Patent ID: 12257977

DETAILED DESCRIPTION

A vehicle access system1comprising an access control device2in accordance with an embodiment of the present invention will now be described. As shown inFIG.1, the vehicle access system1is configured to provide remote control of one or more functions of a vehicle3. Exemplary functions that may be controlled include, but are not limited to, enhanced Passive Entry and Passive Start (ePEPS) keyless access, remote engine start, remote opening and closing of vehicle apertures, deployment and retraction of external mirrors, a tow-bar or antennas, remote raising or lowering of side windows, remote opening or closing of a sunroof, remote opening or closing of a tailgate, remote activation of a vehicle powertrain, remote activation of a vehicle heating ventilation and air conditioning (HVAC) system, and/or activation and deactivation of lighting and signalling systems of the vehicle3.

The vehicle3in the present embodiment is an automobile, but the vehicle access system1may be implemented in other types of vehicle. The vehicle3has a front right door4, a rear right door5, a front left door6and a rear left door7. The vehicle3also has a boot lid (also known as a deck lid or trunk lid) which can be locked/unlocked by the vehicle access system1but this is not described herein. The front and rear doors4to7each comprise a locking mechanism. The locking mechanisms each comprise a lock actuator operable to lock and unlock a mechanical lock. The front doors4,6each have a folding door mirror incorporating a mirror actuator for folding and unfolding the door mirrors. The vehicle3optionally comprises a positioning system8, such as a Global Navigation Satellite System (GNSS), for example, Global Positioning System (GPS), to receive a position signal SLOC indicating a current (i.e. real time) geospatial position of the vehicle3. Other techniques may be used to determine the geospatial position of the vehicle3, for example by wireless communication with one or more nodes of a cellular communication network (either directly from a wireless transceiver disposed in the vehicle3, or via a cellular telephone paired to the vehicle3).

The vehicle access system1comprises a base station10which is operatively installed in the vehicle3to provide a Remote Function Actuator (RFA). The base station10comprises a first electronic control unit11and a first rechargeable battery12. The first electronic control unit11comprises a first memory storage device13in communication with a first processor14. The first processor14is configured to execute computational instructions stored in the first memory storage device13. The first rechargeable battery12provides a dedicated power supply for the base station10to enable its operation independently of a vehicle power system (not shown). The base station10comprises first, second and third ultra-wideband transceivers15,16,17. The relative position of the transceivers15,16,17in the vehicle3are defined. In the present embodiment, the first transceiver15is located at the rear of the vehicle3and the second and third transceivers16,17are located in the upper part of the vehicle3(typically in the roof) on the right and left sides respectively of the vehicle3. The first, second and third transceivers15,16,17are connected to the first electronic control unit11via a communication network, such as a dedicated local interconnect network (LIN). The transceivers15,16,17each comprise an antenna.

The base station10is connected to a plurality of vehicle systems18-1,18-2etc. (referred to collectively herein as18-n) via a communication network19, such as a CAN bus. The vehicle systems18-nmay, for example, comprise the door locking mechanisms and/or the folding door mirrors described herein. Alternatively, or in addition, the vehicle systems18-nmay include one or more of the following: closure systems for vehicle apertures, such as a door windows, a sun roof, a deck lid, a bonnet (hood); a ventilation system; engine start/ignition; a vehicle lighting (internal and/or external); entertainment systems; horn; heater; air conditioning; a deployable tow-bar; security systems, such as an alarm system and/or a vehicle immobilizer; etc. The base station10is operable to receive a status signal from each vehicle system18-n(for example, to indicate a current state of the door locking mechanisms; and/or to indicate a current position of the folding door mirrors); and to output a control signals to each vehicle system18-nto control operation thereof (for example to operate the lock actuators to lock or unlock the door locking mechanisms; and/or to operate the mirror actuators to fold or unfold the folding door mirrors). The communication network19can also be employed to convey instructions from the first electronic control unit11to other systems (e.g., actuators, system controllers and control units) of the vehicle3, such as a powertrain control unit, to facilitate enabling and/or disabling of one or more vehicle systems (e.g., passive engine starting).

