Positioning and Trajectory Tracking with Deflection Suppression in Flexible Link Robotic Manipulator Using PID-LQR Controller
Main Article Content
Abstract
This study aims to enhance the dynamic response of a flexible link robot manipulator (FLRM) to achieve faster positioning, improved trajectory tracking, and effective suppression of link deflection. A dynamic model of the FLRM was developed, and a hybrid control strategy integrating a proportional–integral–derivative (PID) controller with a linear quadratic regulator (LQR) was designed and implemented within the closed-loop system architecture. The complete system was modeled and simulated using MATLAB/Simulink. Initial simulations assessed the performance of the PID and LQR controllers independently. The PID controller yielded a rise time of 0.2617 s, peak time of 0.9434 s, settling time of 3.2394 s, and overshoot of 11.9676%. In contrast, the LQR controller demonstrated superior dynamic characteristics, with a rise time of 0.2505 s, peak time of 0.3489 s, settling time of 0.4769 s, and minimal overshoot of 0.0048%. To further enhance system performance and reduce trajectory tracking error, a hybrid PID–LQR controller was developed, incorporating refined PID parameters. Simulation results showed that the hybrid controller achieved a rise time of 0.1444 s, peak time of 0.2706 s, settling time of 0.2637 s, and overshoot of 0.5119%. These outcomes demonstrate that the PID–LQR hybrid controller significantly outperforms the individual PID and LQR approaches by achieving near-zero overshoot, faster response, and reduced stabilization time.

Citation Metrics:
Downloads
Citation Metrics & Similar Scopus Articles
-
Li H. (2027)Magnetic coupling resonance-based energy harvesting and high-frequency switching oscillation suppression in power electronic convertersElectric Power Systems Research, 264
-
Yakhyayev K.K. (2027)SELECTING SIGNIFICANT FACTORS IN FORECASTING AND ZONING OF TERRITORIES IN VIRGINIAN JUNIPER PLANTATIONSIndian Journal of Entomology, 89(1), 237-241
-
Chi J. (2027)Heterogeneous interpenetrating strong-tough structure enabling high-strength Cf/C-Nb joints via cold spray-assisted brazingJournal of Materials Science and Technology, 282, 197-208
Article Details

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
References
Alam, W., Ali, N., Aziz, H. M. W., & Iqbal, J. (2018b). Control of flexible joint robotic manipulator: design and prototyping. 2018 International Conference on Electrical Engineering (ICEE), Lahore, Pakistan, 1-6, https://doi.org/10.1109/ICEE.2018.8566796
Alam, W., Mehmood, A., Ali, K., Javaid, U., Alharbi, S., & Iqbal, J. (2018a). Nonlinear control of a flexible joint robotic manipulator with experimental validation. Strojniški vestnik– Journal of Mechanical Engineering, 64(1), 47-55. https://doi.org/10.5545/sv-jme.2017.4786
Alandoli, E. A., Rashid, M. Z. A., & Sulaiman, M. (2017). A comparison of PID and LQR controllers for position tracking and vibration suppression of flexible link manipulator. Journal of Theoretical and Applied Information Technology, 95(13), 2949-2955. https://www.jatit.org/volumes/Vol95No13/7Vol95No13.pdf
Ekengwu, B. O., Eze, P. C., Asiegbu, C. N., Olisa, S. C., & Udechukwu, C. F. (2022). Satellite dish antenna control for distributed mobile telemedicine nodes. International Journal of Informatics and Communication Technology, 11(3), 206~217. DOI: 10.11591/ijict.v11i3.pp206-217
Ekengwu, B. O., Eze, P. C., Muoghalu, C. N., Asiegbu, C. N., & Achebe, P. N. (2024). Design of robust centralized PID optimized LQR controller for temperature control in single-stage refrigeration system. Indonesian Journal of Electrical Engineering and Informatics, 12(3), 726~738. DOI: 10.52549/ijeei.v12i3.5629
Eze, P. C., Onuora, A. E., Ekengwu, B. O., Muoghalu, C., & Aigbodioh, F. A. (2017). Design of a robust PID controller for improved transient response performance of a linearized engine idle speed model. American Journal of Engineering Research, 6(8), 305-313. https://www.ajer.org/papers/v6(08)/ZK0608305313.pdf
Eze P. C., Ugoh C. A., Inaibo D. S. (2021). Positioning control of DC servomotor-based antenna using PID tuned compensator. Journal of Engineering Sciences, 8(1), E9–E16, doi: 10.21272/jes.2021.8(1).e2
Eze, P. C., Muoghalu, C. N., Uebari, B., & Egbunugha, C. A. (2022). State variable feedback control of data centre temperature. International Journal of Advanced Networking and Applications, 14(1), 5250-5257.
Eze, P. C., Nwadike, S. U., Oyiogu, D. C., & Iroegbu, M. C. (2025). Hybrid PID-LQR Controller for Dynamic Response and Stability Enhancement of Synchronous Generator’s AVR System. Asian Journal of Science, Technology, Engineering, and Art, 3(3), 866-879. https://doi.org/10.58578/ajstea.v3i3.5693
Gupta, S., Singh, A.P., Deb, D., & Ozana, S. (2021). Kalman filter and variants for estimation in 2DOF serial flexible link and joint using fractional order PID controller. Applied Science, 11(15), 6693; https://doi.org/10.3390/app11156693
Mbaocha, C., Eze, P., & Uchegbu, V. (2015). Positioning control of drilling tool device for high speed performance. International Journal of Electrical and Electronics Research, 3(2), 138-145. https://www.researchpublish.com/papers/positioning-control-of-drilling-tool-device-for-high-speed-performance
Okoye, U. P., Eze, P. C., & Dennis, C. O. (2021). Enhancing the performance of AVR system with prefilter aided PID controller. Access International Journal of Research & Development, 1(1), 19-32.
Tuan, H. M., Sanfilippo, F., & Hao, N. V. (2021). Modelling and control of a 2-DOF robot arm with elastic joints for safe human-robot interaction. Frontiers in Robotic and AI, 8, 679304. https://doi.org/10.3389/frobt.2021.679304
Ullah, H., Malik, F.M., Raza, A., Mazhar, N., Khan, R., Saeed, A., & Ahmad, I. (2021). Robust output feedback control of single-link flexible-joint robot manipulator with matched disturbances using high gain observer. Sensors, 21(9), 3252. https://doi.org/10.3390/s21093252
Zhang, F. & Yuan, Z. (2021). The Study of Dynamic modeling and multivariable feedback control for flexible manipulators with friction effect and terminal load. Sensor, 21(4), 1522. https://doi.org/10.3390/s21041522
Zhu, M., Ye, L., & Ma, X. (2020). Estimation-based quadratic iterative learning control for trajectory tracking of robotic manipulator with uncertain parameters in IEEE Access, 8, 43122-43133. doi: 10.1109/ACCESS.2020.2977687


















