JP2000298057A - Diagnosis method of seat load measuring device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a diagnosis method of a seat load measuring device for finding an abnormality of a seat load measuring device. SOLUTION: Outputs of load sensors 1 and 1L are input to a differential amplifier 4 via a multiplexer 3, and output from an A / D
The data is converted into a digital value by the converter 5 and input to the MPU 6. The offset adjustment amount is applied from the MPU 6 to the input of the differential amplifier 3 via the D / A converter 10. First, the output of the operational amplifier 4 is measured with no load applied to the seat, and the measured value is set to X1. Next, a predetermined load is applied to the seat, the output of the operational amplifier 3 is measured in that state, and the measured value is defined as Y1.
Then, it is determined whether or not the difference between Y1 and X1 is between predetermined A1 and B1. If the difference between Y1 and X1 is not between the predetermined values A1 and B1, an alarm output indicating an abnormality is issued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing the condition of a seat load measuring device for measuring a load applied to a seat, such as the weight of an occupant sitting on a seat in a passenger car or the like, and detecting an abnormality thereof. is there.

[0002]

2. Description of the Related Art Seat belts and airbags are installed as devices for ensuring the safety of occupants in passenger cars. Recently, in order to further improve these performances, attempts have been made to control the operation of these safety devices in accordance with the weight (weight) of the occupant. For example, in accordance with the weight of the occupant, the deployment gas amount and deployment speed of the airbag are adjusted, and the pretension of the seat belt is adjusted.

In order to perform such control, it is necessary to measure the weight of the occupant sitting on the seat. As an example of a method for measuring the weight of an occupant, load sensors (strain gauges) are arranged at the four corners of the bottom of the seat to determine the load applied to each corner, and these are summed to calculate the seat weight including the occupant's weight From the difference between the seat weight when the occupant is not on board and the seat weight when on board,
An apparatus for measuring the weight of an occupant has been proposed.

FIG. 7 shows an outline of an example of the apparatus. In FIG. 7, reference numerals 21 denote strain gauges installed at the four corners of the seat bottom, and a constant voltage is applied to each of the strain gauges 21 from a power supply device 22. When a load is applied to the strain gauge 21 and the resistance value of the resistance element forming the bridge changes, the balance of the bridge changes and a small voltage is generated from the strain gauge 21. This voltage is amplified by the differential amplifier 23 and output.

In practice, the outputs of the four differential amplifiers are input to a multiplexer 24, sequentially selected and converted into digital values by an A / D converter 25, and input to a microprocessor unit (MPU) 26. You. MPU26
Reads the output of each amplifier 23 sequentially, multiplies it by a conversion coefficient (sensitivity coefficient), converts it into a load value, and adds these to obtain the total seat load. Using the seat load, the control of the seat belt and the airbag as described above is performed inside the MPU 26 or output to the external output circuit 29 as necessary.

[0006] Each strain gauge 21 has an offset voltage. The offset voltage is a voltage generated when the load is zero, and its value differs depending on each strain gauge 21. Therefore, in order to measure an accurate load, it is necessary to compensate for the offset voltage. Further, since the strain gauge 21 measures the sum of the weight of the occupant and the weight of the seat, the weight of the seat must be subtracted in order to obtain the weight of the occupant. MPU
Reference numeral 26 has a function of performing these adjustments (tare adjustment).

That is, when a command signal is given from the external input signal circuit 28 in a state where no occupant is on the seat, the MPU 26 uses the weight value detected by each strain gauge 21 at that time as an unoccupied seat load. It is stored in the memory 27. In the figure, since four strain gauges 21 are used, four corresponding vacant seat load memories are prepared in the memory 27, and the vacant seat loads are stored therein. After that, the load calculated by subtracting the vacant load from the weight calculated from the output of each differential amplifier 23 is set as the load detected by each strain gauge 21. Then, the MPU 26 itself uses the sum of these as a load applied to the seat (for example, the weight of the occupant) for other controls, and outputs it to the outside as needed.

Strictly speaking, the output voltage of the strain gauges 21 generated by a unit load also varies among the strain gauges 21, so that the sensitivity needs to be corrected. Further, the sensitivity of the strain gauge may be different depending on the method of attaching the strain gauge, and therefore, the sensitivity may need to be corrected from this point as well. In this case, for example, the sensitivity coefficient of the strain gauge is calculated from the output difference of the differential amplifier 23 when the sheet is unloaded and when a predetermined load is applied to the sheet. The sensitivity can be corrected by multiplying the output of 23 by this sensitivity coefficient to calculate the load. This sensitivity coefficient is suitably stored in the memory 27.

[0009]

As described above,
As long as a commercially available metal strain gauge is used as the strain sensor, the circuit configuration as shown in FIG. 7 can accurately detect the load applied to the sheet. However, attaching a commercially available metal strain gauge to the sheet portion requires time and skill and has a problem in work efficiency. As a countermeasure, it has been considered that a strain gauge made of ceramic is formed integrally with a wiring circuit by using a printing technique on a member receiving a load of a sheet.

An example is shown in FIG. In FIG. 8, a seat 31 including a seat cushion 31a, a seat back 31b, a seat rail 31c, and a seat leg 31d is supported by a displacement member 32, and the displacement member 32 is supported by a seat support member by a bracket 33. . The displacement member 32 is made of steel, and on its surface, load sensors 35 and 36 and a printed wiring 37 are integrally formed by a printing technique. The load of the seat 31 is 31d.
The bending member 32 bends using the bracket 33 as a fulcrum and the seat leg 31d as a power point, and the displacement is detected by the load sensors 35 and 36. The displacement member 32 is provided on each of the left and right
And load sensors 35 and 36, respectively.
Thereby, the loads applied to the front and rear of the seat can be separately detected.

This method has a feature that the work process is simplified because the load sensors 35 and 36 and the printed wiring 37 are formed integrally by a printing technique. However, the characteristics of the load sensor manufactured by this method are different from those of commercially available metal strain gauges manufactured using microfabrication technology such as lithography, and the absolute value and offset value of the offset voltage vary greatly, and the sensitivity also varies. There is a weak point that there is.

Therefore, when an attempt is made to use a load sensor manufactured by this method in an apparatus having a circuit configuration as shown in FIG. 7, in an extreme case, the differential amplifier 23 is used due to the offset voltage of the load sensor. However, there is a problem that the output is saturated. When the output of the differential amplifier 23 is saturated, the zero point can no longer be corrected by the tare adjustment function of the MPU 26. Also, even before the output of the differential amplifier 23 is saturated,
If there is a large shift to one side (especially the plus side of the load),
As a result, the range of the load that can be measured is narrowed, and there is a problem that the weight of a certain amount or more cannot be measured due to the saturation of the differential amplifier 23. Further, since the circuit of FIG. 7 does not have a sensitivity adjustment mechanism, it has a problem that it is impossible to compensate for variations in sensitivity among load sensors.

