Vehicle control by pitch modulation

• US 7,900,725 B2
• Filed: 10/11/2005
• Issued: 03/08/2011
• Est. Priority Date: 06/11/2002
• Status: Active Grant

• Current Assignee: Segway Incorporated (Ninebot Ltd.)
• Original Assignee: Segway Incorporated (Ninebot Ltd.)
• Inventors: Stevens, Jon Michael, Robinson, David W., Heinzmann, John D., Lund, Jeremy B., Field, J. Douglas
• Primary Examiner(s): Silbermann; Joanne
• Assistant Examiner(s): Scharich; Marc A
• Application Number:
  US11/249,136
• Publication Number:
  US 20060108156A1
• Time in Patent Office: 1,974 Days
• Field of Search: 180/6.2, 180/6.48, 180/6.5, 180/7.1, 180/21, 180/65.1, 180/218, 180/271, 180/282, 180/290, 280 5502- 5512, 701/124
• US Class Current: 180/65.1
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2200/24 Personal mobility vehicles
• CPC Class Codes: B60L 2200/34 Wheel chairs
• CPC Class Codes: B60L 2220/44 Wheel Hub motors, i.e. integrated in the wheel hub
• CPC Class Codes: B60L 2240/423 Torque
• 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: B60L 50/20 using propulsion power generated by humans or animals
• CPC Class Codes: B62D 37/00 Stabilising vehicle bodies without controlling suspension arrangements
• 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 17/00 Cycles not otherwise provided for
• CPC Class Codes: B62K 5/01 Motorcycles with four or more wheels specially adapted for disabled riders B62K5/003
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A method for fore-aft stabilization of a vehicle for motion in a specified direction over an underlying surface. The vehicle has at least one forward wheel and at least one aft wheel, and the forward wheel is characterized by a force normal to the instantaneous direction of motion of the vehicle. A motor actuator drives each aft wheel, and a controller governs the motor actuator or motor actuators in such a manner as to dynamically stabilize the vehicle, according to a uniform control law, when the forward wheel is in contact with the underlying surface or not. A torque is applied to the aft wheel on the basis of vehicle pitch or the force on the forward wheel normal to the direction of motion. Additionally, a periodic rotational modulation may be applied to the aft wheel, and a stabilizing torque provided based on a detected response, either of vehicle pitch or of normal force on the front wheel. Left and right motor actuators may independently control left and right aft wheels to continue turns as governed by user steering, whether or not forward wheels are in contact with the ground.

Claims

1. A vehicle comprising:

a plurality of wheels, including at least one forward wheel and at least one aft wheel;

at least one motor actuator that drives the at least one aft wheel;

a sensor that measures a vehicle pitch angle; and

a controller that continuously governs the at least one motor actuator in such a manner as to dynamically stabilize the vehicle when the at least one forward wheel is not in contact with an underlying surface, the controller continuously governing the at least one motor actuator according to a control law, wherein the control law applied to dynamically stabilize the vehicle is the same whether or not the at least one forward wheel of the vehicle is in contact with the underlying surface and wherein the control law is based on a pitch signal when the vehicle pitch angle exceeds a specified value.

2. A vehicle according to claim 1 further comprising:

a right aft actuator that drives a right aft wheel; and

a left aft actuator that drives a left aft wheel independently of the right aft wheel thus allowing the controller to govern differential rotation of the left and right aft wheels for controlling yaw of the vehicle.

3. A vehicle according to claim 1, further comprising:

a user input device for providing a throttle output signal; and

at least one pitch sensor for providing the pitch signal.

4. A vehicle according to claim 3, wherein the controller is arranged and configured to govern the at least one motor actuator according to a control law based at least upon the throttle output signal or the pitch signal or a pitch rate signal.