# Experimental Investigation of Free-Motion Task Implementation on a Serial Metamorphic Manipulator
## 5 Conclusions and Future Work  
This study successfully verified the ability of an SMM prototype to achieve task execution efficiency through structural reconfiguration. The validation of theoretical models, based on data from real-world free-motion tasks and simulated performance metrics, was a critical aspect of this research. Based on the scientific claims stated, the main conclusions of this work are the following:  
* Modeling accuracy: Given the simplified dynamic model employed for this initial evaluation, the focus was on analyzing the system's fundamental behavior under basic task conditions, including low end-effector speed and the absence of external forces or loads. Both theoretical and experimental validation results confirmed the  
Figure 16: Acceleration analysis and joint 2’s current in the CP implementation (ID: 1, task path: 16). Figure 17: Acceleration analysis and joint 2’s current in the RP implementation (ID: 3, task path: 28). adequacy of the proposed dynamic model, providing a reliable baseline for comparing simulation data with experimental findings. The theoretical analysis confirmed the model's accuracy, while the experimental validation highlighted that unmodeled dynamics contributed to deviations in joint torques, though overall trends remained consistent. Additionally, systematic errors arising from the inherent inaccuracies and imperfections of the physical robot prototype were evident but did not alter the general representation of the system's dynamic behavior. These findings underscore the utility of the simplified model as a foundational tool for understanding system dynamics and guiding future refinements in modeling and experimental validation. * Dynamic performance evaluation: Various metrics were analyzed to assess their effectiveness in extracting accurate information about the robot's actual behavior. The results of this study successfully identified robot structures that led to enhanced performance and optimized task execution, consistent with findings in the literature [13; 15; 18]. The results demonstrated the value of performance measures in identifying task segments with optimized performance and areas requiring improvement. Despite using a simplified dynamic model, the framework effectively correlated performance indices with trajectory accuracy, highlighting its utility for evaluating and refining control strategies in reconfigurable robotic systems. The results demonstrated that task-based optimization, which incorporated the robot's dynamic properties, brought performance evaluations closer to real-world conditions. This approach provided a more accurate reflection of how modular reconfigurable robots performed in practice, offering significant improvements in task adaptability and precision. * Controller performance: The implementation of simple PID joint position controllers with fixed gains to execute motion commands on the SMM prototype resulted in reduced positional accuracy, particularly in task segments with lower dynamic performance. While task optimization increased the torque-to-acceleration ratio, it also introduced counterproductive effects that must be addressed to enhance controller efficiency and overall performance. Elevated joint currents and current spikes observed in regions with high torque-to-acceleration ratios indicated significant dynamic load variations. These findings underscore the necessity for advanced trajectory optimization techniques and refined control system architectures to achieve improved dynamic performance and energy efficiency. This work provided insights in the fundamental dynamics and interactions within the SMM during simple task execution scenarios. However, the findings also underscore the need for more advanced control and trajectory implementation tools. Future work should focus on developing and integrating these sophisticated tools, which can build upon the foundational results of this study to further enhance the dynamic performance and operational efficiency of SMMs.