A Real-Time Unity Framework for Integrated High- and Low-Level Drone Control: Standoff Object-Tracking Strategy as a Use Case

Developing multirotor control systems can require separate tools for vehicle dynamics, low-level control, high-level autonomy, visualization, and data collection. This paper presents a modular framework implemented natively in Unity to support experiments examining interactions across these layers within one standalone environment. Implemented in C#, the framework combines an individual-rotor multirotor model, a quaternion-based cascaded low-level controller, a parametric trajectory generator, runtime parameter controls, and telemetry/data export. A position-based visual servoing extension implements standoff object tracking. The framework is evaluated through step-response and trajectory-following experiments, comparisons of dead-zone and fixed-radius tracking, and execution profiling. In the tested tracking scenarios, the fixed-radius approach maintained spatial constraints more strictly during smooth target motion, whereas the dead-zone approach reduced unnecessary corrections and generally improved screen-space stability, particularly around abrupt direction changes. Screen-space evaluation used target positions supplied by Unity ground truth; image-based detection was not assessed. Real-time stress tests on the tested laptop showed that the standalone builds maintained an approximately 1:1 real-time factor across the tested 0.5–10 kHz range; their frame rates reached the 30 FPS usability threshold at approximately 9 kHz for IL2CPP and 8.5 kHz for Mono. The results demonstrate the feasibility of using Unity for integrated multilevel-control prototyping and experimentation. An interactive WebGL demonstration with runtime parameter adjustment and telemetry is publicly available online.