JP7560269B2 - FALL DETECTION DEVICE, MOBILE TERMINAL, COMMUNICATION DEVICE, AND FALL DETECTION PROGRAM - Google Patents

Description

This disclosure relates to a technology for determining when a mobile device owner has fallen onto water or the ground.

Patent documents 1 and 2 disclose technology that determines whether the owner of a mobile device has fallen while climbing a mountain, or whether the mobile device has fallen freely while climbing a mountain.

Here, in Patent Document 1, the acceleration sensor of the mobile device is used to determine that the owner of the mobile device has fallen while climbing a mountain when the time during which the angular velocity of the mobile device is a finite value is equal to or greater than a reference value (e.g., 0.7 seconds), while determining that the mobile device has fallen freely while climbing a mountain when the time during which the angular velocity of the mobile device is a finite value is shorter than the reference value (e.g., 0.7 seconds).

In Patent Document 2, the air pressure sensor of the mobile device is used to determine whether the mobile device's altitude descent rate is equal to or exceeds a predetermined threshold (e.g., a free fall threshold) and whether the mobile device's owner has fallen while climbing a mountain or whether the mobile device has fallen freely while climbing a mountain.

JP 2014-049065 A Patent No. 6510368 specification

By applying Patent Documents 1 and 2, it is possible to determine whether the owner of the mobile device has fallen onto the water or onto the ground, or whether the mobile device has fallen freely onto the water or onto the ground.

Here, it takes about 1 second for the holder of the mobile device to fall onto the water or onto the ground. On the other hand, it takes about 0.5 seconds for the mobile device to freely fall onto the water or onto the ground. And within a time period of about 1 second or about 0.5 seconds, it is necessary to determine and communicate whether the holder of the mobile device has fallen onto the water or onto the ground, or whether the mobile device has freely fallen onto the water or onto the ground.

However, in Patent Document 1, the acceleration sensor of the mobile device is used to determine whether the time during which the angular velocity of the mobile device is a finite value is equal to or greater than a reference value (e.g., 0.7 seconds), making it difficult to determine and communicate whether the owner of the mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within a time period of approximately 1 second or approximately 0.5 seconds.

In addition, in Patent Document 2, the air pressure sensor of the mobile device is used to determine whether the rate at which the mobile device is decreasing in altitude is equal to or greater than a predetermined threshold (such as a free fall threshold), so it is difficult to accurately determine and communicate within a time period of about 1 second or about 0.5 seconds whether the owner of the mobile device has fallen onto the water or the ground, or whether the mobile device has free fallen onto the water or the ground.

Therefore, in order to solve the above problem, the present disclosure aims to determine and communicate with high accuracy whether the holder of a mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within the time (approximately 1 second) that the holder of the mobile device falls onto the water or the ground, or within the time (approximately 0.5 seconds) that the mobile device falls freely onto the water or the ground.

To solve the above problem, the system determines whether the owner of the mobile device has fallen onto the water or onto the ground, or whether the mobile device has fallen freely onto the water or onto the ground, based on the magnitude of the acceleration of the mobile device and the magnitude of the parameters of the rotational motion of the mobile device.

When the mobile device owner falls onto the water or onto the ground, the acceleration of the mobile device is the combined acceleration of gravity and centrifugal acceleration, and there is a time when it becomes slightly smaller than 1G, and there is a time when the parameters of the rotational motion of the mobile device become larger due to the conversion of potential energy into rotational motion energy, regardless of the fact that there was no rotation before the mobile device owner fell.

On the other hand, when a mobile device falls freely onto the surface of water or the ground, the acceleration of the mobile device is the combined acceleration of gravity and inertia, and there is a time when it is 0G. In addition to the lack of rotation before the mobile device free falls, the parameters of the rotational motion of the mobile device only involve the conversion of potential energy into linear kinetic energy, and there is no time for them to increase due to the conservation of angular momentum.

And there is sufficient time remaining from the time when it is determined that the acceleration of the mobile device is small and that the parameters of the rotational motion of the mobile device are large until the time when the holder of the mobile device falls onto the water or onto the ground, or until the mobile device falls freely onto the water or onto the ground.

Specifically, the present disclosure relates to a fall determination device that includes an acceleration acquisition unit that acquires information on the acceleration of the mobile device and information on parameters of the rotational motion of the mobile device from an acceleration sensor of the mobile device, and a fall determination unit that determines whether the holder of the mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, based on the magnitude of the acceleration of the mobile device and the magnitude of the parameters of the rotational motion of the mobile device.

With this configuration, the acceleration sensor of the mobile device can be used to determine and communicate with high accuracy whether the mobile device's owner has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within the time it takes for the owner of the mobile device to fall onto the water or the ground (approximately 1 second) or within the time it takes for the mobile device to fall freely onto the water or the ground (approximately 0.5 seconds).

The present disclosure also provides a fall determination device, characterized in that the fall determination unit determines that the holder of the mobile device has fallen onto the water or the ground based on the magnitude of a parameter of the rotational motion of the mobile device being equal to or greater than a predetermined threshold within a time period in which the magnitude of the acceleration of the mobile device is equal to or less than a predetermined threshold.

With this configuration, it is possible to determine that the owner of the mobile device has fallen onto the water or onto the ground based on the fact that the acceleration of the mobile device is small and the parameters of the rotational motion of the mobile device are large. And because the acceleration of the mobile device, which is less susceptible to the influence of the shaking of the mobile device, is determined before the parameters of the rotational motion of the mobile device, which is more susceptible to the influence of the shaking of the mobile device, are determined, it is possible to avoid erroneously determining that the owner of the mobile device has fallen onto the water or onto the ground.

The present disclosure also provides a fall determination device, characterized in that the fall determination unit determines that the mobile device has freely fallen onto the water surface or the ground based on the magnitude of a parameter of the rotational motion of the mobile device being smaller than a predetermined threshold within a time period in which the magnitude of the acceleration of the mobile device is equal to or smaller than a predetermined threshold.

With this configuration, it is possible to determine that the mobile device has fallen freely onto the water or the ground based on the fact that the acceleration of the mobile device is small and the parameters of the rotational motion of the mobile device are small. Furthermore, because the acceleration of the mobile device, which is less susceptible to the influence of the mobile device's shaking, is determined before the parameters of the rotational motion of the mobile device, which is more susceptible to the influence of the mobile device's shaking, it is possible to avoid erroneously determining that the mobile device has fallen freely onto the water or the ground.

The present disclosure also provides a fall determination device, characterized in that the fall determination unit uses as input data the magnitude of the acceleration of the mobile device and the magnitude of a parameter of the rotational motion of the mobile device, and as training data bit values indicating that the holder of the mobile device has fallen onto the water or the ground and that the mobile device has freely fallen onto the water or the ground, and learns using the input data and the training data.

With this configuration, it is possible to determine with high accuracy whether the owner of the mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, simply by mechanically learning using training data for the parameters of the acceleration and rotational motion of the mobile device, without an engineer having to set a predetermined threshold value for the parameters of the acceleration and rotational motion of the mobile device.

The present disclosure also provides a fall determination device, characterized in that the acceleration acquisition unit acquires at least one of the following information on the parameters of the rotational motion of the mobile device: angular velocity, angular acceleration, angular momentum, time derivative of angular momentum, rotational energy, and time derivative of rotational energy.

With this configuration, by using any one or a combination of the angular velocity, angular acceleration, angular momentum, time derivative of angular momentum, rotational energy, and time derivative of rotational energy of the mobile device, it is possible to determine with high accuracy whether the owner of the mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground.

The present disclosure also provides a tipping determination device, characterized in that the tipping determination unit removes components of the ship's motion caused by waves on the water surface or noise components of the acceleration sensor from information on the acceleration of the mobile device and information on parameters of the rotational motion of the mobile device.

With this configuration, only the components of the ship's motion or the noise components of the acceleration sensor are removed from the information on the parameters of the acceleration and rotational motion of the mobile device, and only the components of the mobile device's owner's fall or the free fall of the mobile device are extracted, making it possible to determine with high accuracy whether the owner of the mobile device has fallen onto the water surface or the mobile device has fallen freely onto the water surface.

The present disclosure also relates to a mobile terminal that is equipped with the above-mentioned fall determination device.

With this configuration, the acceleration sensor of the mobile device can be used to determine and communicate with high accuracy whether the mobile device's owner has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within the time it takes for the owner of the mobile device to fall onto the water or the ground (approximately 1 second) or within the time it takes for the mobile device to fall freely onto the water or the ground (approximately 0.5 seconds).

The present disclosure also provides a mobile terminal that notifies a communication device that is closer to the mobile terminal than a predetermined distance or that has been previously configured to link with the mobile terminal that the holder of the mobile terminal has fallen onto water or the ground.