The access control device2is a portable device, typically in the form of a handheld device. The access control device2in the present embodiment is in the form of a key fob, but could be incorporated into a cellular telephone or a portable computational device. As described herein, the access control device2communicates with the base station10to control the vehicle systems18-n, for example to unlock the door mechanisms to provide passive entry to the vehicle3. As shown schematically inFIG.2, the access control device2comprises a second electronic control unit20, a remote ultra-wideband transceiver21and a second battery22. The second electronic control unit20comprises a second memory storage device23in communication with a second processor24. The second battery22provides a dedicated power supply for the access control device2. The second battery22in the present embodiment is a rechargeable battery which may, for example, be charged when the access control device2is connected to the base station10. As described herein, the second electronic control unit20is configured to control operation of the access control device2. The second processor24is configured to execute computational instructions stored in the second memory storage device23. The second processor24may optionally be configured to implement a clock function to determine a time of day. The access control device2also comprises a movement sensor30, such as an accelerometer, for detecting movement of the access control device2.

The first, second and third transceivers15,16,17provided on the vehicle3are operable to communicate with the access control device2. The distance from each of the first, second and third transceivers15,16,17to the remote transceiver21can be determined by measuring transmission and/or response times (for example, time of flight for a signal transmission). Since the relative positions of the first, second and third transceivers15,16,17on the vehicle3are known, the position of the access control device2in relation to the vehicle3can be determined through triangulation. The use of ultra-wideband frequencies (typically greater than 3 GHz) allows the position of the access control device2to be tracked with a relatively high degree of accuracy. The determination of the position of the access control device2relative to the vehicle3can be performed by the first electronic control unit11provided in the base station10; and/or the second electronic control unit20provided in the access control device2. In the present embodiment, the second electronic control unit20is configured to determine the position of the access control device2relative to the vehicle3. A geospatial position of the vehicle3may be known, for example from the positioning system8. The second electronic control unit20may use the known geospatial position of the vehicle3to estimate the geospatial position of the access control device2. In a variant, the access control device2may comprise a positioning system operable to determine the geospatial position of the access control device2.

The second electronic control unit20is selectively operable in a first operating mode P1 and a second operating mode P2. The first operating mode P1 may be a limited response mode in which the access control device consumes less power. The limited response mode may, for example, be one of the following: a “sleep” mode (i.e. completely inactive for a period of time); a limited response duty cycle mode (inactive for a long period of time), or periodically active for a short period of time. The first operating mode P1 is a low-power mode in the present embodiment. The second electronic control unit20may disable or suppress selected control functions or features when operating in the first operating mode P1. For example, the second electronic control unit20may reduce or inhibit communication with the base station10when operating in the first operating mode P1. As described herein, the access control device2is configured to activate the first operating mode P1 to conserve power in the second battery22. The second operating mode P2 may be activated when movement of the access control device2is detected, and/or the access control device2is actuated. The actuation of the access control device2comprises operating the access control device2. The actuation of the access control device2may, for example, comprise a user pressing a button on the access control device2(such as a LOCK/UNLOCK button) and/or moving the access control device2to perform a gesture. The operation of the second electronic control unit20to control switching between said first and second operating modes P1 and P2 will now be described.

The applicant has recognized that a user may habitually leave the access control device2in the same position when it is not in use. For example, upon returning home from work in the evening, a user may leave the access control device2on the same shelf or in the same drawer. The second electronic control unit20is configured to identify when the access control device2is located in a position where expected usage of the access control device2is low. The expected usage of the access control device2may, for example, be predicted in dependence on historic usage of the access control device2in a particular position. As illustrated inFIG.3, one or more designated area A1 is defined to identify a geospatial position (or geospatial positions) where expected usage of the access control device2is low. The designated area A1 may, for example, correspond to a position where the access control device2is stored when not in use, for example a position where the access control device2is left overnight or for extended periods of time during the day. The designated area A1 may define a specific geospatial position or a geospatial area. It will be understood that the one or more designated area A1 is typically unique for any given access control device2.

As described herein, the second electronic control unit20determines the position of the access control device2relative to the vehicle3. The second electronic control unit20is configured to determine when the access control device2is positioned within the designated area A1. Upon determining that the access control device2is positioned within the designated area A1, the second electronic control unit20may be configured to generate a control signal S1to activate the first operating mode P1. The first operating mode P1 may be activated automatically when the second electronic control unit20determines that the access control device2is located in the designated area A1. However, this control strategy may result in erroneous activation of the first operating mode P1, for example if the access control device2is transported through the designated area A1.

In order to reduce or avoid unnecessary switching between the first and second operating modes P1, P2, the second electronic control unit20is configured to activate the first operating mode P1 upon determining that the access control device2has been stationary (immobile) for a predetermined period of time. The position of the access control device2remains substantially unchanged when it is stationary. The second electronic control unit20may determine that the access control device2is stationary by communicating with the base station10to identify changes in position relative to the vehicle3. Alternatively, or in addition, the movement sensor30may determine when the access control device2is stationary. The second electronic control unit20is configured to implement a timer module for monitoring a time period that the access control device2is stationary. In a further variant, the base station10may monitor the position of the access control device2to identify when the access control device2is stationary.

