Weighing a moving object using captured torque data

An in-line weighing apparatus comprising:

• an intake transport belt assembly arranged for moving a mail piece along a predetermined transport path at a predetermined intake transport speed;
• a weighing station positioned along the transport path to receive a mail piece from the intake transport assembly while the mail piece is moving at substantially the transport speed;
• the weighing station arranged for gripping a mail piece after the mail piece is released from the transport belt assembly;
• the weighing station including
• a capstan servo motor arranged to rotate in synchrony with the moving mail piece;
• a capstan servo controller coupled to the capstan servo motor to drive the capstan servo motor to a predetermined, constant command speed that is different from the transport speed;
• the capstan servo controller also arranged to acquire motor torque data from the capstan servo motor as the mail piece moves through the weighing station, so that the captured torque data reflects the torque applied by the servo motor to change the mail piece speed from the intake transport speed to the command speed;
• and
• a processor arranged to determine a weight of a mail piece from the captured torque data.

An in-line weighing apparatus comprising:

• a primary transport belt assembly arranged for moving a mail piece along a predetermined transport path at a predetermined transport speed;
• the primary transport belt assembly including a pair of transport belts for gripping a mail piece between them, the pair of transport belts arranged to insert the mail piece into a weighing station and also routed around the weighing station and arranged to receive a mail piece when it exits the weighing station;
• a weighing station positioned along the transport path and located to receive a mail piece from the primary transport belt assembly for weighing the mail piece while the mail piece is moving along the transport path, by changing the speed of the mail piece;
• the weighing station including a pair of weigh belts arranged for gripping a mail piece between them for weighing;
• and the weighing station including means for capturing data that describes an impulse applied to a motor to change the speed of the mail piece while the mail piece is gripped by the weigh belts;
• a pair of secondary transport belts arranged for gripping a mail piece there-between as it exits the weighing station and moving the mail piece along the transport path at the predetermined transport speed;
• wherein the primary transport belts, and the secondary transport belts, are arranged so that none of them contacts the mail piece while the mail piece is gripped in the weighing station during a weighing operation.