Abstract: A system for measuring optical detector linearity according to the present invention employs a laser source that illuminates an integrating sphere. The sphere randomizes the laser signal phase and produces a uniform intensity over the sphere output. A collimator expands the sphere output for entry into an interferometer, where the incident optical energy is amplitude modulated in a sinusoidal fashion by a linear mechanical mirror movement. Optical band filters eliminate significant harmonic content being present on a pre-detected optical signal. Sampling of the detected signal energy is performed synchronous to the mechanical mirror position to assure sinusoidal response. The sampled signals are processed to separately determine signal harmonic components attributed to detector non-linearity and multiple laser reflections within the system. The system utilizes at least two measurements at two different laser intensities.

Abstract: A motor control method and apparatus produce rapid, point-to-point movement while minimizing settling time and peak power consumption in a servo-control system with a periodic input. Rapid open-loop movement is combined with tuning of the open-loop input based on position and velocity of the output when the loop is closed. Iterative learning control is used to adjust open-loop commands in subsequent cycles to reduce residual vibrations and quickly reach the desired final position. The apparatus and method can be used in motion control applications requiring rapid, periodic, point-to-point movement, such as weather satellite servo systems with a periodic input containing multiple step responses within each period.