Dynamic Modeling and Error Mechanism Analysis of a Laboratory Drilling Fluid Automatic Batching System

Abstract

To address the issues of low accuracy in adding trace amounts of powder and the susceptibility of dynamic weighing to disturbances during the preparation of laboratory drilling fluids, this paper conducts an in-depth dynamic modeling and error mechanism analysis of an automatic batching system. First, by analyzing the physical characteristics of the screw feeding mechanism and the resistance strain-gauge load cell, a full-link dynamic mathematical model was constructed, encompassing material flow rate, a second-order weighing system, and the material falling impact force. Next, using a conventional dual-speed feeding strategy as the subject, numerical simulations were performed with Python to quantitatively investigate the effect of the speed switching magnitude (∆n) during the coarse/fine feeding stages on the system's dynamic response. The simulation results indicate that the falling impact force is the primary cause of the weighing system's transient oscillations, and its oscillation amplitude exhibits an approximately linear positive correlation with the speed switching magnitude ∆n. The study reveals that to meet the high-precision batching requirement of ±0.01 g, the speed switching magnitude must be strictly constrained. The research outcomes of this paper provide a solid theoretical foundation and key parameter design guidance for the subsequent development of high-precision, high-stability flexible control strategies.