Reliable estimation of longitudinal force and sideslip angle is essential for vehicle stability and active safety control. This paper presents a novel longitudinal force and sideslip angle estimation method for four-wheel independent-drive electric vehicles in which the cascaded multi-Kalman filters are applied. Also, a modified tire model is proposed to improve the accuracy and reliability of sideslip angle estimation. In the design of longitudinal force observer, considering that the longitudinal force is the unknown input of the electric driving wheel model, an expanded electric driving wheel model is presented and the longitudinal force is obtained by a strong tracking filter. Based on the longitudinal force observer, taking into consideration uncertain interferences of the vehicle dynamic model, a sideslip angle estimation method is designed using the robust Kalman filter and a novel modified tire model is proposed to correct the original tire model using the estimation results of longitudinal tire forces. Simulations and experiments were carried out, and effectiveness of the proposed estimation method was verified.

The parish church at Kórnik was founded by Mikołaj Górka – the chancellor of the Poznan Cathedral Chapter, the owner of Kórnik castle, and the founder of the town of Kórnik. The church is an architectural copy of the Holy Virgin Mary in Summo – the collegiate church located by Poznan cathedral, erected in the style of master Brunsberg of Szczecin. It was consecrated in 1437, and it must have been largely finished by that time. It was only a couple of years ago that it was established that it had a tribune above its sacristy, and that together with the latter it had the exterior form of a tower. On the basis of architectural analysis, the author of the article reconstructs the shape of the tribune in detail and proves that it was completed in its entirety and used. He also formulates a thesis that the interior of the tribune combined the functions of a chapel and ceremonial area. The unusual shape of the great arcade, opening the interior of the tribune towards the church chancel, is an indication of a reference to the chapel tribunes in the towers surrounding the chancel of the Poznan cathedral.