JP2003135643A - Sensor board for detecting start operation, and start operation-judging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make further accurate a start operation-judging apparatus, to provide the start operation-judging apparatus that can be also applied to the race of a car such as a wheelchair, and to provide a sensor board for detecting start operation. SOLUTION: A sensor 1 such as a strain gauge that is provided near a position where the deflection of a board on the surface of a sensor board 2 for detecting start operation is maximized is provided. An input signal obtained by A/D-converting the output signal of the sensor 1 is compared with two comparison signals obtained by smoothing and delaying the input signal and giving a threshold up and down to generate a detection signal. Time at the point of inflection of a comparison signal immediately nearby by going back from the second time that is delayed by specific time from the first time where a signal in detection is generated is specified. Based on it, a player obtains the starting point of the start operation, thus accurately obtaining the operation start point without any errors due to the threshold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start action detecting sensor board for determining a start action of a competitor and a start action determining device.

[0002]

2. Description of the Related Art At present, there is a start motion judging device used for judging the flying condition of athletics, especially at the start of a short distance event. Flying starts with a start sound (start signal) when the competitor does not stand still within an appropriate time (approximately 2 seconds) from the starter's "Good" signal.
It is said that the start operation is started in less than 0.100 seconds. The start motion determination device is for detecting a competitor's start motion and making a determination of flying by comparing the detection timing with the generation timing of the start signal. For example, JP-A-8-22
There is one disclosed in Japanese Patent No. 9179. This is shown in FIG.
As shown in FIG. 6, a sensor 62 is provided on the starting block 61 so as to receive a rearward load applied to the foot plate of the starting block 61 by the start motion of the athlete, and the output of the sensor 62 is used as the start determination device 6
3, the start operation is determined. As shown in FIG. 7, the start determination device 63 includes a low pass filter 71, an A / D conversion circuit 72, a smoothing circuit 73,
The delay circuit 74, the addition circuit 75, and the comparison circuit 76 are included. The low-pass filter 71 removes the noise component of the sensor 62 and supplies it to the A / D conversion circuit 72. A
The / D conversion circuit 72 A / D converts this output to generate a first digital signal. The smoothing circuit 73 takes a moving average of the first digital signal of a predetermined number of samples, smoothes it, and outputs it as a second digital signal. The adder circuit 75 adds a reference value as a threshold value for separating noise due to slight body shake other than the start motion of the athlete to the second digital signal that has passed through the delay circuit 74, and the second digital signal is added. Apply offset to digital signals. The comparator circuit 76 compares the first digital signal with the second digital signal offset by the adder circuit 75, detects a match between these digital signals, and determines this as a start operation. Since the start determination device 63 detects an increase in the specific frequency component of the output voltage of the sensor 62 caused by the start operation, it is possible to determine the start operation with high accuracy.

Some athletes put their toes on the upper end side of the foot plate 64 of the starting block 61 when they reach the starting position. In this case, the heel located behind the upper end of the foot plate 64 during the stepping motion. Is applied to the foot plate 64, and the foot plate 64 is strongly applied downward rather than backward, and the force applied to the sensor 62 is rapidly reduced. Although not described in detail, as an attempt to cope with the start operation in which the force is reduced, two upper and lower reference values are added to the second digital signal and the upper and lower limits of the window comparator are compared with the first digital signal. It may take a configuration.

[0004]

Although the start determination device 63 of FIG. 7 enables highly accurate start operation determination,
There is a problem that an error occurs due to the size of the reference value. For example, FIG. 8 shows an input signal from the sensor 62 via the low-pass filter 71 and the A / D conversion circuit 72, and a comparison signal based on three reference values from the addition circuit 75 to be compared with the input signal. As shown in the same figure, the operation detection point, which is the determination timing, is different due to the difference in the reference value.

At present, wheelchair races are being conducted in the Paralympics and the like, but the above-mentioned start determination device is specialized in the use of starting blocks and cannot be applied to wheelchair races as it is. The reason is as follows. In the wheelchair for racing, the front wheels extend forward, and when performing the start motion, the starter (referee) gives a "position" signal and the front wheel is aligned with the start line, and the start signal (gun) is used. To start. Even if a sensor is placed under the front wheel and movement judgment is performed based on the change in the load applied to the sensor, the load change during the start operation is small compared to when a starting block is used, and a more strict reference value Although the setting is necessary, the error due to the setting of the reference value cannot be denied as described above, and it cannot be a realistic method. For this reason, there has been no attempt to use a start determination device.

