Experimental Modeling of Pneumatic Muscle Actuator

The soft pneumatic actuator is regarded as safer and more natural in the soft robotic field. Numerous new models based on McKibben's muscles have lately been developed. Currently, one of the most important requirements is that the performance of these actuators must be more accurately modeled. This paper proposed a mathematical model that experimentally assessed the mechanical behavior and performance of two types of McKibben’s muscle: Contractor and Extensor muscle actuators, which are popularly used in soft robotic design due to their ease of implementation, low weight to high power, and controllable compliance. This mathematical model research experimentally tests and compares the characteristics of two types of soft actuators to demonstrate their strong and weak points. These two types of pneumatic muscles can be used in constructing a soft robot end effector. The proposed mathematical model is investigated experimentally and constructed depending on the mechanical behavior of the pneumatic muscle. The spring element represents the change in muscle length with the generative force and the applied pressure effect, and the damper element represents the hysteresis characteristics due to friction in PMA components. The study concluded the performance of pneumatic muscle actuators (PMAs) to mathematically model the behavior of both contractor and extensor PMAs.