Novel Sensory Tool Holder Design and Optimization for Multiaxis Cutting Force Sensing in Manufacturing

Multiaxis cutting force sensors enable smart process control and tool condition monitoring in manufacturing; they allow the detection of workpiece damage and suboptimal surface finish, which can arise from tool wear. Existing methods require complex structure modifications to enhance sensor sensitivity, leading to weakened processing performance and expensive customization costs. This article describes the mechanical design and optimization of a sensory tool holder with embedded piezoelectric sensors in standard tool holders. The design has an almost identical rigidity to that of a regular tool holder. We developed a high-fidelity sensing model by multiaxis piezoelectricity and stress analysis, and optimize the sensor locations and orientations to achieve high sensitivity, accuracy, and cross-axis decoupling in specific directions. Static tests indicated that under optimized parameter configurations, the designed tool holder achieved a maximum cross-coupling error of approximately 4.6%, only half of existing researches; it also demonstrated better performance in sensitivity, linearity, hysteresis, and repeatability. The proposed optimal design was verified by the high fidelity model to have a maximum sensitivity error of only 5.34%, confirming its applicability for sensor embedding optimization in various types of standard tool holders without requiring structure modification.