Patent Publication Number: US-9847004-B1

Title: Vehicle child detection and response system

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a passenger detection system for use in a vehicle and, more particularly, to a system that automatically detects a child left unattended in a vehicle and performs a suitable response when an unattended child is detected. 
     BACKGROUND OF THE INVENTION 
     In general, there is a lack of awareness as to how quickly the temperature can rise in a closed vehicle, or even in a vehicle in which the windows have been left slightly ajar. For example, on a day with an ambient temperature of 84° F., the temperature within the passenger cabin of a car can reach 104° F. in just 10 minutes. Even at a relatively cool outside temperature of 74° F., a vehicle&#39;s interior temperature can reach 104° F. in 20 minutes. As a result of these temperatures, a child or a pet left in an unattended vehicle for even a short period of time can suffer from heat stroke related symptoms, and in those cases in which relief is not provided immediately, the child or pet is likely to die from heat stroke. In the United States, heat stroke is the third most common non-traffic, motor-vehicle-related fatality scenario for children 14 and younger, on average accounting for 37 fatalities every year. Of these fatalities, 53.9% of the children were “forgotten” by caregivers, 28.6% of the children were playing in an unattended vehicle, and 16.8% of the children were intentionally left in a vehicle by an adult. Additionally, it is estimated that hundreds of pets die each year from heat stroke when left unattended in a car. 
     To combat this problem, communities and governmental agencies have implemented a variety of outreach programs. The intent of these programs is to educate the public as to the dangers of leaving a child or a pet unattended in a vehicle for even a short period of time. While these public awareness programs have proven helpful, the significant number of both child and pet fatalities that continue to occur demonstrate the need for additional remedies, in particular remedies that can be used to reliably detect the presence of a child, or pet, left unattended in a parked car and then take appropriate action when such a situation is detected. The present invention provides a solution to this problem, both in terms of a detection system and a methodology. 
     SUMMARY OF THE INVENTION 
     The present invention provides a child/pet detection system that is incorporated into a vehicle, the system comprising (i) a radar sensor mounted within the vehicle&#39;s passenger cabin (e.g., to the cabin&#39;s headliner) that is configured to detect motion within the passenger cabin; (ii) a monitoring system that outputs a first control signal when the driver exits the passenger cabin and a second control signal when the driver re-enters the passenger cabin; (iii) an alert system configured to output an alert, where the alert utilizes an alert mode selected from a plurality of alert modes; and (iv) a control system coupled to the radar sensor, the monitoring system and the alert system, the control system configured to (a) activate the radar sensor when the control system receives the first control signal, (b) monitor the radar sensor for a preset period of time (e.g., less than 30 minutes) after receipt of the first control signal, (c) activate the alert system when the radar sensor detects motion within the passenger cabin during the preset period of time, (d) select the alert mode, (e) alternate the selected alert mode over time, and (f) deactivate the alert system upon receipt of the second control signal. 
     In one aspect of the invention, the system may further include a heating, ventilation and air conditioning (HVAC) system that is coupled to the control system. The control system may be configured to activate the HVAC system after the radar sensor detects motion within the passenger cabin during the preset time. 
     In another aspect of the invention, a timer may be coupled to the control system, wherein the control system alternates the selected alert mode based on the elapsed time since alert system activation. A HVAC system may be coupled to the control system and the control system may be configured to activate the HVAC system after the elapsed time exceeds a preselected time period. 
     In another aspect of the invention, an in-cabin temperature sensor may be coupled to the control system, wherein the control system alternates the selected alert mode based on the monitored in-cabin temperature. A HVAC system may be coupled to the control system and the control system may be configured to activate the HVAC system after the monitored in-cabin temperature exceeds a preset temperature. 
     In another aspect of the invention, the control system may be configured to place the radar sensor into a standby mode if it does not detect motion during the preset period of time. In standby mode, the radar sensor may be deactivated or incorporated into the vehicle&#39;s on-board security system. If incorporated into the vehicle&#39;s on-board security system, the control system may be configured to activate an alarm when the radar sensor detects motion after the preset period of time has elapsed. 