This configuration allows people in close proximity to or related to the mobile device owner to be notified early that the mobile device owner has fallen into water or on the ground.

The present disclosure also provides a mobile terminal that notifies the communication device, which is closer to the mobile terminal than the predetermined distance or has a preset link with the mobile terminal, of the location where the owner of the mobile terminal has fallen onto the water or ground.

This configuration allows the location where the mobile device owner falls onto the water or ground to be notified quickly to people nearby or related to the mobile device owner.

The present disclosure also provides a mobile terminal that notifies the communication device, whose distance from the mobile terminal is shorter than the predetermined distance or whose link with the mobile terminal is preset, of the current location of the mobile terminal until the holder of the mobile terminal falls onto the water or onto the ground.

With this configuration, even if the holder of the mobile device is unable to notify the location where the holder of the mobile device fell onto the water or ground when the holder falls onto the water or ground, the most recent location of the mobile device up until the holder of the mobile device fell onto the water or ground can be reliably notified to people close to or related to the holder of the mobile device.

The present disclosure also provides a communication device that warns the owner of a mobile terminal that has fallen into water or onto the ground, based on the fact that communication between the communication device and the mobile terminal has been interrupted after the mobile terminal notifies the owner of the mobile terminal that the distance between the communication device and the mobile terminal is shorter than the predetermined distance or that cooperation with the communication device has been preset, that the owner of the mobile terminal has fallen into water or onto the ground.

With this configuration, after the owner of the mobile device falls onto the water or onto the ground, based on the fact that the mobile device is unable to communicate underwater or is destroyed on the ground, it is possible to issue a highly accurate warning to people in close proximity to or related to the owner of the mobile device that the owner of the mobile device has fallen onto the water or onto the ground.

The present disclosure also provides a communication device that warns the holder of the mobile terminal that has fallen onto the water or the ground when the distance between the communication device and the mobile terminal becomes greater than the predetermined distance when the communication device is closer than the predetermined distance or when the mobile terminal is notified of the location where the holder of the mobile terminal has fallen onto the water or the ground from the mobile terminal whose communication device is closer than the predetermined distance or whose connection with the communication device has been preset.

With this configuration, after the holder of the mobile device falls onto the water or onto the ground, it is possible to warn people in close proximity to or related to the holder of the mobile device with a high degree of accuracy that the holder of the mobile device has fallen onto the water or onto the ground, based on the fact that the mobile device has been carried away on the water or moved away on the ground.

The present disclosure also provides a communication device that, when notified by the above-mentioned mobile terminal that is closer to the communication device than the predetermined distance or that has been previously configured to link with the communication device that the holder of the mobile terminal has fallen onto the water or onto the ground, issues a warning that the holder of the mobile terminal has fallen onto the water or onto the ground, and displays the latest location of the mobile terminal up until the holder of the mobile terminal fell onto the water or onto the ground.

With this configuration, even if it is not possible to obtain the location where the mobile terminal holder falls onto the water or ground when the mobile terminal holder falls onto the water or ground, it is possible to reliably warn and display to people in the vicinity or related to the mobile terminal holder that the mobile terminal holder has fallen onto the water or ground, and the latest location of the mobile terminal before the mobile terminal holder fell onto the water or ground.

The present disclosure also relates to a fall determination program for causing a computer to function as the above-mentioned fall determination device.

With this configuration, the acceleration sensor of the mobile device can be used to determine and communicate with high accuracy whether the mobile device's owner has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within the time it takes for the owner of the mobile device to fall onto the water or the ground (approximately 1 second) or within the time it takes for the mobile device to fall freely onto the water or the ground (approximately 0.5 seconds).

In this way, the present disclosure can determine and communicate with high accuracy whether the holder of the mobile device has fallen onto the water or the ground, or whether the mobile device has fallen freely onto the water or the ground, within the time it takes for the holder of the mobile device to fall onto the water or the ground (approximately 1 second), or within the time it takes for the mobile device to fall freely onto the water or the ground (approximately 0.5 seconds).

1 is a diagram showing the configuration of a fall determination system according to the present disclosure. 11 is a diagram showing a procedure of a fall determination process according to the present disclosure. 11A and 11B are diagrams showing simulation results of the change over time in the angle of toppling, the angular velocity, and the acceleration of a mobile terminal when the holder of the mobile terminal falls over. 11A and 11B are diagrams illustrating simulation results of the acceleration, angular velocity, and temporal change in angular acceleration of a mobile terminal when the holder of the mobile terminal falls over. 11A and 11B are diagrams showing simulation results of changes in acceleration, angular momentum, and rotational energy of a mobile terminal over time when the holder of the mobile terminal falls over. 11A and 11B are diagrams showing experimental results of the acceleration, angular velocity, and temporal change in angular acceleration of a mobile terminal when the holder of the mobile terminal falls over. 11A and 11B are diagrams showing experimental results of changes in acceleration, angular momentum, and rotational energy of a mobile terminal over time when the holder of the mobile terminal falls over. 11A and 11B are diagrams showing experimental results of the acceleration, angular velocity, and angular acceleration of a mobile terminal over time when the mobile terminal is in free fall. 11A and 11B are diagrams showing experimental results of changes in acceleration, angular momentum, and rotational energy of a mobile terminal over time when the mobile terminal is in free fall. 11A and 11B are diagrams showing experimental results of the maximum angular velocity, angular acceleration, angular momentum, and rotational energy of a mobile terminal when the holder of the mobile terminal falls over and when the mobile terminal is in free fall. FIG. 13 illustrates predetermined thresholds for acceleration and rotation parameters of a mobile terminal. 13A to 13C are diagrams illustrating a procedure of another fall determination process according to the present disclosure. 1A and 1B are diagrams illustrating application examples of the fall determination system of the present disclosure. FIG. 1 is a diagram illustrating an example of the configuration of a fall determination system according to the present disclosure. 11 is a diagram showing the procedure of a first fall warning process of the present disclosure. FIG. 11 is a diagram showing the procedure of a second fall warning process of the present disclosure. FIG. 13 is a diagram showing the procedure of a third fall warning process of the present disclosure. A diagram showing the procedure of the fourth fall warning process of the present disclosure. A diagram showing the procedure of the fifth fall warning process of the present disclosure. A diagram showing the procedure of the sixth fall warning process of the present disclosure.

Embodiments of the present disclosure will be described with reference to the accompanying drawings. The embodiments described below are examples of implementation of the present disclosure, and the present disclosure is not limited to the following embodiments.

(Fall Determination Using Threshold Settings)
The configuration of the fall determination system of the present disclosure is shown in Fig. 1. The procedure of the fall determination process of the present disclosure is shown in Fig. 2. The fall determination system F includes a mobile terminal 1 and a server device 2. The mobile terminal 1 includes an acceleration sensor 11, an acceleration acquisition unit 12, a fall determination unit 13, and a wireless communication unit 14, and can be realized by installing the fall determination program shown in Fig. 2 in the mobile terminal 1. The server device 2 includes a wireless communication unit 21 and a fall warning unit 22, and can be realized by installing the fall warning program shown in Fig. 2 in a computer.

In the present disclosure, based on the magnitude of the acceleration of the mobile terminal 1 and the magnitude of the parameters of the rotational motion of the mobile terminal 1, it is determined whether the holder of the mobile terminal 1 has fallen onto the water or onto the ground, or whether the mobile terminal 1 has fallen freely onto the water or onto the ground.

When the holder of mobile device 1 falls onto the water or onto the ground, the acceleration of mobile device 1 is the combined acceleration of gravitational acceleration and centrifugal acceleration, and there is a time when it becomes slightly smaller than 1G, and there is a time when the parameters of the rotational motion of mobile device 1 become larger due to the conversion from potential energy to rotational motion energy, regardless of the fact that there was no rotation before the holder of mobile device 1 fell.

On the other hand, when the mobile device 1 is free falling onto the water surface or the ground, the acceleration of the mobile device 1 is the combined acceleration of the gravitational acceleration and the inertial acceleration, and there is a time when it is 0G. In addition to the lack of rotation before the mobile device 1 is free falling, the parameters of the rotational motion of the mobile device 1 are only converted from potential energy to linear kinetic energy, and there is no time for them to increase due to the conservation of angular momentum.

There is sufficient time remaining from the time when it is determined that the acceleration of the mobile device 1 is small and that the parameters of the rotational motion of the mobile device 1 are large until the time when the holder of the mobile device 1 falls onto the water or onto the ground, or until the mobile device 1 falls freely onto the water or onto the ground. Therefore, the fall determination process and fall warning process shown in FIG. 2 can be executed.

The acceleration acquisition unit 12 acquires information on the acceleration of the mobile terminal 1 and information on parameters of the rotational motion of the mobile terminal 1 from the acceleration sensor 11 of the mobile terminal 1 (step S1). Here, the acceleration acquisition unit 12 acquires at least one of the angular velocity, angular acceleration, angular momentum, time derivative of angular momentum, rotational energy, and time derivative of rotational energy of the mobile terminal 1 as information on parameters of the rotational motion of the mobile terminal 1 (step S1).

