阅读说明：本技术 用于检测与环境中的可移动物体相关的特性的基于超宽带的系统和方法 (Ultra-wideband based systems and methods for detecting characteristics related to movable objects in an environment ) 是由 李健强 E·J·杰克逊 樊家伦 于 2019-03-28 设计创作，主要内容包括：一种用于检测与诸如室内环境的环境中的可移动物体相关的特性的基于超宽带的系统和方法。该方法包括使用超宽带发送器将超宽带雷达信号发送到环境,以及使用超宽带接收器接收由于所述第一超宽带雷达信号的发送而从所述环境反射的多个信号。该方法还包括使用处理器处理反射的多个信号并基于处理后的反射信号确定与环境中的可移动物体相关联的特性。(An ultra-wideband based system and method for detecting characteristics associated with a movable object in an environment, such as an indoor environment. The method includes transmitting an ultra-wideband radar signal to an environment using an ultra-wideband transmitter, and receiving a plurality of signals reflected from the environment as a result of the transmission of the first ultra-wideband radar signal using an ultra-wideband receiver. The method also includes processing the reflected plurality of signals using a processor and determining a characteristic associated with a movable object in the environment based on the processed reflected signals.)

1. An ultra-wideband-based method for detecting a characteristic associated with a movable object in an environment, comprising:

transmitting a plurality of first ultra-wideband radar signals into an environment using a first ultra-wideband transmitter;

receiving, using a first ultra-wideband receiver, a plurality of first signals reflected from the environment as a result of transmission of the first ultra-wideband radar signal;

processing the reflected first signal using a processor; and

determining, using a processor, a characteristic associated with a movable object in the environment based on the processed reflected first signal.

2. The method of claim 1, wherein the determining step comprises determining the presence of the movable object in the environment.

3. The method of claim 1, wherein the processing step comprises removing a reference background signal from each reflected first signal.

4. The method of claim 1, wherein the processing step comprises determining a respective difference between each two temporally adjacent reflected first signals.

5. The method of any of claims 1-4, wherein the determining step comprises determining a distance between the movable object and the first ultra-wideband receiver.

6. The method of claim 5, wherein the determining step further comprises determining a change in distance between the movable object and the first ultra-wideband receiver.

7. The method of any one of claims 1 to 4, the processing step further comprising analyzing at least one of a signal strength and a frequency of the processed reflected first signal.

8. The method of claim 7, further comprising classifying the movable object as being in an active state or an inactive state based on the analysis.

9. The method of claim 8, wherein the step of classifying comprises comparing the processed reflected first signal to a classification threshold.

10. The method of claim 9, wherein the classification threshold depends on a distance between the movable object and the first ultra-wideband receiver.

11. The method of claim 10, further comprising adjusting a classification threshold based on a signal strength of the processed reflected first signal.

12. The method of claim 7, wherein analyzing the frequency of the processed reflected first signal comprises:

segmenting the processed reflected first signal to analyze only portions of the processed reflected first signal determined to be associated with the movable object.

13. The method of claim 7, wherein the movable object is a human or animal, and wherein the determining step further comprises determining a respiratory rate of the human or animal based on the frequency analysis.

14. The method of any of claims 1 to 4, further comprising:

transmitting a plurality of second ultra-wideband radar signals into the environment using a second ultra-wideband transmitter;

receiving, using a second ultra-wideband receiver, a plurality of second signals reflected from the environment as a result of the transmission of the second ultra-wideband radar signal; and

processing the reflected second signal using a processor;

wherein the determining step is further based on the processed reflected second signal.

15. The method of claim 14, wherein the processing of the reflected second signals includes removing a reference background signal from each reflected second signal.

16. The method of claim 14, wherein the processing of the reflected second signals comprises determining a respective difference between each two temporally adjacent reflected second signals.

17. The method of claim 14, wherein the determining step further comprises determining a distance between the movable object and the second ultra-wideband receiver based on the processed reflected second signal.

18. The method of claim 17, wherein the determining step further comprises determining a change in distance between the movable object and the second ultra-wideband receiver.

19. The method of claim 17, wherein the determining step further comprises determining a 2D position of the movable object in the environment based on the processed reflected first signal and the processed reflected second signal.

