Patent Grant
9478087
Embodiments of the subject matter described herein generally relate to vehicle systems, and more particularly relate to systems and methods for communicating between a vehicle and a remote device, such as an electronic key fob.
In recent years, advances in technology have led to substantial changes in the design of automobiles. For example, electronic key fobs are now ubiquitous and capable of communicating with the vehicle to allow the user to initiate any number of operations, such as, remote starting, remote locking/unlocking, or the like. More recently, automatic operations based on the proximity of a key fob are being incorporated into vehicles. However, these so-called “passive” features typically require the vehicle to continually monitor the surrounding environment for the presence of the key fob, which, in turn, continually consumes power from the battery or another energy source within the vehicle. Multiple communication modules may be co-located and integrated within a single vehicle component to reduce the energy consumption of the passive features. However, such integration often results in undesirable component sizes, decreased component packaging flexibility due to the transmission path characteristics of the communication frequencies utilized, and potentially increased costs. Accordingly, it is desirable to provide systems and methods for detecting the presence of the key fob with reduced power consumption without compromising the integration and packaging flexibility of the communication modules. Other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
In one of various exemplary embodiments, a method is provided for operating a first vehicle communications module that communicates with a remote device via a first communication channel. The method involves transmitting, by a second vehicle communications module via a second communication channel, an indication of an operating state of the first communications module, receiving, by the first communications module via the first communication channel, an acknowledgment responsive to the indication from the remote device, and changing the operating state of the first communications module in response to receiving the acknowledgment.
In another embodiment, an apparatus for a vehicle is provided. The vehicle includes a first communications module configured to communicate via a first communication channel and a second communications module configured to transmit an indication of a first operating state of the first communications module via a second communication channel. The first communications module is configured to transition from the first operating state to a second operating state in response to receiving an acknowledgment responsive to the indication from a remote device via the first communication channel.
According to another of various exemplary embodiments, an apparatus for a remote device suitable for use with an automotive vehicle is also provided. The remote device includes a first communications module configured to receive, via a first communication channel, an indication of an operating state of a vehicle communications module communicating via a second communication channel, and a second communications module configured to transmit a response to the indication via the second communication channel, wherein a duration of the response is influenced by the operating state of the vehicle communications module.
The exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Embodiments of the subject matter described herein relate to communications between a vehicle, such as an automobile, and a remote device associated with the vehicle, such as an electronic key fob. In exemplary embodiments, the vehicle includes a first communications module configured to communicate via a first communication channel and a second communications module configured to communicate via a second communication channel. For example, in one embodiment, the first communications module communicates via ultra-high frequency (UHF) communication channel and the second communications module communicates via a low frequency (LF) communication channel. Similarly, the remote device includes a communications module capable of communicating with the vehicle via a higher frequency (e.g., UHF) communication channel and a second communications module capable of communicating with the vehicle the lower frequency (e.g., LF) communication channel.
In exemplary embodiments, the vehicle higher frequency communications module operates in a lower power operating state (e.g., a sleep mode, an idle mode, or another low power operating mode) when the remote device is not within communications range of the vehicle. The vehicle lower frequency communications module periodically transmits an indication of the lower power operating state via the lower frequency communication channel. When the remote device is within the communications range of the vehicle, the remote device receives the indication of the lower power operating state and automatically transmits a response (or acknowledgment) via the higher frequency communication channel that has a duration that is influenced by the identified lower power operating state of the vehicle higher frequency communications module. The vehicle higher frequency communications module receives or otherwise detects the response and automatically transitions or otherwise changes from the lower power operating state to a higher power operating state (e.g., an active mode) to receive the entire content of the response. Thereafter, the content of the response is parsed or otherwise analyzed to authenticate that the source of the received response is the remote device that is associated or otherwise paired with the vehicle. In response to authenticating the remote device, operation of one or more vehicle subsystems may be automatically initiated to effectuate one or more “passive” features, such as, for example, passive lighting, passive/keyless entry, or the like.
