A method (200) for pre-balancing a crankshaft, the method (200) comprising the steps (202, 204, 222) of receiving data related to a three dimensional scan of the crankshaft; generating a model based on the data; and providing instructions, based on the model, for defining a pre-balancing machining axis.

Method for obtaining the inertial properties of a movable (10) rotating around a hinge line (2) in an aircraft control surface (1), comprising the following steps:

a) removing the actuators mechanical connections from the movable (10), leaving it free to rotate around its hinge line (2), further balancing the movable (10) and calculating in a first approach its coarse static momentum;

b) refining the static momentum of the movable (10) obtained in a), and obtaining simultaneously its frictional momentum;

c) incorporating an elastic element (300) on the control surface (1), configuring a second order mechanical system;

d) inducing forced oscillations on the movable (10) at a certain frequency, this frequency being increased until it is sensibly close to the resonance frequency of the movable (10);

e) calculating, from the wave response in d), the momentum of inertia of the movable (10).

A rigid body characteristic identification system which identifies rigid body characteristics of a measurement target including its mass and center of gravity position, provided with an immovable stationary part 10, moving parts 20 which can move with respect to the stationary part and include a measurement target T, support means 30 for supporting the moving parts with respect to the stationary part in a freely vibratable manner, measuring means 40 for measuring data which is necessary for calculating the natural frequency of the moving parts when the moving parts are vibrating, and analyzing means 50 for receiving as input the support conditions by the supporting means and the measurement data which was measured by the measuring means and for performing processing based on these support conditions and natural frequency calculated from the measurement data. The analyzing means uses the support conditions by the supporting means and natural frequencies which are calculated from the measurement data as the basis to identify the rigid body characteristics of the measurement target. Due to this, a rigid body characteristic identification system or rigid body characteristic identification method which can reduce the number of measurement points while identifying the rigid body characteristics with a high precision is provided.

A center-of-gravity detecting system (100) includes a motion detector (14) for detecting a vertical motion of a travelling object in a self-weight direction during travel and a horizontal motion of the travelling object in a widthwise direction during travel, and an arithmetic unit (15). The arithmetic unit (15) calculates a center-of-gravity location of the travelling object in the self-weight direction in a cross-section perpendicular to the travel direction of the travelling object and a center-of-gravity location of the travelling object in the widthwise direction in the cross-section perpendicular to the travel direction, using the frequency of a vertical motion of the travelling object in the self-weight direction, a frequency of the horizontal motion of the travelling object in the widthwise direction, a central angle of the horizontal motion of the travelling object in the widthwise direction, and the width of the traveling object. The arithmetic unit (15) calculates a center-of-gravity location of the travelling object in the travel direction, using the frequency of the vertical motion of the travelling object in the self-weight direction, a frequency of the horizontal motion of the travelling object in the travel direction, the center-of-gravity location of the travelling object in the self-weight direction, and the length of the travelling object in the travel direction.

Die Erfindung betrifft ein Verfahren zur drehgeberlosen Identifikation mechanischer Kenngrößen eines Drehstrom-Asynchronmotors (09). Das Verfahren umfasst zumindest die Schritte:

- Konstantspannungseinprägung U_1α in α-Achsenrichtung zur Erzeugung eines Konstantmagnetflusses;

- Testsignalspannungseinspeisung U_1β in β-Achsenrichtung des Asynchronmotors (09), wobei die α-Achsenrichtung konstant bestromt bleibt;

- Meßsignalstrommessung I_1β in β-Statorachsenrichtung des Asynchronmotors (09);

- Identifikation von mechanischen Kenngrößen des Asynchronmotors (09) auf Basis der Testsignalspannung U_1β und des Meßsignalstroms I_1β;

wobei der Rotor (11) Auslenkungsbewegungen (75) ausführen kann.

In nebengeordneten Aspekten betrifft die Erfindung eine Identifikationseinrichtung (39) für die Bestimmung von mechanischen Kenngrößen eines Asynchronmotors (09) sowie eine diese umfassende Motorsteuerungsvorrichtung (35), wobei die identifizierten Kenngrößen zur Bestimmung, Optimierung und Überwachung einer Motorsteuerung verwendet werden können. Schließlich schlägt die Erfindung eine Verwendung des Identifikationsverfahrens für die Steuerung elektrischer Antriebe vor.

Eine Messvorrichtung für eine Momentenwaage umfasst eine Grundplatte (2) mit mehreren Fixieröffnungen (4), eine drehbar an der Grundplatte (2) angeordnete Aufnahmeplatte (6) mit mehreren Aufnahmeöffnungen (7) und Fixieröffnungen (8), eine an der Aufnahmeplatte (6) angeordnete Messaufnahme (11) für ein Messobjekt (12, 28), wobei die Messaufnahme (11) in einen Teil der Aufnahmeöffnungen (7) eingreift und mehrere Fixierstifte (9), welche die Messaufnahme (11) in einer Messposition fixieren durch Eingriff in einen Teil der Fixieröffnungen (4, 8) in Grundplatte (2) und Aufnahmeplatte (6).