JP2000162249A - Detecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To distinguish an abnormality at a detecting means from an abnormality at an A/D converter in a detecting apparatus, provided with detecting means such as a current sensor or the like and the A/D converter. SOLUTION: This detecting apparatus detects a current amount set to a predetermined reference value by a current sensor 12, outputs the amount as an electrical signal and converts the output signal into a digital signal by a first and a second A/D converters 22 and 26. The digital signal after conversion is compared with a reference output value stored in a memory 32 by an abnormality-detecting part 30 in a CPU. When either of actual output values from the first A/D converter 22 and the second A/D converter 26 deviates from the reference output value, it is discriminated that an abnormality has taken place at one of the converters 22, 26. When both output values from the converters 22 and 26 deviate from the reference output value, it is discriminated that an abnormality has taken place in the current sensor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection device for detecting a physical quantity set to a predetermined value, for example, a current or a voltage, as an electric signal and outputting the electric signal as a digital signal. The present invention relates to a detection device having an abnormality detection function for detecting an abnormality.

[0002]

2. Description of the Related Art An electric vehicle or a hybrid vehicle that obtains vehicle driving force by an electric motor is equipped with a secondary battery (hereinafter simply referred to as a battery), and the electric power stored in the battery (hereinafter referred to as a stored electric power). Drives the electric motor. Such an electric vehicle has regenerative braking, that is, a function in which an electric motor functions as a generator at the time of vehicle braking, and a function of braking by converting kinetic energy of the vehicle into electric energy. The converted electric energy is stored in a battery and is reused when accelerating.

However, if the battery is overdischarged or overcharged, the performance of the battery will be degraded.
It is necessary to calculate OC (state of charge) and adjust charge / discharge. In particular, in a hybrid vehicle in which a generator is driven by a heat engine mounted on a vehicle to generate electric power and the electric power can be charged to a battery, it is required that the stored amount of the battery be able to accept regenerative electric power. In order to be able to supply electric power to the motor as soon as possible, the amount of stored electric power is approximately in the middle (50%) between the fully charged state (100%) and the state where no electric power is stored (0%).
〜60%). Therefore, in a hybrid vehicle, it is desired to more accurately detect the charged amount of the battery.

[0004] As a device for detecting the charged amount of a battery, a method of detecting based on the terminal voltage of the battery is well known. However, since the terminal voltage changes depending on the current, in recent years, a device that includes a voltage sensor and a current sensor and detects the amount of stored power using both the terminal voltage and the current has been developed. One example is JP-A-9-72984. In addition, depending on the type of battery, in an area having a charged amount, the charged amount does not appear in the external characteristics of the battery.
In this case, a method is employed in which the charge / discharge current detected by the current sensor is integrated to estimate the charged amount.

When estimating the charged amount based on the detected value of the voltage sensor or the current sensor, the detected value detected by the voltage sensor or the current sensor is usually output to the A / D converter as an electric signal. Here, it is converted into a digital signal and output to the CPU. The CPU estimates the charged amount based on the output value, and controls charging and discharging of the battery.

[0006]

As described above, when estimating the charged amount based on the detection values of the voltage sensor and the current sensor, a voltage sensor for detecting a current and a voltage, a current sensor, and a signal from these sensors. It is a natural premise that the A / D converter for converting the output operates normally. That is, when an abnormality occurs in these current sensors and A / D converters, the amount of stored power cannot be estimated, and an incorrect amount of stored power is estimated. Therefore, in order to perform reliable estimation of the amount of stored power, when an abnormality occurs in the voltage sensor, the current sensor, or the A / D converter, the abnormality is detected early, and the part where the abnormality occurs is detected. Need to be identified and repaired.

However, since the output from the current sensor or the voltage sensor is finally output to the CPU via the A / D converter and appears outside, whether an abnormality has occurred in the voltage sensor or the current sensor, or It has been difficult to identify whether an abnormality has occurred in the A / D converter. Also,
Conventionally, such identification is performed manually by a worker at the time of repair, and is a labor-intensive operation.

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a detecting apparatus having an A / D converter and a detecting means such as a current sensor or a voltage sensor as described above. An object of the present invention is to discriminate an abnormality occurring in the means from an abnormality occurring in the A / D converter and to detect the abnormality.