     In another aspect of the invention, the plurality of alert modes may include at least one externally audible alarm and at least one externally visible alarm. The alert system may include a wireless telecommunications link and the plurality of alert modes may include a pre-recorded message (e.g., a pre-recorded text message or a pre-recorded audible message) that is transmitted by the alert system using the wireless telecommunications link. The system may include a wireless telecommunications link and an in-cabin camera, and the alert system may transmit a current image of the passenger cabin using the wireless telecommunications link when the radar sensor detects motion within the passenger cabin. 
     In another aspect of the invention, a vehicle status sensor may be coupled to the control system and the control system may be configured to activate the radar sensor when it receives the first control signal from the monitoring system and the vehicle off control signal from the vehicle status sensor. 
     In another aspect of the invention, the monitoring system may include at least one sensor (e.g., a pressure-based sensor, a capacitance-based sensor) integrated into the vehicle&#39;s driver seat, where the monitoring system outputs the first control signal when the driver exits the driver seat and outputs the second control signal when the driver sits on the driver seat. 
     In another aspect of the invention, the monitoring system may include a short range wireless identification system, where the monitoring system outputs the second control signal when the short range wireless identification system identifies a device (e.g., a key fob) with a unique user identifier and determines that the device is within the passenger cabin, and where the monitoring system outputs the first control signal when the wireless identification system determines that the device is outside of the passenger cabin. 
     In another aspect of the invention, the system may include a system over-ride switch. If the over-ride switch is activated, the control system will not activate the radar sensor. If the alert system is already activated, activation of the over-ride switch will deactivate the alert system. The system over-ride switch may be comprised of at least one sensor (e.g., a pressure-based sensor, a capacitance-based sensor) integrated into the driver seat, where sitting on the driver seat will activate the system over-ride switch. If the system over-ride includes a pressure-based sensor, the system may utilize a cut-off weight such that the over-ride switch is only activated if the pressure applied to the at least one pressure-based sensor is greater than the cut-off weight. 
     A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It should be understood that the accompanying figures are only meant to illustrate, not limit, the scope of the invention and should not be considered to be to scale. Additionally, the same reference label on different figures should be understood to refer to the same component or a component of similar functionality. 
         FIG. 1  provides a system level diagram of the primary vehicle systems utilized in at least one preferred embodiment of the invention; 
         FIG. 2  provides a side view of a pair of sensors mounted in the vehicle&#39;s headliner; 
         FIG. 3  provides a side view of a pair of sensors mounted in the back of an adjacent seat; 
         FIG. 4  provides a side view of a pair of sensors mounted in a headliner mounted display; 
         FIG. 5  provides a top view of a pair of sensors mounted in the vehicle&#39;s headliner; 
         FIG. 6  provides a top view of a single sensor mounted in the vehicle&#39;s headliner; 
         FIG. 7  illustrates the basic methodology of the invention; 
         FIG. 8  illustrates a modification of the methodology shown in  FIG. 7  that includes a system over-ride feature; 
         FIG. 9  illustrates a modification of the methodology shown in  FIG. 8  in which activation of the system over-ride feature is based on whether or not the front vehicle seat(s) is occupied; 
         FIG. 10  illustrates the use of sensors within a vehicle seat; 
         FIG. 11  illustrates a modification of the methodology shown in  FIG. 8  in which activation of the system over-ride feature is based on whether or not the front vehicle seat(s) is occupied and if occupied, the weight of the occupying party; 
         FIG. 12  illustrates a modification of the methodology shown in  FIG. 8  in which activation of the system over-ride feature is based on whether or not the driver remains in the car once the vehicle has been turned off; 
         FIG. 13  illustrates a modification of the methodology shown in  FIG. 12  in which activation of the child detection system is based solely on proximity of the driver to the car; 
         FIG. 14  illustrates a modification of the methodology shown in  FIG. 7  in which the type of alert varies over time after an unattended child or pet has been detected by the system; 
         FIG. 15  illustrates a modification of the methodology shown in  FIG. 7  in which the type of alert varies based on in-cabin temperature; 
         FIG. 16  illustrates a modification of the methodology shown in  FIG. 7  in which the type of alert may vary based on either elapsed time or in-cabin temperature; and 
         FIG. 17  illustrates a modification of the methodology shown in  FIG. 7  that illustrates the use of the child/pet sensor in the vehicle&#39;s on-board security system. 
