need to diagnose whether the actuator is short-circuited or disconnected from the power supply V, U4C, but only needs to be able to detect that the actuator is in an abnormal state. Having a means for detecting a short circuit to the power supply VAA and a means for detecting a disconnection by changing the judgment criteria depending on whether the actuator is ON or OFF makes the device complicated and even worse. This leads to increased costs.

The object of the present invention is to solve the above-mentioned drawbacks and to short-circuit the abnormality of the actuator to the power supply VAA. It is an object of the present invention to provide an actuator failure diagnosis device that can detect wire breakage by the same means. An operator output means that generates a signal according to the operation -1tK, a drive signal output means to which the output signal of the manipulated variable output means is input, and a power generated by the excitation force of a coil to which the output of the drive signal output means is input. an actuator that obtains the output signal of the reference voltage generating means and the drive input to the actuator; and failure determination means for comparing the output of the signal output means.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a circuit diagram of an embodiment of the present invention.

In FIG. 3, 31 is a manipulated variable output means, 32 is a drive signal output means using a transistor, 33 is an actuator, 34 is a comparison voltage generation means using resistance division, 35 is a reference voltage generation means using a Zener diode, and 36 is an OR circuit. The edge detection means 37 is a failure determination means using an operational amplifier 38 and a 7-lip flop 39.

In Fig. 3, the output signal of the manipulated variable output means 31 is +5V, GN.
The signals of each part are shown when a rectangular wave of D (ground voltage) is applied.

When the transistor of the drive signal output means 32 is statically turned ON or OFF by the output signal a of the manipulated variable output means 31, the output signal of the operation amount detection means 36 is at the GND level. Become. Actuator 33
The signal OX between the drive signal output means 32 and the drive signal output means 32 is used as the power supply VAA when the transistor of the drive signal output means 32 is OPP, and when the transistor of the drive signal output means 32 is ON, the saturation voltage of the transistor is higher than the GND level, so a comparison voltage is generated. Means 3
The output signal d of the operational amplifier 38 does not go to the GND level, and the output signal e of the operational amplifier 38 goes to the GND level. But signal a
When the voltage changes from +5V to GND level, the edge is detected by the OR circuit in the edge detection means 36, and the signal becomes the voltage determined by the reference voltage generation means 35. If the actuator 31 is normal at this time, a surge will occur due to the coil component of the actuator 31.
This surge voltage causes the signal d to become higher than the reference voltage, and the signal e remains at the GND level. However, if the actuator 33 is short-circuited or disconnected from the power supply VAA, a surge due to the coil component of the actuator will not occur, and therefore the reference voltage of the signal d will be low, and the signal e will be at the +5V level.

The flip-flop 39 has an abnormality in the actuator and a signal e is generated.
When the voltage reaches 5v level, the output changes from GND level to 5v.
change to the level.

〔Effect of the invention〕

As described above, the actuator failure diagnosis device of the present invention does not require separate means for detecting a short circuit to a power source and detecting a disconnection, unlike conventional methods, and the device can be simplified. This has the effect of reducing costs.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram of an embodiment of the present invention, Fig. 2 is a circuit diagram for explaining the principle of a conventional actuator failure diagnosis device, and Fig. 3 is the same as Fig. 1. 5 is a time chart of each signal in the example shown in FIG. In the figure, 31... manipulated variable output means 32.
... Drive signal output means 33 ... Actuator 34 ... Comparison voltage generation means 35 ...
. . . Reference voltage generation means 36 . . . Detection means 37 . . . Failure determination means. Dyeing 1 @ Thing 2

Claims (1)

[Claims] A manipulated variable output means that generates a signal corresponding to a predetermined manipulated variable, a drive signal output means to which the output signal of the manipulated variable output means is input, and a coil to which the output of the drive signal output means is input. an actuator that obtains power from an excitation force; a reference voltage generation means that outputs a predetermined voltage signal when switching the signal generated by the manipulated variable output means; and an output signal of the reference voltage generation means and input to the actuator. an actuator failure diagnosis device, comprising: failure determination means for comparing the output of the drive signal output means with the output of the drive signal output means.