Abstract:
An occupant support includes a vehicle seat, a sensor coupled to the vehicle seat, and a controller coupled to the sensor. The sensor provides a signal to the controller and the controller processes and responds to the sensed signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 62/345,253, filed Jun. 3, 2016, which is expressly incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to a vehicle seat, and particularly to a vehicle seat including a sensor. More particularly, the present disclosure relates to a vehicle seat including one or more sensors coupled to a controller for determining occupant biometrics. 
       SUMMARY 
       [0003]    According to the present disclosure, an occupant support includes a vehicle seat, a sensor coupled to the vehicle seat, and a controller coupled to the sensor. The sensor provides a signal to the controller and the controller responds to the sensed signal. 
         [0004]    In illustrative embodiments, a controller includes a sensor module, a filter module, and a biometrics module. The sensor module retrieves sensor data indicative of an occupant of a vehicle seat from one or more sensors of a vehicle. The filter module determines a filter function in a frequency range in which useful biological data may be derived. The filter function identifies one or more frequencies of noise in the sensor data and applies the filter function to the sensor data to generate filtered sensor data. The biometrics module determines biometric data associated with the occupant based on the filtered sensor data. In illustrative embodiments, the one or more sensors include a piezoelectric bend sensor, an accelerometer, or a microphone. 
         [0005]    In illustrative embodiments, determining the filter function includes determining a notch filter at a transmission frequency of the vehicle seat while occupied by a passenger. Determining the notch filter may include determining a static resonant frequency of the vehicle seat or determining the resonant frequency based on a size of the occupant. 
         [0006]    In illustrative embodiments, determining the size of the occupant includes receiving sensor data from one or more sensors indicative of the size of the occupant and determining the size of the occupant based on the sensor data. Determining the size of the occupant includes receiving data indicative of the size of the occupant from a second controller of the vehicle via a vehicle network. 
         [0007]    In illustrative embodiments, determining the filter function includes determining a notch filter at a frequency based on a transmission frequency of the vehicle seat. In illustrative embodiments, determining the filter function includes receiving vehicle state data from a second controller of the vehicle via a vehicle network, and determining a notch filter at a frequency based on the vehicle state data. The vehicle state data may be indicative of engine load, engine speed, or vehicle speed. 
         [0008]    In illustrative embodiments, determining the filter function includes characterizing the noise based on the sensor data and adapting the filter function based on the sensor data in response to characterization of the noise. In illustrative embodiments, determining the biometric data associated with the occupant includes determining a heart rate, a heart rate variability, or a respiration rate of the passenger. 
         [0009]    In illustrative embodiments, a method includes the steps of receiving, by a controller of a vehicle, sensor data indicative of an occupant of a vehicle seat from one or more vibration sensors of the vehicle; determining, by the controller, a filter function in a biometric frequency range, wherein the filter function identifies one or more frequencies of noise in the sensor data; applying, by the controller, the filter function to the sensor data to generate filtered sensor data; and determining, by the controller, biometric data associated with the occupant based on the filtered sensor data. In illustrative embodiments, the one or more vibration sensors include a piezoelectric sensor, an accelerometer, or a microphone. 
         [0010]    In illustrative embodiments, determining the filter function includes determining a notch filter at a resonant frequency of the vehicle seat while occupied. Determining the notch filter may include determining a transmission frequency of the vehicle seat based on a size of the occupant. In an embodiment, determining the size of the occupant includes receiving sensor data from one or more sensors indicative of the size of the occupant and determining the size of the occupant based on the sensor data. In an illustrative embodiment, determining the size of the occupant includes receiving data indicative of the size of the occupant from a second controller of the vehicle via a vehicle network. 
         [0011]    In illustrative embodiments, determining the filter function includes determining a notch filter at a frequency based on a transmission frequency of an occupied seat. In illustrative embodiments, determining the filter function includes receiving vehicle state data from a second controller of the vehicle via a vehicle network and determining a notch filter at a frequency based on the vehicle state data. The vehicle state data may be indicative of engine load, engine speed, or vehicle speed. 
         [0012]    In illustrative embodiments, determining the filter function includes characterizing the noise based on the sensor data and adapting the filter function based on the sensor data in response to characterizing the noise. In illustrative embodiments, determining the biometric data associated with the occupant includes determining a heart rate, a heart rate variability, or a respiration rate. 
