Proposed Design for Pneumatic Artificial Muscles in Soft Robotics System: An Experimental Study

The artificial pneumatic muscle is considered one of the essential flexible actuators used in soft robotics due to its advantages, which include flexibility, lightweight, efficiency, and high tensile strength compared to weight. However, despite these advantages, there is a nonlinear behavior that appears known as hysteresis, which shows a clear difference between the response when increasing and decreasing pressure, which complicates the control process and affects its accuracy. In this research, an experimental study was conducted to examine the hysteresis phenomenon by measuring the relationship between pressure and muscle length in the two stages of increasing and decreasing pressure. By employing experimental data and adopting the arc tangent function, hysteresis was accurately modelled. After that, the results showed an excellent agreement between the mathematical model and the experimental data by found Statistical evaluation for model, which confirms the effectiveness of the function in embodying this nonlinear performance. This model provides a means to develop the control of artificial pneumatic muscle and can be used with different sizes of air muscles made of the same materials because it is pressure dependent, which contributes to the development of applications based on prosthetic limbs and soft robotics.