# US 12,120,579 B2 · Methods and systems for orienting a mobile device to a vehicle's reference frame > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,120,579 B2 - Document ID: US12120579B2 - Status: Granted - Kind: B2 - Application number: 17/406,373 - Filed: 2021-08-19 - Published: 2022-02-10 - Granted: 2024-10-15 - Earliest claimed: 2016-04-18 - Assignees: Cambridge Mobile Telematics Inc. - Applicants: Cambridge Mobile Telematics Inc. - Inventors: Brad Cordova; Sanujit Sahoo; Sushrut Karnik - Web page: https://patentgrep.com/patent/US12120579B2 ## CPC - H04W 4/029: Location-based management or tracking services - G01C 21/20: Instruments for performing navigational calculations (G01C21/24, G01C21/26 take precedence) - H04M 1/725: Cordless telephones (user interfaces specially adapted therefor H04M1/724) - H04W 4/026: {using orientation information, e.g. compass} - H04M 2250/10: including a GPS signal receiver - H04M 2250/12: including a sensor for measuring a physical value, e.g. temperature or motion - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) ## Abstract A method of providing a quaternion for reference frame transformation includes (a) initiating a driving event in a vehicle having a vehicle reference frame and (b) receiving, from a mobile device, mobile device data associated with a time stamp. The method also includes (c) computing a quaternion operable to transform the mobile device data to the vehicle reference frame and (d) determining if the driving event is complete. The method further includes incrementing the time stamp and iterating steps (a), (b), (c), and (d) if the driving event is not complete and providing the quaternion for reference frame transformation if the driving event is complete. ## Claims ### Claim 1 A method of providing a quaternion for reference frame transformation, the method comprising: (a) initiating a driving event in a vehicle having a vehicle reference frame; (b) receiving, from a mobile device having a mobile device reference frame, mobile device data associated with a time stamp; (c) determining, from the mobile device data, a first orientation of a gravity vector with respect to a first axis of the mobile device reference frame; (d) determining, from the mobile device data, a second orientation of a magnetic direction with respect to a second axis of the mobile device reference frame; (e) determining, using Global Positioning System (GPS) data provided by a GPS unit, a direction of travel for the vehicle with respect to the magnetic direction; (f) determining a vertical inclination angle for the vehicle, wherein determining the vertical inclination angle for the vehicle comprises determining an altitude change and a distance change using the GPS data provided by the GPS unit; (g) computing a quaternion that represents a rotation between the mobile device reference frame and the vehicle reference frame using the first orientation, the second orientation, the direction of travel and the vertical inclination angle for the vehicle; (h) determining if the driving event is complete; incrementing the time stamp and iterating steps (b), (c), (d), (e), (f), (g), and (h) if the driving event is not complete; and providing the quaternion for reference frame transformation if the driving event is complete. ### Claim 2 (depends on 1) The method of claim 1 wherein the mobile device data is received in the mobile device reference frame. ### Claim 3 (depends on 2) The method of claim 2 wherein iterating steps (b), (c), (d), (e), (f), (g), and (h) produces a vector including a plurality of quaternions as a function of time. ### Claim 4 (depends on 3) The method of claim 3 further comprising using the vector to convert a string of the mobile device data in the mobile device reference frame into a string of data referenced to the vehicle reference frame. ### Claim 5 (depends on 2) The method of claim 2 further comprising utilizing the quaternion to transform the mobile device data in the mobile device reference frame into the vehicle reference frame. ### Claim 6 (depends on 1) The method of claim 1 further comprising: obtaining motion data from the mobile device during the driving event; orienting the obtained motion data to the vehicle reference frame using the quaternion; and identifying a use of the mobile device by a driver during the driving event in response to: determining that the mobile device has moved to the left with respect to the vehicle; and determining that a front screen of the mobile device faces to the left with respect to the vehicle. ### Claim 7 (depends on 6) The method of claim 6 wherein determining that the front screen of the mobile device faces to the left with respect to the vehicle is performed after determining that the mobile device has moved to the left with respect to the vehicle. ### Claim 8 (depends on 6) The method of claim 6 wherein the motion data from the mobile device is obtained in the mobile device reference frame. ### Claim 9 (depends on 6) The method of claim 6 wherein the motion data includes accelerometer data. ### Claim 10 (depends on 6) The method of claim 6 wherein the motion data includes magnetometer data. ### Claim 11 (depends on 6) The method of claim 6 wherein the motion data is oriented to the vehicle reference frame by aligning a first axis of the mobile device with a gravity vector, aligning a second axis of the mobile device with a magnetic vector, and aligning the second axis to the direction of travel. ### Claim 12 (depends on 1) The method of claim 1, wherein computing the quaternion comprises: generating, from the first orientation of the gravity vector with respect to the first axis of the mobile device reference frame, a first quaternion that rotates the mobile device reference frame to align the first axis with the gravity vector; generating, from the second orientation of the magnetic direction with respect to the second axis of the mobile device reference frame, a second quaternion that rotates the mobile device reference frame to align the second axis with the magnetic direction; generating, from the direction of travel for the vehicle, a third quaternion that represents a rotation from the magnetic direction to the direction of travel for the vehicle; and combining the first quaternion, the second quaternion, and the third quaternion into the quaternion.