Front wheel drive engagement control system for agricultural vehicles
First Claim
1. In an agricultural vehicle having an engine, a first pair of wheels driven by the engine, a second pair of wheels and an engagement circuit for selectively engaging and disengaging the second pair of wheels to the engine in response to control signals for driving the second pair of wheels, a control system comprising:
- a vehicle velocity sensor including a radar emitter and a radar receiver configured to detect a parameter indicative of the ground velocity of the vehicle independent of the velocity of the second pair of wheels and to generate a vehicle velocity signal representative thereof;
a wheel velocity sensor configured to detect the velocity of at least one of the first pair of wheels and to generate a wheel velocity signal representative thereof;
a comparator circuit coupled to the vehicle velocity sensor and to the wheel velocity sensor and configured to compare the vehicle velocity signal and the wheel velocity signal and to generate a slip signal representative of the degree of slip of at least one of the first pair of wheels; and
a control circuit coupled to the comparator circuit and to the engagement circuit and configured to generate control signals and to apply the control signals to the engagement circuit, wherein the control signals cause the engagement circuit to engage the engine and thereby drive the second pair of wheels when the degree of slip is above a predetermined value and to disengage the engine and thereby not drive the second pair of wheels when the degree of slip is below the predetermined value.
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0 Petitions
Accused Products
Abstract
A control system for engaging, disengaging and re-engaging a front wheel drive in an agricultural vehicle includes a control circuit configured to receive signals representative of vehicle operating parameters and to generate control signals corresponding to the desired state (i.e. engaged or disengaged) of a front wheel drive engagement circuit. Sensors are associated with the rear wheels, rear service brakes, implement positioning circuit, the vehicle body and the front axle to provide parameter signals related to wheel speed, braking, implement position and vehicle speed. Control logic executed by the control circuit in a continuously cycled routine determines the desired state of the engagement circuit based upon all operating parameters. The control circuit applies an appropriate control signal to the engagement circuit causing engagement or disengagement in accordance with the desired state.
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Citations
22 Claims
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1. In an agricultural vehicle having an engine, a first pair of wheels driven by the engine, a second pair of wheels and an engagement circuit for selectively engaging and disengaging the second pair of wheels to the engine in response to control signals for driving the second pair of wheels, a control system comprising:
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a vehicle velocity sensor including a radar emitter and a radar receiver configured to detect a parameter indicative of the ground velocity of the vehicle independent of the velocity of the second pair of wheels and to generate a vehicle velocity signal representative thereof; a wheel velocity sensor configured to detect the velocity of at least one of the first pair of wheels and to generate a wheel velocity signal representative thereof; a comparator circuit coupled to the vehicle velocity sensor and to the wheel velocity sensor and configured to compare the vehicle velocity signal and the wheel velocity signal and to generate a slip signal representative of the degree of slip of at least one of the first pair of wheels; and a control circuit coupled to the comparator circuit and to the engagement circuit and configured to generate control signals and to apply the control signals to the engagement circuit, wherein the control signals cause the engagement circuit to engage the engine and thereby drive the second pair of wheels when the degree of slip is above a predetermined value and to disengage the engine and thereby not drive the second pair of wheels when the degree of slip is below the predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. In an agricultural vehicle having an engine, a first pair of wheels driven by the engine, a pair of brakes each associated with one of the driven wheels, a second pair of wheels, an engagement circuit for selectively engaging and disengaging the second pair of wheels to the engine in response to control signals for driving the second pair of wheels, and an implement positioning system for raising and lowering an implement coupled to the vehicle, a control system comprising.
a vehicle velocity sensor configured to detect a parameter indicative of the ground velocity of the vehicle and to generate a vehicle velocity signal representative thereof; -
a pair of brake detecting circuits each coupled to one of the brakes and configured to generate a brake signal representative of the state of the one brake; an implement position detecting circuit coupled to the implement positioning system and configured to generate an implement position signal representative of the implement position; and a control circuit coupled to the vehicle velocity sensor, the brake detecting circuits, the implement position detecting circuit and to the engagement circuit and configured to generate control signals and to apply the control signals to the engagement circuit to engage the engine and thereby drive the second pair of wheels when the implement is in a working position, the ground velocity of the vehicle is below a predetermined speed threshold, and neither or a single brake is applied. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. In an agricultural vehicle having an engine, a first pair of wheels driven by the engine, a brake associated with each of the driven wheels, a second pair of wheels, an engagement circuit for selectively engaging and disengaging the second pair of wheels to the engine in response to control signals and means for positioning an implement, a control system comprising:
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first sensing means for sensing a first operating parameter of the vehicle and for producing a first parameter signal representative thereof, the first operating parameter being the position of the implement; second sensing means for sensing a second operating parameter of the vehicle and for producing a second parameter signal representative thereof; third sensing means for sensing a third operating parameter of the vehicle and for producing a third parameter signal representative thereof; and a control circuit coupled to the first sensing means, the second sensing means, the third sensing means and the engagement circuit and configured to generate control signals for selectively engaging and disengaging the engine to the second pair of wheels in response to the first parameter signal, the second parameter signal and the third parameter signal, whereby the second pair of wheels is driven or not driven, respectively. - View Dependent Claims (19, 20)
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21. In an agricultural vehicle having an engine, a first pair of wheels driven by the engine, a pair of brakes each associated with one of the driven wheels, a second pair of wheels, an engagement circuit for selectively engaging and disengaging the second pair of wheels to the engine in response to control signals for driving the second pair of wheels, and an implement positioning system for raising and lowering an implement coupled to the vehicle, a control system comprising:
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a vehicle velocity sensor configured to detect a parameter indicative of the ground velocity of the vehicle and to generate a vehicle velocity signal representative thereof; a pair of brake detecting circuits each coupled to one of the brakes and configured to generate a brake signal representative of the state of the one brake; an implement position detecting circuit coupled to the implement positioning system and configured to generate an implement position signal representative of the implement position; and a control circuit coupled to the vehicle velocity sensor, the brake detecting circuits, the implement position detecting circuit and the engagement circuit and configured to generate control signals and to apply the control signals to the engagement circuit to engage the engine and thereby drive the second pair of wheels when the implement is in a working position and the vehicle velocity signal is below a predetermined speed threshold, regardless of the state of the brakes. - View Dependent Claims (22)
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Specification