That is, although the load sensor manufactured by the printing technique has excellent features in its own manufacturing process, the measurement accuracy is not sufficient.
Actually, it has a problem that it is difficult to use.

As a method for solving this problem, the present inventor has invented a seat load measuring device having a detection circuit configuration as shown in FIG. 1 and applied for a patent as Japanese Patent Application No. 294112/1998. In FIG. 1, 1R is a load sensor attached to the right displacement member 32, 1L is a load sensor attached to the left displacement member 32, a and b are front loads, and c and d are rear loads. The load is detected. A specified voltage is applied from the power supply 2 to the connection point between a and c, and the connection point between b and d is grounded. Therefore, the load applied to the front side of the sheet can be detected by detecting the voltage at the connection point between a and b, and the load applied to the rear side of the sheet can be detected by detecting the voltage at the connection point between c and d.

The voltage at the connection point between a and b, and the voltage at the connection point between c and d are input to the multiplexer 3, and one selected by the control of the microprocessor unit (MPU) 6 is the differential amplifier 4. Is input to Differential amplifier 4
Is converted into a digital value by the A / D converter 5 and input to the MPU 6. By switching the input of the multiplexer 3 and A / D converting and reading the output of the differential amplifier 4 at that time, the loads applied to the front, rear, left and right of the seat can be read separately. And the load applied to the entire sheet. Also, by taking these differences, the imbalance of the load can be known.

An area for storing an offset adjustment amount, an offset residual, and a sensitivity coefficient is assigned to the memory 7 attached to the MPU 6 for each load sensor. (Only the one corresponding to the input of No. 1 is shown in the figure.)
Are output to a D / A converter 10 to be converted into analog values, which are applied to the input of the differential amplifier 4.

When a tare adjustment command is input from the external input circuit 8, the MPU 7 sets an offset adjustment amount for each of the inputs No. 1 to No. 4 so that the output of the differential amplifier 4 falls within a predetermined range. Calculate and store in memory 7,
Output to the D / A converter 10. This value is converted into an analog value and input to the differential amplifier 4, so that the differential amplifier 4
Is a value close to a predetermined value. However, since the resolution of the D / A converter is limited, the value cannot be completely set to a predetermined value, and the value that cannot be compensated remains as the output of the differential amplifier 4. The output of the differential amplifier 4 that could not be compensated is stored in the memory 7 as an offset residual. The seat load measuring device shown in FIG. 1 is also provided with a function for adjusting the sensitivity of the load sensor described above.

At the time of load measurement, the multiplexer 3 is switched to output the output of the target load sensor to the differential amplifier 4.
Take in. At the same time, the offset adjustment amount corresponding to the load sensor is read out from the memory 7 and given to the differential amplifier 4 via the D / A converter 10, and this amount is subtracted.
Then, the four outputs of the differential amplifier corresponding to the difference are A / D
The data is converted into a digital value by the converter 5 and read into the MPU 6, the offset residual in the memory 7 is subtracted from this value, and the difference is multiplied by the sensitivity coefficient in the memory 7 to obtain a load value.

With such a circuit configuration, even when the load sensor has an offset voltage in a no-load state, the output of the differential amplifier 4 can be prevented from being saturated. However, in some cases, the sum of the weight of the sheet and the load applied to the sheet is determined by the load sensor 1.
The measurement range of R and 1L may be exceeded.
Even in this case, since the tare adjustment is performed, the output of the seat load measuring device is apparently within the measurement range. Therefore, there remains a problem that it is not known that the measured value exceeds the measurable range.

In addition, such a seat load measuring device includes:
May break down during use. For example, the load sensors 1R and 1L are disconnected, the differential amplifier 4 breaks down, and output fluctuation (drift or the like) occurs. Also, if the load sensors 1R and 1L and the seat are not properly attached, the load applied to the seat is correctly determined by the load sensors 1R and 1R.
There is also a problem due to a defective assembly that does not reach 1L. In these cases, the correct measurement of the seat load cannot be performed, and if the user does not know it, control for the safety of the airbag or the seat belt may be poor.

The present invention has been made in view of such circumstances, and a diagnostic method of a seat load measuring device for detecting an abnormality of a seat load measuring device including a seat load measuring device having a configuration as in the prior application has been proposed. The task is to provide.

[0022]

A first means for solving the above-mentioned problems is a seat load measuring device for measuring a load applied to a sheet, and a load for detecting the weight of the sheet and the weight of an object on the sheet. A method for diagnosing whether or not a sensor and an amplifier having an amplifier for amplifying a signal from a load sensor is normal. And comparing the information of the seat load measuring device with the information of the seat load measuring device in a state where the seat is placed on the load sensor, thereby diagnosing whether the seat load measuring device is normal or not. It is a diagnostic method of a measuring device (claim 1).

The parts are shipped from the part maker to the sheet maker with the left and right displacement members (members corresponding to 32 in FIG. 8) incorporating the load sensor incorporated in the sheet support member. Prior to this shipment, the load sensor is connected to a measurement circuit (as shown in FIG. 1) of the seat load measuring device in a state where no load is applied to the load sensor, and information from the seat load measuring device in that state is connected. Remember. When a sheet is mounted on a displacement member by a sheet maker, a load corresponding to the weight of the sheet is applied to the load sensor, so that information from the sheet load measuring device changes.

Since the amount of change in this information is predetermined in accordance with the load on the seat, if there is a change exceeding the amount that allows for an allowable error from the specified value, it is determined that the seat load measuring device is abnormal. Can be determined. The abnormal condition of the seat load measuring device includes not only a case where the measuring device itself is abnormal but also a case where the seat is poorly attached and an accurate load is not transmitted to the load sensor.
The information from the seat load measuring device is at least one of various state quantities related to the output of the load sensor, such as the measured load value, the tare adjustment amount (offset adjustment value), the output of the amplifier, and the like.

When a plurality of load sensors are used to measure the load on the seat, an abnormality may be diagnosed for each load sensor, or some of them may be diagnosed (for example, An abnormality may be diagnosed for the output of the sum of the load sensors). This is the same for all the claimed inventions in this specification.

A second means for solving the above-mentioned problem is:
A seat load measuring device for measuring a load applied to a sheet, comprising a load sensor for detecting the weight of the sheet and the weight of an object on the sheet, and an amplifier for amplifying a signal from the load sensor. It is a method of diagnosing whether or not the possession is normal, by comparing information from the seat load measurement unit corresponding to each load sensor when the load sensor is incorporated in the seat unit, A diagnostic method for a seat load measuring device, which diagnoses whether the seat load measuring device is normal (claim 2).

