JP4192638B2 - Electronic control device function inspection method and function inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a function inspection method and a function inspection apparatus, and more particularly to a function inspection method and apparatus for a circuit element group mounted on an electronic control device.
[0002]
[Prior art]
Conventionally, a normality confirmation test of an electronic control unit (ECU) includes a function test for confirming electrical continuity of a circuit element mounted on the electronic control unit, and an electrical characteristic of each circuit element by an in-circuit tester. It is implemented in combination with the mounting inspection to confirm.
[0003]
Mounting inspection by an in-circuit tester is performed by applying a probe pin to each circuit element, but in general, a set of probe pins is not applied to each circuit element each time, but in advance according to the configuration pattern of the circuit elements on the substrate. This is done using a pin board on which probe pins are arranged.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-280889 [Patent Document 2]
JP 58-123470 A [Patent Document 3]
Japanese Patent Laid-Open No. 11-65873
[Problems to be solved by the invention]
However, in recent years, the number of circuit elements mounted on an electronic control device has increased and is highly integrated. Therefore, the number of probe pins on the pin board is increased and the arrangement thereof is complicated, and it is difficult to apply these pins to each circuit element, which causes a problem of high integration.
[0006]
The present invention has been made in view of the above problems, and an object thereof is to narrow the inspection range of the in-circuit test and reduce the number of probe pins.
[0007]
[Means for Solving the Problems]
A function inspection method according to the present invention is a function inspection method for performing a function inspection of a circuit element group mounted on an electronic control device controlled by a control microprocessor, and the function inspection method is a time-series output from the control microprocessor. An inspection reference range in which a response curve obtained based at least on an input step of inputting a test signal that changes into a circuit element group and an output voltage value of a response test signal to the test signal output from the circuit element group is predetermined. look including a determination step of determining whether there within, the inspection reference range, the output of the response test signal is determined on the basis of a predetermined tolerance voltage for the output voltage of the control microprocessor The upper limit value of the voltage value and the relative resistance value or the relative value of the tolerance capacitance determined in advance for the circuit element group. The lower upper limit value of the upper limit value of the force voltage value, and the lower limit value of the output voltage value determined based on the tolerance voltage and the output voltage determined based on the relative value of the tolerance resistance value or tolerance electric capacity It is characterized in that it is determined based on the higher lower limit value among the lower limit values .
[0008]
A function testing apparatus according to the present invention is a function testing apparatus that performs a function test of a circuit element group mounted on an electronic control device controlled by a control microprocessor, and that is output over time from the control microprocessor. An input terminal for inputting a response test signal of the circuit element group with respect to a test signal that changes to a test signal, and a response curve obtained based at least on the output voltage value of the response test signal of the circuit element group are within a predetermined test range. e Bei and determining circuit whether the test reference range, the output voltage value of the response test signal is determined on the basis of a predetermined tolerance voltage for the output voltage of the control microprocessor And the output voltage determined based on a tolerance resistance value or a relative value of a tolerance capacitance predetermined for the circuit element group. The lower limit value of the output voltage value determined based on the lower limit value of the output voltage value determined based on the tolerance voltage and the relative value of the tolerance resistance value or the tolerance capacitance It is characterized in that it is determined based on the higher lower limit value among the values.
[0009]
According to the present invention, in a so-called function test, by inputting a waveform signal that changes over time to a circuit element group provided in the ECU and determining whether or not its response curve is within the test reference range, Not only the electrical continuity of the circuit element group can be confirmed, but also the electrical characteristics of the capacitor and coil can be inspected. Therefore, since the target range of the circuit element group whose electrical characteristics are inspected by the in-circuit tester is narrowed, mounting inspection by the in-circuit tester is unnecessary or the number of probe pins can be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
Hereinafter, a first embodiment of the present invention (hereinafter referred to as a first embodiment) will be described with reference to the drawings.
[0011]
In the first embodiment, the electrical components of the circuit element group built in the electronic control unit (ECU) are based on the response waveform of the inspection signal output from the ECU in response to the inspection signal (waveform signal) from the inspection device. It is to inspect the characteristics.
