KR100972821B1 - Golf club sensing device and virtual golf simulation device using the same and golf club sensing method - Google Patents

Abstract

PURPOSE: A club sensing device, a virtual golf simulation apparatus using the same, and a golf club sensing method are provided, which can measure the absolute position, and can be manufactured thinly and lightly, and can be embodied with an affordable price. CONSTITUTION: A putting simulator accepting a golf club sensing device includes: a sensor coil array(20) formed with a plurality of coils and installed in a golf mat; a sensor sensing the change of signal accompanied by the golf club getting near to the corresponding coil by adding voltage to each coil according to an approved pulse, wherein the sensor is connected to each coil of the sensor coil array; and a sensor circuit part(30) including a controller presuming parameter about the movement property of the golf club by receiving the signal sensed from each sensor and approving a pulse to each sensor.

Description

GOLF CLUB SENSING DEVICE AND VIRTUAL GOLF SIMULATION DEVICE USING THE SAME AND GOLF CLUB SENSING METHOD}

The present invention relates to a golf club sensing device, a virtual golf simulation device and a golf club sensing method using the same, and more particularly, a golf club for measuring the characteristics of the position and speed, angle and hitting point of the golf club during the golf swing The present invention relates to a sensing device, a virtual golf simulation device, and a golf club sensing method using the same.

In general, golf is a sport that hits a golf ball with a golf club to hole in a hole cup. Therefore, there have been various attempts to grasp the characteristics of a golf swing because it must hit a small golf ball accurately and adjust an accurate distance.

In particular, it is important to accurately sense the behavior of the golf club during the golf swing for the virtual golf game through the virtual golf simulation.

Conventionally, optical sensors, image sensors, inertial sensors, radar sensors, and the like have been used to sense the behavior of golf clubs.

The optical sensor is a method of receiving and sensing the light reflected by the golf club blocking the path through which the light passes, and the image sensor is a method of sensing the change of the image acquired by capturing the behavior of the golf club during the golf swing. The inertial sensor, especially the acceleration sensor, is mounted on a golf club to sense the acceleration of the golf club during a golf swing, and the radar sensor measures the reflected wave through a radar.

However, the optical sensor has a problem such as the cost-effectiveness of the installation should be installed so as not to interfere with the golf club passing because the golf sensor must be installed in the path that the golf club passes during the golf swing, the image sensor is expensive camera device for accurate sensing There is a problem that must be used, the acceleration sensor is difficult to avoid the drift error due to the integration, the radar sensor has a problem such as the increase in the size and cost of the equipment according to the generation and measurement of high-frequency signals.

The present invention can sense the absolute characteristics of the golf club by using the magnetic induction phenomenon, and unlike the inertial sensor can measure the absolute position without requiring an optical path, it can be made thin and light, and can be implemented at low cost To provide a golf club sensing device, a virtual golf simulation device and a golf club sensing method using the same.

Golf club sensing device according to the present invention, the golf club sensing device for sensing the swing characteristics of the golf club, the sensor coil array formed by a plurality of coils installed on the golf mat; And a sensor circuit unit connected to the sensor coil array and applying a pulse to each coil, and estimating a parameter relating to a movement characteristic of the golf club from a signal output as the golf club passes the sensor coil array.

Also preferably, the sensor coil array may be formed such that a plurality of coils are formed in a direction crossing the golf mat.

Also preferably, the sensor circuit is embedded in the golf mat is characterized in that it is provided.

Also preferably, the sensor circuit is characterized in that it is provided to be embedded in the case provided on one side of the golf mat.

Also preferably, the sensor circuit unit may include a plurality of sensing units connected to respective coils of the sensor coil array to generate a change in a signal as the golf club approaches the coil, and apply pulses to the plurality of sensing units, respectively. And a controller for receiving an output signal from each of the sensing units and estimating a parameter relating to a movement characteristic of the golf club.

Also preferably, the sensor circuit unit may further include a switching unit for extracting a signal of a specific range of the output signals from the respective sensing units.

Also preferably, the switching unit may include a plurality of switches connected to each of the sensing units and selectively connected to each other by the control unit.

Also preferably, the sensor circuit unit may further include a signal amplifier for amplifying the signal passing through the switching unit, and a filtering unit for removing noise of the amplified signal. Characterized in that converted to a signal.

