Multi-sensor passive keyless functionality
In selected examples, a vehicle control system (VCS) includes Bluetooth beacons and an app running on a mobile device, such as a smartphone or a key fob equipped with movement sensors and a Bluetooth® transceiver. Passive keyless entry capability of the system uses received signal strength indications (RSSIs) together with movement-related indications of the movement sensors to determine when the mobile device moves away from the vehicle beyond a predetermined departure distance, and/or approaches the vehicle to within a predetermined arrival distance. When the user approaches the vehicle, the mobile device automatically transmits an arrival notification to the VCS, which automatically performs arrival actions, e.g., unlocking doors and disarming security features of the VCS/vehicle. When the user moves away from the vehicle, the mobile device automatically transmits a departures notification to the VCS, which performs departure actions, e.g., locking the vehicle and arming the security features of the VCS/vehicle.
1 . A method of automatic passive action operation, the method comprising steps of:
obtaining received signal strength indications (RSSIs) of transmissions by a processor of a mobile device from a relatively-short range radio frequency (RF) transceiver of the mobile device that receives the transmissions, the transmissions being transmitted by an asset-installed system, the asset-installed system being installed in a vehicle;
obtaining one or more movement-related indications that are different than the RSSIs by the processor from one or more movement sensors of the mobile device, the movement-related indications indicating movement or lack of movement of the mobile device;
obtaining estimates of distance between the mobile device and the vehicle, thereby acquiring a time series of estimates of distance, the time series of estimates of distance comprising a previous estimate and a current estimate, the current estimate being later in the time series than the previous estimate, the step of obtaining the previous estimate and the current estimate being performed by the processor;
selecting by the processor a selected distance estimate from the current estimate and the previous estimate based on the one or more movement-related indications; and
notifying automatically the asset-installed system of a predetermined distance condition being met by the selected distance estimate in response to the predetermined distance condition being met by the selected distance estimate.
2 . The method of claim 1 , wherein:
the predetermined distance condition is an arrival distance condition that is met by the selected distance estimate when the mobile device moves to within a predetermined arrival distance of the vehicle;
the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle; and
the step of notifying comprises sending an arrival notification from the mobile device to the VCS;
the method further comprising the VCS unlocking the vehicle in response to receiving the arrival notification.
3 . The method of claim 1 , wherein:
the predetermined distance condition is an arrival distance condition that is met by the selected distance estimate when the mobile device moves to within a predetermined arrival distance of the vehicle;
the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle; and
the step of notifying comprises sending an arrival notification from the mobile device to the VCS;
the method further comprising the VCS disarming one or more security features of the vehicle or of the VCS in response to receiving the arrival notification.
4 . The method of claim 1 , wherein:
the predetermined distance condition is a departure distance condition that is met by the selected distance estimate when the mobile device moves to beyond a predetermined departure distance from the vehicle;
the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle; and
the step of notifying comprises sending a departure notification from the mobile device to the VCS;
the method further comprising the VCS locking the vehicle in response to receiving the departure notification.
5 . The method of claim 1 , wherein:
the predetermined distance condition is a departure distance condition that is met by the selected distance estimate when the mobile device moves to beyond a predetermined departure distance from the vehicle;
the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle; and
the step of notifying comprises sending a departure notification from the mobile device to the VCS;
the method further comprising the VCS arming one or more security features of the vehicle or of the VCS in response to receiving the departure notification.
6 . The method of claim 1 , wherein a rate of the transmissions by the processor of the mobile device varies based on the previous estimate and the current estimate.
7 . The method of claim 1 , wherein the mobile device is selected from the group consisting of a smartphone, a smartwatch, and a biometric implant.
8 . The method of claim 1 , wherein the step of obtaining the previous estimate and the current estimate comprises assigning the RSSIs into a plurality of time slots, trimming lower and upper RSSIs in each time slot, averaging remaining RSSIs of said each time slot to obtain RSSI average for said each time slot, interpolating RSSI averages for the time slots with missing RSSI averages if time slots with missing RSSI averages are present, filtering the RSSI averages with a Kalman filter to derive a plurality of RSSI-derived values, and computing the previous estimate and the current estimate from the RSSI-derived values.
9 . The method of claim 1 , wherein the step of obtaining the previous estimate and the current estimate comprises:
determining speed of the mobile device based on the movement-related indications; and
discarding a current RSSI of the RSSIs in response to the step of determining the speed resulting in a speed determination in excess of a predetermined speed threshold.
10 . The method of claim 1 , wherein the one or more movement sensors includes at least one of an accelerometer, a gyrometer, an inertial sensors, or a magnetometer.
11 . The method of claim 1 , wherein the step of obtaining the previous estimate and the current estimate comprises a step for processing the RSSIs to obtain the previous estimate and the current estimate.
12 . The method of claim 1 , further comprising a step for varying the predetermined distance condition based on output of a light sensor of the mobile device.
13 . The method of claim 1 , wherein the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle and the transmissions are sent by a transceiver of the VCS.
14 . The method of claim 1 , wherein the asset-installed system comprises a vehicle control system (VCS) installed in the vehicle and a beacon installed in the vehicle, and the beacon transmissions are sent by a transceiver of the beacon.
15 . A method of automatic passive action operation, the method comprising:
obtaining received signal strength indications (RSSIs) of radio frequency (RF) transmissions of a vehicle control system (VCS) through a transceiver of a mobile device, by a processor of the mobile device, wherein the VCS is installed in a vehicle;
obtaining movement-related indications of the mobile device by the processor;
step for estimating distance between the mobile device and the vehicle based on the RSSIs and the movement-related indications, resulting in a time series of estimates of distance, the time series of estimates of distance comprising a previous estimate and a current estimate, the current estimate being later in the time series than the previous estimate;
modifying a rate of the transmissions based on the previous estimate and the current estimate;
selecting a selected distance estimate from the current estimate and the previous estimate based on the one or more movement-related indications;
sending from the mobile device to the VCS a notification in response to a predetermined distance condition being met by the selected distance estimate; and
performing one or more automatic actions by the VCS in response to the notification.
16 . The method of claim 15 , wherein the predetermined distance condition is an arrival distance condition that is met by the selected distance estimate when the mobile device moves to within a predetermined arrival distance of the vehicle.
17 . The method of claim 16 , further comprising the VCS unlocking one or more access points of the vehicle and disarming one or more security features of the vehicle or of the VCS in response to receiving the notification.
18 . The method of claim 15 , wherein the predetermined distance condition is a departure distance condition that is met by the selected distance estimate when the mobile device moves to beyond a predetermined departure distance from the vehicle.
19 . The method of claim 18 , further comprising the VCS locking one or more access points of the vehicle and arming one or more security features of the vehicle or of the VCS in response to receiving the notification.
20 . The method of claim 15 , wherein the step of obtaining the previous estimate and the current estimate comprises assigning the RSSIs into a plurality of time slots, trimming lower and upper RSSIs in each time slot, and averaging remaining RSSIs of said each time slot to obtain RSSI average for said each time slot.