CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Utility Application No. 14/790,953, filed July 2, 2015.

BACKGROUND

Due to rapidly increasing temperatures within a locked vehicle, children left in vehicles run a high risk of heat exhaustion or death. Existing solutions for child detection rely on weight sensors, however these weight sensors require weight calibration.

SUMMARY

Methods and systems for detection of child vehicle seats may be used to indicate presence or absence of a child in the vehicle. In some examples, an alarm system includes a radio frequency (RF) transceiver and a child seat with an integrated occupancy sensor. Various actions are triggered when the parent (e.g., guardian) goes beyond a predefined range while the occupancy sensor indicates the child seat is occupied, such as sounding an alarm on a mobile electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a child vehicle seat occupancy detection and notification system, according to some embodiments.

FIG 2A is a perspective view of a child vehicle seat detection and notification system, according to some embodiments.

FIG. 2B is a perspective view of a child vehicle seat occupancy detection and notification system, according to some embodiments. FIGS. 3A-3B are block diagrams of a sensor proximity detection and notification system, according to some embodiments.

FIG. 3C is a block diagram of an occupancy sensor system, according to some embodiments.

FIG 4 is a perspective view of a child vehicle seat detection and mobile notification system, according to some embodiments.

FIG 5 is a block diagram of an example child vehicle seat proximity detection system, according to some embodiments.

FIG 6 is a flowchart of a removable vehicle seat detection method, according to some embodiments.

FIG. 7 is a flowchart of a child vehicle seat occupancy detection method, according to some embodiments.

FIG 8 is a block diagram of a computer system to implement child vehicle seat detection system, according to some embodiments.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments that may be practiced.

These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be used and that structural, logical, and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.

The functions or algorithms described herein may be implemented in software or a combination of software and human implemented procedures in one embodiment. The software may consist of computer executable instructions stored on computer readable media such as memory or other type of storage devices. Further, such functions correspond to specifically programmed modules, which are software, hardware, firmware, or any combination thereof. Multiple functions may be performed in one or more modules as desired, and the embodiments described are merely examples. The software may be executed on a digital signal processor, ASIC, microprocessor, or other type of processor operating on a computer system, such as a personal computer, server, or other computer system.

Described herein are methods and systems for alerting a parent based on occupancy of a child vehicle seat. The child vehicle seat occupancy system may include an enclosure containing a hardware occupancy sensor circuit, a controller circuit, and a radio frequency (RF) communication circuit. In some embodiments, the transmitter communicates with a mobile electronic device, detects proximity to the device, and causes the mobile electronic device to generate an abandonment alert.

FIG 1 is a perspective view of a child vehicle seat occupancy detection and notification system 100, according to some embodiments. System 100 may include a child seat 1 10 and seat base 120. The base 120 may be installed in the vehicle and may remain in the vehicle. The child seat 110 securely fastens to the base 120, and the seat 1 10 may be removed from the vehicle without removing a child from the seat 1 10. In some examples, the child seat 1 10 may be removed from a vehicle and securely fastened to another base or to a stroller adapted to receive the seat 110. The seat 110 may include a magnetic element 130. Magnetic element 130 may be within the seat 1 10 as originally manufactured, or may be added to the seat 1 10 using adhesive, clips, or any attachment. Similarly, the base 120 may include a sensor device 140, where the sensor device 140 may be manufactured within the base 120 or may be attached to the base 120 using adhesive, clips, or any attachment.

When used in removable vehicle seats, such as those designed for children, the sensor device 140 may help determine if a child is within a vehicle. The sensor 140 may include a magnetic detection sensor, such as a Hall effect sensor that outputs a voltage in response to a magnetic field. The sensor 140 may generate a magnetic proximity distance to indicate an approximate distance between the magnet 130 and the sensor 140. The sensor 140 may generate a binary magnetic proximity signal to indicate whether the seat 1 10 is in sufficiently close proximity with the base 120, such as comparing a Hall effect sensor voltage against a minimum voltage threshold. In some examples, the seat 1 10 must be snapped into the base 120 before the sensor 140 provides a signal indicating the seat 1 10 is in sufficiently close proximity with the base

120. The magnetic proximity signal may be used to determine if the child seat 110 has been separated from the base 120, which may be used by system 100 to infer that a child in seat 1 10 is no longer within the vehicle. In one embodiment, the sensor 140 may include a magnetic reed switch that opens when the seat 1 10 is removed from the base 120.

Though this application discusses proximity detection using a magnet 130 and sensor 140, other proximity sensors may be used. For example, the proximity sensor may include a capacitive sensor, Doppler effect sensor, eddy-current sensor, inductive sensor, laser rangefinder sensor, magnetic sensor, optical sensor, thermal infrared sensor, photocell sensor, radar sensor, ionizing radiation reflection sensor, sonar sensor, ultrasonic sensor, fiber optics sensor, or another proximity sensor.

FIG 2A is a perspective view of a child vehicle seat detection and notification system 200, according to some embodiments. System 200 includes a child seat 210 and a mobile electronic device 220, such as a smartphone. The child seat may include a magnet 230 and a sensor 240, and the sensor 240 may generate a magnetic proximity signal to indicate that the magnet 230 is in close proximity with the sensor 240. The sensor 240 includes a processor 250 and an RF communication circuit 260. In various examples, the sensor 240, via the RF circuit 260, transmits magnetic proximity signals to the mobile electronic device 220, to a vehicle computer system, or to another device. The RF circuit may transmit signals in accordance with a low power wireless transmission standard, such as Bluetooth Low Energy (BTLE), IEEE 802.15.1, IEEE 802.15.4, or other standards. The RF circuit 260 may be paired with one or more of the mobile electronic device 220 or with a vehicle to establish such communications.