On the other hand, the virtual golf simulation apparatus according to the present invention, a golf mat; A sensor coil array formed by a plurality of coils installed on the golf mat; A sensor circuit unit connected to the sensor coil array and applying a pulse to each coil, and estimating a parameter relating to a movement characteristic of the golf club from a signal output as the golf club passes the sensor coil array; A host for receiving data from the sensor circuit unit and simulating a trajectory of a golf ball according to a golf swing; And an image processor configured to process the virtual golf simulation image by the data received from the host.

Also preferably, the sensor circuit unit may include a plurality of sensing units connected to respective coils of the sensor coil array to generate a change in a signal as the golf club approaches the coil, and among the output signals from each sensing unit. A control unit for applying a pulse to each of the plurality of sensing units and extracting a signal of a specific range, and receiving a signal extracted from the switching unit, estimating a parameter relating to a movement characteristic of a golf club and transmitting it to the host. It is characterized by including.

On the other hand, the golf club sensing method according to the present invention, in the golf club sensing method for sensing the swing characteristics of the golf club, (A) applying a pulse to each of the plurality of coils constituting the sensor coil array; And (B) estimating a parameter relating to a movement characteristic of the golf club from the signal output as the golf club passes the sensor coil array.

Also preferably, a plurality of sensing units connected to each of the coils to generate a change in a signal as the golf club approaches the coil is provided, and the step (A) may include applying a pulse to the sensing unit, and applying And applying a voltage to the coil connected to the sensing unit during the given pulse width.

Also preferably, the step (B) may include detecting and outputting a current of a corresponding coil induced when the pulse applied to the sensing unit ends.

Also preferably, the step (B) is characterized in that it comprises the step of extracting a signal of a specific range of the signal output by the output step.

Also preferably, the step (B) may include amplifying the signal extracted in the signal extraction step, filtering to remove noise of the amplified signal, and converting the filtered signal into a digital signal. And a sampling step.

Also preferably, the step (A) includes a step of sequentially applying pulses to the plurality of sensing units, and the step (B) processes the signals sequentially output to the plurality of sensing units. Characterized in that it comprises a step.

In addition, preferably, the step of initially receiving the output of each detection unit at least once or more to calculate and store the average value, and measuring the output of each detection unit according to the swing of the golf club to calculate the difference value with the stored average value And calculating the sum of the difference values, and when the sum is equal to or greater than the first preset value, the sensor enters a sensing state and stores an output value. It characterized in that it comprises the step of transmitting to the host.

The golf club sensing device, the virtual golf simulation device, and the golf club sensing method using the same according to the present invention do not require an optical path by sensing the behavior characteristics of the golf club by using a magnetic induction phenomenon, unlike an inertial sensor. It can measure, and because the sensor terminal is arranged in a relatively small number of coils can be made thin and light, there is an effect that can be implemented at a low cost.

1 is a diagram showing a case where a golf club sensing device according to an embodiment of the present invention is applied to a putting simulator.
2 is a view showing a golf club sensing device according to an embodiment of the present invention is applied to a putting simulator of another example.
3 (a) and (b) is a view showing a measurement parameter according to the movement characteristics of the putter golf club sensing apparatus according to the embodiment shown in FIG.
4 is a block diagram illustrating the golf club sensing device shown in FIG. 1 in more detail.
5 is a view showing in more detail the configuration of the sensing unit of the golf club sensing device shown in FIG.
FIG. 6 is a diagram schematically illustrating signal waveforms of respective parts illustrated in FIG. 5.
FIG. 7A is an actual example of the signal waveform of part (D) of FIG. 5, and FIG. 7B is an enlarged view of a part of the signal waveform shown in (a) above.
8 is a flowchart showing the flow of work performed by the controller in the golf club sensing device shown in FIG. 4.
9 shows an example of an IxN matrix C (i, n) transmitted from a control unit to a host.
10 to 14 are diagrams respectively showing images and graphs of measured values for each parameter defined in FIG. 3.

An embodiment of a golf club sensing device, a virtual golf simulation device using the same, and a golf club sensing method according to the present invention will be described in more detail with reference to the accompanying drawings.

