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Testbed are used to tune and assess automotive engines. As more High Dynamic (HD) scenarios need to be simulated, the testbeds require Multi Input Multi Output (MIMO) and robust control systems. A cooperation involving a major testbed manufacturer and two university laboratories was therefore set up. This paper presents the Control-System Design (CSD) methodology developed from system identification to the design and assessment of the MIMO robust controller for a HD testbed coupled with a spark-ignition engine. It is specially highlighted how the entire process has been automated and simplified and how the fractional order based MIMO CRONE CSD has been parameterized to obtain the best performance. Experimental results show that the proposed fractional order based MIMO control system is able to improve robustness and decoupling.

This paper proposes an extension of CRONE control and design for unstable, multiple time-delay multivariable plants with right half-plane (RHP) zeros. The CRONE control approach developed for multivariable square plants is based on third generation scalar CRONE methodology. The aim is to find a decoupling and stabilizing controller for the open-loop transfer matrix. Fractional order transfer functions are used to define all the components of the diagonal open-loop transfer matrix, β 0 i . Optimization gives the best fractional open-loop transfer matrix, β . Finally, frequency-domain system identification is used to find a robust controller K = G −1 β . When the plant is inversed, time-delays and RHP poles or zeros can appear on the denominator of the transfer matrix, G −1 . To achieve a stable controller some time-delays, RHP zeros and unstable poles must be included within the diagonal transfer function of the open-loop transfer matrix. To assess the proposed design, the CRONE control approach is applied to a distillation example.