# US 12,601,598 B2 · Trajectory prediction with data normalization

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,601,598 B2
- Document ID: US12601598B2
- Status: Granted
- Kind: B2
- Application number: 18/257,172
- Filed: 2021-12-07
- Published: 2024-03-21
- Granted: 2026-04-14
- Earliest claimed: 2020-12-14
- Assignees: Assa Abloy AB
- Applicants: Assa Abloy AB
- Inventors: Jianbo Chen; Kapil Sachdeva; Sylvain Jacques Prevost
- Web page: https://patentgrep.com/patent/US12601598B2

## CPC

- G01C 21/206: {specially adapted for indoor navigation}
- G01C 21/12: executed aboard the object being navigated; Dead reckoning
- G07C 9/00571: {operated by interacting with a central unit}
- G07C 9/28: the pass enabling tracking or indicating presence
- H04W 4/33: for indoor environments, e.g. buildings
- H04W 12/63: Location-dependent; Proximity-dependent
- H04W 12/71: Hardware identity
- 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)
- G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

Methods and systems (100) for trajectory prediction are provided. The methods and systems (100) include operations comprising: receiving (501) a plurality of observed speed points; processing (502) the plurality of observed speed points corresponding to the observed trajectory by a machine learning technique to generate a plurality of predicted speed points, the machine learning technique being trained to establish a relationship between a plurality of training observed speed points and training predicted speed points; determining (503) a future trajectory based on the plurality of predicted speed points, each of the plurality of predicted speed points corresponding to a different slice of a plurality of slices of the future trajectory; determining (504) that a target access control device is within a threshold range of the future trajectory; and performing (505) an operation associated with the target access control device (110).

## Claims

### Claim 1

A method comprising:
receiving, from a client device, by one or more processors, a plurality of observed speed points, each of the plurality of observed speed points corresponding to a different slice of a plurality of slices of an observed trajectory;
retrieving a first timestamp of a first of the plurality of observed speed points representing when the first of the plurality of speed points was received from the client device and a second timestamp of a second of the plurality of observed speed points representing when the second of the plurality of speed points was received from the client device, the first and second speed points being determined by the client device using a wireless communication antenna;
determining a sampling rate of the client device based on a difference between the first timestamp and the second timestamp;
processing the plurality of observed speed points corresponding to the observed trajectory by a machine learning technique to generate a plurality of predicted speed points, the machine learning technique being trained to establish a relationship between a plurality of training observed speed points and training predicted speed points;
determining a future trajectory based on the plurality of predicted speed points, each of the plurality of predicted speed points corresponding to a different slice of a plurality of slices of the future trajectory and based on the sampling rate;
determining that a target access control device is within a threshold range of the future trajectory; and
in response to determining that the target access control device is within the threshold range of the future trajectory, performing an operation associated with the target access control device.

### Claim 2 (depends on 1)

The method of claim 1, wherein the plurality of observed speed points comprise acceleration measurements, wherein the plurality of predicted speed points comprise a plurality of acceleration measurements, and wherein the target access control device comprises a lock associated with a door; and
wherein the performing the operation comprises unlocking the door.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
establishing a wireless communication link between a mobile device of a user and the target access control device;
exchanging authorization information over the wireless communication link; and
performing the operation after determining that the user is authorized, based on the authorization information, to access the target access control device.

### Claim 4 (depends on 3)

The method of claim 3, further comprising:
determining that the user is authorized, based on the authorization information, to access the target access control device prior to performing the operation; and
delaying performing the operation after determining that the user is authorized until the target access control device is determined to be within the threshold range of the future trajectory.

### Claim 5 (depends on 3)

The method of claim 3, wherein the wireless communication link comprises a first communication protocol; and
wherein the plurality of observed speed points are received over a second communication protocol.

### Claim 6 (depends on 5)

The method of claim 5, wherein the target access control device is located indoors.

### Claim 7 (depends on 3)

The method of claim 3, further comprising:
determining that the user is authorized, based on the authorization information, to access the target access control device prior to performing the operation; and
preventing performing the operation after determining that the user is authorized in response to determining that the target access control device is outside of the threshold range of the future trajectory.

### Claim 8 (depends on 1)

The method of claim 1, wherein the machine learning technique comprises a neural network.

### Claim 9 (depends on 1)

The method of claim 1, wherein receiving the plurality of observed speed points comprises:
receiving a first data point representing a first two-dimensional (2D) or three-dimensional (3D) Cartesian coordinate at a first time point;
receiving a second data point representing a second 2D or 3D Cartesian coordinate at a second time point, each of the first and second data points corresponding to a first slice of the plurality of slices; and
computing a first observed speed point of the plurality of observed speed points as a function of a difference between the first and second 2D or 3D Cartesian coordinates and a difference between the first and second time points.

### Claim 10 (depends on 1)

The method of claim 1, wherein the machine learning technique generates the plurality of predicted speed points independently of a sampling rate of the plurality of observed speed points.

### Claim 11 (depends on 1)

The method of claim 1, wherein determining the future trajectory based on the plurality of predicted speed points comprises:
computing three-dimensional Cartesian coordinates of the future trajectory based on the plurality of predicted speed points, a current location of a user, and the sampling rate at which the plurality of observed speed points is received.