The second electronic control unit20is configured to output the control signal S1to activate the first operating mode P1 when the access control device2is identified as being dormant (or inactive). The second electronic control unit20characterizes the access control device2as being dormant when it is has been stationary for a predetermined period of time (referred to herein as a “dormant time t(DOR)”). The dormant time t(DOR)may be controlled dynamically in dependence on the position of the access control device2. The second electronic control unit20may be configured to reduce the dormant time t(DOR)when the access control device is in the designated area A1. When the access control device2is positioned inside the designated area A1, the second electronic control unit20outputs the control signal S1when the access control device2is stationary for a first dormant time t1(DOR). When the access control device2is positioned outside the designated area A1, the second electronic control unit20outputs the control signal S1when the access control device2is stationary for a second dormant time t2(DOR). The first dormant time t1(DOR)is less than the second dormant time t2(DOR), such that the first operating mode P1 is activated more quickly when the access control device2is positioned inside the designated area A1. The dormant time t(DOR)may be proportional to a historic usage of the access control device2in a given position. The implementation of a dormant time t(DOR)which is determined dynamically in dependence on the position of the access control device2may be used independently of, or in conjunction with, the designated area A1.

The access control device2may be configured to communicate with the positioning system8to download any stored positions or addresses into the second memory storage device23. The access control device2may use a stored position or address to identify a designated area A1 where the access control device2is likely to be dormant for an extended period of time. By way of example, the user may set a home position and/or a work position using the positioning system8in the vehicle3. The home position and/or the work position are used to identify designated areas where the access control device2is likely to be dormant for an extended period of time. The vehicle access system1may be arranged to communicate with the positioning system8, and upon determining that the vehicle has arrived at a stored position or address, such as the predefined home position and/or the work position, send a signal to the access control device2to provide a notification that the access control device2is likely to be dormant for an extended period of time following locking of the vehicle3. At least in certain embodiments, this arrangement provides the benefit of reducing power consumption and also reducing storage requirements in the second memory storage device23.

In a variant, the base station10may monitor the position of the access control device2and identify when the access control device2has been stationary (immobile) for a predetermined time period inside the designated area A1. In this iteration, upon determining that the access control device2has been stationary for the predetermined time period inside the designated area A1, the base station10may transmit a notification signal to the access control device2to activate the first operating mode P1.

In a further variant, the second electronic control unit20is configured to characterise the access control device2as being dormant when it is not actuated by a user for the predetermined dormant time t(DOR). When determining whether the access control device2is dormant, the second electronic control unit20may optionally also monitor movement to identify when the access control device is stationary (i.e. immobile). For example, the second electronic control unit20may identify the access control device2as being dormant when it has not been actuated and has remained stationary for the predetermined dormant time. The dormant time t(DOR)may be controlled dynamically in dependence on the position of the access control device2. The second electronic control unit20is configured to reduce the predetermined dormant time t(DOR)when the access control device2is in the designated area A1. When the access control device2is positioned outside the designated area A1, the second electronic control unit20outputs the control signal S1when the access control device2is stationary for the first dormant time t1(DOR). When the access control device2is positioned inside the designated area A1, the second electronic control unit20outputs the control signal S1when the access control device2is stationary for a second dormant time t2(DOR). The second dormant time t2(DOR)is less than the first dormant time t1(DOR), such that the first operating mode P1 is activated more quickly when the access control device2is located in the designated area A1. The second dormant time t2(DOR)may, for example, be one (1) or two (2) seconds. The first dormant time t1(DOR)is significantly longer and may be as long as one (1) or more minutes. The dormant time t(DOR)may be proportional to a historic usage of the access control device2in a given position.