Turning now to
Still referring to
In exemplary embodiments, the vehicle 102 is realized as an automobile, and depending on the embodiment, the vehicle 102 may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD). The vehicle 102 may also incorporate any one of, or combination of, a number of different types of engines, such as, for example, a gasoline or diesel fueled combustion engine, a “flex fuel vehicle” (FFV) engine (i.e., using a mixture of gasoline and alcohol), a gaseous compound (e.g., hydrogen and natural gas) fueled engine, a combustion/electric motor hybrid engine, and an electric motor. In alternative embodiments, the vehicle 102 may be a plug-in hybrid vehicle, a fully electric vehicle, a fuel cell vehicle (FCV), or another suitable alternative fuel vehicle. The energy source 108 (or power source) generally represents the component of the vehicle 102 that is capable of providing a direct current (DC) voltage (or current) for operating other components of the vehicle 102. For example, depending on the embodiment, the energy source 108 may be realized as a battery, a fuel cell, a rechargeable high-voltage battery pack, an ultracapacitor, or another suitable energy source known in the art. As illustrated in
As described in greater detail below, in exemplary embodiments, when the remote device 104 is outside the communications range 106 of the higher frequency communications module 110, the higher frequency communications module 110 is operated in an idle mode, a sleep mode, a low power mode, or the like to reduce the amount of power and/or current that is consumed by the higher frequency communications module 110 from an energy source 108 in the vehicle 102. In a lower power state, the vehicle higher frequency communications module 110 may periodically consume power and/or current from the energy source 108 for a relatively small percentage of a polling period. In one embodiment, the vehicle higher frequency communications module 110 periodically consumes power and/or current from the energy source 108 for less than ten percent of a polling period. For example, the polling period may be thirty milliseconds, where the vehicle higher frequency communications module 110 periodically consumes power and/or current for about three milliseconds.
While the higher frequency communications module 110 is in a lower power state, the lower frequency communications module 120 periodically broadcasts or otherwise transmits a query to determine which, if any, remote devices are present in proximity to the vehicle. Included within the query signal is an indication that the vehicle higher frequency communications module 110 is in the lower power state. When the remote device 104 is within the communications range of the lower frequency communications module 120, the remote device 104 receives the indication of the lower power state for the vehicle higher frequency communications module 110, and in response, automatically broadcasts or otherwise transmits a response or acknowledgment that is configured to change the operating state of the vehicle higher frequency communications module 110. The vehicle higher frequency communications module 110 receives the response and automatically transitions from the lower power state to a higher power state to support communications to/from the remote device 104 while the remote device 104 is within the communications range 106 of the vehicle higher frequency communications module 110. In some embodiments, the vehicle higher frequency communications module 110 continuously consumes power and/or current from the energy source 108 in the higher power state.
Referring now to
Still referring to
In exemplary embodiments, the vehicle lower frequency communications module 120 is realized as a transceiver or another suitable combination of baseband processing modules, radio frequency processing modules, multiplexers, mixers, modulators and/or demodulators, amplifiers, drivers, or the like, that is configured to support transmitting and receiving electromagnetic signals within a relatively lower frequency range (e.g., LF signals) via one or more antennas 170 in the vehicle 102. In the illustrated embodiments of
Still referring to
In the illustrated embodiments of
Referring now to
In exemplary embodiments, the remote device 104 is realized as an electronic key fob, however, the subject matter described herein is not limited to any particular type of remote device 104. In alternative embodiments, the remote device 104 may be realized as any sort of electronic device capable of communicating with the vehicle communications modules 110, 120, such as a mobile or cellular telephone, a laptop or notebook computer, a tablet computer, a desktop computer, a personal digital assistant, or the like. In yet other alternative embodiments, the remote device 104 could be realized as a garment, a piece of jewelry, or any other item that includes electronics capable of supporting the subject matter described herein. That said, electronic key fobs are commonly used to interact with vehicles, and accordingly, for purposes of explanation, but without limitation, the remote device 104 may alternatively be referred to herein as a key fob (or simply fob).
