Using robots for very wide operating ranges or for heavy loads requires taking the elastic deformations of the links into account. A recent model independent approach for damping the vibrations of a multilink flexible robot is the control concept of the virtual spring-damper, in which the actuators are controlled to act like spring-damper-systems. To improve performance requirements, an independent substitution model for the arm is introduced, because obtaining an accurate analytical model for multilink flexible robots involves considerable problems. This paper deals with a substitution model which describes the essential dynamic and vibration behavior of the flexible link. To avoid obtaining an analytical model, the substitution parameters have to be identified by system measurements. Therefore the position of the end effector, however, cannot be measured.