JPH03244438A - Gravity center swing device - Google Patents

Abstract

PURPOSE:To provide possibility of calculating the position of center of gravity having got rid of influence of the drift value by sensing drift value of a plurality of load sensors mounted on a stamping platform, and calculating the position of the center of gravity from the sensing signals given by load sensors which have been corrected on the basis of the sensing values. CONSTITUTION:Outputs from load sensors 2, 3, 4 mounted on a stamping platform 1 are fed to a calculator circuit 12 and also to a drift sensor 10, and the output therefrom is fed to a drift correct value calculating circuit 11, which is connected with the calculator circuit 12 in connection with a display 6. First, the power supply of the device is put on, and drift values of the load sensors 2, 3, 4 are sensed by the drift sensor 10 and fed to the drift correct value calculating circuit 11, where computation of the correction value is performed. Then the person to be inspected gets on the platform 1, and the sensing values of the load sensors 2, 3, 4 are taken into the calculator circuit 12, where drift correction of each sensing value is performed. Then the computation of the central position of gravity is executed on the basis of the sensing signals of the load sensors 2, 3, 4 having undergone corrections, and signal about the central position of gravity (x), (y) is fed to the display 6, where the locus of the center of gravity is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a center of gravity sway meter that calculates the position of the center of gravity of a subject.

<Conventional technology> The upright standing posture is the basic posture of humans, and by understanding the position of the center of gravity and the state of sway of the center of gravity when this posture is taken, it is possible to improve the physical function of the subject through clinical examinations, diagnosis, and rehabilitation. It is possible to check the degree of recovery of patients and to understand the state of drug addiction.

Figure 3 is a block diagram showing the configuration of a conventional center of gravity sway meter.
A load sensor 2 is installed at each vertex position of the isosceles triangular step stool 1 on which the subject stands. 3. 4 are attached to each load sensor 2. 3. 4 are signal lines respectively, and the center of gravity calculation circuit 50
The output terminal of the center of gravity calculation circuit 5 is connected to the display 6.

Set the X-y coordinates with the load sensor 2 position as the origin,
The coordinates of the load sensor 3 are (9, m), the coordinates of the load sensor 4 are (-Q, m), and the center of gravity of the subject is (+r, y),
The weight of the subject is measured by the load sensor 4. 3. 2 detection load as PI, P2. If P3, W = P 1+ P
2 + P 3, and the following equation is obtained from the moment equilibrium condition.

P2S5-W-X = P +9--=' (1) (
Equation (2) is obtained from Equation 1).

(P2-PI) Q ・・・・・・・・・(2)X
= Equations (3) and (4) are obtained in the same way.

W-y==mP++mP2-...-(3) In FIG. 3, load sensor 2. 3. The detected load signals from 4 are input to the center of gravity calculation circuit 5, and the center of gravity calculation circuit 5 performs the calculations shown in equations (1) to (4) based on these detection signals, with the position of the load sensor 2 as the origin. will be held.

The center of gravity calculation circuit 5 outputs the center of gravity position signal X+'/ obtained by calculating equations (2) and (4), and inputs it to the display 6. The display 6 displays a locus 7 based on the center of gravity position signals X and V, so the total length of this locus 7, the so-called locus length, the area included in the locus 7, etc. are calculated and used for clinical examination of the subject. It is possible to perform drug diagnosis, check the degree of recovery of physical functions through rehabilitation, and understand the state of drug addiction.

<Problems to be Solved by the Invention> A load sensor used in a center of gravity meter has a reference potential (zero potential) that fluctuates from OV due to the atmosphere in which it is used or over time.

For this reason, in the conventional center of gravity oscillation meter described above, the detected loads P + , P 2 + P 3 due to the operating atmosphere or over time
This means that the detected values are fluctuating, and using these detected values as they are, the center of gravity position (x, y) calculated using equations (2) and (4) is calculated by calculating the drift error of the load sensor. It is included.

For each measurement, load sensor 2. 3. It is conceivable to measure the drift values of 4 and perform calibration by providing a calibration circuit so that the drift values of each load sensor become 0, but this would make the calibration work complicated.

The present invention was made in view of the current state of the conventional center of gravity oscillation meter described above, and its purpose is to correct the drift value of the load sensor in conjunction with the calculation of the center of gravity position, thereby significantly reducing the influence of the drift value. It is an object of the present invention to provide a center of gravity meter that calculates the position of the center of gravity with a reduced value.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a step stool on which a subject stands, a plurality of load sensors attached to the step stool, and a drift device for detecting drift values of these load sensors. a detector; a correction value calculation means for calculating a correction value based on the detection value of the drift detector; and a correction value calculation means for calculating a correction value based on the detection value of the drift detector; The center of gravity calculation means is configured to calculate the following.

