6-DOF Seismic Table Simulation

What is modeled:

* Servovalve dynamics
* Actuator dynamics
* Geometry effects
* Rigid body dynamics in six degrees of freedom
* Approximate physical displacement and velocity limits
* Accumulator bank pressure change with flow

What is not modeled:

* Hydraulic distribution losses and dynamics
* Sensor and conditioner dynamics
* Foundation interaction
* Specimen, table, and bowstring resonances
* Friction
* Exact physical displacement and velocity limits
  (approximate physical limits values are precomputed relative
  to the table origin, yet applied at the center of gravity)
* Exact nonlinear behavior when hitting a physical limit or
  coming out of a physical limit.