It is an object of the present invention to provide a start motion determining device and a start motion detecting sensor board which can be applied to a race of a car such as a wheelchair while improving the accuracy of the start motion determining device.

[0007]

SUMMARY OF THE INVENTION A motion detection sensor board of the present invention is a board which is flexibly supported by a competitor through a support member and is installed at a competition start position in response to a competitor's start motion. And a sensor such as a strain gauge provided in the.

This sensor board is used for detecting a start motion by placing a wheel of a wheelchair, a bicycle or a car on which the athlete rides on the board before starting.

Further, it is preferable that the board is installed corresponding to the start line, and the start line is displayed on the surface of the board.

It is also preferable that the sensor is provided near the support member.

The start motion judging device of the present invention receives the start motion of the athlete, converts the output signal of the sensor to a first digital signal, and the first digital signal. The first digital signal is smoothed by a desired number of samplings to obtain a second digital signal, and the second digital signal and the first digital signal are compared, and a difference of a predetermined value or more is obtained. A detection means for generating a detection signal when it occurs and the second digital signal are stored in association with time, and the first detection signal is generated.
Start by determining the time of the most recent inflection point of the second digital signal, traced back from the second time delayed by a predetermined time from the time of, and judging that the athlete has performed the start action based on the specified time And a motion determining means.

Here, the sensor may be a sensor such as a strain gauge provided on a board installed at a competition start position, which is flexibly supported by a support member via a support member in response to the start operation of the competitor. preferable.

The starting point of the start operation is the second point for the first digital signal from the specific time.
It is preferable that the time is traced back by the delay time of the digital signal.

It is also preferable that the predetermined time is a delay time of the second digital signal with respect to the first digital signal.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail based on examples with reference to the accompanying drawings.

A start operation detection sensor board and a start operation determination device according to a practical example of the present invention will be described. This example describes a motion detection sensor board for detecting a start motion for a wheelchair race and a start motion determination device applicable to the motion detection sensor board. FIG. 1 is a block diagram showing the configuration of the start operation determination device of this example. The sensor 1 is composed of a sensor such as a strain gauge provided on a start motion detection sensor board 2 on which the front wheel FW of the wheelchair is placed at the time of starting, and generates a voltage output signal according to the motion of the athlete on the wheelchair. Details of the sensor 1 and the start operation detection sensor board 2 as the operation detection sensor board will be described later.

The A / D converter 3 receives the output signal from the sensor 1 as an input signal, and A / D-converts and quantizes the output signal at a predetermined sampling period, for example, 1 ms.

The moving average circuit 4 receives the digital signal from the A / D converter 3, performs a moving average calculation of m pieces of data having a predetermined sampling time, and smoothes the input signal.
Here, m is a predetermined integer that is appropriately determined. For example, if the sampling period is 1 ms and a moving average of 25 ms before and after a specific timing is taken, m is 5
It becomes 1. In the moving average calculation, for example, the delay circuit 42, which delays the data by m, supplies the data, and the adder 41 cumulatively adds the data sequentially input from the A / D converter 3 while delaying the delay circuit 42. Can be realized by subtracting the data delayed by m and dividing by a predetermined number m in the divider 43.

The delay circuit 5 delays the average value signal, which is a digital signal from the moving average circuit 4, and delays each data of the average value signal, that is, the average value data by k. Here, k is a predetermined integer that is appropriately determined. For example, when k is 25, the data output from the delay circuit 5 is 50 together with the delay due to the smoothing described above.
Get ms delay.

The window comparator 6 vertically offsets the average value signal passed through the delay circuit 5 and uses two comparison signals as a window between them, and the data from the A / D converter 3 deviates from the window. This is detected and a detection signal is generated. For example, the window comparator 6 includes an adder 61, a subtractor 62, a comparison circuit 6
It consists of 3, 64. Each data of the average value signal delayed by the delay circuit 5, i.e., the predetermined threshold value P _S1 by the adder 61 while the average value data is added, the predetermined threshold P _S2 by the subtractor 62 on the other hand Subtraction is performed to obtain two comparison data S1 and S2. That is, two comparison signals are obtained. The comparison circuit 63 compares the comparison data S1 obtained based on the threshold P _S1 with the data from the A / D converter 3, and the data from the A / D converter 3 is compared with the comparison data S1.
When it exceeds, a detection signal is generated. The comparison circuit 64 compares the comparison data S2 obtained based on the threshold value P _S2 with the data from the A / D converter 3, and when the data from the A / D converter 3 falls below the comparison data S2. Generate a detection signal.

