Delta approach robust controller for constant turning force regulation

The adaptive implementation of a new robust controller for the constant turning-force regulation problem under varying cutting conditions is presented. The discrete-control structure is based on a variable state feedback regulator obtained using the delta approach optimal control theory. The controller scheme is robust in the presence of cutting process nonlinearities and parametric disturbances. The proposed adaptive scheme uses an estimation and controller algorithm including a prior knowledge of the system. A robustness analysis shows the effectiveness of the proposed solution. Simulations and experimental results obtained with an industrial lathe show the robustness of the proposed solution. (C) 1999 Elsevier Science Ltd. All rights reserved.