Golf club sensing device according to the present invention is basically installed on the golf mat is provided to sense the movement characteristics of the golf club passing on the golf mat as the swing to the golf club on the golf mat.

Such a golf mat may be a golf mat provided on a swing plate of a virtual golf simulation apparatus, a golf mat as a component such as a simple golf simulator or a portable golf simulator, or a putting mat as a component of a putting simulator. .

First, a case in which a golf club sensing device according to an embodiment of the present invention is applied to a putting simulator will be described with reference to FIG. 1.

The putting simulator to which the golf club sensing device is applied according to an embodiment of the present invention has a putting mat 10, a golf club sensing device 20 and 30, a host 3 and an image processing means 4 as shown in FIG. 1. ) And the like.

Here, the golf club sensing devices 20 and 30 are installed on the putting mat 10 and the golf club sensing device is connected to the host 3.

The host 3 is a main processing apparatus for processing the putting simulation data, and the image processing means 4 is an image such that the putting simulation image is implemented in a predetermined display means based on the data processed by the host 3. Contains components to process.

On the other hand, the golf club sensing device comprises a sensor coil array 20 and the sensor circuit unit 30.

As shown in FIG. 1, the sensor coil array 20 is preferably embedded in the putting mat 10. The plurality of sensor coil arrays 20 are arranged in a direction substantially perpendicular to the advancing direction of the putter 2 on the putting mat 10. Preferably, the coils are arranged at predetermined intervals. That is, the sensor coil array 20 may be formed by arranging a plurality of coils in a direction crossing the putting mat 10.

In addition, as shown in Figure 1, the sensor coil array 20 is preferably disposed more toward the golf club (putter 2) than the position of the golf ball 1 (position before being hit by the golf club). .

That is, the sensor coil array 20 should be disposed so that the putter 2 may hit the golf ball 1 by passing through the sensor coil array 20.

Meanwhile, the sensor coil array 20 is connected to the sensor circuit unit 30, and the sensor circuit unit 30 is also embedded in the putting mat 10 as shown in FIG. 1.

The sensor circuit unit 30 applies a pulse to each coil of the sensor coil array 20 and relates to the movement characteristics of the putter 2 from a signal output as the putter 2 passes the sensor coil array 20. Estimate the parameter.

Meanwhile, FIG. 2 illustrates a case in which a golf club sensing device according to an embodiment of the present invention is applied to another putting simulator. In the embodiment shown in FIG. 2, a golf club sensing device is embedded in the putting mat 10. The case is provided on one side of the putting mat 10. Other matters are the same as the above-described embodiment shown in FIG.

3 (a) and 3 (b) show parameters relating to the motion characteristics of the golf club (putter 2). The putter passing through the sensor coil array 20 as shown in FIG. (2) forward speed (Vx), striking point (position of the center point of the putter (2) relative to the reference position (O), l) putter surface angle (θy) and the like, as shown in (b) of FIG. Parameters such as the distance h between the putter 2 and the bottom surface and the putter slope θr are estimated.

Golf club sensing device according to an embodiment of the present invention basically when each of the coil (20a ~ 20f) to apply a pulse to each coil (20a ~ 20f) of the sensor coil array 20, as shown in Figure 3 (a) Each parameter as described above is estimated by determining the proximity of the golf club made of a conductor based on the tendency of the current to increase and decrease in 20f).

That is, when the golf club is in close proximity to the coil, when the coil's magnetic field changes, a eddy current is generated inside the conductor golf club, which in turn causes a change in the current reduction form of the coil. By arranging such coils in a row in a row, the golf clubs can be placed inside a passing mat and various parameters can be determined by continuously measuring the change as the golf club passes.

Here, each coil generates a signal proportional to the proximity of the golf club. When the putter 2 passes as shown in FIG. 3 (a), a large signal is generated in the coils 20c and 20e located at the center. A small signal is output from the coils 20a, 20f, etc. located in the vicinity.

As the putter 2 passes, measurements are made by each coil 20a to 20f at a rapid cycle. When the number of coils is I and the number of measurements is made N times, as a result, an IxN matrix is obtained. Can be estimated.

On the other hand, with reference to Figure 4 will be described a more specific configuration regarding the golf club sensing device according to an embodiment of the present invention.

