Vehicle control by pitch modulation
First Claim
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 each aft wheel;
a controller governs the at least one motor actuator in such a manner as to dynamically stabilize the vehicle when the forward wheel is not in contact with an underlying surface, the controller governing the at least one motor actuator according to a control law independent of whether the forward wheel is in contact with the underlying surface.
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0 Petitions
Accused Products
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.
119 Citations
10 Claims
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1. A vehicle comprising:
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a plurality of wheels, including at least one forward wheel and at least one aft wheel;
at least one motor actuator that drives each aft wheel;
a controller governs the at least one motor actuator in such a manner as to dynamically stabilize the vehicle when the forward wheel is not in contact with an underlying surface, the controller governing the at least one motor actuator according to a control law independent of whether the forward wheel is in contact with the underlying surface. - View Dependent Claims (2, 3, 4, 5)
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6. A vehicle comprising:
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a first fore-wheel coupled to a first pivot point by a first strut;
a second fore-wheel coupled to the first pivot point by a second strut; and
at least one aft-wheel coupled to the first pivot point;
wherein the first and second struts are spaced apart from one another and are arranged an configured to cause the vehicle to vary its direction of motion by causing the first fore-wheel and the second fore-wheel to both pivot at least about their respective vertical axis or inclined axis.
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7. A vehicle comprising:
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a central pivot point;
a first fore-wheel coupled to the central pivot point by a first strut, the first strut being arranged and configured to rotate about the central pivot during operation;
a second fore-wheel coupled to the central pivot by a second strut, the second strut being arranged and configured to rotate about the central pivot during operation; and
at least one aft-wheel coupled to the central pivot by a connecting member arranged configured to retain a fixed orientation with respect to the central pivot.
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8. A vehicle comprising:
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a plurality of wheels, including at least one forward wheel and at least two aft wheels;
at least one motor actuator that drives each aft wheel;
at least one yaw controller; and
a controller that controls the at least one motor actuator such that a direction imparted on the at least one forward wheel by the yaw controller is replicated by differential rotation of the at least two aft wheels. - View Dependent Claims (9)
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10. A vehicle comprising:
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a plurality of wheels, including at least one forward wheel and at least two aft wheels;
at least one motor actuator that drives each aft wheel;
at least one yaw controller;
a throttle;
a controller that, when all of the plurality of wheels is in contact with a surface being traversed, causes the vehicle to accelerate when the throttle is rotated and that, when the at least one forward wheel is not in contact with a surface being traversed, causes an offset from a pitch limit to be adjusted when the throttle is rotated.
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Specification