Parameter Estimation of a Laser Measurement Device Using Particle Swarm Optimization

The two-dimensional object’s position or object’s edge can be estimated from its multi-exposure shadow projection. This can be done using two bare Laser diodes projecting the object’s edge onto a CCD or CMOS sensor without the need of any additional optical elements such as collimation lenses. For simple triangulation methods, Sensor- and laser diode position play a very important role. The overall accuracy is mostly determined by the uncertainty of that parameters. This paper presents a possible approach to determine that parameters. Since deterministic methods suffer from badly shaped error functions, stochastic methods can deliver very good results, ending up in the global optimum. When using particle swarm optimization, it could be shown, that the remaining residual error of an estimated projected edge position can be significantly reduced. This error immediately effects the overall object’s position estimation accuracy, which can also be increased, in case the geometrical system parameters were determined using particle swarm optimization.