Robotic vacuum cleaner

• US 20050235451A1
• Filed: 11/02/2004
• Published: 10/27/2005
• Est. Priority Date: 04/21/2004
• Status: Active Grant

• Current Assignee: Hunan Grand-Pro Robot Technology Co.,Ltd.
• Original Assignee: Jason Yan
• Inventors: Yan, Jason
• Granted Patent: US 7,937,800 B2
• Time in Patent Office: Days
• US Class Current: 15/319
• CPC Class Codes: A47L 2201/04 Automatic control of the travelling movement; Automatic obstacle detection
• CPC Class Codes: A47L 9/009 Carrying-vehicles; Arrangements of trollies or wheels; Means for avoiding mechanical obstacles
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area

Abstract

A robotic vacuum cleaner includes a casing with a motor-driven wheel unit mounted on a lower major wall thereof, and a tactile sensor unit yieldable radially relative to the casing. An electrical control unit is operable to control the wheel unit to operate in a starting mode in which the casing is moved along a spiral path, and, upon receipt of a switching signal generated by the sensor unit in response to a contact of the sensor unit with an obstacle, controls the wheel unit to operate in an edge-cleaning mode in which the wheel unit is initially turned to a normal angle, is then driven to move forward a predetermined distance, is subsequently turned to an activating angle, and is moved towards the obstacle to permit contact of the sensor unit with the obstacle so as to result in generation of switch signal enabling the wheel unit to continue to operate in the edge-cleaning mode.

Claims

1. A robotic vacuum cleaner comprising:

a casing having a lower major wall which is adapted to confront a floor surface to be cleaned, and which includes a central area that defines a central axis normal to said central major wall, and a surrounding peripheral area that surrounds said central area about the central axis, said surrounding peripheral area including a leading region which is positioned ahead of said central area when said casing is driven to move along the floor surface, and left and right front regions which flank said leading region;

a suction unit which is disposed in said lower major wall, and which is adapted to draw dust from the floor surface to be cleaned;

a motor-driven wheel unit which is disposed on said lower major wall and behind said leading region, and which is steerable between a normal angle, at which said leading region is movable forward straight ahead, and an activating angle at which a corresponding one of said left and right front regions is movable towards an obstacle;

a drive motor unit disposed to drive said motor-driven wheel unit to move said casing along the floor surface,

a tactile sensor unit disposed outwardly of one of said left and right front regions, and yieldable radially relative to said corresponding one of said left and right front regions so as to generate a switching signal in response to contact of said tactile sensor unit with the obstacle; and

an electrical control unit coupled to said tactile sensor unit and said drive motor unit, said electrical control unit being operable to control said motor-driven wheel unit to operate in a starting mode in which said casing is moved along a spiral path, with said leading region heading forwards, upon receipt of said switching signal from said tactile sensor unit, said electrical control unit controlling said motor-driven wheel unit to operate in an edge-cleaning mode in which said motor-driven wheel unit is initially turned to the normal angle, is then driven to move forward a predetermined distance along the floor surface, is subsequently returned to the activating angle, and is thereafter moved toward the obstacle to permit contact of said tactile sensor unit with the obstacle, thereby enabling said motor-driven wheel unit to continue to operate in the edge-cleaning mode.

2. The robotic vacuum cleaner of claim 1, wherein said surrounding peripheral area further includes left and right rear regions disposed rearwardly of said left and right front regions, respectively, said motor-driven wheel unit including left and right wheels which are mounted on said left and right rear regions, respectively, said drive motor unit including left and right drive motors which are disposed to drive said left and right wheels, respectively.

3. The robotic vacuum cleaner of claim 2, wherein said left and right wheels are disposed to be moved in opposite directions so as to steer said motor-driven wheel unit to one of the normal angle and the activating angle.

4. The robotic vacuum cleaner of claim 2, wherein said left and right wheels are disposed to be moved in the same direction and at different speeds so as to steer said motor-driven wheel unit to one of the normal angle and the activating angle.

5. The robotic vacuum cleaner of claim 2, wherein said tactile sensor unit includes a shielding plate which is mounted to said casing and which covers said leading region and said left and right front regions, and left and right sensors which are disposed between said shielding plate and said left front region, and between said shielding plate and said right front region, respectively, said shielding plate being configured to be radially movable relative to said casing such that once said shielding plate is brought to contact the obstacle, said shielding plate is moved radially toward said casing thereby to contact a corresponding one of said left and right sensors, thereby activating the corresponding one of said left and right sensors to generate the switching signal.

6. The robotic vacuum cleaner of claim 1, wherein the spiral path is constituted by a plurality of consecutive winding segments.

7. The robotic vacuum cleaner of claim 1, wherein the spiral path is constituted by a plurality of consecutive straight segments, each two adjacent ones of said consecutive straight segments being perpendicular to each other.

8. The robotic vacuum cleaner of claim 1, wherein said suction unit includes a duct which is disposed in said casing and which has a vacuum inlet extending downwardly of said lower major wall, and an impeller which is disposed in said casing and downstream of said vacuum inlet so as to draw dust from the floor surface to be cleaned.