In some embodiments, the sensor 240 receives a raw magnetic sensor measurement, interprets the raw measurement as an estimated distance or binary magnetic proximity signal, formats the interpreted data, and transm its the formatted data. For example, a raw magnetic sensor measurement may include a voltage level received from a Hall effect sensor, and the voltage level may be compared against a voltage threshold to generate a binary magnetic proximity signal indicating that the seat 210 is securely fastened within the vehicle. In other embodiments, the sensor 240 receives and transmits the raw measurement to the device 220, and the device 220 interprets the raw measurement. In still other embodiments, the sensor 240 receives and interprets the raw measurement, and transmits both the raw measurement and the interpreted measurement to the device 220. The raw and interpreted measurements may be received by the processor 250 and converted into a data format that is compatible with the target device, such as using a data format compatible with an application running on the mobile device 220 or a data format compatible with a vehicle computer system.

The magnetic proximity signal may be received by device 220, and an application running on device 220 may indicate whether the magnet 230 is in close proximity with the sensor 240. The magnetic proximity signal may be used to determine if the seat 210 is completely secured. For example, the application on device 220 may receive a binary magnetic proximity signal and present a computer-generated image a seat securely snapped into a seat base. In an example, device 220 or a vehicle computer system may also determine an apparent vehicle speed, and may use the received magnetic proximity signals to provide a warning if the seat is not completely secured while traveling above a vehicle speed threshold. For example, device 220 may receive a nonzero vehicle speed and a binary magnetic proximity signal indicating seat 210 is unfastened, and may generate an audible alarm, a vibrating alarm, and a flashing display to warn the user that seat 210 is unfastened.

FIG. 2B is a perspective view of a child vehicle seat occupancy detection and notification system 270, according to some embodiments. System 270 includes a child seat 272 and a mobile electronic device 220, such as a smartphone. The child seat may include a sensor 274, and the sensor 274 may generate an occupancy signal to indicate that a child is in close proximity with the sensor 274. The sensor 274 includes a processor 276 and an RF communication circuit 278. In various examples, the sensor 274, via the RF circuit 278, transmits occupancy signals to the mobile electronic device 220, to a vehicle computer system, or to another device.

The RF circuit may transmit signals in accordance with a low power wireless transmission standard, such as Bluetooth Low Energy (BTLE), IEEE 802.15.1, IEEE 802.15.4, or other standards. The RF circuit 278 may be paired with one or more of the mobile electronic device 220 or with a vehicle to establish such communications.

In some embodiments, the sensor 274 receives a raw occupancy sensor measurement, interprets the raw measurement as an estimated distance or binary occupancy signal, formats the interpreted data, and transmits the formatted data.

For example, a raw occupancy sensor measurement may include a voltage level received from an inductive wire loop sensor, and the voltage level may be compared against a voltage threshold to generate a binary occupancy signal indicating that the seat 272 is occupied. In other embodiments, the sensor 274 receives and transmits the raw measurement to the device 220, and the device 220 interprets the raw measurement. In still other embodiments, the sensor 274 receives and interprets the raw measurement, and transmits both the raw measurement and the interpreted measurement to the device 220. The raw and interpreted measurements may be received by the processor 276 and converted into a data format that is compatible with the target device, such as using a data format compatible with an application running on the mobile device 220 or a data format compatible with a vehicle computer system.

The occupancy signal may be received by device 220, and an application running on device

220 may indicate whether the child is in close proximity with the sensor 274. The occupancy signal may be used to display whether the seat 272 is occupied. For example, the application on device 220 may receive a binary occupancy signal and present a computer-generated image of a child within a child vehicle seat.

FIGS. 3A-3B are block diagrams of a sensor proximity detection and notification system 300, according to some embodiments. System 300 includes sensor 304 and device 308, where sensor 304 and device 308 may include proximity detection circuitry. FIG 3A illustrates sensor 304 and device 308, where the proximity detection circuitry determines that the sensor 304 and the device 308 are separated by a distance of 1-2 feet. FIG 3B illustrates sensor 304 and device 308, where the proximity detection circuitry determines that the sensor 304 and the device 308 are separated by a distance of 30- 50 feet. Other distances may be used, and the distance may be extended in some embodiments using an RF power amplifier.

In some examples, the proximity detection circuitry includes an RF proximity sensor, and the RF proximity sensor may generate an RF proximity signal. The RF proximity sensor may generate the RF proximity signal based on a detected signal power, a received signal strength indicator (RSSI), or other RF signal characteristics. In some examples, presence or absence of an RF signal may be used alone or in combination with the RF proximity sensor to determine a binary RF proximity signal. In some examples, location information may be used to determine an RF proximity, such as using GPS information, cellular tower triangulation, Wi-Fi access point triangulation, or other location information. For example, a sensor GPS location may be provided by the vehicle in which the sensor 304 is installed, a device GPS location may be determined by device 308, and the location differences may be used to generate or improve accuracy of the RF proximity signal. In some examples, multiple radio or location sources may be combined to generate or improve distance determinations. The RF proximity signal may include a binary RF proximity signal to indicate whether the sensor 304 is in sufficiently close proximity with the device 308. For example, if the RSSI value falls below an RSSI threshold or if the signal power falls below a signal power threshold, a binary RF proximity signal may be generated to indicate that the device 308 has abandoned (e.g., gone out of range of) the sensor 304. The RF proximity signal may include an approximate distance between the sensor 304 and the device 308. The approximate distance may be grouped into two or more ranges, such as the 1-2 foot range shown in FIG 3 A or the 30-50 foot range shown in FIG 3B, and an RF proximity alert (e.g., alarm) may be generated when there is a transition from a first range to a second range. The approximate distance may be monitored continually for a range trend. For example, successive range measurements may indicate that the distance between device 308 and sensor 304 is increasing, which may indicate that the device 308 is moving away from the sensor 304, and a binary RF proximity signal may be generated to indicate that the device 308 has abandoned the sensor 304.

