Using a can bus engine torque/speed message as load feedback for implement draft control

• US 7,954,556 B2
• Filed: 08/17/2006
• Issued: 06/07/2011
• Est. Priority Date: 08/17/2006
• Status: Active Grant

• Current Assignee: Blue Leaf IP Incorporated (CNH Industrial N.V.)
• Original Assignee: CNH Industrial America LLC (CNH Industrial N.V.)
• Inventors: Hou, Yanming, Guo, Haibo
• Primary Examiner(s): Will; Thomas B
• Assistant Examiner(s): MITCHELL, JOEL F
• Application Number:
  US11/465,325
• Publication Number:
  US 20080053669A1
• Time in Patent Office: 1,755 Days
• Field of Search: 172/3, 172/7, 172/12
• US Class Current: 172/7
• CPC Class Codes: A01B 63/112 to control draught load, i.e. tractive force

Abstract

A draft load control system for an agricultural tractor having electronic engine and draft load controllers interconnected by a digital communications bus over which parameters for engine load are made readily available to the draft load controller. The draft load control system is suitable for front-mounted, rear-mounted, or towed implements without requiring additional sensing equipment.

Claims

1. A draft load control system for positioning a ground-engaging implement coupled to an agricultural tractor, said tractor comprising:

a ground-supported frame;

an engine supported on said frame for propelling said tractor, said coupled implement, and the operative components thereof;

a vehicle electronic communication system;

at least one auxiliary component powered by said engine and creating at least one auxiliary load;

at least one auxiliary load controller for controlling power from said engine to said at least one auxiliary load, said auxiliary load controller providing at least one output signal to said vehicle electronic communication system;

an engine control system for selectively controlling torque and speed of said engine, said engine control system providing at least one output signal to said vehicle electronic communication system;

said engine control system including at least one engine digital controller configured for directly adjusting the engine;

an operator input apparatus, said operator input apparatus accepting a desired draft load value and providing a corresponding desired draft load signal to said vehicle electronic communication system;

said ground-engaging implement having a position actuator disposed to raise and lower said implement with respect to the ground in response to an implement position control signal; and

said tractor having a draft load controller connected to said vehicle electronic communication system to receive said engine control system output signal, said at least one auxiliary load controller output signal, and said desired draft load signal, and derive, in accordance with its programming, and send an implement position control signal to said implement position actuator to manage said implement position based on said position control signal whereby a substantially constant draft load is maintained on said tractor and wherein said vehicle electronic communication system is a controller area network.

2. The draft load control system of claim 1, wherein said at least one auxiliary load controller includes at least one auxiliary load digital controller and is configured for monitoring at least one load placed on the engine other than the draft load.

3. The draft load control system of claim 2, wherein said draft load controller is a digital controller.

4. The draft load control system of claim 3, wherein said controller area network comprises a communication link connecting said at least one engine digital controller, said at least one auxiliary load digital controller, and said draft load digital controller and the draft load controller configured to calculate the draft load of the vehicle from at least one signal received from the controller area network indicating the engine torque and a detected state of a transmission of the vehicle.

5. The draft load control system of claim 1, wherein said tractor further comprises a three-point hitch movable in upward and downward directions by a hitch actuator, said implement being connected to said three-point hitch enabling said hitch to raise and lower said implement, said hitch actuator, being responsive to said implement position control signal, causes, when necessary, adjustment of said three-point hitch thereby changing implement position and actual draft load on said tractor.

6. The draft load control system of claim 5, wherein said engine control system includes at least one engine digital controller, said at least one auxiliary load controller includes at least one auxiliary load digital controller, said draft load controller is a digital controller, and said vehicle electronic communication system comprises a communication link connecting said at least one engine digital controller, said at least one auxiliary load digital controller, and said draft load digital controller.

7. The draft load control system of claim 6, wherein said draft load controller, upon receiving said engine control system output signal and said at least one auxiliary load controller output signal from said vehicle electronic communication system derives an actual draft load value, receives said desired draft load value from said vehicle electronic communication system and compares said actual draft load value to said desired draft load value, calculates an error signal based on the difference between said actual draft load value and said desired draft load value, generates an implement position control signal having a value, and sends said implement position control signal to said implement position actuator to manage said implement position based on said position control signal thereby causing said error signal to be substantially zero thereby maintaining a substantially constant draft load on said tractor.