The overturning determination unit 13 removes the components of the ship's motion caused by waves on the water surface or the noise components of the acceleration sensor 11 from the information on the acceleration of the mobile terminal 1 and the information on the parameters of the rotational motion of the mobile terminal 1 (step S2). A digital filter including an adaptive filter and a low-pass filter can be used as the overturning determination unit 13. In addition, if the wave height of the ship's motion caused by waves on the water surface is 30 cm and the period is 2 seconds, the maximum value is about 0.3 G when d ² /dt ² (0.3 sin (2 * 3.14 * 0.5t)) is calculated. Furthermore, it is possible to prevent high-frequency noise of the acceleration sensor 11 from being superimposed on the time derivative of the parameters of the rotational motion of the mobile terminal 1, and it is possible to prevent erroneous determination of either the overturn of the holder of the mobile terminal 1 or the free fall of the mobile terminal 1.

Then, the fall determination unit 13 determines that the holder of the mobile terminal 1 has fallen onto the water or the ground (step S5) based on the fact that the magnitude of the parameter of the rotational motion of the mobile terminal 1 is equal to or greater than a predetermined threshold value (step S4) within a time period during which the magnitude of the acceleration of the mobile terminal 1 is equal to or less than a predetermined threshold value (step S3).

On the other hand, the fall determination unit 13 determines that the mobile device 1 has fallen freely onto the water surface or the ground (step S6) based on the fact that the magnitude of the parameter of the rotational motion of the mobile device 1 is smaller than a predetermined threshold value (step S4) within a time period when the magnitude of the acceleration of the mobile device 1 is equal to or smaller than a predetermined threshold value (step S3).

Then, based on the magnitude of the acceleration of the mobile device 1 being greater than a predetermined threshold value described later (NO in step S3), the fall determination unit 13 determines that there is no abnormality in the holder of the mobile device 1 or the mobile device 1, without even based on whether the magnitude of the parameter of the rotational motion of the mobile device 1 is equal to or greater than a predetermined threshold value described later (step S7).

In the mobile terminal 1, the wireless communication unit 14 notifies the server device 2 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground. In the server device 2, the wireless communication unit 21 is notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground.

After being notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground (YES in step S8), the fall warning unit 22 issues a warning that the holder of the mobile terminal 1 has fallen onto the water or onto the ground (step S10) based on the fact that communication has been interrupted (YES in step S9). Here, when notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground, the fall warning unit 22 may issue a warning that the holder of the mobile terminal 1 has fallen onto the water or onto the ground, regardless of whether communication has been interrupted.

Figure 3 shows the simulation results of the time changes in the tipping angle, angular velocity, and acceleration of mobile terminal 1 when the holder of mobile terminal 1 tips over. Figure 4 shows the simulation results of the time changes in the acceleration, angular velocity, and angular acceleration of mobile terminal 1 when the holder of mobile terminal 1 tips over. Figure 5 shows the simulation results of the time changes in the acceleration, angular momentum, and rotational energy of mobile terminal 1 when the holder of mobile terminal 1 tips over. Figures 3 to 5 deal with a situation in which holder P of mobile terminal 1 tips over from ship S onto the water surface W. Here, holder P of mobile terminal 1 is treated as a rigid rod model. The rigid rod model can rotate once without the water surface W.

If the weight of the holder P of the portable terminal 1 is M and the height of the holder P of the portable terminal 1 is L, then the moment of inertia of the holder P of the portable terminal 1 is I _P = 1/3ML ^2. If the tipping angle of the holder P of the portable terminal 1 is θ and the angular velocity of the portable terminal 1 is ω, then the law of conservation of energy for the holder P of the portable terminal 1 is 1/2I _P ω ² = MgL sin ² (θ/2).

The angular velocity of mobile terminal 1 is ω = dθ/dt = √(6g/L) sin(θ/2). If the holding height of mobile terminal 1 is r, then the acceleration of mobile terminal 1 is a = √((g- ^rω2 cos θ) ² + ( ^rω2 sin θ) ² ). If the moment of inertia of mobile terminal 1 is I _M , then the angular momentum of mobile terminal 1 is I _M ω, and the rotational energy of mobile terminal 1 is 1/2I _M ^ω2 .

Then, approximately 2.5 seconds after the start of the tipping over of the holder P of the mobile terminal 1, the tipping angle θ of the holder P of the mobile terminal 1 becomes π/2 rad. Meanwhile, approximately 2.1 to 2.2 seconds after the start of the tipping over of the holder P of the mobile terminal 1, the acceleration a of the mobile terminal 1 becomes 0.7 G or less. In other words, there remains a sufficient time of approximately 0.3 to 0.4 seconds from when the acceleration a of the mobile terminal 1 becomes 0.7 G or less until the tipping angle θ of the holder P of the mobile terminal 1 becomes π/2 rad.

Then, within the time when the acceleration a of the portable terminal 1 becomes 0.7 G or less, (1) the angular velocity ω of the portable terminal 1 has a maximum value of a finite value of approximately 2 rad/s, (2) the angular acceleration dω/dt of the portable terminal 1 has a maximum value of a finite value of approximately 6 rad/ ^s2 , (3) the angular momentum I _M ω of the portable terminal 1 has a maximum value of a finite value of approximately 0.002 Nms, (4) the time derivative of the angular momentum d(I _M ω)/dt of the portable terminal 1 has a maximum value of a finite value of approximately 0.006 Nm, (5) the rotational energy 1/2I _M ^ω2 of the portable terminal 1 has a maximum value of a finite value of approximately 0.003 J, and (6) the time derivative of the rotational energy of the portable terminal 1 d(1/2I _M ^ω2 )/dt has a maximum value of a finite value of approximately 0.015 W.

The fall determination unit 13 may determine that the holder of the mobile terminal 1 has fallen onto the water or onto the ground when a negative correlation is observed between the change over time in the potential energy of the mobile terminal 1 and the change over time in the rotational energy of the mobile terminal 1. The fall determination unit 13 may also determine that the mobile terminal 1 has fallen freely onto the water or onto the ground when no correlation is observed between the change over time in the potential energy of the mobile terminal 1 and the change over time in the rotational energy of the mobile terminal 1. Here, the fall determination unit 13 can calculate the potential energy of the mobile terminal 1 based on the acceleration of the mobile terminal 1, and ultimately based on the fall distance of the mobile terminal 1.

Figure 6 shows the experimental results of the time changes in acceleration, angular velocity, and angular acceleration of mobile terminal 1 when the holder of mobile terminal 1 falls. Figure 7 shows the experimental results of the time changes in acceleration, angular momentum, and rotational energy of mobile terminal 1 when the holder of mobile terminal 1 falls. Figures 6 and 7 deal with a situation in which the holder of mobile terminal 1 falls not onto the surface of water or the ground, but onto an environment that simulates the surface of water or the ground (e.g., a protective mat, etc.).

Then, when time t is between about 101.57 and 101.86 seconds, the acceleration a of mobile terminal 1 is 0.7 G or less. On the other hand, when time t is about 101.86 seconds, the holder of mobile terminal 1 falls into the environment simulating the surface of water or the ground, and as a result, the acceleration a of mobile terminal 1 increases rapidly to about 4 G. In other words, there is a sufficient time of about 0.3 seconds remaining from when the acceleration a of mobile terminal 1 falls to 0.7 G or less until the holder of mobile terminal 1 falls into the environment simulating the surface of water or the ground.

Then, within the time when the acceleration a of the mobile terminal 1 becomes 0.7 G or less, (1) the angular velocity ω of the mobile terminal 1 has a maximum value of a finite value of approximately 5 rad/s, (2) the angular acceleration dω/dt of the mobile terminal 1 has a maximum value of a finite value of approximately 150 rad/ ^s2 , (3) the angular momentum I _M ω of the mobile terminal 1 has a maximum value of a finite value of approximately 0.002 Nms, (4) the time derivative of the angular momentum d(I _M ω)/dt of the mobile terminal 1 has a maximum value of a finite value of approximately 0.02 Nm, (5) the rotational energy 1/2I _M ^ω2 of the mobile terminal 1 has a maximum value of a finite value of approximately 0.01 J, and (6) the time derivative of the rotational energy of the mobile terminal 1 d(1/2I _M ^ω2 )/dt has a maximum value of a finite value of approximately 0.1 W.

