A Complex Convolution Kernel-Based Optical Displacement Sensor

During the last decade, a variety of optical displacement measurement techniques have been developed, commercialized and widely used. This paper presents a new type of optical displacement sensor that improves on the prior art with higher sub-pixel resolution, better accuracy, and better computation efficiency. The Complex Convolution Kernel-Based Optical Sensor (KBOS) developed in this paper leverages the phase-magnitude representation of a complex valued kernel function to achieve a superior optical displacement sensor for 2D motion measurements. The sensor's performance and properties are quantified in terms of its ability to compute the marker motions. Evaluation of this metric will explain how the sensor is able to achieve superior performance over the state of the art. The design is then validated with a set of experiments over a range of operating conditions to demonstrate the effectiveness of the approach over other existing displacement measurement techniques. Finally, the sensor's capability is compared qualitatively against other state of the art optical displacement sensors found in the literature. The sensor is shown to possess a subpixel resolution of between 1/100 and 1/2500 of a pixel depending upon spatial sampling density. The sensors dynamic range was investigated and shown to be only limited by the camera sampling speeds.