Patent Document ID: 7620462
Application ID: 11572778
Patent Flag: 1

Claim One:
1. A designing device of a robust digital controller, wherein said designing device realizes an integral type control system that is obtained by equivalently converting a system and is connected with a control target satisfying the following state equation 5 when an input h, a controlled variable y, a first equivalent disturbance q v , a second equivalent disturbance q v and a time-lag ξ 1 are given respectively: 
 x d ( k+ 1)= A d x d ( k )+ B d h ( k ) 
 y ( k )= C d x d ( k )+ q y ( k ) 
 where x d =[xξ] T Equation 5 wherein aid system converted is formed by approximating a transfer function W ry (z) between a target value r and said controlled variable y when a state feedback rule and a feedforward rule are applied to said control target to determine a quadratic approximate model transfer function W m (z) shown in the following equation 6: W ry = ⁢ ( 1 + H 1 ) ⁢ ( 1 + H 2 ) ⁢ ( 1 + H 3 ) ⁢ ( z - n ⁢ ⁢ 1 ) ⁢ ( z - n ⁢ ⁢ 2 ) ⁢ ( z + H 4 ) ( 1 - n ⁢ ⁢ 1 ) ⁢ ( 1 - n ⁢ ⁢ 2 ) ⁢ ( z + H 1 ) ⁢ ( z + H 2 ) ⁢ ( z + H 3 ) ⁢ ( z + H 4 ) ≈ ⁢ W m ⁡ ( z ) = ( 1 + H 1 ) ( z + H 1 ) Equation ⁢ ⁢ 6 (where z=exp (jωt); n 0 , n 1 , n 2 are zeros; and H 1 , H 2 , H 3 , H 4 are poles.) and then by combining the model transfer function W m (z), an inverse function W m (z) −1 of said model transfer function W m (z) and a dynamic compensator K(z) with characteristics, shown in the equation 7, for realizing the inverse function W m (z) −1 : k ⁡ ( z ) = k z z - 1 + k z Equation ⁢ ⁢ 7 said integral type control system, further comprising: a first feedback means configured to output a product of said controlled variable y and parameter k 1 , a second feedback means configured to output a product of said controlled variable y and parameter k 2 , a third feedback means configured to output a product of a first time-lag output ξ 1 and parameter k 3 , a fourth feedback configured to output a product of a second time-lag output ξ 2 and parameter k 4 , a fifth feedback means configured to output a product of a third time-lag output ξ 3 and a parameter k 5 , a sixth feedback means configured to output a product of said controlled variable y and parameter k 6 , a first arithmetic means configured to calculate a difference between said controlled variable y and said target value r, an integrating means configured to integrate the calculated value from the first arithmetic means to covert the integrated value into a fourth time-lag output ξ 4 , a first accumulating means configured to output a product of a fourth time-lag output ξ 4 from said integrating means and parameter k in , a first adding means configured to add an output from said first accumulating means, an output from said fifth feedback means and an output from said sixth feedback means, a first time-lag means configured to output said third time-lag output ξ 3 that has made the added result from said first adding means undergo a sampling time-lag, a second accumulating means configured to output a product of a third time-lag output ξ 3 and a parameter k i , a third accumulating means configured to output a product of a third time-lag output ξ 3 and a parameter k iz , a second adding means configured to add said second equivalent disturbance q v , an output from said second accumulating means, an output from said first feedback means, an output from said third feedback means and an output from said fourth feedback means, a