Matched Trajectory Feedback Control of Print Actuator
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
Using an electronically programmable feedback controller to match the trajectory of a moving coil actuator to nominal trajectory, both on the impact stroke and the rebound, provides optimum print hammer trajectory with optimum repetition rate. The coil energization profile is adjusted through feedback to provide a trajectory which matches the nominal trajectory, and in which acceleration changes are kept to a minimum by smoothing the breakpoints of the trajectory. The return kinetic energy brings the hammer back to rest by matching the natural bounce motion of the hammer with the selected reference trajectory. Different profiles are available for different character sets or different paper. Fig. 1 illustrates the principle of feedback control.