Abstract: A method for operating a fan system as well as such a fan system. The fan system has a control device having an artificial neural network. The control device controls an electric motor of a backward curved centrifugal fan. The centrifugal fan creates a gas flow that is characterized by an actual flow value, particularly the actual value of a volume flow rate. The actual flow value is not detected by a sensor means, but determined by means of the artificial neural network depending from input variables and based thereon, the electric motor is open loop or closed loop controlled by means of the control device. The motor current and the motor voltage as well as their time-dependent behavior that can be the time derivative (e.g. gradient of first order) or that can be at least one preceding value at a preceding point in time, are provided to an input layer of the artificial neural network.

Abstract: A method for measuring and testing a vehicle frame (15), in particular a commercial vehicle or bus frame, wherein a radiation source and a radiation receiver are arranged in front of the frame (15) and radiation is beamed from the radiation source toward the frame (15) and onto a reflector support (1) having at least one reflector (2, 3, 4, 5). The reflector (2, 3, 4, 5) is assigned to a part of the frame (15), and the radiation is reflected by the reflector (2, 3, 4, 5) to the radiation receiver and a measuring device determines location coordinates of the reflector (2, 3, 4, 5) at different measuring points of the frame part. A substantially non-deformed section (A) of the frame part is ascertained from the resulting measuring points (P) and the variation of the measuring points (P) from the non-deformed section (A) is determined.

Abstract: A method for measuring and testing a vehicle frame (15), in particular a commercial vehicle or bus frame, wherein a radiation source and a radiation receiver are arranged in front of the frame (15) and radiation is beamed from the radiation source toward the frame (15) and onto a reflector support (1) having at least one reflector (2, 3, 4, 5). The reflector (2, 3, 4, 5) is assigned to a part of the frame (15), and the radiation is reflected by the reflector (2, 3, 4, 5) to the radiation receiver and a measuring device determines location coordinates of the reflector (2, 3, 4, 5) at different measuring points of the frame part. A substantially non-deformed section (A) of the frame part is ascertained from the resulting measuring points (P) and the variation of the measuring points (P) from the non-deformed section (A) is determined.