Mitigating Aging Effects in Fault-Tolerant FPGA-Based Controllers for Flexible Manufacturing

This paper focuses on the issue of FPGA-based controller reliability in the context of Flexible Manufacturing Systems (FMS). Due to the industrial harsh environment, FPGA-based controllers are susceptible to both failures and aging effects. A framework that integrates Fault-Tolerant (FT) FPGAs with aging mitigation capabilities is proposed to improve FPGA-based industrial controllers' reliability and extend their lifetime. The fault set includes soft faults represented by both Single Event Upsets (SEUs) and Multiple Event Upsets (MEUs), hard faults, and aging effects. The design relies on a customized Triple Modular Redundancy (TMR) technique for fault detection and masking with Dynamic Function eXchange (DFX) capability for partial reconfiguration. In most cases, the reconfiguration does not require any system interruption. The design is also able to differentiate between hard, soft and aging failures. Finally, a simple case study is described to illustrate the system's behavior upon infection by hard fault or aging. The Zybo Z7-20 board is used in this case study.