The energy source 302 generally represents the component of the key fob 104 that is coupled to the various modules 304, 306, 308 to provide a direct current (DC) voltage (or current) for operating the various modules 304, 306, 308 of the key fob 104. For example, in one or more embodiments, the energy source 302 is realized as a coin cell battery.
The control module 304 generally represents the hardware, processing logic, circuitry and/or a combination thereof that is coupled to the fob communications modules 306, 308 and configured to support communications with the vehicle 102 when the key fob 104 is within a vicinity of the vehicle 102. Depending on the embodiment, the control module 304 may be implemented or realized with a general purpose processor, a microprocessor, a controller, a microcontroller, a state machine, a content addressable memory, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. Furthermore, the steps of a method or algorithm described in connection with the embodiments described herein may be embodied directly in hardware, in firmware, in a software module executed by the control module 304, or in any practical combination thereof. In exemplary embodiments, the control module 304 includes or otherwise accesses a data storage element or memory, including any sort of random access memory (RAM), read only memory (ROM), flash memory, registers, hard disks, removable disks, magnetic or optical mass storage, or any other short or long term storage media or other non-transitory computer-readable medium, which is capable of storing programming instructions for execution by the control module 304. The computer-executable programming instructions, when read and executed by the control module 304, cause the control module 304 to perform various tasks, operations, functions, and processes described herein. In a similar manner as described above, in exemplary embodiments, the data storage element accessed by or otherwise integrated with the control module 304 stores or otherwise maintains a unique identifier associated with the vehicle 102 (e.g., a vehicle identification number or the like), thereby maintaining a pairing or association with the vehicle 102. The data storage element may also store or otherwise maintain the unique identifier associated with the remote device 104.
In a similar manner as described above in the context of the vehicle higher frequency communications module 110, in exemplary embodiments, the fob higher frequency communications module 306 is realized as a transceiver or another suitable combination of baseband processing modules, radio frequency processing modules, multiplexers, mixers, modulators and/or demodulators, amplifiers, drivers, or the like, that is configured to support transmitting and receiving electromagnetic signals within a relatively higher frequency range (e.g., UHF signals) via a higher frequency antenna 307 within the fob 104. Similarly, the fob lower frequency communications module 308 is realized as a transceiver or another suitable combination of baseband processing modules, radio frequency processing modules, multiplexers, mixers, modulators and/or demodulators, amplifiers, drivers, or the like, that is configured to support transmitting and receiving electromagnetic signals within a relatively lower frequency range (e.g., LF signals) via a lower frequency antenna 309 within the fob 104.
Still referring to
The illustrated detection process 400 initializes or otherwise begins by periodically obtaining or otherwise identifying the current operating state (or operating mode) for the vehicle higher frequency communications module at 402 and transmitting or otherwise broadcasting an indication of the current operating state of the vehicle higher frequency communications module via the vehicle lower frequency communications module at 404. In this regard, the control module 122 may periodically poll or otherwise monitor the vehicle higher frequency communications module 110 to assess or otherwise determine its current operating state. In accordance with one or more embodiments, the vehicle higher frequency communications module 110 communicates a flag or some other output bit that indicates its current operating state whenever it is in an active or on state, wherein the control module 122 periodically accesses the operating state flag bit to identify the current operating state. In this regard, control module 122 determines the higher frequency communications module 110 is in an idle, sleep, or off state in response to the absence of the status flag for more than a threshold period of time. For example, the vehicle higher frequency communications module 110 may assert a logic high signal (e.g., logic ‘1’) as the operating state flag bit when the vehicle higher frequency communications module 110 is in a higher power operating state and leave the output unasserted (e.g., logic ‘0’) when the vehicle higher frequency communications module 110 is in a lower power operating state. In another embodiment, communications module 110 and control module 122 are coupled or otherwise connected with an in-vehicle communication network such as a Controller Area Network (CAN) or Local Interconnect Network (LIN), and operating state commands and status may be signals communicated within the network.
