Estimating motion of wheeled carts
First Claim
1. A navigation method for a human-propelled wheeled cart, the method comprising:
- determining a position of the human-propelled cart with a dead reckoning navigation system that is in an active navigation mode;
measuring, with a vibration sensor disposed on the human-propelled cart, vibration data representative of vibrations experienced by the human-propelled cart as the human-propelled cart travels over a surface;
analyzing the vibration data to detect an entrance event associated with the human-propelled cart crossing through an entrance to a building;
analyzing the vibration data to detect a vibration signature associated with the surface; and
updating a navigation parameter of the dead reckoning navigation system based at least partly on the detected vibration signature, wherein the navigation parameter comprises one or more of;
a surface roughness, a coordinate of a boundary associated with the surface, or a spacing or a width associated with expansion joints or tile joints; and
in response to the detection of the entrance event, transitioning the dead reckoning navigation system to an inactive navigation mode in which position of the human-propelled cart is not determined by the dead reckoning navigation system.
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Accused Products
Abstract
Examples of systems and methods for locating movable objects such as carts (e.g., shopping carts) are disclosed. Such systems and methods can use dead reckoning techniques to estimate the current position of the movable object. Various techniques for improving accuracy of position estimates are disclosed, including compensation for various error sources involving the use of magnetometer and accelerometer, and using vibration analysis to derive wheel rotation rates. Also disclosed are various techniques to utilize characteristics of the operating environment in conjunction with or in lieu of dead reckoning techniques, including characteristic of environment such as ground texture, availability of signals from radio frequency (RF) transmitters including precision fix sources. Such systems and methods can be applied in both indoor and outdoor settings and in retail or warehouse settings.
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Citations
17 Claims
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1. A navigation method for a human-propelled wheeled cart, the method comprising:
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determining a position of the human-propelled cart with a dead reckoning navigation system that is in an active navigation mode; measuring, with a vibration sensor disposed on the human-propelled cart, vibration data representative of vibrations experienced by the human-propelled cart as the human-propelled cart travels over a surface; analyzing the vibration data to detect an entrance event associated with the human-propelled cart crossing through an entrance to a building; analyzing the vibration data to detect a vibration signature associated with the surface; and updating a navigation parameter of the dead reckoning navigation system based at least partly on the detected vibration signature, wherein the navigation parameter comprises one or more of;
a surface roughness, a coordinate of a boundary associated with the surface, or a spacing or a width associated with expansion joints or tile joints; andin response to the detection of the entrance event, transitioning the dead reckoning navigation system to an inactive navigation mode in which position of the human-propelled cart is not determined by the dead reckoning navigation system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification