Agricultural spraying equipment boom level control system
A system and method for controlling the level of a moveable first wing in a vehicle mounted spray system. The vehicle mounted spray system comprises of the moveable first wing and a moveable second wing mounted to a common support structure to form a pair of opposed independently moveable wings extending laterally from the vehicle. The method and system comprise a first step of determining an initial control signal for the moveable first wing based on a position of the moveable first wing 210 , then determining a compensating signal; and then controlling the level of the moveable first wing based on the initial control signal and the compensating signal.
1. A method for controlling the level of a moveable first wing in a vehicle mounted spray system that comprises the moveable first wing and a moveable second wing mounted to a common support structure to form a pair of opposed independently moveable wings extending laterally from the vehicle, the method comprising:
a) determining an initial control signal to move the moveable first wing independent of the moveable second wing based on a position of the moveable first wing;
b) determining a compensating signal for the initial control signal wherein the compensating signal is derived independent from the moveable first wing and includes a component dependent upon a position of the moveable second wing and a time delayed control signal output to the moveable second wing; and
c) controlling a level of the moveable first wing independent of the moveable second wing by combining the initial control signal and the compensating signal,
wherein the position of the moveable second wing is defined as a first wing height error,
the first wing height error being a difference between a height of the moveable second wing with respect to the ground and a reference height, and
the time delayed control signal output to the movable second wing is based on the first wing height error.
2. A method as claimed in claim 1 , wherein the component is of the form
K
1
(
D
2
)
=
∑
j
=
1
j
=
N
D
2
,
j
_
×
C
j
,
where D 2 is the control signal output to the moveable second wing, D 2,j is a time delayed control signal for the moveable i second wing for a time delay t j , C j is the jth constant of proportionality and N is the number of time delayed control signals to be combined.
3. A method as claimed in claim 2 , wherein the time delay t 1 is between 0.4 and 0.6 seconds.
4. A method as claimed in claim 2 , wherein N is 1.
5. A method as claimed in claim 1 , wherein the compensating signal further includes a component dependent upon a roll measure of the vehicle.
6. A method as claimed in claim 5 , wherein the roll measure is a roll rate of the vehicle {dot over (θ)}.
7. A method as claimed in claim 6 , wherein the component dependent upon a roll measure of the vehicle is of the form K 1 ({dot over (θ)})={dot over (θ)}×R where R is a roll rate constant of proportionality.
8. A method as claimed in claim 1 , wherein the position of the moveable first wing is defined as a second wing height error, the second wing height error being a difference between a height of the first wing with respect to the ground and a reference height.
9. A method as claimed in claim 8 , wherein the initial control signal for the moveable first wing includes a component H 1 (Δh 1 )=Δh 1 ×G, where Δh 1 is the second wing height error, and G is a constant termed the proportional gain.
10. A method for controlling the level of a moveable first wing and a moveable second wing in a vehicle mounted spray system that comprises the moveable first wing and the moveable second wing mounted to a common support structure to form a pair of opposed independently moveable wings extending laterally from the vehicle, the method comprising:
a) determining initial control signals to move each moveable wing independent of the other moveable wing based on the respective positions of each moveable wing;
b) determining respective compensating signals for each moveable wing wherein the respective compensating signal for each moveable wing is derived independent from the respective moveable wing and includes a component dependent upon the position of the other moveable wing and a time delayed control signal output to the other moveable wing, and compensates the initial control signal of the respective moveable wing,
wherein the position of the other moveable wing is defined as a wing height error of the other moveable wing,
the wing height error of the other movable wing being a difference between a height of the other moveable wing and a reference height, and
the time delayed control signal output to the other moveable wing is based on the wing height error of the other moveable wing; and
c) controlling the level of each moveable wing independent of the other moveable wing by combining the respective initial control signals and the respective compensating signals.
11. A method as claimed in claim 10 , wherein the respective compensating signal for each wing further includes a component dependent upon a roll measure of the vehicle.
12. A method as claimed in claim 11 , wherein the roll measure is the roll rate of the vehicle {dot over (θ)}.
13. A method as claimed in claim 12 , wherein a component for the first moveable wing is of the form K 1 ({dot over (θ)})={dot over (θ)}×R and a component for the second moveable wing is of the form K 2 ({dot over (θ)})={dot over (θ)}×R, where R is the roll rate constant of proportionality.
14. A system for controlling the level of a moveable first wing in a vehicle mounted spray system that comprises the moveable first wing and a moveable second wing mounted to a common support structure to form a pair of opposed independently moveable wings extending laterally from the vehicle, the system comprising:
a) means for determining an initial control signal to move the moveable first wing independent of the moveable second wing based on a position of the moveable first wing;
b) means for determining a compensating signal for the initial control signal wherein the compensating signal is derived independent from the moveable first wing and includes a component dependent upon a position of the moveable second wing and a time delayed control signal output to the moveable second wing; and
c) means for controlling a level of the moveable first wing independent of the moveable second wing by combining the initial control signal and the compensating signal,
wherein the position of the moveable second wing is defined as a first wing height error,
the first wing height error being a difference between a height of the second wing with respect to the ground and a reference height, and
the time delayed control signal output to the movable second wing is based on the first wing height error.
15. A system for controlling the level of a moveable first wing and a moveable second wing in a vehicle mounted spray system that comprises the moveable first wing and the moveable second wing mounted to a common support structure to form a pair of opposed independently moveable wings extending laterally from the vehicle, the system comprising:
a) means for determining initial control signals to move each moveable wing independent of the other moveable wing based on the respective positions of each moveable wing;
b) means for determining respective compensating signals for each moveable wing wherein the respective compensating signal for each moveable wing is derived independent from the respective moveable wing and includes a component dependent upon the position of the other moveable wing and a time delayed control signal output to the other moveable wing, and compensates the initial control signal of the respective moveable wing,
wherein the position of the other moveable wing is defined as a wing height error of the other moveable wing,
the wing height error of the other movable wing being a difference between a height of the other moveable wing and a reference height, and
the time delayed control signal output to the other moveable wing based on the wing height error of the other moveable wing; and
c) means for controlling the level of each moveable wing independent of the other moveable wing by combining the respective initial control signals and the respective compensating signals.