Autonomous Data Logger

Abstract

The present invention relates to a device for recording and storing measurement data related to an object or a living body. The device includes at least one sensor, a memory, and a controller. The at least one sensor is configured to measure data related to the object or the living body, and the controller is configured to store the measurement data in the memory. At least one photosensitive element is configured to convert electromagnetic radiation into an electric current. A transceiver is configured to transmit the measurement data and / or the stored data and receive data signals. At least one capacitor is configured to store the electric current from the at least one photosensitive element. The controller is configured to measure the voltage of the at least one capacitor. The controller is further configured to predict the output voltage of the at least one capacitor based on the measured voltage, and the controller is configured to increase or decrease the rate of sampling and storing the measurement data in the memory and / or increase or decrease the rate of transmitting the measurement data and / or the stored data according to the measured voltage or the predicted voltage.

Description

Technical Field

[0001] The present invention relates to devices, methods, and systems for recording, storing, and transmitting measurement data related to an object or a living being, such as an animal or a human. The present invention can also be used for objects that are passively exposed to environmental influences. Background Art

[0002] The term autonomous data recorder refers to a device capable of autonomously collecting data on a research subject. Such a device, particularly when tracking animals, is commonly referred to as a biologger, and can collect and provide data on the behavior of an animal or object. Generally, such a system includes a housing, electronics, an energy storage device or power source, embedded microcontroller software, and (if applicable) a solar cell for energy generation. In this way, the device can autonomously collect data on the research subject. The biologger is attached to an object or animal (e.g., worn as a backpack, ankle bracelet, or collar), and thus data on the behavior of the corresponding animal can be collected. Ideally, the animal wears the biologger throughout its life cycle in order to provide data over a long period of time without having to capture the animal multiple times.

[0003] Biologgers according to the prior art utilize lithium batteries as the main energy source. However, rechargeable lithium batteries require electronics, such as a low dropout regulator (LDO) or a direct current / direct current (DC / DC) converter, in order to maintain a constant operating voltage. Additionally, in order to charge the lithium battery, particularly through a solar cell, components specifically adapted for safe charging are required, and these components further increase the weight and the space required for the device due to the need for coils and passive elements. Moreover, circuits for preventing overcharging, deep discharging, and trickle charging of the battery must be included. However, these electronics increase the weight of the system, and thus make the device less comfortable for an animal to wear. Summary of the Invention

[0004] Accordingly, an object of the present disclosure is to overcome the disadvantages of the prior art. In particular, a lightweight device, such as a device mounted on an animal, is provided, which is powered only by one or more capacitors and one or more photosensitive elements (preferably, an array of photodiodes), and provides various advantages over lithium batteries as a state-of-the-art power supply technology for long-term biologgers. The present disclosure meets this object. The concept combines and tightly integrates an ultra-low power and ultra-lightweight hardware design with embedded software in order to intelligently budget the available energy of supercapacitors as the main power source. The energy is used to power an adaptive, event-driven activity monitoring algorithm, such as based on continuously evaluated acceleration data as a measure of activity.

[0005] In particular, the present invention relates to a device for recording and storing measurement data related to an object or a living body. The device includes: at least one sensor configured to measure data related to the object or the living body; a memory; and a controller configured to store the measurement data in the memory. At least one photosensitive element is configured to convert electromagnetic radiation into an electric current. A transceiver is configured to transmit the measurement data and / or the stored data and receive data signals. At least one capacitor is configured to store the electric current from the at least one photosensitive element.

[0006] Preferably, the various embodiments can implement the following features.

[0007] Preferably, the controller is configured to measure the voltage of the at least one capacitor.

[0008] Preferably, the controller is configured to predict the output voltage of the at least one capacitor based on the measured voltage, and the controller is configured to increase or decrease the rate of sampling and storing the measurement data in the memory and / or increase or decrease the rate of transmitting the measurement data and / or storing the data according to the measured voltage or the predicted voltage.

[0009] Preferably, the rate of sampling and storing the measurement data in the memory and / or the rate of transmitting the measurement data and / or storing the data is the highest at the maximum measured voltage or the predicted voltage and the lowest at the minimum measured voltage or the predicted voltage, wherein preferably the maximum voltage is the rated voltage of the capacitor and the minimum voltage is 0.66 of the maximum voltage.

[0010] Preferably, the device further includes a real-time clock RTC, wherein the RTC preferably operates independently of the controller.

[0011] Preferably, the controller is configured to power off at least one of the at least one sensor, the memory, or the transceiver when the measured voltage of the at least one capacitor is lower than the minimum voltage.

[0012] Preferably, the controller is configured to receive a wake-up signal from the RTC and measure the voltage of the at least one capacitor when the wake-up signal is received.

[0013] Preferably, the device includes a plurality of photosensitive elements, preferably photosensitive elements arranged in series.

[0014] Preferably, the open-circuit voltage of the photosensitive element or the sum of the open-circuit voltages of the plurality of photosensitive elements is higher than the rated voltage of the capacitor, wherein preferably the rated voltage of the capacitor is between 0.6 and 0.8 of the open-circuit voltage of the photosensitive element or the sum of the open-circuit voltages of the plurality of photosensitive elements, and the rated voltage of the capacitor is more preferably 0.75 of the open-circuit voltage of the photosensitive element.