According to this means, the information from the seat load measuring section corresponding to each load sensor when the load sensor is incorporated in the seat section is compared. If the difference is equal to or larger than the specified value or equal to or smaller than the specified value, it is determined that the load sensor is not properly incorporated in the seat portion or that the load sensor itself has become abnormal. Therefore, abnormality of the load sensor can be detected. In addition, as shown in FIG. 1, when the sheet measurement unit corresponding to each load sensor is common, the determination is performed assuming that the common part is provided separately for each sensor. For example, for each load sensor, A
The values obtained from the / D converter are compared with each other. Here, the sheet portion is a portion on which the sheet is placed, and corresponds to the bracket 33 or the sheet support member in FIG.

A third means for solving the above-mentioned problem is:
A seat load measuring device for measuring a load applied to a seat, comprising a load sensor for detecting the weight of the seat and the weight of an object on the seat, and an amplifier for amplifying a signal from the load sensor. A method of diagnosing whether or not there is, a seat is placed on a load sensor, and information from a seat load measuring device before being incorporated into a vehicle body and information from a seat load measuring device in a state of being incorporated into a vehicle body are obtained. A diagnosis method for a seat load measuring device (claim 3), characterized in that a comparison is made to determine whether or not the seat load measuring device is normal.

The information from the seat load measuring device should not change significantly before and after the seat unit having the seat mounted on the load sensor is incorporated into the vehicle body. Therefore, when this information changes to a value equal to or more than the allowable value, it is determined that the load sensor is not properly incorporated or that the load sensor itself has become abnormal. Therefore, abnormality of the load sensor can be detected.

A fourth means for solving the above-mentioned problem is:
A seat load measuring device for measuring a load applied to a sheet, comprising a load sensor for detecting the weight of the sheet and the weight of an object on the sheet, and an amplifier for amplifying a signal from the load sensor. This is a method of diagnosing whether or not what you have is normal.Comparing information from the seat load measurement unit corresponding to each load sensor when the seat unit with the load sensor is installed in the vehicle body Accordingly, a diagnosis method of the seat load measuring device is characterized in that it is diagnosed whether or not the seat load measuring device is normal (claim 4).

According to this means, the information from the seat load measuring section corresponding to each load sensor when the seat section is installed in the vehicle body is compared. If the difference is equal to or greater than the specified value, or equal to or less than the specified value,
It is determined that the load sensor itself has become abnormal while the seat portion is not properly assembled. Therefore, abnormality of the load sensor can be detected. In addition, as shown in FIG. 1, when the sheet measurement unit corresponding to each load sensor is common, the determination is performed assuming that the common part is provided separately for each sensor. For example, each,
The values obtained from the A / D converter are compared with each other corresponding to the load sensor.

A fifth means for solving the above problem is as follows.
A seat load measuring device for measuring a load applied to a seat, comprising a load sensor for detecting the weight of the seat and the weight of an object on the seat, and an amplifier for amplifying a signal from the load sensor. A method for diagnosing whether or not there is a load, wherein information from the seat load measuring device when no load is applied to the load sensor and information from the seat load measuring device when a predetermined load is applied to the load sensor. A diagnosis method for a seat load measuring device (claim 5), characterized in that a comparison is made to determine whether or not the seat load measuring device is normal.

In this means, for example, before the shipment from the parts maker to the sheet maker described in the description of the first means, the left and right displacement members (with the load sensors) are incorporated into the sheet support member. In this state, the information from the seat load measuring device when no load is applied to the load sensor is compared with the information from the seat load measuring device when a predetermined load is applied to the load sensor. If the sensitivity is not within the range of the reference value, it can be determined that the seat load measuring device is abnormal.

A sixth means for solving the above-mentioned problem is:
A seat load measuring device for measuring a load applied to a seat, comprising a load sensor for detecting the weight of the seat and the weight of an object on the seat, and an amplifier for amplifying a signal from the load sensor. A method for diagnosing whether or not there is, wherein information from a seat load measuring device in a state where a load is not applied to a seat is compared with information from a seat load measuring device when a predetermined load is applied to a seat. Accordingly, there is provided a method of diagnosing a seat load measuring device, which diagnoses whether or not the seat load measuring device is normal (claim 6).

In this means, information from the seat load measuring device when no load is applied to the seat is compared with information from the seat load measuring device when a predetermined load is applied to the seat. If the difference between these pieces of information is out of the predetermined range, the seat load measuring device determines that there is an abnormality. This inspection may be performed before the seat is installed in the vehicle body, or may be performed after the seat is installed in the vehicle body.

A seventh means for solving the above-mentioned problem is as follows.
A seat load measuring device for measuring a load applied to a seat, comprising a load sensor for detecting the weight of the seat and the weight of an object on the seat, and an amplifier for amplifying a signal from the load sensor. A method of diagnosing whether or not there is, by comparing the sensitivity of the sheet load measuring device before placing the sheet on the load sensor and the sensitivity of the sheet load measuring device after placing the sheet on the load sensor, A diagnosis method for a seat load measuring device, which diagnoses whether or not the seat load measuring device is normal (claim 7).

According to this means, the sensitivity of the seat load measuring device before and after the seat is mounted is compared. If the seat load measuring device is normal, these differences should be within the specified value, so if the difference is out of the specified value,
It can be determined that the seat load measuring device is abnormal. In addition,
This inspection may be performed before the seat is installed in the vehicle body, or may be performed after the seat is installed in the vehicle body.

Eighth means for solving the above-mentioned problem is:
Any one of the first to seventh means, wherein at least the output of the amplifier is used as information from the seat load measuring device (claim 8).

Since the output of the amplifier directly represents the load, by comparing these values, it is possible to easily and accurately detect an abnormality in the seat load measuring device. For example, when the difference between the output of the amplifier when a constant load is applied to the sheet and when it is not applied, or the difference between the output of the amplifier when the sheet is placed on the load sensor and when it is not placed is not within the predetermined range, It can be determined that there is some abnormality in the seat load measuring device. The output of the amplifier includes not only the output of the amplifier itself but also those of A
Needless to say, it also includes the value obtained by the / D conversion.

A ninth means for solving the above problems is as follows:
Any of the first to eighth means, wherein the seat load measuring device has a tare adjusting unit, and at least information from the seat load measuring device includes:
The output of the tare adjusting unit when the tare adjusting unit is operated in each of the states is used (claim 9).

The tare adjusting section has a function of controlling the output of the amplifier in a certain state to a predetermined value, or of storing the output of the amplifier in a certain state and subtracting it from the subsequent output. The output value (for example, the offset adjustment amount and the offset residual) is equivalent to the output of the amplifier in the ninth means. Therefore, also in this means, by comparing these values, it is possible to easily and accurately detect an abnormality of the seat load measuring device.