An RF proximity alert (e.g., alarm) may be generated to notify a user. The alert may include a visible alert, an audible alert, a tactile alert (e.g., vibration), a text or e-mail message, or other alert. In some examples, the device 320 may include a mobile device processor, where the processor is executing foreground or background software to generate a visible or audible alarm, and the device 320 may include speakers or other hardware or circuitry to generate the alarm. In some examples, the sensor 310 may generate an alarm either using internal alarm circuitry or by sending the alert to a vehicle alarm system. One or more alarms may be used in combination to increase the probability that a user is notified.

In some embodiments, the RF proximity detection circuitry operates unidirectionally, such as sensor 304 detecting an RF signal from device 308 and determining an RF proximity. This unidirectional operation may enable a proximity detection system where only a single proximity detection circuit is required. For example, the proximity detection circuit may be packaged and sold within the sensor 304, and it may operate with any device 308 that emits an RF signal that can be detected by the proximity detection circuit on the sensor 304. A unidirectional system may be used to generate a single alert on the device housing the proximity detection circuit, or may be used to generate and send a proximity alert from the proximity detection circuit device to another device. For example, when a range of 30-50 feet is detected by the sensor 304, the sensor 304 may send an alert to the device 308.

In other embodiments, the proximity detection circuitry operates bidirectionally, and sensor 304 and device 308 may receive RF signals from each other and independently determine RF proximities. This bidirectional operation may enable independent detection of proximity or independent generation of proximity alerts.

FIG. 3C is a block diagram of an occupancy sensor system 309, according to some embodiments. System 309 may be implemented using a mobile device processor, a dedicated integrated circuit (IC), or other circuit components. System 309 may include an occupancy sensor

310. The occupancy sensor 310 may indicate a change in proximity, where the indication is in the form of a change in an electrical characteristic. For example, the occupancy sensor 310 may provide a change in voltage, capacitance, inductance, or other electrical characteristic. The occupancy sensor 310 may include a complex sensor such as a dedicated proximity sensing integrated circuit, or may include a simple sensor such as a wire loop 315. The use of a wire loop or other simple sensor may reduce manufacturing complexity and improve reliability. For example, a wire loop 315 may be electrically connected to or integrated within a switched capacitor circuit in occupancy sensor 310. A baseline capacitance may be measured using the wire loop 315, where the baseline capacitance includes the parasitic capacitance of the wire loop 315, surrounding electronics, the child vehicle seat structure, and other nearby structures. When a child is placed in the child vehicle seat in proximity to the wire loop 315, the child and wire loop 315 combine to form a parallel plate capacitor with associated capacitance, and the capacitance measured at the occupancy sensor 310 includes the sum of the parasitic capacitance and the parallel plate capacitance. The capacitance changes may be detected using various techniques, such as using the analog to digital converter 320 described below.

System 309 may include an analog to digital converter (ADC) 320. The ADC 320 may convert a signal from the occupancy sensor 310 into one or more voltage levels indicative of a change in occupancy or proximity. To detect seat occupancy, a current source may be used to generate a linear voltage ramp on the capacitor within the occupancy sensor 310, and the voltage output may be fed into the ADC 320. The ADC 320 may include a comparator and a counter, where the counter increments whenever the comparator output transitions from high to low. The counter output of the ADC 320 may be tracked over time. A lower frequency of counts may be associated with a baseline occupancy counter frequency that indicates an unoccupied child seat. Conversely, a higher frequency of counts may be associated with an occupied child seat. The count frequencies associated with the unoccupied and occupied child seat may be static or variable values, any may be adjusted (e.g., tuned) manually or automatically to ensure detection of an occupied child seat.

The ADC 320 may include a delta-sigma modulator, a filter, or other components. For example, the ADC 320 may perform delta modulation to encode the change in signal over time, integrate the modulated signal, sample the integrated signal, filter the sampled signal, and decimate the filtered signal. Though system 309 is described using an ADC 320, other capacitive and non-capacitive sensing methods may be used. In addition or alternative to the ADC, system 309 may use one or more other capacitive sensing methods. In some embodiments, the wire loop capacitance value may be converted into a resistance value, and a voltage may be applied to the resistance value to monitor changes in loop capacitance. The voltage may have an associated static value, may have an associated periodic waveform, or may be a shaped waveform input. In an example, the change in capacitance may be detected through charge transfer, where the change in capacitance due to the child modifies the charge transfer between a sensor capacitor and reference capacitor, where incremental charge packets are transferred until reaching a predetermined occupancy threshold voltage on the reference capacitor. In another example, a sensor capacitor is used to detect a child by detecting a change in frequency of an oscillator by detecting an increase in sensor capacitance or decrease in oscillator frequency. In another example, a source waveform is driven as an input, and the occupancy is detected by the change in capacitance and the associated change to the waveform output. Various methods may be used in the alternative or in combination.

