In systems and control theory, the double integrator is a canonical example of a second-order control system.
[1] It models the dynamics of a simple mass in one-dimensional space under the effect of a time-varying force input
The differential equations which represent a double integrator are: where both
Let us now represent this in state space form with the vector
In this representation, it is clear that the control input
In the scalar form, the control input is the second derivative of the output
The normalized state space model of a double integrator takes the form According to this model, the input
Taking the Laplace transform of the state space input-output equation, we see that the transfer function of the double integrator is given by Using the differential equations dependent on