[0015] Preferably, the at least one photosensitive element is a photodiode or includes a photodiode, wherein, preferably, the wavelength of the maximum sensitivity of the at least one photosensitive element is between 200 nm and 3000 nm, preferably between 400 nm and 1100 nm, and / or wherein the capacitor has a capacitance between 0.2 and 50 farads.

[0016] Preferably, the transceiver is a long-range wide area network module or a Bluetooth Low Energy module, or the transceiver includes a long-range wide area network module or a Bluetooth Low Energy module, and / or the at least one sensor is at least one of a gyroscope, an acceleration sensor, a temperature sensor, a humidity sensor, a magnetometer, a barometer, a light sensor, a volatile organic compound (VOC) sensor, or a Global Navigation Satellite System (GNSS) module, or the at least one sensor includes at least one of a gyroscope, an acceleration sensor, a temperature sensor, a humidity sensor, a magnetometer, a barometer, a light sensor, a volatile organic compound (VOC) sensor, or a Global Navigation Satellite System (GNSS) module.

[0017] Preferably, the device further includes at least one of a collar, a harness, a leg band, an ear tag, a backpack, a strap, a screw, glue, or a claw configured to be attached to the object or the living body.

[0018] Preferably, the device further includes a printed circuit board (PCB), wherein the at least one sensor, the memory, the controller, the at least one photosensitive element, the transceiver, and the capacitor are directly soldered to the PCB in one assembly step, preferably directly soldered to the PCB by reflow soldering in one assembly step.

[0019] The present disclosure also relates to a system including at least two devices as described above, wherein the controller of at least one of the at least two devices is configured to estimate the relative position of the at least one device with respect to at least one other device of the at least two devices using the received signal strength indication (RSSI) of a signal received from at least one other device of the at least two devices.

[0020] Preferably, the at least one device is configured to send data signals to and receive data signals from at least one other device, or the system further includes at least one base station configured to send data signals to and receive data signals from the at least one device.

[0021] The present disclosure also includes a method for recording and storing measurement data related to an object or a living body. The method includes measuring data related to the object or the living body by at least one sensor, storing the measurement data in a memory by a controller, and converting electromagnetic radiation into an electric current by at least one photosensitive element. The measurement data and / or the stored data are sent and data signals are received by a transceiver. The electric current from the at least one photosensitive element is stored in at least one capacitor. The voltage of the at least one capacitor is measured, and the output voltage of the at least one capacitor is predicted based on the measured voltage. The method further includes increasing or decreasing the rate of sampling and storing the measurement data in the memory and / or increasing or decreasing the rate of sending the measurement data and / or storing the data according to the measured voltage or the predicted voltage.

[0022] The rate of sampling and storing the measurement data in the memory and / or the rate of sending the measurement data and / or storing the data can be the highest at the maximum measured voltage or the predicted voltage and the lowest at the minimum measured voltage or the predicted voltage.

[0023] The method preferably further includes generating statistical data of the measurement data by the controller and storing the statistical data in the memory. Description of the Drawings

[0024] The present disclosure is further described with reference to the drawings.

[0025] Figure 1 is a schematic depiction of a biorecorder according to the prior art,

[0026] Figure 2 is a schematic depiction of a recording device according to an example of the present disclosure, and

[0027] Figure 3 is a schematic depiction of a recording device according to an example of the present disclosure. Detailed Description of the Invention

[0028] Figure 1 A schematic diagram of a biorecorder according to the prior art is shown. One or more solar cells 1 for generating energy are installed in or on a housing and are connected to a lithium polymer battery 3 through a battery management system 2. The battery management system 2 is also connected to electronic devices and distributes energy to the electronic devices, which are composed of a microcontroller 4, a memory 5, a communication module 6, and a sensor 7. The communication module 6 and the sensor 7 are also connected to an antenna 8 and a cable connection 9, as shown. A housing sealing element protects them from environmental influences and damage.

[0029] In this document, the microcontroller 4 controls the sensor 7 and the communication module 6. Typically, when the stored energy is sufficient for the operation of the biorecorder, data is collected, processed, and (temporarily) stored. Depending on the environment, data can be sent and / or received via a communication channel (e.g., for reconfiguration of the biorecorder). Subsequently, the system typically switches to the sleep mode (deep sleep) so as not to unnecessarily discharge the lithium polymer battery 3 and wakes up after a predetermined time interval. Some systems also utilize a standby mode where at least one communication module 6 is active and wakes up the biorecorder if certain radio signals are received.

[0030] In these systems, the battery management system 2 forms an autonomous unit that is decoupled from the core functions of the device. Thus, it continuously requires energy to monitor and protect the energy storage device (i.e., the lithium polymer battery 3). Conventional biorecorders read the battery state as an ADC signal and subsequently save it as a sensor value and / or transmit it as a state of health (SOH) value of the embedded system. If the remaining power allows, this information can also be used to switch to an energy-saving mode or perform energy-intensive operations such as data transmission or an attempt to obtain the current location via GPS. Conventional devices based on hardware or software usually shut down when the battery voltage is below a critical level.

[0031] However, the electronics required for energy management take up space, consume energy, and increase the weight of the system. In addition, due to the high-frequency switching of the converter, the circuit generates potential sources of interference for the RF module. Therefore, the present disclosure provides different charging, operating, and energy concepts for a biorecorder that is capable of autonomous operation over a long period while collecting behavioral data of an animal and managing the available energy.