The operation start point detection circuit 7 as the start operation determination means receives the comparison signal and the detection signal from the window comparator 6, and executes the operation start point detection process described later based on these signals, and Detects the timing when the start operation is started, that is, the operation start point.

Next, with reference to FIG. 2, the structure of the start operation detecting sensor board 2 will be described. 2A shows a schematic diagram of the start operation detecting sensor board 2, and FIG. 2B shows a schematic cross-sectional view taken along the line AA of FIG. 2A. Sensor board for start operation detection 2
Is equipped with biaxial strain gauges 21 and 22, and the biaxial strain gauges 21 and 22 constitute the sensor 1. The sensor board 2 for detecting the start operation is shown in FIG.
As shown in FIG. 2, the support members 25 and 26 located at both ends of the two boards 23 and 24 are sandwiched between the boards 23 and 24, and one of the board 23 which is the surface when used is supported on the board 24 which is the installation surface. 2 along the support member 25
Axial strain gauges 21 and 22 are provided. Board 23
A start line 27 is provided on the other support member 26 side. The competitor will put the front wheel of the racing wheelchair on the start motion detection sensor board 2 in line with the start line 27. At this time, the portion between the support members 25 and 26 of the board 23 bends, and the distortion of the board 23 becomes maximum in the vicinity of the support members 25 and 26. Therefore, the biaxial strain gauges 21 and 22 provided here can effectively receive strain.

Connection relationship between the two-axis strain gauges 21 and 22
Is, for example, the direction of line AA is the X-axis direction and
Align the direction of the 2-axis strain gauges 21 and 22 in the Y-axis direction.
If it faces, it becomes like FIG. 2-axis strain gauge 2
1 X-axis resistance component R_X21And 2 axis strain gauge 22
X axis resistance component R_X222 axis strain gauge
21 Y-axis resistance component R_Y21And 2 axis strain gauge 2
2 Y-axis resistance component R_{Y twenty two}Bridge to play with
The circuit is configured. Resistance component R_X21And resistance component R_Y22When
The connection point of is connected to the power supply terminal VDD, and the resistance component R_X22When
Resistance component R_Y21Connect the connection point with and to the power supply terminal VSS
A power supply voltage is applied between these connection points, and the resistance component R_X21And
Anti-component R_Y21Output terminal Out1 connected to the connection point with
And the resistance component R _X22And resistance component R_Y22Connect to the connection point with
An output voltage is generated between the output terminal Out2 and the output terminal Out2. this
Generates output voltage against distortion in both X-axis and Y-axis.
To live. The output signal of the sensor 1 obtained as this output voltage
No. changes in the vertical load on the board 23 and wheelchairs.
By moving the pressure position by the front wheel of the child back and forth,
Change.

Next, the operation of this example will be described. The output signal from the sensor 1 is supplied as an input signal to the A / D converter 3, and is A / D converted and quantized by the A / D converter 3 at a predetermined sampling period. The quantized digital signal (hereinafter, referred to as an input signal for convenience of description) is smoothed by a moving average calculation of m pieces of data by the moving average circuit 4 to obtain an average value signal from which noise is removed. Become. This digital signal is converted into k by the delay circuit 5.
It is delayed by the sampling time of each piece of data. The delay time Δt of the average value signal through the delay circuit 5 is represented by the number m of moving averages in the moving average circuit 4 and the number k of delays in the delay circuit 5, and is (m−1) / 2 and k. It is a value obtained by multiplying the sum of by the sampling period.

The average value signal from the delay circuit 5 is given two upper and lower offsets by the thresholds P _S1 and P _S2 by the window comparator 6, and two comparison signals are compared with the input signal through the A / D converter 3. It is said that The window comparator 6 detects that the input signal via the A / D converter 3 deviates from the window between the two comparison signals and generates a detection signal.

