Field of the Invention

The invention relates to a system for tracking motion of objects for the purpose of tracking manipulation of movable objects.

State of the Art

Presently, the protection against intrusion into buildings and tampering with items inside the building is solved by security systems which detect motion of an unauthorized person in the secured area through area sensors that work on the infra- red, radio, or microwave principle, or detect the opening of windows/doors through magnetic sensors or the breaking of a window through acoustic/vibration sensors. However, with respect to the used physical principles, these sensors can still be fooled.

Present security systems require installation of a security switchboard to which all the sensors are wired or wirelessly connected. The security switchboard evaluates the information from security sensors and forwards them to the user who can be the owner of the building or a security agency. The security switchboard is the most expensive element of security systems and thus largely determines when the installation of the security system pays off to the user economically. Further restriction of the installation of security systems is the requirement for mains power supply for security switchboard power supply.

A number of solutions is known for transmitting information between sensors and the switchboard, and between the switchboard and the user or the security agency. These solutions usually use the IEEE 802.1 1 standard or M2M mobile networks. However, these solutions are very energy-intensive and thus require electrical network power supply, or, eventually, these batteries have to be often recharged when powered using battery. Another disadvantage of these solutions is the simplicity of jamming thereof and thus disabling the transmission of alarm messages.

In the recent years, new networks are being developed for the area of internet of things, so called Low-Power-Area Network (LPWAN abbreviated, eventually known as LPWA or LPN as well). LPWAN networks use the technology of radio communication LoRa (https://www.lora-alliance.org/), SigFox (http://www.sigfox.com) or NB-loT (Internet of the Things Narrowband). LPWAN networks use a narrow unlicensed band approximately about 868 MHz in Europe, 915 MHz in North America, and 433 MHz in Asia, or, in the case of NB-loT, a licensed band GSSSM and LTE as well (Kais Mekki, Eddy Bajic, Frederic Chaxel, Fernand Meyer, A comparative study of LPWAN technologies for large-scale loT deployment, ICT Express, 2018, ISSN 2405- 9595). The transmission of information through LPWAN networks is energy-efficient due to which it is possible to supply the transmitting modems only from regular batteries in a long term and thus minimalize frequent recharging of these batteries or the need for electrical network power supply. LPWAN networks have, at the same time, wide range which is many times wider than in the case of networks working with the standard IEEE 802.15.4, eventually BLE. The propagation and processing of radio signal in LPWAN networks is also substantially less influenced by building and landscape elements and far more difficult to jam, thanks to which it is possible to transmit data from places where other technologies, such as for example M2M, fail. Solutions using LPWAN networks are thus used especially in open areas or in urban developments as a complex solution that does not require a complicated technological construction.

Prior art has a number of limitations and restrictions. Among the significant ones are dependency on mains power supply, possibility of fooling the sensors, elimination of transmitting alarm messages by jamming the radio channel, higher purchase price determining the effectivity of usage, and the ability to secure only some situations.

Due to the above mentioned disadvantages of security systems known in the art, it would be appropriate to come up with a system which would eliminate said disadvantages and thus would not depend on mains power supply and would not require frequent recharging, the possibility to fool the system would be minimalized and at the same time the number of false messages about recording a motion would be minimal, jamming would not be so easy, and the price would be acceptable for usage in most applications.

Summary of the Invention

The objective mentioned above is achieved by a system for tracking motion of objects containing a remote server and a motion sensor, wherein the motion sensor contains a microcontroller, an accelerometer, and a transmitting unit which is data-connected to the remote server, wherein the microcontroller is data-connected to the accelerometer and the transmitting unit, the motion sensor further contains a power supply electrically connected to the microcontroller, the accelerometer and the transmitting unit, characterized in that the motion sensor further contains a magnetometer electrically connected to the power supply, wherein the magnetometer is at the same time data-connected to the microcontroller, wherein the transmitting unit is further data-connected by the Low-Power Wide-Area Network type of network to the remote server. The system for tracking motion of objects meets the above-mentioned objectives of energy-efficient transmission of information about motion from the motion sensor by using the transmitting unit connected to the remote server by Low -Power Wide-Area Network type of network characterized in low requirements for power supply and wide range. At the same time, it is difficult to jam the system for tracking motion of objects when using the Low-Power Wide-Area Network type of network. The system for tracking motion of objects does not require any cooperation with the security switchboard, thus meeting another objective of price acceptability also in applications where it has been inefficient so far. In a preferred embodiment, the power supply is a battery supply. In alternative embodiments, the power supply is a solar cell.