After obtaining the current status of the vehicle higher frequency communications module 110, the control module 122 generates a query message for transmission via the lower frequency communications module 120, wherein the query message indicates the current operating state of the higher frequency communications module 110. In exemplary embodiments, the query message generated by the control module 122 also includes the unique identifier associated with the vehicle 102 along with a value that may be utilized to authenticate responses to the query message. For example, the control module 122 may include a random number generator or the like that generates an acknowledgment value that may be included in the query message. In addition to and/or in conjunction with the unique identifier associated with the vehicle 102, the query message may include a pattern or sequence of bits configured to wake up, enable, or otherwise activate the fob 104, as described in greater detail below. After generating the query message, the control module 122 operates the vehicle lower frequency communications module 120 to transmit or otherwise broadcast the status message via a lower frequency communication channel. For example, the control module 122 may activate, enable, or otherwise turn on the vehicle lower frequency communications module 120 for a duration of time required to transmit the status message before reverting the vehicle lower frequency communications module 120 to a lower power state (e.g., an idle mode, a sleep mode, or the like) during which the vehicle lower frequency communications module 120 does not consume power from the energy source 108.
In exemplary embodiments, the detection process 400 continues by determining or otherwise identifying whether or not the associated remote device is within communications range of the vehicle higher frequency communications module at block 406 and operates the vehicle higher frequency communications module in a lower power state at block 408 when the remote device is not within communications range of the vehicle higher frequency communications module. In the lower power state (e.g., an idle operating mode, a sleep mode, or the like) the vehicle higher frequency communications module 110 periodically consumes power from the energy source 108 to periodically activate and listen for acknowledgment messages from the fob 104 before reverting to an inactive state where the vehicle higher frequency communications module 110 does not consume as much power from the energy source 108 for the remaining duration of the periodic interval. As described below, when the fob 104 receives a status message transmitted via the vehicle lower frequency communications module 120, the fob 104 automatically transmits an acknowledgment message via its higher frequency communications module 306 that is capable of being received by the vehicle higher frequency communications module 110.
In the absence of receiving the response to the status message from the fob 104, the vehicle higher frequency communications module 110 may automatically be operated in the lower power operating state. For example, in some embodiments, the vehicle higher frequency communications module 110 may implement a timer or some other equivalent feature so that if more than a specified time period has elapsed since the most recent acknowledgment message while the higher frequency communications module 110 is in an active operating mode where power from the energy source 108 is continuously consumed, the higher frequency communications module 110 may automatically transition from the active operating mode to an idle operating mode where power from the energy source 108 is periodically consumed. In other embodiments, the control module 122 may signal, command, or otherwise operate the vehicle higher frequency communications module 110 in the lower power state. For example, in the absence of an acknowledgment message, the control module 122 may automatically signal, command or otherwise operate the vehicle higher frequency communications module 110 to transition the vehicle higher frequency communications module 110 from the higher power operating state to the lower power operating state. In exemplary embodiments, the loop defined by 402, 404, 406 and 408 repeats so that the current operating status of the vehicle higher frequency communications module 110 is periodically obtained, the vehicle lower frequency communications module 120 is periodically activated to periodically transmit the indication of the current operating status of the vehicle higher frequency communications module 110, and the vehicle higher frequency communications module 110 is maintained in a lower power operating state while the fob 104 is not within communications range 106.
In response to determining or otherwise identifying that associated remote device is within communications range of the vehicle higher frequency communications module at block 406, the detection process 400 continues by operating the vehicle higher frequency communications module in a higher power state at block 410. In this regard, when the vehicle higher frequency communications module 110 is in the lower power state and receives a response to the indication previously transmitted via the vehicle lower frequency communications module 120, the vehicle higher frequency communications module 110 is automatically transitioned from the lower power operating state to a higher power operating state where the vehicle higher frequency communications module 110 continuously monitors the higher frequency communication channel for command signals from the fob 104. For example, as described in greater detail below, an acknowledgment message responsive to the indication may include a header portion having a duration greater than the periodic polling period of the vehicle higher frequency communications module 110 to ensure that the vehicle higher frequency communications module 110 receives or otherwise detects the acknowledgment message. In response, the vehicle higher frequency communications module 110 automatically transitions to an active operating mode to support receiving the entirety of the acknowledgment message transmitted by the fob 104 along with any other subsequent command signals that may be transmitted by the fob 104 while the fob 104 is within range 106.