[0032] Figure 2 is a schematic illustration according to an example of the present disclosure. The following examples will be described with reference to a device attached to a living animal. However, the present disclosure is not limited to this application and can also be used for other objects, e.g., objects exposed to environmental impacts such as waste residues.

[0033] An exemplary embodiment of the biorecorder includes a circuit board to which the remaining components are placed or attached. To generate energy, the biorecorder includes at least one photosensitive element, preferably an array of photosensitive elements 10, more preferably an array of photodiodes. Alternatively or additionally, solar cells can be used. When sunlight is incident on the photosensitive element 10, a charging current is generated to charge a capacitor 30, preferably a supercapacitor, used as an energy storage device. A Schottky diode can be arranged in the opposite direction with respect to the at least one photosensitive element to prevent the capacitor 30 from discharging via the photosensitive element 10.

[0034] The low-voltage supercapacitor 30 can be regarded as a volatile short-term energy buffer. According to this example, it is charged via an array 10 of photosensitive elements connected in series (an array of photodiodes or solar cells) (elements 10_1 to 10_X), where the total number of photosensitive elements 10, i.e., the total open-circuit voltage, is adapted to the maximum rated voltage of the capacitor 30. Under normal lighting conditions (i.e., average daylight conditions), the voltage of the photosensitive elements 10 is higher than the minimum voltage required for the operation of the biorecorder. This ensures that the capacitor 30 can also be charged under poor lighting conditions and the operation of the system is possible.

[0035] According to one embodiment, the capacitor 30 can also be charged within a few seconds by connecting it to an external energy source via at least one cable connection 90. The cable connection 90 can include multiple pins or various sockets and / or plugs. Due to its structural type, the charging and discharging current is limited only by the internal resistance of the capacitor 30.

[0036] Compared with the conventional method described above, this allows for a simple battery management system. In particular, a microcontroller 40 with software implemented thereon monitors the state of the capacitor 30 and allocates energy according to the charge state or sets the system to a sleep mode. The available energy is directly and functionally linked to the data collected by the biorecorder, thus allowing for an efficient use of excess energy. This can be referred to as software-based energy management.

[0037] The capacitor 30 supplies power to an electronic device part including a microcontroller 40, a memory 50, at least one communication module 60, and at least one sensor 70. The microcontroller 40 also serves as an energy management system or includes an energy management system through embedded software. The at least one communication module 60 is configured to transmit and receive data wirelessly or via a wired connection. Therefore, it is connected to at least one antenna 80 and / or the at least one cable connection 90. The at least one antenna 80 is provided according to the desired communication method, which is, for example, Bluetooth Low Energy (Bluetooth LE), Low-Power Wide Area Network (LPWAN) (such as LoRa / LoRaWAN), or any other form of wireless transmission. In the case of using LoRa / LoRaWAN communication, a supercapacitor is preferred because it can provide the high current required for transmission. The at least one communication module 60 and the at least one antenna 80 can also be used for proximity detection, i.e., to detect whether there is another device and within what distance, for example, via Bluetooth LE and / or Received Signal Strength Indicator (RSSI). For communication purposes, a transceiver module 20 can be provided, which is provided as a single module or a combined module that includes at least one of the at least one communication module 60, the at least one antenna 80, or at least one cable connection 90.

[0038] The at least one sensor 70 is used to collect motion and environmental data as well as position data. Suitable sensors can be, but are not limited to, environmental sensors (temperature, humidity, atmospheric pressure (barometer), air quality (e.g., via volatile organic compounds (VOCs)), light sensors, 3-axis acceleration sensors (accelerometers), gyroscopes, magnetometers, global navigation satellite system (GNSS) sensors such as global positioning system (GPS), etc. These sensors provide valuable data regarding the motion and behavior of the animal or object.

[0039] The complete hardware system including the microcontroller 40, the memory 50, the communication module(s) 60, and the sensor(s) 70 (represented by the dashed line in Figure 2 is suitable for operating at a wide range of supply voltages, rendering the LDO or DC / DC converter for providing a constant supply voltage redundant. Thus, the number of hardware components is reduced, thereby reducing weight, lowering standby current, and improving energy supply efficiency. All components are operated directly through capacitors, as shown by the arrows in Figure 2 . Under this advantageous operation, it is generally not possible to use a lithium battery without a voltage regulator because a fully charged lithium battery supplies a voltage of, for example, 4.2V, which is higher than the maximum rated voltage of 3.6V for many microcontrollers and sensors.

[0040] To effectively manage the available energy, the operating concept is implemented as software on the microcontroller 40 for monitoring the charge state, i.e., the capacitor 30 voltage, and allocating energy or stopping operation. In particular, the energy management can act prophylactically and anticipatorily to avoid overcharging or deep discharging of the capacitor 30. Thus, the voltage of the capacitor 30 (assumed to be a 3V capacitor) is regulated within the range of 1.8 - 3V. This voltage range should not be construed as restrictive and can vary according to the specifications of the capacitor and the electronics.

