Control Engineering LAB

Model Error Compensator

"Model Error Compensator" is a method for adding robustness to existing control systems. A structure of "model error compensator" was proposed by us, and it has been applied to various control systems. The control objective of the model error compensator (MEC) is to minimize as much as possible the effect of the model error and the disturbance in the meaning of the input-output relation. This compensator has a simple form and is easy to apply to various types of existing control systems, such as non-linear systems, control systems with time delay, non-minimum phase systems, MIMO systems, and so on. Various types of control schemes, such as the model predictive control, can be used together with the model error compensator and can achieve good robust performance. 

Most recent paper about MEC: H. Okajima, Model Error Compensator for adding Robustness toward Existing Control, Preprints of the IFAC World Congress, pp. 3998 - 4005 (2023) (PDF link,science direct)

JP(日本語ページ)

Structure of Model Error Compensator
MEC for Nonlinear Systems
Compensated System with Model Errror Compensator

MEC

Model Error Compensator to Overcome Disturbances and Modeling Error

Very simple structure

High gain feedback

Inverse system is NOT required in MEC structure (Merit compared to "disturbance observer". 

Basic idea is firstly proposed in 2013 PDFLINK ( JCMSI PAPER )

MATLAB code ( github )  and related papers paper1 paper2 

MATLAB code for MEC Hiroshi-Okajima (github.com) 

MATLAB m-files for MEC

[16] Ryuichiro Yoshida, Hiroshi Okajima and Takumi Sato, Model error compensator design for continuous- and discrete-time non-minimum phase systems with polytopic-type uncertainties, SICE Journal of Control, Measurement, and System Integration, Volume 15 Issue 2 pags 141-153 (2022) (T&F, Open Access) 

[15] R. Yoshida, Y. Tanigawa, H. Okajima, and N. Matsunaga, A Design Method of Model Error Compensator for Systems with Polytopic-type Uncertainty and Disturbances, SICE Journal of Control, Measurement, and System Integration, Volume 14 Issue 2 pags 119-127 (2021) (T&F, Open Access)

[14] H. Okajima, Y. Nakabayashi and N. Matsunaga, Signal-Limitation Filters to Simultaneously Satisfy Constraints of Velocity and Acceleration Signals, JCMSI, Volume 13 Issue 1 Pages 1-8 (2020) (T&F, Open Access)

[12] G. Ichimasa, H. Okajima, K. Okumura and N. Matsunaga：Model Error Compensator with Parallel Feed-Forward Filter, SICE Journal of Control, Measurement, and System Integration, Vol.10, No.5, pp.468-475 (2017)  (T&F, Open Access)

[7] A. T. Zengin, Y. Maruno, H. Okajima, N. Matsunaga：Maneuverability Improvement of Front-Drive-Type Electric Wheelchair STAVi, SICE Journal of Control, Measurement, and System Integration, Vol.6, No.6, pp.419-426 (2013)  (T&F, Open Access)

[6] H. Okajima, H. Umei, N. Matsunaga and T. Asai：A Design Method of Compensator to Minimize Model Error, SICE Journal of Control, Measurement, and System Integration, Vol.6, No.4, pp.267-275 (2013)  (T&F, Open Access)

[2] H. Okajima, N. Matsunaga and S. Kawaji：Design of Dynamic Quantizers for 2-DOF IMC and Its Application to the Temperature Control of a Heat Plate, SICE Journal of Control Measurement and System Integration, Vol.4, No.1, pp.77-82 (2011)  (T&F, Open Access)

International conference paper

[65] H. Okajima, Model Error Compensator for adding Robustness toward Existing Control, Preprints of the IFAC World Congress, pp. 3998 - 4005 (2023)

[61]R. Yoshida, Y. Tanigawa, H. Okajima and N. Matsunaga: A Design Method of Model Error Compensator using Meta-Heuristics and LMIs, Proceedings of the SICE Annual Conference 2020 pp. 1150-1155 (2020)

[53] Nobutomo Matsunaga, Naufal Bayu Fauzan, Hiroshi Okajima and Gou Koutaki, Archive Method of Stone Wall in Kumamoto Castle Lifted by Small CMG Crane using Model Error Compensator, 2019 12th Asian Control Conference , 18849231 (2019)

[50] Yuta Nakabayashi, Hiroshi Okajima, Nobutomo Matsunaga, Inter-Vehicle Distance Stabilization in Adaptive Cruise Control Using Signal Limitation Filter, Proceeding of 2018 IEEE International Conference on Systems, Man, and Cybernetics, pp.1985-1990 (2018)

[44] S. Sakamoto, T. Tanaka, H. Okajima and N. Matsunaga：Maneuverability evaluation of skid steer welfare vehicle for robust assistance control with model error compensator, Proceedings of ICCAS 2017 (2017)

[43] N. Matsunaga, H. Okajima and Y. Yamamoto：Robust variable stiffness control of McKibben type pneumatic artificial muscle arm by using multiple model error compensators, Proceedings of ICCAS 2017 (2017) 

[40] Y. Nakabayashi, H. Okajima and N. Matsunaga：Signal limitation filter to satisfy velocity and acceleration constraints for arbitrary input signals, Proceedings of the SICE Annual Conference 2017

[38] T. Tanaka, H. Okajima and N. Matsunaga：Experiment of robust driving assistance control for skid steer welfare vehicle using model error compensator, Proceedings of ICCAS 2016 (2016) Outstanding Paper Award

[36] G. Ichimasa, K. Okumura, H. Okajima and N. Matsunaga：Extended structure of MEC for thermal process, Proceedings of the SICE Annual Conference 2016, pp.1593-1598 (2016)

[32] T.Sugano, H.Okajima and N.Matsunaga：Robust and precise platoon driving control of welfare vehicles along wheel track by using model error compensator, IECON2015, YF-001503

[28] T. Sugano, Y. Dan, H. Okajima, N. Matsunaga and Z. Hu：Indoor Platoon Driving of Electric Wheelchair with Model Error Compensator along Wheel Track of Preceding Vehicle, The 5th International Symposium on Advanced Control of Industrial Processes, 2014.5

[27] Y. Dan, H. Okajima, N. Matsunaga, Z. Hu and N. Nakamura：Experiment of Indoor Platoon Driving using Electric Wheelchair STAVi Controlled by Modeling Error Compensation System, ICT-PAMM Workshop on Mobility Assistance and Service Robotics, p26-31, 2013.11.

[25] Y. Maruno, Y. Dan, A. T. Zengin, H. Okajima and N. Matsunaga：Maneuverability Analysis of Front Drive Type Personal Vehicle STAVi using Modeling Error Compensation System, 7th IFAC Symposium on Advanced in Automative Control, 2013.9.

[18] H. Umei, H. Okajima, N. Matsunaga and T. Asai：A design method of compensator to minimize model error, SICE Annual Conference 2011, 2011.9.