[0012]
Here, the ECU is, for example, a device provided in a vehicle that controls the entire vehicle such as a drive system, a control system, and a steering system based on various sensors (temperature sensor, rotation sensor, etc.) provided in the vehicle. is there.
[0013]
FIG. 1 is a circuit configuration diagram according to the first embodiment, in which an inspection apparatus 10 and an ECU 20 to be inspected are connected to each other through an input port and an output port.
[0014]
In the inspection apparatus 10, the control unit 11 issues a command to the command signal generation unit 12 so as to output an inspection signal to the microcomputer unit 21 (control microprocessor). In response to this, the command signal generator 12 outputs a command signal to the microcomputer unit 21.
[0015]
The command signal output from the command signal generation unit 12 is converted from a digital signal to an analog signal by the DA conversion unit 13, passes through the input port of the ECU 20, and is input to the microcomputer unit 21.
[0016]
When the command signal converted into the analog signal is input, the microcomputer unit 21 outputs an inspection signal that is an analog signal corresponding to the command signal. Here, the inspection signal (waveform signal) is a signal that changes over time, and is, for example, a step waveform (FIG. 2A) or a sine wave (FIG. 2B).
[0017]
This inspection signal is output from the output port 24 through the circuit element group 22 to be inspected. The circuit element group 22 is, for example, an LPF (low-pass filter) or a transistor amplifier circuit. FIG. 3 shows a circuit configuration diagram in the case of the LPF.
[0018]
The output inspection signal is converted into a digital signal by the AD conversion unit 14, passes through an HPF (high pass filter) unit 15, removes low-frequency noise, and then input to the determination unit 16.
[0019]
The determination unit 16 determines whether or not the circuit element group 22 to be inspected is acceptable depending on whether the response curve of the inspection signal is within the inspection reference range stored in the storage unit 17. Here, when the response curve is within the inspection reference range, it is determined as acceptable, and when it is not within the range, it is determined as unacceptable.
[0020]
Here, the response curve will be further described. When the inspection signal output from the microcomputer unit 21 has a step waveform as shown in FIG. 2A, the vertical axis represents the voltage Vf (t) of the inspection signal input to the determination unit 16, and the horizontal axis represents Vf (t ) Is obtained as the following equation as S (t) obtained by integrating.
[0021]
S (t) = S (t-1) + Vf (t)
[0022]
The response curve based on the above equation is as shown by a solid line portion 1 shown in FIG. If this response curve is between the upper limit 2 and the lower limit 3 of the inspection reference range, it is determined as acceptable.
[0023]
In addition, there is an effect that white noise can be removed by integrating Vf (t).
[0024]
By the way, when the horizontal axis is not the integrated value S (t) but the time T (t), the ECU 20 processes the signal and outputs the inspection signal after the inspection signal is output from the inspection device 10. Since the processing time in each part varies, the origin of the response curve is shifted. Therefore, it is difficult to determine whether the response curve is within the inspection reference range.
[0025]
However, as described above, the HPV unit 15 corrects the 0V level, integrates Vf (t), and removes white noise, so that the original response curve can be extracted. Until S is output, S (t) circulates in the vicinity of the origin, so that the origin deviation can be prevented. Therefore, it can be accurately determined whether or not the response curve is within the inspection reference range.
[0026]
Furthermore, a response curve when the inspection signal output from the microcomputer unit 21 is a sine wave as shown in FIG. 2B will be described. In the case of a sine wave, the HPF unit 15 is not used, and the circuit configuration is as shown in FIG.
[0027]
In this case, the vertical axis of the response curve indicates that the output voltage of the inspection signal (sine wave) output from the microcomputer unit 21 of the ECU 20 is Vout (t), and the inspection is input to the inspection apparatus 10 through the circuit element group 22. The input voltage of the signal is represented by Vin / Vout, where Vin (t). The horizontal axis indicates the frequency (Hz) of the sine wave output from the microcomputer unit 21.
[0028]
Then, the response curve 1 becomes like a solid line portion shown in FIG. In this case as well, if the response curve is between the upper limit 2 and the lower limit 3 of the inspection reference range, it is determined to be acceptable.