The designated area A1 could be user defined. For example, the user may specify one or more “home” position for the access control device2which can be defined as the designated area A1. In the present embodiment, the second electronic control unit20is configured automatically to identify one or more designated area A1. The second electronic control unit20is configured to monitor actuation of the access control device2to determine an actuation rate of the access control device at a given position. The second electronic control unit20can identify one or more position where the actuation rate of the access control device2is below a predefined actuation threshold. The actuation threshold may, for example, correspond to actuation of the access control device2less than one (1) time for every ten (10) hours. The second electronic control unit20may be configured to identify any position where the actuation rate is below the predefined actuation threshold on a plurality of separate occasions, for example to identify a position where the actuation rate is below the predefined actuation threshold on at least five (5) or ten (10) separate occasions. The second electronic control unit20may define any such positions as being a designated area A1. The second electronic control unit20can optionally be configured to identify a position where the access control device2remains stationary for a period of time longer than a predetermined time threshold. The time threshold may, for example, be defined as four (4) or eight (8) hours. Other values for time thresholds are useful and may be selected from a number of different thresholds, each associated with one or more of the following: a time of day, a day of the week and/or a position. The designated area A1 may be identified as a position where the access control device2remains at least substantially stationary for a period of time greater than the time threshold. In a variant the first electronic control unit11may monitor the usage and/or the position of the access control device2to identify the designated area A1. In such a variant, the base station10could be configured to transmit a notification signal to the access control device2to indicate when the access control device2is positioned within a designated area A1. Alternatively, the base station10may be configured to transmit the control signal S1to activate the first operating mode P1.

The operation of the vehicle access system1is illustrated inFIGS.4A,4B and4C. The access control device2is initially in the second operating mode P2. The acceleration of the access control device2(as measured by the movement sensor30) is illustrated inFIG.4A. In the time period t0 to t1, the access control device2is being carried by a user and the resulting movements are detected by the movement sensor30. At time t1, the access control device2is stationary, for example the access control device2is placed on a table. The second electronic control unit20detects the uniform acceleration and identifies that the access control device2is stationary. A timer is started to measure the dormant time t1(DOR). The activation of the first operating mode P1 is dependent on the determined position of the access control device2. As shown inFIG.4B, if the access control device2is identified as being inside the designated area A1, the second processor24is configured to output the control signal S1to activate the first operating mode P1 upon determining that the access control device2has remained stationary for a second dormant time t2(DOR). As shown inFIG.4C, if the access control device2is identified as being outside the designated area A1, the second processor24is configured to output the control signal S1to activate the first operating mode P1 upon determining that the access control device2has remained stationary for a first dormant time t1(DOR). The second dormant time t2(DOR)is less than the first dormant time t1(DOR), as represented by the symbol Δt inFIG.4B. Thus, the activation of the first operating mode P1 occurs more quickly when the access control device2is located in the designated area A1. In this way, energy may be conserved by the access control device2and the useful life of the energy storage means, such as the second battery22, is increased.

The designated area A1 may be defined as a positional offset relative to a predefined position. The positional offset may be a result of inherent inaccuracies in determining the position of the access control device2. Alternatively, the positional offset may be defined relative to a known position of the access control device2. For example, the designated area A1 may be defined as ±x metre(s) relative to the predefined position, where x is greater than or equal to one (1) metre, two (2) metres or five (5) metres. Other values of x may usefully be defined to define different positional offsets.

It will be appreciated that various modifications may be made to the embodiment(s) described herein without departing from the scope of the appended claims.

The second electronic control unit20may be configured to identify the designated area(s) A1 by identifying one or more position where the access control device2switches from the second operating mode P2 to the first operating mode P1 on a predetermined number of occasions. For example, if the second electronic control unit20determines that the access control device2has switched from the second operating mode P2 to the first operating mode P1 at the same position on a plurality of separate occasions, this position may be used to define the designated area A1.

The vehicle access system1has been described herein as determining an absolute geospatial position of the access control device2in order to control activation of the first operating mode P1. In this arrangement, the designated area A1 is also defined in absolute terms. In a variant, the designated area A1 may merely be defined in relation to the vehicle3, for example a particular heading and/or distance from the vehicle3. The determination of the relative position of the access control device2relative to the vehicle3is illustrated inFIG.3by X and Y coordinates. By monitoring the position of the access control device2relative to the vehicle3, the first electronic control unit11or the second electronic control unit20may determine when the access control device2is located in the designated area A1.

In a further development, the first electronic control unit11or the second electronic control unit20may track a path or movement route of the access control device2to identify when expected usage is low. This technique may be applicable if the user follows an identifiable route from the vehicle3into their home or place of work where the access control device2will be stored. The tracking of the path or movement route may be performed in addition to, or instead of, the techniques described herein to determine when the access control device2is located in a designated area A1.

It has been recognized also that there may be a consistency in the time of day when the user is less likely to use the access control device2. In a further development, the second electronic control unit20may be configured to generate the control signal S1in dependence on a time of day and/or a day of the week.