A tenth means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting the weight of the seat and the weight of an object on the sheet; An amplifier that amplifies the signal of, and a method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a tare adjusting unit is normal, in a state where a sheet is placed on a load sensor. After performing the initial tare adjustment, the adjustment amount is stored as the initial adjustment amount, and thereafter, each time the tare adjustment is performed, the adjustment amount at that time is compared with the initial adjustment amount, so that the seat load measuring device is normal. A method of diagnosing a seat load measuring device, characterized by diagnosing whether or not there is a vehicle (claim 10).

Even if the seat load measuring device is normal at the beginning, it may break down or its performance may change during use due to various causes. In order to detect these changes during use, the adjustment amount (the offset adjustment amount, the offset residual error, etc.) in the first tare adjustment is stored as the initial adjustment amount. Thereafter, each time the tare adjustment is performed, the adjustment amount is compared with the initial adjustment amount. For example, when the difference between the two becomes a predetermined value or more, it can be determined that a failure or abnormality has occurred. The tare adjustment performed with the seat mounted on the load sensor may be performed before the seat is mounted on the vehicle body, or may be performed with the seat mounted on the vehicle body. The tare adjustment performed later may be in a state where the sheet is placed or in a state where the sheet is not placed.

An eleventh means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a sheet, comprising: a load sensor for detecting the weight of the sheet and the weight of an object on the sheet; An amplifier that amplifies the signal of, and a diagnostic method of a seat load measuring device for diagnosing whether or not the measurement value of a device having a tare adjusting unit is normal, in a state where the sheet is not placed on the load sensor. After performing the initial tare adjustment, the adjustment amount is stored as the initial adjustment amount, and thereafter, each time the tare adjustment is performed, the adjustment amount at that time is compared with the initial adjustment amount, so that the seat load measuring device is normal. A method of diagnosing a seat load measuring device, characterized by diagnosing whether or not there is a vehicle (claim 11).

In this means, unlike the tenth means, an adjustment amount obtained by performing an initial tare adjustment in a state where no sheet is placed on the load sensor is used as the initial adjustment amount. Therefore, the same effect as the tenth means is obtained. In addition,
The tare adjustment performed later may be a state where a sheet is placed or a state where a sheet is not placed.

A twelfth means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a sheet, comprising: a load sensor for detecting the weight of the sheet and the weight of an object on the sheet; An amplifier that amplifies the signal of, and a method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a tare adjusting unit is normal, in a state where a sheet is placed on a load sensor. Tare adjustment is performed, the output of the seat load measuring device at that time is stored as an initial value, and thereafter, the output of the seat load measuring device is measured in a state where no object is mounted on the seat,
By comparing that measurement with the stored initial value,
A diagnosis method for a seat load measuring device, comprising: diagnosing whether the seat load measuring device is normal.
2).

In this means, the output of the seat load measuring device when the tare adjustment is performed is stored as an initial value,
Thereafter, the output of the seat load measuring device is measured while no object is mounted on the seat, and the measured value is compared with the stored initial value. If the seat load measurement system is normal, the change in the output of the amplifier should be within a predetermined range. Therefore, when this is out of the predetermined range, it is determined that an abnormality has occurred. According to this means, it is possible to detect a temporal change of the seat load measuring device.

A thirteenth means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a sheet, comprising: a load sensor for detecting the weight of the sheet and the weight of an object on the sheet; An amplifier that amplifies the signal of, and a diagnostic method of a seat load measuring device for diagnosing whether or not the measurement value of a device having a tare adjusting unit is normal, in a state where the sheet is not placed on the load sensor. A tare adjustment is performed, the adjustment amount is stored as a first adjustment amount A, and the tare adjustment is performed again with the sheet placed on the load sensor, and the adjustment amount is stored as a second adjustment amount B. Thereafter, measurement of the load applied to the seat is performed using these two adjustment amounts, and the output of the load measuring device is output using the adjustment amount B, and the adjustment amount A is used. If measurements were performed exceeds a predetermined value, it is possible to perform the warning output, and the diagnostic methods of the seat load measuring apparatus which is characterized in that at least one of carrying out the correction calculation (Claim 13).

The final sheet load is output as a load obtained by performing a tare adjustment with the sheet placed on the load sensor and subtracting the tare amount. However, there is a possibility that the load applied to the load sensor during the load measurement may exceed the measurable range of the load sensor due to the weight of the sheet being too heavy or the mounting method having some abnormality. In this means, when the measurement value performed using the first adjustment amount A exceeds a predetermined value, it is determined that the load exceeds the measurable range of the load sensor, and an alarm is output, or At least one of a correction operation and a correction operation is performed using a correction value determined by measurement. Therefore, there is no possibility of erroneous determination by making a determination using a measured value exceeding the measurable range.

A fourteenth means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting the weight of the seat and the weight of an object on the sheet; An amplifier that amplifies the signal of, and a diagnostic method of a seat load measuring device for diagnosing whether or not the measurement value of a device having a tare adjusting unit is normal, in a state where the sheet is not placed on the load sensor. Tare adjustment is performed by applying a predetermined load to the load sensor, and the adjustment amount is stored as a first adjustment amount C. Thereafter, the tare adjustment is performed with the sheet placed on the load sensor, and the adjustment amount is set to the first adjustment amount. 2, and thereafter, the load applied to the seat was measured using these two adjustment amounts, and the output of the load measuring device was measured using the adjustment amount D. Outputs, when the measurement value was performed using the adjustment amount C exceeds a predetermined value, performing the alarm output,
And performing at least one of a correction calculation and a diagnosis method of the seat load measuring device.
4).

Depending on the configuration of the seat load measuring device, the resolution of the amplifier may be increased by making the measurement range of the amplifier smaller than the measurement range of the load sensor. For example, there may be a case where the measurement range of the load sensor is 200 kgf and the measurement range of the amplifier is 50 kgf.
In such a case, the total load on the load sensor is 200kgf
May not be known only by looking at the output of the amplifier. Therefore, in this means,
In addition to the normal tare adjustment amount D, the tare adjustment is performed with a load of, for example, 180 kgf applied to the load sensor before the sheet is placed, and the tare adjustment amount C is stored (if necessary, at that time). The output of the amplifier is stored).

Thereafter, measurement is periodically performed using the tare adjustment amount C, and the measured value at that time is measured. For example, if the measurement value when the tare adjustment is performed with a load of 180 kgf applied to the load sensor is 0, and if 30 kgf is measured in the subsequent measurement, the output of the load sensor is 210
Since it is kgf and exceeds the measurement range, an alarm is output or a correction operation is performed. As described above, according to the present means, even when the range of the amplifier is narrower than the measurement range of the load sensor, overrange of the load sensor can be detected.

