###### Abstract  
Drying various materials constitutes an essential component of several industrial processes, e.g., paper production. Typically, rotating cylinders heated internally by water steam are used for drying tape-shaped material in paper-making machines. Such an approach remains very energy-consuming, while the whole process is expensive and in conflict with the global policy of reducing energy consumption in heavy industry. One promising alternative method of drying fibrous tapes is the induction heating of drying cylinders. In this paper, we propose a drying system based on a set of inductors (electromagnetic field sources) that generate energy in the mantle of the cylinder and dry the running tape. By enabling the movement of the inductors, the system provides a high level of flexibility in terms of reacting to the varying humidity of the tape. Additionally, imaging the temperature field on the cylinder surface provides a supplementary source of information, enabling the temperature profile to be controlled. Two types of humidity control systems, a one-loop feedback control and a cascade control, were designed and analyzed. Simulation analysis and experimental verification performed using a semi-industrial setup proves that using the proposed cascade control ensures more than 30% faster response of the whole dryness control system. d 2021 23 December 2021 28  
new designs of inductors which generate the dominant component of the electromagnetic field transverse to the charge plane are able to heat moving objects much larger than the inductors themselves, including rotating drying cylinders. This type of inductor is particularly well suited to automatic power control, whereby thermal energy can be flexibly generated in various areas of the drying cylinder, depending on the different levels of humidity in the tape [11]. Since, in drying devices based on drying rollers, the change in humidity is strongly related to changes to the temperature on the surface of the drying roller [12], it can be assumed that by controlling the temperature profile of the drying roller it will be possible to shape the dryness profile of the tape. The temperature profile can be monitored using, for example, a set of thermocouple elements [13; 14]. However, work on temperature control is currently focused on monitoring not only temperature profiles but also their two-dimensional distributions [15; 16; 17; 18], notably using thermal imaging cameras [19; 20; 21; 22]. To control the temperature profile, it is possible to use both classic control methods [23; 24; 25], methods based on artificial intelligence, e.g., Fuzzy Logic [26] or Neural Networks [27], and methods dedicated to specific applications [28; 29]. The classical PID-type method of control is used to control dryness [30]. In this paper, a holistic approach to the issue of drying fibrous tape is proposed, consisting of a numerical analysis of the induction heating of a drying cylinder, temperature profile control at the cylinder surface, and an automated drying process. The numerical analysis was based on Finite Element Method (FEM) which was implemented in commercial software under the name Flux 2D/3D made by Cedrat Corp. France. Those simulations covered the coupled electromagnetic and thermal calculations, taking into account the non-linear material properties of the calculation areas. Based on those calculations, the dynamics characteristic of heating a rotating cylinder and the appropriate transmittance models of study system were determined. The proposed method of modeling dryness control uses the surface temperature of the cylinder as an auxiliary signal. This is more effective than classic control methods because it allows for faster humidity control. The results of the numerical analysis were confirmed by a series of experiments on a real semi-industrial system. The paper is organized as follows.