Patent ID: 11859980
Assignee: URSROBOT INC.
Field: Measurement (Instruments)
Classification: CPC G  A  H | IPC G  H

Claim 0:
1. A method of movement tracking, the method to be implemented by a processing module included in a lawn mower, the lawn mower further including a control module, said method comprising, before a working area is defined:
A) periodically performing, when it is determined by the processing module that signal strength of an external positioning signal is greater than a predefined strength threshold, positioning based on the external positioning signal so as to locate the processing module, and generating a first path record based on a result of the positioning;
B) periodically performing, when it is determined by the processing module that the signal strength of the external positioning signal is not greater than the predefined strength threshold, measurement of a variation in movement of the processing module, and generating a second path record based on a result of the measurement of the variation in movement;
C) performing, when it is determined by the processing module that the signal strength of the external positioning signal increases from being not greater than the predefined strength threshold to being greater than the predefined strength threshold, positioning based on the external positioning signal so as to obtain a coordinate set of an exact position (PN′) of the processing module; and
D) computing, based on the second path record and the coordinate set of the exact position of the processing module, corrected path data related to the second path record, and generating a movement path record based on the first path record and the corrected path data,
wherein the movement path record indicates a surrounding boundary which defines and surrounds the working area,
said method further comprising, after the working area is defined:
E) generating first navigation data and second navigation data based on the movement path record, the first navigation data containing plural entries of first working path data that respectively indicate a plurality of first working paths which are arranged in sequence in the working area and which are parallel to and spaced apart from each other, the second navigation data containing plural entries of second working path data that respectively indicate a plurality of second working paths which are arranged in sequence in the working area and which are parallel to and spaced apart from each other, any adjacent two of the second working paths arranged in the working area are closer to each other than any adjacent two of the first working paths arranged in the working area are to each other;
F) when it is determined by the processing module that the signal strength of the external positioning signal is greater than a predefined power threshold, operating in a first navigation mode where the processing module performs positioning based on the external positioning signal so as to locate the processing module, and outputs to the control module, based on the result of the positioning and the first navigation data, a first navigation signal that is related to the first working paths; and
G) when it is determined by the processing module that the signal strength of the external positioning signal is not greater than the predefined power threshold, operating in a second navigation mode where the processing module performs positioning by means of inertial measurement so as to locate the processing module, and outputs to the control module, based on the result of the positioning and the second navigation data, a second navigation signal that is related to the second working paths,
wherein after receiving the first navigation signal, the control module controls, based on the first navigation signal, the lawn mower to move along the first working paths to cut grass, and
wherein after receiving the second navigation signal, the control module controls, based on the second navigation signal, the lawn mower to move along the second working paths to cut grass.