The system may include a microprocessor 330. The microprocessor 330 may receive digital signals from the ADC 320 representative of various occupancy measurements. The microprocessor 330 may also receive information from other external sensors, such as a temperature sensor 340, an impact sensor 350, a Bluetooth radio 360, or from other sensors. The microprocessor 330 may receive RF proximity signals from Bluetooth radio 360 via a Bluetooth antenna 365, where the RF proximity signals indicate RF proximity between the Bluetooth radio

360 and an external mobile electronic device. The microprocessor 330 may also use the Bluetooth radio 360 to communicate with the external mobile electronic device, including sending or receiving alerts or occupancy or proximity information. Components of the occupancy sensor system 309 may be implemented on two or more devices. In an example, a child vehicle seat may be manufactured to include occupancy sensor 310, ADC 320, microprocessor 330, temperature sensor 340, impact sensor 350, and Bluetooth radio 360. In other embodiments, some or all of the system components may be implemented in a mobile electronic device, in a vehicle, or in another device.

The microprocessor 330 may generate an alert based on signals received from any one sensor. For example, the microprocessor 330 may receive a signal from the ADC 320, compare the signal to a threshold, and provide an alert based on whether the seat is occupied. The microprocessor 330 may generate an alert based on a combination of signals received from multiple sensors. For example, the microprocessor 330 may determine a seat is occupied based on a received signal from the ADC 320, determine that a parent's Bluetooth device has moved beyond a threshold based on a received signal strength indicator (RSSI) from the Bluetooth radio 360, and generate an alert that indicates the seat is occupied and unsupervised.

In another example, an alert may be generated if the seat is occupied and the temperature sensor 340 indicates the temperature exceeds a threshold, or if the seat is occupied and the impact sensor 350 indicates that the vehicle has been involved in a collision.

The microprocessor 330 may generate a conventional alert that is sent to a mobile device.

Because some alerts are based on the mobile device proximity exceeding a threshold, the proximity threshold may be configured such that the alert is generated and sent before the device is out of range of the Bluetooth radio 360. Additional radios may be used to convey an alert. For example, an alert may be generated when the seat is occupied and the mobile device is out of range of the Bluetooth radio 360, where the alert is transmitted to the mobile device via Wi-Fi, cellular data, or another radio signal. In addition to the conventional alert sent to the mobile device, the microprocessor 330 may also generate an alert suppression signal that causes the mobile device to alert the user whenever the suppression signal is lost. For example, the mobile device may detect an occupied seat and send an alert suppression signal to the mobile device, and the mobile device may generate an alert when the mobile device is out of range of the alert suppression signal. The conventional alert signal and suppression signal may be used in the alternative or in combination to ensure the user is alerted.

FIG 4 is a perspective view of a child vehicle seat detection and mobile notification system 400, according to some embodiments. System 400 includes a vehicle 410, where vehicle 410 may include the seat 110, base 120, magnet 130, and sensor 140 shown in FIG 1. A magnetic proximity signal may be transmitted from vehicle 410 to a mobile electronic device, where the magnetic proximity signal indicates that a removable vehicle seat is within vehicle 410. The magnetic proximity signal may be received by the mobile electronic device at a first device location 420. The first device location 420 may be in close proximity to the vehicle, such as when a user first exits a vehicle. The magnetic proximity signal may also be received by the mobile electronic device at a second location 430, where the second Jocation 430 is further from the vehicle 410 than the first location 420. If the device moves to a second location 430 while the magnetic proximity signal indicates the seat within the car, then an abandonment alert may be generated. In addition to the abandonment alert, system 400 may also alert a user of various combinations of proximities. For example, a minor vibration warning may be generated when a user first exits a vehicle, and a substantial abandonment alert may be generated if the user moves away from the vehicle while the child seat is attached to the base.

System 400 may use various vehicle features. A vehicle alarm system may be used to notify the user, such as honking the horn or flashing lights to indicate an abandonment alert. A vehicle equipped with a roadside emergency service system may contact the service to request help or to initiate a phone call with an operator to determine if a child is within the vehicle. A vehicle may also provide an indication of vehicle speed or movement, and system 400 may enter a reduced power (e.g., sleep) mode when the vehicle is moving. A vehicle may provide an environmental response to an abandonment alert, such as opening car windows or turning on air conditioning. A vehicle may also provide an environmental input, such as temperature, humidity, or other environmental measurement, such as the environmental sensors shown in FIG. 5.

FIG. 5 is a block diagram of a child vehicle seat proximity detection system 500, according to some embodiments. The system includes detection circuitry 510, where detection circuitry 510 may be a mobile device processor, a dedicated integrated circuit (IC), or other circuit. The detection circuitry 510 may receive magnetic proximity signals from a magnetic sensor 520, where the magnetic proximity signals indicate a magnetic proximity between the magnetic sensor 520 and a magnet 530.

The detection circuitry 510 may receive RF proximity signals from RF circuitry 540, where the RF proximity signals indicate RF proximity between the RF proximity sensor 540 and an external mobile electronic device. The detection circuitry 510 may also use the RF circuitry 540 to communicate with the external mobile electronic device, including sending or receiving alerts or proximity information.

