Optimal design of loop bandwidth in GPS/INS deeply integration

The typical tracking loops of the GPS/INS deeply integration are unable to track the signals under high dynamic environments. The crux of the integrated system performance is the low-order phase-locked loops (PLL). Once the environmental dynamics exceed a threshold, the tracking loops will lose the assistance of GPS. The conflict between the ability to track the signal and improving PLL tracking performance should be compromised in PLL design. Aiming at this issue, the design of loop bandwidth is vitally important in the GPS/INS integrated system design. To achieve the successful performance, this paper presents the deeply integration tracking loop design based on a third-order PLL, also included is the stability analysis of the tracking loop. Experimental result shows that the bandwidth of such type of tracking loops could be lower than 3Hz.