[0009]

In order to achieve the above object, a detection device of the present invention detects a physical quantity set to a predetermined reference value at a predetermined measurement position and outputs it as an electric signal; First conversion means for converting the electric signal output from the detection means to a digital signal, second conversion means for converting the electric signal output from the detection means to a digital signal, and the first conversion means A reference output value storage means in which a reference output value after conversion in the second conversion means is stored in advance, connected to the outputs of the first and second conversion means, Abnormality detection means for comparing the reference output value in the reference output value storage means with the abnormality in the conversion means and the abnormality in the detection means to detect the abnormality and detect the abnormality.

According to the above invention, a physical quantity such as a voltage or a current set to a predetermined reference value by the detection means is detected at a predetermined measurement position and output as an electric signal, and this output signal is output to the first and second signals. The signal is converted into a digital signal by the conversion means. The converted digital signal is compared with the reference output value stored in the reference output value storage means in the abnormality detection means. Here, if one of the output values from the first conversion means and the second conversion means is out of the reference output value, it is determined that an abnormality has occurred in this one conversion means, and If both the output values from the first conversion means and the second conversion means deviate from the reference output value, it is determined that an abnormality has occurred in the detection means.
As described above, according to the present detection device, it is possible to detect the abnormality of the conversion unit and the abnormality of the detection unit separately, and thus it is possible to improve the efficiency of inspection and repair of the detection device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of the detection device of the present embodiment. Here, a description will be given of an example of a current detection device that detects a current in a system that calculates a charged amount of a secondary battery mounted on an electric vehicle.

In FIG. 1, a battery 10 is provided with a current sensor 12 as a current detecting means for estimating the amount of charge in the battery of the electric vehicle based on the charge / discharge current. The current sensor 12 detects a charging / discharging current flowing in the battery 10 as a physical quantity and outputs it as an electric signal. The output 16 of the current sensor 12 extends into the battery ECU 18 and is branched into two. One is connected to the amplifier 20 and the first A / D converter 22, and the other is connected to the amplifier 24 and the second A / D converter 26. Is done. These amplifiers 20 and 24 are connected to the current sensor 12.
Amplifies the electric signal output from the first and second A / D
The amplified signals are input to converters 22 and 26. The first and second A / D converters 22 and 26 convert the input amplified signals into digital signals and output the digital signals.

Here, the first and second converters 22, 26 are used.
Can have the same gain and perform A / D conversion in parallel in both cases, but preferably, the gains of the converters 22 and 26 are set differently. For example, the first A / D converter 22 is set to full scale, and the other second A / D converter 22 is used.
By making the gains of the two A / D converters 22 and 26 different so that the D converter 26 has a limited scale, the A / D converters 22 and 26 are switched according to the measurement current in the current sensor 12 to achieve high resolution and achieve high resolution. The detection sensitivity of the value can also be increased.

More specifically, the first A / D converter 22 has a range of 10A, and the second A / D converter 26 has a range of 100A.
When the range of the measurement is, the measured current of the current sensor is 10 A
In the following cases, A / D conversion is performed by the first A / D converter 22. In the case of a measured current exceeding 10 A, A / D conversion is performed by the second A / D converter 26. . By switching the first and second A / D converters 22 and 26 in accordance with the measured current in this manner, it is possible to appropriately detect the current value, and it is possible to increase the accuracy of calculating the amount of stored power described below.

The outputs of the first and second A / D converters 22 and 26 are both connected to a CPU 28 and output from the first and second A / D converters.
The signals converted by the converters 22 and 26 are sent to the CPU 28
Is input to This conversion signal is input to the charged amount calculating unit 29 in the CPU 28, and the charged amount of the battery 10 is calculated. There is no particular limitation on the method of calculating the battery charge amount in the charge amount calculating unit 29, and various methods can be adopted. For example, in the method of integrating the charge / discharge current used in electric vehicles, first, the relay of the battery 10 is turned off, and when the current is 0, the input value input to the CPU 28 is recorded in the memory (RAM) 32. Then, this input value is stored as a zero point offset value. And the battery 10
Is detected by the current sensor 12.
The current detected by the current sensor 12 is finally input to the CPU 28 via the A / D converters 22 and 26, and stored in the storage amount calculator 29 by integrating the value obtained by subtracting the zero point offset value. An amount calculation is performed.