[0041] Contrary to a lithium battery, by measuring the voltage of the capacitor 30, i.e., the voltage present at the capacitor 30, the load of the capacitor 30 can be determined very precisely with a low error tolerance due to its linear dependence on the capacitor voltage. Since the maximum charging current output by the photosensitive element 10 can also be calculated, the future energy state can be estimated considering the charging current as well as the capacitor voltage history.

[0042] Since checking the voltage present at capacitor 30 requires very little energy, the microprocessor 40 can wake up at specific intervals and determine the charge state of capacitor 30. Therefore, a real-time clock (RTC) that runs continuously and acts as a timer is provided. This allows the sensor intervals, wake-up intervals, measurement and evaluation intervals, etc. to be adapted dynamically to the current energy state, i.e., the available energy stored in capacitor 30. In particular, if the charge state of capacitor 30 is high, the intervals can be set shorter, i.e., the measurement / transmission / evaluation / wake-up frequency can be increased to continuous operation, and vice versa. When high light intensity is incident on the photosensitive element 10, preferably, the energy consumption of the electronic devices 40, 50, 60, 70 is equal to or higher than the maximum charging current generated by the photosensitive element 10 in order to ensure that capacitor 30 is not overcharged. Thus, when the end-of-charge (EOC) state is reached, the excess energy is not converted to heat as is typically done in conventional battery management systems, but can be effectively used to record data at a higher sampling frequency or transmit data at a higher frequency.

[0043] On the other hand, deep discharge of capacitor 30 must be avoided because the system may not be able to wake up from such a state. Therefore, the wake-up time interval for the microcontroller 40 to check the capacitor voltage increases. Depending on the environment, the microcontroller 40 can be set to the sleep mode for several hours or several days. The sleep mode affects all electrical loads of the device except the RTC, which simultaneously triggers the wake-up interval. However, preferably, the wake-up interval is set in such a way that even if a high charging current is input to capacitor 30 due to high light intensity, the microcontroller 40 wakes up early enough to prevent overcharging of capacitor 30.

[0044] The ratio of the wake-up / measurement / transmission / evaluation / sampling interval (or frequency) to the charge state can be pre-configured and embedded in the software stored on the microprocessor 40 and / or the memory 50. At least lower and higher thresholds are set at which the intervals increase and decrease respectively (at which the frequencies decrease and increase).

[0045] However, preferably, the software stored on the microprocessor 40 includes an increase in the wake-up / measurement / transmission / evaluation / sampling frequency as the charge state of capacitor 30 gradually increases. This can be achieved, for example, by implementing a mathematical relationship that describes the wake-up frequency as a function of the capacitor voltage.

[0046] Moreover, the microcontroller 40 can be configured to measure the voltage of the at least one capacitor 30 (present at the at least one capacitor 30), and based on the measured voltage, predict the output voltage of the at least one capacitor 30. Voltage is an indicator of the load and thus an indicator of the energy stored in the capacitor 30. The prediction can be based, for example, on the characteristics of the capacitor 30 and / or historical voltage data. It can also be based, for example, on the knowledge of the current local time and date provided by the RTC. At night, it can be assumed that due to the lack of light incident on the photosensitive element 10, the capacitor voltage will not increase. When the measured voltage reaches a first predetermined threshold and the predicted output voltage exceeds the first threshold, the microcontroller 40 can increase or decrease the rate of sampling and storing measurement data in the memory and / or increase or decrease the rate of transmitting measurement data and / or storing data according to the predicted voltage. The first threshold is lower than the rated voltage of the capacitor, preferably 0.9 of the rated voltage of the capacitor.

[0047] The microcontroller 40 is configured to power off at least one of the electronic components other than the RTC when the measured voltage of the capacitor 30 is lower than a second threshold, and / or power on at least one of the electronic components when the measured output voltage is higher than the second threshold.

[0048] The second threshold is lower than the rated voltage of the capacitor 30, preferably at least 0.6 of the rated voltage of the capacitor 30, more preferably 0.66 of the rated voltage of the capacitor 30.

[0049] However, preferably, a gradual increase or decrease in the wake-up / measurement / transmission / evaluation / sampling frequency is implemented in the microcontroller 40.

[0050] In other words, the microcontroller 40 is configured to predict the output voltage of the at least one capacitor 40 based on the measured voltage, and the microcontroller 40 is configured to increase or decrease the rate of sampling and storing measurement data in the memory and / or increase or decrease the rate of transmitting measurement data and / or storing data according to the predicted voltage. The rate of sampling and storing measurement data in the memory and / or the rate of transmitting measurement data and / or storing data is the highest at the maximum predicted voltage and the lowest at the minimum predicted voltage.

[0051] The maximum voltage can be the rated voltage of the capacitor 30, and the minimum voltage can be at least 0.6 of the maximum voltage, preferably the minimum voltage can be 0.66 of the maximum voltage.

[0052] The highest wake-up / measurement / transmission / evaluation / sampling frequency is the continuous operation of at least one electronic component, and the lowest frequency can be several hours or several days.

[0053] The RTC operates independently and is configured to monitor the wake-up interval. The RTC sends a wake-up signal that is received by the microcontroller 40, and the microcontroller 40 measures the voltage of the at least one capacitor 30 when the wake-up signal is received.