As shown in FIG. 4, each of the coils 20a to 20f constituting the sensor coil array is connected to a sensor circuit unit. The sensor circuit unit includes a plurality of sensing units d1 to d6, a switching unit 40, and a signal. The amplifier 50, the filtering part 60, the control part M, etc. are comprised.

In FIG. 4, a case in which six coils and sensing units are illustrated is illustrated, but the present invention is not limited thereto, and a plurality of coils and sensing units are included.

Each sensing unit d1 to d6 is connected to each of the coils 20a to 20f as shown in FIG. 4, and receives a pulse input from the control unit M to apply a voltage to each of the coils 20a to 20f and play golf. The change in signal occurs as the club approaches the coil.

The signal output from each of the sensing units d1 to d6 is connected to the switching unit 40 to extract the signal, and is connected to the signal amplifier 50 and the filtering unit 60.

The control unit M receives a pulse from each of the sensing units d1 to d6 and receives a signal output from each of the sensing units d1 to d6 and transmits the signal to the host 3 when a predetermined condition is satisfied.

That is, each of the sensing units d1 to d6 applies a voltage to the coils 20a to 20f during the pulse width when the pulse input is received from the control unit M, and detects and outputs the current of the coil induced when the pulse ends.

The controller M sequentially transmits pulses to the sensing units d1 to d6 and operates each switch 40a to 40f of the switching unit 40 to receive the response of the corresponding sensing unit to perform A / D conversion to host 3. Send to.

The output of the sensing unit passes through the switching unit 40, amplified by the signal amplifier 50, filtered by the filtering unit 60, and input to the A / D conversion input pin of the controller.

Meanwhile, one of the sensing units shown in FIG. 4 will be described in more detail with reference to FIGS. 5 to 7.

A portion indicated by a dotted line in FIG. 5 corresponds to any one of the sensing units d of the plurality of sensing units d1 to d6 illustrated in FIG. 4, and thereafter, the switching unit 40 and the signal amplifier 50. , The filtering unit 60 and the like are shown together for explanation.

 FIG. 6 shows signal waveforms of the main part shown in FIG. When a pulse signal as shown in (A) is given as an input to the sensing section, the current of the coil of the sensing section starts to increase as shown in (B) during the sustaining period of the pulse. At the end of the pulse period, the switch of the sensing section (one switch constituting the switching section) is opened and the current flowing in the coil continues to flow along the surrounding resistors and diodes and decreases exponentially as shown in (B).

The voltage in part (C) of FIG. 5 is maintained at VCC while the switch is closed, but the reverse voltage is generated as shown in (C) of FIG. Decreases exponentially as

In the waveform of FIG. 6D, the waveform of (C) is limited by the diode clamp. The exponentially decreasing portion of the waveform shown in (D) is affected by the presence or absence of a conductor near the coil. The proximity of nonmagnetic conductors causes the exponential decline to be slower than usual, resulting in thicker exponential tails.

The golf club sensing device according to the present invention detects such a change, so that the proximity of the golf club, that is, the proximity of the conductor, should be measured by separating the tail.

For this purpose, only the tail portion is cut as shown in FIG. 6E using the switching unit shown in FIG. 5. This part of the signal usually has a low value of less than 0.1V, so amplification is required and filtering is required to reduce the influence of noise. An example of the amplified and filtered signal is shown in FIG. The controller then samples the value near the highest point of this waveform.

FIG. 7 is a measurement example of the signal waveform in part (D) of FIG. 5. When the VCC is 5V, the input pulse width is 10us, and the coil inductance is 400uH, the waveforms measured by varying the distance between the conductor and the coil to 1cm, 2cm, 3cm, and 4cm are superimposed.

The part showing the change according to the distance is the tail part of the exponential decrease section, and FIG. 7 (a) shows the entire signal waveform, and FIG. 7 (b) shows the difference by distance by enlarging the tail part. Giving. In (b) of FIG. 7, the uppermost waveform corresponds to the case where the conductor is farthest, and conversely, the lowest waveform corresponds to the case where the conductor is nearest.

On the other hand, with reference to Figure 8 will be described the flow of work performed by the control unit of the golf club sensing apparatus according to an embodiment of the present invention shown in FIG. Here, a case of detecting the movement characteristic of the putter on the putting mat as shown in FIG. 1 or 2 will be described as an example.