In the illustrated embodiment, the detection process 400 continues by authenticating or otherwise verifying that the source of the response is a remote device associated with the vehicle at 412 and automatically initiates operation of one or more vehicle subsystems in response to authenticating the remote device at 414. In exemplary embodiments, the acknowledgment message received by the vehicle higher frequency communications module 110 is provided to the control module 122, which, in turn, parses or otherwise analyzes the content of the acknowledgment message to confirm the source of the acknowledgment message is the fob 104 that is paired or otherwise associated with the vehicle 102. As described in greater detail below in the context of
When the received fob identification number matches the fob identification number from the status message and the received acknowledgment value matches the acknowledgment value from the status message, the control module 122 authenticates the response as being from the fob 104 paired with the vehicle 102. In accordance with one or more embodiments, the control module 122 automatically operates one or more vehicle subsystems 202 in response to detecting the fob 104 within the vicinity of the vehicle 102. In such embodiments, in response to authenticating a received acknowledgment message as being from the fob 104 associated with the vehicle 102, the control module 122 may automatically initiate operation of one or more vehicle subsystems 202, for example, by generating and providing the appropriate commands or signals to those vehicle subsystems 202. For example, if a passive lighting feature is enabled on the vehicle 102, the control module 122 may automatically command the lighting system 202 to activate or otherwise turn on one or more of the headlights, taillights, parking lights, brake lights, directional indicators, or the like.
Additionally, the control module 122 may operate one or more vehicle subsystems 202 in response to receiving user-initiated commands from the fob 104 while the fob 104 is within range 106 of the vehicle 102. For example, a user may manipulate a user input element 310 to open one or more doors 160 of the vehicle 102, wherein in response to the user manipulating the user input element 310, the control module 304 automatically generates corresponding door-opening commands and operates the higher frequency communications module 306 to transmit or otherwise communicate the door-opening commands to the vehicle 102. By virtue of the vehicle higher frequency communications module 110 being in the active operating mode once the fob 104 is within range 106 of the vehicle 102, the door-opening commands are received by the vehicle higher frequency communications module 110 and provided to the control module 122, which, in turn, may automatically operate the entry system 202 of the vehicle 102 accordingly to initiate the action commanded by the user operating the fob 104 in response to receiving the command.
In exemplary embodiments, the loop defined by 402, 404, 406, 408, 410 and 412 repeats so that the current operating status of the vehicle higher frequency communications module 110 is periodically obtained and the vehicle lower frequency communications module 120 is periodically activated to periodically transmit the indication of the current operating status of the vehicle higher frequency communications module 110. In this regard, as described in greater detail below, in response to receiving a status message indicating the vehicle higher frequency communications module 110 is in the higher power operating state, the fob 104 automatically transmits a response or acknowledgment message via its higher frequency communications module 306 that maintains the vehicle higher frequency communications module 110 in the higher power operating state throughout the duration of time the fob 104 is within the range 106 of the vehicle 102. Once the fob 104 is outside the range 106 of the vehicle 102, the fob 104 does not receive the status messages transmitted by the vehicle lower frequency communications module 120, and therefore, does not transmit acknowledgment messages to the vehicle 102. In response to an absence of a response to the indication of the operating state of the vehicle higher frequency communications module 110, the vehicle higher frequency communications module 110 and/or the control module 122 automatically transition the vehicle higher frequency communications module 110 from the higher power operating state to the lower power operating state to conserve power once the fob 104 is outside the communications range 106.
