The research focuses on the R-Han 122, a 122-millimeter surface-to-surface artillery rocket developed as part of Indonesia’s indigenous defense-technology program. According to the article, the existing R-Han 122 configuration operates as an unguided rocket, meaning its trajectory is strongly influenced by initial launch conditions and aerodynamic disturbances. The researchers examined whether a harmonic-control approach could help address the control challenges associated with a continuously rolling airframe.
Why Rolling Motion Creates a Control Challenge
Rolling can contribute to aerodynamic stability, but it also creates a complicated interaction between the rocket’s movements. As the airframe continuously rotates, the relationship between the control surfaces and the surrounding airflow changes. This can produce dynamic coupling between the pitch and yaw axes and make control less effective.
The researchers explain that harmonic control works by synchronizing control inputs with the rolling motion. Instead of treating the rotation as something that must be eliminated, the control system adapts its input to the changing orientation of the airframe.
The approach was evaluated through an integrated MATLAB and X-Plane 10 environment. The simulation used a six-degree-of-freedom flight model to represent the rocket’s movement in multiple dimensions.
Computer Simulation Replaced Early-Stage Flight Testing
Rather than immediately testing the control system on physical hardware, Lubis, Yogaswara, and Nugroho used numerical simulation to examine how different control settings affected flight behavior.
The simulation showed that introducing roll without compensation increased oscillatory behavior. After harmonic control was applied, the control input became synchronized with the rocket’s rolling motion, reducing the oscillatory response and maintaining control effectiveness.
Moderate Control Amplitude Produced the Best Balance
The researchers tested harmonic-control amplitudes of 0, 0.1, 0.5, and 1.0 at frequencies of 0.3, 0.5, and 0.8 Hz. Flight performance was assessed through variables including pitch movement and maximum altitude.
One of the clearest findings was that an amplitude of 0.5 consistently produced the lowest pitch peak-to-peak response across the tested frequencies.
This indicates that effective control requires an appropriate balance. Control that is too weak may not sufficiently compensate for disturbances, while excessive control can introduce additional oscillations.
Telemetry Shows Stable Simulated Flight
The researchers analyzed simulated telemetry covering altitude, ground trajectory, roll, pitch, yaw, forward velocity, forward acceleration, and harmonic-control input.
Across the tested scenarios, the simulated rocket maintained controllable flight trajectories. Pitch showed the most noticeable changes and was therefore used as an important indicator of longitudinal flight stability.
The study found that the moderate amplitude of 0.5 consistently reduced pitch oscillations while maintaining stable altitude, velocity, and ground-trajectory profiles. Increasing the amplitude beyond that level produced larger oscillatory responses, although the simulations did not show divergent flight behavior or complete loss of control.
The authors conclude that harmonic control can reduce the adverse effects of roll-induced dynamic coupling while maintaining stable simulated altitude, trajectory, velocity, and overall flight behavior. The findings also confirm that control performance depends strongly on selecting suitable amplitude and frequency parameters.
Potential Contribution to Indigenous Defense Technology
For Indonesia’s defense-technology development, the significance of the study lies primarily in its simulation framework. The integrated MATLAB–X-Plane environment allows researchers to examine control strategies and tune parameters before moving toward hardware development or flight testing.
The authors state that the work provides practical insights into harmonic-controller implementation and parameter optimization for indigenous missile technology. However, the study remains a simulation-based investigation and does not demonstrate performance under real-world flight conditions.
The researchers identify several factors that were not included in the simulations, including aerodynamic uncertainties, environmental disturbances, actuator dynamics, and sensor noise. They recommend further validation through hardware-in-the-loop simulations or experimental flight testing.
For the wider defense-research community, the result illustrates how digital simulation can be used to evaluate complex flight-control concepts before costly physical testing. It also highlights the importance of parameter optimization rather than simply increasing control intensity.
Author Profile
Farhan Syafiq Rizqullooh Lubis: Department of Weapon Technology, Faculty of Defense Technology and Engineering, Indonesia Defense University. He is the corresponding author of the article and can be contacted through the email address listed in the publication.
Y.H. Yogaswara: Department of Weapon Technology, Faculty of Defense Technology and Engineering, Indonesia Defense University.
Larasmoyo Nugroho: Department of Weapon Technology, Faculty of Defense Technology and Engineering, Indonesia Defense University.
Research Source
Article title: “Design and Simulation of Harmonic Control for a Rolling Airframe R-Han 122 Surface-to-Surface Missile Using MATLAB–X-Plane Integration”
Authors: Farhan Syafiq Rizqullooh Lubis, Y.H. Yogaswara, and Larasmoyo Nugroho
Journal: International Journal of Advance Social Sciences and Education (IJASSE)
Publication: Volume 4, Number 4, 2026, pages 365–376
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