         [0013]    One or more computer-readable storage media in accordance with the present disclosure include a plurality of instructions that in response to being executed cause a controller to receive sensor data indicative of an occupant of a vehicle seat from one or more vibration sensors of the vehicle; determine a filter function in a biometric frequency range, wherein the filter function identifies one or more frequencies of noise in the sensor data; apply the filter function to the sensor data to generate filtered sensor data; and determine biometric data associated with the occupant based on the filtered sensor data. In illustrative embodiments, the one or more vibration sensors include a piezoelectric sensor, an accelerometer, or a microphone. 
         [0014]    Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0015]    The detailed description particularly refers to the accompanying figures in which: 
           [0016]      FIG. 1  is a diagrammatic view of a system in accordance with the present disclosure showing a vehicle seat, a controller, and multiple vibration sensors coupled to the controller; 
           [0017]      FIG. 2  is a diagrammatic view of at least one embodiment of an environment that may be established by a controller of  FIG. 1 ; 
           [0018]      FIG. 3  is a flow diagram illustrating at least one embodiment of a method for determining occupant biometric data that may be executed by the controller of  FIGS. 1 and 2 ; and 
           [0019]      FIG. 4  is a chart illustrating experimental results that may be achieved by the system of  FIGS. 1-3  where the first bar for each occupant size in each operating state shows percent correlation to an ECG reference before the system of the present disclosure is applied and the second bar for each occupant size in each operating states shows percent correlation to the ECG reference after the system of the present disclosure is applied. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    An embodiment of a system  10  in accordance with the present disclosure is shown in  FIG. 1 . The system  10  may be included in a vehicle such as a car, truck, boat, airplane, or any other suitable alternative. The illustrative system  10  includes multiple controllers  12 , a vehicle seat  14 , multiple vibration sensors  16 , and a vehicle network  18 . As described further below, in use, a controller  12  may receive sensor data from the sensors  16  and determine biometric data relating to an occupant of the vehicle seat  14  based on the sensor data. 
         [0021]    The vehicle seat  14  may be embodied as an adjustable or otherwise movable vehicle seat and may include multiple parts, including a seat bottom, a seat back, and/or a head restraint. The vehicle seat  14  may include one or more controllers, actuators, and/or other components to provide one or more therapies. Therapies may include active surface movement including massage, lumbar and bolster, postural adjustment and other moveable surfaces that enable and/encourage postural movement. Climate therapies may include heat, cool, venting, scent, air quality, lighting (red/blue), and music and may also be used. 
         [0022]    As shown, the vehicle seat  14  is coupled to multiple sensors  16 . Each of the sensors  16  may be embodied as any electronic device capable of measuring vibrations generated by biological processes of an occupant of the vehicle seat (e.g., vibrations caused by the occupant&#39;s heartbeat, respiration, or other processes). In the illustrative embodiment, the sensors  16  are embodied as piezoelectric strips. In other embodiments, the sensors  16  may include PV piezoelectric film, piezoelectric cables, accelerometers (piezoelectric), microphones, impedance field, combinations thereof, or any other suitable vibration sensors. The sensors  16  may be included in, incorporated in, or otherwise attached to the vehicle seat  14 . Thus, in some examples, the sensors  16  may be covered with vehicle seat trim and accordingly spaced apart from the occupant of the vehicle seat  14 . Additionally, although illustrated as including four sensors  16 , the system  10  may include a different number and/or arrangement of sensors  16 . 
         [0023]    The system  10  further includes multiple controllers  12 , which each may be embodied as an electronic control unit or other controller configured to perform the functions described herein. In particular, and as described further below, a controller  12  (e.g., a controller  12  coupled to the vehicle seat  14 ) may be configured to receive sensor data from the sensors  16  and determine biometric data relating to the occupant of the vehicle seat  14  based on the sensor data. Thus, the system  10  may measure occupant biometrics even in a noisy environment such as the interior of a vehicle when driving. Additionally, the system  10  may measure occupant biometrics with the sensors  16  spaced apart from the occupant&#39;s body (e.g., to allow for seat trim and clothing), without requiring the sensors  16  to be attached to the occupant. By measuring the occupant biometrics, the system  10  may provide biofeedback to the occupant, trigger or suggest appropriate therapies, or perform other applications. 
         [0024]    Each controller  12  may be embodied as any device capable of performing the functions described herein. For example, each controller  12  may be embodied as an electronic control unit, embedded controller, control circuit, microcontroller, computing device, on-board computer, and/or any other any other computing device capable of performing the functions described herein. As shown in  FIG. 2 , an illustrative controller  12  includes a processor  20 , an I/O subsystem  22 , a memory  24 , a data storage device  26 , and communication circuitry  28 . Of course, the controller  12  may include other or additional components, such as those commonly found in an electronic control unit (e.g., various input/output devices), in other embodiments. Additionally, in some embodiments, one or more of the illustrative components may be incorporated in, or otherwise form a portion of, another component. For example, the memory  24 , or portions thereof, may be incorporated in the processor  20  in some embodiments. 