The detection circuitry 510 may also receive various other inputs, such as an input from a temperature sensor 550 or from a humidity sensor 560. The detection circuitry 510 may combine inputs from various sensors to generate various alerts. For example, detection circuitry 510 may use a magnetic sensor 520 input to determine that a removable vehicle seat is within a vehicle, and may warn a user when the temperature sensor 550 and humidity sensor 560 indicate an unsafe environment within a vehicle.

Components of the child vehicle seat proximity detection system 500 may be implemented on two or more devices. In an example, a removable vehicle seat may be manufactured to include magnet 530, and a removable vehicle seat base may be manufactured to include the detection circuitry 510, magnetic sensor 520, RF circuitry 540, temperature sensor 550, and humidity sensor 560. In other embodiments, the RF circuitry 540, temperature sensor 550, or humidity sensor 560 may be implemented in a mobile electronic device, in a vehicle, or in another device.

FIG 6 is a flowchart of a removable vehicle seat detection method 600, according to some embodiments. Method 600 may be executed on a device processor that has been specifically programmed or designed to carry out method steps. Method 600 includes generating 610 a magnetic proximity signal. The magnetic proximity signal may include a voltage level generated by a Hall Effect sensor. The magnetic proximity signal is representative of a magnetic proximity between a magnetic sensor attached to a base and a magnet attached to a removable object. The removable object may be attached to and removed from the base, such as a removable vehicle seat. Based on the magnetic proximity signal, method 600 includes determining 620 that the removable object is attached to the base.

Method 600 includes generating 630 an RF proximity indication representative of a device distance between an RF circuit and a mobile electronic device. The RF proximity indication may be based on a detected signal power, a received signal strength indicator (RSSI), presence or absence of an RF signal, or other RF signal characteristics. In some examples, location information may be used to determine an RF proximity, such as using GPS information, cellular tower triangulation, Wi-Fi access point triangulation, or other location information. The RF proximity indication may be generated by an RF circuit. The RF circuit may be configured to communicate based on a wireless communication standard, wherein the wireless communication standard is based on at least one of a BTLE standard, an IEEE 802.15.1 standard, and an IEEE 802.15.4 standard. Based on the RF proximity indication, method 600 includes determining 640 that the device distance exceeds a maximum device distance threshold. Based on a combination of determining 620 that the removable object is attached to the base and determining 640 that the device distance exceeds a maximum device distance threshold, method 600 may generate 650 an abandonment alert.

Method 600 may include determining 660 that an environmental measurement exceeds a maximum environmental measurement safety threshold. The environmental measurement may be received by an environmental sensor. In some examples, the environmental measurement is at least one of a humidity measurement and a temperature measurement. Based on a combination of determining 620 that the removable object is attached to the base and determining 660 that an environmental measurement exceeds a maximum environmental measurement safety threshold, method 600 may generate 670 an environment alert.

Method 600 includes transmitting 680 an alert, where the alert may include at least one of the abandonment alert and the environment alert. The alert may be transmitted via an RF circuit to a mobile electronic device such as a smartphone, to a vehicle, or to another electronic device. Method 600 includes notifying 690 a user of the alert. In some examples, notifying 690 includes causing a mobile electronic device to flash, vibrate, play a sound, display a warning message, send a text or e- mail message, and other forms of notification. In some examples, notifying 690 includes causing a vehicle alarm system to honk a horn, flash vehicle lights, or provide other vehicular notification. Various forms of notification may be combined to increase the probability that a user is notified. FIG. 7 is a flowchart of a child vehicle seat occupancy detection method 700, according to some embodiments. Method 700 may be executed on a device processor that has been specifically programmed or designed to carry out method steps. Method 700 may include determining baseline occupancy signal characteristics 710. The occupancy signal may include a voltage level generated by an occupancy sensor. The baseline occupancy characteristics may include a voltage that corresponds to an unoccupied child vehicle seat. Determining the baseline occupancy signal characteristics 710 may occur when the child vehicle seat is manufactured, when the child vehicle seat is first used, or each time a child is removed from the child vehicle seat. A single baseline voltage may be stored for later comparison, or multiple historic baseline voltages may be stored for analysis, calibration, or troubleshooting purposes.

Method 700 may include determining occupancy via capacitive sensing 720. Determining occupancy via capacitive sensing 720 may be based on the baseline occupancy signal characteristics. For example, the baseline signal may be compared to a new occupancy capacitive sensing voltage, and a change in capacitive sensing voltage that exceeds a threshold may be used to detect or indicate occupancy of the seat. The determination of occupancy may be with respect to absolute sensor values. For example, voltage levels for an unoccupied seat and for an occupied seat may be set to specific values, and those values may be used for occupancy detection. The determination of occupancy may be with respect to relative or variable sensor values. Voltage levels for an unoccupied seat and for an occupied seat may be determined each time a child is placed into the seat. For example, when a voltage change of at least one volt is detected, then the voltage level before the change is associated with an unoccupied seat state and the voltage level after the change is associated with an occupied seat state. This dynamic update would allow the system to compensate for capacitive or voltage level fluctuations due to clothing, humidity, temperature, or other external factors. A hysteresis may be used to improve occupancy detection or reduce false alarms. For example, if three volts corresponds to an unoccupied seat and five volts corresponds to an occupied seat, then the seat state may not transition from occupied to unoccupied until the voltage level drops below four volts. The voltage values may be static, variable, user-configurable, or otherwise adjustable. Though various embodiments are described herein with respect to capacitive sensing, other occupancy sensor technologies may be used.

