Closed-loop identification of infrared oven in HDD manufacturing process

An infrared oven temperature in hard disk drive (HDD) manufacturing process is controlled by using PID controller. The control temperature problems of old infrared oven due to exceeded temperature and settling time because the physical of old infrared oven is changed. The parameters of PID controller are not appropriate for a new condition. Therefore the infrared oven control system will have low efficiency. In practical cases, the desired performance characteristics of temperature control system are specified in terms of the transient response to step input. This paper proposes a controller design and identification technique for an infrared oven in HDD manufacturing process. An approximated transfer function for an infrared oven investigated from the closed-loop identification by using nonlinear least squares method and the optimization of PID controller design is obtained via gradient descent method. The experimental and simulation results showed good control performance in actual operations.