     
    
    
     DESCRIPTION OF THE SPECIFIC EMBODIMENTS 
     As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises”, “comprising”, “includes”, and/or “including”, as used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” and the symbol “/” are meant to include any and all combinations of one or more of the associated listed items. Additionally, while the terms first, second, etc. may be used herein to describe various steps or calculations, these steps or calculations should not be limited by these terms, rather these terms are only used to distinguish one step or calculation from another. For example, a first calculation could be termed a second calculation, similarly, a first step could be termed a second step, similarly, a first component could be termed a second component, all without departing from the scope of this disclosure. 
       FIG. 1  provides a block diagram of an exemplary detection and response system  100  for use with a preferred embodiment of the invention. System  100  may be integrated into an electric vehicle (EV), a vehicle utilizing an internal combustion engine (ICE), or a hybrid vehicle, where a hybrid vehicle utilizes multiple sources of propulsion including an electric drive system. It should be understood that control system  100  is but one possible configuration and that other configurations may be used while still retaining the functionality of the invention. For example, not every embodiment of the invention will necessarily use the external lights and/or the horn in responding to the detection of an unattended child or pet. Additionally, one or more of the elements shown in  FIG. 1  can be grouped together in a single device, and/or circuit board, and/or integrated circuit. 
     Control system  100  includes a system controller  101  comprised of a central processing unit (CPU)  103  and a memory  105 . Preferably system controller  101  also serves as the vehicle&#39;s management system (i.e., vehicle system controller). Memory  105  may be comprised of EPROM, EEPROM, flash memory, RAM, a solid state disk drive, a hard disk drive, or any other memory type or combination of memory types. Assuming a user interface  109  that includes a display, and depending upon the type of display used in the interface as well as the capabilities of CPU  103 , controller  101  may also include a graphical processing unit (GPU)  107 . CPU  103  and GPU  107  may be separate or contained on a single chip set. 
     As noted above, preferably an interface  109  is coupled to controller  101 . The interface may be comprised of a single interface, for example a touch-screen display, or a combination of user interfaces such as push-button switches, capacitive switches, slide or toggle switches, gauges, display screens, warning lights, audible warning signals, etc. Interface  109  allows the driver, or a passenger, to interact with the vehicle management system, for example inputting data into the navigation system, altering the heating, ventilation and air conditioning (HVAC) system, controlling the vehicle&#39;s entertainment system (e.g., radio, CD/DVD player, etc.), adjusting vehicle settings (e.g., seat positions, light controls, etc.), and/or otherwise altering the functionality of the vehicle. Typically interface  109  also provides a way for the vehicle management system to communicate information to the driver and/or passenger, information such as a navigation map or driving instructions as well as the operating performance of any of a variety of vehicle systems (e.g., battery pack charge level for an electric car, fuel level for the engine in a hybrid or ICE-based vehicle, selected gear, current entertainment system settings such as volume level and selected track information, external light settings, current vehicle speed, current HVAC settings such as cabin temperature and/or fan settings, etc.). Interface  109  may also be used to communicate an operating system malfunction (battery system not charging properly, low oil pressure for an ICE-based vehicle, low tire air pressure, etc.). 