Method 700 includes determining that a mobile device distance exceeds a threshold 730. After determining that a seat is occupied, a mobile electronic device proximity may be monitored to determine if the mobile electronic device has moved beyond an abandonment threshold while the child vehicle seat is occupied. The mobile electronic device proximity may be based on a detected signal power, a received signal strength indicator (RSSI), lost connection detection, presence or absence of an RF signal, or other RF signal characteristics. In some examples, location information may be used to determine an RF proximity, such as using GPS information, cellular tower triangulation, Wi-Fi access point triangulation, or other location information. The proximity indication may be generated by an RF circuit. The RF circuit may be configured to communicate based on a wireless communication standard, wherein the wireless communication standard is based on at least one of a BTLE standard, an IEEE 802.15.1 standard, and an IEEE 802.15.425 standard. Based on a combination of determining occupancy via capacitive sensing 720 and determining that a mobile device distance exceeds a threshold 730, method 7 00 may generate 740 an abandonment alert.

Method 700 may include determining that an environmental measurement exceeds a maximum environmental measurement safety threshold 750. The environmental measurement may be received by an environmental sensor, an impact sensor, or other sensor. Based on a combination of determining occupancy via capacitive sensing 720 and determining that an environmental measurement exceeds a maximum environmental measurement safety threshold 750, method 700 may generate 760 an environment alert.

Method 700 includes notifying the user of an alert 770. An alert may be generated and a user notified when the seat is occupied and the mobile device is out of range. As described above, a conventional alert signal or an alert suppression signal may be generated, where the mobile device may generate an alert when the mobile device is out of range of the alert suppression signal. The alert may be transmitted via an RF circuit to a mobile electronic device such as a smartphone, to a vehicle, or to another electronic device. In some examples, notifying 770 includes causing a mobile electronic device to flash, vibrate, play a sound, display a warning message, send a text or e-mail message, and other forms of notification. In some examples, notifying 770 includes causing a vehicle alarm system to honk a horn, flash vehicle lights, or provide other vehicular notification. Various forms of notification may be combined to increase the probability that a user is notified.

In some embodiments, one or more operations of method 700 may be performed by a mobile device , which may receive occupancy information from a system, such as system 309 (FIG. 3C) via one or more wireless connections, such as via Bluetooth radio 360. The application running on the mobile device may use the occupancy information and signal strength to trigger an alert, or may use an indication of a lost Bluetooth connection to trigger an alert.

FIG 8 is a block schematic diagram of a computer system 800 to implement child vehicle seat detection system, according to some embodiments. The computer system 800 may use fewer components than shown in FIG. 8 in some embodiments to perform the methods described. One example computing device in the form of a computer 800, may include a processing unit 802, memory 803, removable storage 810, and non-removable storage 812. Memory 803 may include volatile memory 814 and non- volatile memory 808. Computer 800 may include - or have access to a computing environment that includes- a variety of computer-readable media, such as volatile memory 814 and non-volatile memory 808, removable storage 810 and non-removable storage 812. Computer storage includes random access memory (RAM), read only memory (ROM), erasable programmable read-only memory (EPROM) & electrically erasable programmable readonly memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD ROM), Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium capable of storing computer-readable instructions. Computer 800 may include or have access to a computing environment that includes input 806, output 804, and a communication connection 816. The computer may operate in a networked environment using a communication connection to connect to one or more remote computers, such as database servers. The remote computer may include a personal computer (PC), server, router, network PC, a peer device or other common network node, or the like. The communication connection may include a Local Area Network (LAN), a Wide Area Network (WAN) or other networks.

Computer-readable instructions stored on a computer-readable medium are executable by the processing unit 802 of the computer 800. A hard drive, CD-ROM, and RAM are some examples of articles including a non-transitory computer-readable medium. For example, a computer program 818 capable of providing a generic technique to perform access control check for data access and/or for doing an operation on one of the servers in a component object model (COM) based system may be included on a CD-ROM and loaded from the CD-ROM to a hard drive. The computer-readable instructions allow computer 800 to provide generic access controls in a COM based computer network system having multiple users and servers.

The present disclosure supports several examples, including but not limited to the following:

Example 1 includes a removable object proximity detection system, the system comprising a magnet attached to a removable object, a magnetic sensor attached to a base, the magnetic sensor configured to generate a magnetic proximity signal representative of a magnetic proximity between the removable object and the base, the removable object configured to be removably attached to the base, a radio frequency (RF) circuit, the RF circuit configured to communicate with a mobile electronic device and to generate an RF proximity indication, the RF proximity indication representative of a device distance between the RF circuit and the mobile electronic device, and a device processor electrically coupled to the magnetic sensor and to the RF circuit, the device processor specifically programmed to receive the magnetic proximity signal from the magnetic sensor, determine, based on the magnetic proximity signal, that the removable object is attached to the base, receive the RF proximity indication from the RF circuit, determine, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold, and generate an abandonment alert, the alert indicating that the removable object is attached to the base and that the device distance exceeds the maximum device distance threshold.

Example 2 includes the system of example 1, wherein the device processor is further specifically programmed to transmit the abandonment alert to the mobile electronic device via the RF circuit.

Example 3 includes the system of example 1, further including an audible alert circuit, wherein the device processor is further specifically programmed to cause the audible alert circuit to generate an audible alert. Example 4 includes the system of example 1, wherein the device processor is further specifically programmed to transmit the abandonment alert to a vehicle alarm system to generate a vehicle alarm.

