Hot isostatic pressing furnaces

A robust fault-tolerant model predictive control (MPC) scheme for the precise control of temperature in hot isostatic pressing (HIP) furnaces was designed based on a nonlinear state-space representation of the dynamics of the temperature in an HIP furnace. The model was developed and validated using the data collected from open-loop experiments. The MPC-based controller was then implemented and tested on a six-zone HIP furnace at Bodycote IMT, Inc. The robust fault-tolerant MPC was demonstrated to outperform the existing PID-based control system in the following aspects: 1) achievement of a heating rate of at least twice that achieved by the existing PID-based system; and 2) automatic detection of loss of power to a furnace zone and controller reconfiguration to achieve the desired process objectives, which with the current PID system would be impossible and would require operator intervention.