For the construction of the mobile robot system, it is necessary to determine a lot of parameters like the feedback gain and the clip parameters of artificial saturation. And it is difficult to decide suitable parameters by analytical technique because of its non-linearity and complexity. In this paper, we propose the method of the mobile robot control system parameter design by a numerical simulation and heuristic optimization using the enough computer power. We describe the model of the system as iterative numerical calculation instead of analytical time function. This model can suit the real control system, and it is straightforward to be built. And we show the experimental results of the automatically decided feedback gains by using proposed method for the linear feedback trajectory tracking controller of the small-sized autonomous mobile robot system, which runs in relatively high speed up to 5 meters per second as an example.