Example 5 includes the system of example 1, wherein the RF proximity indication includes a received signal strength indicator (RSSI).

Example 6 includes the system of example 1 , further including an environmental sensor, wherein the environmental sensor generates an environmental measurement representative of an environmental condition, and the device processor is further specifically programmed to receive the environmental measurement, determine that the environmental measurement exceeds a maximum environmental measurement safety threshold, and generate an environment alert, the alert indicating that the removable object is attached to the base and that the environmental condition is unsafe.

Example 7 includes the system of any of examples 1 -6, wherein the environmental measurement is at least one of a humidity measurement and a temperature measurement.

Example 8 includes the system of example 1, wherein the RF circuit is further configured to communicate based on a wireless communication standard.

Example 9 includes the system of any of examples 1-8, wherein the wireless communication standard is based on at least one of a BTLE standard, an IEEE 802.15.1 standard, and an IEEE 802.15.4 standard.

Example 10 includes the system of example 1 , wherein the magnetic sensor includes a Hall Effect sensor.

Example 1 1 includes the system of example 1, wherein the device processor is a microcontroller.

Example 12 includes a magnetic proximity detection system, the system comprising a mobile electronic device RF circuit, the RF circuit configured to communicate with a magnetic sensor and to generate an RF proximity indication, the RF proximity indication representative of a device distance between the RF circuit and the magnetic sensor, a mobile electronic device processor electrically coupled to the RF circuit, the mobile electronic device configured to execute software specifically programmed to receive a magnetic proximity signal from the magnetic sensor, the magnetic proximity signal representative of a magnetic proximity between a magnet and the magnetic sensor, determine, based on the magnetic proximity signal, that the magnet is in close proximity to the magnetic sensor, receive the RF proximity indication from the RF circuit, determine, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold, and generate an abandonment alert, the alert indicating that the magnet is in close proximity to the magnetic sensor and that the device distance exceeds the maximum device distance threshold.

Example 13 includes the system of example 12, further including an audible signal generation circuit, wherein the mobile electronic device processor software is further specifically programmed to cause the audible signal generation circuit to generate an audible alert.

Example 14 includes the system of example 12, wherein the mobile electronic device processor software is further specifically programmed to transmit the abandonment alert to a vehicle alarm system to generate a vehicle alarm.

Example 15 includes the system of example 12, wherein the RF proximity indication includes a received signal strength indicator (RSSI).

Example 16 includes the system of example 12, wherein the mobile electronic device software is further specifically programmed to receive an environmental measurement representative of an environmental condition, determine that the environmental measurement exceeds a maximum environmental measurement safety threshold, and generate an environment alert, the alert indicating that the magnet is in close proximity to the magnetic sensor and that the environmental condition is unsafe. Example 17 includes the system of any of examples 12-16, wherein the environmental measurement is at least one of a humidity measurement and a temperature measurement.

Example 18 includes the system of example 12, wherein the RF circuit is further configured to communicate based on a wireless communication standard.

Example 19 includes the system of any of examples 12-18, wherein the wireless communication standard is based on at least one of a BTLE standard, an IEEE 802.15.1 standard, and an IEEE 802.15.4 standard.

Example 20 includes the system of example 12, wherein the magnetic sensor includes a Hall Effect sensor.

Example 21 includes a method for removable object proximity detection executing on a specifically programmed device processor, the method including generating a magnetic proximity signal representative of a magnetic proximity between a magnetic sensor attached to a base and a magnet attached to a removable object, the removable object configured to be removably attached to the base, determining, based on the magnetic proximity signal, that the removable object is attached to the base, generating an RF proximity indication representative of a device distance between an RF circuit and a mobile electronic device, determining, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold, and generating an abandonment alert, the alert indicating that the removable object is attached to the base and that the device distance exceeds the maximum device distance threshold.

Example 22 includes the method of example 21, further including transmitting the abandonment alert to the mobile electronic device via the RF circuit.

Example 23 includes the method of example 21, further including generating an audible alert via an audible alert circuit. Example 24 includes the method of example 21 , further including transmitting the abandonment alert to a vehicle alarm system to generate a vehicle alarm.

Example 25 includes the method of example 21, wherein the RF proximity indication includes a received signal strength indicator (RSSI).

Example 26 includes the method of example 21, further including generating an environmental measurement representative of an environmental condition via an environmental sensor, determining that the environmental measurement exceeds a maximum environmental measurement safety threshold, and generating an environment alert, the alert indicating that the removable object is attached to the base and that the environmental condition is unsafe.

Example 27 includes the method of any of examples 21-27, wherein the environmental measurement is at least one of a humidity measurement and a temperature measurement.

Example 28 includes the method of example 21, wherein the RF circuit is configured to communicate based on a wireless communication standard.

Example 29 includes the method of any of examples 21-29, wherein the wireless communication standard is based on at least one of a BTLE standard, an IEEE 802.15.1 standard, and an IEEE 802.15.4 standard.

Example 30 includes the method of example 21, wherein the magnetic sensor includes a Hall Effect sensor.

Example 31 includes a removable object proximity detection system, the system comprising a magnet attached to a removable object, a magnetic sensor attached to a base, the magnetic sensor configured to provide an attachment signal representative of an attachment of the removable object to the base, a radio frequency (RF) circuit, the RF circuit configured to communicate with a mobile electronic device and to generate an RF proximity indication, the RF proximity indication representative of a device distance between the RF circuit and the mobile electronic device.