In exemplary embodiments, the acknowledgment process 500 identifies, detects or otherwise determines whether a message configured to activate or otherwise wakeup the remote device has been received via the lower frequency communications module of the remote device at 502. In this regard, in exemplary embodiments, the control module 304 and the fob higher frequency communications module 306 are both operated in a lower power operating mode (e.g., a sleep mode, an idle mode, or the like) to conserve power consumed from the energy source 302 in the absence of receiving messages from the vehicle 102 via the fob lower frequency communications module 308 that identify fob 104. When the fob 104 is within the communications range of the vehicle lower frequency communications module 120, the fob lower frequency communications module 308 receives the periodic query messages transmitted by the vehicle 102 that include the unique identifier for the vehicle 102 associated with the fob 104 and/or a pattern or sequence of bits configured to wake up, enable, or otherwise activate the fob 104. In response to receiving the status message including the unique vehicle identification number and/or the wakeup pattern, the control module 304 transitions from the lower power operating mode to a higher power operating mode (e.g., an active mode) and signals, commands or otherwise operates the fob higher frequency communications module 306 to transition the fob higher frequency communications module 306 from the lower power operating state to a higher power operating state.
After receiving a message configured to activate or otherwise enable the higher frequency communications of the remote device at 502, the acknowledgment process 500 continues by identifying or otherwise determining the operating status of the vehicle higher frequency communications module at 504, generating or otherwise creating an acknowledgment message based on the identified operating status at 506, and transmitting or otherwise broadcasting the acknowledgment message to the vehicle via the higher frequency communication channel at 508. The control module 304 parses or otherwise analyzes the status message received from the vehicle 102 to identify the operating state of the vehicle higher frequency communications module 110, and based on the indicated operating state, constructs an acknowledgment message having a length that is dependent on the indicated operating status for the vehicle higher frequency communications module 110. In this regard, when the status message indicates the vehicle higher frequency communications module 110 in a lower power state, the control module 304 and/or fob 104 generates a long acknowledgment message having a duration of transmission that is greater than the duration between the periodic polling by the vehicle higher frequency communications module 110 in the low power state. For example, if the vehicle higher frequency communications module 110 periodically polls for an acknowledgment message every forty milliseconds in an idle mode, the control module 304 and/or fob 104 generates a long acknowledgment message having a header (or preamble) portion including a number of bits such that a transmission duration for the header portion is greater than forty milliseconds, thereby ensuring that the vehicle higher frequency communications module 110 will detect the acknowledgment message while in the idle mode. Conversely, when the status message indicates the vehicle higher frequency communications module 110 in a higher power state, the control module 304 and/or fob 104 generates a short acknowledgment message having a header portion that contains a reduced number of bits relative to the long acknowledgement message.
For example, referring now to
Referring again to
After transmitting the acknowledgment message, the illustrated acknowledgment process 500 continues with the remote device automatically transitioning or otherwise reverting back to a lower power operating state at 510. In exemplary embodiments, after operating the higher frequency communications module 306 to transmit the acknowledgment message, the control module 304 and the higher frequency communications module 306 automatically transition back from an active mode to an idle or sleep mode to conserve power consumed from the energy source 302. In this manner, when the fob 104 leaves or otherwise exits the communications range 106 of the vehicle 102, the control module 304 and the higher frequency communications module 306 may automatically operate in a lower power mode by default. In practice, the acknowledgment process 500 repeats indefinitely in response to the fob 104 detecting or otherwise receiving messages via its lower frequency communications module 308 to receive and acknowledge any messages transmitted by its associated vehicle 102.
In the illustrated example, at some subsequent time (t1), the fob 104 enters the communications range 106 of the vehicle 102, so that the lower frequency communications module 308 of the fob 104 receives the periodic query message 802 transmitted via a lower frequency communication channel by the vehicle lower frequency communications module 120 at the beginning of the next status message transmission period at time (t2). In response to detecting a query message 802 identifying the vehicle 102 associated with the fob 104 as the source of the query message 802, the control module 304 and the fob higher frequency communications module 306 transition from a lower power state to a higher power state. Based on the query message 802 indicating that the vehicle higher frequency communications module 110 is in a lower power operating state, the control module 304 generates a long acknowledgment message 600 and transmits the long acknowledgment message via the fob higher frequency communications module 306. As illustrated, the transmission duration (tD) of the long acknowledgment message 600 is greater than the duration of the periodic polling period (tP) for the vehicle higher frequency communications module 110 in the lower power operating state, such that the vehicle higher frequency communications module 110 detects the long acknowledgment message 600 at the beginning of the next polling period at time (t3) and transitions to a higher power operating state.