In order to ensure the reliability of the calculation of the charged amount based on the discharge current, a current sensor 1 is provided in the CPU 28.
An abnormality detection unit 30 that detects an abnormality of the two and two A / D converters 22 and 26 is provided. This abnormality detection unit 30
Compares the reference output value recorded in the memory 32 functioning as reference output value recording means with the actually measured output value,
It is determined whether or not the actually measured output value corresponds to the reference output value, and it is detected whether or not the current sensor 12 and the first and second A / D converters 22 and 26 are abnormal.

In detail, the reference output value recorded in the memory 32 is such that the first and second A / D converters 22 and 2
6 is an estimated reference output value output to the CPU 28 through the CPU 6. Here, “the current amount set to the predetermined reference value”
Is not particularly limited and may be any value suitable for measurement. Preferably, the current amount is 0 A, which is the current amount when the relay 14 of the battery 10 is turned off. As described above, when the current amount of the predetermined reference value in the battery 10 is set to 0 A, it is possible to perform the abnormality determination simultaneously with the measurement of the zero point offset value required for the above-described calculation of the charged amount. Hereinafter, the detection operation of the abnormality detection unit will be described in more detail with reference to the flowchart of FIG.

In FIG. 2, when the abnormality detection operation is started (S01), for example, the relay 14 of the battery 10 is turned off and the detection current of the battery sensor 12 becomes 0A (S02).
When the current amount reaches the reference value, the abnormality detection unit 30
Acquires the output value (A) output from the first A / D converter 22 (S03). Similarly, the abnormality detection unit 30 acquires the output value (B) output from the second A / D converter 26 (S04).

The abnormality detector 30 compares the output values obtained from these two A / D converters with the reference output value recorded in the memory 32, and determines whether the difference is within a predetermined normal range. The determination is made in the order of the output value (A) and then the output value (B), and if it is out of this range, it is determined to be an abnormal value (S05, 06, 09).

Here, the output value (A) is a normal value (S
05), if the output value (B) is determined to be a normal value (S06), the current sensor 12 and the two A / D converters 2
2 and 26 are all determined to be normal (S07). on the other hand,
If the output value (A) is a normal value (S05), but the output value (B) is determined to be an abnormal value (S06), an abnormality of the second A / D converter 26 is detected (S08). ).

The output value (A) is an abnormal value (S0
5) If the output value (B) is determined to be a normal value (S
09), the first A / D converter 22 is determined to be abnormal (S)
10). On the other hand, the output value (A) is an abnormal value (S0
5) If the output value (B) is determined to be an abnormal value (S0
9), an abnormality of the current sensor 12 is detected (S1).
1). As described above, the present detection device can distinguish and detect the abnormality between the current sensor and the converter, so that when an abnormality occurs, it is possible to automatically determine which part has the cause, and perform inspection and repair. And other operations can be facilitated.

Although the current sensor is shown as the detecting means in the above-described detecting device, other physical quantities such as a voltage sensor for detecting a voltage, a temperature sensor for detecting a temperature, and an optical sensor for detecting a light quantity may be used. Means to do so is included.

[0023]

As described above, according to the detecting device of the present invention, the abnormality of the detecting means and the abnormality of the converting means are automatically distinguished and detected, so that the repair or the like conventionally performed by the worker can be performed. It is possible to simplify the abnormality detection operation at the time of inspection.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a detection device according to an embodiment.

FIG. 2 is a flowchart illustrating an operation of an abnormality detection unit in the detection device of the present embodiment.

[Explanation of symbols]

Reference Signs List 10 battery, 12 current sensor, 22 first A / D converter, 26 first A / D converter, 28 CPU, 30 abnormality detector, 32 memory.

Claims (1)

[Claims] 1. A detecting means for detecting a physical quantity set to a predetermined reference value at a predetermined measuring position and outputting it as an electric signal, and a first conversion for converting the electric signal output from the detecting means to a digital signal Means, a second conversion means for converting the electric signal output from the detection means into a digital signal, the first conversion means, the reference output value after conversion in the second conversion means is stored in advance A reference output value storage means, connected to the outputs of the first and second conversion means, and comparing an output value output therefrom with a reference output value in the reference output value storage means, A detection device comprising: an abnormality detection unit configured to determine an abnormality from an abnormality of the detection unit and detect the abnormality.