Optimization of pulse-modulation based ToF imaging systems

This work is dedicated to efficient optimization of pulse-modulated (PM) indirect time-of-flight (iToF) through analytical modeling. Measurements that verify the validity of the model for two generations of CMOS iToF imagers are presented. As convexity is not guaranteed and e.g. eye-safety constraints have points of non-differentiability, the feasibility of Evolutionary Strategy (ES) optimizers was investigated. Compared to alternative non-differentiating global optimizers this has the advantage of offering systematic and random progress capability without the need for phenotype-genotype mapping. A MATLAB implementation is presented that demonstrates convergence of a problem with 6 degrees of freedom (DOF) in less than 100 iterations. Compared to the brute force approach this is an improvement by several orders of magnitude, as there computation time scales exponentially with the number of DOF.