Researchers dream of developing autonomous humanoid robots which behave/walk like a human being. Biped robots, although complex, have the greatest potential for use in human-centered environments such as the home or office. Studying biped robots is also important for understanding human locomotion and improving control strategies for prosthetic and orthotic limbs. Control systems of humans walking in cluttered environments are complex, however, and may involve multiple local controllers and commands from the cerebellum. Although biped robots have been of interest over the last four decades, no unified stability/balance criterion adopted for stabilization of miscellaneous walking/running modes of biped robots has so far been available. The literature is scattered and it is difficult to construct a unified background for the balance strategies of biped motion. The zero-moment point (ZMP) criterion, however, is a conservative indicator of stabilized motion for a class of biped robots. Therefore, we offer a systematic presentation of multi-level balance controllers for stabilization and balance recovery of ZMP-based humanoid robots.
Inhaltsverzeichnis (Table of Contents)
- Abstract
- 1. Introduction
- 2. Gait cycle
- 3. Stability
- 3.1 Zero-Moment Point (ZMP)
- 3.2 Centroidal angular momentum
- 3.3 Footstep-based criteria
- 4. ZMP-based control
- 5. High-level control
- 5.1 Online reference walking patterns
- 5.2 Balance control
- 6. Low-level control
- 7. Conclusions
- References
Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)
This paper aims to provide a systematic overview of multi-level balance controllers for stabilizing and recovering balance in ZMP-based humanoid biped robots. It addresses the challenges of biped robot stability, particularly the lack of a unified stability criterion across various walking and running modes. The paper focuses on ZMP as a conservative indicator of stabilized motion and explores various control strategies.
- Gait cycle analysis of biped locomotion
- Stability criteria for biped robots (ZMP, centroidal angular momentum, footstep-based criteria)
- Multi-level control systems for biped robots based on the ZMP criterion
- Challenges in biped robot design and control (instability, nonlinearity, high DOFs, environmental interaction)
- Comparison and analysis of different balance control strategies
Zusammenfassung der Kapitel (Chapter Summaries)
1. Introduction: This chapter introduces the field of mobile robotics, focusing on legged robots and their advantages over wheeled and tracked robots, particularly biped robots. It highlights the potential applications of biped robots in human-centered environments and emphasizes their importance in understanding human locomotion. The chapter also outlines the challenges associated with biped robot design and control, such as instability, nonlinearity, high degrees of freedom, and interaction with unknown environments. It positions the paper within the existing literature, highlighting its contribution as a systematic presentation of multi-level balance controllers.
2. Gait cycle: This section describes the gait cycle of biped locomotion, focusing on the double-support phase (DSP) and the single-support phase (SSP). It explains the complexities of biped mechanisms and how researchers often simplify the gait cycle for analysis and control. The chapter emphasizes the importance of understanding these phases for the development of effective control strategies.
3. Stability: This chapter delves into the stability criteria for biped robots, distinguishing between static and dynamic stability. It introduces the concept of the support polygon and explains how static stability restricts gait speed. The chapter focuses on three key dynamic stability techniques: Zero-Moment Point (ZMP), centroidal angular momentum, and footstep-based criteria. Each technique is discussed in relation to its application in biped locomotion and its limitations.
3.1 Zero-Moment Point (ZMP): This sub-section provides a detailed explanation of the Zero-Moment Point (ZMP), its significance in biped robot stability, and the methods for calculating its location. It compares two formulations for ZMP calculation: a more computationally intensive approach based on inertial and gravitational forces and a less computationally intensive approach using ankle joint torques and ground reaction forces. The characteristics of ZMP-based biped mechanisms are discussed, along with limitations and challenges.
3.2 Centroidal angular momentum: This sub-section explores the use of centroidal angular momentum as a stability criterion for biped robots. It describes how the angular momentum can be used as an index for rotational posture control and introduces the concept of the zero rate of change of angular momentum (ZRAM) point and the centroidal moment pivot (CMP). The chapter discusses control strategies for manipulating angular momentum to maintain balance.
Schlüsselwörter (Keywords)
Biped robot, Stability, Zero-moment point (ZMP), Balance, Multi-level control, Gait cycle, Centroidal angular momentum, Dynamic stability, Humanoid robot, Control systems
Frequently Asked Questions: Multi-Level Balance Controllers for Stabilizing Humanoid Biped Robots
What is the main topic of this paper?
This paper provides a comprehensive overview of multi-level balance controllers designed to stabilize and recover balance in ZMP-based humanoid biped robots. It addresses the challenges of biped robot stability, focusing on the Zero-Moment Point (ZMP) as a key stability indicator.
What are the key objectives of this research?
The primary objective is to present a systematic overview of multi-level balance control systems for biped robots. The research explores various stability criteria, including ZMP, centroidal angular momentum, and footstep-based methods, and analyzes different control strategies to achieve stable locomotion.
What are the key themes discussed in the paper?
Key themes include gait cycle analysis, various stability criteria (ZMP, centroidal angular momentum, footstep-based criteria), multi-level control system design, challenges in biped robot control (instability, nonlinearity, high degrees of freedom), and a comparative analysis of different balance control strategies.
What is the Zero-Moment Point (ZMP), and why is it important?
The Zero-Moment Point (ZMP) is a crucial concept in biped robot stability. It represents the point on the ground where the net moment of all inertial and gravitational forces acting on the robot is zero. Maintaining the ZMP within the support polygon is essential for stable bipedal locomotion.
How many levels of control are discussed in the paper?
The paper focuses on multi-level control systems, distinguishing between high-level control (responsible for online reference walking patterns and balance control) and low-level control (details not explicitly elaborated in the preview).
What are the different stability criteria discussed?
The paper examines three main stability criteria: the Zero-Moment Point (ZMP), centroidal angular momentum, and footstep-based criteria. Each criterion offers a different perspective on biped stability and has its own advantages and limitations.
What are the challenges in biped robot design and control?
Biped robot control presents significant challenges due to inherent instability, nonlinear dynamics, high degrees of freedom, and the need to interact with unpredictable environments.
What is the structure of the paper?
The paper is structured with an introduction, a section on gait cycle analysis, a detailed section on stability criteria, a section on ZMP-based control, a section on high-level and low-level control, conclusions, and a list of references.
What are the key chapters and their summaries?
The provided preview includes summaries for the Introduction (setting the context and highlighting the challenges of biped locomotion), the Gait Cycle (describing the double and single support phases), and Stability (detailing the ZMP, centroidal angular momentum, and footstep-based criteria for stability).
What are the keywords associated with this research?
Key words include biped robot, stability, Zero-moment point (ZMP), balance, multi-level control, gait cycle, centroidal angular momentum, dynamic stability, humanoid robot, and control systems.
- Quote paper
- Hayder Al-Shuka (Author), 2017, An Overview on Balancing and Stabilization Control of Biped Robots, Munich, GRIN Verlag, https://www.hausarbeiten.de/document/375226
