# US 2021/0333354 A1 · Positioning device, positioning system, mobile terminal, and positioning method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333354 A1 - Document ID: US20210333354A1 - Status: Published application - Kind: A1 - Application number: 17/368,320 - Filed: 2021-07-06 - Published: 2021-10-28 - Earliest claimed: 2019-02-15 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Masanari NAKAMURA; Tetsutaro YAMADA; Hiroshi KAMEDA - Web page: https://patentgrep.com/patent/US20210333354A1 ## CPC - G01S 5/02216: {Timing or synchronisation of the receivers} - G01S 5/0294: {Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering} - G01S 5/0226: {Transmitters} - G01S 5/10: Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements {, e.g. omega or decca systems}(G01S5/12 takes precedence {; beacons and receivers cooperating therewith G01S1/306, G01S1/308}) - G01S 5/14: Determining absolute distances from a plurality of spaced points of known location - G01S 5/18: using ultrasonic, sonic or infrasonic waves - G01S 5/26: Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/28 takes precedence) - G01S 2205/02: Indoor - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A positioning device operates in cooperation with a signal receiver for receiving a plurality of signal waves arriving from at least one synchronous transmission unit including a plurality of signal transmitters that operates in synchronization with each other. The positioning device includes: a time-of-arrival detecting unit for detecting time of arrival of each of the plurality of signal waves on the basis of a reception signal output from the signal receiver and a distance difference calculating unit for calculating a difference in distance from the plurality of signal transmitters to the signal receiver as a set of observation values on the basis of a difference in the time of arrival that has been detected; and a positioning arithmetic unit. The positioning arithmetic unit calculates a time series of an estimation state vector indicating position information of the signal receiver by executing a positioning arithmetic operation based on a nonlinear Kalman filter using a time series of an observation vector indicating the set of the observation values and known position information of the plurality of signal transmitters. ## Claims ### Claim 1 A positioning device for operating in cooperation with a signal receiver for receiving a plurality of signal waves arriving from at least one synchronous transmitter comprising a plurality of signal transmitters that operates in synchronization with each other, the positioning device comprising: processing circuitry configured to detect time of arrival of each of the plurality of signal waves on a basis of a reception signal output from the signal receiver; calculate a difference in distance from the plurality of signal transmitters to the signal receiver as a set of observation values on a basis of a difference in the time of arrival that has been detected; and calculate an estimation state vector indicating position information of the signal receiver by executing a positioning arithmetic operation based on a nonlinear Kalman filter using an observation vector indicating the set of the observation values and known position information of the plurality of signal transmitters. ### Claim 2 (depends on 1) The positioning device according to claim 1, wherein the at least one synchronous transmitter includes a plurality of synchronous transmitters, each of the plurality of synchronous transmitters includes M signal transmitters (M is an integer greater than or equal to 2), and the processing circuitry calculates the set of the observation values for each of the synchronous transmitters. ### Claim 3 (depends on 1) The positioning device according to claim 1, wherein the processing circuitry is further configured to execute a correlation process between the reception signal and a reference signal; and calculate, as the time of arrival, time that corresponds to a peak having an amplitude or power greater than or equal to a threshold value among a plurality of peaks appearing in an output signal to which the correlation processing is executed. ### Claim 4 (depends on 3) The positioning device according to claim 3, wherein the processing circuitry sets the threshold value on a basis of a peak other than the peak having a maximum amplitude among the plurality of peaks. ### Claim 5 (depends on 1) The positioning device according to claim 1, wherein the processing circuitry estimates time of arrival of each of the plurality of signal waves by executing a maximum likelihood estimating process. ### Claim 6 (depends on 1) The positioning device according to claim 1, wherein the processing circuitry estimates time of arrival of each of the plurality of signal waves by executing a maximum likelihood estimating process using predicted time of arrival of each of the plurality of signal waves. ### Claim 7 (depends on 1) The positioning device according to claim 1, wherein the processing circuitry calculates a plurality of candidates for the estimation state vector by executing a positioning arithmetic operation based on the nonlinear Kalman filter, calculates a plurality of evaluation values each indicating a likelihood of the plurality of candidates, and selects at least one candidate from among the plurality of candidates on a basis of the plurality of evaluation values. ### Claim 8 (depends on 1) The positioning device according to claim 1, wherein the plurality of signal waves is sound waves in a non-audible range. ### Claim 9 (depends on 1) A mobile terminal comprising the positioning device according to claim 1 and the signal receiver. ### Claim 10 (depends on 1) A positioning system comprising the at least one synchronous transmitter and a mobile terminal including the positioning device according to claim 1 and the signal receiver. ### Claim 11 A positioning method executed in a positioning device for operating in cooperation with a signal receiver for receiving a plurality of signal waves arriving from at least one synchronous transmitter comprising a plurality of signal transmitters that operates in synchronization with each other, the positioning method comprising: detecting time of arrival of each of the plurality of signal waves on a basis of a reception signal output from the signal receiver; calculating a difference in distance from the plurality of signal transmitters to the signal receiver as a set of observation values on a basis of a difference in the time of arrival that has been detected; and calculating an estimation state vector indicating position information of the signal receiver by executing a positioning arithmetic operation based on a nonlinear Kalman filter using an observation vector indicating the set of the observation values and known position information of the plurality of signal transmitters.