As a result, the amount of change in the input signal when the athlete starts the start operation is calculated by the input signal from the A / D converter 3 and the delay signal from the delay circuit 5 (that is, through the delay circuit 5). The average value signal.) Is subtracted from the average value signal. The extracted change amount signal Δy (t) can be regarded as a change amount of the input signal per delay time Δt at the rising portion of the input signal. The detection signal of the start motion of the athlete is generated when the variation signal Δy (t) exceeds the threshold P _S1 or falls below the threshold P _S2 . Here, the thresholds P _S1 and P _S2 are set to values corresponding to changes in the input signal due to fluctuations of the body of the athlete in a stationary state.

Now, the characteristics of the operation determination system will be described with the A / D converter 3, the moving average circuit 4, the delay circuit 5 and the window comparator 6 as the operation determination system.

The transfer function of m moving averages is expressed by the following equation (1).
Indicated by.

[Equation 1]

From this equation (1), the sampling period is T
Then, the frequency response is calculated as shown in the following equation (2).

[Equation 2]

When the amplitude characteristic G (ω) and the phase characteristic φ (ω) to which the number of delays k is added are obtained from the equation (2), the following equations (3) and (4) are respectively obtained.

[Equation 3]

[Equation 4]

The input signal x (t) of the motion judging system is
DC component V _DC and AC component V _AC s appearing from fluctuation of force
in (ωt), and becomes as in the following Expression (5).

[Equation 5]

The delay signal y (t) of the operating system is obtained by calculating the moving average of the input signal x (t) and delaying it, so that the following equation (6) is obtained.

[Equation 6]

Delay signal y as shown in equation (6)
(T) is the amplitude characteristic G of the moving signal in the input signal x (t).
(Ω) and the phase characteristic φ (ω) due to the moving average and the delay.

The change amount signal Δy (t) is the input signal x
It is obtained by subtracting the delay signal y (t) from (t), and is given by the following expression (7).

[Equation 7]

As shown in equation (7), the change amount signal Δy
The frequency characteristic of (t) becomes small at low frequencies and becomes large at high frequencies. The detection signal is the change amount signal Δy
This occurs when (t) exceeds the threshold value P _S1, and therefore occurs when the following relational expression (8) is satisfied.

[Equation 8]

The detection signal is the change amount signal Δy (t).
Occurs even when is below the threshold value P _S2 , so it also occurs when the following relational expression (9) is satisfied.

[Equation 9]

As shown in the relational expressions (8) and (9),
The characteristics of the motion determination system are characteristics that are well suited for motion detection, such that the detection sensitivity is low at low frequencies and the detection sensitivity decreases at higher frequencies.

However, as described as a conventional problem, the generation timing of the detection signal from the window comparator differs depending on the threshold value, and is as follows, for example. FIG. 4 shows the input signal and three different thresholds P
_The comparison signal with respect to _S1 and the amount of change between the data of the comparison signal multiplied by 20 are shown as the relationship between the input (kgf) and time (ms) applied to the corresponding sensor 1, In the figure, the threshold P _S1 is
It corresponds to three reference values of 3 kgf, 5 kgf, and 7 kgf. The generation timing of the detection signal from the window comparator is the intersection of the input signal and the comparison signal, and differs depending on the reference value, that is, the threshold value P _S1 . Further, FIG. 4 shows a case where the input signal rises for convenience of explanation.

Therefore, in this example, the generation timing of the detection signal is not the timing at which the athlete starts the start motion as it is, but the motion detection point which is the generation timing of the detection signal is processed by the process described below by the motion start point detection circuit 7. The start point of the action, which is the timing when the competitor starts the start action, is detected. This will be described with reference to the flowchart of FIG.

The operation start point detection circuit 7 receives the data of the comparison signals sequentially output from the window comparator 6,
Each data is stored in a storage unit (not shown) in association with a time received from a time counting unit (not shown) (step A). Although this comparison signal corresponds to the threshold value P _S1 , it may correspond to the threshold value P _S2 . During this time, it is determined whether or not a detection signal is generated from the window comparator 6 (step B). If the detection signal is generated here, the time t1 at which the detection signal is generated is specified (step C). This time t1 is set as the motion detection point t1. Next, from time t1 to time t2 after delay time Δt1 by the delay processing of the delay circuit 5.
Is specified (step D). That is, since the comparison signal has the delay time Δt1 due to the delay processing with respect to the input signal, the time t when the delay time Δt1 has elapsed from the operation detection point t1.
2 is the operation detection point t2 in the comparison signal. With this as the starting point, the time of the inflection point of the comparison signal is specified by tracing back the time by the following processing.

