This study presents the design and implementation of a real-time flight-path tracking control system for a quadrotor unmanned aerial vehicle (UAV) capable of accurately following a mobile ground target under dynamic and uncertain environmental conditions. The proposed framework integrates classical fixed-gain PID regulation executed on Pixhawk with its built-in adaptive mechanisms, namely autotuning, hover-throttle learning, and dynamic harmonic notch filtering, to enhance robustness under communication latency and disturbances. No machine learning PID tuning is used on Pixhawk; adaptive features are estimator based rather than ML based. The proposed system addresses critical challenges in trajectory tracking, including real-time delay compensation between the UAV and rover, external perturbations, and the requirement to maintain stable six-degree-of-freedom (DOF) control of altitude, yaw, pitch, and roll. A dynamic mathematical model, formulated using ordinary differential equations with embedded delay elements, is developed to emulate real-world flight behavior and validate control performance. Experimental evaluation demonstrates robust path-tracking accuracy, attitude stability, and responsiveness across diverse terrains and weather conditions, achieving a mean positional error below one meter and effective resilience against an 8.2 ms communication delay. Overall, this work establishes a scalable, computationally efficient, and high-precision control framework for UAV guidance and cooperative ground-target tracking, with potential applications in autonomous navigation, search-and-rescue operations, infrastructure inspection, and intelligent surveillance. The term “delay-aware” in this work refers to the explicit modeling of the measured 8.2 ms end-to-end delay and the use of Pixhawk’s estimator-based adaptive mechanisms, without any machine learning-based PID tuning.

The sit-to-stand (STS) model from a biomechanical point of view is an enormously important subject, with motor controls simulating human intended behavior. Physiological motion-based biomechanical research is important for designing whole-body prosthetics and understanding physical disabilities. The control strategies for biomechanical models can effectively synergize with the central nervous system (CNS) to facilitate the desired movements of individuals with neurological disabilities. In this study, we present our novel 3D biped model by decoupling it into healthy and neurologically deficient joints. The developed 8-segment model (i.e., 2× feet, 2× shanks, 2× thighs, 1× pelvic, and 1× Head Arm Torso (HAT) segment) with 10 joints is decoupled into 6 healthy joints and 4 deficient joints. This decoupling mimics stroke patients or subjects with neuromuscular deficiency. This novel decoupling establishes through asymmetrical torques in frontal and sagittal plane joints on a bipedal design with one foot fixed and the other a sliding tilt joint. In this design, two decoupled controllers collaborate to stabilize the nonlinear model for biped STS transfer. Utilizing the xml files from SOLIDWORKS, the model is linearized in SIMSCAPE / SIMULINK. We further imply the Linear Quadratic Regulator (LQR) optimal controller design in MATLAB / SIMULINK for torques in both the sagittal and frontal planes, respectively, for six healthy and four deficient joints. We also comprehend the forward thrust velocity controls to pragmatically model the STS of stroke patients. This decoupling enhanced the overall stability of the system and simulated more relevant angular and velocity profiles for neurologically deficient substances.

The construction of a rigid body biomechanical model with higher ordered controller design is a challenging task due to the complicated architecture and complexity of human intended movements. Biomechanical analysis of such complex model for sit-to-stand (STS) movement in three dimensions (3D) requires the envisioned actions of humans by utilizing motor controls. The current study aims to enhance our investigation into 3D bipedal mobility by creating optimal control for our novel Twist and Tilt foot mechanism. Unlike earlier models, this mechanism does not assume any fixed foot for the entire profile. This novel model type enables one foot to perform a twisting motion and the other foot to execute a sliding tilt motion. This technique simulates the control effort needed during the STS task by individuals with neurological impairments while performing various joint positions. The twist and tilt model is created using computer-aided design (CAD) software SOLIDWORKS, utilizing an 8-segment biped. The linearized model in SIMULINK generated 24th ordered State Space model. Subsequently, we developed LQR (linear quadratic regulator) controller for attaining the desired trajectories in MATLAB/SIMULINK. This novel twist and tilt optimal control strategy have improved angular profiles and simulation results showcase the stroke patient’s movements with one foot sliding deficient tilt and other foot twisting during the profile.

The field of biomechanics for human voluntary motions in three dimensions encompasses a wide array of applications. The process of transitioning from a seated position to a standing position, referred to as sit-to-stand, is a basic motion that is frequently executed during various everyday tasks. The current investigation centers on enhancing 3D bipedal locomotion through the creation of a novel system utilizing a Twist and Tilt scheme to perform sit-to-stand (STS) movements. This mechanism, in contrast with previous models, does not consider any foot fixed for the whole profile. This type enables one foot to perform a twisting movement and the other foot to perform a tilting movement. The tilt foot schematic is built with two distinct schemes: one involving sliding tilt, the other with rotating tilt. This scheme is designed to study STS issues faced by neurologically deficient human beings while carrying out different joint positions. The twist and tilt models are designed using computer-aided design (CAD) software. They consist of an 8-part bipedal structure, which includes two feet, two calves / shanks, two thighs, one pelvis, and one HAT section. Both of these twist and tilt models are first produced in SOLIDWORKS Corp software. Subsequently, to facilitate control implementation, these models undergo linearization using SIMULINK / SIMSCAPE and MATLAB. By employing the analysis of Controllability and Observability, it is revealed that the design, which incorporates one foot linear tilt, consists of twelve states. Furthermore, it is determined that one foot linear model has full rank controllability and observability and is suitable to design controller.