Since the plurality of sensing units d1 to d6 illustrated in FIG. 4 may show slight differences for the same pulse input, they need to be compensated for. In other words, in order to compensate for the individual differences of the plurality of sensors, the output of each detector at the beginning of the program x (i, n) (i = 1, 2, ..., I, I is the number of detectors, n is the time sample index ) Is read K times to calculate the average value Xm (i) (S10). That is, Xm (i) is defined as in Equation 1 below.

Xm (i) = sum_ {n = 1} ^ {K} {x (i, n)} .......... (Equation 1)

After that, the measurement of the output X (i, n) of each sensing unit is repeated (S20). Considering the general speed range of the putter, a sample period of about 1 ms is required, and each sensing unit takes about 100 us. It is not easy to transfer data every sample.

Therefore, the controller measures the output X (i, n) of the detector and calculates a difference value from the previously stored reference value Xm (i) (S30). Here, the difference value C (i, n) is defined as in Equation 2 below.

C (i, n) = X (i, n)-Xm (i) ............... (Equation 2)

Every time S (n) = sum_i C (i, n), which is the sum of C (i, n), is calculated (S50), and when S (n) is above a predetermined level, that is, above a predetermined set value S1 (S70) " (S71) While in the “detected” state, the controller continuously stores the measured value in the ring buffer each time (S40).

If S (n) is below a certain level, i.e., below the preset setting value S2 (where S2 <S1) (S60), the control unit transmits all the samples stored in the ring buffer to the host so far and exits from the “detected” state. (S61, S62).

As a result, every time the putter passes over the sensor, the microcomputer sends an IxN matrix c (i, n) (i = 1, 2, ..., I, n = 1, 2, ..., N) to the host. .

On the other hand, four images respectively shown in (a), (b), (c) and (d) of Figure 9 shows an example of the IxN matrix c (i, n) transmitted from the control unit to the host.

(A) of FIG. 9 shows that the putter passes exactly in the forward direction, and FIG. 9 (b) shows the same as the case of (a) above, but when the distance from the bottom is greater, FIG. 9 (c) shows the putter. In the case where the face of is passed obliquely, Figure 9 (d) is the same as the case of (a), but shows an example of the case where the bottom of the putter is not horizontally passed.

The horizontal direction of the image is the time axis (n) and the vertical direction is the index (i) axis of the sensor coil. In the example of FIG. 9, the number i of the detectors is 6 and the time sample index n is 250. The brightness of each pixel in the image represents the value of the matrix as shown in the right palette.

On the other hand, from the IxN matrix c (i, n), the parameters defined in Fig. 2, namely, the forward speed Vx of the putter, the hitting point l, the angle of the putter surface θy, the distance between the putter and the bottom surface h, A process of estimating the slope θr and the like will be described.

FIG. 10A shows sensor values c (i, n) obtained when the gap between the putter and the bottom surface is three. Under the assumption that the putter is not within the range of six coils, the spacing h between the putter and the bottom is related to the sum of the outputs of the coils.

Thus, S (n) = sum_i c (i, n), which is the sum of the outputs of all coils, was obtained, and the maximum value of S (n), S_max = max_n {S (n)}, was obtained as shown in FIG. .

The difference between the height of the putter and the bottom surface (h), i.e., S_max, can be estimated by considering how the strength of the magnetic field varies with the distance from the coil.

For finite diameter coils, the magnetic field decreases with increasing distance, which decreases almost linearly in the region comparable to the radius of the coil and as farther away as shown in Equation 4 below. . In this case, the radius of the coil is 1 and the distance is z.

1 / (z ^ 3 + 1.5z) ... (Equation 4)

Because the output of the sensing device is generally proportional to the eddy currents and the eddy current is proportional to the magnetic field, it can be expected that the output of the sensing device will generally have this tendency.

FIG. 10 (b) shows the relationship between S_max (maximum sum of outputs of all coils) values for the three heights shown in FIG. 10 (a).

The exact relationship between height and S_max depends on the actual coil type, circuit elements, and type of putter, so it must be determined through experiments.

That is, height = h (S_max), where h (x) is a function that can be determined through experiments.