         [0025]    The processor  20  may be embodied as any type of processor capable of performing the functions described herein. For example, the processor  20  may be embodied as a microcontroller, digital signal processor, single or multi-core processor(s), or other processor or processing/controlling circuit. Similarly, the memory  24  may be embodied as any type of volatile or non-volatile memory or data storage capable of performing the functions described herein. In operation, the memory  24  may store various data and software used during operation of the processor  20  such as operating systems, applications, programs, libraries, and drivers. The memory  24  is coupled to the processor  20  via the I/O subsystem  22 , which may be embodied as circuitry and/or components to facilitate input/output operations with the processor  20 , the memory  24 , and other components of the controller  12 . For example, the I/O subsystem  22  may be embodied as, or otherwise include, memory controller hubs, input/output control hubs, firmware devices, communication links (i.e., point-to-point links, bus links, wires, cables, light guides, printed circuit board traces, etc.) and/or other components and subsystems to facilitate the input/output operations. In some embodiments, the I/O subsystem  22  may form a portion of a system-on-a-chip (SoC) and be incorporated, along with the processor  20 , the memory  24 , and other components of the controller  12 , on a single integrated circuit chip. 
         [0026]    The data storage device  26  may be embodied as any type of device or devices configured for short-term or long-term storage of data such as, for example, memory devices and circuits, memory cards, hard disk drives, solid-state drives, read-only memory, or other data storage devices. The communication circuitry  28  of the controller  12  may be embodied as any communication circuit, device, or collection thereof, capable of enabling communications between the controller  12  and other devices of the vehicle seat  14  and/or the vehicle. The communication circuitry  28  may be configured to use any one or more communication technology (e.g., wireless or wired communications) and associated protocols (e.g., Ethernet, controller area network (CAN), local interconnect network (LIN), Bluetooth®, Wi-Fi®, etc.) to effect such communication. In some embodiments, the communication circuitry  28  may include one or more general-purpose I/O pins, analog interfaces, solid state motor control electronics, and/or other circuitry that may be used to interface with or otherwise control features of the vehicle seat  14  (e.g., seat motion, therapy, or other features). 
         [0027]    As further shown in  FIG. 1 , the controllers  12  and the sensors  16  may be configured to transmit and/or receive data with each other and/or other devices over the vehicle network  18 . The vehicle network  18  may be embodied as any bus, network, or other communication facility used to communicate between devices in the vehicle. For example, the vehicle network  18  may be embodied as a wired or wireless local area network (LAN), controller area network (CAN), and/or local interconnect network (LIN). Thus, the vehicle controllers  12  may include one or more additional electronic control units, embedded controllers, engine computers, or other computing devices used to control various vehicle functions. In particular, the controller  12  may be configured to communicate with one or more additional vehicle controllers  12  via the vehicle network  18  to determine the state of the vehicle, for example to determine whether the ignition is on, to determine engine speed or engine load, to determine vehicle speed, or to determine other vehicle state. Additionally or alternatively, although shown as communicating directly with the vehicle network  18 , it should be understood that in some embodiments the sensors  16  may be coupled directly to one or more controllers  12  (e.g., a seat controller  12 ) without using the vehicle network  18 . 
         [0028]    Referring now to  FIG. 2 , in the illustrative embodiment, a controller  12  establishes an environment  100  during operation. The illustrative environment  100  includes a sensor module  102 , a filter module  104 , and a biometrics module  106 . The various modules of the environment  100  may be embodied as hardware, firmware, software, or a combination thereof. For example the various modules, logic, and other components of the environment  100  may form a portion of, or otherwise be established by, the processor  20  or other hardware components of the controller  12 . As such, in some embodiments, any one or more of the modules of the environment  100  may be embodied as a circuit or collection of electrical devices (e.g., sensor circuitry, filter circuitry, biometrics circuitry, etc.). 
         [0029]    The sensor module  102  is configured to receive sensor data indicative of an occupant of the vehicle seat  14  from one or more vibration sensors  16  of the vehicle. As described above, the sensors  16  may include, for example, a piezoelectric sensor, an accelerometer, or a microphone. 
         [0030]    The filter module  104  is configured to determine a filter function in a biometric frequency range. The filter function identifies one or more frequencies of noise in the sensor data. For example, the filter function may include a notch filter at a resonant frequency of the vehicle seat  14  while occupied or at a transmission frequency of the vehicle. As another example, the filter function may include a notch filter at a frequency determined based on vehicle state data received from another controller  12  of the vehicle. The filter module  104  is further configured to apply the filter function to the sensor data to generate filtered sensor data. 