Figure 8 shows the experimental results of the time changes in acceleration, angular velocity, and angular acceleration of the mobile terminal 1 when it is in free fall. Figure 9 shows the experimental results of the time changes in acceleration, angular momentum, and rotational energy of the mobile terminal 1 when it is in free fall. Figures 8 and 9 deal with a situation in which the mobile terminal 1 is free falling not on the surface of water or the ground, but on an environment that simulates the surface of water or the ground (e.g., a protective mat, etc.).

Then, when time t is between about 4017.54 and 4017.96 seconds, the acceleration a of the mobile terminal 1 is 0.7 G or less. When time t is between about 4017.56 and 4017.96 seconds, the acceleration a of the mobile terminal 1 is 0 G. On the other hand, when time t is about 4017.96 seconds, the mobile terminal 1 reaches an environment simulating the water surface or ground, and as a result, the acceleration a of the mobile terminal 1 increases rapidly to about 6 G. In other words, there is a sufficient time of about 0.4 seconds remaining after the acceleration a of the mobile terminal 1 falls to 0.7 G or less until the mobile terminal 1 reaches an environment simulating the water surface or ground.

Then, within the time when the acceleration a of the mobile terminal 1 becomes 0.7 G or less, (1) the angular velocity ω of the mobile terminal 1 has a maximum value of a finite value of approximately 2 rad/s, (2) the angular acceleration dω/dt of the mobile terminal 1 has a maximum value of a finite value of approximately 60 rad/ ^s2 , (3) the angular momentum I _M ω of the mobile terminal 1 has a maximum value of a finite value of approximately 0.001 Nms, (4) the time derivative of the angular momentum d(I _M ω)/dt of the mobile terminal 1 has a maximum value of a finite value of approximately 0.01 Nm, (5) the rotational energy 1/2I _M ^ω2 of the mobile terminal 1 has a maximum value of a finite value of approximately 0.001 J, and (6) the time derivative of the rotational energy of the mobile terminal 1 d(1/2I _M ^ω2 )/dt has a maximum value of a finite value of approximately 0.01 W.

Figure 10 shows the experimental results of the maximum angular velocity, angular acceleration, angular momentum, and rotational energy of mobile terminal 1 when the holder of mobile terminal 1 falls and when mobile terminal 1 falls freely. Figure 10 deals with a situation in which the holder of mobile terminal 1 falls onto an environment that simulates a water surface or ground (e.g., a protective mat, etc.) rather than the water surface or ground, and deals with a situation in which mobile terminal 1 falls freely onto an environment that simulates a water surface or ground (e.g., a protective mat, etc.) rather than the water surface or ground.

During the first free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 becomes 0.7 G or less, the following values are obtained: maximum value of angular velocity ω of the mobile terminal 1 = 2.1 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 48.45 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.001703 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.007162 W.

During the second free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 became 0.7 G or less, the following values were obtained: maximum value of angular velocity ω of the mobile terminal 1 = 1.7 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 33.61 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.005556 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.007296 W.

During the third free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 became 0.7 G or less, the following values were obtained: maximum value of angular velocity ω of the mobile terminal 1 = 0.7634 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 18 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.001222 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.000551 W.

During the fourth free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 became 0.7 G or less, the following values were obtained: maximum value of angular velocity ω of the mobile terminal 1 = 3.4 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 25 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.001932 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.029164 W.

During the fifth free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 became 0.7 G or less, the following values were obtained: maximum value of angular velocity ω of the mobile terminal 1 = 6.7 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 48.28 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.045601 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.055571 W.

During the sixth free fall of the mobile terminal 1, within the time when the acceleration a of the mobile terminal 1 became 0.7 G or less, the following values were obtained: maximum value of angular velocity ω of the mobile terminal 1 = 6.43 rad/s, maximum value of angular acceleration dω/dt of the mobile terminal 1 = 76 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 = 0.030838 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 = 0.042937 W.

When the holder of mobile device 1 falls for the first time, the maximum values of the angular velocity ω of mobile device 1 within the time period in which the acceleration a of mobile device 1 becomes 0.7 G or less are as follows: maximum value of angular velocity ω of mobile device 1 = 4.8869 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 136.13 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of angular momentum of mobile device 1 = 0.01563 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of rotational energy of mobile device 1 = 0.08315 W.

When the holder of mobile device 1 falls for the second time, the maximum values of the angular velocity ω of mobile device 1 within the time period in which the acceleration a of mobile device 1 becomes 0.7 G or less are as follows: maximum value of angular velocity ω of mobile device 1 = 1.3123 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 62.0377 rad/ ^s2 , maximum value of time derivative of angular momentum d(I _M ω)/dt of mobile device 1 = 0.066087 Nm, maximum value of time derivative of rotational energy d(1/2I _M ^ω2 )/dt of mobile device 1 = 0.52725 W.

When the holder of mobile device 1 falls for the third time, the maximum values of the angular velocity ω of mobile device 1 within the time period in which the acceleration a of mobile device 1 becomes 0.7 G or less are as follows: maximum value of angular velocity ω of mobile device 1 = 2.8816 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 105.5527 rad/ ^s2 , maximum value of time derivative of angular momentum d(I _M ω)/dt of mobile device 1 = 0.17117 Nm, maximum value of time derivative of rotational energy d(1/2I _M ^ω2 )/dt of mobile device 1 = 0.018771 W.

When the holder of mobile device 1 falls for the fourth time, the maximum values of the angular velocity ω of mobile device 1 within the time period in which the acceleration a of mobile device 1 becomes 0.7 G or less are as follows: maximum value of angular velocity ω of mobile device 1 = 5.574 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 64.4028 rad/ ^s2 , maximum value of time derivative d(I _M ω)/dt of angular momentum of mobile device 1 = 0.05557 Nm, maximum value of time derivative d(1/2I _M ^ω2 )/dt of rotational energy of mobile device 1 = 0.16694 W.

When the holder of mobile device 1 falls for the fifth time, the acceleration a of mobile device 1 becomes 0.7 G or less within the time period in which it does so: maximum value of angular velocity ω of mobile device 1 = 9.1059 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 77.8076 rad/ ^s2 , maximum value of time derivative of angular momentum d(I _M ω)/dt of mobile device 1 = 0.077995 Nm, maximum value of time derivative of rotational energy d(1/2I _M ^ω2 )/dt of mobile device 1 = 0.087218 W.

When the holder of mobile device 1 falls for the sixth time, the acceleration a of mobile device 1 becomes 0.7 G or less within the time period in which it does so, the following values are obtained: maximum value of angular velocity ω of mobile device 1 = 7.1599 rad/s, maximum value of angular acceleration dω/dt of mobile device 1 = 69.2901 rad/ ^s2 , maximum value of time derivative of angular momentum d(I _M ω)/dt of mobile device 1 = 0.31457 Nm, maximum value of time derivative of rotational energy d(1/2I _M ^ω2 )/dt of mobile device 1 = 0.12749 W.

Generally, the predetermined threshold value for the acceleration a of the mobile device 1 in step S3 can be set to (1) a value greater than the simulation result and the experimental result of the minimum value of the acceleration a of the mobile device 1 when the holder of the mobile device 1 falls, (2) a value slightly smaller than the gravitational acceleration of 1 G, or (3) for example, as shown in FIG. 11.

On the other hand, the predetermined threshold value for the parameters of the rotational motion of the mobile device 1 in step S4 may be set (1) to a value smaller than the simulation results and experimental results of the maximum values of the parameters of the rotational motion of the mobile device 1 when the holder of the mobile device 1 falls and when the acceleration a of the mobile device 1 is less than or equal to the predetermined threshold value, (2) to a value larger than the simulation results and experimental results of the maximum values of the parameters of the rotational motion of the mobile device 1 when the mobile device 1 is in free fall and when the acceleration a of the mobile device 1 is less than or equal to the predetermined threshold value, or (3) to a value as shown in FIG. 11, for example.

The predetermined thresholds for the acceleration and rotation parameters of the mobile terminal 1 are shown in FIG. 11. The predetermined thresholds for the acceleration and rotation parameters of the mobile terminal 1 shown in FIG. 11 can vary depending on the height L of the person holding the mobile terminal 1, the height at which the mobile terminal 1 is held, the radius of rotation, and the moment of inertia.

In the first to third determination methods, the predetermined threshold value for step S3 for the acceleration a of the mobile terminal 1 is set to a value between 0.7 G and 0.9 G. Furthermore, the condition for step S3 to be satisfied for the acceleration a of the mobile terminal 1 is set to a value that the state in question must continue for approximately 0.1 seconds, taking into account the measurement error of the acceleration a of the mobile terminal 1. However, the condition for step S3 to be satisfied for the acceleration a of the mobile terminal 1 may be set to be that the state in question must be satisfied even for just an instant.

