- Is the outward force on the flyballs really 'centrifugal force'?
- In the rotating reference frame of the governor, we describe the outward force felt by the flyballs as centrifugal force—a fictitious or inertial force. From an inertial (stationary) frame, the balls are simply undergoing centripetal acceleration inward, provided by the tension in the arms. Both perspectives are valid for analysis, but the rotating frame view makes the governor's operation intuitive.
- Why doesn't the governor hold the speed perfectly constant?
- A simple Watt governor provides proportional control, meaning the corrective action (throttle movement) is proportional to the speed error. It cannot eliminate error entirely; it only reduces it to a steady-state value called 'droop.' For perfect constant speed, an integral control action (like that in a later governor design) is needed to eliminate this residual error.
- What real-world systems use principles like the Watt governor?
- The fundamental feedback principle is ubiquitous. Modern applications include cruise control in cars, thermostats for temperature regulation, and electronic speed governors in generators and engines. While the mechanical flyball governor is largely historical, its conceptual legacy is the foundation of all automatic control systems.
- What key simplification does this schematic model make?
- This model assumes an ideal, frictionless linkage and an instantaneous effect of sleeve position on engine speed. In reality, friction causes hysteresis (the speed for rising balls differs from that for falling balls), and the engine's response to throttle changes has a delay. These factors would cause oscillation or inaccuracy in a real device.