Robot localization system

• US 7,970,491 B2
• Filed: 12/30/2003
• Issued: 06/28/2011
• Est. Priority Date: 12/30/2002
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Jay-woo, Lee, Hyoung-ki, Bang, Seok-won
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): JEN, MINGJEN
• Application Number:
  US10/747,228
• Publication Number:
  US 20040158354A1
• Time in Patent Office: 2,737 Days
• Field of Search: 701/300, 701/301, 701/218, 342/46, 342/47, 342/146, 342/147, 342/450, 342/453, 342/463, 342/457, 342/125, 700/50, 700/30, 700/33, 700/55
• US Class Current: 700/245
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/028 using a RF signal

Abstract

A robot localization system is provided. The robot localization includes a robot, which moves within a predetermined space and performs predetermined tasks, and a docking station corresponding to a home position of the robot. The docking station includes a first transmitting unit, which transmits a sound wave to detect a position of the robot; and a second transmitting unit, which transmits a synchronizing signal right when the sound wave is transmitted. The robot includes a first receiving unit, which comprises at least two sound sensors receiving the sound wave incident onto the robot; a second receiving unit, which receives the synchronizing signal incident onto the robot; a distance calculation unit, which calculates a distance between the first transmitting unit and the first receiving unit using a difference between an instant of time when the synchronizing signal is received and an instant of time when the sound wave is received; and an incident angle calculation unit, which calculates an incident angle of the sound wave onto the robot using a difference between receiving times of the sound wave in the at least two sound sensors comprised in the first receiving unit.

Claims

1. A robot localization system comprising:

a first transmitter which transmits a first radio wave;

a second receiver having at least two sensors which receives a second radio wave;

a distance calculator which calculates a distance between the robot and a docking station based on the first transmitted radio wave and the received second radio wave;

an incident angle calculator which calculates an incident angle of the second radio wave onto the robot using a difference between receiving times of the second radio wave in the at least two sensors of the second receiver;

an encoder to measure movements of the robot, with the encoder measuring a positional change between a previous position of the robot and a current position of the robot and a directional change of the robot between a previous direction the robot was orientated toward and a current direction the robot is orientated toward, based on the measured movements of the robot between the previous position and the current position; and

a state observer, which estimates respective unique values, within a space, of an estimated current position and an estimated current orientation of the robot with respect to the docking station, distinct from a current position and orientation measured by the encoder, by collectively using the distance between the robot and the docking station, the incident angle of the second radio wave, the positional change from the encoder, and the directional change from the encoder,

wherein the docking station comprising;

a first receiver which receives the first radio wave; and

a second transmitter which transmits the second radio wave a predetermined period of time after the first radio wave is received.

2. The robot localization system of claim 1, wherein the state observer comprises a Kalman filter which estimates the orientation of the robot using the positional and directional changes measured by the encoder.

3. The robot localization system of claim 1, wherein the distance calculator calculates the distance between the robot and the docketing station using a difference between an instant of time when the first radio wave is transmitted and an instant of time when the second radio wave is received and a predetermined period of time from the reception of the first radio wave to the transmission of the second radio wave.

4. A localization method of a robot having a first transmitter which transmits a first radio wave and a second receiver having at least two sensors which receives a second radio wave, the method comprising:

calculating a distance between the robot and a docking station, with the docking station having a first receiver which receives the first radio wave and a second transmitter which transmits the second radio wave a predetermined period of time after the first radio wave is received, based on the first transmitted radio wave and the received second radio wave;

calculating an incident angle of the second radio wave onto the robot using a difference between receiving times of the second radio wave in the at least two sensors comprised in the second receiver;

measuring movements of the robot, including measuring a positional change between a previous position of the robot and a current position of the robot and a directional change of the robot between a previous direction the robot was orientated toward and a current direction the robot is orientated toward, based on the measured movements of the robot between the previous position and the current position; and

estimating respective unique values, within a space, of an estimated current position and an estimated current orientation of the robot with respect to the docking station, distinct from a current position and orientation of the robot measured by the measuring of the movements of the robot, by collectively using the distance between the robot and the docking station, the incident angle of the second radio wave, the positional change, and the directional change.

5. The localization method of claim 4, wherein the calculating of the distance between the robot an the docking station uses a difference between an instant of time when the first radio wave is transmitted and an instant of time when the second radio wave is received and a predetermined period of time from the reception of the first radio wave to the transmission of the second radio wave.