The vertical reference system being considered utilizes a two-degree-of-freedom gyroscope configured as a vertical gyro. Each
gimbal erection circuit forms a second-order feedback control system.
Gyros are susceptable to a number of error sources. In view
of the closed loop application being considered, all error sources are
of negligible consequence...
Among the many safety hazards facing chainsaw operators, the phenomenon known as kickback is the most dangerous. Kickback occurs when the chain at the tip of the chainsaw is caused to stop abruptly, and transfers the energy of the cutting chain to motion of the saw. The saw will rotate...