Non-linear control of a balancing vehicle

• US 20040007398A1
• Filed: 06/12/2003
• Published: 01/15/2004
• Est. Priority Date: 05/27/1994
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Field, J. Douglas, Morrell, John B., Kerwin, John M., Amsbury, Burl, Pompa, Jonathan B.
• Granted Patent: US 6,827,163 B2
• Time in Patent Office: Days
• US Class Current: 180/7.1
• CPC Class Codes: A61G 5/065 with three or more wheels mounted on a rotary cross member, e.g. spiders or spoked wheels with small wheels at the end of the spokes
• CPC Class Codes: B60K 7/00 Disposition of motor in, or adjacent to, traction wheel roller-skate driving mechanisms A63C17/12
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/16 Single-axle vehicles
• CPC Class Codes: B60L 2200/24 Personal mobility vehicles
• CPC Class Codes: B60L 2220/46 Wheel motors, i.e. motor connected to only one wheel
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/18 lateral
• CPC Class Codes: B60L 2240/20 angular
• CPC Class Codes: B60L 2240/22 Yaw angle
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/461 Speed
• CPC Class Codes: B60L 2240/463 Torque
• CPC Class Codes: B60L 2260/34 Stabilising upright position of vehicles, e.g. of single axle vehicles
• CPC Class Codes: B62D 57/00 Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track sledges B62B; motor sledges B62M
• CPC Class Codes: B62K 11/007 Automatic balancing machines with single main ground engaging wheel or coaxial wheels supporting a rider
• CPC Class Codes: B62K 2204/00 Adaptations for driving cycles by electric motor for driving electrically assisted bicycles B62M6/00
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A class of transporters for carrying an individual over ground having a surface that may be irregular. Various embodiments have a motorized drive, mounted to the ground-contacting module that causes operation of the transporter in an operating position that is unstable with respect to tipping when the motorized drive arrangement is not powered. Methods of controlling the transporter are described that allow the dynamic behavior of the transporter to more closely match preferences of a rider. These methods include providing preferential responsiveness to change in pitch angles and pitch rates.

Claims

1. A device for carrying a user, the device comprising:

a. a platform which supports a payload including the user,

b. a ground-contacting module, mounted to the platform, including at least one ground-contacting member, characterized by a ground contact region, and defining a fore-aft plane;

c. a motorized drive arrangement, coupled to the ground-contacting module;

the drive arrangement, ground-contacting module and payload constituting a system being unstable with respect to tipping in at least the fore-aft plane when the motorized drive is not powered, the system characterized by a pitch angle offset from a specified pitch angle and a pitch rate offset from a specified pitch rate; and

d. a control loop in which the motorized drive arrangement is included, for dynamically maintaining stability of the system in the fore-aft plane by operation of the motorized drive arrangement so that the net torque experienced by the system about the region of contact with the surface causes a specified acceleration of the system, the net torque including a contribution related to the pitch angle offset multiplied by a first gain wherein the first gain is a function of at least one of an orientation and a displacement of the device.

2. A balancing transporter characterized by an instantaneous displacement and orientation, the transporter comprising:

a. a motorized drive for propelling the transporter;

b. a control loop in which the motorized drive arrangement is included, for dynamically maintaining stability of the system in the fore-aft plane by operation of the motorized drive arrangement so that the net torque experienced by the system about the region of contact with the surface causes a specified acceleration of the system, the net torque including a contribution functionally related to at least one of the pitch angle, pitch rate, wheel position and wheel velocity, wherein the functional relation varies with at least one of an orientation and a displacement of the device.

3. A method for carrying a payload including a user with a transporter, the method comprising:

a. providing a transporter including;

i. a platform which supports a payload including the user,

ii. a ground-contacting module, mounted to the platform, including at least one ground-contacting member, characterized by a ground contact region and a fore-aft plane;

iii. a motorized drive arrangement, coupled to the ground-contacting module;

the drive arrangement, ground-contacting module and payload constituting a system being unstable with respect to tipping in at least the fore-aft plane when the motorized drive is not powered, the system characterized by a pitch angle offset from a specified pitch angle and a pitch rate offset from a specified pitch rate; and

b. causing the motorized drive to operate the ground-contacting module using a control loop in which the motorized drive arrangement is included, for dynamically maintaining stability of the system in the fore-aft plane by operation of the motorized drive arrangement so that the net torque experienced by the system about the region of contact with the surface causes a specified acceleration of the system, the net torque including;

i. a contribution related to the pitch angle offset multiplied by a first gain K₁′

when the pitch angle offset is greater than or equal to zero and to the pitch angle offset multiplied by a second gain K₁″

when the pitch angle offset is less than zero; and

ii. a contribution related to the pitch rate offset multiplied by a third gain K₂′

;

when the pitch rate offset is greater than or equal to zero and to the pitch rate offset multiplied by a fourth gain K₂″

when the pitch rate offset is less than zero, wherein at least one of a first gain pair consisting of K₁′ and

K₁″ and

a second gain pair consisting of K₂′ and

K₂″

are unequal.

4. A method according to claim 3 wherein the magnitude of K₁′

is less than the magnitude of K₁″

5. A method according to claim 3 wherein K₂′

equals K₂″

.