20. The method of claim 19, wherein the determining step further comprises determining a change in 2D position of the movable object in the environment.

21. The method of any of claims 1-4, wherein the first ultra-wideband transmitter and the first ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

22. The method of claim 14, wherein the second ultra-wideband transmitter and the second ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

23. The method of any one of claims 1 to 4, wherein the environment is an indoor environment.

24. The method of any one of claims 1 to 4, wherein the movable object is a human or animal.

25. An ultra-wideband-based system for detecting a characteristic associated with a movable object in an environment, comprising:

a first ultra-wideband transmitter for transmitting a plurality of first ultra-wideband radar signals to an environment;

a first ultra-wideband receiver for receiving a plurality of first signals reflected from the environment as a result of transmission of a first ultra-wideband radar signal;

one or more processors for processing the reflected first signal and for determining at least one of the following characteristics associated with a movable object in the environment:

a presence of a movable object in the environment based on the processed reflected first signal;

a distance between the movable object and the first ultra-wideband receiver;

a change in distance between the movable object and the first ultra-wideband receiver; and

whether the movable object is in an active state or an inactive state.

26. The ultra-wideband-based system of claim 25, wherein the first ultra-wideband transmitter and the first ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

27. The ultra-wideband-based system of claim 25 or 26, further comprising:

a second ultra-wideband transmitter for transmitting a plurality of second ultra-wideband radar signals to an environment; and

a second ultra-wideband receiver for receiving a plurality of second signals reflected from the environment as a result of transmission of a second ultra-wideband radar signal;

wherein the one or more processors are to process the reflected second signal;

wherein the one or more processors are further arranged to determine at least one of the following characteristics associated with the movable object in the environment based on processing of one or both of the reflected first signal and the reflected second signal:

the presence of a movable object in the environment based on the processed reflected second signal;

a distance between the movable object and the second ultra-wideband receiver;

a change in distance between the movable object and the second ultra-wideband receiver;

a 2D position of a movable object in the environment; and

a change in 2D position of a movable object in the environment.

28. The ultra-wideband-based system of claim 27, wherein the second ultra-wideband transmitter and the second ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

Technical Field

The present invention relates to systems and methods for detecting characteristics associated with movable objects in an environment using ultra-wideband radar signals.

Background

Systems and methods for detecting the position of an object are known. One type of system and method uses automatic image processing of data captured by a camera. Such systems and methods typically require a large amount of computing power to function properly and, in some cases, can pose privacy concerns. Another class of systems and methods is based on tags and anchors, i.e. wearable devices (tags) carried by the target object and adapted to transmit location information to a base station (anchor) using, for example, RFID or other near field technology. For the tag and anchor types to function, the target object must wear or carry a wearable device at the time of measurement. This seems to be commonplace, but remembering to wear or carry a device may not be easy for a target object such as an elderly person or a patient with senile dementia.

Disclosure of Invention

It is an object of the present invention to address the above-mentioned needs, overcome or substantially ameliorate the above disadvantages, or more generally, to provide an alternative or improved system and method for detecting a characteristic associated with a movable object in an environment.

According to a first aspect of the present invention there is provided an ultra-wideband based method for detecting a characteristic relating to a movable object in an environment, comprising: transmitting a plurality of first ultra-wideband radar signals into an environment using a first ultra-wideband transmitter; receiving, using a first ultra-wideband receiver, a plurality of first signals reflected from the environment as a result of transmission of the first ultra-wideband radar signal; processing the reflected first signal using a processor; and determining, using a processor, a characteristic associated with a movable object in the environment based on the processed reflected first signal.

In an embodiment of the first aspect, the determining step comprises determining the presence (or absence) of a movable object in the environment.

In an embodiment of the first aspect, the processing step comprises removing a reference background signal from each reflected first signal. The reference background signal may be predetermined (fixed). Optionally, the reference background signal may be adjusted in operation (e.g., based on the reflected first signal).

In an embodiment of the first aspect, the processing step comprises determining a respective difference between each two temporally adjacent reflected first signals. This involves identifying signal components that have changed between adjacent frames of the reflected first signal.

In an embodiment of the first aspect, the determining step comprises determining a distance between the movable object and the first ultra-wideband receiver based on the processed reflected first signal.

