Method and equipment for measuring mass inertia of moving surfaces

Abstract

A method for measuring mass inertia of moving surfaces, comprising the steps of: (a) Alignment of the center of gravity of an assembly ( 90 ) formed by the moving surface ( 50 ) and a support device ( 70 ) fastened to at least two joints ( 31, 32 ) in a rest position, this alignment comprising a reading in a comparing clock ( 40 ) and driving of an adjusting element arranged in the support device ( 70 ) for obtainment of a predetermined value in the comparing clock ( 40 ); (b) Measurement of the static moment of assembly (M static ) in an intermediate position through a dynamometer ( 60 ); (c) Measurement of the oscillation period of assembly (T) in a pendulum position through an accelerometer arranged in the support device ( 70 ) and (d) Reading of the static moment of assembly (Mstatic) and that of oscillation period of assembly (T) and obtainment of the inertial moment of the moving surface (I hhsup )—An equipment ( 10 ) for measurement of mass inertia of moving surfaces, is further described, comprising: a structure ( 20 ) formed by first and second structural bodies ( 21, 22 ) concurrently, thus forming a free gap ( 23 ) for positioning of moving surfaces ( 50 ); the first structural body ( 21 ) comprising at least two joints ( 31, 32 ) fastened to its upper portion ( 211 ) and a comparing clock ( 40 ) arranged in its lower position ( 212 ); the structural body ( 22 ) comprising a dynamometer ( 60 ) positioned in an extension ( 25 ); and a support device ( 70 ) associated with at least two joints ( 31, 32 ) and in collaboration with a comparing clock ( 40 ) and the dynamometer ( 60 ).

1 . Method for measuring inertial mass of moving surfaces, characterized for comprising the steps of:
 (a) Alignment of the gravity center of an assembly ( 90 ) formed by the moving surface ( 50 ) and a support device ( 70 ) fastened at least to two joints ( 31 ,  32 ) in a rest position, this alignment comprising a reading in a comparing clock ( 40 ) and driving of an adjusting element arranged in the support device ( 70 ) for obtainment of a predetermined value in the comparing clock ( 40 );   (b) Measurement of the static moment of assembly (M static ) in an intermediate position through a dynamometer ( 60 );   (c) Measurement of the oscillation period of assembly (T) in a pendulum position through an accelerometer arranged in the support device ( 70 ) and (d) Reading of the static moment of assembly (M static ) and that of the oscillation period of assembly (T) and obtainment of the inertial moment of the moving surface (I hhSup ).   
     
     
         2 . Method, according to  claim 1 , characterized in that, prior to step (a), the inertial moment of support device (I hhDisp ) is obtained separately. 
     
     
         3 . Method, according to  claim 2 , characterized in that, the inertial moment of support device (I hhDisp ) is stored in a dada acquisition and processing system ( 200 ). 
     
     
         4 . Method, according to  claim 1 , characterized in that, in step (b), the intermediate position of assembly consists in rotation of assembly ( 90 ) regarding at least two joints ( 31 ,  32 ) at 90° angle from the rest position. 
     
     
         5 . Method, according to  claim 1 , characterized in that, at step (b) a free end ( 73 ) of the support device ( 70 ) is supported in the dynamometer ( 60 ) and the reading of the static moment of assembly (M static ) is performed in the dynamometer ( 60 ). static, is 
     
     
         6 . Method, according to  claim 5 , characterized in that, the static moment datum of assembly (M static ) is collected and stored by a data acquisition ands processing system ( 200 ). 
     
     
         7 . Method, according to  claim 1 , characterized in that, at step (c), assembly ( 90 ) is taken to the rest position, and then rotated in the range of 1° to 5° regarding the rest position and released, thus allowing a free oscillation. 
     
     
         8 . Method, according to  claim 7 , characterized in that, through the free oscillation of assembly ( 90 ), the oscillation period of assembly (T) is measured by accelerometer and sent to a data acquisition and processing system ( 200 ). 
     
     
         9 . Method, according to  claim 1 , characterized in that, step (d) is carried out by a data acquisition and processing system ( 200 ). 
     
     
         10 . Method, according to  claim 9 , characterized in that, the inertial moment of a moving surface (I hhSup ) is obtained from equation (II)
     I   hhSup   =I   hhSup+Disp   −I   hhDisp    (II)
   
     
     
         11 . Equipment ( 10 ) for measuring mass inertia of moving surfaces, characterized for comprising:
 a structure ( 20 ) formed by first and second structural bodies ( 21 ,  22 ) concurrently, thus forming a free gap ( 23 ) of positioning of moving surfaces ( 50 );   the first structural body ( 21 ) comprising at least two joints ( 31 ,  32 ) fastened to its upper portion ( 211 ) and a comparing clock ( 40 ) arranged at its lower portion ( 212 );   the second structural body ( 22 ) comprising a dynamometer ( 60 ) positioned in an extension ( 25 ); and   a support device ( 70 ) associated with at least two joints ( 31 ,  32 ) and in collaboration with the comparing clock ( 40 ) and the dynamometer ( 60 ).   
     
     
         12 . Equipment, according to  claim 11 , characterized in that the support device ( 70 ) comprises a main bar ( 71 ) perpendicularly associated with a secondary bar ( 72 ), thus forming a “T”, the main bar ( 71 ) being fastened to at least two joints ( 31 ,  32 ) and a secondary bar ( 72 ) in collaboration with the comparing clock ( 40 ) and the dynamometer ( 60 ) through a free end ( 73 ). 
     
     
         13 . Equipment, according to  claim 12 , characterized in that the free end ( 73 ) of the secondary bar ( 72 ) comprises an accelerometer. 
     
     
         14 . Equipment, according to  claim 13 , characterized in that the moving surface ( 50 ) is associated to the support device ( 70 ), thus forming an assembly ( 90 ). 
     
     
         15 . Equipment, according to  claim 14 , characterized in that the size of the support device ( 70 ) varies in light of the size of the moving surface ( 50 ) to be associated. 
     
     
         16 . Equipment, according to  claim 14 , characterized for comprising an adjusting device ( 41 ) in collaboration with the support device ( 70 ), thus aligning and adjusting the assembly ( 90 ) with at least two joints ( 31 ,  32 ). 
     
     
         17 . Equipment, according to  claim 11 , characterized in that the extension ( 25 ) is positioned substantially perpendicular to the second structural body ( 22 ) and comprises a movement ruler ( 61 ) to which the dynamometer ( 60 ) is fastened, this movement ruler ( 61 ) being displaced as per the movement of the support device ( 70 ). 
     
     
         18 . Equipment, according to  claim 11 , characterized for comprising a data acquisition and processing system ( 200 ) positioned adjacent to the structure ( 20 ).