Optimal Infeed Control for Accelerated Spark-Out in Plunge Grinding

An optimal infeed control policy is proposed to minimize the cycle time in cylindrical plunge grinding. As compared with conventional infeed control consisting of roughing followed by spark-out, the proposed infeed control policy accelerates the spark-out by reducing the time required to recover the accumulated elastic deflection in the system and to reduce the infeed velocity to its final required value. This optimal infeed control policy is particularly advantageous for grinding systems having a long characteristic time constant. A practial method is described for implementing the optimal infeed control policy based upon direct measurement of the radial allowance remaining on the workpiece.