Track jump scheme using internal state manipulation in optical disc drives

Track jump control is a random access strategy applied to short distance movement less than 10 tracks. The most common track jump scheme is a bang-bang control of a kick and brake manner. In a conventional track jump scheme, a track-following controller is turned off during kick and brake periods, and restarted at a target track for track pull-in. The inevitable controller switching is accompanied by undesirable transient response due to non-zero initial condition, and overshoot in the transient response is a crucial factor regarding track pull-in stability. In this paper, a new track jump control scheme without controller switching is proposed for enhancing track jump stability. Instead of control switching, internal states of a track-following controller are artificially manipulated for kick and brake actions in a digital control environment. Experimental results are provided in comparison with conventional track jumps.