JPH0581954B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a step counter equipped with a sensor that outputs a signal corresponding to walking, and particularly to a step counter equipped with a circuit that removes noise from the output signal of the sensor. be.

[Background technology]

Conventionally, a sensor consisting of a pair of contact electrodes, a strain gauge, a piezoelectric element, etc. is installed in the footrest of footwear.
Pedometers are provided that count the number of steps and display them on a display. The sensor detects walking by detecting changes in load due to weight movement during walking, but when walking on gravel roads, stairs, etc., the part of the footrest on which the weight is applied changes irregularly, so The sensor sometimes outputs noise other than the detection signal corresponding to the actual walking, which causes the sensor to count more steps than the correct number of steps, making it impossible to obtain the correct number of steps.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to remove noise other than the detection signal corresponding to walking from the output signal of the sensor, so that the correct number of steps can be counted. The purpose is to provide a step counter.

[Disclosure of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5. This is of the type that is attached to footwear 10, which is a so-called athletic shoe called sneakers, and includes a sensor 1, a mounting base 4 to which a lead wire 3 drawn out from the sensor 1 is directly connected, and this mounting base. The main body 2 is connected to the main body 4. The sensor 1 is attached to an insole 1 that is installed in footwear 10 and constitutes a footrest.
The main body 2 is installed in a space 7 formed in the shoe 1, and the main body 2 is detachably attached to the shoelace 12 portion of the footwear 10 via the mounting base 4. As shown in FIG. 2, the sensor 1 is composed of a pair of contact electrodes 9, 9 in the form of elastic flakes made of phosphor bronze, one in the form of a flat plate and the other in the form of a curved surface. When the curved contact electrode 9 is subjected to a load, the curved contact electrode 9 bends and conducts electricity by contacting the other contact electrode 9. In order to easily detect changes in load due to weight shift, the insole 11 is attached to the big toe of the foot. It is placed on the underside of the area from the ball of the foot to the base of the index finger. And this sensor 1 has protective cover 1
3 to make it waterproof. The main body 2 disposed on the mounting base 4 has a built-in button type battery as a power source, and a clear button 6 is provided on the side for resetting the display. It is equipped with a sheet fastener 8 as a fixture. When attaching to the footwear 10, the shoelace 12 is sandwiched between the planar fasteners 8. Note that the pedometer here is attached to only one of the pair of left and right footwear 10, and the sensor 1 detects walking by detecting a change in load when the footwear 10 touches the ground. , what is detected by the sensor 1 is simply the number of times one foot touches the ground, and the actual number of steps is a value obtained by doubling the detected number of times of ground contact. In addition, the sensor 1 is arranged in the insole 11 to make it easier to replace the sensor 1 and to make the sensor 1 less susceptible to various causes of deterioration. Furthermore, in addition to the sensor 1 consisting of a pair of contact electrodes 9 that contact each other under load, a strain gauge, a piezoelectric element, or the like may also be used.

Next, processing of the output signal from the sensor 1 will be explained.

FIG. 3 is a block diagram of the processing circuit, in which the output signal from sensor 1 is transmitted to selection circuit 15 and comparison circuit 1.
6, the counting circuit 18 counts the number of steps n, and the arithmetic circuit 19 doubles the number of steps n and converts it to the number of steps N taken with both feet, which is displayed on a display 20 made of liquid crystal. will be displayed.

The selection circuit 15 selects the signal with the maximum pulse width t _a from among the signals output from the sensor 1 within a predetermined time period Ts. For this purpose, a timer 21 is connected to the selection circuit 15. The timer 21 is activated when the output signal of the sensor 1 rises and operates for a predetermined time Ts, during which the selection circuit 15 selects the maximum pulse width t _a .

Then, the selection circuit 15 calculates the pulse width t of the output signal of the sensor 1 using a pulse width measuring means and a timer 2.
and selecting means for selecting the maximum pulse width t _a from among the pulse widths t measured by the pulse width measuring means within the predetermined time Ts defined in 1.

The pulse width measuring means is a known technical means prior to the filing of the present application, such as "Fundamentals and Applications of Pulse Measurement <Electronic Science Series" (published by Sanpo Co., Ltd. on October 30, 1981),
It is sufficient to apply the technique of "Pulse Width Measurement Using Integral Technology" described in pages 123 to 129 of Hideo Yamanaka), and the above selection means can be applied to this pulse width measurement means. The maximum pulse width data is selected from among the pulse width data measured by the pulse width data, and this selection process may be configured by a programmed microcomputer. This selection means is a technical means known before the filing of the present application, such as "Special Collection of BAIC Programs Utilizing Sharp MZ-80B" (January 10, 1980, published by Gakken Co., Ltd., written by System House P&P Microcomputer Research Group)
It may be configured by a microcomputer that stores a program for selecting the maximum value from a plurality of input data as described on page 52 of . In this way, the selection circuit 15 is constructed by combining the pulse width measuring means and the selection means.