A fifteenth means for solving the above-mentioned problem is a seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting the weight of the seat and the weight of an object on the seat; A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of an amplifier having a sensitivity adjustment unit of a load sensor and an amplifier for amplifying a signal of the load sensor is normal. A method of diagnosing the seat load measuring device, characterized by diagnosing whether or not the seat load measuring device is normal by comparing with a sensitivity adjustment value at the time of performing the sensitivity adjustment. 15).

In the present means, the sensitivity adjustment value performed at the initial stage is stored, and thereafter, the change with time of the sensitivity of the seat load measuring device is detected by comparing the sensitivity adjustment value when the sensitivity adjustment is performed. can do. As the initial sensitivity adjustment value, it is preferable to use a sensitivity adjustment value performed before shipment from a component manufacturer, that is, a sensitivity adjustment value performed before mounting a sheet.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A seat load measuring device is assembled to a vehicle body through the following steps. First, the left and right displacement members incorporating the load sensor (32 in FIG. 8)
Are shipped from the component maker to the sheet maker in a state in which the member corresponding to (i) is incorporated in the seat support member. At this time, the load sensor is connected to a measurement circuit as shown in FIG. 1 in a state where the left and right displacement members are incorporated in the seat support member, and the tare adjustment is performed. The resulting offset adjustment amounts and offset residuals corresponding to the four front-rear, left-right, and four-point loads are used as factory default data as MP
It is stored in the memory in U.

After completion of the tare adjustment, a predetermined load is individually applied to the front, rear, left and right displacement members. Then, the values of the A / D converters corresponding to the inputs No. 1 to No. 4 in FIG. 1 are read, and the sensitivity coefficients of the four front, rear, left and right load sensors are obtained from these values. The data is stored in the memory in the MPU, and at the same time, the load is obtained using the sensitivity coefficient.

The displacement member 32 shown in FIG. 8 is often provided with a mechanical stopper (not shown) so as not to be damaged when an abnormal load is applied. In this case, the load at which the displacement member 32 contacts the stopper is
It is obtained for each load sensor and stored in the MPU. This load is used as the maximum measurable load. If the differential amplifier 4 is saturated before the displacement member comes into contact with the stopper, the offset adjustment amount used for the tare adjustment is moved to shift the zero point of the differential amplifier 4, and the saturation of the differential amplifier 4 is reduced. A load is further applied in the released state, and the load at which the displacement member 32 contacts the stopper is measured. In this case, the sum of the measured load and the load corresponding to the amount by which the zero point of the differential amplifier 4 is shifted is the displacement member 32.
Is the load that comes into contact with the stopper, and this value or the amount of deviation between the measured load and the zero point of the differential amplifier 4 is expressed as MP
Store in U.

As described above, the seat load measuring device
The product is shipped to a sheet manufacturer in a state where the tare adjustment and the sensitivity adjustment have been performed, and information such as a measurement range is recorded.

The seat maker incorporates the seat on the seat load measuring device. At the time when the seat is completely assembled, the output of the seat load measuring device is checked to check whether the seat is correctly assembled and whether the seat load measuring device is damaged. First, the output (total weight) of the seat load measuring device is checked, and it is checked whether or not this approximately matches a predetermined value determined by the weight of the seat. If these differences are greater than or equal to the allowable value, the assembly is abnormal or
Either the seat load measuring device is abnormal.

Next, the loads detected by the front, rear, left and right load sensors are checked, and it is checked whether or not the difference is within a predetermined range. When the seat load measuring device is incorporated in the seat, the weight of the seat is distributed to four load sensors. However, if the seat is deformed or improperly incorporated into the seat, the seat load will not be properly distributed to the four load sensors, and even if the total weight is normal, individual loads will fluctuate greatly and the load balance will be lost. The output of each load sensor is compared with the initial data recorded in the memory, and it is checked whether these differences are within a predetermined range.

The outputs of the load sensors may be compared with each other to check whether these differences are within a predetermined range. The output of each of the four load sensors is 2
It is also possible to calculate the total value of each location and check whether the difference is within a predetermined range. Further, the position of the center of gravity of the sheet may be calculated from the outputs of the four load sensors, and it may be checked whether the position is within a predetermined range. If it is not within the predetermined range, it means that either the assembly is abnormal or the seat load measuring device is abnormal.

When the above test is normal, the weight and the total weight detected by each load sensor are stored in the MPU. If necessary, after assembling the sheet, apply a predetermined load on the sheet, and only the weight corresponding to the applied load,
A test of load cell sensitivity is performed by making sure that the load detected by the seat load measuring device increases.

At the automobile manufacturer, after installing the seat in the vehicle body, the same test as the test performed by the seat manufacturer is performed. That is, the check of the total weight of the seat and the check of the balance of the detected load of each weight sensor.
Then, when these tests are normal, the weight and the total weight detected by each load sensor are stored in the MPU as initial data of shipment from the car maker.

If necessary, after incorporating the sheet,
A load test is performed by applying a predetermined load to the seat and confirming that the load detected by the seat load measuring device increases by a weight corresponding to the applied load.

As a result of the above test, it is confirmed that the seat is incorporated and the seat load measuring device is normal. After that, the tare adjustment is performed with the seat mounted, and the offset adjustment amount and the offset residual in this case are determined. The data is stored in the MPU as initial data upon shipment from the manufacturer. Subsequent measurement of seat load
Unless the tare adjustment is performed again, the adjustment is performed based on the initial data at the time of shipment from the manufacturer.

As described in the section of the means for solving the problems, the diagnosis of the abnormality may be performed for each load sensor, or may be a group of some (for example, the output of the sum of all the load sensors). May be performed. Therefore, in order to reduce the storage memory of the MPU, the tare adjustment may not be performed by each load sensor, but may be performed on the output of the sum of all the load sensors and recorded as initial data. Further, the maximum load (measurement range) that can be measured may be recorded as an output of a sum of some of the load sensors, and an abnormality diagnosis may be performed based on the recorded data.

After the vehicle is shipped from the factory, a zero check of the seat load is periodically performed. This is because when it is clear that there is no load on the seat, for example, when the seat belt is released and the engine key is removed, the output (total weight) of the seat load measuring device increases from zero. It checks whether there is any deviation and whether the balance of the output of each load sensor has been lost. If any of the above occurs, an alarm is issued. The zero point check may be performed by a human using a push button switch or the like.