[0054] When the measured voltage of the capacitor 30 is below the minimum voltage, the microcontroller 40 is configured to power off at least one of the at least one sensor 70, the memory 50, or the transceivers 20, 60, 80, 90 when the measured voltage of the at least one capacitor 30 is below the minimum voltage. As described above, the wake-up interval can be set in a manner that avoids overcharging and discharging of the capacitor 30. The microcontroller 40 is woken up by the RTC at corresponding intervals to check or measure the voltage of the capacitor 30. This measurement process requires very little energy and thus only slightly affects the charge state of the capacitor 30.

[0055] In any case, the hardware composition needs to support an ultra-low power off mode in order to be able to resume the system after a sustained low power situation.

[0056] Adjacent devices or base stations can receive the wake-up interval from the biorecorder.

[0057] The data collected by the sensor 70 can be directly evaluated in the microprocessor 40 and stored as statistical data in the memory 50. This pre-processed data can save storage space and facilitate analysis at a later stage. Examples of data or sensor statistics that can be generated by the biorecorder are given below.

[0058] Data from the acceleration sensor can be stored for three axes, preferably on the internal memory of the sensor, where the sampling frequency can vary between below 1 Hz and 25 Hz depending on the charge state of the capacitor 30, as described above. When the internal memory is full, the microprocessor 40 can be woken up to collect and process the data from the acceleration sensor. Alternatively, a time interval can be set after which the microcontroller 40 wakes up to perform the processing, where the time interval can depend on the charge state of the capacitor 30. Subsequently, the data is processed to generate statistics of the acceleration values and stored in the memory 50.

[0059] Below, examples for evaluating the raw data are given. The time interval can be, for example, one hour and can be adjusted according to the charge state and / or the type of animal or object being monitored. The results are to be understood as examples, and other behavioral information can be obtained from the raw or statistical data.

[0060] The sum of the 3D vector lengths of the acceleration values in g (square root of the sum of squares) minus the gravity of the Earth per hour indicates the activity index of the animal or object for each time interval. This data can provide insights into the movement of a particular species over the course of a year, day, or season.

[0061] The maximum, minimum, median, and average accelerations in each of the three axes for each time interval also yield activity indices.

[0062] Depending on the type of animal, the number of steps or wing beats per time interval can be used to approximate the distance traveled by the animal through peak-to-peak counting or fast Fourier transform (FFT) and filtering.

[0063] Moreover, for example, based on a motion threshold, the ratio of motion to non-motion as a percentage for each time interval can be used to generate an activity profile and classify the behavior of the animal. The threshold can be set according to the type of animal being monitored.

[0064] Multiple exceedances of a threshold of the acceleration values (absolute value or per axis) for each time interval help to determine high-action, potentially stress-induced situations.

[0065] For birds, for example, based on data from a barometric pressure sensor, such as the maximum and minimum barometric pressures for each time interval, the flight altitude or dwelling time in the nest and on the ground can be approximated.

[0066] The ratio of humidity and temperature above a specific threshold for each time interval or the ratio of the maximum and minimum temperatures for each time interval can also provide information about the number and duration of stays in the nest or cave.

[0067] Based on proximity detection, such as via Bluetooth LE and / or RSSI, the number of conspecifics encountered can be recorded as long as they also wear a corresponding biorecorder. This number, as well as the minimum, maximum, and / or average distance for each time interval, can yield information about the social behavior of the species.

[0068] Statistical data can be generated by the microcontroller 40 and stored in the memory 50. Thus, storage space in the memory 50 is saved, and due to the smaller amount of data transmitted, the energy consumption for data transmission is lower. The generation of statistical data can also be performed using machine learning algorithms. The algorithm can be pre-trained or trained during the use of the biorecorder. Examples of training the algorithm can include extracting specific behavioral events of the animal, such as counting the number of steps or wing beats, detecting body postures, such as sitting, lying, standing, and / or detecting more complex action sequences, such as hunting or dying.

[0069] The electronic components are directly soldered onto a printed circuit board (PCB) having at least one layer or at the location of a printed circuit board (PCB) having at least one layer, thereby making the cable or wired connection redundant. In contrast to lithium batteries, (super) capacitors can be mounted using reflow soldering through vias or as surface mount devices (SMDs). The remaining components can also be provided as SMDs and connected using reflow soldering. Since cable connections are the main cause of system failures due to mechanical wear and vibrations during the use of the biorecorder, the direct mounting solution significantly increases the device's life cycle.

[0070] To protect the components from environmental influences such as water and dust, the device is painted and / or sprayed. This further strengthens the solder connections and reduces the weight compared to using a conventional housing. Care must be taken not to reduce the efficiency of the photosensitive components.

[0071] An exemplary setup for testing purposes utilizes eight BPW34 type photodiodes connected in series and mounted on a four-layer PCB. A 3V, 1F supercapacitor (SCCQ12E105PRB 3V) is connected to the PCB as an energy storage device and power supply. Assuming optimal lighting conditions, this particular capacitor can be charged from 1.8V to 3V in 630 seconds. A Schottky diode NSR0140P2T5G prevents the capacitor from discharging via the photodiodes. The Schottky diodes are arranged in an array facing the photodiodes in the opposite direction. As described above, overcharging and deep discharging are prevented by software. The test device is also characterized by an Attiny3217 8-bit microcontroller, a BME280 environmental sensor (ambient temperature, humidity, atmospheric pressure, air quality via VOC), and a BMA400 three-axis accelerometer. According to another example, an Attiny1616 8-bit microcontroller and a BME680 environmental sensor can be used. A CAT24M01HU5I-GT3 1M-bit electrically erasable programmable read-only memory (EEPROM) is provided as a memory, and an RV-3028-C7 RTC clock is used as an RTC. An ANNA-B112-01B Bluetooth low energy module is provided for communication. The circuit also includes LEDs and passive components as well as an AXE616124 multi-point connector for modular expansion of the system, programming of the microcontroller, and reading out of data. Additionally, according to one example, a VEML6035 light sensor can be provided for estimating and / or predicting the state of the device (e.g., charge state).