Example 32 includes the system of example 31, further including a device processor electrically coupled to the magnetic sensor, the device processor specifically programmed to receive the attachment signal from the magnetic sensor, determine, based on the attachment signal, that the removable object is attached to the base, receive the RF proximity indication from the RF circuit, determine, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold, and generate an abandonment alert, the alert indicating that the removable object is attached to the base and that the device distance exceeds the maximum device distance threshold.

Example 33 includes the system of example 31 wherein the RF circuit receives the attachment signal and transmits the signal including the RF proximity indication and the attachment signal to a paired device.

Example 34 includes the system of any of examples 31-33, further including a user notification circuit, wherein the user notification circuit is configured to receive the abandonment alert and notify a user of the abandonment alert.

Example 35 includes the system of any of examples 31-35, wherein notifying a user of the abandonment alert includes notifying a user by at least one of sending a text message, sending an e- mail message, flashing a light, generating a vibration, playing a sound, and displaying a warning message.

Example 36 includes the system of example 31, wherein generating the RF proximity indication includes generating an approximate RF distance based on a received signal strength indicator (RSSI).

Example 37 includes the system of example 31, further including an environmental sensor, wherein the environmental sensor generates an environmental measurement representative of an environmental condition, and the device processor is further specifically programmed to receive the environmental measurement, determine that the environmental measurement exceeds a maximum environmental measurement safety threshold, and generate an environment alert, the alert indicating that the removable object is attached to the base and that the environmental condition is unsafe.

Example 38 includes the system of any of examples 31-38, wherein the environmental measurement is at least one of a humidity measurement and a temperature measurement.

Example 39 is a child seat occupancy detection system, the system comprising a child seat occupancy detection sensor; a radio frequency (RF) circuit, the RF circuit configured to communicate with a mobile electronic device; and a device processor electrically coupled to the occupancy sensor and to the RF circuit, the device processor specifically programmed to: receive a baseline occupancy signal from the occupancy sensor, the baseline occupancy signal representative of an empty child seat; receive an operational occupancy signal from the occupancy sensor; determine that a difference between the baseline occupancy signal and the operational occupancy signal exceeds an occupancy signal threshold, the occupancy signal threshold representative of an occupied seat; receive an RF proximity indication from the RF circuit, the RF proximity indication representative of a device distance between the RF circuit and the mobile electronic device; determine, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold; and generate an abandonment alert, the alert indicating that the child seat is occupied and that the device distance exceeds the maximum device distance threshold.

In Example 40, the subject matter of Example 1 optionally further includes wherein the child seat occupancy detection sensor includes a capacitive occupancy sensor, the capacitive sensor configured to be sensitive to a human proximity.

In Example 41 , the subject matter of any one or more of Examples 39^10 optionally further includes wherein the capacitive occupancy sensor includes a wire loop.

In Example 42, the subject matter of any one or more of Examples 39-41 optionally further includes wherein the capacitive occupancy sensor is integrated into a child vehicle seat.

In Example 43, the subject matter of any one or more of Examples 39-42 optionally further includes wherein the capacitive occupancy sensor is integrated into a padding of the child vehicle seat.

In Example 44, the subject matter of any one or more of Examples 39-43 optionally further includes wherein the capacitive occupancy sensor is integrated into a molding of the child vehicle seat.

Example 45 is a method for child seat occupancy detection, the method comprising receiving a baseline occupancy signal from a child seat occupancy detection sensor, the baseline occupancy signal representative of an empty child seat; receiving an operational occupancy signal from the occupancy sensor; determining that a difference between the baseline occupancy signal and the operational occupancy signal exceeds an occupancy signal threshold, the occupancy signal threshold representative of an occupied seat; receiving an RF proximity indication from a radio frequency (RF) circuit, the RF proximity indication representative of a device distance between the RF circuit and a mobile electronic device; determining, based on the RF proximity indication, that the device distance exceeds a maximum device distance threshold; and generating an abandonment alert, the alert indicating that the child seat is occupied and that the device distance exceeds the maximum device distance threshold.

In Example 46, the subject matter of Example 45 optionally further includes determining the occupancy signal threshold based on a comparison between the baseline occupancy signal and the operational occupancy signal. In Example 47, the subject matter of any one or more of Examples 45-46 optionally further includes sending the abandonment alert to the mobile electronic device.

In Example 48, the subject matter of any one or more of Examples 45—47 optionally further includes sending the abandonment alert to a vehicle alarm system.

In Example 49, the subject matter of any one or more of Examples 45—48 optionally further includes wherein receiving the operational occupancy signal includes receiving a capacitive signal from a capacitive occupancy sensor within the child seat occupancy detection sensor, the capacitive sensor configured to be sensitive to a human proximity.

In Example 50, the subject matter of any one or more of Examples 45—49 optionally further includes wherein the capacitive occupancy sensor includes a wire loop.

In Example 51 , the subject matter of any one or more of Examples 45-50 optionally further includes wherein the capacitive occupancy sensor is integrated into a child vehicle seat.

In Example 52, the subject matter of any one or more of Examples 45-51 optionally further includes wherein the capacitive occupancy sensor is integrated into a padding of the child vehicle seat.

In Example 53, the subject matter of any one or more of Examples 45-52 optionally further includes wherein the capacitive occupancy sensor is integrated into a molding of the child vehicle seat.

Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Other embodiments may be within the scope of the following claims.