PUSHCART

• US 20150183463A1
• Filed: 03/16/2015
• Published: 07/02/2015
• Est. Priority Date: 09/18/2012
• Status: Abandoned Application

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Shirato, Kenichi, Tsuji, Shigeru
• Application Number:
  US14/658,566
• Publication Number:
  US 20150183463A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61H 2003/043 with a drive mechanism
• CPC Class Codes: A61H 2003/046 with braking means
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5028 Contact activation, i.e. activated at contact with a surface of the user to be treated
• CPC Class Codes: A61H 2201/5069 Angle sensors
• CPC Class Codes: A61H 2201/5084 Acceleration sensors
• CPC Class Codes: A61H 2201/5092 Optical sensor
• CPC Class Codes: A61H 3/04 Wheeled walking aids for disabled persons A61H3/06 takes precedence
• CPC Class Codes: B62D 11/003 Electric or electronic control systems
• CPC Class Codes: B62D 11/02 by differentially driving ground-engaging elements on opposite vehicle sides
• CPC Class Codes: B62K 11/007 Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider

Abstract

Provided is a pushcart that can automatically change a yaw rotation range. A first main wheel (11A) and a second main wheel (11B) are respectively driven and controlled so that a change of angle in a yaw direction falls within a range of given target values (a first target value and a second target value). In the case where a yaw angular velocity ω is determined to be in a range from −α to α, a control unit (21) controls the first main wheel (11A) and the second main wheel (11B) so that the yaw angular velocity ω becomes 0, and corrects the yaw angular velocity to 0 (or a value near 0). Accordingly, the yaw angular velocity ω falls within the range from the first target value to the second target value (−α to α).

Claims

1. A pushcart comprising:

a pair of wheels;

a main body portion that supports the pair of wheels so as to be rotatable in a pitch direction;

a driving control unit that drives and controls each wheel in the pair of wheels individually; and

a yaw detection means that detects a change of angle of the main body portion in a yaw direction,

wherein the driving control unit drives and controls each wheel in the pair of wheels individually so that the change of angle in the yaw direction falls within a range from a first target value to a second target value.

2. The pushcart according to claim 1,

wherein in the case where the change of angle in the yaw direction is within a first predetermined value range for a predetermined amount of time, the driving control unit sets the first target value and the second target value to fall within the first predetermined value range.

3. The pushcart according to claim 2, further comprising:

a first input means that accepts an input of the first predetermined value range.

4. The pushcart according to claim 1,

wherein in the case where the change of angle in the yaw direction is outside a second predetermined value range for a predetermined amount of time, the driving control unit sets the first target value and the second target value to fall within the second predetermined value range.

5. The pushcart according to claim 4, further comprising:

a second input means that accepts an input of the second predetermined value range.

6. The pushcart according to claim 1, further comprising:

a roll detection means that detects a change of angle of the main body portion in a roll direction,

wherein in the case where the change of angle in the roll direction is outside a third predetermined value range for a predetermined amount of time, the driving control unit changes the first target value and/or the second target value.

7. The pushcart according to claim 6, further comprising:

a third input means that accepts an input of the third predetermined value range.

8. The pushcart according to claim 1, further comprising:

a target value input means that accepts an input of the first target value or the second target value.

9. The pushcart according to claim 1,

wherein the yaw detection means detects the change of angle in the yaw direction by detecting a rotation angle or an angular velocity of each wheel in the pair of wheels.

10. The pushcart according to claim 9,

wherein the yaw detection means includes a yaw angular velocity sensor or a magnetic sensor.

11. The pushcart according to claim 1, wherein the yaw detection means comprises a magnetic sensor that detects an angle of a current front direction of the pushcart relative to a front direction of the pushcart when the pushcart is stopped.

12. The pushcart according to claim 1, wherein the yaw detection means comprises a rotary encoder that detects rotation angles of each of the wheels in the pair of wheels.

13. The pushcart according to claim 1, wherein the yaw detection means comprises a rotary encoder, a magnetic sensor, a yaw angular velocity sensor, a slope angle sensor, an accelerometer, or combinations thereof.

14. The pushcart according to claim 2,

wherein in the case where the change of angle in the yaw direction is outside a second predetermined value range for a predetermined amount of time, the driving control unit sets the first target value and the second target value to fall within the second predetermined value range.

15. The pushcart according to claim 3,

wherein in the case where the change of angle in the yaw direction is outside a second predetermined value range for a predetermined amount of time, the driving control unit sets the first target value and the second target value to fall within the second predetermined value range.

16. The pushcart according to claim 2, further comprising:

a roll detection means that detects a change of angle of the main body portion in a roll direction,

wherein in the case where the change of angle in the roll direction is outside a third predetermined value range for a predetermined amount of time, the driving control unit changes the first target value and/or the second target value.

17. The pushcart according to claim 3, further comprising:

a roll detection means that detects a change of angle of the main body portion in a roll direction,

wherein in the case where the change of angle in the roll direction is outside a third predetermined value range for a predetermined amount of time, the driving control unit changes the first target value and/or the second target value.

18. The pushcart according to claim 4, further comprising:

a roll detection means that detects a change of angle of the main body portion in a roll direction,

wherein in the case where the change of angle in the roll direction is outside a third predetermined value range for a predetermined amount of time, the driving control unit changes the first target value and/or the second target value.

19. The pushcart according to claim 5, further comprising:

a roll detection means that detects a change of angle of the main body portion in a roll direction,

wherein in the case where the change of angle in the roll direction is outside a third predetermined value range for a predetermined amount of time, the driving control unit changes the first target value and/or the second target value.

20. The pushcart according to claim 2, further comprising:

a target value input means that accepts an input of the first target value or the second target value.