Early Control Textbooks in Denmark

This chapter provides a brief review of two of the early control textbooks in Denmark: Automatisk Kantrol and Notes on the Measurements of Dynamic Systems. The development of the field in Denmark dates to 1949 when Jens R. Jensen held a course on Automatisk Kontrol for engineers, organized by the Danish Engineering Association. The lecture notes were the result of developing interest in the area of servomechanisms rapidly followed by industrial demand and research interest in control of machines, industrial mechanisms, and processes. In January 1956, the Danish industry founded the "Servoteknisk Forskningslaboratorium" as an independent research institute funded by industry. With Jens R. Jensen in charge of a few research engineers and a workshop assistant, the small team was busy bringing the latest theoretical developments into practice. Much effort was dedicated to the dynamic modeling of control objects and the measurement of response characteristics. The efforts included equipment to do correlation analysis to measure the dynamic characteristics, for example, of heat exchangers. The second book was used to teach measurement of dynamic characteristics, the area that later developed into system identification. The Notes on the Measurements of Dynamic Systems, Parts I and II show how correlation analysis was done using thermocouple multipliers. A digital correlation machine was subsequently constructed and the seven frequency binary test signal was invented by Jens R. Jensen.