11A is a sensing value obtained in the case of three speeds Vx. The pattern change with the speed of the putter is predictable.

The slower the signal, the longer the putter stays in the coil's range and the longer the signal appears.

That is, the time the signal is detected will be inversely proportional to the speed of the putter. To determine the detection time, S (n) finds the interval over a certain threshold and finds its length.

In the example shown in (a) of FIG. 11, the lengths of the run are 169, 89, and 60 for each speed, and the relationship of (1 / run) according to the speed Vx is summarized in (b). Considering that 1 / run will be 0 when the velocity is 0, we can see that three points are generally located on a straight line starting from the origin.

The run value thus obtained is influenced by the threshold for distinguishing the presence of a signal. Even if the speed of the putter is constant, the run will be small if the signal is small overall, and the run will be large if the signal is large overall.

This problem will not be significant when the threshold is small, but in reality, it is difficult to avoid this problem because the threshold must be kept above a certain level to avoid the influence of noise.

Therefore, this run needs to be corrected according to the height value obtained earlier. Including this correction, the speed of the putter can be estimated using a model according to Equation 5 below.

Vx = Vxo * / f (height) * run ............. (Equation 5)

Where Vxo is a constant and f (x) is a function for correcting run by height. The smaller the height, the larger the signal, and if the signal is large enough, no correction is necessary, so f (x) should be 1 when height is 0 and increase as height increases, and the exact shape should be determined by experiment. do.

On the other hand, Fig. 12A is a sensing value obtained when the impact point (measured by the distance l from the reference position O shown in Fig. 2A, offset) is four offsets.

In all four cases shown in (a) of FIG. 12, the putter was moved at almost the same speed, and the putter was horizontally moved (actually, the sensor was horizontally moved). In order to estimate the offset value, the signal value C (i) = sum_n c (i, n) for each coil was calculated by adding the values along the time axis and is shown in FIG.

In Figure 12 (a) it can be seen that the center of gravity of the signal moves up and down, which is represented by the horizontal movement in Figure 12 (b). As the offset increases, the center of the curve changes from right to left. Therefore, it is necessary to find the center of the curve, in which case the center of gravity can be used. When the center of gravity is called Cm, the center of gravity Cm can be expressed by the following equation.

Cm = (sum_i {C (i) * i}) / (sum_i {C (i)}) ..... (Equation 6)

12 (c) shows the change of Cm according to the offset. In the example shown in FIG. 12C, the center of gravity Cm is 4.9299, 3.6370, 2.5604, and 1.9281 depending on the offset. In this experiment it was measured while moving by about 25mm.

Since the spacing between the coils is about 30mm, it can be expected that the ratio of the offset to the coil number will be close to one. In practice, the sum of the signal magnitudes will be relatively reduced as we move away from the center of the sensor, so we will not have a precise linear relationship, but we can consider the model given by Eq. Where alpha is an experimentally determinable constant.

offset = alpha * Cm ............... (Equation 7)

Meanwhile, FIG. 13A illustrates yaw values for five putter surface angles (θy and yaw shown in FIG. 2). If yaw is 0, a symmetrical pattern is obtained as in the third graph of (a), while if yaw is tilted in the negative direction, a pattern is tilted to the right as in the first and second graphs, and yaw is positive. Tilt in the direction of gives a pattern that tilts to the left as shown in the fourth and fifth graphs.

For example, in the case of the first graph of (a) of FIG. 13, when the putter first enters the coil 6, the lower coil is activated first. The yaw may be estimated from the time difference between the adjacent coils, but there may be a difference in sensitivity depending on the coil, and above all, even when yaw is zero due to the effect of the putter slope θr not being zero. This active time difference can occur.

Therefore, it is more reliable to estimate yaw using the shift of the center of the activated time without using the time at which it starts to be activated.

FIG. 13B is obtained by the following Equation 8, which is the time center of the output value of each coil.

nc (i) = (sum_n {c (i, n) * n}) / (sum_n c (i, n)) .... (Equation 8)

It is clear that the nc value of each coil has a linear relationship with the coil position. If yaw is 0, the nc of all the sensors have almost the same value, and if yaw is 20 degrees, it can be seen to increase linearly with the coil number.

