pade (Control Design and Simulation Module, MathScript Function)
Member of the convert class.
Syntax
SysDel = pade(SysCon, order)
SysDel = pade(delay, order)
[num, den] = pade(delay, order)
[A, B, C, D] = pade(delay, order)
Description
Incorporates time delays into a system model using the Pade approximation method, which converts all residuals. You must specify the delay using the set function. You also can use this function to calculate coefficients of numerator and denominator polynomial functions with a specified delay.
Inputs
Name | Description |
SysCon | Specifies a continuous linear time-invariant (LTI) model in transfer function, zero-pole-gain, or state-space form. |
delay | Specifies the delay time, in seconds, to incorporate into the numerator and denominator polynomial functions. |
order | Specifies the order of the Pade approximation polynomial functions. A higher order results in a more accurate approximation of the delay but also increases the order of the resulting model. A large order can make the model too complex to be useful. order is an integer scalar. |
Outputs
Name | Description |
SysDel | Returns an LTI model in transfer function, zero-pole-gain, or state-space form, with delay incorporated. If you specified SysCon as the first input to this function, SysDel is SysCon with delay incorporated. If you specified delay as the first input, SysDel is a system model of pure delay. |
num | Returns the coefficients of a numerator polynomial function with delay incorporated. |
den | Returns the coefficients of a denominator polynomial function with delay incorporated. |
A | Returns an n x n state matrix with delay incorporated, where n is the number of states. A is a real matrix. |
B | Returns the n x m input matrix with delay incorporated, where m is the number of inputs. B is a real matrix. |
C | Returns the r x n output matrix with delay incorporated, where r is the number of outputs. C is a real matrix. |
D | Returns the r x m direct transmission matrix with delay incorporated. D is a real matrix. |
Examples
SysCon = zpk(1, 3.2, 6)SysCon = set(SysCon, 'inputdelay', 6, 'outputdelay', 1.1)
SysDel = pade(SysCon, 2)
delay = 1.2
order = 3
[num, den] = pade(delay, order)