Limiting servo motor torque gradients with near minimum time repositioning

The theory for directly limiting motor torque gradient (jerk) using a modified bang-bang controller is developed. Modified band-bang is a nonlinear control system which applies to minimum time solutions for simple second-order systems. The results are verified using simulation and experimentation. The techniques are applied to the ramming mechanism of a large caliber tank autoloader with excellent results. An immediate consequence is a significant increase in the life of a critical rammer component through the use of a limited torque gradient. This is achieved through the resultant lowering of fatigue cycling levels that are initially caused by sampling rate encoder feedback noise and other nonlinear effects such as backlash