In an embodiment of the first aspect, the determining step further comprises determining a change in distance between the movable object and the first ultra-wideband receiver. By determining the change in distance, the trend of movement of the movable object (towards or away from the receiver) can be tracked.

In an embodiment of the first aspect, the processing step further comprises analyzing at least one of a signal strength and a frequency of the processed reflected first signal. Various signal processing techniques may be used in the analysis, such as domain transformation, thresholding, filtering, scaling, and the like.

In an embodiment of the first aspect, the method further comprises classifying the movable object as being in an active state or an inactive state based on the analysis.

In an embodiment of the first aspect, the step of classifying comprises comparing the processed reflected first signal with a classification threshold. The object is considered to be in an active state if it is determined that the processed reflected first signal is above a classification threshold. The object is considered to be in an inactive state if it is determined that the processed reflected first signal is below the classification threshold. When the processed reflected first signal is equal to the classification threshold, the object may be considered to be in an active state or in an inactive state. In some embodiments, for example, multiple classification thresholds may be used to better and more finely classify the activity level of an object.

In an embodiment of the first aspect, the classification threshold depends on a distance between the movable object and the first ultra-wideband receiver. For example, when the distance is determined to be within a first predetermined distance range, a first classification threshold is used, and when the distance is determined to be within a second predetermined distance range (different from the first predetermined distance range), a second classification use threshold (different from the first classification threshold) is used. In practice, each distance range may refer to a respective area in the environment, each area may have different settings and functions, such that the object has a different activity level.

In an embodiment of the first aspect, the method further comprises adjusting the classification threshold based on a signal strength of the processed reflected first signal.

In an embodiment of the first aspect, analyzing the frequency of the processed reflected first signal comprises: segmenting the processed reflected first signal to analyze only portions of the processed reflected first signal determined to be associated with the movable object. This reduces the computational power required for subsequent signal processing.

In an embodiment of the first aspect, analyzing the frequency of the processed reflected first signal comprises: analyzing the frequency of the processed reflected first signal may further comprise analyzing a change in a frequency spectrum of a series of processed reflected first signals.

In an embodiment of the first aspect, the movable object is a human or an animal, and the determining step further comprises determining a respiratory rate of the human or animal based on the frequency analysis.

In one embodiment of the first aspect, the method further comprises transmitting a plurality of second ultra-wideband radar signals to the environment using a second ultra-wideband transmitter; receiving, using a second ultra-wideband receiver, a plurality of second signals reflected from the environment as a result of the transmission of the second ultra-wideband radar signal; and processing the reflected second signal using a processor. Determining the characteristic associated with the movable object in the environment is further based on the processed reflected second signal.

In an embodiment of the first aspect, the processing of the reflected second signals comprises removing a reference background signal from each reflected second signal. The reference background signal may be predetermined (fixed). Alternatively, the reference background signal may be adjusted on the fly, e.g. based on the reflected second signal.

In an embodiment of the first aspect, the processing of the reflected second signals comprises determining a respective difference between every two temporally adjacent reflected second signals. This involves identifying signal components that have changed between adjacent reflected second signal frames.

In an embodiment of the first aspect, the determining step further comprises determining a distance between the movable object and the second ultra-wideband receiver based on the processed reflected second signal.

In an embodiment of the first aspect, the determining step further comprises determining a change in distance between the movable object and the second ultra-wideband receiver. By determining the change in distance, the trend of movement of the movable object (towards or away from the receiver) can be tracked.

In an embodiment of the first aspect, the determining step further comprises determining the 2D position of the movable object in the environment based on the processed reflected first signal and the processed reflected second signal. For example, a 2D position may be determined based on the determined distance (or change in distance) between the movable object and a first ultra-wideband receiver and the determined distance (or change in distance) between the movable object and a second ultra-wideband receiver (assuming that the relative position or distance between the two ultra-wideband receivers is known).

In an embodiment of the first aspect, the determining step further comprises determining a change in 2D position of the movable object in the environment. By determining the change in 2D position, the path of movement of the movable object can be tracked.

In one embodiment of the first aspect, the first ultra-wideband transmitter and the first ultra-wideband receiver are arranged in a single first ultra-wideband transceiver; a second ultra-wideband transmitter and a second ultra-wideband receiver are disposed in a single second ultra-wideband transceiver. The first and second ultra-wideband transceivers may each be separate units and operatively connected to each other. Or the first and second ultra-wideband transceivers may be arranged in the same unit. The first and second ultra-wideband transceivers may preferably communicate with an external electronic device (computer, telephone, tablet, server, etc.) through a wired or wireless communication network.

