Coaxial two-wheeled vehicle and its control method

• US 8,543,294 B2
• Filed: 05/25/2012
• Issued: 09/24/2013
• Est. Priority Date: 07/29/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Oikawa, Susumu
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): PATEL, SHARDUL D
• Application Number:
  US13/481,136
• Publication Number:
  US 20120232757A1
• Time in Patent Office: 487 Days
• Field of Search: 701/41, 180/218, 180/6.5, 700/279
• US Class Current: 701/41
• CPC Class Codes: A63C 17/01 Skateboards A63C17/02 - A63C17/28 take precedence; rolling devices on skis A63C5/035
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B62K 11/007 Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider
• CPC Class Codes: G05D 1/0891 specially adapted for land vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

To provide a coaxial two-wheeled vehicle capable of performing a turning movement with stability and its control method. A coaxial two-wheeled vehicle in accordance with the present invention includes drive means to drive two coaxially-arranged wheels, turning reference-input input means to input a turning reference input, and control means to control the drive means according to a turning gain based on a turning reference-input input by the turning reference-input input means to thereby perform a turning movement. The control means preferably brings the turning gain to substantially zero when the coaxial two-wheeled vehicle is in a backward traveling state with a backward speed greater than or equal to a first speed, and sets the turning gain to a value greater than zero when a vehicle speed is substantially zero.

Claims

1. A control method for a coaxial two-wheeled vehicle, comprising:

detecting a vehicle velocity; and

performing turning control so as to decrease a turning radius as the detected vehicle velocity decreases, wherein

the coaxial two-wheeled vehicle moves with a rider riding thereon, and

if it is determined that a brake control action is initiated during a turning movement and the vehicle velocity is thereby decreased, a decrease of a turning radius is suppressed so that a spiraling-in movement is suppressed.

2. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement, a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as time elapses.

3. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the turning velocity command value is decreased by decreasing a gain value, and setting is performed such that the gain value becomes zero when the vehicle velocity becomes zero.

4. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement, a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as the detected vehicle velocity lowers.

5. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein if it is determined that a brake control action is initiated during a turning movement,

(a) a turning velocity command value used to determine a wheel velocity difference between two wheels is decreased as time elapses when the vehicle velocity is less than a predetermined value, and

(b) the turning velocity command value is decreased as the vehicle velocity decreases when the vehicle velocity is greater than or equal to the predetermined value.

6. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the coaxial two-wheeled vehicle comprises:

a step portion on which a rider rides;

an operation lever portion that is connected to the step portion and used to operate the coaxial two-wheeled vehicle; and

a turning operation unit that is provided in the operation lever portion and used to operate a turning movement of the coaxial two-wheeled vehicle.

7. The control method for a coaxial two-wheeled vehicle according to claim 6, wherein if it is determined that a brake control action is initiated during a turning movement, a decrease of a turning radius is suppressed by lowering an operation sensitivity to an operation signal from the operation lever portion or the turning operation unit.

8. The control method for a coaxial two-wheeled vehicle according to claim 1, wherein the coaxial two-wheeled vehicle comprises:

a posture sensor that detects a posture value of the coaxial two-wheeled vehicle;

a control unit that calculates a posture velocity command value based on the posture value detected by the posture sensor; and

a wheel drive unit that rotationally drives a wheel based on a wheel velocity command value calculated from the posture velocity command value from the control unit and the turning velocity command value from a turning control unit that performs turning control.