Dispensing system and method of controlling the same

摘要

A method of controlling a dispensing system (14) to dispense a viscous material (10) onto a workpiece (12) at an actual dispensing rate within a minimum deviation of a target dispensing rate is provided. The method includes dispensing the viscous material (10) onto the workpiece (12) during first (T1) and second (T2) time periods and measuring a pressure of the viscous material (10) after each of a plurality of time increments (ti) within the time periods (T1,T2). A theoretical volume of the viscous material (10) dispensed during each of the time periods (T1,T2) is determined based on the pressure measurements (P). An actual volume of the viscous material (10) dispensed during the first (T1) and second (T2) time periods is also measured. The theoretical and actual volumes are then compared to determine first (f1) and second (f2) new values for a compensation factor (f). The first (T1) and second (T2) time periods are consecutive such that the first new value (f1) for the compensation factor (f) compensates the actual dispensing rate in the second time period (T2) for changes in operational characteristics of the viscous material (10) and the dispensing system (14) that occurred in the first time period (T1).