second time-lag means configured to output said second time-lag output ξ 2 that has made the added result from said second adding means undergo a sampling time-lag, a third adding means configured to add an output from said second time-lag means, an output from said third accumulating means and an output from said second feedback means to produce an input h to said control target, wherein each parameter is expressed as equation 8 when said state feedback rule F=[F(1,1) F(1,2) F(1,3) F(1,4)] and said feedforward rule G have been applied: k 1 = - F ⁡ ( 1 , 1 ) - F ⁡ ( 1 , 2 ) ⁢ FF ⁡ ( 1 , 1 ) + ( ( - F ⁡ ( 1 , 4 ) - F ⁡ ( 1 , 2 ) ⁢ FF ⁡ ( 1 , 4 ) ) ⁢ ( - F ⁡ ( 1 , 2 ) / FF ⁡ ( 1 , 2 ) ) ) - ( GH ⁢ ⁢ 4 + GF z ) ⁢ ( ( 1 - n 0 ) ⁢ k z / ( ( 1 + H ⁢ ⁢ 1 ) ⁢ ( 1 + H ⁢ ⁢ 2 ) ) ) ⁢ ⁢ k 2 = - F ⁡ ( 1 , 2 ) / FF ⁡ ( 1 , 2 ) - G ⁢ ( ( 1 - n 0 ) ⁢ k z / ( ( 1 + H ⁢ ⁢ 1 ) ⁢ ( 1 + H ⁢ ⁢ 2 ) ) ) ⁢ ⁢ ⁢ k 3 = - F ⁡ ( 1 , 3 ) - F ⁡ ( 1 , 2 ) ⁢ ( FF ⁡ ( 1 , 3 ) ) ⁢ ⁢ ⁢ k 4 = F z ⁢ ⁢ ⁢ k 5 = n 0 ⁢ ⁢ k 6 = - ( k z ⁡ ( 1 - n 0 ) ⁢ ( 1 + H ⁢ ⁢ 1 + H ⁢ ⁢ 2 ) + n 0 ⁡ ( 1 - n 0 ) ⁢ k z ) / ( ( 1 + H ⁢ ⁢ 1 ) * ( 1 + H ⁢ ⁢ 2 ) ) ⁢ ⁢ ⁢ k i = GH ⁢ ⁢ 4 + GF z ⁢ ⁢ ⁢ k iz = G ⁢ ⁢ ⁢ k i ⁢ ⁢ n = k z ⁢ ( 1 - n 0 ) ⁢ ⁢ ⁢ FF ⁡ ( 1 , 1 ) = - A d ⁡ ( 1 , 1 ) / A d ⁢ ( 1 , 2 ) ⁢ ⁢ ⁢ FF ⁡ ( 1 , 2 ) = A d ⁢ ( 1 , 2 ) ⁢ ⁢ ⁢ FF ⁡ ( 1 , 3 ) = - A d ⁡ ( 1 , 3 ) / A d ⁢ ( 1 , 2 ) ⁢ ⁢ ⁢ FF ⁡ ( 1 , 4 ) = - B d ⁡ ( 1 , 1 ) / A d ⁢ ( 1 , 2 ) ⁢ ⁢ ⁢ F z = - F ⁡ ( 1 , 4 ) - F ⁡ ( 1 , 2 ) ⁢ FF ⁡ ( 1 , 4 ) Equation ⁢ ⁢ 8 wherein said designing device comprises: a parameter specifying means configured to specify pole values H 1 , H 2 , zero values n 1 , n 2 of said control target in a discrete-time and parameter values p 1 , p 2 , p 3 , k z , an undetermined value calculating means configured to calculate each of undetermined values of a zero n 0 and pole H 3 from the following relational equation shown in equation 9 by using each of the pole values specified by said parameter specifying means: ( - n 1 ⁡ ( - n 0 ) - n 2 ⁢ ( - n 0 ) + H 3 ⁢ n 1 ⁢ n 2 - n 2 ⁢ H 3 - H 3 ⁢ n 1 + k z ⁡ ( - n 0 ) ⁢ H 3 + n 1 ⁢ n 2 ⁡ ( - n 0 ) + k z - 1 - n 1 ⁢ n 2 + k z ⁢ ( - n 0 ) + H 3 + n 1 + n 2 + k z ⁢ H 3 + ( - n 0 ) ) / ( 1 - n 2 - n 1 + n 1 ⁢ n 2 ) = - ( p ⁢ ⁢ 1 + p ⁢ ⁢ 3 + p ⁢ ⁢ 2 ) Equation ⁢ ⁢ 9 ( - k z ⁢ n 1 ⁡ ( - n 0 ) - k z ⁢ n 2 ⁡ ( - n 0 ) ⁢ H 3 - H 3 ⁢ n 1 ⁢ n 2 + ( - n 0 ) ⁢ H 3 + n 1 ⁢ n 2 ⁡ ( - n 0 ) ⁢ H 3 + H 3 ⁢ n 1 - n 2 ⁡ ( - n 0 ) ⁢ H 3 - H 3 - k z ⁢ n 1 ⁢ H 3 - k z ⁢ n 2 ⁢ H 3 - k z ⁢ n 2 ⁡ ( - n 0 ) - k z ⁢ n 1 - k z ⁢ n 2 - n 1 ⁡ ( - n 0 ) ⁢ H 3 - n 1 ⁢ n 2 ⁡ ( - n 0 ) + n 2 ⁡ ( - n 0 ) + n 2 ⁢ H 3 + n 1 ⁡ ( - n 0 ) - ( - n 0 ) - k z ⁢ n 1 ⁡ ( - n 0 ) ⁢ H 3 ) / ( 1 - n 2 - n 1 + n 1 ⁢ n 2 ) = p ⁢ ⁢ 1 ⁢ p ⁢ ⁢ 3 + p ⁢ ⁢ 1 ⁢ p ⁢ ⁢ 2 + p ⁢ ⁢ 2 ⁢ p ⁢ ⁢ 3 ( k z ⁢ n 1 ⁢ n 2 ⁡ ( - n 0 ) - ( - n 0 ) ⁢ H 3 + k z ⁢ H 3 ⁢ n 1 ⁢ n 2 + k z ⁢ n 1 ⁢ n 2 ⁡ ( - n 0 ) ⁢ H 3 + n 2 ⁡ ( - n 0 ) ⁢ H 3 + n 1 ⁡ ( - n 0 ) ⁢ H 3 - n 1 ⁢ n 2 ⁡ ( - n 0 ) ⁢ H 3 + k z ⁢ n 1 ⁢ n 2 ) / ( 1 - n 2 - n 1 + n 1 ⁢ n 2 ) = ⁢ - p ⁢ ⁢ 1 ⁢ p ⁢ ⁢ 2 ⁢ p ⁢ ⁢ 3 a controller parameter determining means configured to calculate each of parameter values k 1 , k 2 , k 3 , k 4 , k 5 , k 6 , k i , k iz , k in that constitute said integral type control system by using each of the undetermined values from said undetermined value calculating means; and a controller parameter outputting means configured to output each of the parameter values calculated by said controller parameter determining means to said robust digital controller.