3D-SLIP model based dynamic stability strategy for legged robots with impact disturbance rejection

Area of Science:

• Robotics
• Biomechanics
• Control Systems

Background:

• The 2D spring-loaded inverted pendulum model effectively describes running but struggles with 3D lateral disturbances.
• Increased degrees of freedom in 3D locomotion lead to higher computational complexity and control challenges for legged robots.

Purpose of the Study:

• To develop a robust control strategy for legged locomotion that can effectively reject lateral impact disturbances.
• To enhance the stability and adaptability of legged robots in dynamic, three-dimensional environments.

Main Methods:

• A novel 3D-HFC control strategy was developed, building upon the classical Raibert controller.
• The strategy integrates touchdown angle control, body attitude angle control, and energy compensation modules.
• Real-time energy loss measurement and prediction were incorporated to manage step-to-step dynamics.

Main Results:

• The 3D-HFC strategy demonstrated efficiency in simulations using a 3D-SLIP model and a quadruped robot under various impact forces.
• Experimental validation on a quadruped bionic prototype (MBBOT) confirmed the strategy's effectiveness in rejecting lateral impact disturbances.
• Both simulation and real-world experiments showed successful disturbance rejection capabilities.

Conclusions:

• The proposed 3D-HFC control strategy enables legged robots to maintain stability and reject lateral impact disturbances in 3D locomotion.
• This approach enhances the robustness of legged robots, making them more adaptable to complex and unpredictable environments.