[0072] Figure 3 is a schematic diagram of the basic configuration of the device according to the present disclosure. Unless otherwise indicated, all components according to the Figure 2 example, especially the elements with the same reference numerals, can be used together with those in Figure 3 and vice versa. According toFigure 3 The device includes at least one photosensitive element 10 and a capacitor 30. The at least one photosensitive element 10 is configured to convert electromagnetic radiation into an electric current, and the capacitor 30 is charged by the electric current from the at least one photosensitive element 10. The device further includes a controller 40, a memory 50, and at least one sensor 70. To communicate with adjacent devices or a base station, transceivers 20, 60, 80, 90 are provided. The transceivers can send and receive data wirelessly or via a cable connection to transmit measurement data, communicate with other devices, such as for proximity detection, and receive reconfiguration data or updates for the controller 40.

[0073] The lightweight and waterproof device according to the present disclosure can be attached to an object or a living body, for example, by using a collar, a harness, a leg band, an ear tag, a backpack, a strap, a screw, glue, or a claw, throughout the entire life cycle of the living body or when needed.

[0074] The present disclosure also includes a system that includes at least two devices as described above. At least one device is configured to calculate the relative position of one device with respect to at least one other device using the received signal strength indication (RSSI) from the at least one other device. This can be achieved, for example, through Bluetooth Low Energy (LE) communication. If two devices are involved, the distance between the two devices can be approximately calculated, while at least three devices allow the determination of the relative position, i.e., the formation, without rotational information. The devices can also exchange the position information or send and receive other data from other devices.

[0075] For precise positioning, a base station or a gateway capable of communicating with at least one device can be established. Via the RSSI, the radial distance from the device to the base station can be approximately calculated. If the device is within the transmission and reception range of two base stations, two possible positions of the device can be determined, i.e., the intersection of two circles in a simplified two-dimensional space, where the radius is equal to the distance approximately calculated by the RSSI. In three-dimensional space, the intersection of two spheres is used to determine the possible position of the device. If the device can communicate with three or more base stations, the exact position can be calculated.

[0076] Due to the limited storage space on the memory 50, if the RSSI and the charging state of the capacitor allow, the device preferably transmits the collected data (raw data or preprocessed data as described above) to an adjacent base station. Subsequently, the data can be deleted from the memory 50 of the device.

[0077] The present disclosure also includes a method corresponding to the devices and systems described above. The method may specifically relate to battery management as described above. Additionally, the method may specifically include on-board processing of data. As described above, the device may process raw data to generate statistical data, thus saving storage space in the memory 50. The calculation of the statistical data may specifically be performed by the controller 40.

[0078] Motion metrics, i.e., the acquisition and processing of animal movement data, can also be achieved based on aggregated 3-axis acceleration data. An example of such processing is the vector of dynamic body acceleration (VeDBA), as in Qasem L, Cardew A, Wilson A, Griffiths I, Halsey LG, Shepard ELC et al. (2012) Tri-Axial Dynamic Acceleration as a Proxy for Animal Energy Expenditure; Should We Be Summing Values or Calculating the Vector? PLoS ONE 7(2): e31187. https: / / doi.org / 10.1371 / journal.pone.0031187 As disclosed. Alternatively, zero crossing and zero crossing average amplitude can be used, as in Seo, Jungryul & Chiang, Yutsai & Laine, Teemu & Khan, Adil. (2015), Step counting on smartphones using advanced zero-crossing and linear regression, ACM IMCOM 2015 – Proceedings. 10.1145 / 2701126.2701223( https: / / www.researchgate.net / publication / 282680705_Step_ counting_on_smartphones_using_advanced_zero-crossing_and_linear_regression ) As disclosed. If the dynamic acceleration is close to zero, pitch and roll estimation can be employed.

[0079] Furthermore, the rise and fall of the (super) capacitor voltage within a predetermined time window can be used for the estimation of sunlight exposure. For a 1F super capacitor, a time window of 30 seconds can be set, for example.

[0080] As an alternative data transmission method, a remote transmission module based on the Sigfox IoT network can be used. Sigfox can be used as an alternative to data acquisition via Bluetooth LE and allows the transmission of summarized acceleration and environmental data (atmospheric pressure, temperature, sunshine, etc.) as well as trilateration-based position estimation (i.e., an alternative to GPS, but less accurate).

[0081] For better power management, a circuit can be provided that cuts off the main power supply of the microcontroller and the integrated sensor / communication module once the voltage drops below a specific threshold. The threshold can be, for example, 2.1V, otherwise the microcontroller can remain reset with increased power consumption, and the device may not be able to recover from a low voltage situation due to insufficient power provided by the (one or more) photosensitive elements. This also works as a fallback solution in cases where the software cannot keep the voltage above a specific threshold (e.g., by intelligent adaptation of the sampling frequency).

