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Ionospheric delay is one of the main errors in the satellite navigation and positioning system. At present, ionospheric delay correction model and grid ionospheric information are provided to correct the error in BeiDou Navigation Satellite System (BDS). The ionospheric delay correction model is the Klobuchar model with 8 parameters at the geographic latitude for basic navigation. Grid ionospheric information is the ionospheric grid map covering China region for enhanced services. The dual-frequency pseudo-range combination data and ionospheric data from 2013 to 2018 have been used to make comprehensive assessments of the correction performance of BDS Klobuchar model and ionospheric grid information. The average correction rate of ionospheric grid information is about 85%, and the average correction rate of BDS Klobuchar model is about 73%. The correction accuracy of BDS Klobuchar model varies little, and the ionospheric grid information has a single-peak structure. The correction accuracy in summer and autumn is slightly higher than that in winter and spring. Changes in solar activity have a greater impact on BDS Klobuchar model correction bias. Ionospheric grid information owns relatively strong anti-disturbance ability, and BDS Klobuchar model also has a definite anti-disturbance capability compared with the GPS Klobuchar model.

It is critical to improve the yield of rolled products and reduce the energy consumption based on billet limited weight cutting. The effect on billet limited weight by dimensional accuracy of billet image and billet casting speed is analyzed, and the behaviour control architecture of billet limited weight cutting is established. The goals of billet limited weight cutting is decomposed into cutting tasks and cutting actions based on finite-state machine theory. The theoretical weight, the integral weight and the predicted weight as the state switching conditions of behaviour control model, so that the billet limited weight cutting is realized. The model of construction is beneficial for the autonomous behaviour control of billet limited weight cutting.