In one embodiment of the first aspect, the environment is an indoor environment, e.g. in a building; the movable object is a human or an animal. In one example, the environment is a senior home and the movable object is a senior. In another example, the environment is a ward of a hospital and the movable object is a patient.

According to a second aspect of the present invention, there is provided an ultra-wideband based system for detecting a characteristic associated with a movable object in an environment. An ultra-wideband based system may be implemented to perform the method of the first aspect. An ultra-wideband based system comprising: a first ultra-wideband transmitter for transmitting a plurality of first ultra-wideband radar signals to an environment; a first ultra-wideband receiver for receiving a plurality of first signals reflected from the environment as a result of transmission of a first ultra-wideband radar signal; one or more processors for processing the reflected first signal and for determining at least one of the following characteristics associated with a movable object in the environment: a presence of a movable object in the environment based on the processed reflected first signal; a distance between the movable object and the first ultra-wideband receiver; a change in distance between the movable object and the first ultra-wideband receiver; and whether the movable object is in an active state or an inactive state.

In one embodiment of the second aspect, the ultra-wideband-based system further comprises: a second ultra-wideband transmitter for transmitting a plurality of second ultra-wideband radar signals to the environment; a second ultra-wideband receiver for receiving a plurality of second signals reflected from the environment as a result of the transmission of the second ultra-wideband radar signal. The one or more processors are arranged to process the reflected second signal. The one or more processors are further arranged to determine at least one of the following characteristics associated with the movable object in the environment based on processing of one or both of the reflected first signal and the reflected second signal: the presence of a movable object in the environment based on the processed reflected second signal; a distance between the movable object and the second ultra-wideband receiver; a change in distance between the movable object and the second ultra-wideband receiver; a 2D position of a movable object in the environment; and a change in the 2D position of the movable object in the environment.

In an embodiment of the second aspect, the one or more processors operatively connected to each other may be distributed between different devices/units or integrated in the same device/unit.

In one embodiment of the second aspect, the first ultra-wideband transmitter and the first ultra-wideband receiver are arranged in a single first ultra-wideband transceiver; a second ultra-wideband transmitter and a second ultra-wideband receiver are disposed in a single second ultra-wideband transceiver. The first and second ultra-wideband transceivers may each be separate units and operatively connected to each other. Or the first and second ultra-wideband transceivers may be arranged in the same unit. The first and second ultra-wideband transceivers may preferably communicate with an external electronic device (computer, telephone, tablet, server, etc.) through a wired or wireless communication network.

Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagram of an environment in which an ultra-wideband based detection system is implemented, according to one embodiment of the invention;

FIG. 2 is a functional block diagram of an ultra-wideband unit in the ultra-wideband based detection system of FIG. 1, in accordance with one embodiment of the present invention;

FIG. 3 is a flow chart of a method of detecting a characteristic associated with a movable object in an environment using the ultra-wideband based detection system of FIG. 1;

FIG. 4A is a graph showing a received signal frame (as a result of transmitting an ultra-wideband radar signal), which also shows removal of background signals;

FIG. 4B is a graph illustrating a waveform (profile) of a processed radar frame, which also illustrates detection of a target (e.g., a movable object);

FIG. 4C is a graph showing the frequency relationship of the waveforms in FIG. 4B; and

figure 5 is a schematic diagram of a system including the ultra-wideband based detection system of figure 1, according to one embodiment of the invention.

Detailed Description

FIG. 1 illustrates an environment 10 having an ultra-wideband based detection system installed, in accordance with one embodiment of the present invention. In this embodiment, the environment 10 is an indoor environment in the form of a room in a building. A movable object 20, such as a person, is located in the room 10. An ultra-wideband based detection system comprises two ultra-wideband units 100A, 100B, each having a respective ultra-wideband transmitter for transmitting ultra-wideband radar signals and a respective receiver for receiving signals reflected from the environment 10. The ultra-wideband based detection system is operable to determine characteristics of a movable object 20 in the environment 10.

