A communication device including a clock, a memory, and at least one processor is disclosed. The at least one processor is configured to execute instructions stored in the memory that cause the at least one processor to perform operations including receiving at least one message from a second communication device of a plurality of communication devices over a preconfigured time duration, determining a first local time of the clock of the communication device at which the at least one message from the second communication device is received, and determining a sync-time of the second communication device based on the at least one message from the second communication device. The operations include mapping the sync-time of the second communication device based on the first local time and the determined sync-time of the second communication device and adjusting a sync-time of the communication device based on the second local time.

A communication device including a clock, a memory, and at least one processor is disclosed. The at least one processor is configured to execute instructions stored in the memory that cause the at least one processor to perform operations including receiving at least one message from a second communication device of a plurality of communication devices over a preconfigured time duration, determining a first local time of the clock of the communication device at which the at least one message from the second communication device is received, and determining a sync-time of the second communication device based on the at least one message from the second communication device. The operations include mapping the sync-time of the second communication device based on the first local time and the determined sync-time of the second communication device and adjusting a sync-time of the communication device based on the second local time.

A system and methods for estimating the location of a mobile device are disclosed. In accordance with one embodiment, a mobile device receives a wireless electromagnetic signal and an ultrasound signal from a first beacon during a first occurrence of a time slot. The mobile device further receives a wireless electromagnetic signal and an ultrasound signal from a second beacon during a second occurrence of the time slot, where the ultrasound signals from the first and second beacons have non-overlapping areas of coverage. The electromagnetic and ultrasound signals from the first beacon are used to estimate a first location of the mobile device, and the electromagnetic and ultrasound signals from the second beacon are used to estimate a second location of the mobile device.

A sensor may be automatically calibrated during manufacture by providing a sensor processing unit having an integrated sensor, performing a check to determine if the integrated sensor has been previously calibrated upon a reset. When it has been determined the integrated sensor has not been previously calibrated, an automated calibration pattern may be imparted to the sensor so that a calibration parameter is determined.

A sensor may be automatically calibrated during manufacture by providing a sensor processing unit having an integrated sensor, performing a check to determine if the integrated sensor has been previously calibrated upon a reset. When it has been determined the integrated sensor has not been previously calibrated, an automated calibration pattern may be imparted to the sensor so that a calibration parameter is determined.

Systems, methods, and apparatus are provided in a vehicle having a Hitch Articulation Angle (HAA) calculation system for estimating an HAA between the vehicle and a towed trailer. The method includes: receiving a plurality of ultrasonic sensor (USS) range measurements for a first USS on the vehicle while the vehicle is towing the trailer in a forward direction; receiving a plurality of HAA values calculated using geometric equations or a kinematic model that correspond to the plurality of USS range measurements; receiving a USS range measurement for the first USS while the vehicle is operating in a reverse direction or experiencing a high HAA but not from a second USS; estimating an HAA value from the USS range measurement by applying the USS curve characteristics for the first USS; and providing the estimated HAA value to a vehicle motion control system for use in controlling vehicle and trailer motion.

Systems, methods, and apparatus are provided in a vehicle having a Hitch Articulation Angle (HAA) calculation system for estimating an HAA between the vehicle and a towed trailer. The method includes: receiving a plurality of ultrasonic sensor (USS) range measurements for a first USS on the vehicle while the vehicle is towing the trailer in a forward direction; receiving a plurality of HAA values calculated using geometric equations or a kinematic model that correspond to the plurality of USS range measurements; receiving a USS range measurement for the first USS while the vehicle is operating in a reverse direction or experiencing a high HAA but not from a second USS; estimating an HAA value from the USS range measurement by applying the USS curve characteristics for the first USS; and providing the estimated HAA value to a vehicle motion control system for use in controlling vehicle and trailer motion.

A method includes transmitting a first electromagnetic signal from a first node to a second node and receiving a second electromagnetic signal from the second node at the first node. The method also includes repeating the transmission of the first electromagnetic signal and the reception of the second electromagnetic signal multiple times. The method further includes identifying, based on the repeated transmissions and receptions, a time-of-flight associated with a travel time for one of the electromagnetic signals to travel between the first and second nodes. The time-of-flight is indicative of a distance between the nodes.

The present invention provides a method of position sensing between a wireless mobile component carrying a mobile ultrasonic transducer and a fixed component carrying a plurality of fixed ultrasonic transducers in a predetermined spaced-apart relationship, the method comprising turning off all the transducers to establish a period of silence, activating one or more of the fixed transducers to transmit an ultrasonic signal, starting a plurality of timers corresponding to the respective plurality of fixed transducers generally simultaneously with transmitting the signal, receiving the signal at the mobile transducer, transmitting a signal from the mobile transducer responsive to the received signal, receiving the signal transmitted by the mobile transducer at each fixed transducer and stopping the respective timer generally at the time of reception of an edge of the received signal found within the first twenty received edges and preferably within the first ten received edges and more preferably at the first received rising edge, calculating the distance between the mobile transducer and each fixed transducer based on a predetermined constant representative of the speed of sound and the time taken for transit of the signal to each fixed transducer as measured by the respective timers, and performing trigonometric calculations using the calculated distances in order to determine the 3-dimensional position of the mobile component relative to the fixed component.

The present invention provides a method of position sensing between a wireless mobile component carrying a mobile ultrasonic transducer and a fixed component carrying a plurality of fixed ultrasonic transducers in a predetermined spaced-apart relationship, the method comprising turning off all the transducers to establish a period of silence, activating one or more of the fixed transducers to transmit an ultrasonic signal, starting a plurality of timers corresponding to the respective plurality of fixed transducers generally simultaneously with transmitting the signal, receiving the signal at the mobile transducer, transmitting a signal from the mobile transducer responsive to the received signal, receiving the signal transmitted by the mobile transducer at each fixed transducer and stopping the respective timer generally at the time of reception of an edge of the received signal found within the first twenty received edges and preferably within the first ten received edges and more preferably at the first received rising edge, calculating the distance between the mobile transducer and each fixed transducer based on a predetermined constant representative of the speed of sound and the time taken for transit of the signal to each fixed transducer as measured by the respective timers, and performing trigonometric calculations using the calculated distances in order to determine the 3-dimensional position of the mobile component relative to the fixed component.