Patent ID: 6993435

Claim:
A method for the automatic determination of the diameter of a round disk-like tool driven by a motor such as a saw blade for an automatic wall saw, comprising the following method steps: (a) driving the tool with a motor torque M Mot with a sinusoidal shape with amplitude {circumflex over (M)} Mot and with two defined measurement frequencies f 1 and f 2 ; (b) measuring one of the amplitude {circumflex over (ω)} R of the rotor speed ω R of the motor and the amplitude of the gear unit torque {circumflex over (M)} G ; (c) calculating the inertia Θ S of the tool based on a mathematical model using variables {circumflex over (M)} Mot , {circumflex over (ω)} R , f 1 , f 2 and {circumflex over (M)} G and the previously determined inertia Θ R of the tool drive; and (d) determining the tool diameter from one of a given comparison table and comparison curve of a graph showing the relationship of tool inertia Θ S to tool diameter.