In the first determination method, the angular velocity ω and angular acceleration dω/dt of the mobile terminal 1 are used as the determination materials, and the predetermined threshold in step S4 for the angular velocity ω of the mobile terminal 1 is set to a value between 3 rad/s and 6 rad/s, and the predetermined threshold in step S4 for the angular acceleration dω/dt of the mobile terminal 1 is set to a value between 9 rad/ ^s2 and 60 rad/ ^s2 . In the second determination method, the predetermined threshold in step S4 for the time derivative d(I _M ω)/dt of the angular momentum of the mobile terminal 1 is set to a value between 0.008 Nm and 0.06 Nm. In the third determination method, the predetermined threshold in step S4 for the time derivative d(1/2I _M ^ω2 )/dt of the rotational energy of the mobile terminal 1 is set to a value between 0.01 W and 0.05 W.

(Fall detection using machine learning)
The procedure of another fall determination process of the present disclosure is shown in Fig. 12. The fall determination unit 13 receives as input data the magnitude of the acceleration of the mobile terminal 1 and the magnitude of the parameter of the rotational motion of the mobile terminal 1, and receives as training data bit values indicating that the holder of the mobile terminal 1 has fallen onto the water or the ground and that the mobile terminal 1 has freely fallen onto the water or the ground, and performs learning using the input data and the training data (step S11).

Here, a neural network, a genetic algorithm, deep learning, or the like can be used as the fall determination unit 13. For example, in the input layer of the neural network, experimental results of the magnitude of the acceleration of the mobile terminal 1 on the sea or in an environment simulating the sea (for example, a protective mat, etc.) and experimental results of the magnitude of the parameter of the rotational motion of the mobile terminal 1 on the sea or in an environment simulating the sea (for example, a protective mat, etc.) are input. Then, in the output layer of the neural network, bit values are output that the holder of the mobile terminal 1 has fallen on the sea surface or in an environment simulating the sea surface, that the mobile terminal 1 has fallen freely on the sea surface or in an environment simulating the sea surface, and that the holder of the mobile terminal 1 has not fallen and the mobile terminal 1 has not fallen freely. In this way, machine learning using teacher data is executed.

Specifically, consider handling the acceleration of the mobile terminal 1 as a physical quantity. 50 experiments are performed for each of the falling of the holder of the mobile terminal 1 and the free fall of the mobile terminal 1, and the time series of the acceleration of the mobile terminal 1 for 1 second that falls below the predetermined threshold of 0.7 G is extracted. If the sampling time is 5 msec, 200 sampling data can be obtained per second. The input layer, intermediate layer, and output layer of the corresponding neural network are composed of 200 neurons, 10 neurons, and 1 neuron, respectively. As a teacher signal, a teacher signal is assigned such that 1 indicates the falling of the holder of the mobile terminal 1, and 0 indicates the free fall of the mobile terminal 1. Learning is completed when the error between the neural network and the teacher signal approaches 0. When it is actually desired to make a judgment, when the acceleration of the mobile terminal 1 that falls below the predetermined threshold of 0.7 G is detected, the time series data of the acceleration of the mobile terminal 1 for 1 second that falls below the predetermined threshold of 0.7 G can be input to the trained neural network to judge the falling of the holder of the mobile terminal 1 and the free fall of the mobile terminal 1. When the acceleration of the mobile device 1 does not fall below the predetermined threshold of 0.7 G, normal operation occurs.

The acceleration acquisition unit 12 acquires information on the acceleration of the mobile terminal 1 and information on parameters of the rotational motion of the mobile terminal 1 from the acceleration sensor 11 of the mobile terminal 1 (step S12). Here, the acceleration acquisition unit 12 acquires at least one of the angular velocity, angular acceleration, angular momentum, time derivative of angular momentum, rotational energy, and time derivative of rotational energy of the mobile terminal 1 as information on parameters of the rotational motion of the mobile terminal 1 (step S12).

The overturning determination unit 13 removes the components of the ship's motion caused by waves on the water surface or the noise components of the acceleration sensor 11 from the information on the acceleration of the mobile terminal 1 and the information on the parameters of the rotational motion of the mobile terminal 1 (step S13). A digital filter including an adaptive filter and a low-pass filter can be used as the overturning determination unit 13. In addition, if the wave height of the ship's motion caused by waves on the water surface is 30 cm and the period is 2 seconds, the maximum value is about 0.3 G when d ² /dt ² (0.3 sin (2 * 3.14 * 0.5t)) is calculated. Furthermore, it is possible to prevent high-frequency noise of the acceleration sensor 11 from being superimposed on the time derivative of the parameters of the rotational motion of the mobile terminal 1, and it is possible to prevent erroneous determination of either the overturn of the holder of the mobile terminal 1 or the free fall of the mobile terminal 1.

Then, in step S11, the fall determination unit 13 inputs the acceleration information of the mobile terminal 1 and the parameter information of the rotational motion of the mobile terminal 1 to the input layer in the neural network or the like, and outputs one of the following (1) to (3) as a bit value from the output layer: (1) determines that the holder of the mobile terminal 1 has fallen onto the water or the ground (step S14), (2) determines that the mobile terminal 1 has fallen freely onto the water or the ground (step S15), or (3) determines that there is nothing abnormal with the holder of the mobile terminal 1 or the mobile terminal 1 (step S16).

In the mobile terminal 1, the wireless communication unit 14 notifies the server device 2 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground. In the server device 2, the wireless communication unit 21 is notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground.

After being notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground (YES in step S17), the fall warning unit 22 issues a warning that the holder of the mobile terminal 1 has fallen onto the water or onto the ground (step S19) based on the fact that communication has been interrupted (YES in step S18). Here, when notified by the mobile terminal 1 that the holder of the mobile terminal 1 has fallen onto the water or onto the ground, the fall warning unit 22 may issue a warning that the holder of the mobile terminal 1 has fallen onto the water or onto the ground, regardless of whether communication has been interrupted.

(Effects of the Invention of the Present Disclosure)
The effects of the invention of the present disclosure are summarized below. As shown in Figures 1 to 12, by using the acceleration sensor 11 of the mobile terminal 1, it is possible to determine and communicate with high accuracy whether the holder of the mobile terminal 1 has fallen onto the water or the ground, or whether the mobile terminal 1 has fallen freely onto the water or the ground, within the time (about 1 second) that the holder of the mobile terminal 1 falls onto the water or the ground, or within the time (about 0.5 seconds) that the mobile terminal 1 falls freely onto the water or the ground.

As shown in Figures 1 to 11, it is possible to determine that the holder of the mobile terminal 1 has fallen onto the water or onto the ground based on the fact that the acceleration of the mobile terminal 1 is small and the parameters of the rotational motion of the mobile terminal 1 are large. Then, as shown in steps S3 and S4 of Figure 2, the acceleration of the mobile terminal 1, which is less susceptible to the influence of the shaking of the mobile terminal 1, is determined before the parameters of the rotational motion of the mobile terminal 1, which are more susceptible to the influence of the shaking of the mobile terminal 1, is determined, so that it is possible to avoid erroneously determining that the holder of the mobile terminal 1 has fallen onto the water or onto the ground.

As shown in Figures 1 to 11, it is possible to determine that the mobile terminal 1 has freely fallen to the water surface or the ground based on the fact that the acceleration of the mobile terminal 1 is small and the parameters of the rotational motion of the mobile terminal 1 are small. Then, as shown in steps S3 and S4 of Figure 2, the acceleration of the mobile terminal 1, which is less susceptible to the shaking of the mobile terminal 1, is determined before the parameters of the rotational motion of the mobile terminal 1, which are susceptible to the shaking of the mobile terminal 1, are determined, so that it is possible to avoid erroneously determining that the mobile terminal 1 has freely fallen to the water surface or the ground.

As shown in Figures 1 to 11, without an engineer having to set a predetermined threshold value for the parameters of the acceleration and rotational motion of the mobile device 1, as shown in Figure 12, it is possible to determine with high accuracy whether the holder of the mobile device 1 has fallen onto the water or the ground, or whether the mobile device 1 has fallen freely onto the water or the ground, simply by mechanically learning using training data for the parameters of the acceleration and rotational motion of the mobile device 1.

As shown in FIG. 11, by using any one or a combination of the angular velocity, angular acceleration, angular momentum, time derivative of angular momentum, rotational energy, and time derivative of rotational energy of the mobile device 1, it is possible to determine with high accuracy whether the holder of the mobile device 1 has fallen onto the water or the ground, or whether the mobile device 1 has fallen freely onto the water or the ground.

As shown in steps S2 and S13 of Figures 2 and 12, only the components of the ship's motion or the noise components of the acceleration sensor 11 are removed from the information on the parameters of the acceleration and rotational motion of the mobile terminal 1, and only the components of the toppling of the holder of the mobile terminal 1 or the components of the free fall of the mobile terminal 1 are extracted, so that it is possible to determine with high accuracy whether the holder of the mobile terminal 1 has toppled over onto the water surface or the mobile terminal 1 has fallen freely onto the water surface.