Since the linear constant is proportional to yaw, linear regression can be used to obtain the linear constant. However, since the number of data represented by each nc is different, it is necessary to use weighted linear regression.

For example, in case of coil 1, the signal value is weak, so if you find the center nc of this signal, it becomes meaningless value determined by noise. In FIG. 13B, the value of the first sensor has a meaningless value outside the graph range. If we treat these points as equal weight, we cannot get meaningful proportionality.

Therefore, for each curve of Fig. 13 (b), the proportional constant can be obtained by taking the specific signal value of each coil as the specific gravity, and the result is -7.2664, -3.8861, 0.1916, 4.3635, and 6.9107 in this example, respectively. As shown, it is proportional to yaw.

Based on these results, we can consider the following model for estimating yaw. First, C (i), which is the sum of signals per coil, and the time center value nc (i) of the signals for each sensor are obtained, and a proportional coefficient ay between i and nc is obtained using weighted linear regression. Here we use C (i) as the weight. The calculated ay and actual yaw follow Equation 9 below.

yaw = beta * ay / Vx ........... (Equation 9)

Where Vx is the velocity of the putter and beta is the experimentally determined constant. The reason for dividing by Vx is that in the case of yaw of the same value, there is an inverse relationship in which the difference between nc decreases as the putter speed increases.

FIG. 14A illustrates roll values for three putter slopes (θr and roll shown in FIG. 2). The graph shown in (a) of FIG. 14 is a case where the putter is tilted about 10 degrees toward the toe and the middle graph is as horizontal as possible, and the graph below shows the case where the putter is tilted about 10 degrees toward the heel.

The effect of the roll is that the coil-by-coil output is not symmetrical and is ubiquitous toward the upper or opposite coils.

In FIG. 14 (b), C (i) which is a signal of a coil-specific signal is calculated and shown as a graph. The green line is most symmetrical, the blue line is to the left and the red to the right.

Use the slope of the curve to quantify the bias. If the putter is tilted to the left, the value of the left coil is larger and the right coil is smaller. Therefore, the roll of the putter can be estimated by calculating the slope of the output of the coil under the putter.

The problem is that it is difficult to know which coil is under the putter, and if you use the values of all the coils, the estimate of the slope will be distorted. As a simple method for solving this problem, the slope is estimated using only a certain number of maximum values in C (i). In the case of this example, considering the size of the sensor and the putter, since at least four of the six sensors are affected by the putter, the slope is calculated using only the maximum of four C (i) values.

The result of calculating the slope ar by the linear regression method using only data indicated by an asterisk in FIG. 14B is shown in FIG. 14C.

The slopes in this example are -145, 26, and 117, respectively. It can be seen that roll and ar are proportionally related. Based on these results, in order to estimate the roll, we calculate C (i) which is the sum of the signals of each coil and select only the maximum four of them and calculate the proportional coefficient ar between them. And roll is estimated as in the following Equation 11.

roll = gamma * ar ............... (Equation 11)

Where gamma is a constant that can be determined experimentally.

1: golf ball, 2: putter
3: host, 4: image processing means
10: putting mat, 20: sensor coil array
30: sensor circuit part, 40: switching part
50: signal amplifier, 60: filtering unit
M: control unit

Claims (18)