Even when it is not clear that there is no load on the seat, if the measurement result (gross weight) of the seat load is close to zero, at least the initial data at the time of shipment from the factory or the initial data at the time of shipment from the manufacturer. Based on one of them, it is also possible to check whether each measured load value does not exceed a predetermined value or whether the balance of each load has been lost, and if there is an abnormality, an alarm will be issued You can also. Further, an alarm can be issued even when the measurement result (total weight) of the seat load is stably measured to be a minus load (opposite to gravity). Regardless of the value of the seat load measurement result (gross weight), check whether the load applied to each load sensor does not exceed the measurable large load. Interruption,
The possibility of erroneous determination can be eliminated by changing the procedure of the calculation processing, such as holding the previous load value and executing the correction calculation.

If the above-mentioned measurement range continues for a certain period of time or occurs frequently, it can be diagnosed as abnormal and an alarm can be issued. Overrange of the measurement range is also caused by abnormality of the seat and the seat load measuring device, but can also occur when the weight of the occupant sitting on the seat is heavy. Therefore, the determination value of the alarm may be changed according to the measurement result (total weight) of the seat load.

Further, the tare adjustment may be performed automatically or manually as required. This is because when it is clear that there is no load on the seat, for example, when the seat belt is opened and the engine key is removed, or when the push button switch is pressed, the tare adjustment is performed again. Things. At this time, the tare adjustment amount (offset adjustment amount, offset residual error, etc.) is stored in the MPU and used for history management or used for abnormality diagnosis by comparing with initial data at the time of shipment from the manufacturer. You.

Hereinafter, examples of the embodiment of the present invention performed in each of the above steps will be described with reference to flowcharts. The following determination process does not specify the number of sensors incorporated in the sheet, and the number of sensors may be, for example, four or two. Also, the sum of a plurality of sensor outputs may be used for processing. The seat load measuring device that is the object of the diagnostic method is shown in FIG.
It is assumed that

FIG. 2 is a flowchart showing a diagnostic method according to a first embodiment of the present invention. This flow is started by a command from the external input circuit 8. First, in step S11, the output of the differential amplifier 4 (the value of the A / D converter 5) is measured in a state where no load is applied to the sheet (the state in which the sheet is not loaded), and the measured value is defined as X1. Next, in step S12, a predetermined load is applied to the seat, the output of the operational amplifier 4 is measured in that state, and the measured value is set to Y1. Then, in step S13, Y1
It is determined whether or not the difference between X1 and X1 is between predetermined A1 and B1, that is, whether A1 ≦ Y1−X1 ≦ B1. If the difference between Y1 and X1 is not between the predetermined values A1 and B1, an alarm output indicating an abnormality is issued in step S14. Although omitted in the flowchart,
This operation is performed for all load sensor outputs No. 1 to No. 4.

According to this method, in particular, whether the sensitivity of each load sensor in the seat mounted state is within a normal value, whether the load sensitivity of the entire seat is a normal value, and whether the seat mounted state is normal. You can check if it is.

Further, instead of the operation of S11, a state where no sheet is loaded on the load sensor 1 (a state where no sheet is loaded).
The measured value of the differential amplifier 4 in the above may be set to X1, and instead of the operation of S12, the measured value of the differential amplifier 4 with the sheet loaded on the load sensor 1 may be set to Y1. In this case, the load on the seat corresponds to the predetermined load.

FIG. 3 is a flowchart showing a diagnostic method according to a second embodiment of the present invention. This flow is started by a command from the external input circuit 8. First, in step S21, a tare adjustment is performed in a state where a sheet is not stacked on the load sensor 1, and the tare adjustment amount is set to X2.
And The tare adjustment amount is, for example, an amount added to the differential amplifier in order to set the output of the differential amplifier 3 to a predetermined value, such as an offset adjustment amount and an offset residual in FIG.

Next, in step S22, the tare adjustment is performed again with the sheets stacked, and the tare adjustment amount is set to Y.
Let it be 2. Then, in step S23, whether the difference between Y1 and X1 is between predetermined A2 and B2,
It is determined whether or not ≤Y2-X2≤B2. If the difference between Y2 and X2 is not between the predetermined values A2 and B2, an alarm output indicating an abnormality is issued in step S24. Although not shown in the flowchart, this operation is performed for all load sensors.

According to this method, in particular, it can be checked whether the sensitivity of each load sensor is within a normal value, and whether the seat mounting state is normal.

After the sheet is loaded on the load sensor, tare adjustment is performed without applying a load to the sheet instead of the operation of step S21, and a predetermined load is applied to the sheet instead of the operation of step S22. The tare adjustment may be performed in a state where the tare is adjusted.

FIG. 4 is a flowchart showing a diagnostic method according to a third embodiment of the present invention. This flow is started by a command from the external input circuit 8. First, in step S31, sensitivity adjustment is performed with no sheets loaded, and the obtained sensitivity coefficient is set to X3. In the sensitivity adjustment, a difference ΔV between the output of the differential amplifier 3 when no load is applied and the output of the differential amplifier 3 when a predetermined load W is applied is obtained, for example, as k = W / ΔV. . Next, in step S32, sensitivity adjustment is performed while the sheets are stacked, and the obtained sensitivity coefficient is set to Y3. And
In step S33, it is determined whether the difference between Y3 and X3 is within a predetermined value A3, that is, whether | Y3-X3 | ≦ A3. Then, if the difference between Y3 and X3 is not within the predetermined value A3, an alarm output indicating an abnormality is issued in step S34. Although not shown in the flowchart, this operation is performed for all load sensors.
With this method, it is possible to particularly check whether the seat mounting state is normal.

FIG. 5 is a flowchart showing a diagnostic method according to a fourth embodiment of the present invention. (A) shows the work performed before the car is sold,
(B) shows the work performed after the car is sold.
At the time of assembling the vehicle, an initial tare adjustment is carried out in a no-load state of the seat in step S41 according to a command from the external input signal circuit 8, and the tare adjustment amount X4 is stored.

After the car is sold, a tare adjustment is performed in a state where the seat is not loaded in step S42 according to a tare adjustment command at a vehicle inspection factory or the like, and a tare adjustment amount Y4 is obtained. Then, in a step S43, whether or not the difference between X4 and Y4 is within a predetermined value A4, that is, | Y4-X4 |
It is determined whether .ltoreq.A4. And Y4 and X4
If the difference is not within the predetermined value A4, an alarm output indicating an abnormality is issued in step S44. Although not shown in the flowchart, this operation is performed for all load sensors. With this method, it is possible to detect, in particular, a failure of the seat load measuring device, a change in characteristics over time, a mounting failure at the time of seat replacement, and the like.

