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Analysis and control of a running spring-mass model with a trunk based on virtual pendulum concept.
O K Karagoz1,2, G Secer3,4, M M Ankarali1,2
1Electrical and Electronics Engineering Department, Middle East Technical University, Ankara, Turkey.
Bioinspiration & Biomimetics
|May 6, 2022
Summary
The virtual pivot point (VPP) concept improves legged robot control by analyzing trunk dynamics during running. A new controller enhances stability and robustness for complex robotic locomotion.
Area of Science:
- Robotics
- Biomechanics
- Control Theory
Background:
- The spring-loaded inverted pendulum model is limited for complex robot locomotion.
- It fails to capture trunk dynamics like pitch oscillations.
- The virtual pivot point (VPP) concept addresses these limitations, inspired by biological locomotion.
Purpose of the Study:
- To comprehensively analyze the VPP concept for planar running behaviors.
- To systematically study the existence and characteristics of periodic solutions in VPP models.
- To develop and evaluate a feedback controller for stabilizing VPP dynamics.
Main Methods:
- Analysis of VPP concept for planar running.
- Systematic study of periodic solutions and their dependence on control parameters.
- Development and evaluation of a novel feedback controller for VPP systems.
- Comparison of controller performance based on stability and energetic cost.
Main Results:
- Periodic solutions were identified and analyzed concerning model parameters.
- A new feedback controller was developed, demonstrating effectiveness.
- The proposed controller offers larger basins of attraction with minimal impact on convergence speed compared to existing methods.
- Both controllers proved effective in stabilizing system dynamics.
Conclusions:
- The VPP concept, coupled with the proposed controller, is valuable for designing and controlling legged robots with significant upper body dynamics.
- This study provides a foundation for comparing the VPP concept with biological locomotion.
- Further research can build upon the systematic analysis of periodic solutions for advanced robotic locomotion.
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