Next, the data at time t2 is compared with the immediately preceding data (step E). Here, it is determined whether the amount of change between the data has become 0, or whether the positive / negative has been inverted (step F). That is, the inflection point of the comparison signal is determined depending on whether the slope of the comparison signal becomes 0 or whether the positive / negative of the comparison signal is inverted. For example, the window comparator 6
When the detection signal is generated from the comparison circuit 63, that is, when the input signal rises, it is determined whether or not the data of the comparison signal is larger than the previous data, and if not larger, the change amount is a positive value. From 0 to a negative value. Further, when the detection signal is generated from the comparison circuit 64 of the window comparator 6, that is, when the input signal falls, it is determined whether or not the data of the comparison signal is smaller than the data immediately before it, and if it is not small, it changes. It is determined that the amount has changed from a negative value to 0 or a positive value.

In step F, if the amount of change has become 0 or its sign has not been reversed, the data is traced back by one and the traced data is compared with the preceding data (step G). Here, it is determined whether the amount of change between data has become 0 or whether its positive / negative has been inverted (step H). If the amount of change has become 0 or its positive / negative has not been inverted, the process of step G is performed. Return to. Step G,
The time t at which the amount of change in the comparison signal becomes 0 or its sign is reversed by repeating the processing of H and tracing back the data
3 is specified, and this is set as the operation start point t3 in the comparison signal (step I).

Next, the time t4, which is the delay time Δt1 due to the delay processing from the time t3, is set as the operation start point t4 of the input signal (step J). That is, the comparison signal includes the delay time Δt1 due to the delay process and is delayed by that amount with respect to the input signal.
The time t4 traced back by t1 is obtained as the operation start point t4 of the input signal. In this example, the time t4 is set as the operation start point of the competitor's start operation.

In this example, as shown in FIG.
If the intersection of the comparison signal with Kg as the reference value and the input signal is time t1 at which the detection signal occurs, the amount of change between data is 0 while tracing back the data from the data of the comparison signal from time t2 delayed by Δt1. Alternatively, the time t3 of the data whose sign is inverted is specified, and the time t4, which is further back by Δt1, is set as the operation start point. As shown in FIG. 4, if the intersection of the input signal and the comparison signal is used as it is as the operation detection point as in the prior art, the operation detection point differs depending on the reference value, that is, the threshold value. On the other hand, the amount of change obtained from the comparison signal does not depend on the reference value. Therefore, the motion detection point is specified from the change amount, and this is set as the delay time Δ
By correcting at t1, the input signal motion detection point t4
By doing so, it becomes possible to obtain a highly accurate motion detection point in which an error due to the reference value is suppressed. Moreover, since the motion detection point is obtained based on the comparison signal, that is, basically the average value signal, it is possible to further suppress the influence of noise caused by a slight body movement of the athlete that cannot be regarded as the start motion. Also, the motion detection point t in the comparison signal
Since the process of identifying the inflection point is started from 2 as the starting point, the amount of change in the comparison signal is sufficiently large, and the same inflection point can be identified with different threshold values, that is, the same operation start point can be identified. Moreover, since the inflection point identification process is performed starting from a time that is as close to the operation start point as possible, the amount of data for the process can be suppressed and the processing time can be suppressed.

If the time of the operation start point t4 is given to the unauthorized start determination device 8 as described in the above-mentioned Japanese Patent Laid-Open No. 8-229179, the unauthorized start determination device 8 will obtain the obtained operation start point. If the time t4 is compared with the time of generation of the start signal from the start signal generator 9 to make an illegal start, that is, a determination of flying is made, a more accurate flying determination can be made than the conventional one. .

As described above, in the wheelchair race, the athlete waits so that the front wheels of the racing wheelchair fit the start line. In this example, the start motion detection sensor board 2 is installed corresponding to the start line, and the front wheels are placed on the board 23 so as to match the start line 27 displayed on the board 23 on the surface of the start motion detection sensor board 2. Can be posted. When a competitor performs a start motion, the center of gravity moves to the rear wheels and the load on the front wheels decreases, which reduces the load on the board 23, and the load on the board 23 increases due to body shaking during the start motion. To do. Such a change in load is smaller than the load applied to a conventional starting block, and the start operation is detected by simply comparing the load with a predetermined reference value or from the intersection of the input signal and the comparison signal. Therefore, more strictness is required for setting the reference value, that is, the threshold value, and an error occurs for each threshold value. In this example, the operation start point of the comparison signal is obtained from the amount of change between the data of the comparison signal, and the operation start point of the input signal is obtained by correcting the operation start point of the comparison signal. Since it is possible to accurately determine the start motion, it is possible to determine the start motion of a wheelchair race.

