New method for liquid-medication filling systems

For the systems used to fill large numbers of containers with liquid medication, a permissible relative error is ±1.0%. Here, a medication filling and estimating system was designed to improve cycle time. The nonlinear least squares (NLS) method was used with the proposed system, and the results succeeded in providing the medication fill ration meeting certain specifications and below the permissible relative error. The proposed method also realizes medication filling accuracy comparable to that achieved by the conventional method, but additionally made it possible to shorten the time needed to compute the weight value by approx 60%. Moreover, since a low-pass filter does not need to be used with the proposed method, the new method is not subject to the influence of a time delay.