[0082] Exemplary embodiments of the operational concept of not wasting the recovered energy can adopt the following thresholds. If the voltage of the (super) capacitor is higher than 2.6V, the device can transmit a wireless data message, e.g., a wireless remote SigFox message. In the case where the voltage drops below 2.2V, the device can be configured to hibernate, i.e., be moved to the sleep mode. Thus, the power consumption can be less than 500nA. When the voltage is higher than 2.2V, the device can operate again in the normal state, i.e., sample the sensor data and update the statistics / metrics as described above. This typically has a power consumption of about 2.5μA. The above thresholds and values are only examples and can be changed according to the properties of the device, components, or the environment in which the device is used.

[0083] The setup can also utilize a recovery circuit with a photodiode and an MPPT (maximum power point tracking) harvesting circuit, preferably in a boost configuration. The harvesting circuit used in this particular example is the AEM10941 with two photodiodes.

[0084] According to the present disclosure, improved devices, systems, and methods for recording and storing measurement data related to an object or a living body are proposed. By using a (super) capacitor as an energy source, the environmental impact of the device is minimized because the manufacturing of capacitors requires less energy and resources compared to lithium batteries. In addition, there is no risk of explosion or fire in the case of deep discharge, overcharge, deformation, penetration, or exposure to high temperatures of the capacitor. The electronic device does not pose any risk to the environment, humans, or animals.

[0085] Compared with lithium batteries, capacitors have a high operating temperature range and theoretically have an infinite number of charge and discharge cycles without performance loss. Therefore, the device can be worn for a longer time while still providing all functions. Capacitors can also be fully charged in seconds by an external power source, while lithium batteries may deteriorate due to continuous high charging currents.

[0086] Sensors such as cameras, environmental sensors, or communication modules (e.g., LPWAN) temporarily require a high operating current, which can be provided by capacitors even in small packages without damaging the capacitors. This allows the use of the latest electronics while minimizing the size and weight of the biorecorder. Small lithium batteries can provide a higher capacity, but have a lower discharge current.

[0087] Since all electronic components are directly powered by the energy from the capacitor, lossy components such as LDOs or DC / DC converters can be omitted, thus reducing the standby and operating currents. The reduction in the required components also results in a decrease in weight and cost. All components can be directly mounted on the PCB as SMDs using reflow soldering and are covered by a protective coating. No cables are required. Therefore, a housing for protecting the electronics is not needed. Through software-implemented energy management, excess energy is not converted into heat but is effectively used for data generation, transmission, and reception.

[0088] By processing the collected data on-board and only storing statistical data, the storage space can be used more efficiently and the evaluation of the data can be facilitated. In addition, due to the preprocessing, the transmission of the data can be less energy-consuming.

[0089] From the above overview and from the following description including the drawings and claims, other aspects, features, and advantages will be apparent.

[0090] Although the invention has been described in detail in the drawings and the foregoing description, such description and illustration shall be regarded as illustrative or exemplary and not restrictive. However, it should be understood that those of ordinary skill in the art can make changes and modifications within the scope of the appended claims. In particular, the invention covers further embodiments having any combination of features from different embodiments described above and below.

[0091] Furthermore, in the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single unit can implement the functions of several features described in the claims. Terms such as "substantially", "about", "approximate", etc. associated with an attribute or value also precisely define the attribute or the exact value. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An apparatus for recording and storing measurement data related to an object or a living body, the apparatus comprising: at least one sensor (70) configured to measure data related to the object or the living body; a memory (50); a controller (40) configured to store the measurement data in the memory (50); at least one photosensitive element (10) configured to convert electromagnetic radiation into an electric current; a transceiver (20, 60, 80, 90) configured to transmit the measurement data and / or the stored data and receive data signals; and at least one capacitor (30) configured to store the electric current from the at least one photosensitive element (10), wherein the controller (40) is configured to measure the voltage of the at least one capacitor (30), and wherein the controller (40) is configured to predict the output voltage of the at least one capacitor (30) based on the measured voltage, and wherein the controller (40) is configured to increase or decrease the rate of sampling and storing the measurement data in the memory (50) and increase or decrease the rate of transmitting the measurement data and / or storing the data according to the measured voltage or the predicted voltage.

2. The apparatus according to claim 1, wherein the rate of sampling and storing the measurement data in the memory (50) and / or the rate of transmitting the measurement data and / or storing the data is the highest at the maximum measured voltage or the maximum predicted voltage and the lowest at the minimum measured voltage or the minimum predicted voltage.

3. The apparatus according to claim 1, wherein the maximum voltage is the rated voltage of the capacitor (30), and the minimum voltage is 0.66 of the maximum voltage.

4. The apparatus according to claim 1, further comprising a real-time clock RTC, and wherein the controller (40) is configured to power off at least one of the at least one sensor (70), the memory (50) or the transceiver (20, 60, 80, 90) when the measured voltage of the at least one capacitor (30) is lower than the minimum voltage.

5. The apparatus according to claim 4, wherein the RTC operates independently of the controller (40).

6. The apparatus according to claim 4, wherein the controller (40) is configured to receive a wake-up signal from the RTC and measure the voltage of the at least one capacitor (30) when the wake-up signal is received.