As shown in steps S8 to S10 and S17 to S19 in Figures 2 and 12, after the owner of the mobile terminal 1 falls onto the water or onto the ground, the server device 2 can issue a highly accurate warning that the owner of the mobile terminal 1 has fallen onto the water or onto the ground, based on the fact that the mobile terminal 1 is unable to communicate underwater or is destroyed on the ground.

When warning that the holder of the mobile terminal 1 has fallen onto the water, the fall warning unit 22 may (1) escalate the warning level in the order of family, fishing port, and administrative authority, (2) determine that the holder of the mobile terminal 1 has fallen based on an image captured by an artificial satellite (if the vessel is heading towards the fishing association, it is determined that the holder of the mobile terminal 1 has not fallen onto the water. If the vessel is stopped on the spot, it is determined that the holder of the mobile terminal 1 has fallen onto the water), (3) determine that the holder of the mobile terminal 1 has fallen based on an image captured by the mobile terminal 1 (if the image captured by the mobile terminal 1 is not tilted, it is determined that the holder of the mobile terminal 1 has not fallen onto the water. If the image captured by the mobile terminal 1 is tilted, it is determined that the holder of the mobile terminal 1 has fallen onto the water), or (4) output information on the time and position of the fall of the holder of the mobile terminal 1.

When the angular velocity resolution of the mobile device 1 is low, the measured angular velocity values of the mobile device 1 may be the same value continuously over time, and the calculated angular acceleration value of the mobile device 1 may be zero continuously over time. Therefore, when deriving the calculated angular acceleration value of the mobile device 1 based on the measured angular velocity values of the mobile device 1, the acceleration acquisition unit 12 may replace the calculated angular acceleration values of the mobile device 1 that are zero continuously over time with the most recent non-zero value of the calculated angular velocity value of the mobile device 1.

The LTE base station as server device 2 increases the transmission output when the reception sensitivity drops, so communication between the LTE base station as server device 2 and mobile terminal 1 is not immediately cut off even when the holder of mobile terminal 1 falls into the water. However, it is desirable for the fall determination unit 13 to quickly determine that the holder of mobile terminal 1 has fallen into the water, and for the wireless communication unit 14 to quickly notify that the holder of mobile terminal 1 has fallen into the water.

(Fall warning and position display)
An application example of the toppling determination system of the present disclosure is shown in Fig. 13. A holder P-1 of a mobile terminal 1-1 is a lookout for the ship S, and a holder P-2 of a mobile terminal 1-2 is the operator of the ship S. Even if the holder P-1 of the mobile terminal 1-1 falls from the stern of the ship S onto the water, it is possible that the holder P-2 of the mobile terminal 1-2 will not notice in the pilothouse of the ship S.

A configuration example of the fall determination system of the present disclosure is shown in FIG. 14. The steps of the first to sixth fall warning processes of the present disclosure are shown in FIG. 15 to FIG. 20. The fall determination system F includes mobile terminals 1-1 and 1-2, a server device 2, and a navigation device 3. The mobile terminal 1-1 includes an acceleration sensor 11, an acceleration acquisition unit 12, a fall determination unit 13, a wireless communication unit 14, a communication linkage unit 15, and a position acquisition unit 16, and can be realized by installing the fall notification program shown in FIG. 15 to FIG. 20. The mobile terminal 1-2, the server device 2, and the navigation device 3 include a wireless communication unit 21, a fall warning unit 22, a communication linkage unit 23, and a position display unit 24, and can be realized by installing the fall warning program shown in FIG. 15 to FIG. 20. Note that the mobile terminals 1-1 and 1-2 are the same type of mobile terminal. In other words, the mobile terminal 1-1 may further include a fall warning unit 22 and a position display unit 24. The mobile terminal 1-2 may further include an acceleration sensor 11, an acceleration acquisition unit 12, a fall determination unit 13, and a position acquisition unit 16. Below, only the components essential for the explanation of this disclosure will be explained.

The following description will be about wireless communication between the mobile terminal 1-1 and the mobile terminal 1-2. The same is true for wireless communication between the mobile terminal 1-1 and the server device 2 or the navigation device 3. Wireless communication may also be performed from the mobile terminal 1-1 to the mobile terminal 1-2 or the navigation device 3 via the server device 2. However, for wireless communication between the mobile terminal 1-1 and the server device 2, the link between the mobile terminal 1-1 and the server device 2 is not set in advance based on the distance between the mobile terminal 1-1 and the server device 2 (described later in steps S20, S21, etc. of FIG. 15). And for wireless communication between the mobile terminal 1-1 and the server device 2, the holder P-1 of the mobile terminal 1-1 is not warned that he has fallen into the water based on the distance between the mobile terminal 1-1 and the server device 2 (described later in step S29, etc. of FIG. 15).

First, the commonalities between the first to sixth fall warning processes shown in Fig. 15 to Fig. 20 will be described. However, the sixth fall warning process shown in Fig. 20 has only steps S20, S21, and S22 in common with the first to fifth fall warning processes shown in Fig. 15 to Fig. 19. The communication linking unit 15 of the mobile terminal 1-1 and the communication linking unit 23 of the mobile terminal 1-2 cooperate to share fall information and fall position (steps S20, S21).

Specifically, the communication link unit 15 (23) of the mobile terminal 1-1 (1-2) shares and links the tipping information and tipping position with the communication link unit 23 (15) of the mobile terminal 1-2 (1-1) whose distance to the mobile terminal 1-1 (1-2) is closer than a predetermined distance. Here, the distance between the terminals can be calculated based on position information or ship track information from a GPS or the like. And, the predetermined distance can be a distance approximately the size of the ship S.

In the other method, the communication linking unit 15 (23) of the mobile terminal 1-1 (1-2) shares and links the tipping information and tipping position with the communication linking unit 23 (15) of the mobile terminal 1-2 (1-1) that has been set up in advance to link with the mobile terminal 1-1 (1-2). Here, the inter-terminal linking can be set by the crew of the ship S reading two-dimensional codes or the like between each other. However, it is preferable that the crew of the ship S read two-dimensional codes or the like between each other for each voyage of the ship S.

The fall determination unit 13 of the mobile terminal 1-1 determines that the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S22), similar to step S5 of FIG. 2 or step S14 of FIG. 12. The position acquisition unit 16 of the mobile terminal 1-1 acquires the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water. The wireless communication unit 14 of the mobile terminal 1-1 notifies the mobile terminal 1-2 that the holder P-1 of the mobile terminal 1-1 has fallen into the water and the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S23). The wireless communication unit 21 of the mobile terminal 1-2 is notified by the mobile terminal 1-1 that the holder P-1 of the mobile terminal 1-1 has fallen into the water and the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S24).

In this way, it is possible to notify nearby or related parties (P-2, the holder of mobile terminal 1-2) between the holder P-1 of mobile terminal 1-1 and the holder P-1 of the fact that the holder P-1 of mobile terminal 1-1 has fallen into the water and the location where the holder P-1 of mobile terminal 1-1 has fallen into the water at an early stage. Note that information can also be shared about falls on the ground, just as it can about falls on the water.

Here, after the mobile terminal 1-1 notifies the user P-1 of the mobile terminal 1-1 that it has fallen on the water surface, the communication with the mobile terminal 1-2 may be interrupted because communication is not possible under the water surface (step S25). However, after the mobile terminal 1-1 notifies the user P-1 of the mobile terminal 1-1 that it has fallen on the water surface, the communication with the mobile terminal 1-2 may not be interrupted for a while depending on the communication performance of the wireless LAN or 4G, etc. And while the mobile terminal 1-1 continues to notify the user P-1 of the mobile terminal 1-1 that it has fallen on the water surface, the mobile terminal 1-1 may be swept away on the water surface, and the distance between the mobile terminal 1-1 and the mobile terminal 1-2 may become large (step S25).

As described below, the first to fifth fall warning processes shown in Figures 15 to 19 can warn with high accuracy that the holder P-1 of the mobile terminal 1-1 has fallen into the water based on the fact that communication between the mobile terminals 1-1 and 1-2 has been interrupted or the distance between the mobile terminals 1-1 and 1-2 has increased.

Next, the second half of the first fall warning process shown in FIG. 15 will be described. In FIG. 15, it is determined independently whether communication between mobile terminal 1-1 and mobile terminal 1-2 has been interrupted and whether the distance between mobile terminal 1-1 and mobile terminal 1-2 has increased.

First, the fall warning unit 22 of the mobile terminal 1-2 is notified by the mobile terminal 1-1 that the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S24), and then warns the holder P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S27) based on the fact that communication between the mobile terminals 1-2 and 1-1 has been cut off (step S26, YES). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S27).