In a preferred embodiment, the accelerometer is digital, thus allowing processing of measured acceleration directly in the accelerometer.

In a preferred embodiment, the accelerometer contains a high pass filter and an anti-aliasing filter. These filters allow filtration of the measured acceleration, which allows easier evaluation of the measured acceleration because the DC component of gravitational acceleration is filtered by high pass filter and disturbing acceleration caused by the inherent noise of the accelerometer is partially filtered by the anti aliasing filter and thus, after these filtrations are performed, only the acceleration component caused by the inherent motion of the sensor, which is further evaluated by the accelerometer, remains.

A preferred method of tracking motion of objects by which the lower energy- intensity and minimal number of false information indicating motion of the motion sensor is achieved consists of a sequence of steps: - Periodic measurement of acceleration by the accelerometer of frequency 10 to 100 Hz, the microcontroller, the magnetometer, and the transmitting unit being in the sleep mode, waiting for a wake-up signal; - Filtration of acceleration in the accelerometer measured by the accelerometer using the high pass filter and the anti-aliasing filter and evaluation in the accelerometer, whether the filtered signal exceeds the level of acceleration from 0,0005 ms ^-2 to 0,01 ms ² , indicating possible motion of the motion sensor;

- If the accelerometer evaluates that the filtered signal has exceeded the level of acceleration indicating a possible motion of the motion sensor, a wake-up signal is transmitted to the microcontroller;

- After bringing the microcontroller into an active state, receiving information about possible motion of the motion sensor is forbidden in the microcontroller and the magnetometer is brought to an active state by the microcontroller;

- Immediately after the magnetometer is in an active state, the size of the magnetic field in individual axis is measured by the magnetometer and these values are sent to the microcontroller where they are saved as referential values;

- After saving the referential values, the values of sizes of magnetic field in individual axes are measured by the magnetometer for the period TM equal to 5 to 30 s and with the frequency f _m equal to 10 to 100 Hz and these measured values are sent to the microcontroller, where their evaluation by means of difference with the referential values is performed as well as storing the information about exceeding the difference size into the internal memory of the microcontroller of such values, the difference H size of which is higher than 10 to 60 mG in comparison with the referential values;

- After the period T M, the number of exceeding the difference size is evaluated by the microcontroller;

- In case the number of exceeding the difference H size is higher than 1 to 30, the transmitting unit is woken up by the microcontroller and the microcontroller transmits the information about motion of the motion sensor to the remote server through this transmitting unit by Low-Power Wide-Area Network type of network and then puts the transmitting unit to the sleep mode again and, at the same time, the magnetometer is put into the sleep mode by the microcontroller, and, at the same time, receiving information about possible motion of the motion sensor is allowed in the microcontroller and the microcontroller is subsequently put into the sleep mode; - In case the number of exceeding the difference size is lower than 1 to 30, the magnetometer is put into the sleep mode by the microcontroller and, at the same time, receiving information about a possible motion of the motion sensor is allowed in the microcontroller and the microcontroller is subsequently put into the sleep mode.

The objectives of low energy-intensity are achieved also by the fact that the magnetometer, the microcontroller, and the transmitting unit are most of the time in the sleep mode waiting for the wake-up signal and they have minimal energy consumption, at the same time, the accelerometer scans only at the frequency of 10 to 100 Hz thus further lowering the energy-intensity. Another objective, the minimal number of false information indicating the motion of the motion sensor is achieved by using the combination of the accelerometer and the magnetometer, the magnetometer being used to confirm the information about possible motion of the motion sensor evaluated by the accelerometer. The system for tracking motion of objects further contains a user device wirelessly connected to the remote server. Preferably, the information about motion of the motion sensor is sent to the user device by wireless connection from the remote server. The advantage is characterized in the possibility to inform the user about a motion of the motion sensor. In the preferred embodiment, the user device is a phone thanks to the wide-spread usage between users and thus the simplest implementation in comparison to the alternative embodiments. In alternative embodiments, the user device can be a computer, wearable electronics, or specialized device adjusted only for the usage with the system for tracking motion of objects. In a preferred embodiment, the wireless connection of the user device is realized by mobile network thus allowing the connection of the user device with the remote server from any place which is covered by mobile networks. In an alternative embodiment, the wireless connection can be realized using 802.1 1 standard.

