Sensor noise

In order to study the performance of the algorithm in the presence of noise, zero mean Gaussian noise is added to the gas sensor readings as

where, F(x_i(t)) is the actual gas concentration, r(0; o)(t) is zero mean Gaussian noise with a standard deviation of o and C(x_i(t)) is the concentration measured by the gas sensor. The glowworms were then placed in a line. With a source at (-2; 0) the time for convergence was noted for different values of o. The figure below shows the effect of noise on the algorithm. The algorithm is found to be robust even for practically high noise levels. This robustness can be attributed to the luciferin update mechanism of the GSO algorithm which considers only the maximum concentration measured in the last Nmem seconds.