# Principles and Methods of Servomotor Control: Comparative Analysis and Applications
## 5 Comparison of Servomotor Control Methods  
Comparison of servomotor control methods may vary to some extent for each technical solution; therefore, this work proposes a general comparison based on several parameters: speed, accuracy, adaptability, energy efficiency, popularity, ease of implementation, and material resource costs. These are general indicators that can be used to assess the effectiveness of the presented control methods and choose the most suitable one for a specific case.  
Each characteristic plays a key role in building a control system and is evaluated on a five-point scale:  
* Speed is necessary to evaluate the responsiveness of the control system to incoming disturbances and changes in input parameters (1--low speed, 5--high speed).  
* Accuracy is the primary parameter for systems based on positioning (1--low accuracy, 5--high accuracy).
* Adaptability is responsible for the degree of adaptability of the control system to changing conditions (1--low flexibility, 5--high flexibility).
* Energy efficiency indicates the amount and quality of consumed energy (1--increased energy consumption, 5--low energy consumption).
* Popularity not only indicates the degree of method dissemination in the industry but also access to reliable information on creating a control system based on a particular method (1--low popularity, 5--high popularity).
* Ease of implementation is important for assessing the complexity of developing and maintaining the created control system (1--easily implemented, 5--difficult to implement).
* Material resource costs influence the economic factor of developing a control system, its costliness, and payback period, considering efficiency and performance aspects (1--high costs, 5--low costs).  
A visual comparison of characteristics is provided in Figure 5.  
As seen from the comparison, the most popular and energy-efficient method today is the programmable control of servomotors. However, the simplest to implement is PWM control, and in terms of adaptive control, fuzzy logic algorithm is considered. In terms of accuracy, three control methods stand out: two-loop control, FOC, and fuzzy logic control. In summary, when choosing a method for servomotor control, it is advisable to consider the initial characteristics of the desired control, i.e., to select control parameters that bear greater responsibility for performing specific operations.  
In the control of the Hirata Cartesian robot's servomotor operations, direct control based on fuzzy logic algorithm is used. This is because the algorithm is not only used for motor control but also for diagnosing mechanical damage in the robot's transmissions. Therefore, important characteristics for servomotor control include accuracy, adaptability, and control speed. Additionally, the adaptability of fuzzy logic, coupled with high precision, allows its utilization in configuring digital twins for modeling various conditions and behavioral variations. Fuzzy logic facilitates the development of a control system along multiple directions, enabling the digital twin to emulate human logic based on external  
Figure 5: Comparison of the main characteristics of servomotor control methods.  
factors. This human-like decision-making ability is crucial in scenarios where rigid rule-based systems may fall short, providing a more nuanced and realistic approach.