     Coupled to controller  101  is a sensor  111  that is used to determine whether a child, or pet, is still in the car after the car has been placed in park and the driver has left the vehicle. The present invention may be configured to utilize any of a variety of different types of sensors  111 , alone or in combination. Preferably sensor(s)  111  is a pulse Doppler radar-based sensor, also referred to herein as an interior radar sensor. The inventors have found that this type of sensor can reliably detect the small amount of movement associated with the breathing of an infant, small child or pet, even if the child is covered with several layers of covers. While interior radar sensors are preferred, it should be understood that the invention may utilize a variety of transducer types, e.g., electromagnetic transducers, ultrasonic transducers, etc., to detect the presence of an unattended child or pet; that these transducers may emit a continuous signal, a time varying signal or a spatially varying signal; and that these transducers may use separate transmitters and receivers or they may use transceivers that are capable of both transmitting and receiving the monitor signal. While the invention may also utilize sensors incorporated into the vehicle seats (e.g., pressure or capacitive sensors), the inventors have found that these types of sensors are less reliable than a transducer-based sensor for the present application since seat-based sensors are prone to false signals, for example if an inanimate object (e.g., child seat) is left in the vehicle seat and the system has not been properly calibrated to compensate for the inanimate object. 
     Child/pet sensor or sensors  111  may be mounted in a variety of locations within the car, thus allowing sensor placement to be optimized for the passenger compartment and seat configuration of a particular car, as well as the selected type of sensor(s).  FIGS. 2-4  provide side views of three exemplary mounting configurations suitable for use with a transducer-based detection system such as the preferred radar based transducer. In  FIG. 2 , transducers  201  and  203  are mounted to, or within, the vehicle&#39;s headliner  205 . In  FIG. 3 , transducers  201  and  203  are mounted to, or within, the seat back  301  of seat  303 , where seat  303  is the seat in front of monitored seat  305 . In  FIG. 4 , transducers  201  and  203  are mounted to a display  401 , for example a display used with a rear seat entertainment system. It should be understood that in order to monitor the entire rear seat, in some configurations and for some types of sensors it may be necessary to mount multiple sensors across the width of the car. For example,  FIG. 5  provides a top view of the passenger cabin of a car  500 , this view showing a pair of transducers  501  and  503  that are mounted adjacent to the left and right portions of rear seat  505 , where the transducers are preferably mounted to, or within, the headliner. It will be appreciated that while two transducers are shown in each of these exemplary embodiments, the invention may use a single transducer or more than two transducers. For example,  FIG. 6  provides a view similar to that of  FIG. 5 , except that a single transducer  601  is mounted to the headliner. Additionally, while the exemplary transducers are transceivers, as previously noted separate transmitter and receiver transducers may be used. Lastly, while the transducer locations shown in  FIGS. 2-6  focus on monitoring the second row of seats where a child seat would normally be located, the invention is equally applicable to other transducer mounting locations that would allow other areas of the car, e.g., the front seats, to be monitored. 
       FIG. 7  illustrates the basic methodology of the invention. During normal vehicle operation (step  701 ), controller  101  monitors vehicle status (step  703 ). Vehicle status may be determined by monitoring an on/off sensor  113 . Sensor  113  may, for example, be coupled to the vehicle&#39;s ignition switch or the vehicle&#39;s on/off switch. As long as the status of the vehicle remains ‘on’ (step  705 ), controller  101  simply continues to perform monitoring step  703 . Once controller  101  determines that the status of the vehicle has changed to ‘off’ (step  707 ), controller  101  initiates monitoring of the child/pet sensor  111  (step  709 ). It will be appreciated that other indicators may be used by controller  101  to switch the vehicle&#39;s status from ‘on’ to ‘off’. 
     During monitoring step  709 , controller  101  monitors the output from sensor(s)  111 . In one embodiment, if no child (or pet) is detected (step  711 ) the system immediately enters into standby mode (step  713 ). The vehicle&#39;s standby mode may be configured in a variety of ways, depending upon the design objectives of the manufacturer. In some configurations, in standby mode the child detection system is turned-off, thereby minimizing off-line power consumption. In other configurations, and as described in detail below, in standby mode the child detection system is used in a theft-prevention mode, thus helping to prevent vehicle break-ins or at least minimize theft after a vehicle break-in. 