Figure 2 is a block diagram of the major components of an ultra-wideband based unit 200, according to one embodiment of the present invention. Each ultra-wideband unit 100A, 100B in fig. 1 may have the same basic structure as the unit 200 of fig. 2. The cell 200 may have a different configuration. Also, it may be implemented in a single device or distributed among a plurality of devices operatively connected together. Unit 200 typically includes appropriate components necessary to receive, store, and execute appropriate computer instructions, commands, or code. In this embodiment, the main components of the unit 200 include a UWB transceiver 201 having a transmitter 201T and a receiver 201R. The transmitter 201T and the receiver 201R may be the same component, or they may be different components. Unit 200 also includes a processor 202 and a memory 204. The processor 202 may be formed from one or more CPUs, MCUs, controllers, logic circuits, raspberry chips, and the like. The memory 204 may include one or more volatile memory units (such as RAM, DRAM, SRAM), one or more non-volatile memory units (such as ROM, PROM, EPROM, EEPROM, FRAM, MRAM, FLASH, SSD, NAND, and NVDIMM), or any combination thereof. Unit 200 may also include one or more input devices 206, such as a keyboard, a mouse, a stylus, an image scanner, a microphone, a tactile input device (e.g., a touch-sensitive screen), and an image/video input device (e.g., a camera). Unit 200 may also include one or more output devices 208, such as one or more displays (e.g., monitors), speakers, disk drives, headphones, earphones, printers, 3D printers, and so forth. The display may comprise an LCD display, an LED/OLED display, or any other suitable display that may or may not be touch sensitive. The unit 200 may also include one or more magnetic disk drives 212, which may include a solid state drive, a hard disk drive, an optical disk drive, a flash drive, and/or a tape drive. A suitable operating system may be installed in unit 200, for example, on disk drive 212 or in memory 204. The components of unit 200 may be operated by processor 202. Unit 200 also includes a communication module 210 for establishing one or more communication links (not shown) with one or more other external computing devices, such as a server, personal computer, terminal, tablet, telephone, or other wireless or handheld computing device. The communication module 210 may also establish communication links between different units 200 to enable communication between the units 200. The communication module 210 may be a modem, a Network Interface Card (NIC), an integrated network interface, a radio frequency transceiver, an optical port, an infrared port, a USB connection, or other wired or wireless communication interface. The communication link, which may be wired or wireless, is used to communicate commands, instructions, information and/or data. The transceiver 201, processor 202, memory 204, input device 206, output device 208, communication module 210, and disk drive 212 are interconnected by a bus, a Peripheral Component Interconnect (PCI) (such as PCI Express), a Universal Serial Bus (USB), an optical bus, or other similar data and/or power bus. Although not shown, the unit 200 may be powered by a DC power source (e.g., battery cells, battery packs) or an AC power source (e.g., having a power cord and plug for connecting to an AC power outlet). The unit 200 may also be connected to one or more external data stores or servers via a communication module 210.

Those skilled in the art will appreciate that the cell 200 shown in fig. 2 is merely exemplary. For example, the number of transceivers 201 in a unit may be more than one. The transmitter 201T and the receiver 201R may be arranged separately, rather than as a single transceiver 201. In one example, when multiple units 200 are operatively connected to one another (e.g., as shown in fig. 1), one of the units 200 may be a master unit 200 and the other units 200 may be slave units controlled by the master unit. The processor of the master unit may control the operation of the processor of the slave unit, while data and signal processing may be performed on any processor. In some embodiments, the transmitter 201T and receiver 201R or transceiver 201 may be arranged separately from other components of the unit 200.

FIG. 3 illustrates a method 300 of detecting a characteristic associated with an object 20 in an environment 10 using the ultra-wideband-based detection system of FIG. 1, in accordance with one embodiment of the present invention.

The method 300 begins at step 302, where an ultra-wideband radar signal is transmitted to the environment 10. In one embodiment, the transmission may be performed by an ultra-wideband transmitter of only one of the units 100A, 100B. In another embodiment, the transmission may be performed by the ultra-wideband transmitters of both units 100A, 100B. The transmissions of the two units 100A, 100B may be performed substantially simultaneously, or may be performed one after the other (with a known time difference), controlled by the processor of one or both of the units 100A, 100B.