Effect> In the present invention, the drift value of the load sensor is detected by the drift detector, and the correction value is calculated by the correction value calculation means.

Then, based on the detection signal of the load sensor corrected by this correction value, the center of gravity calculation means calculates the center of gravity position of the subject.

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is a flowchart showing the operation of the embodiment of the present invention.

As shown in FIG. 1, in the embodiment, a load sensor 2. 3. 4 is connected to the input terminal of the arithmetic circuit 12, and the output terminal of the drift detector 1
It is also connected to the 0 input terminal.

The output terminal of this drift detector 10 is connected to the input terminal of the drift correction value calculation circuit 11, the output terminal of the drift correction value calculation circuit 11 is connected to the calculation circuit 12, and the output terminal of the calculation circuit 12 is connected to the input terminal of the drift correction value calculation circuit 11. 6.

Next, the operation of the embodiment will be explained.

In step Sl of the flowchart shown in FIG.
The power of the device is turned on, and in step S2 it is determined whether the power is turned on. If this determination is YES, step S3
Then, the drift values of the load sensors 2, 3.4 are measured by the drift detector IO.

In step S4, load sensor 2. 3. 4 is detected by the drift detector lO, this drift value is manually inputted to the drift correction value calculation circuit 11, and when it is confirmed that the drift value capture is completed, step S5
Then, the calculation of the drift correction value is performed.

In the example, the drift value of the load sensor 2.3.4 detected by the drift detector IO is V d 21 V d 3
1V d a , and the average drift value is calculated as the drift correction value d using the following equation.

When it is confirmed in step S6 that the calculation of the drift correction value has been completed, the process proceeds to step S7 and the subject is placed on the step stool.
, and in step S8, the load sensor 2. 3.
A determination is made as to whether or not the detected value of No. 4 is equal to or greater than a preset threshold value, for example, 3 kg.

If the determination in step S8 is YES, the process advances to step S9, and the load sensor 2. 3. The detected value of load sensor 2.4 is taken into the arithmetic circuit 12, and the detected value of load sensor 2. 3. It is determined whether or not the detection value of No. 4 has been taken into the arithmetic circuit 12.

If the determination in step SIO is YES, step Sl
Proceed to l and load sensor 2. 3. Drift correction of the detected value of No. 4 is performed.

In the embodiment, the load sensor 2. 3. The detected value of V2. V3. As V4, the detection after correction [V
2C,V 3CIV ac is corrected by the following equation.

V2c:=V2-d V3c::V3-d・・・・・・・・・・・・(6)V
4c: V4-d It is determined whether the drift correction is completed in step S12, and if the determination in step 512 is YES,
Proceeding to step S13, the load sensor 2 corrected using equation (6). 3. Based on the detection signal No. 4, the center of gravity position is calculated using equations (2) and (4) described above.

The thus calculated signals of the center of gravity positions x and y free of drift errors are input to the display 6, and, for example, the locus of the center of gravity position is displayed.

In the embodiment, as described above, in the calculation by the calculation circuit 12, the load sensor 2 corrected by the drift correction value d is
．． 3. Since the calculation of the center of gravity position is performed using the detected value of No. 4, the calculation of the center of gravity position is performed with high accuracy with a significantly reduced drift error. Load sensor 2. 3. The detection of the drift value in step 4 and the calculation of the drift correction value based on this drift value are performed automatically, so there is no need to worry about the complicated load sensor 2.
．． 3. The drift calibration work in step 4 is no longer necessary.

In addition, although the example explained the case where the average value of the drift value of each load sensor was used as the drift correction value, the present invention is not limited to the example, and for example, the drift value measured for each load sensor It is also possible to use each as a drift correction value.

<Effects of the Invention> As described above in detail, according to the present invention, it is possible to calculate the center of gravity position while removing the influence of the drift value of the load sensor.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of a conventional center of gravity oscillation meter. 1... stepping stone, 2. 3. 4...Load sensor, 6
...Display device, 10...Drift detector, 11.
... Drift correction value calculation circuit, 12... calculation circuit. Figure 1 Figure

Claims (1)

[Claims] A step stool on which the subject stands, a plurality of load sensors attached to the step stool, a drift detector that detects the drift values of these load sensors, and a correction value calculated based on the detected values of the drift detector. A center of gravity sway meter comprising: a correction value calculation means; and a center of gravity calculation means for calculating the position of the center of gravity of the subject based on a detection signal of the load sensor corrected by the correction value.