On the other hand, after being notified by mobile terminal 1-1 that the holder P-1 of mobile terminal 1-1 has fallen into the water (step S24), the fall warning unit 22 of mobile terminal 1-2 does not warn that the holder P-1 of mobile terminal 1-1 has fallen into the water by voice synthesis or the like (step S28) based on the fact that communication between mobile terminal 1-2 and mobile terminal 1-1 is not interrupted (step S26, NO). And the position display unit 24 of mobile terminal 1-2 does not display the position where the holder P-1 of mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S28).

In this way, after the holder P-1 of the mobile terminal 1-1 falls onto the water surface, based on the fact that the mobile terminal 1-1 cannot communicate below the water surface, it is possible to warn people in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) that the holder P-1 of the mobile terminal 1-1 has fallen onto the water surface with high accuracy. Note that, like a fall onto the water surface, a warning can also be output and the position can be displayed for a fall onto the ground.

Alternatively, when the fall warning unit 22 of the mobile terminal 1-2 is notified by the mobile terminal 1-1 of the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S24), it warns the holder P-1 of the mobile terminal 1-1 by voice synthesis or the like (step S30) based on the fact that the distance between the mobile terminals 1-2 and 1-1 has become greater than a predetermined distance (step S29, YES). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S30).

On the other hand, when the fall warning unit 22 of the mobile terminal 1-2 is notified by the mobile terminal 1-1 of the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S24), it does not warn the holder P-1 of the mobile terminal 1-1 has fallen into the water by voice synthesis or the like (step S31) based on the fact that the distance between the mobile terminals 1-2 and 1-1 is still closer than a predetermined distance (step S29, NO). And the position display unit 24 of the mobile terminal 1-2 does not display the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S31).

In this way, after the holder P-1 of the mobile terminal 1-1 falls onto the water surface, based on the fact that the mobile terminal 1-1 has been carried away on the water surface, a highly accurate warning can be issued to people in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) that the holder P-1 of the mobile terminal 1-1 has fallen onto the water surface. Note that, like a fall onto the water surface, a warning can also be output and the position can be displayed for a fall onto the ground.

Next, the latter half of the second fall warning process shown in FIG. 16 will be described. In FIG. 16, determining whether communication between mobile terminal 1-1 and mobile terminal 1-2 has been interrupted takes priority over determining whether the distance between mobile terminal 1-1 and mobile terminal 1-2 has increased. Step S32, YES → Step S34 in FIG. 16 is the same as step S26, YES → Step S27 in FIG. 15. The differences between FIG. 16 and FIG. 15 will be described.

First, the fall warning unit 22 of the mobile terminal 1-2 warns the user P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S34) based on the fact that the distance between the mobile terminal 1-2 and the mobile terminal 1-1 has become greater than a predetermined distance (step S33, YES) even though communication between the mobile terminals 1-2 and 1-1 is not interrupted (step S32, NO). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the user P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S34).

On the other hand, the fall warning unit 22 of the mobile terminal 1-2 does not warn by voice synthesis or the like that the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S35) based on the fact that communication between the mobile terminals 1-2 and 1-1 has not been interrupted (step S32, NO) and that the distance between the mobile terminals 1-2 and 1-1 is still shorter than a predetermined distance (step S33, NO). And the position display unit 24 of the mobile terminal 1-2 does not display the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S35).

Thus, after the holder P-1 of the mobile terminal 1-1 falls onto the water's surface, the mobile terminal 1-1 can communicate below the water's surface, but based on the fact that the mobile terminal 1-1 has been swept away above the water's surface, a warning that the holder P-1 of the mobile terminal 1-1 has fallen onto the water's surface can be issued to people in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) with higher accuracy than in the case of FIG. 15. Note that, like a fall on the water's surface, a warning can also be output and the position can be displayed for a fall on the ground.

Next, the latter half of the third fall warning process shown in FIG. 17 will be described. In FIG. 17, the order of whether communication between mobile terminal 1-1 and mobile terminal 1-2 has been interrupted and then whether the distance between mobile terminal 1-1 and mobile terminal 1-2 has increased is judged equally. Step S36, NO → steps S40 to S42 in FIG. 17 are the same as step S32, NO → steps S33 to S35 in FIG. 16. The differences between FIG. 17 and FIG. 16 will be described.

First, the fall warning unit 22 of the mobile terminal 1-2 warns the user P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S38) based on the fact that communication between the mobile terminals 1-2 and 1-1 has been lost (step S36, YES) and that the distance between the mobile terminals 1-2 and 1-1 has become greater than a predetermined distance (step S37, YES). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the user P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S38).

On the other hand, although communication between mobile terminal 1-2 and mobile terminal 1-1 has been interrupted (step S36, YES), the fall warning unit 22 of mobile terminal 1-2 does not warn by voice synthesis or the like that the holder P-1 of mobile terminal 1-1 has fallen into the water (step S39) based on the fact that the distance between mobile terminal 1-2 and mobile terminal 1-1 is still closer than a predetermined distance (step S37, NO). And the position display unit 24 of mobile terminal 1-2 does not display the position where the holder P-1 of mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S39).

In this way, after the holder P-1 of the mobile terminal 1-1 falls onto the water surface, the mobile terminal 1-1 is unable to communicate underwater, and based on the fact that the mobile terminal 1-1 is swept away above the water surface, a warning that the holder P-1 of the mobile terminal 1-1 has fallen onto the water surface can be issued to people in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) with even greater accuracy than in the case of FIG. 15. Note that, like a fall on the water surface, a warning can also be output and the position can be displayed for a fall on the ground.

Next, the latter half of the fourth fall warning process shown in FIG. 18 will be described. In FIG. 18, determining whether the distance between mobile terminal 1-1 and mobile terminal 1-2 has increased is given priority over determining whether communication between mobile terminal 1-1 and mobile terminal 1-2 has been interrupted. Step S43, YES → step S45 in FIG. 18 is the same as step S29, YES → step S30 in FIG. 15. The differences between FIG. 18 and FIG. 15 will be described.

First, the fall warning unit 22 of the mobile terminal 1-2 warns the user P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S45) based on the fact that communication between the mobile terminals 1-2 and 1-1 has been lost (step S44, YES) even though the distance between the mobile terminals 1-2 and 1-1 is still shorter than a predetermined distance (step S43, NO). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the user P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S45).

On the other hand, the fall warning unit 22 of the mobile terminal 1-2 does not warn by voice synthesis or the like that the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S46) based on the fact that the distance between the mobile terminal 1-2 and the mobile terminal 1-1 is still closer than the predetermined distance (step S43, NO) and communication between the mobile terminal 1-2 and the mobile terminal 1-1 is not interrupted (step S44, NO). And the position display unit 24 of the mobile terminal 1-2 does not display the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S46).

In this way, after the holder P-1 of the mobile terminal 1-1 falls onto the water surface, the mobile terminal 1-1 is not carried away above the water surface, but based on the fact that the mobile terminal 1-1 cannot communicate below the water surface, it is possible to warn those in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) that the holder P-1 of the mobile terminal 1-1 has fallen onto the water surface with even greater accuracy than in the case of FIG. 15. Note that, like a fall on the water surface, a warning can also be output and the position can be displayed for a fall on the ground.

Next, the latter half of the fifth fall warning process shown in Figure 19 will be described. In Figure 19, the order of whether the distance between mobile terminal 1-1 and mobile terminal 1-2 has increased and whether communication between mobile terminal 1-1 and mobile terminal 1-2 has been interrupted is judged equally. Step S47, NO → steps S51 to S53 in Figure 19 are the same as step S43, NO → steps S44 to S46 in Figure 18. The differences between Figure 19 and Figure 18 will be described.

First, the fall warning unit 22 of the mobile terminal 1-2 warns the user P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S49) based on the fact that the distance between the mobile terminal 1-2 and the mobile terminal 1-1 has become greater than a predetermined distance (step S47, YES) and communication between the mobile terminal 1-2 and the mobile terminal 1-1 has been lost (step S48, YES). Then, the position display unit 24 of the mobile terminal 1-2 displays the position where the user P-1 of the mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S49).

On the other hand, although the distance between mobile terminal 1-2 and mobile terminal 1-1 has become greater than the predetermined distance (step S47, YES), the fall warning unit 22 of mobile terminal 1-2 does not warn by voice synthesis or the like that the holder P-1 of mobile terminal 1-1 has fallen into the water (step S50) based on the fact that communication between mobile terminal 1-2 and mobile terminal 1-1 has not been interrupted (step S48, NO). And the position display unit 24 of mobile terminal 1-2 does not display the position where the holder P-1 of mobile terminal 1-1 has fallen into the water by operating the screen or the like (step S50).