[0029]
Next, a method for calculating the upper and lower limits of the inspection reference range will be described.
[0030]
The inspection reference range can be determined by the absolute value (voltage value) of the output voltage tolerance Ve in the microcomputer unit 21, the tolerance resistance value Re of the circuit element group 22, and the relative value (%) of the tolerance electric capacity Ce.
[0031]
Of these tolerances, when using only absolute values, the upper and lower limits are
[0032]
(Upper limit value) = Vf (t) + ΔV
(Lower limit value) = Vf (t) −ΔV
It becomes.
[0033]
When only relative values are used, the upper and lower limits are
(Upper limit value) = Vf (t) (1 + r / 100)
(Lower limit value) = Vf (t) (1-r / 100)
It becomes.
[0034]
Furthermore, when using absolute and relative values together (maximum error),
(Upper limit value) = Vf (t) + (ΔV + r · V (f) / 100)
(Lower limit value) = Vf (t) − (ΔV + r · V (f) / 100)
It becomes.
[0035]
In addition, when using the stricter of absolute and relative values (when the pass range is narrow),
(Upper limit value) = min (Vf (t) + ΔV, Vf (t) (1 + r / 100))
(Lower limit value) = max (Vf (t) −ΔV, Vf (t) (1−r / 100))
It becomes.
[0036]
A value is determined from these upper limit value and lower limit value according to the inspection standard, and stored in the storage unit 17. Based on the inspection reference range determined from the stored upper limit value and lower limit value, the determination unit 16 inspects the electrical characteristics of the circuit element group 22.
[0037]
As described above, by inputting a step waveform or a sine wave that changes over time to the circuit element group and determining whether or not the response curve is within the above upper and lower limits, in a so-called function test, Not only the electrical continuity of the circuit element group can be confirmed, but also the electrical characteristics of the capacitor and coil can be inspected. Accordingly, the number of circuit element groups for inspecting electrical characteristics by the in-circuit tester can be reduced, so that mounting inspection by the in-circuit tester is unnecessary or the number of probe pins can be reduced.
[Second Embodiment]
Subsequently, a second embodiment (hereinafter referred to as a second embodiment) of the present invention will be described with reference to the drawings.
[0038]
The second embodiment relates to an inspection in a case where a plurality of circuit element groups are provided in an ECU to be inspected.
[0039]
As shown in FIG. 6, the inspection apparatus 10 according to the second embodiment has a configuration in which a switching unit 18 is further added to the inspection apparatus 10 according to the first embodiment. Then, the inspection apparatus 10 operates the switching unit 18 according to a command from the control unit 11 to switch the circuit element group to be inspected.
[0040]
The control unit 11 stores information on each circuit element group in the ECU in advance, and instructs the command signal generation unit 12 to output a command signal corresponding to the circuit element group to be inspected according to the inspection contents. And issues a command to the switching unit 18 to switch to the circuit that connects the circuit element group to be inspected and the inspection device.
[0041]
Thus, by providing the switching unit 18, even when a plurality of circuit element groups exist in the ECU, the electrical characteristics of each circuit element group can be inspected quickly, and the cost of the inspection apparatus can be reduced. .
[0042]
After switching the circuit element group to be inspected by the switching unit 18, the inspection is performed by determining whether or not the response curve of each circuit element group is within the inspection reference range, as in the first embodiment.
[0043]
As a form other than the first and second embodiments, as shown in FIG. 7, a command (digital signal) is directly issued from the inspection apparatus 10 to the ECU 20 (a command is issued from a system different from the input / output port), and the ECU The electrical characteristics of the circuit element group built in the ECU may be inspected based on the inspection signal output from the ECU.
[0044]
In addition, as shown in FIG. 8, the inspection apparatus 10 may be provided with an inspection signal output section instead of the command signal generation section 12 so that an inspection signal is directly generated from the inspection apparatus for inspection. . In that case, the inspection apparatus 10 further adds a resistance between the DA conversion unit 13 and the AD conversion unit 14 of the inspection apparatus 10 and connects it to the circuit element group.