FIG. 6 is a flowchart showing a diagnostic method according to a fifth embodiment of the present invention. (A) is a work performed before the car is sold,
(B) shows the work performed after the car is sold.
At the time of assembling the vehicle, an initial tare adjustment is performed in a state where no sheets are loaded in step S51 in accordance with a command from the external input signal circuit 8, and the tare adjustment amount A is stored. Next, in step S52, the initial tare adjustment is performed in the sheet stacked state, and the tare adjustment amount B is stored.

When measuring the seat load after the car is sold, first, in step S53, the tare adjustment amount A
Is used to perform load measurement, and the measured load value at that time is defined as X5. Subsequently, in step S54, load measurement is performed using the tare adjustment amount B, and the measured value is set to Y5. Then, in a step S55, it is determined whether or not X5 exceeds a predetermined value A5. If so, it is determined that the measured value is out of the measurement range of the load sensor 1 and an alarm is issued in step S57 to notify a human that the measured value is not reliable. Then, in step S58, the measured value Y5 is corrected using a correction value determined in advance by measurement, and is used as a load measured value. If X5 does not exceed the predetermined value A5, it is determined that the value is normal, and the process proceeds to step S56, which is a normal routine, and various controls are performed using Y5 as a load measurement value.

In the above description, the first embodiment,
Although the second, third, and fourth embodiments have been described as being performed in an automatic sequence, all or some of them may be performed manually. At this time, when a person makes a determination of an abnormality, if a person can make the above determination, an alarm output is not necessary. In addition, the fifth
In the embodiment, the sequence (A) may be performed manually.

In the case where the seat load measuring device adjusts the sensitivity of the load sensor by using a power supply voltage provided for each load sensor, the seat load measuring device according to the first and second aspects of the present invention. This power supply voltage can be used as the information from. In the above description, the information for judging the abnormality is described one by one. However, the abnormality may be judged by combining two or more pieces of such information.

[0086]

As described above, according to the first aspect of the present invention, the information from the sheet load measuring device in a state where the sheet is not placed on the load sensor and the sheet is placed on the load sensor. Since the information is compared with the information from the seat load measuring device in the mounted state, an abnormality of the seat load measuring device can be detected.

According to the second aspect of the present invention, since the information from the seat load measuring section corresponding to each load sensor when the load sensor is incorporated in the seat portion is compared, the abnormality of the seat load measuring device can be determined. Can be detected.

According to the third aspect of the present invention, the information from the seat load measuring device before the seat is mounted on the load sensor and incorporated in the vehicle body and the information from the seat load measuring device in a state where the seat is incorporated in the vehicle body are exchanged. Since the comparison is made, an abnormality of the seat load measuring device can be detected.

In the invention according to claim 4, since the information from the seat load measuring units corresponding to the respective load sensors when the seat unit incorporating the load sensor is incorporated into the vehicle body is compared, the seat load measurement is performed. An abnormality of the device can be detected.

In the invention according to claim 5, the information from the seat load measuring device when no load is applied to the load sensor and the information from the seat load measuring device when a predetermined load is applied to the load sensor. Since we are comparing
An abnormality of the seat load measuring device can be detected.

In the invention according to claim 6, information from the seat load measuring device when no load is applied to the seat is compared with information from the seat load measuring device when a predetermined load is applied to the seat. Therefore, an abnormality of the seat load measuring device can be detected.

In the invention according to claim 7, the sensitivity of the sheet load measuring device before placing the sheet on the load sensor is compared with the sensitivity of the sheet load measuring device after placing the sheet on the load sensor. Thus, an abnormality of the seat load measuring device can be detected.

In the invention according to claim 8, since at least the output of the amplifier is used as the information from the seat load measuring device, it is possible to accurately diagnose the abnormality.

In the ninth aspect of the present invention, at least the output of the tare adjusting unit when the tare adjusting unit is operated is used as the information from the load measuring device.
An abnormality can be diagnosed accurately.

In the invention according to the tenth aspect, the initial tare adjustment is performed while the sheet is placed on the load sensor.
The adjustment amount is stored as an initial adjustment amount, and thereafter, each time the tare adjustment is performed, the adjustment amount at that time is compared with the initial adjustment amount, so that a change with time of the seat load measuring device can be detected. .

According to the eleventh aspect of the present invention, the initial tare adjustment is performed in a state where the sheet is not placed on the load sensor, and the adjustment amount is stored as the initial adjustment amount. Since the adjustment amount at that time is compared with the initial adjustment amount, it is possible to detect a change with time of the seat load measuring device as in the invention according to claim 10.

According to the twelfth aspect of the present invention, the tare adjustment is performed with the sheet placed on the load sensor, and the output of the sheet load measuring device at that time is stored as an initial value. The output of the seat load measuring device is measured in a state where the seat load measuring device is not mounted, and the measured value is compared with a stored initial value.
As in the invention according to the first aspect, it is possible to detect a change with time of the seat load measuring device.

According to the thirteenth aspect of the present invention, the load measured using the tare adjustment value obtained without placing the sheet on the load sensor is used for monitoring the output of the load sensor. Over can be detected.

According to the fourteenth aspect of the present invention, the load measured using the air volume adjustment amount when a predetermined load is applied to the sheet and the tare adjustment is performed is used for monitoring the output of the load sensor. Overrange of the load sensor can be detected.

In the invention according to the fifteenth aspect, the sensitivity adjustment value performed at the beginning is stored, and then compared with the sensitivity adjustment value at the time of performing the sensitivity adjustment. Can be detected over time.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a seat load measuring device invented by the present inventors.

FIG. 2 is a flowchart illustrating a diagnostic method that is a first example of an embodiment of the present invention.

FIG. 3 is a flowchart illustrating a diagnostic method according to a second example of the embodiment of the present invention;

FIG. 4 is a flowchart illustrating a diagnosis method that is a third example of the embodiment of the present invention.

FIG. 5 is a flowchart illustrating a diagnostic method that is a fourth example of the embodiment of the present invention.

FIG. 6 is a flowchart illustrating a diagnostic method that is a fifth example of the embodiment of the present invention.

FIG. 7 is a schematic configuration diagram showing an example of a conventional seat load measuring device.