Sensor board 2 for detecting the start operation of this example
Are support members 25 located at both ends of the boards 23, 24,
26 is sandwiched between boards 23 and 24, and biaxial strain gauges 21 and 22 are provided in the vicinity of one support member 25 of the board 23, which is the surface when used. As a result, the load change on the start operation detecting sensor board 2 is converted into the bending of the board 23, and this is detected by the biaxial strain gauges 21 and 22 provided at the position where the distortion due to the bending is maximized. It is possible to effectively convert the load change in the vertical direction with respect to, and the change in the plane direction of the pressurization position by the front wheel of the wheelchair or the like into an electric signal. In this example, two two-axis strain gauges are used, but not limited to this, four one-axis strain gauges are used and two one-axis strain gauges are used for X-axis strain gauge.
Two axes, an axis and a Y axis, may be configured and connected as a two-axis strain gauge in the same manner as this example. Further, the sensor is not limited to a strain gauge, but may be any sensor as long as it receives a distortion due to the bending of the board 23 and converts it into an electric signal, such as a piezoelectric element.

Further, the support member 25 is made thinner than the thickness of the support member 26, or the end portion of the board 24 is used as a substitute so that the start motion detecting sensor board 2 is inclined so as to become higher toward the start line. In addition, the wheelchair may be easily mounted on the start motion detection sensor board 2.

In the above embodiment, the sensor board for detecting the start motion of the present invention has been described by taking the wheelchair race as an example, but the sensor board for detecting the start motion of the present invention is not limited to the wheelchair race. For example, in a competition using a car such as a bicycle or an automobile, if a start motion detection sensor board is installed so that the wheels of the car are mounted immediately before the start and used for the start motion determination, the same action as that of the above-described embodiment is obtained. , Effective. Further, if the start motion detection sensor board of the present invention is installed on the start table of a swimming race, highly accurate start motion determination is possible even in a swimming race.

In the above embodiment, the start motion determining device of the present invention is applied to a wheelchair race, but the start motion determining device of the present invention is not limited to this. For example, the start motion determining device of the present invention can be used as a start motion determining device for athletics using a starting block as described in Japanese Patent Laid-Open No. 8-229179. For example, instead of the sensor board 2 for detecting the start operation, the output signal of the sensor provided in the starting block may be input to the operation determination system of the above embodiment.

Further, in the above-mentioned embodiment, the time of the inflection point of the comparison signal is obtained as the specific time, and the time which is traced back by the delay time Δt1 in the delay circuit 5 is set as the operation starting point, but the present invention is not limited to this. Not a thing. For example, the comparison signal is obtained by delaying and further offsetting the average value signal from the moving average circuit 4, but instead of such a comparison signal, an average without delay by the delay circuit 5 with respect to the input signal. It is also possible to use the value signal to obtain the time of the inflection point of the average value signal as the specific time, and use the obtained specific time as it is as the operation start point.

[0052]

EFFECT OF THE INVENTION The sensor board for detecting the start motion of the present invention is provided on the board and a board which is supported by a support member so as to be flexible in response to the start motion of a competitor and is installed at the competition start position. Since it is composed of a sensor such as a strain gauge, it is effective to use a sensor that detects the strain due to the bending of the board for the load change in the vertical direction to the board due to the start action of the athlete and the change in the plane direction of the pressing position. It becomes possible to make an electric signal, and it becomes possible to detect the start operation with high sensitivity. In particular, if the sensor is provided in the vicinity of the support member where the distortion of the board is maximum, it is possible to detect the start operation with higher sensitivity.

Further, the start operation judging device of the present invention is
The first digital signal obtained from the output signal of the sensor is compared with the second digital signal obtained by smoothing the first digital signal, and a detection signal is generated when a difference of a predetermined value or more occurs, and the detection signal is generated. The latest time point of the inflection point of the second digital signal is specified retroactively from the second time delayed by a predetermined time from the first time, and the start motion of the athlete is determined based on the specified time. As a result, it is possible to suppress an error in the starting point of the start operation due to the difference in the operation determination threshold value given as the predetermined value, and it is possible to provide a highly accurate start operation determination device.

