What is a quasi hardware in the loop simulator?
A quasi-hardware in the loop simulator is one where the autopilot software runs on the autopilot software and the simulator runs on a separate computer (usually a windows PC). Sensor data and control surface deflection information are exchanged between the autopilot and the simulator via some communications mechanism-usually a serial port or CAN bus. The autopilot is not running exactly the same code as it would normally execute because, rather than reading values from its various sensors (gyros, accelerometers, pressure sensors), it is reading this data from the serial port/CAN bus. The result is that this type of simulation, while valuable, it is imperfect due to the fact that the communication mechanism introduces delays that wouldn’t be present in the real autopilot and because the autopilot executes different code than it does in flight.