In this way, after the holder P-1 of the mobile terminal 1-1 falls onto the water surface, the mobile terminal 1-1 is swept away on the water surface and is unable to communicate below the water surface. Based on this, it is possible to warn those in close proximity to the holder P-1 of the mobile terminal 1-1 or related parties (holder P-2 of mobile terminal 1-2) that the holder P-1 of the mobile terminal 1-1 has fallen onto the water surface with even greater accuracy than in the case of FIG. 15. Note that, like with falls on the water surface, a warning can also be output and the position can be displayed for falls on the ground.

Next, the remaining part of the sixth fall warning process shown in Figure 20 will be described. Figure 20 deals with the case where the holder P-1 of the portable terminal 1-1 falls into the water and is unable to notify the position where the holder P-1 of the portable terminal 1-1 falls into the water.

The communication link unit 15 (23) of the mobile terminal 1-1 (1-2) shares information about the fall, the fall position, the current position, and the communication status with the communication link unit 23 (15) of the mobile terminal 1-2 (1-1) (steps S20, S21). The wireless communication unit 14 (21) of the mobile terminal 1-1 (1-2) periodically or constantly notifies the wireless communication unit 21 (14) of the mobile terminal 1-2 (1-1) of the current position and communication status of the mobile terminal 1-1 (1-2) until the holder P-1 (P-2) of the mobile terminal 1-1 (1-2) falls onto the water surface (steps S54, S55).

The fall determination unit 13 of the mobile terminal 1-1 determines that the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S22). The position acquisition unit 16 of the mobile terminal 1-1 may not be able to detect the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water, because the sooner the holder P-1 of the mobile terminal 1-1 is submerged, the sooner the mobile terminal 1-1 will be unable to communicate. The wireless communication unit 14 of the mobile terminal 1-1 notifies the mobile terminal 1-2 that the holder P-1 of the mobile terminal 1-1 has fallen into the water, but may not be able to notify the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S56). The wireless communication unit 21 of the mobile terminal 1-2 is notified by the mobile terminal 1-1 that the holder P-1 of the mobile terminal 1-1 has fallen into the water, but there may be cases where the wireless communication unit 21 is unable to be notified of the position where the holder P-1 of the mobile terminal 1-1 has fallen into the water (step S57).

The fall warning unit 22 of the mobile terminal 1-2 can determine that communication between the mobile terminal 1-2 and the mobile terminal 1-1 has been interrupted based on the communication state of the mobile terminal 1-1 when the holder P-1 of the mobile terminal 1-1 falls into the water. The fall warning unit 22 of the mobile terminal 1-2 can determine that the distance between the mobile terminal 1-2 and the mobile terminal 1-1 has become greater than a predetermined distance based on the latest position of the mobile terminal 1-1 until the holder P-1 of the mobile terminal 1-1 falls into the water. Then, the fall warning unit 22 of the mobile terminal 1-2 warns the holder P-1 of the mobile terminal 1-1 that he has fallen into the water by voice synthesis or the like (step S58). Then, the position display unit 24 of the mobile terminal 1-2 displays the latest position of the mobile terminal 1-1 until the holder P-1 of the mobile terminal 1-1 falls into the water by screen operation or the like (step S58).

In this way, even if it is not possible to obtain the position where the holder P-1 of the mobile terminal 1-1 falls into the water when the holder P-1 of the mobile terminal 1-1 falls into the water, it is possible to more reliably warn and display the fact that the holder P-1 of the mobile terminal 1-1 has fallen into the water and the latest position of the mobile terminal 1-1 until the holder P-1 of the mobile terminal 1-1 fell into the water to a person in close proximity to or related to the holder P-1 of the mobile terminal 1-1 (holder P-2 of mobile terminal 1-2) compared to the cases of Figures 15 to 19. Note that, as with falls into the water, a warning can also be output and the position can be displayed for falls on the ground.

In this way, the fall determination device, mobile terminal, communication device, and fall determination program disclosed herein use the acceleration sensor of a general-purpose mobile terminal to determine with high accuracy whether the mobile terminal's owner (fisherman, pedestrian, etc.) has fallen onto the water or the ground, or whether the mobile terminal has fallen freely onto the water or the ground, within the time (approximately 1 second) that the mobile terminal's owner falls onto the water or the ground, or within the time (approximately 0.5 seconds) that the mobile terminal falls freely onto the water or the ground, and can communicate quickly and without error.

F: Capsize determination system S: Ship W: Water surface P, P-1, P-2: Owners 1, 1-1, 1-2: Portable terminal 2: Server device 3: Navigation equipment 11: Acceleration sensor 12: Acceleration acquisition unit 13: Capsize determination unit 14: Wireless communication unit 15: Communication linkage unit 16: Position acquisition unit 21: Wireless communication unit 22: Capsize warning unit 23: Communication linkage unit 24: Position display unit

Claims (14)

an acceleration acquisition unit that acquires information on the acceleration of the mobile terminal and information on parameters of the rotational motion of the mobile terminal from an acceleration sensor of the mobile terminal;
a fall determination unit that determines whether the holder of the portable terminal has fallen onto the water or the ground, or whether the portable terminal has fallen freely onto the water or the ground, based on a magnitude of acceleration of the portable terminal and a magnitude of a parameter of rotational motion of the portable terminal at a time before the holder of the portable terminal falls onto the water or the ground, or at a time before the portable terminal falls freely onto the water or the ground;
A fall determination device comprising: The fall determination device according to claim 1, characterized in that the fall determination unit determines that the holder of the mobile device has fallen onto water or the ground based on the magnitude of a parameter of the rotational motion of the mobile device being equal to or greater than a predetermined threshold within a time period in which the magnitude of the acceleration of the mobile device is equal to or less than a predetermined threshold. The fall determination device according to claim 1 or 2, characterized in that the fall determination unit determines that the mobile device has freely fallen to the water surface or the ground based on the magnitude of a parameter of the rotational motion of the mobile device being smaller than a predetermined threshold within a time period in which the magnitude of the acceleration of the mobile device is equal to or smaller than a predetermined threshold. The fall determination unit of claim 1 is characterized in that it receives as input data the magnitude of acceleration of the mobile terminal and the magnitude of a parameter of the rotational motion of the mobile terminal at a time before the holder of the mobile terminal falls onto the water or the ground, or at a time before the mobile terminal falls freely onto the water or the ground, receives as training data bit values indicating that the holder of the mobile terminal has fallen onto the water or the ground, and that the mobile terminal has fallen freely onto the water or the ground, and learns using the input data and the training data. 5. The fall determination device according to claim 1, wherein the acceleration acquisition unit acquires at least one of the following information on the parameters of the rotational motion of the mobile device: angular velocity, angular acceleration, angular momentum, a time derivative of angular momentum, rotational energy, and a time derivative of rotational energy of the mobile device. The overturning determination device according to any one of claims 1 to 5, characterized in that the overturning determination unit removes components of ship motion caused by waves on the water surface or noise components of the acceleration sensor from information on the acceleration of the mobile terminal and information on parameters of the rotational motion of the mobile terminal. A mobile terminal comprising a fall determination device according to any one of claims 1 to 6. The mobile terminal according to claim 7, characterized in that it notifies a communication device that is closer to the mobile terminal than a predetermined distance or that has been previously configured to link with the mobile terminal that the owner of the mobile terminal has fallen onto water or the ground. The mobile terminal according to claim 8, characterized in that the communication device notifies the location where the owner of the mobile terminal has fallen onto the water or ground when the distance between the mobile terminal and the communication device is shorter than the predetermined distance or when the communication device is previously configured to link with the mobile terminal. The mobile terminal according to claim 8, characterized in that the current location of the mobile terminal up until the owner of the mobile terminal falls onto the water or onto the ground is notified to the communication device whose distance to the mobile terminal is shorter than the predetermined distance or whose link with the mobile terminal is preset. A communication device characterized in that after being notified by a mobile terminal according to claim 8, in which the distance between the communication device itself is shorter than the predetermined distance or the link with the communication device itself is preset, that the owner of the mobile terminal has fallen onto the water or the ground, the communication device warns that the owner of the mobile terminal has fallen onto the water or the ground based on the loss of communication between the communication device itself and the mobile terminal. A communication device characterized in that, when a mobile terminal according to claim 9, which is closer to its own communication device than the predetermined distance or which has a preset link with its own communication device, notifies the user of the location where the user of the mobile terminal has fallen onto the water or the ground, the communication device warns the user that the user of the mobile terminal has fallen onto the water or the ground based on the fact that the distance between the communication device and the mobile terminal has become farther than the predetermined distance. A communication device characterized in that, when notified by a mobile terminal according to claim 10 that the distance between the communication device and the communication device is shorter than the predetermined distance or that cooperation with the communication device has been preset, the communication device warns that the mobile terminal's owner has fallen into the water or onto the ground, and displays the latest location of the mobile terminal up until the owner of the mobile terminal fell into the water or onto the ground. A fall determination program for causing a computer to function as a fall determination device according to any one of claims 1 to 6.

Images