Further, since the starting point of the starting operation is obtained based on the inflection point of the second digital signal obtained by smoothing the first digital signal, noise caused by slight fluctuations of the body of the competitor who cannot be regarded as the starting operation. The influence is suppressed as much as possible, and from this point also, the accuracy of the start motion determination device is being improved.

By setting the above-mentioned predetermined time as the delay time of the second digital signal with respect to the first digital signal, the second digital signal has a sufficiently large inclination.
By specifying the inflection point retroactively from the time of, it is possible to specify the starting point of the same start operation for different thresholds, and to perform the inflection point specifying process starting from the time as close as possible to the starting point. The amount of data for processing can be suppressed, and the processing time can be suppressed.

By combining the start motion detecting sensor board and the start motion determining device of the present invention, it is possible to construct a start motion determining device for a race using a vehicle such as a wheelchair that can withstand practical use. For example, if the front wheel is placed on the motion detection sensor board at the start of a wheelchair race, it is effective when the load of the front wheel is released by the start operation or when the pressure position of the front wheel changes in the plane direction. It can be converted into an electrical signal. Compared to the case of using a starting block in a wheelchair, the change in the load on the sensor during start operation is small, and
The load is often reduced by the start operation, and it is desirable to set a stricter reference value, but the start operation determination device of the present invention suppresses the error due to the threshold value and enables highly accurate operation determination. It can sufficiently meet such demands.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a start operation determination device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the configuration of a start operation detection sensor board according to the embodiment of the present invention.

FIG. 3 is an electric circuit diagram showing the connection relationship of the strain gauges of the start operation detection sensor board.

FIG. 4 is a waveform diagram for explaining the operation of the start operation determination device in FIG.

5 is a flowchart for explaining the operation of the start operation determination device in FIG.

FIG. 6 is an explanatory diagram for explaining an outline of a conventional start operation determination device.

FIG. 7 is a block diagram showing a configuration of a conventional start operation determination device.

FIG. 8 is a waveform diagram for explaining the operation of the conventional start operation determination device.

[Explanation of symbols]

1 sensor 2 Start operation detection sensor board 21, 22 Strain gauge 23 boards 3 Conversion means (A / D converter) 4 Detection means (moving average circuit) 5 Detection means (delay circuit) 6 Detection means (window comparator) 7 Start operation determination means (operation start point detection circuit)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F085 AA05 CC04 EE01 FF04 FF15                       FF20                 3E038 AA07 BA01 BA07 CA03 CA07                       CC01 EA02 EA05 GA01 HA03                       HA05

Claims (8)

[Claims] 1. A board, which is flexibly supported by a support member via a support member in response to a start operation of a competitor and is installed at a competition start position, and a sensor such as a strain gauge provided on the board. Sensor board for detecting start motion. 2. The wheel according to claim 1, wherein a wheel of a wheelchair, a bicycle, an automobile, or the like on which the athlete rides is placed on the board before the start and used for detecting a start motion. Sensor board for start motion detection. 3. The start motion detecting sensor according to claim 1, wherein the board is installed corresponding to a start line, and the start line is displayed on the surface of the board. board. 4. The sensor board for detecting a start motion according to claim 1, wherein the sensor is provided in the vicinity of the support member. 5. A conversion means for converting an output signal of a sensor generated in response to a player's start operation into a first digital signal, and receiving the first digital signal, with respect to the first digital signal. A second digital signal is obtained by performing smoothing for a desired sampling number, the second digital signal is compared with the first digital signal, and when a difference of a predetermined value or more occurs, the detection signal is detected. The detecting means for generating and the second digital signal are stored in correspondence with the time, and the second digital signal immediately after the second time delayed by a predetermined time from the first time when the detection signal is generated is stored. A start motion determination device comprising: a start motion determination means for determining a time of an inflection point of a digital signal and determining that the athlete has performed a start motion based on the specific time. 6. The board according to claim 5, wherein the sensor is supported by a support member so as to be flexible in response to a start operation of the athlete, and is provided on a board installed at a competition start position. The described start motion determination device. 7. The start point of the start operation is obtained as a time point that is traced back from the specific time point by a delay time of the second digital signal with respect to the first digital signal. The described start motion determination device. 8. The start operation determination device according to claim 5, wherein the predetermined time is a delay time of the second digital signal with respect to the first digital signal.