Shopping cart self-tracking in an indoor environment

Patent metadata

Field	Value
Publication number	US-2025058814-A1
Application number	US-202418937402-A
Country	US
Kind code	A1
Filing date	Nov 5, 2024
Priority date	Jun 30, 2022
Publication date	Feb 20, 2025
Grant date	—

Abstract

A shopping cart's tracking system determines a baseline location of the shopping cart at a first timestamp with a wireless device located on the shopping cart detecting one or more external wireless devices (e.g., RFID tags). The shopping cart's tracking system receives wheel motion data from one or more wheel sensors coupled to one or more wheels of the shopping cart, wherein the wheel motion data describes rotation and orientation of the one or more wheels. The shopping cart's tracking system calculates a translation traveled by the shopping cart from the baseline location based on the wheel motion data. The shopping cart's tracking system determines an estimated location of the shopping cart at a second timestamp based on the baseline location and the translation. The shopping cart provides functionality with the estimated location.

First claim

What is claimed is:

1 . A method, performed by a computer system comprising a processor and a non-transitory computer-readable storage medium, comprising:
receiving a baseline location of a shopping cart at a first timestamp and wheel motion data from one or more wheel sensors coupled to one or more wheels of the shopping cart, the wheel motion data describing a rotation of each of the one or more wheels and an orientation of each of the one or more wheels measured as an angle along an axis orthogonal to a ground plane; calculating a translation traveled by the shopping cart from the baseline location, the translation indicating a direction and a distance traveled by the shopping cart, wherein calculating the translation comprises:
calculating the direction traveled by aggregating the orientations of the one or more wheels, and
calculating the distance traveled by integrating the rotations of the one or more wheels over time;
determining an estimated location of the shopping cart at a second timestamp based on the baseline location and the translation including the direction and the distance traveled; and providing functionality associated with the estimated location of the shopping cart.

2 . The method of claim 1 , wherein receiving the baseline location of the shopping cart at the first timestamp comprises:
receiving proximity data from one or more external wireless devices; and determining the baseline location of the shopping cart based on the proximity data and known locations of the one or more external wireless devices.

3 . The method of claim 2 ,
wherein receiving the proximity data comprises:
sending an interrogation pulse using a wireless device located on the shopping cart, and
receiving a response signal from at least one external wireless device; and
wherein determining the baseline location of the shopping cart based on the proximity data comprises:
calculating, by the computer processor, a distance between the shopping cart and the one external wireless device based on time of flight between the interrogation pulse and the response signal, wherein the baseline location is based on the distance.

4 . The method of claim 1 , wherein rotation of a wheel is about an axis that is parallel to a ground plane.

5 . The method of claim 1 , wherein the wheel sensor is a rotary encoder.

6 . The method of claim 1 , wherein the wheel motion data describes rotation and orientation of two of the wheels on the shopping cart.

7 . The method of claim 1 , wherein providing functionality associated with the estimated location of the shopping cart comprises:
displaying, on a display on the shopping cart, the estimated location of the shopping cart.

8 . The method of claim 1 , wherein providing functionality associated with the estimated location of the shopping cart comprises:
displaying, on a display on the shopping cart, content based on the estimated location of the shopping cart.

9 . The method of claim 8 , wherein displaying the content based on the estimated location of the shopping cart comprises:
generating navigational instructions to navigate to an item based on a known location of the item and the estimated location of the shopping cart; and displaying the navigational instructions on the display of the shopping cart.

10 . The method of claim 1 , further comprising:
receiving inertial measurement unit (IMU) data from an IMU sensor describing movement of the shopping cart, wherein determining the estimated location of the shopping cart comprises determining the estimated location of the shopping cart further based on the IMU data.

11 . A non-transitory computer-readable storage medium storing instructions that, when executed by a computer processor, cause the computer processor to perform operations comprising:
receiving a baseline location of a shopping cart at a first timestamp and wheel motion data from one or more wheel sensors coupled to one or more wheels of the shopping cart, the wheel motion data describing a rotation of each of the one or more wheels and an orientation of each of the one or more wheels measured as an angle along an axis orthogonal to a ground plane; calculating a translation traveled by the shopping cart from the baseline location, the translation indicating a direction and a distance traveled by the shopping cart, wherein calculating the translation comprises:
calculating the direction traveled by aggregating the orientations of the one or more wheels, and
calculating the distance traveled by integrating the rotations of the one or more wheels over time;
determining an estimated location of the shopping cart at a second timestamp based on the baseline location and the translation including the direction and the distance traveled; and providing functionality associated with the estimated location of the shopping cart.

12 . The non-transitory computer-readable storage medium of claim 11 , wherein receiving the baseline location of the shopping cart at the first timestamp comprises:
receiving proximity data from one or more external wireless devices; and determining the baseline location of the shopping cart based on the proximity data and known locations of the one or more external wireless devices.

13 . The non-transitory computer-readable storage medium of claim 12 ,
wherein receiving the proximity data comprises:
sending an interrogation pulse using a wireless device located on the shopping cart, and
receiving a response signal from at least one external wireless device; and
wherein determining the baseline location of the shopping cart based on the proximity data comprises:
calculating, by the computer processor, a distance between the shopping cart and the one external wireless device based on time of flight between the interrogation pulse and the response signal, wherein the baseline location is based on the distance.

14 . The non-transitory computer-readable storage medium of claim 11 , wherein rotation of a wheel is about an axis that is parallel to a ground plane.

15 . The non-transitory computer-readable storage medium of claim 11 , wherein the wheel sensor is a rotary encoder.

16 . The non-transitory computer-readable storage medium of claim 11 , wherein the wheel motion data describes rotation and orientation of two of the wheels on the shopping cart.

17 . The non-transitory computer-readable storage medium of claim 11 , wherein providing functionality associated with the estimated location of the shopping cart comprises:
displaying, on a display on the shopping cart, the estimated location of the shopping cart.

18 . The non-transitory computer-readable storage medium of claim 11 , wherein providing functionality associated with the estimated location of the shopping cart comprises:
displaying, on a display on the shopping cart, content based on the estimated location of the shopping cart.

19 . The non-transitory computer-readable storage medium of claim 18 , wherein displaying the content based on the estimated location of the shopping cart comprises:
generating navigational instructions to navigate to an item based on a known location of the item and the estimated location of the shopping cart; and displaying the navigational instructions on the display of the shopping cart.

20 . A computer system comprising:
a computer processor; and a non-transitory computer-readable storage medium storing instructions that, when executed by the computer processor, cause the computer proces

Assignees

• Maplebear Inc

Inventors

• Gao Lin
• Huang Yilin
• Yang Shiyuan
• Zhou Xiaofei
• Chu Kaiyang
• Zhu Sikun

Classifications

• G07C5/04

  using counting means or digital clocks · CPC title

• G01S5/0036

  of measured values, i.e. measurement on mobile and position calculation on base station · CPC title

• G01C21/16

  by integrating acceleration or speed, i.e. inertial navigation · CPC title

• G01C21/383

  Indoor data · CPC title

• B62B3/1424

  Electronic display devices · CPC title