nlss (NGMV Control Toolbox)

NGMV Control Toolbox

nlss

Nonlinear state-space system creator: Static + NLSS + Static

Syntax

NLSYS = NLSS(DIM,X0,XEQ,YEQ{,TS,PARAM})
NLSYS = NLSS(DIM,X0,XEQ,YEQ,INFUN,OUTFUN{,TS,PARAM})

Description

NLSYS = NLSS(DIM,X0,XEQ,YEQ,INFUN,OUTFUN) creates a sandwich system which consists of a nonlinear state-space model structure in between two static mappings, as in the figure below:

The resulting structure NLSYS is meant for use with the NLSS System Simulink block available in the NGMV Toolbox (masked s-function nlsfun).

The meaning of the input arguments is as follows:

Argument	Description
`DIM`	dimension vector `[Nxc,Nxd,Ny,Nu,DFT]`
`Nxc`	number of continuous states
`Nxd`	number of discrete states
`Ny`	number of outputs
`Nu`	number of inputs
`DFT`	Direct FeedThrough flag (1 or 0)
`X0`	vector of initial states (set to `[]` for static systems)
`XEQ`	RHS of the state equation (continuous or discrete) entered as a string (set to `[]` for static systems)
`YEQ`	RHS of the output equation
`INFUN`	Static input function
`OUTFUN`	Static output function
`TS`	Sample time in seconds (discrete-time models); if not specified, set to -1 by default.
`PARAM`	structure containing parameter names and values used in `XEQ` and `YEQ`. It can be omitted if no such parameters used.

Example

DIM = [0 1 1 1 0]; % SISO 1st order system

X0 = 0; % initial state

XEQ = 'x^2 + u'; % state equation

YEQ = 'sin(omega*x)+u'; % output equation

INFUN = 'atan(u)'; % static input function

 OUTFUN = 'u'; % static output function

 PARAM.omega = 0.1; % define the parameter

 NLSYS = NLSS(DIM,X0,XEQ,YEQ,INFUN,OUTFUN,PARAM)

See Also

nlssdiag

ngmvss

nlssdiag