The magnetometer and the accelerometer are at least biaxial. In a preferred embodiment, the magnetometer and the accelerometer are rather triaxial, thus allowing the measurement of the acceleration and the size of the magnetic field in all axes. In an alternative embodiment, the magnetometer and the accelerometer are biaxial. Description of the Drawings

The subject matter of the invention is further clarified by means of exemplary embodiments which are described with the reference to the attached drawings, in which: Fig. 1 is a schematic view of the system for tracking motion of objects,

Fig. 2 is an illustrative view of placing the housing of the motion sensor on the window,

Fig. 3 shows the placement of the housing of the motion sensor in the window frame,

Fig. 4 is an illustrative view of the placement of the housing of the motion sensor on the door,

Fig. 5 shows the placement of the housing of the motion sensor in the doorframe.

Exemplary Embodiments of the Technical Solution An example of embodiment of the invention is a system for tracking motion of objects according to Figure 1 containing a remote server 2, a motion sensor 1, and a user device 8. The motion sensor is connected to the remote server 2 by Low-Power Wide-Area Network (LPWAN). The connection of the motion sensor with the remote server 2 is not permanent and it is formed only for sending the information about recorded motion of the motion sensor 1_. The remote server 2 is further wirelessly connected with the user device 8, wherein the connection is realized by the mobile network. The connection of the user device 8 with the remote server 2 is not permanent and is always formed only to send the information about the recorded motion of the motion sensor 1_. The user device 8 is a smart phone. The motion sensor 1 contains a microcontroller 3, an accelerometer 4, a magnetometer 5, a power supply 6 and a transmitting unit 7. The microcontroller 3 contains an internal memory. The accelerometer 4 contains an anti-aliasing filter and a high pass filter. The power supply 6 is a battery supply. The power supply 6 is electrically connected to the microcontroller, 3, the accelerometer 4, the magnetometer 5, and the transmitting unit 7. The electrical connection of the power supply 6 with the accelerometer 4, the magnetometer 5, the microcontroller 3, and the transmitting unit 7 serves for powering the accelerometer 4, the magnetometer 5, the microcontroller 3 and the transmitting unit 7 from the power supply 6. The microcontroller 3 is further data-connected to the transmitting unit 7. The data connection of the transmitting unit 7 with the microcontroller 3 allows transmission of the information about motion of the motion sensor 1 evaluated by the microcontroller 3 to the transmitting unit 7. The transmitting unit 7 uses the LPWAN network for the data connection with the remote server 2. The microcontroller 3 is further data-connected with accelerometer 4 and the magnetometer 5. The information about the data measured by the accelerometer 4 and the data measured by the magnetometer 5 are transmitted to the microcontroller 3 by the data connection thereof. The magnetometer 5 and the accelerometer 4 are triaxial.

In the exemplary method of tracking motion of the objects, the accelerometer 4 is in the low power mode, the accelerometer 4 measuring periodically the acceleration at the frequency of 10 Hz. The acceleration measured by the accelerometer 4 is filtered by the high pass filter and the anti-aliasing filter, the DC component of gravitational acceleration being filtered by the high pass filter and the disturbing acceleration caused by inherent noise of the accelerometer 4 being partially filtered by the anti-aliasing filter. If the signal filtered in this way exceeds the level of acceleration equal, in the preferred embodiment, to 0,001 ms ^-2 , the accelerometer 4 evaluates that it is a possible motion of the motion sensor 1. For the period when there is no possible motion of the motion sensor 1 recorded by the accelerometer 4, the microcontroller 3, the magnetometer 5 and the transmitting unit 7 are in the sleep mode when they do not perform any activity and only wait for the wake-up signal. If the accelerometer 4 evaluates that there is a possible motion of the motion sensor 1, the information to wake up is sent to the microcontroller 3, thus bringing it to the active state. The microcontroller 3 then wakes up the magnetometer 5 from the sleep mode and it is forbidden to receive information about a possible motion of the motion sensor 1 in the microcontroller 3 from the accelerometer 4. After bringing the magnetometer 5 to the active state, the microcontroller 3 starts to receive the measured data therefrom. The microcontroller 3 reads the values of the magnetic field in the individual axes immediately after bringing the magnetometer 5 to the active state and saves them temporarily as referential values. The size of the magnetic field measured by the magnetometer 5 in the individual axes is, after the referential values had been saved for the period TM at the frequency of measurement f _m , sent to the microcontroller which ensures the difference between the actual size of the size of the magnetic field measured by the magnetometer 5 and the saved referential values. The period TM is equal to 20 s. The measurement frequency fm is 10 Hz. If the difference between the actual size of the magnetic field measured by the magnetometer 5 and the referential value exceeds the difference size equal to 30 mG, the microcontroller 3 records this into the internal memory of the microcontroller 3 as a logical value N. The microcontroller 3 can identify the exceeding Ni to N _n of the difference H size for the period TM, where N _n is equal to the product of fm and TM, minus one. After the period TM, the microcontroller 3 evaluates, whether the number of exceeding the difference H size is higher than 9 and respectively decides, whether there is a motion of the motion sensor 1 or whether it is only a disturbing effect which exceeded the preset level of acceleration measured by the accelerometer 4 by its size. If the microcontroller 3 evaluates that there was no motion of the motion sensor 1, it is allowed to receive information about the motion of the motion sensor 1 in the microcontroller 3 from the accelerometer 4 and the magnetometer 5 is put into the sleep mode by the microcontroller 3. Then the microcontroller 3 is put into the sleep mode. If the microcontroller 3 evaluates that there was a motion of the motion sensor 1, the microcontroller 3 wakes the transmitting unit 7 up from the sleep mode and sends the information that there was a motion of the motion sensor 1_through this transmitting unit 7 by the LPWAN network to the remote server 2 and then puts the transmitting unit 7 back to the sleep mode. Then, it is allowed in the microcontroller 3 to receive information about possible motion of the motion sensor 1 from the accelerometer 4 and the magnetometer 5 is put to the sleep mode by the microcontroller 3. The microcontroller 3 is then put into the sleep mode as well. After receiving information about motion of the motion sensor 1 on the remote server 2, the information about motion of the motion sensor 1 is sent from the remote server

