Reflow Temperature Control System Research And Development

The developing of SMT(Surface Mount Technology) and electronic component miniaturization has made reflow soldering system application widely. In the process of controlling the system, because the process parameters are nonlinear and non-fixed, the traditional PID controller was difficult to acquire the satisfying control result.The paper accomplished the sirocco-circumfluance reflow soldering system control by the advanced PID algorithm in slave machine. To solve the problem of inefficient manual parameters tuning of the multi-chamber oven, the methods of PID parameters self-tuning was studied. On base of the slave machine methods, the interpolation fuzzy-PID parameters online self-tuning algorithm in master machine was put forward. The main work was listed as follows:1. To meet the need of its trait and its practical production, the multi-CPU embedded hardware design and the relevant software design was finished. Furthermore, the novel anti-jamming measure was adopted by combining of the hardware and software which were both restricted.2. An simplified PID self-tuning method using golden section single parameter optimization was put forward, and according to the exist of detected disturb in spot, feedforward and alterable integral PID feedback compound control algorithm which was applied in the temperature object is studied.3. Aimed at some defects of control algorithm in slave machine, the fuzzy-PID parameter online self-tuning algorithm based on master machine is developed. Because the fuzzy controller can't subdivide the E, EC too densely, and the reflow soldering system must response to the disturb in time. To solve this contradiction, a simplified interpolation fuzzy-PID parameters online self-tuning algorithm is put forward and the MATLAB simulation examples are given at the same time.4. Monitor program in master machine with friendly human-computer interface and perfect function is programmed by virtual instrument language?LabWindows/CVI.Now, the slave machine controller has replaced the PLC monitor system totally and puts into the practice for a test. The steady temperature precision can be up to ?...