Modeling and Topology Optimization of the Thermal Stability in Laser 4-DOF Measurement Systems

A novel design method based on topology optimization is proposed and demonstrated to enhance thermal stability in laser four-degree-of-freedom (4-DOF) measurement systems against environmental temperature fluctuations. The overall thermal deformation of the measurement systems is calculated by finite element analysis. The thermal errors caused by thermal deformation of workpieces are analyzed and modeled. The workpieces of the 4-DOF measurement systems are designed using topology optimization, resulting in a 50% reduction in thermal deformation. Furthermore, the temperature field of the measurement system is optimized by incorporating thermal insulation materials, and stability experiments are performed on the system both before and after optimization. The stability of the laser beam is improved by 53.9%, 49.0%, 58.0%, and 52.5% in two angular and two straightness directions, respectively. Experimental results demonstrate that the proposed method effectively enhances the stability of the 4-DOF measurement systems and can be applied to improve the thermal stability of other precision instruments.