Abstract: This paper proposes a novel system design scheme based on digital PID control. The system employs independently developed host computer software and a highly reliable programmable controller, and utilizes variable frequency speed regulation to achieve closed-loop control of the batching system, thereby automating the production of the mixing equipment and improving its stability, maintainability, and production efficiency.
Keywords: cold asphalt recycling; PID controller; frequency converter; programmable logic controller
Abstract: In this article, a system design project based on new-fashioned digital PID controller has been given. The system adopts the independent upper machinery software and PLC with great dependability. And with using frequency conversion, closed loop control and the product automation of mixing equipment have been realized. The stability, maintenance and product efficiency of mixing equipment also have been improved.
Keywords: cold asphalt rehabilitation; PID; transducer; PLC
1. Introduction
Asphalt cold recycling mixing technology is a process that reuses old asphalt pavement materials after crushing and processing, adds new aggregates or fine aggregates according to the structural characteristics of the recycled structural layer, adds a certain amount of admixtures (emulsified asphalt, foamed asphalt, etc.) and appropriate amount of water in proportion, and continuously adds and mixes them under natural ambient temperature to re-form a structural layer with load-bearing capacity [1]. This technology makes full use of the waste materials of old pavement, solving the problem of the space occupation and environmental pollution caused by waste materials. Most of the control systems of domestically produced asphalt cold recycling mixing equipment adopt open-loop control electromagnetic speed-regulating motor batching, which has low batching accuracy and poor real-time performance, serious material waste, and increased production costs. In order to solve the above shortcomings, this paper proposes a new design scheme for an automatic control system of asphalt cold recycling mixing equipment based on digital PID control. This scheme forms a closed-loop control of the batching system, with low hardware investment cost, which meets the actual engineering design needs.
For details, please click: Control System Design of New Asphalt Cold Recycling Mixing Equipment