In the golf club sensing device for sensing the swing characteristics of the golf club,
A sensor coil array formed by a plurality of coils installed on the golf mat; And
A sensing unit connected to each coil of the sensor coil array and applying a voltage to each coil according to an applied pulse to sense a change in a signal as the golf club approaches the coil, and applying a pulse to each sensing unit A sensor circuit unit including a control unit for receiving a signal sensed by each detection unit and estimating a parameter related to a movement characteristic of the golf club;
Golf club sensing device comprising a. The method of claim 1, wherein the sensor coil array,
Golf club sensing device, characterized in that a plurality of coils are arranged in a direction crossing the golf mat. The method of claim 1,
The sensor circuit unit is a golf club sensing device, characterized in that is provided embedded in the golf mat. The method of claim 1,
The sensor circuit unit is a golf club sensing device, characterized in that it is provided to be embedded in the case provided on one side of the golf mat. The method of claim 1,
The estimated parameter includes at least one of a forward speed of the golf club head passing through the sensor coil array, a hitting point of the golf club head, a golf club head face angle, a distance between the golf club head and the bottom face, and a tilt of the golf club head. Golf club sensing device, characterized in that. The method of claim 1, wherein the sensor circuit unit,
Golf club sensing device further comprises a switching unit for extracting a signal of a specific range of the output signal from each of the detection unit. The method of claim 6, wherein the switching unit,
Golf club sensing device, characterized in that provided with a plurality of switches connected to each of the sensing unit is selectively electrically connected by the control unit. The method of claim 6, wherein the sensor circuit unit,
Further comprising a signal amplifier for amplifying the signal passing through the switching unit, and a filter for removing the noise of the amplified signal,
And the control unit converts the amplified and filtered signals into digital signals. Golf mats;
A sensor coil array formed by a plurality of coils installed on the golf mat;
A sensing unit connected to each coil of the sensor coil array and applying a voltage to each coil according to an applied pulse to sense a change in a signal as the golf club approaches the coil, and applying a pulse to each sensing unit A sensor circuit unit including a control unit for receiving a signal sensed by each detection unit and estimating a parameter related to a movement characteristic of the golf club;
A host for receiving data from the sensor circuit unit and simulating a trajectory of a golf ball according to a golf swing; And
An image processor configured to process a virtual golf simulation image based on the data received from the host;
Virtual golf simulation device comprising a. The method of claim 9, wherein the sensor circuit unit,
A plurality of sensing units connected to each coil of the sensor coil array to generate a change in a signal as the golf club approaches the coil,
A switching unit for extracting a signal of a specific range of the output signal from the respective sensing unit, and applying a pulse to each of the plurality of sensing unit, and receives the signal extracted from the switching unit to determine the parameters of the movement characteristics of the golf club Virtual golf simulation apparatus comprising a control unit for estimating and transmitting to the host. In the golf club sensing method for sensing the swing characteristics of the golf club,
Applying a pulse to a sensing unit connected to each of the plurality of coils constituting the sensor coil array and detecting a change in a signal as the golf club approaches the coil;
Applying a voltage to a coil connected to the sensing unit during the pulse width applied to the sensing unit; And
Estimating a parameter relating to a movement characteristic of the golf club from the signal output from the detection unit;
Golf club sensing method comprising a. The method of claim 11, wherein estimating the parameter comprises:
At least one of a forward speed of the golf club head passing through the sensor coil array, a hitting point of the golf club head, an angle of the golf club head surface, a distance between the golf club head and the bottom surface, and an inclination of the golf club head from the signal output from the detector; Golf club sensing method comprising the step of estimating one. The method of claim 11, wherein estimating the parameter,
And sensing and outputting a current of a corresponding coil induced when the pulse applied to the sensing unit ends. The method of claim 13, wherein estimating the parameter,
And extracting a signal having a specific range from the signals output by sensing and outputting the current of the corresponding coil. The method of claim 14, wherein estimating the parameter comprises:
Amplifying the extracted signal in the step of extracting the signal of the specific range;
Filtering to remove noise of the amplified signal;
And a sampling step of converting the filtered signal into a digital signal. The method of claim 11,
The applying of the pulse includes applying a pulse sequentially to the plurality of sensing units,
And estimating the parameter comprises processing signals sequentially output to the plurality of sensing units. The method of claim 16, wherein processing the sequentially output signals comprises:
Initially receiving the output of each detector at least once and calculating and storing the average value,
Calculating a difference value from the stored average value by measuring the output of each detection unit according to a swing of a golf club, and calculating a sum of the difference values;
And if the sum is greater than or equal to the first preset value, detects and stores an output value. If the sum is less than or equal to the preset second preset value, the output value is transmitted to the host while the sum is less than the preset second set value. How to sense a golf club. In the golf club sensing device for sensing the swing characteristics of the golf club,
A sensor coil array formed by a plurality of coils installed on the golf mat;
Pulse applying means for applying a pulse to each coil of the sensor coil array; And
Parameter estimating means for estimating a parameter relating to a movement characteristic of a golf club by determining a degree of proximity of a conductor by detecting a tendency of current to increase and decrease when a pulse is applied to each coil;
Golf club sensing device comprising a.

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