         [0031]    The biometrics module  106  is configured to determine biometric data associated with the occupant of the vehicle seat  14  based on the filtered sensor data. For example, the biometrics module  106  may be configured to determine a heart rate, a heart rate variability, or a respiration rate. 
         [0032]    Referring now to  FIG. 3 , in use, the controller  12  may execute a method  200  for determining biometric data of an occupant of the vehicle seat  14 . In some examples, the operations of the method  200  may be performed by one or more modules of the environment  100  of the controller  12  as shown in  FIG. 2 . The method  200  begins in block  202 , in which the controller  12  receives vibration sensor data from one or more sensors  16 . The vibration sensor data is indicative of vibrations caused by an occupant of the vehicle seat  14 . In some examples, in block  204  the controller  12  may receive sensor data from one or more piezoelectric sensors  16 . In some examples, in block  206  the controller  12  may receive sensor data from one or more accelerometers  16 . In some embodiments, in block  208  the controller  12  may receive sensor data from one or more microphones  16 . 
         [0033]    In block  210 , the controller  12  determines a filter function in a biometric frequency range. The biometric frequency range includes frequencies that may be used to determine biometric data of the occupant such as heart rate or respiration. The filter function may filter out one or more frequencies within the biometric frequency range that carry environmental noise, vehicle noise, are saturated, or otherwise interfere with biometric signals. For example, an impact, such as a pot hole, drives all frequencies. The suspension of the vehicle mutes the impact, reducing the amplitude and generating transmission frequency of the vehicle and drive dynamics (e.g., comfort or sports mode) sweeping and general noisy vibration will drive multiple frequencies. Engine vibrations are higher than this range, but similar to an impact tend to excite all frequencies in vibration. High energy engine vibrations may excite sub-harmonics in the range of transmission frequency of the vehicle seat. 
         [0034]    In block  212 , the controller  12  may determine a notch filter (i.e., a narrow band-reject filter) at a resonant frequency of the vehicle seat  14  while occupied. A vehicle seat  14 , like a tuning fork, may resonate when subjected to its natural frequency. Modal analysis determines the natural frequency response of a structure to an impact or excitation. When the vehicle seat  14  is subjected to vibrations from the vehicle at the seat&#39;s natural frequency, the vehicle seat  14  may respond, resonate, and transmit its natural frequencies. The transmissibility of the vehicle seat  14  while occupied is affected by the natural frequency of the vehicle seat  14 , as discussed above, as well as the addition of the occupant. The occupant adds mass, which tends to lower the frequency, adds structure which tends to raise the frequency, and adds damping, which generally reduces amplitude and broadens the band and/or bands of affected frequencies. The size, position, posture, and/or movement of the occupant may add further variation. 
         [0035]    In some embodiments, in block  214  the controller  12  may use a predetermined or otherwise static frequency for the notch filter at the resonant frequency of the occupied vehicle seat  14 . As described above, occupying the vehicle seat  14  may mute, lower, and/or broaden the frequency response of the unloaded vehicle seat  14 . The change in frequency response may depend on the size of the occupant (e.g., the weight, height, or other size metric of the occupant). In some embodiments, a predetermined frequency may be selected to treat the whole population of potential occupants equally by using percent improvement, which is the best filter percent performance minus no filter percent performance. In that embodiment, the most improvement would apply to the worst case and thus would emphasize outliers. Accordingly, this would result in the entire population achieving about the same result. Additionally or alternatively, in some embodiments a predetermined frequency may be selected based on a body type normal distribution. In that embodiment, the filter may be statistically weighted by body size, and the resulting filter function would be biased toward the 50th percentile body size. 
         [0036]    In some embodiments, in block  216  the controller  12  may determine the resonant frequency based on the size of the occupant (e.g., the occupant&#39;s height, weight, and/or other size metric). The controller  12  may adjust a base filter function based on the size of the occupant (e.g., muting, lowering, and/or broadening the frequency response as described above). For example, in some embodiments, the controller  12  may determine the size of the occupant based on user anthropometric information or other user profile information. The controller  12  may receive the anthropometric information, for example, from another controller  12  over the vehicle network  18  or via an input from the occupant. Additionally or alternatively, the controller  12  may determine the size of the user based on sensor data received from the sensors  16  and/or additional sensors of the vehicle. For example, the controller  12  may determine the weight of the user based on sensor data received from one or more load cells, strain gauges, or other weight sensors. 
