Discrete time nonlinear system

How can i develop this discrete-time nonlinear system in simulink?

[x]=[0.01x1 - x2; x1 - 0.003x2^2]

[Fangjun Jiang]

Do you mean?

dx1/dt=0.01*x1-x2;

dx2/dt=x1-0.003*x2^2;

Answer 1

[Fangjun Jiang]

Grab an Integrator block, if the input is dx1/dt, then the output is x1. Do the same for x2 and then you have all you need to build the equation. x2^2 is the same as x2*x2.

You don't seem to have any inputs, so set the initial condition of the Integrator blocks to specify the initial value of x1 and x2 and then run the simulation to see the dynamics.

[dab483]

it is a discrete system. so can i just put the ZoH after i develop those model suggested?

[Fangjun Jiang]

The equation you gave is a continuous system, not a discrete system. A discrete system is typically described as x(k+1)=x(k)+....

c2d() can be used to convert continuous models to discrete time.

It sounds like you need to understand your problem better.

[dab483]

sorry.it is my mistakes. i type it wrongly. it suppose

x1(k+1)=0.01*x1(k)-x2(k);

x2(k+1)=x1(k)-0.003*x2^2(k);

[Fangjun Jiang]

Then replace the Integrator block with the Unit Delay (1/Z) block. The input is x(k+1), the output is x(k).