     While the system may be configured to immediately enter into stand-by mode if no child or pet is detected in step  711  as described above, preferably as shown in  FIG. 7  the system is configured to monitor sensor  111  for a period of time, as provided by a timer  115 , prior to making this determination (step  715 ). A typical period of time used in step  715  is less than 30 minutes, preferably less than 15 minutes, and more preferably in the range of 5 to 10 minutes. It should be understood, however, that a shorter period of time or a longer period of time may be used during this step. If no child or pet is detected (step  711 ) and the time allotted for detection is reached (step  717 ), then the system enters into standby mode (step  713 ), where the standby mode is as described above. If, however, a child or pet is detected (step  719 ), then controller  101  activates a warning or alert system (step  721 ). 
     The warning/alert system activated in step  721  may take any of a variety of forms as described in detail below, and may be intended to alert any of a variety of parties as to the detection of an unattended child or pet. Suitable parties to receive such a warning include the car&#39;s driver or owner, third parties that are in close proximity to the car (e.g., pedestrians near the car or people in nearby buildings), third parties under contract to monitor the vehicle&#39;s detection system (e.g., vehicle manufacturer or an alarm monitoring company), and/or emergency/health officials (e.g., police, paramedics, fire department). Examples of alarms that may be used by controller  101  to alert a nearby person of the unattended child or pet include both externally audible alarms  117  (e.g., car horn, on-board siren) and externally visible alarms  119  (e.g., internal and/or external car lights). In order to alert parties that are not in the immediate vicinity of the car, controller  101  uses a wireless telecommunication link  121  to send an appropriate alert message. The eCall system used in Europe is an example of such an automated emergency messaging service. Telecommunications link  121  may utilize any of a variety of different standards and protocols including, but not limited to, GSM, EDGE, UMTS, CDMA2000, DECT, WiFi and WiMax. The alert message may be in the form of a pre-recorded audible message that may, for example, be stored in memory  105 . Alternately or in conjunction with the pre-recorded audible message, a preset text alert may be transmitted via communications link  121 . The audible or textual message may also be sent via an application on the user&#39;s phone or other device. Alternately or in conjunction with the pre-recorded audible message and/or preset text alert, controller  101  may transmit a picture or video captured using an in-cabin camera  123 , where the picture or video is of the inside of the passenger cabin in general, and preferably of the detected child or pet in particular. 
     Once the alert system has been activated (step  721 ), preferably the system continues to transmit an alert of one form or another until the system has been deactivated (step  723 ). In the procedure illustrated in  FIG. 7 , the system can be configured to deactivate once the status of the vehicle switches from ‘off’ to ‘on’. Alternately or in addition to this form of deactivation, controller  101  can monitor the car doors with door sensors  127  and deactivate the alert system when a car door is opened. It will be appreciated that other means may be used to deactivate the alert system once it has been activated. 
     In some situations, the driver may wish to park their car, turn off the power to the car (i.e., ignition or power off), and sit with their child or pet. For example, the child may be napping and the parent or caregiver does not wish to wake the child. In this situation the methodology shown in  FIG. 7  would issue an alert (step  721 ) even though the child was not in danger and the parent/caregiver was in attendance. A work-around for this situation is to provide a child detection system on/off switch, preferably accessible through user interface  109 , as illustrated in  FIG. 8 . As shown, in addition to checking vehicle status (step  703 ), controller  101  also checks to see if the system over-ride has been activated (step  801 ). If the system over-ride has been activated (step  803 ), the controller immediately enters the standby mode (step  713 ). If the system over-ride has not been activated (step  805 ), the controller initiates monitoring for unattended children/pets using sensor  111  (step  709 ). In this embodiment once the alert system has been activated (step  721 ), preferably the user can deactivate the system (step  723 ) using the system over-ride. Additionally, the system can be configured to deactivate once the status of the vehicle switches from ‘off’ to ‘on’, and/or when controller  101  determines that a car door has been opened. 
