In industrial papermaking equipment, the calender rolls must be precisely controlled to achieve the right degree of smoothness and glossiness in the paper. Typically, roll positions must be maintained within a tolerance of 0.1 millimeters, and the pressure at the nip—the line of contact between rolls—must be within 0.2 bar of its set value.
Using Model-Based Design, Metso developed a digital hydraulic system that meets these requirements, consumes 98% less energy, requires less floor space, and is more reliable than the proportional hydraulic systems traditionally used for nip control.
“Model-Based Design with MATLAB and Simulink was instrumental in helping us reduce costs and improve quality because it enabled us to test and tune a complex controller design via simulation, rapidly implement a real-time prototyping system, and generate code for a production industrial controller PLC,” says Kari Leminen, general manager of automation technology at Metso.