Development of active laser reflector for alignment and monitoring of large-scale scientific devices

As large-scale scientific devices like particle accelerators and tokamaks become bigger and more complex, efficient measurements are needed for these devices. At present, when laser trackers are used to measure these devices, manually rotating reflectors is needed in many circumstances, but it's inefficient and it's inappropriate to be used in the areas where human can't approach. To solve the problem, we designed an active laser reflector, which can rotate to a target angle position controlled by a host computer software. We designed a fixture to embed and clamp a spherically mounted retro-reflector (SMR). And two custom-designed motors are used to drive the SMR to rotate horizontally and vertically respectively. The shaft of the motor has a flange to match another flange on the load, which can reduce the coaxiality error between them. The motor control system consists of two motor controllers and a host computer software, and they communicate through WIFI. We made a prototype of the active laser reflector based on the design scheme and measured the offset of the SMR center, which is around +/- 0.23 mm. The active laser reflector we designed can increase the measuring and monitoring efficiency for large-scale scientific devices.