8. A method for controlling the draft load of a ground-engaging implement coupled to an agricultural tractor, the method comprising the steps of:

providing a ground-supported agricultural tractor having an engine for motive power, an operator'"'"'s platform, and an implement position actuator movable in upward and downward directions responsive to an implement position control signal, the engine being selectively controlled by at least one engine load controller;

providing a ground-engaging implement attached to the tractor and thereby propelled by said tractor;

providing an operator input apparatus at the operator platform to establish a desired draft load value;

providing at least one auxiliary component selectively powered by the engine thereby creating at least one auxiliary load, the at least one auxiliary component being selectively controlled by at least one auxiliary load controller;

providing a vehicle electronic communication system connecting the at least one engine load controller, the at least one auxiliary load controller, and the operator input apparatus;

providing a draft load controller connected to the vehicle electronic communication system;

setting the desired draft load value using the operator input apparatus;

communicating the desired draft load value to the draft load controller via the vehicle electronic communication system;

operating the tractor to cause the implement to engage the ground thereby creating an actual draft load on the tractor;

generating an engine load value by the at least one engine load controller, wherein the engine load value is determined by an engine control system having at least one digital controller;

generating at least one auxiliary load value in the auxiliary load controller;

communicating the engine load value and the least one auxiliary load value to the draft load controller via a vehicle electronic communications system;

determining by the draft load controller a draft load value based on the engine load and the at least one auxiliary load value determined by at least one auxiliary load digital controller configured to control additional load on the engine other than the draft load, wherein the additional load is produced by at least one of a power take-off of a tractor, a cab air conditioning system or an engine cooling fan;

comparing the actual draft load value to the desired draft load value;

calculating an error signal based on the difference between the actual draft load value and the desired draft load value,

generating an implement position control signal having a value,

communicating the implement position control signal to the implement position actuator;

changing the implement position based on the value of the implement position control signal thereby causing the error signal to be substantially zero and managing a substantially constant draft load on the tractor.

9. The method of claim 8 wherein said draft load controller is a digital controller.

10. The method of claim 9, wherein said vehicle electronic communications system comprises a communication link connecting said at least one engine controller, said at least one auxiliary load controller, and said draft load controller and wherein the draft load control calculates a draft load from the engine load determined from inputs from the engine controller and at least one auxiliary load representing load on the engine other than the draft load and determined form inputs from the at least one auxiliary load controller.

11. In an agricultural tractor for propelling a connected ground-engaging implement, said tractor having an engine for propelling said tractor and said implement, an engine control system for selectively controlling torque and speed of said engine responsive to an operator input, and an operator input apparatus, an implement position actuator for selectively varying position of said connected ground-engaging implement, wherein the improvement comprises:

a digital draft load controller;

at least one digital engine controller in said engine control system;

at least one auxiliary load powered by said engine, power from said engine to said at least one auxiliary load being by at least one auxiliary load controller having at least one digital auxiliary load controller;

a vehicle electronic communication system for sending and receiving signals from said operator input apparatus, said digital draft load controller, said digital engine controller, and said digital auxiliary load controller, wherein said vehicle communication system is a controller area network and comprises a communication link connecting said at least one digital engine controller, said at least one digital auxiliary load controller, and said digital draft load controller; and

said digital draft load controller connected to said vehicle electronic communications system to receive an engine load signal from said digital engine controller and at least one auxiliary load signal from said at least one digital auxiliary load controller, and derive, in accordance with its programming, and send an implement position control signal to said implement position actuator to manage said implement position based on said position control signal whereby a substantially constant draft load is maintained on said tractor; and

wherein said draft load controller, upon receiving said digital engine controller signal and said at least one digital auxiliary load controller signal from said vehicle electronic communication system derives an actual draft load value, the actual draft load value derived using the engine torque, a state of the transmission of the vehicle and significant auxiliary loads placed on the engine other than the draft load, the draft load controller receives said desired draft load value from said vehicle electronic communication system and compares said actual draft load value to said desired draft load value, generates an implement position control signal configured to command the implement to a position such that the difference between the derived actual draft load and desired draft load is reduced.