FIG. 8 is a diagram illustrating an example of a method of attaching a seat load sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Load sensor 2 ... Power supply device 3 ... Multiplexer 4 ... Operation amplifier 5 ... A / D converter 6 ... Microprocessor unit (MPU) 7 ... Memory 8 ... External input circuit 9 ... External output circuit 10 ... D / A conversion vessel

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B60N 2/44 B60N 2/44

Claims (15)

[Claims] A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. A method of diagnosing whether or not the normal is normal, information from the sheet load measuring device in a state where the sheet is not placed on the load sensor,
Diagnosis of the seat load measuring device characterized by diagnosing whether or not the seat load measuring device is normal by comparing information from the seat load measuring device in a state where the seat is placed on the load sensor. Method. 2. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. This is a method for diagnosing whether or not a plurality of seats are normal, wherein information from a seat load measuring unit corresponding to each load sensor when the load sensor is incorporated in the seat unit. A method for diagnosing a seat load measuring device, comprising: diagnosing whether the seat load measuring device is normal by comparing. 3. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. This is a method of diagnosing whether or not the normal condition is normal. The information is received from the seat load measuring device before the seat is mounted on the load sensor and incorporated into the vehicle body, and the seat load measuring device in a state where the seat is incorporated into the vehicle body. A method for diagnosing a seat load measuring device, comprising diagnosing whether or not a seat load measuring device is normal by comparing information from a seat load measuring device. 4. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and an object on the seat; and an amplifier for amplifying a signal from the load sensor. A method for diagnosing whether or not a plurality of seats are normal, wherein a seat load measuring unit corresponding to each load sensor when the seat unit incorporating the load sensor is incorporated into a vehicle body. A diagnostic method for a seat load measuring device, characterized in that whether or not the seat load measuring device is normal is determined by comparing information from the seat load measuring device. 5. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. This is a method of diagnosing whether the load sensor is normal or not, the information from the seat load measuring device when no load is applied to the load sensor, and the seat load measuring device when a predetermined load is applied to the load sensor. A method for diagnosing a seat load measuring device, comprising diagnosing whether or not a seat load measuring device is normal by comparing information from a seat load measuring device. 6. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. A method for diagnosing whether or not a normal load is applied to the seat, the information from the seat load measuring device when no load is applied to the seat, and the information from the seat load measuring device when a predetermined load is applied to the seat. A method for diagnosing a seat load measuring device, comprising diagnosing whether or not the seat load measuring device is normal by comparing the information with information. 7. A seat load measuring device for measuring a load applied to a seat, comprising: a load sensor for detecting a weight of the seat and a weight of an object on the seat; and an amplifier for amplifying a signal from the load sensor. This is a method of diagnosing whether or not the load sensor is normal, and the sensitivity of the sheet load measuring device before placing the sheet on the load sensor and the sensitivity of the sheet load measuring device after placing the sheet on the load sensor. A method for diagnosing a seat load measuring device, comprising: diagnosing whether the seat load measuring device is normal by comparing. 8. One of claims 1 to 7
The diagnostic method for a seat load measuring device according to any one of the preceding claims, wherein at least an output of the amplifier is used as information from the seat load measuring device. 9. One of claims 1 to 8
It is a diagnostic method of the seat load measuring device according to the paragraph, wherein the seat load measuring device has a tare adjustment unit, at least as information from the seat load measuring device,
A method for diagnosing a load measuring device, comprising using an output of a tare adjusting unit when a tare adjusting unit is operated in each of the states. 10. A seat load measuring device for measuring a load applied to a seat, a load sensor for detecting a weight of the seat and an object on the seat, an amplifier for amplifying a signal from the load sensor, and a tare adjusting unit. A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a normal value is provided, wherein an initial tare adjustment is performed in a state where a sheet is placed on a load sensor, and the adjustment amount is determined. It is stored as an initial adjustment amount, and thereafter, each time the tare adjustment is performed, the adjustment amount at that time is compared with the initial adjustment amount, thereby diagnosing whether the seat load measuring device is normal or not. Diagnostic method of the seat load measuring device to be used. 11. A seat load measuring device for measuring a load applied to a seat, a load sensor for detecting a weight of the seat and a weight of an object on the seat, an amplifier for amplifying a signal from the load sensor, and a tare adjusting unit. A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a normal value is provided. It is stored as the initial adjustment amount, and thereafter, every time the tare adjustment is performed,
By comparing the adjustment amount at that time with the initial adjustment amount,
A method of diagnosing a seat load measuring device, comprising diagnosing whether the seat load measuring device is normal. 12. A seat load measuring device for measuring a load applied to a seat, a load sensor for detecting a weight of the seat and an object on the seat, an amplifier for amplifying a signal from the load sensor, and a tare adjusting unit. A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a normal value is provided, wherein a tare adjustment is performed with a seat placed on a load sensor, and a sheet load at that time The output of the measuring device is stored as an initial value, and thereafter, the output of the seat load measuring device is measured in a state where no object is mounted on the seat, and the measured value is compared with the stored initial value. A method for diagnosing a seat load measuring device, comprising diagnosing whether the load measuring device is normal. 13. A seat load measuring device for measuring a load applied to a seat, a load sensor for detecting the weight of the seat and the weight of an object on the seat, an amplifier for amplifying a signal from the load sensor, and a tare adjusting unit. A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a normal value is provided, wherein a tare adjustment is performed in a state where a sheet is not placed on a load sensor, and the adjustment amount is set to a first value. The adjustment amount A is stored as the first adjustment amount A, the tare adjustment is performed again with the sheet placed on the load sensor, and the adjustment amount is set as the second adjustment amount.
And thereafter, the load applied to the seat is measured using these two adjustment amounts, and the output of the load measuring device is the value obtained using the adjustment amount B. A method of diagnosing a seat load measuring device, characterized in that when a measurement value obtained by using the adjustment amount A exceeds a predetermined value, at least one of outputting a warning and performing a correction operation is performed. 14. A seat load measuring device for measuring a load applied to a sheet, a load sensor for detecting a weight of the sheet and a weight of an object on the sheet, an amplifier for amplifying a signal from the load sensor, and a tare adjusting unit. A method of diagnosing a seat load measuring device for diagnosing whether or not a measurement value of a device having a normal value is provided, wherein a predetermined load is applied to the load sensor in a state where the sheet is not mounted on the load sensor, and a tare adjustment is performed. And stores the adjustment amount as a first adjustment amount C,
Thereafter, the tare adjustment is performed with the sheet placed on the load sensor, and the adjustment amount is stored as a second adjustment amount D,
Thereafter, the measurement of the load applied to the seat is performed using these two adjustment amounts, and the output of the load measuring device is output using the adjustment amount D, and the adjustment is performed using the adjustment amount C. When the measured value exceeds a predetermined value, at least one of outputting an alarm and performing a correction operation is performed. 15. A seat load measuring device for measuring a load applied to a sheet, comprising: a load sensor for detecting a weight of the sheet and a weight of an object on the sheet; an amplifier for amplifying a signal from the load sensor; A diagnostic method of a seat load measuring device for diagnosing whether a measured value of a device having a sensitivity adjusting unit is normal or not, in which a sensitivity adjustment value performed at an initial stage is stored, and thereafter, when a sensitivity adjustment is performed. A diagnostic method for diagnosing whether the seat load measuring device is normal or not by comparing with a sensitivity adjustment value of (1).