     While switching the child detection system off via the user interface as shown in  FIG. 8  is one approach to over-riding the system, it should be understood that there are other approaches that may be used to initiate a system over-ride. For example in the process shown in  FIG. 9 , controller  101  monitors an occupant detection sensor, for example one or more sensors  125  located in the driver&#39;s seat, or located in both front vehicle seats (step  901 ). Sensors  125  may be pressure-based sensors or capacitance-based sensors.  FIG. 10  illustrates the inclusion of sensors  125  in a vehicle seat  1001 . If the output from sensor  125  indicates the presence of someone in the driver&#39;s seat (step  903 ) (or the presence of someone in the front passenger seat if the system is configured to monitor both front seats), then the controller immediately enters the standby mode (step  713 ). If the output from sensor  125  indicates the front seat(s) is vacant (step  905 ), then controller  101  initiates the monitoring sequence (step  709 ). It will be appreciated that if sensors  125  are pressure sensitive, the sensors may be calibrated as illustrated in  FIG. 11 , thereby allowing the system to only be over-ridden if the pressure sensitive seat sensors detect weight above a preset value (step  1101 ). By factoring in weight, the child detection system can be configured to operate even if a small weight, such as that of a small pet, is detected. Preferably in this embodiment the user is able to set the cut-off weight used in step  1103 , for example using interface  109 , thus allowing the user to configure the system for their particular pet or situation. In the embodiments shown in  FIGS. 9 and 11 , preferably the system is configured so that once the alert system has been activated (step  721 ), the user can deactivate the system (step  723 ) by opening a car door, and/or switching the vehicle from ‘off’ to ‘on’, and/or seating in a car seat, thereby over-riding the system. 
       FIG. 12  illustrates another modification of the basic methodology shown in  FIG. 7 , the modified methodology including an alternate technique for determining whether or not to activate the system&#39;s child detection sensor. In this embodiment in addition to determining vehicle status (step  703 ) as described above, the controller also determines whether or not the driver has left the car (step  1201 ). Preferably controller makes this determination without any aid from the driver, i.e., preferably the driver is not required to switch the child detection system on or otherwise indicate that they are leaving the car. In the preferred approach, controller  101  monitors driver proximity to the vehicle in order to determine whether or not the driver has left the car. 
     In the procedure illustrated in  FIG. 12 , controller  101  determines driver proximity by monitoring the driver&#39;s key fob. Alternately, the system can be configured to identify and track the driver based on the user&#39;s smartphone or another device with a unique user identifier. Preferably controller  101  tracks the location of the driver&#39;s key fob or other uniquely identifiable device (e.g., smartphone) using communication link  121  and a short range wireless technology such as a radio-frequency identification (RFID) system or a Bluetooth wireless system. As long as the driver remains in the car (step  1203 ), the child detection system remains inactive. Once the driver leaves the car (step  1205 ) as determined by controller  101 , then the controller initiates monitoring for unattended children/pets using sensor  111  (step  709 ). It should be understood that the order of steps  703  and  1201  may be reversed. 
       FIG. 13  illustrates a simplification of the procedure shown in  FIG. 12 . The illustrated method assumes that if the driver has left the car, as evidenced by the driver&#39;s key fob or similar uniquely identifiable device moving out and away from the car, then the status of the car must be ‘off’. Therefore once the driver leaves the car (step  1205 ), the system activates child/pet detection sensor  111  and begins the monitoring procedure as described above. In the embodiments shown in  FIGS. 12 and 13 , preferably the system is configured to allow system deactivation, once the alert system has been activated (step  721 ), by returning the driver&#39;s key fob (or similar uniquely identifiable device) to the car, and/or opening a car door, and/or switching the vehicle from ‘off’ to ‘on’. 
