Dynamic Weighing System

In the feedingstuff production, all sorts of materials are mixed correctly in proportion to make a production. This process is widely used in the industry, such as architecture material, foodstuff process, chemical production. Therefore, to design and develop an automatic system which can weigh materials dynamicly and dispense the errors automaticly is essential.The weigh of the materials is dynamic weighing. It is more difficult than static weighing. All sorts of materials not only need to be weighed precisely, but also need to be compounded correctly in proportion. So it is necessary to control the flow of the material and to adjust the error.The dynamic quantitative weighing process is studied in this thesis. In order to improve the weighing speed and precision simultaneously, the study of signal process method and control arithmetic is made. The main contents are composed of the following parts:1. The thesis summarizes the survey of dynamic quantitative weighing systems, proposes the key matter of a dynamic quantitative weighing system-precision, and points out that the emphases studied in this paper is a spiral feeding dynamic quantitative weighing system.2. Dynamic weighing system is as a second-order system and set it up model, then has its transform function laplace transform and Z transform, at last the Auto-Regressive-moving-Average(ARMA)model for the second order weighing system is derived. The method of resolving dynamic weighting through parameter identification based on least square method is proposed.3. The least square method used to identify system parameters is described, and then describe that how to use paramerters identify method in the dynamic weighing process. The correlative simulation experiments are carried out, too.4. A further study of the dynamic weighing and batching process is made and an iteration self-learning control method is used to dynamic weighting and batching process control. To resolve the random interferer problem, the control method is improved.5. According to the specifications of dynamic quantitative weighing process control in a spiral feeding ,A dynamic quantitative weighing PC-BASED control system is designed, which includes hardware, realization method of software and flow chart of it.