Theoretical Modeling, Analysis, and Experimental Results of a Hydraulic Artificial Muscle Prototype

Fluidic braided artificial muscles have been studied for close to seventy years. Their high power-to-weight ratio and force-to-weight ratio make them a desirable actuation technology for compact and lightweight mobile manipulation. Use of hydraulics with fluidic artificial muscles has helped realize high actuation forces with new potential applications. To achieve large actuation forces produced from high internal pressure, artificial muscles operate near the limitations of their mechanical strength. Design improvements and future applications in mechanical systems will benefit from detailed theoretical analysis of the fluidic artificial muscle mechanics. This paper presents the theoretical modeling of a hydraulic artificial muscle, analysis of its mechanics, and experimental results that validate the model. A prototype is analyzed that operates at 14 MPa and can generate up to 6.3 kN of force and a displacement of 21.5 mm. This model promises to be useful for mechanical system design and model-based control.