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A mobile robot localization method to eliminate accumulated error

IP.com Disclosure Number: IPCOM000211247D
Publication Date: 2011-Sep-29
Document File: 6 page(s) / 104K

Publishing Venue

The IP.com Prior Art Database

Abstract

This article proposed a method for robust robot localization by reducing the cumulative position error in inertia based localization. Conditioned on the assumption that the robot activity yard exhibits a checkerboard pattern, a sensor arrangement as well as corresponding rule are designed to compensate the cumulative position error from inertia dead-reckon approach. Theoretically it can be verified that the error is within 3cm (depending on the line width on the ground).

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A mobile robot localization method to eliminate accumulated error

The elimination of accumulated error which is common in mobile robot localization task. Other existing solutions consists landmark based localization, inertia based localization, vision based one, and GPS based one. Inertia dead-reckon localization is more accurate than others, but it has the drawback of error accumulation. So there is an urgent need for accurate positioning which is free from error accumulation.

Correct the robot position calculated from inertia positioning, by leveraging the information from optical sensors, which is a method in terms of multi-sensor information fusion. The advantages of our invention are keeping the localization accuracy regardless of the distance robots have gone. Other localization techniques are incapable of doing this.

The system utilizes sensors including gyroscope, odometry, optical sensors. The error can be effectively reduced.

The core idea is the arrangement of three sensors under the bottom of robot. See the following figure for illustration, three red nodes indicate the sensors.

Based on the observation that one can identify the type (horizontal or vertical) of current line via leveraging the three sensor's information, the proposed method is described as follows:

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Refer to the following table, when the robot is traveling around the yard, whatever its heading angle is, there is a corresponding rule to judge whether the touching line is vertical or horizontal (if two of sensors detect a line). In doing so, the position can be modified by the updated coordinate of the line (assume the line's position is prior known).

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In order to ensure the sensor triangle can work correctly, two conditions should be considered:


(1) For a line whose width is D, there are at most two sensors on the same line.


(2) To encourage more chances for the robot to update its p...