The method 300 then proceeds to step 304, where a signal reflected from the environment 10 due to the transmission of the ultra-wideband radar signal is received. In embodiments where transmission is performed by an ultra-wideband transmitter of only one of the units 100A, 100B, the receiver of the respective unit will receive the reflected signal. In embodiments where the transmission is performed by the ultra-wideband transmitters of both units 100A, 100B, the receivers of both units 100A, 100B will receive the respective reflected signals. The reflected signal contains information about the environment 10, including the objects 20 in the environment 10.

Subsequently, in step 306, the reflected signal is analyzed. The analysis may be performed by a processor of the unit 100A, 100B receiving the reflected signal, or by any other processor operatively connected to the unit 100A, 100B. In embodiments where transmission and reception is performed by only one of the units 100A, 100B, the processor of the respective unit will analyze the received reflected signal. In embodiments where the transmission is performed by the ultra-wideband transmitters of both units 100A, 100B, the processors of both units 100A, 100B will process the reflected signals received separately. The processing may include removing a reference background signal from each of the reflected signals. The reference background signal may be predetermined (fixed) or may be adjusted in operation based on the characteristics (intensity, frequency, phase, etc.) of the reflected signal. Alternatively or additionally, the processing may include identifying signal components that have changed between adjacent frames of the reflected signal to determine a respective difference between each two temporally adjacent reflected first signals. As more and more reflected signals are processed, a time waveform may be established. The processing also involves analyzing the signal strength or frequency (or both) of the processed (e.g., background signal removed) reflected first signal using methods such as frequency-to-time domain transformation, thresholding (e.g., based on variations in noise in the signal), filtering, scaling, time gain compensation, etc. In one example, analyzing the frequency of the processed reflected signal involves segmenting the processed reflected first signal to analyze only the portion of the processed reflected first signal determined to be associated with the movable object.

In processing the received signals, in step 308, characteristics associated with movable object 20 in environment 10 are determined. This determination may be performed by the processor of the unit 100A, 100B performing the processing step in step 306, or by any other processor operatively connected to the unit 100A, 100B.

The characteristic associated with the movable object 20 in the environment 10 may be the presence (or absence) of the movable object 20 in the environment 10. This may be determined based on the processed signal. If the processed signal does not contain a temporally varying signal component, the object 20 is deemed to be absent from the environment 10. In one embodiment, even if the processed signal contains temporally varying signal components, the processed signal is compared to a predetermined reference signal to determine whether the object 20 is present or absent in the environment 10. The determination of the presence (or absence) of the movable object 20 may be performed using only one unit 100A, 100B.

The characteristic associated with the movable object 20 in the environment 10 may be a distance between the movable object 20 and one of the cells 100A, 100B. This may be determined based on the processed signal, based on time difference ranging, or similar techniques. The determination of the distance may be performed by only one unit 100A, 100B (and thus only one distance) or using two units 100A, 100B (determining the respective distances). By monitoring the processed signals over time, it is also possible to determine the change in distance between the movable object 20 and either of the units 100A, 100B.

In one embodiment, where both units 100A, 100B determine respective distances (or changes in respective distances), the characteristic associated with the movable object 20 in the environment 10 may be a 2D position of the object 20 in the environment 10. The 2D position may be determined based on the determined distance (or change in distance) between the movable object 20 and the unit 100A and the determined distance (or change in distance) between the movable object 20 and the unit 100B, assuming that the relative position or distance between the two ultra-wideband receivers of the units 100A, 100B is known. By monitoring the changes over time in the processed signals, changes in the 2D position of movable object 20 in environment 10 can be determined, and thus the path of movement of object 20 can be tracked.

In one embodiment where the movable object is a human or animal, the characteristic associated with the movable object 20 in the environment 10 may be the respiratory rate of the human or animal. The respiration rate may be determined based on a frequency analysis of the processed received signal.

Method 300 with steps 306 and 308 may be used to classify whether object 20 is in an active state (e.g., doing exercise) or an inactive state (e.g., sleeping). The classification may include comparing the processed reflected signal to a classification threshold. If it is determined that the processed reflected first signal is above the classification threshold, the object 20 is considered to be in an active state. If it is determined that the processed reflected first signal is below the classification threshold, the object 20 is considered to be in an inactive state. In some embodiments, multiple classification thresholds may be used to better and more finely classify the activity level of an object. In one embodiment, the classification threshold is different for different ranges of distances between the movable object and the units 100A, 100B. For example, when the distance is determined to be 0m to 80m (e.g., area a in fig. 1), a first classification threshold is used, and when the distance is determined to be 80m to 100m (e.g., area B in fig. 1), a second classification threshold different from the first classification threshold is used. The different areas may represent different areas (e.g., bedrooms, bathrooms, kitchens, etc.) in which object 20 is to perform different types of activities. The determination of the active and inactive states may also take into account the respiration rate of the object (based on the strength of the signal with respect to the respiration rate).

Figure 4A is a graph illustrating a frame of a signal received as a result of transmitting an ultra-wideband radar signal and removal of background signals, in accordance with one embodiment of the present invention. As shown in fig. 4A, the signal frame contains a background signal and a signal indicative of the condition of the environment 10 or the condition in the environment 10. The signal frames are processed by removing the background signal from the signal frames and optionally applying other signal processing or reconstruction techniques. By doing so, the resulting processed signal will be a "movement signal" that indicates a change in the condition of the environment 10 or a change in the condition in the environment 10 (e.g., a characteristic of the object 20).

Fig. 4B is a graph illustrating a waveform of a processed radar frame and target (e.g., movable object) detection based on the waveform. Fig. 4B may be obtained by assembling radar frames similar to fig. 4A and plotting them all in a single graph. In fig. 4B, a thick line encircled by a dotted line shows the recognized distance variation between the object 20 and the cell 100A or 100B.

Fig. 4C is a graph showing a frequency relationship of a part of the signal waveform in the graph of fig. 4B. For example, fig. 4C may be obtained by performing a short-time fast fourier transform on a portion of the waveform circled with a dashed line. The graph in fig. 4C shows the change in the extracted movement signal (movement rate) with time and time. The signals forming the map may be analyzed and processed to extract the respiration rate, and the strength of the signals may be used to set an activity level threshold of the system (e.g., as described above).

Figure 5 is a schematic diagram of a system including the ultra-wideband based detection system of figure 1 in one embodiment of the invention. As shown in fig. 5, the units 100A, 100B are operatively connected to one or more external electronic devices via the communication network 30. The communication network 30 may be wired or wireless (more preferred). The external electronic device 40 may be in the form of a computer server 40A, a smartphone/tablet 40B or a smart watch 40C. The basic structure of the external electronic device 40 is known, and it typically includes a processor, memory, I/O devices, communication modules, disk drives, etc. (e.g., similar to those described with reference to fig. 2). The system allows the units 100A, 100B to send data, alerts, information to the external electronic device 40 for viewing, analysis, storage, etc. In one example, if it is determined that the activity level of the object 20 is abruptly changed to 0 (which may indicate a fainting of the object 20), the units 100A, 100B may send an alert to the external electronic device 40 to notify a user or manager of the external electronic device 40 of such an event and take an emergency action.

Although not required, the embodiments described with reference to the figures may be implemented as an Application Programming Interface (API) or series of libraries used by developers or may be included in another software application, such as a terminal or personal computer operating system or portable computing device operating system. Generally, because program modules include routines, programs, objects, components, and data files that help to perform particular functions, those skilled in the art will appreciate that the functions of a software application may be distributed among multiple routines, objects, or components to achieve the same functionality as desired herein.

It should also be understood that any suitable computing system architecture may be used where the method and system of the present invention are implemented in whole or in part by a computing system. This would include stand-alone computers, network computers, dedicated or non-dedicated hardware devices. Where the terms "computing system" and "computing device" are used, these terms are intended to encompass any suitable arrangement of computers or information processing hardware capable of implementing the described functionality.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. For example, the ultra-wideband based system 100 may be formed from a single unit or more than two units (different from the units shown in fig. 1). The system 100 may be formed of a plurality of ultra-wideband based transmitter-receiver pairs/transceivers operatively connected with a single stand-alone computing device (laptop, desktop, etc.). The invention can be applied in outdoor environments. The movable object may be an animal. The invention may be applied in environments where there are multiple objects (not just one as shown). The described embodiments of the present invention are, therefore, to be considered in all respects as illustrative and not restrictive.