### Claim 12 (depends on 1)

The method of claim 1, further comprising training the machine learning technique by:
obtaining a first batch of training data comprising a first set of the plurality of training observed speed points and a corresponding first set of the training predicted speed points;
processing the first set of the training observed speed points with the machine learning technique to generate a plurality of estimated speed points;
computing, based on a loss function, a loss based on a deviation between the plurality of estimated speed points and the corresponding first set of the training predicted speed points; and
updating parameters of the machine learning technique based on the computed loss function.

### Claim 13 (depends on 12)

The method of claim 12, wherein the first set of the plurality of training observed speed points correspond to a first sampling rate, further comprising:
obtaining a second batch of training data comprising a second set of the plurality of training observed speed points, wherein the second set of the plurality of training observed speed points correspond to a second sampling rate;
processing the second set of the training observed speed points with the machine learning technique to generate a second plurality of estimated speed points;
computing, based on the loss function, a second loss based on a deviation between the second plurality of estimated speed points and the corresponding first set of the training predicted speed points; and
updating parameters of the machine learning technique based on the second loss.

### Claim 14

A system comprising:
one or more processors coupled to a memory comprising non-transitory computer instructions that when executed by the one or more processors perform operations comprising:
receiving, from a client device, a plurality of observed speed points, each of the plurality of observed speed points corresponding to a different slice of a plurality of slices of an observed trajectory;
retrieving a first timestamp of a first of the plurality of observed speed points representing when the first of the plurality of speed points was received from the client device and a second timestamp of a second of the plurality of observed speed points representing when the second of the plurality of speed points was received from the client device, the first and second speed points being determined by the client device using a wireless communication antenna;
determining a sampling rate of the client device based on a difference between the first timestamp and the second timestamp;
processing the plurality of observed speed points corresponding to the observed trajectory by a machine learning technique to generate a plurality of predicted speed points, the machine learning technique being trained to establish a relationship between a plurality of training observed speed points and training predicted speed points;
determining a future trajectory based on the plurality of predicted speed points, each of the plurality of predicted speed points corresponding to a different slice of a plurality of slices of the future trajectory and based on the sampling rate;
determining that a target access control device is within a threshold range of the future trajectory; and
in response to determining that the target access control device is within the threshold range of the future trajectory, performing an operation associated with the target access control device.

### Claim 15 (depends on 14)

The system of claim 14, wherein the plurality of observed speed points comprise acceleration measurements, wherein the plurality of predicted speed points comprise a plurality of acceleration measurements, wherein the target access control device comprises a lock associated with a door; and wherein the performing the operation comprises unlocking the door.

### Claim 16 (depends on 15)

The system of claim 15, wherein the operations further comprise:
establishing a wireless communication link between a mobile device of a user and the target access control device;
exchanging authorization information over the wireless communication link; and
performing the operation after determining that the user is authorized, based on the authorization information, to access the target access control device.

### Claim 17 (depends on 16)

The system of claim 16, wherein the operations further comprise:
determining that the user is authorized, based on the authorization information, to access the target access control device prior to performing the operation; and
delaying performing the operation after determining that the user is authorized until the target access control device is determined to be within the threshold range of the future trajectory.

### Claim 18

A non-transitory computer readable medium comprising non-transitory computer-readable instructions for performing operations comprising:
receiving, from a client device, a plurality of observed speed points, each of the plurality of observed speed points corresponding to a different slice of a plurality of slices of an observed trajectory;
retrieving a first timestamp of a first of the plurality of observed speed points representing when the first of the plurality of speed points was received from the client device and a second timestamp of a second of the plurality of observed speed points representing when the second of the plurality of speed points was received from the client device, the first and second speed points being determined by the client device using a wireless communication antenna;
determining a sampling rate of the client device based on a difference between the first timestamp and the second timestamp;
processing the plurality of observed speed points corresponding to the observed trajectory by a machine learning technique to generate a plurality of predicted speed points, the machine learning technique being trained to establish a relationship between a plurality of training observed speed points and training predicted speed points;
determining a future trajectory based on the plurality of predicted speed points, each of the plurality of predicted speed points corresponding to a different slice of a plurality of slices of the future trajectory and based on the sampling rate;
determining that a target access control device is within a threshold range of the future trajectory; and
in response to determining that the target access control device is within the threshold range of the future trajectory, performing an operation associated with the target access control device.

### Claim 19 (depends on 18)

The non-transitory computer readable medium of claim 18, wherein the plurality of observed speed points comprise acceleration measurements, wherein the plurality of predicted speed points comprise a plurality of acceleration measurements, wherein the target access control device comprises a lock associated with a door; and wherein the performing the operation comprises unlocking the door.

### Claim 20 (depends on 19)

The non-transitory computer readable medium of claim 19, wherein the operations further comprise:
establishing a wireless communication link between a mobile device of a user and the target access control device;
exchanging authorization information over the wireless communication link; and
performing the operation after determining that the user is authorized, based on the authorization information, to access the target access control device.