Weigh-in-motion scale system and method for linear synchronous motor conveyor
A weigh-in-motion scale system for a linear synchronous motor conveyor and a method for weighing objects on a linear synchronous motor conveyor are described herein. In one embodiment, the weigh-in-motion scale system includes a support structure for supporting the following: a weigh cell, a section of a linear synchronous motor conveyor track, a vehicle for transporting an object, and an object; and a weigh cell on the support structure on which a section of a linear synchronous motor conveyor track rests directly or indirectly. In one embodiment, the method includes transporting a vehicle with an object thereon along a section of a linear synchronous motor conveyor track; and at a weighing station while the vehicle with the object thereon is being transported, weighing the section of a linear synchronous motor conveyor track, vehicle, and object to determine the weight of the object.
1. A method for weighing objects on a linear synchronous motor conveyor, said method comprising:
a. providing a weigh-in-motion system comprising:
i. a support structure for supporting the following: a weigh cell, a section of a linear synchronous motor conveyor track, a vehicle for transporting an object, and an object; and
ii. a weigh cell on said support structure on which a section of a linear synchronous motor conveyor track rests;
b. transporting a vehicle with an object thereon along said section of a linear synchronous motor conveyor track; and
c. at a weighing station while said vehicle with an object thereon is being transported, weighing said section of a linear synchronous motor conveyor track, vehicle, and object to determine the weight of said object;
wherein the support structure is configured to support two sections of linear synchronous motor and one section of said linear synchronous motor conveyor track, and the section of the linear synchronous motor track supported by the support structure spans at least portions of the two sections of linear synchronous motor.
2. The method of claim 1 wherein said steps (b) and (c) is carried out on objects being transported at speeds in a range from greater than or equal to about 0.2 m/s to less than or equal to about 20 m/s.
3. The method of claim 1 wherein there are multiple vehicles, wherein each vehicle has a tare weight, and said method further comprises: (1) assigning an identification designation to each vehicle; and (2) step (c) further comprises identifying which vehicle is carrying an object being weighed and subtracting the identified vehicle's tare weight from the reading on the weigh cell.
4. The method of claim 3 further comprising occasionally transporting said vehicles to said weigh station to check the tare weight of said vehicles.
5. The method of claim 4 where one or more of the vehicles are moved to a designated position other than on the checkweigher if the tare weight of the one or more of the vehicles is identified to be outside of a specified range.
6. The method of claim 1 wherein step (c) comprises weighing multiple objects, wherein each object has a different weight, and one object has a lowest weight and another object has a highest weight, wherein the highest object weight is in a range that is between greater than or equal to about 1.1 up to less than or equal to about 1,500 times the lowest object weight.
7. The method of claim 1 wherein the vehicles have spaced apart wheels wherein the vehicles travel along said track with said wheels contacting said track, and said vehicles have a wheel base with a length between greater than 40 mm and less than or equal to about 300 mm.
8. The method of claim 1 further comprising: providing a calibration vehicle with a known weight; and periodically transporting said calibration vehicle to said weigh station to check the calibration of said weigh cell.