Related Experiment Videos
Modeling the dynamic characteristics of pneumatic muscle
D B Reynolds1, D W Repperger, C A Phillips
1Department of Biomedical, Industrial and Human Factors Engineering, Wright State University, Dayton, OH 45435, USA. david.reynolds@wright.edu
Annals of Biomedical Engineering
|April 12, 2003
Summary
A new three-element model accurately describes pneumatic muscle dynamics. This model, comprising contractile, spring, and damping elements, precisely predicts muscle behavior under varying pressures.
Area of Science:
- Robotics and Control Systems
- Biomechanical Engineering
- Fluid Power Systems
Background:
- Pneumatic muscles (PMs) are increasingly used in robotics and prosthetics.
- Accurate dynamic modeling of PMs is crucial for precise control.
- Existing models may not fully capture the complex dynamics of PMs.
Purpose of the Study:
- To develop and validate a novel three-element phenomenological model for pneumatic muscle dynamics.
- To investigate the pressure-dependent characteristics of PMs.
- To assess the model's accuracy in predicting both static and dynamic responses.
Main Methods:
- A pneumatic muscle system was subjected to controlled actuation pressure using a linear servo-valve.
- PM length changes were measured with a linear potentiometer.
- A static perturbation method determined spring and damping element functions, while step and triangular pressure inputs were used to determine the contractile element and validate the model.
Main Results:
- The study established a parallel three-element model (contractile, spring, damping) for PMs.
- Model coefficients were found to be dependent on actuation pressure (207-621 kPa).
- The model accurately predicted dynamic responses to step and triangular pressure inputs, and damping coefficients differed during contraction and relaxation.
Conclusions:
- The proposed three-element model effectively captures the dynamic behavior of pneumatic muscles.
- Static perturbation results are applicable to dynamic responses, simplifying model development.
- The model provides a foundation for improved control strategies in pneumatic muscle applications.