2 to the user device 8.

The microcontroller 3, the accelerometer 4, the magnetometer 5, the battery supply 6 and the transmitting unit 7 are arranged in the housing 9 of the motion sensor. The housing 9 of the motion sensor is in the preferred embodiment detachably attached to the movable object. In an alternative embodiment, the housing 9 is inseparably attached to the movable object. In another alternative embodiment, the housing 9 of the motion sensor is integrated into the movable object. The movable object is for example a window 10 or a door 13. In an exemplary embodiment according to the Figs. 2, 3, 4 or 5, where the movable object is, for example, a window 10 or a door 13 containing a frame 1 1 , 14. an attachment of the window 10 or the door 3 to the jambs, and a handle 12, 15 to open the window 10 or the door 13, the housing 9 of the motion sensor can be integrated into the frame 1 1 ,14 of the window 10 or of the door 13. The integration into the frame 1 1 , 14 of the window 10 or the door 13 is in the place spaced apart from the attachment to the jambs and, at the same time, in the place close to the placement of the handle 12, 15. In this placement, the highest acceleration is generated and, at the same time, the biggest changes in the effect of the magnetic field occur due to the significantly different rotation of the window 10 or the door 3 in this place in different opening degrees, and it is thus possible to detect also a very slow opening of the window 10 or of the door 13, when the accelerometer 4 would, in case of setting the sensitivity high, emit a number of false information about the motion, if the magnetometer 5 was not used for verification of the information about a motion of the motion sensor 1. The movable object can also be, for example, a car, a bike, a motorbike, a backpack, a picture, statues, a door, a door of the mailbox, or a window.

Technical Applicability

The system for tracking motion can be used for indication of the motion in an apartment, in the house, in the cottage, or in the cellar, wherein the motion can be, for example, an intrusion, when the indication of the motion is recorded by the motion sensor placed for example on the entrance or inside doors or windows, eventually on the doors of cupboards at the kitchen unit or on a chair, or any other object, which will be probably moved by the intruder, for example, a chair. Further, the system for tracking motion can be used for indication of intrusion into a car, which can be recorded by a motion sensor inserted, for example, in the pocket of the driver’s or passenger’s door. The system for tracking motion can be used also for indication of the access of a stranger to a private content of drawers, backpacks or bags, etc. so that the motion sensor is, for example, inserted or laid upon the desired object with the private content. Further, the system for tracking motion can be used also as a protection against tampering with documentation, a laptop, a drawer with alcohol, etc. so that the motion sensor can be placed on these objects and thus it is necessary to move with it to be able to access the tracked objects. The system for tracking motion can be also used to track the arrivals, for example, of children home from school or to track elderly people living alone, where it is possible, in case of tracking arrivals, to place the motion sensor, for example, on the entrance door and in case of tracking elderly people, it can be placed, for example, on different doors of cupboards or any other objects which can be manipulated from time to time, on regular basis, and in case that does not happen, it is possible to warn the user, that this object has not been manipulated for a certain time.