         [0037]    In some embodiments, in block  218  the controller  12  may determine a notch filter for one or more frequencies of noise generated and/or transmitted by the vehicle. A vehicle is typically a noisy environment with multiple potential sources of vibration other than the sources of biometric data from an occupant. For example, vibration may come from the vehicle drivetrain (e.g., the engine transmission and the exhaust) and the road (e.g., suspension and vehicle dynamics.) Noise may also be produced by the vehicle acoustic environment (e.g., music and HVAC) and/or vehicle seat  14  features (e.g., adjustment, massage, vent, or other features). Actions of the occupant, such as speaking, movement, and/or posture may also affect vibration sensor readings. 
         [0038]    In some embodiments, in block  220  the controller  12  may determine the noise frequencies based on the model of the vehicle. Every vehicle model may have a particular transmission frequency. In some embodiments, in block  222  the controller  12  may determine the frequency of noise based on vehicle state. The controller  12  may receive the vehicle state data or other vehicle information from one or more other controllers  12  of the vehicle, such as an engine controller  12 . The vehicle state may indicate whether the vehicle is on or off, the speed of the engine (i.e., RPM), the engine load, the throttle position, the speed of the vehicle, or other attributes of the driving state of the vehicle. When characterized and associated with the transmission frequency of the vehicle model, the vehicle state information may be used to adopt an appropriate filter function. The engine may provide periodic excitation which the vehicle seat will transmit at the transmission frequency determined by the seat structure and the occupant size. This has been observed during idle and when the vehicle is freely decelerating. Thus, a notch filter may be used when the engine load indicates free deceleration, which may be determined as a function of engine RPM and vehicle speed. 
         [0039]    In block  224 , the controller  12  may adapt the filter function based on sensor data received from the sensors  16 . In some embodiments, in block  226  the controller  12  may characterize the noise in sensor data received from the sensors  16 . This can be derived from the transients of the sensors  16  themselves and/or other sensors. In some embodiments, the controller  12  may use a learning system that senses and characterizes noise. By sensing occupant size, weight, posture, and motion under different vehicle conditions (e.g., vehicle off, vehicle on, driving, pot hole impact, etc.), the controller  12  may characterize, learn, and adapt an appropriate filter regimen. 
         [0040]    After determining the filter function, in block  228 , the controller  12  applies the filter function to the sensor data to generate filtered sensor data. Thus, the controller  12  may remove environmental noise from the filtered sensor data. 
         [0041]    In block  230 , the controller  12  determines biometric data associated with the occupant based on the filtered sensor data. In particular, the controller  12  may analyze sensor data in the biometric frequency range. In some embodiments, in block  232  the controller  12  may determine the heart rate of the occupant. In some embodiments, in block  234  the controller  12  may determine heart rate variability of the occupant. The heart rate variability may be associated with alertness and stress level of the occupant. In block  236 , the controller  12  may determine the respiration rate of the occupant. After determining the biometric data, the method  200  loops back to block  202  to continue processing sensor data. The controller  12  may use the biometric data for biofeedback, to initiate therapy, or for other uses. Additionally or alternatively, although illustrated as executing sequentially, it should be understood that the operations of the method  200  may be performed in a different order and/or at different times. For example, in some embodiments, the filter function may be determined ahead of time prior to receiving the sensor data. 
         [0042]    Referring now to  FIG. 4 , chart  300  illustrates experimental results that may be achieved by the system  10 . The chart  300  illustrates the percent correlation to reference biometric data that is achieved by the system  10  as compared to the percent correlation achieved based on unfiltered sensor data. In the illustrative experimental results, the biometric data is occupant heart rate, and the reference data was generated directly using an electrocardiograph (ECG) harness. As shown, for a 93-kilogram occupant, the system  10  improves from about 62% to about 85% in the vehicle off state, from about 28% to about 93% in the idle state, from about 10% to about 84% in the run state, and from about 0% to about 95% in the free deceleration state. For an 88-kilogram occupant, the system  10  improves from about 45% to about 95% in the vehicle off state, from about 38% to about 82% in the idle state, from about 18% to about 73% in the run state, and from about 0% to about 52% in the free deceleration state. For an 80-kilogram occupant, the system  10  improves from about 87% to about 95% in the vehicle off state, from about 75% to about 78% in the idle state, from about 38% to about 73% in the run state, and from about 35% to about 100% in the free deceleration state. For a 49-kilogram occupant, the system  10  improves from about 45% to about 62% in the vehicle off state, from about 5% to about 80% in the idle state, from about 12% to about 60% in the run state, and from about 0% to about 100% in the free deceleration state.