At the beginning of the next query message transmission period at time (t4), the control module 122 identifies or otherwise determines the current operating state of the vehicle higher frequency communications module 110 as the higher power operating state and transmits a query message 804 via the vehicle lower frequency communications module 120 that indicates the vehicle higher frequency communications module 110 is in the higher power operating state. In response, to a query message 804 identifying the higher frequency communications module 110 of the associated vehicle 102 is in the higher power operating state, the control module 304 generates a short acknowledgment message 700 and transmits the long acknowledgment message via the fob higher frequency communications module 306. In response to the short acknowledgment message 700, the higher frequency communications module 110 is maintained in the higher power operating state throughout the duration of time the fob 104 is within communications range 106 of the vehicle 102 to ensure any user-initiated commands (e.g., via user input element 310) can be received by the higher frequency communications module 110. As described above, once the fob 104 is no longer within the communications range 106 of the vehicle and stops receiving the query messages 804, the fob 104 ceases transmitting acknowledgment messages, which, in turn, causes the higher power operation of the higher frequency communications module 110 to timeout such that the higher frequency communications module 110 reverts to the lower power operating state. In this manner, when an associated fob 104 is within communications range 106 of the vehicle 102, the vehicle higher frequency communications module 110 is operated in an active operating mode to facilitate receiving user-initiated commands from the fob 104. Conversely, when the associated fob 104 is not within communications range 106 of the vehicle 102, the vehicle higher frequency communications module 110 may be operated in an idle (or sleep) mode to conserve power. In one or more embodiments, the higher frequency communications module 110 may automatically transition to the lower power operating state when a threshold amount of time has elapsed since an acknowledgment message was last received (e.g., after 100 milliseconds have passed since the last acknowledgment message). In other embodiments, the higher frequency communications module 110 may automatically transition to the lower power operating state only when other criteria are satisfied (e.g., some activity by or with respect to one or more vehicle subsystems 202, the vehicle 102 or another component therein may prevent the higher frequency communications module 110 from transitioning to the lower power operating state until that activity has ceased).
One benefit of the subject matter described herein is that the power consumption for detecting the presence of a remote device in the vicinity of a vehicle may be reduced. Additionally, the higher frequency communications module in the vehicle may be packaged separately from the lower frequency communications module to improve performance of the higher frequency communications module by moving it away from potential sources of electromagnetic interference. The vehicle communications modules are also capable of operating asynchronously, thereby reducing complexity.
For the sake of brevity, conventional techniques related to radio frequency communications, signaling, and other functional aspects of the subject matter may not be described in detail herein. In addition, certain terminology may also be used herein for the purpose of reference only, and thus are not intended to be limiting. For example, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. Additionally, the foregoing description also refers to elements or nodes or features being “connected” or “coupled” together. As used herein, unless expressly stated otherwise, “connected” means that one element is directly joined to (or directly communicates with) another element, and not necessarily mechanically. Likewise, unless expressly stated otherwise, “coupled” means that one element is directly or indirectly joined to (or directly or indirectly communicates with) another element, and not necessarily mechanically. Thus, although a schematic shown in the figures may depict direct electrical connections between circuit elements and/or terminals, alternative embodiments may employ intervening circuit elements and/or components while functioning in a substantially similar manner.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof. Accordingly, details of the exemplary embodiments or other limitations described above should not be read into the claims absent a clear intention to the contrary.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6538560 | Stobbe | Mar 2003 | B1 |
| 20020017978 | Kanda | Feb 2002 | A1 |
| 20100245038 | Ghabra | Sep 2010 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20150077225 A1 | Mar 2015 | US |
