# US 11,112,803 B2 · Mobile robot and control method

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- Number: US 11,112,803 B2
- Document ID: US11112803B2
- Status: Granted
- Kind: B2
- Application number: 16/317,992
- Filed: 2017-07-20
- Published: 2021-03-25
- Granted: 2021-09-07
- Earliest claimed: 2016-07-21
- Assignees: Thk Co., Ltd.
- Applicants: Thk Co., Ltd.
- Inventors: Hitoshi Kitano; Takashi Naito
- Web page: https://patentgrep.com/patent/US11112803B2

## CPC

- G05D 1/0227: {using mechanical sensing means, e.g. for sensing treated area}
- G05D 1/0234: {using optical markers or beacons (optical beacons per se G01S1/70)}
- G05D 1/0088: {characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours (using knowledge based models G06N5/00)}
- G05D 1/02: Control of position or course in two dimensions
- G05D 1/0223: {involving speed control of the vehicle (vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00)}
- G05D 1/0238: {using obstacle or wall sensors (G05D1/0246 and G05D1/0289 take precedence; lidar systems designed for anti-collision purposes G01S17/93)}
- G05D 1/024: {in combination with a laser (lasers per se H01S)}
- A47L 2201/04: Automatic control of the travelling movement; Automatic obstacle detection
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08)

## Abstract

A mobile robot includes a driving unit which changes a moving velocity and a traveling direction, a detection unit which detects a plurality of detection objects disposed along a traveling path to a target point, and a control unit which acquires a distance and a direction to the detection object detected by the detection unit, calculates a traveling direction in which the distance to the detection object and the direction of the detection object satisfy a predetermined relationship, and controls the driving unit based on the calculated traveling direction.

## Claims

### Claim 1

A mobile robot, comprising:
a driving unit which changes a moving velocity and a traveling direction;
a detection sensor which detects a distance to an object existing sideward when a traveling direction is defined as forward at a predetermined cycle;
a detection unit which detects a plurality of detection objects disposed along a traveling path to a target point; and
a processor connected to the driving unit, the detection sensor, and the detection unit, the processor executing instructions to
acquire a distance and a direction to a detection object detected by the detection unit,
calculate an angle indicating an inclination of a first travel direction with respect to the traveling path from a variation amount of the distance detected by the detection sensor in the predetermined cycle and a traveled distance in the predetermined cycle, wherein the first travel direction is a current travel direction of the mobile robot,
calculate a second traveling direction from which the first travel direction is changed to keep the mobile robot at a constant distance with respect to a boundary of the traveling path based on the distance to the detection object and the direction of the detection object corrected by the angle, and
control the driving unit to turn the mobile robot to the second direction.

### Claim 2 (depends on 1)

The mobile robot according to claim 1,
wherein the processor calculates the traveling direction such that the distance to the object detected by the detection sensor is constant.

### Claim 3 (depends on 1)

The mobile robot according to claim 1, wherein the processor accesses a table which preliminarily stores a distance to the traveling path of each of the detection objects,
wherein the processor acquires a distance between a detection object detected by the detection unit and the traveling path, and calculates the traveling direction based on an angle obtained from arcsin(X/Z) when the acquired distance is set to X and the distance to the detected detection object is set to Z.

### Claim 4 (depends on 3)

The mobile robot according to claim 3, wherein
the table stores information on which of a right side and a left side of each of the detection objects is disposed with respect to the traveling path to the target point, and
the processor calculates the traveling direction based on a position of the detected detection object with respect to the traveling path.

### Claim 5 (depends on 3)

The mobile robot according to claim 3, wherein
the table stores a rotation information indicating presence or absence of a change of the traveling direction at each of the detection objects, and
with the change of the traveling direction with respect to the detected detection object being present in the table, the processor changes the traveling direction when the distance to the detected detection object reaches a predetermined distance.

### Claim 6 (depends on 3)

The mobile robot according to claim 3, wherein
the table stores information indicating a detection object closest to the target point, and
with the detected detection object being the detection object closest to the target point, the processor controls the driving unit such that the driving unit stops when the distance to the detected detection object reaches a predetermined distance.

### Claim 7

A control method of a mobile robot including a driving unit which changes a moving velocity and a traveling direction, a detection unit which detects a plurality of detection objects disposed along a traveling path to a target point, and a detection sensor which detects a distance to an object existing sideward when a traveling direction is defined as forward, the method comprising the steps of:
detecting a distance to the object existing sideward at a predetermined cycle by the detection sensor;
acquiring a distance and a direction to a detection object detected by the detecting unit;
calculating an angle indicating an inclination of a first travel direction with respect to the traveling path from a variation amount of the distance detected by the detection sensor in the predetermined cycle and a traveled distance in the predetermined cycle, wherein the first travel direction is a current travel direction of the mobile robot;
calculating a second traveling direction from which the first travel direction is changed to keep the mobile robot at a constant distance with respect to a boundary of the traveling path based on the distance to the detection object and the direction of the detection object corrected by the angle; and
controlling the driving unit to turn the mobile robot to the second direction.

### Claim 8 (depends on 2)

The mobile robot according to claim 2,
wherein the processor accesses a table which preliminarily stores a distance to the traveling path of each of the detection objects,
wherein the processor acquires a distance between a detection object detected by the detection unit and the traveling path, and calculates the traveling direction based on an angle obtained from arcsin(X/Z) when the acquired distance is set to X and the distance to the detected detection object is set to Z.

### Claim 9 (depends on 4)

The mobile robot according to claim 4, wherein
the table stores a rotation information indicating presence or absence of a change of the traveling direction at each of the detection objects, and
with the change of the traveling direction with respect to the detected detection object being present in the table, the processor changes the traveling direction when the distance to the detected detection object reaches a predetermined distance.

### Claim 10 (depends on 4)

The mobile robot according to claim 4, wherein
the table stores information indicating a detection object closest to the target point, and
with the detected detection object being the detection object closest to the target point, the processor controls the driving unit such that the driving unit stops when the distance to the detected detection object reaches a predetermined distance.

### Claim 11 (depends on 5)

The mobile robot according to claim 5, wherein
the table stores information indicating a detection object closest to the target point, and
with the detected detection object being the detection object closest to the target point, the processor controls the driving unit such that the driving unit stops when the distance to the detected detection object reaches a predetermined distance.