Mobile Robot and method for controlling mobile robot

• US 20090024250A1
• Filed: 07/18/2008
• Published: 01/22/2009
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ozaki, Fumio, Oaki, Junji, Matsuhira, Nobuto
• Granted Patent: US 8,634,955 B2
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area

Abstract

A mobile robot includes: a main body; a drive unit that moves the main body; a contact force detecting unit that detects a contact force acting against an obstacle; and a controller that controls the drive unit to move the main body toward a target object under a condition that the contact force detected by the contact force detecting unit is in a predetermined range.

Claims

1. A mobile robot comprising:

a main body;

a drive unit that moves the main body;

a contact force detecting unit that detects a contact force acting against an obstacle; and

a controller that controls the drive unit to move the main body toward a target object under a condition that the contact force detected by the contact force detecting unit is in a predetermined range.

2. The mobile robot according to claim 1 further comprising an input unit that inputs information indicating characteristics of the obstacle to the controller,

wherein the controller changes the predetermined range in accordance with the information input by the input unit, and

wherein the characteristics includes a physical size of a person in a case where the obstacle is the person.

3. The mobile robot according to claim 1 further comprising a target position detecting unit that detects a target position that indicates a relative position of the target from the main body,

wherein the controller includes:

a velocity control unit that controls a velocity of movement of the main body to control a distance between the target position and a position of the main body to be in a predetermined range;

a velocity vector generating unit that generates a velocity vector based on an impedance model using the contact force as an input; and

a moving velocity composing unit that composes an output of the velocity control unit for keeping the constant distance and the velocity vector generated by the velocity vector generating unit.

4. The mobile robot according to claim 3, wherein the controller further includes a contact force attenuating unit that changes a spring constant of the impedance model to a value smaller than a current spring constant when the contact force detected by the contact force detecting unit exceeds a predetermined value.

5. The mobile robot according to claim 3, wherein the controller further includes:

a stopping unit that stops the movement of the main body when the contact force is larger than a first predetermined value; and

a avoiding unit that avoids the movement of the main body in a direction toward an external force that applies the contact force to the main body when the contact force is larger than a second predetermined value that is larger than the first predetermined value.

6. The mobile robot according to claim 3, wherein the velocity vector generating unit generates the velocity vector based on the impedance model G(s) defined by the following equation (1), wherein M is a mass, D is a damper, and K is a spring constant.

G(s)=1/(Ms²+Ds+K)  

 

(1)

7. A method for controlling a mobile robot,

wherein the mobile robot includes:

a main body;

a drive unit that moves the main body; and

a contact force detecting unit that detects a contact force acting against an obstacle, and

wherein the method comprises;

receiving the contact force from the contact force detecting unit; and

controlling the drive unit to move the main body toward a target object under a condition that the contact force is in a predetermined range.