The timer 21 starts operating from the rising edge of the output signal of the sensor 1, and the selection circuit 15 also starts selection at the same time. First of all,
The selection circuit 15 selects the pulse width t of the output signal of the sensor 1.
(pulse width measuring means), and if this pulse width t is smaller than the predetermined time Ts and is the first pulse, this pulse width t is memorized as t _a , and when the next pulse width t is measured, it is the same as the previous pulse width t. It compares with the stored t _a and if t > t _a , replaces t _a with a new t and stores it (selection means). This operation is continued until the predetermined time Ts set by the timer 21 has elapsed, and when the predetermined time Ts has elapsed, the stored pulse width t _a reaches its maximum value. As a result, the signal with the largest pulse width among the signals output from the sensor 1 within the predetermined time Ts set by the timer 21 is selected. Then, compare this t _a with the comparison circuit 1
Output to 6. Here, since the number of steps per second when a human runs the fastest is 5, the predetermined time Ts is calculated as 2.5 steps per second when converted to the number of steps per second when running on one foot. Since the period of the output signal of the sensor 1 corresponding to walking is 400 msec or more, Ts is set as 400 msec. Then,
The maximum pulse width ta selected by the selection circuit 15
It is expected that the signal corresponds to walking, but the comparator circuit 16 further compares the pulse width ta of this signal.
is compared with a predetermined pulse width Ta, and only when the pulse width ta is greater than or equal to the predetermined pulse width Ta, it is regarded as a signal corresponding to walking, and the counting circuit 18 counts it as the number of steps n. For this reason, a signal corresponding to the predetermined pulse width Ta stored in the memory circuit 17 is inputted to the comparison circuit 16, and the comparison circuit 16 inputs a signal corresponding to the predetermined pulse width Ta stored in the storage circuit 17. A signal is output to the counting circuit 18 when the width is greater than or equal to Ts. Here, the predetermined pulse width Ta is the time during which the feet are in contact with the ground when a human runs at the fastest speed.
Since it is 100msec or more, Ta=100msec. Figure 4 shows the output signal of the sensor 1 when walking on a gravel road, stairs, etc. As is clear from this figure, a signal that is considered to be noise is generated due to the chattering of the pair of contact electrodes 9, 9 of the sensor 1. There is. As shown in FIG. 4, since the maximum pulse width ta ₂ within the predetermined time Ts from the rise of the second output signal is smaller than the predetermined pulse width Ta, no signal is output from the comparator circuit 16 to the counting circuit 18; The signal is considered to be noise other than the detection signal corresponding to walking and is removed, and the counting circuit 18 does not count this signal. In addition, signals other than the maximum pulse width ta ₃ within the predetermined time Ts from the rise of the third output signal are also removed as noise other than the detection signal corresponding to walking, so only the detection signal corresponding to actual walking is removed. The correct number of steps is counted and displayed on the display 20. Even when the pedometer of the present invention is disposed on the footrest of footwear and the sensor is composed of a pair of contact electrodes, strain gauges, piezoelectric elements, etc., even when walking on gravel roads, stairs, etc. It can accurately count the number of steps.

Incidentally, the sensor 1 may be a known sensor that outputs a signal corresponding to the walking as the user walks other than the embodiments described above.

〔Effect of the invention〕

As described above, the present invention includes a sensor that outputs a signal corresponding to walking, a timer that operates and stops for a predetermined time from the rising edge of the output signal of the sensor, and starts operating again at the rising edge of the next output signal. a selection circuit that selects a signal with a maximum pulse width among the signals outputted by the sensor within a predetermined time when the timer operates in response to the output signal of the sensor; It comprises a comparison circuit that compares a stored predetermined pulse width and outputs a signal only when the pulse width is greater than or equal to the predetermined pulse width, and a counting circuit that receives the output signal of the comparison circuit and counts the number of steps. In the selection circuit and the comparison circuit, signals other than the detection signal corresponding to walking are considered as noise and removed, and the counting circuit does not count this signal, so that the correct number of steps can be counted.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a sectional view of the same, FIG. 3 is a block circuit diagram of the same, and FIG. 4 is a time chart of the sensor output signal of the same.
FIG. 5 shows a flowchart of the processing operation of the sensor output signal same as above. 1... Sensor, 10... Footwear, 11... Insole (foot rest), 15... Selection circuit, 16...
Comparison circuit, 18... counting circuit.

Claims (1)

[Scope of Claims] 1. A sensor that outputs a signal corresponding to walking, and a timer that operates and stops for a predetermined time from the rising edge of the output signal of the sensor, and starts operating again at the rising edge of the next output signal; a selection circuit that selects a signal with the largest pulse width among the signals output by the sensor within a predetermined time period during which the timer operates in response to the output signal of the sensor; A comparison circuit that compares a stored predetermined pulse width with a pulse width and outputs a signal only when the pulse width is greater than or equal to the predetermined pulse width, and a counting circuit that receives the output signal of the comparison circuit and counts the number of steps. A pedometer featuring: 2. The pedometer according to claim 1, wherein the sensor is provided only on one of the pair of footwear.