[0045]
With this configuration, the inspection can be performed based on the response waveform of the circuit element group with respect to the inspection signal output from the inspection apparatus 10.
[0046]
As shown in FIG. 9, when there are a plurality of circuit element groups to be inspected in one ECU (as in the second embodiment), the resistance is a variable resistance and the resistance corresponding to each circuit element group You may comprise so that it may become a value.
[0047]
【The invention's effect】
According to the present invention, a step waveform or a sine wave that changes over time is input to a circuit element group provided in the ECU, and it is so-called by determining whether or not the response curve is within the inspection reference range. In the function inspection, not only the electrical continuity confirmation of the circuit element group but also the electrical characteristics of the capacitor and the coil can be inspected. Therefore, since the target range of the circuit element group whose electrical characteristics are inspected by the in-circuit tester is narrowed, mounting inspection by the in-circuit tester is unnecessary or the number of probe pins can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of an inspection apparatus and an ECU according to a first embodiment.
FIG. 2 is an example of a waveform signal (inspection signal) used for the function inspection of the present invention ((a) step waveform, (b) sine wave).
FIG. 3 is a circuit configuration diagram when a circuit element group is an LPF.
FIG. 4 is an example of a response curve ((a) step waveform response curve, (b) sinusoidal response curve).
FIG. 5 is an example of a circuit configuration diagram of an inspection apparatus and an ECU according to the present invention.
FIG. 6 is an example of a circuit configuration diagram of the inspection apparatus and ECU of the present invention.
FIG. 7 is an example of a circuit configuration diagram of the inspection apparatus and ECU of the present invention.
FIG. 8 is an example of a circuit configuration diagram of the inspection apparatus and ECU of the present invention.
FIG. 9 is an example of a circuit configuration diagram of an inspection apparatus and an ECU according to the present invention.
[Explanation of symbols]
1 response curve, 2 upper limit, 3 lower limit, 10 inspection device, 11 control unit, 12 command signal generation unit, 13 DA conversion unit, 14 AD conversion unit, 16 determination unit, 17 storage unit, 18 switching unit, 21 microcomputer unit, 22 Circuit element group.

Claims (2)

A function inspection method for performing a function inspection of a circuit element group mounted on an electronic control device controlled by a control microprocessor,
An input step of inputting a test signal output from the control microprocessor, which changes over time, to the circuit element group;
Look including a determination step of determining whether the response curve obtained based at least on is within the test reference range predetermined for the output voltage value of the response test signal to the test signal output from the circuit element group,
The inspection reference range is predetermined for an upper limit value of the output voltage value of the response inspection signal determined based on a tolerance voltage predetermined for an output voltage of the control microprocessor and for the circuit element group. A lower upper limit value among the upper limit values of the output voltage value determined based on the determined tolerance resistance value or relative value of the tolerance electric capacity, and a lower limit value of the output voltage value determined based on the tolerance voltage; The lower limit value of the lower limit value of the output voltage value determined based on the tolerance resistance value or the relative value of the tolerance electric capacity, is determined based on,
Function inspection method according to claim. A function inspection device for performing a function inspection of a circuit element group mounted on an electronic control device controlled by a control microprocessor,
  An input terminal for inputting a response test signal of the circuit element group with respect to a test signal that changes over time output from the control microprocessor;
A determination circuit that determines whether or not a response curve obtained based on at least an output voltage value of the response inspection signal of the circuit element group is within a predetermined inspection range;
The inspection reference range is predetermined for an upper limit value of the output voltage value of the response inspection signal determined based on a tolerance voltage predetermined for the output voltage of the control microprocessor and the circuit element group. A lower upper limit value among the upper limit values of the output voltage value determined based on the determined tolerance resistance value or the relative value of the tolerance electric capacity, and a lower limit value of the output voltage value determined based on the tolerance voltage; The lower limit value of the lower limit value of the output voltage value determined based on the tolerance resistance value or the relative value of the tolerance electric capacity, is determined based on,
Functional inspection device characterized by

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