The Research And Implementation Of A Temperature Controller With PID Auto-Tuning

As an important temperature control device, the PID temperature controller has been widely used in many industrial processes. However, the PID parameters of the general PID temperature controller must be set manually by professional engineers, according to their experiences. It is inconvenient for the customers who need to change PID parameters frequently, which restricts the application of the temperature controller. Aiming at this situation, this dissertation makes a study of the temperature controller with PID auto-tuning for the need of temperature control in mid-scale and small-scale corporation, designs and develops a kind of temperature controller.First, the dissertation introduces the PID auto-tuning development and the embedded system. Two PID auto-tuning methods based on relay feedback and step identification are analyzed theoretically and are simulated by Matlab. After contrastive analysis, the method with the best combination property is applied in the temperature controller. According to the modular design philosophy, this dissertation proposes the complete block design project. The temperature controller can auto-tune the PID parameters, controls multi-channel temperature, monitors dc and ac voltage, communicates with other controllers by Modbus protocol. And then this dissertation analyses and discusses the design and implementation of the primary modules. At present, the temperature controller has been developed successfully, and a good effect has been achieved. It can be used for temperature control in mid-scale and small-scale corporation.