Plant control system
AssigneeToyota Jidosha Kabushiki Kaisha
InventorHayato Nakada
Life of this patent
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Abstract
A plant control system comprises a feedback controller 5 configured to determine a control input of a plant 6 so that one control output of the plant approaches a target value, a provisional target value calculating part 2 configured to calculate a provisional target value based on a predetermined parameter of the plant, and a reference governor 3 configured to perform a minimum value search of an object function by updating a corrected target value to thereby derive the target value from the provisional target value. The reference governor is configured to update the corrected target value only between r−0.5Rr and “r”. Rr is a value of a partial differential for the corrected target value “w” of the object function when the corrected target value “w” is the provisional target value “r”.
Claims10
A plant control system comprising:
- a controller configured to:
- determine a control input of a plant so that one control output of the plant approaches a target value;
- calculate a provisional target value based on a predetermined parameter of the plant;
- perform a minimum value search of an object function by updating a corrected target value to thereby derive the target value from the provisional target value, wherein
- the object function is defined by at least one of the following two equations:
- J
-
- (
- w
- )
- =
- (
- r
- -
- w
- )
- 2
- +
- ρ
-
- ∑
- k
- =
- 1
- N
-
-
- max
-
- {
- y
- k
- -
- y
- up
- ,
- 0
- }
- J
-
- (
- w
- )
- =
- (
- r
- -
- w
- )
- 2
- +
- ρ
-
- ∑
- k
- =
- 1
- N
-
-
- max
-
- {
- y
- low
- -
- y
- k
- ,
- 0
- }
- where “r” is the provisional target value, “w” is the corrected target value, p is a weighting coefficient, “k” is a time step, yk is a future predicted value of the control output at the time step k, yup is an upper limit value of the control output, ylow is a lower limit value of the control output, and N is a number of prediction steps;
- calculate the future predicted value of the control output by the following formula:
- yk+1=Ayk+Bw,
- where A and B are predetermined constants;
- and
- update the corrected target value only between r−0.5Rr and “r”, where Rr is a value of a partial differential for the corrected target value “w” of the object function when the corrected target value “w” is the provisional target value “r”.
Dependencies are inferred from the claim text.