Mobile Robot Docking Pose Estimation via Signal Reflection Filtering

Solution Overview

Problem

Mobile robots face challenges in accurately returning to a charging station due to changes in the station's position and incorrect signal detection, leading to random wandering or wall-following motions.

Innovation Solution

A method and apparatus that update or add candidate estimated poses of a signal transmitting unit based on detected docking signals, using a pose estimation algorithm like the Kalman filter, to improve the accuracy of the mobile robot's return to the charging station by prioritizing poses in order of accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the mobile robot uses a single estimated pose of the charging station, then the system complexity is low, but the docking accuracy deteriorates when the charging station position changes or signals are reflected

Engineering Contradiction:

Improvedocking accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the charging station position estimation into multiple candidate poses instead of using a single estimate. The pose estimation unit generates multiple possible positions, and the mobile robot attempts docking in order of accuracy. This segmentation allows the system to maintain low complexity while improving accuracy by trying multiple hypotheses sequentially.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by pre-calculating and storing multiple candidate poses of the charging station before the actual docking attempt. The mobile robot prepares a list of possible positions in advance, ordered by accuracy, so that when docking is needed, it can immediately try the most accurate pose without real-time computation delays.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the mobile robot wanders randomly or makes wall-following motion to detect the docking signal, then the robot can eventually find the charging station, but the time required increases significantly

Engineering Contradiction:

Improvedocking reliabilityVSAvoiddocking time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by pre-calculating and storing multiple candidate poses of the charging station before the actual docking attempt. The mobile robot prepares a list of possible positions in advance, ordered by accuracy, so that when docking is needed, it can immediately try the most accurate pose without real-time computation delays.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously monitoring whether the docking signal is detected during the return process. If the signal is not detected at the current pose, the system feedbacks to the control unit to try the next candidate pose in the list. This feedback mechanism allows the robot to efficiently navigate to the correct position without random wandering.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If the mobile robot detects a docking signal reflected by the wall or floor, then the robot can detect the signal, but it wrongly recognizes the position of the charging station

Engineering Contradiction:

Improveposition recognition accuracyVSAvoidsignal reflection interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the charging station position estimation into multiple candidate poses instead of using a single estimate. The pose estimation unit generates multiple possible positions, and the mobile robot attempts docking in order of accuracy. This segmentation allows the system to maintain low complexity while improving accuracy by trying multiple hypotheses sequentially.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent converts the harmful effect of signal reflection into a benefit by using multiple candidate poses. Instead of being misled by reflected signals, the system generates multiple possible positions including those that account for reflection paths. The mobile robot tries these poses in order of accuracy, and the correct position will eventually be found even if some candidates are based on reflected signals.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS8255084B2Method, medium, and apparatus for docking mobile robot

Publication Date: 2012.08.28 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided are a method, medium, and apparatus for docking a mobile robot. The method includes: (a) receiving a docking signal, which is transmitted from a signal transmitting unit, by using a signal receiving unit loaded in the mobile robot while the mobile robot is moving; (b) estimating a range of poses of the signal transmitting unit based on the received docking signal; (c) updating estimated poses of the signal transmitting unit by reflecting the estimated range of poses in a pose estimation algorithm when the pose of the signal transmitting unit, which was estimated using the pose estimation algorithm, exists within the estimated range of poses and adding a new pose of the signal transmitting unit, which is to be estimated using the pose estimation algorithm by reflecting the estimated range of poses, when the pose of the signal transmitting unit, which was estimated using the pose estimation algorithm, does not exist within the estimated range of poses; and (d) attempting to return the mobile robot to a charging station by using a plurality of poses of the signal transmitting unit, which were estimated by repeating operations (a) through (c) and using the pose estimation algorithm, in order of accuracy, until the mobile robot is docked in the charging station.