     Regardless of the embodiment, once controller  101  determines that a child or pet has been left unattended in the car (step  719 ), the system can be configured to activate any of a variety of different alerts (e.g., audible, visual, textual, phone-based, etc.) that are intended to notify any of a variety of different parties of the unattended child/pet (e.g., parties in proximity to the car, parties not in the immediate vicinity, emergency/health officials, etc.). In the preferred embodiment, the system is configured to automatically vary the alert mode, i.e., the selected alert, based upon how long the child or pet has been left unattended in the car. The intent of this approach is to decrease the risk of injury or death of the unattended child or pet by quickly escalating the type of alert from one intended to warn an individual or a relatively small group of individuals to one intended to alert a much larger group and/or an emergency service. Thus as shown in the exemplary embodiment of  FIG. 14 , after the alert is initially transmitted (step  721 ), and assuming that the system is not deactivated in step  725 , then controller  101  compares the elapsed time since the alarm was activated to a preset value, y (step  1401 ). The preset value is preferably set by the manufacturer, although the system may be configured to allow this value to be set by the end user or a third party. As long as the elapsed time remains below this preset value (step  1403 ) and the system is not deactivated (step  727 ), the system continues to transmit the initially transmitted alert. Once the elapsed time exceeds the preset value (step  1405 ), and assuming that the system has not been deactivated, the alert mode is altered (step  1407 ) and the preset time value used in step  1401  is increased (step  1409 ). This loop continues, increasing the alert until the system is deactivated. It should be understood that while this mode of escalating alerts is shown relative to the basic methodology of  FIG. 7 , it is equally applicable to the other embodiments of the invention (e.g., the embodiments shown in  FIGS. 8, 9, 11-13 ). 
     While the type of alert issued by controller  101  in step  721  can take any of the previously described forms, preferably in the methodology illustrated in  FIG. 14  the initially issued alert is sent to the driver. This initial alert may be in the form of a text message and/or a pre-recorded audible message and/or a smart device (e.g., phone) application push. The initial alert may be accompanied by an image (e.g., photo) of the interior of the passenger cabin taken by camera  123 , the image preferably including the unattended child or pet. If the driver does not immediately return and deactivate the system, once the elapsed time exceeds the preset time (e.g., after a relatively short time period of a few minutes), the controller alters the alert mode. Preferably the next alert mode is intended to alert nearby parties, i.e., people walking by the car or in nearby buildings. This next alert mode typically will sound the horn and/or flash the outside lights. If the system still remains active, once the elapsed time exceeds the next preset (e.g., typically after a few more minutes), then the controller will preferably alter the alert mode to initiate a call and send an audible and/or textual message to a private and/or public emergency center (e.g., alarm monitoring company, police, paramedics, fire department, etc.). 
     In addition to transmitting alerts, preferably controller  101  is configured to actively control the temperature within the vehicle using the car&#39;s HVAC system  129 . If the system is configured to provide controller  101  with HVAC control, as preferred, then one of the alert modes set in step  1407  may be to initiate passenger cabin air circulation, thereby lowering cabin temperature by actively circulating in-cabin air with outside air. Depending upon vehicle and system configuration, during this step controller  101  may also be configured to turn on the vehicle&#39;s air conditioning system. When controller  101  is provided with HVAC system  129  control, preferably if the driver does not immediately return and deactivate the system after transmission of the initial alert, then once the elapsed time exceeds the first preset time period the controller will alter the alert mode (step  1407 ) to a mode in which the system attempts to maintain in-cabin air quality and temperature by activating HVAC system  129 . Activation of the audible and/or visible alerts (e.g., horn and/or external flashing lights) may precede activation of the HVAC system, or may accompany activation of the HVAC system, or may be delayed until the next change in alert mode. 
     As described above relative to all embodiments, and as illustrated in the exemplary embodiment shown in  FIG. 14 , the system can be configured to alter the type of alert based on the amount of time that has elapsed since an unattended child or pet is first detected. In a modification of this approach that is illustrated in the exemplary embodiment shown in  FIG. 15 , and that is also applicable to all embodiments, the system can be configured to alter the type of alert based on in-cabin temperature. The benefit of this approach is that the rate of alert escalation is based directly on risk to the child (or pet) since it is based on in-cabin temperature. In contrast, the rate of alert escalation described above relative to  FIG. 14  will vary at the same rate, regardless of in-cabin temperature. In the configuration shown in  FIG. 15 , controller  101  monitors an in-cabin temperature sensor  131 . 
     As shown in  FIG. 15 , after the alert is initially transmitted (step  721 ), and assuming that the system is not deactivated in step  725 , then controller  101  compares the in-cabin temperature to a preset value, T (step  1501 ). As in the embodiment illustrated in  FIG. 14 , preferably the preset value is set by the manufacturer or an authorized third party. As long as the in-cabin temperature remains below this preset value (step  1503 ) and the system is not deactivated (step  727 ), the system continues to transmit the initially transmitted alert. Once the in-cabin temperature exceeds the preset value (step  1505 ), and assuming that the system has not been deactivated, the alert mode is altered (step  1507 ) and the value for the preset temperature is increased (step  1509 ). This loop continues, increasing the alert until the system is deactivated. This technique for altering the transmitted alert is applicable to all embodiments of the invention, even though it is shown relative to the basic methodology. 
     Since the health risks associated with heat exposure are based both on the exposure temperature and the length of exposure, in at least one embodiment and as illustrated in  FIG. 16 , the alert mode is altered based on the amount of time that has elapsed since an unattended child or pet is first detected (e.g.,  FIG. 14 ) as well as the in-cabin temperature (e.g.,  FIG. 15 ). As shown in  FIG. 16 , if the in-cabin temperature is less than the preset temperature, T (step  1503 ), then the system compares the elapsed time to a preset value, y (step  1401 ). If both the in-cabin temperature and the elapsed time are less than the corresponding presets, the system continues to transmit the current alert mode. If either the in-cabin temperature is greater than the preset temperature (step  1505 ), or the elapsed time is greater than the preset time value (step  1405 ), then the alert mode is altered (step  1601 ) and the values for the presets are increased (step  1603 ). This loop continues, increasing the alert mode until the system is deactivated. This technique for altering the mode of the transmitted alert is applicable to all embodiments of the invention, even though it is only shown relative to the basic methodology. It should be understood that the order of steps  1401  and  1501  may be reversed. 
     As previously noted, if a child or pet is not detected in step  709 , either immediately or after a preset period of time has elapsed without child/pet detection, the system enters into a standby mode (step  713 ). The system can be configured such that in standby mode, the child/pet detection system is turned off, thus minimizing power consumption. The system can also be configured such that in standby mode, the child/pet detection system is incorporated into the vehicle&#39;s on-board security system. As used as part of the on-board security system, the sensitivity of sensor  111  may or may not be changed from the setting used when the sensor is operating as a child/pet sensor. Regardless of whether or not the sensor sensitivity is altered when operating in this mode, preferably the alert that is activated when a possible break-in is detected is different from that described above. When a break-in is detected, a typical vehicle security system will immediately attempt to get the attention of people passing, for example by sounding the horn and/or flashing the lights. Additionally, this type of security system will often immediately notify the authorities and/or a private security company that is under contract to monitor the on-board system. A typical on-board security system will not, however, vary the alarm based on either elapsed time or in-cabin temperature. 
       FIG. 17  illustrates an embodiment, based on the methodology shown in  FIG. 7 , in which sensor  111  is incorporated into the vehicle&#39;s on-board security system whenever the system enters into standby mode (step  713 ). It should be understood that the child/pet detection of the invention may be incorporated into the vehicle&#39;s security system in any of the embodiments, i.e., those illustrated in  FIGS. 7-9 and 11-16 . As shown in  FIG. 17 , once the system enters into standby mode (step  713 ), controller  101  continues to monitor sensor  111  (step  1701 ). If sensor detects motion (step  1703 ), controller  101  activates a preconfigured alarm (step  1705 ). The preconfigured alarm activated in step  1705  may use an audible alarm  117 , a visible alarm  119 , and/or a message sent via communication link  121 . The system may also use camera  123  to send an interior image of the passenger cabin via communication link  121 . 
     Systems and methods have been described in general terms as an aid to understanding details of the invention. In some instances, well-known structures, materials, and/or operations have not been specifically shown or described in detail to avoid obscuring aspects of the invention. In other instances, specific details have been given in order to provide a thorough understanding of the invention. One skilled in the relevant art will recognize that the invention may be embodied in other specific forms, for example to adapt to a particular system or apparatus or situation or material or component, without departing from the spirit or essential characteristics thereof. Therefore the disclosures and descriptions herein are intended to be illustrative, but not limiting, of the scope of the invention.