7. The apparatus according to claim 3, further comprising a real-time clock RTC, and wherein the controller (40) is configured to power off at least one of the at least one sensor (70), the memory (50) or the transceiver (20, 60, 80, 90) when the measured voltage of the at least one capacitor (30) is lower than the minimum voltage.

8. The apparatus according to claim 7, wherein the RTC operates independently of the controller (40).

9. The apparatus according to claim 7, wherein The controller (40) is configured to receive a wake-up signal from the RTC and measure the voltage of the at least one capacitor (30) when the wake-up signal is received.

10. The device according to any one of claims 1 to 9, wherein, the device includes a plurality of photosensitive elements (10).

11. The device according to any one of claims 1 to 9, wherein, the device includes a plurality of photosensitive elements (10) arranged in series.

12. The device according to any one of claims 1 to 9, wherein, the open-circuit voltage of the photosensitive element (10) or the sum of the open-circuit voltages of the plurality of photosensitive elements (10) is higher than the rated voltage of the capacitor (30).

13. The device according to claim 12, wherein, the rated voltage of the capacitor (30) is between 0.6 and 0.8 of the open-circuit voltage of the photosensitive element (10) or the sum of the open-circuit voltages of the plurality of photosensitive elements (10).

14. The device according to claim 12, wherein, the rated voltage of the capacitor (30) is 0.75 of the open-circuit voltage of the photosensitive element (10).

15. The device according to any one of claims 1 to 9, wherein, the at least one photosensitive element (10) is a photodiode or includes a photodiode, and / or wherein, the capacitor (30) has a capacitance between 0.2 and 50 farads.

16. The device according to claim 15, wherein, the wavelength of the maximum sensitivity of the at least one photosensitive element (10) is between 200 nm and 3000 nm.

17. The device according to claim 16, wherein, the wavelength of the maximum sensitivity of the at least one photosensitive element (10) is between 400 nm and 1100 nm.

18. The device according to any one of claims 1 to 9, wherein, the transceiver (20, 60, 80, 90) is a remote wide area network module or a Bluetooth Low Energy module, or includes a remote wide area network module or a Bluetooth Low Energy module, and / or wherein, the at least one sensor (70) is at least one of a gyroscope, an acceleration sensor, a temperature sensor, a humidity sensor, a magnetometer, a barometer, a light sensor, a volatile organic compound VOC sensor, or a Global Navigation Satellite System GNSS module, or includes at least one of a gyroscope, an acceleration sensor, a temperature sensor, a humidity sensor, a magnetometer, a barometer, a light sensor, a volatile organic compound VOC sensor, or a Global Navigation Satellite System GNSS module.

19. The device according to any one of claims 1 to 9, further comprising at least one of a collar, a harness, a leg band, an ear tag, a backpack, a strap, a screw, glue, or a claw configured to be attached to the object or the living body.

20. The device according to any one of claims 1 to 9, further comprising a printed circuit board PCB, wherein, The at least one sensor (70), the memory (50), the controller (40), the at least one photosensitive element (10), the transceivers (20, 60, 80, 90) and the capacitor (30) are directly soldered to the PCB in one assembly step.

21. The device according to claim 20, wherein the at least one sensor (70), the memory (50), the controller (40), the at least one photosensitive element (10), the transceivers (20, 60, 80, 90) and the capacitor (30) are directly soldered to the PCB by reflow soldering in one assembly step.

22. A system for recording and storing measurement data related to an object or a living body, comprising at least two devices according to any one of claims 1 to 9, wherein, the controller (40) of at least one of the at least two devices is configured to estimate the relative position of the at least one device with respect to at least one other device of the at least two devices using the signal strength RSSI of a signal received from at least one other device of the at least two devices.

23. A system for recording and storing measurement data related to an object or a living body, comprising at least one device according to any one of claims 1 to 9, wherein, at least one device is configured to send a data signal to and receive a data signal from at least one other device, or wherein the system further comprises at least one base station configured to send a data signal to and receive a data signal from the at least one device.

24. A method for recording and storing measurement data related to an object or a living body, the method comprising measuring data related to the object or the living body by at least one sensor (70); storing the measurement data in a memory (50) by a controller (40); converting electromagnetic radiation into an electric current by at least one photosensitive element (10); sending the measurement data and / or the stored data and receiving a data signal by a transceiver (20, 60, 80, 90); storing the current from the at least one photosensitive element (10) in at least one capacitor (30); and measuring the voltage of the at least one capacitor (30); wherein the method further comprises predicting the output voltage of the at least one capacitor (30) based on the measured voltage, and increasing or decreasing the rate of sampling and storing the measurement data in the memory (50) and increasing or decreasing the rate of sending the measurement data and / or storing the data according to the measured voltage or the predicted voltage.

25. The method according to claim 24, wherein, the rate of sampling and storing the measurement data in the memory (50) and / or the rate of sending the measurement data and / or storing the data is highest at the maximum measured voltage or the maximum predicted voltage and lowest at the minimum measured voltage or the minimum predicted voltage.

26. The method according to claim 24 or 25, further comprising generating statistical data of the measurement data by the controller (40) and storing the statistical data in the memory (50).

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