Design of the joint of an advanced adaptive Tendon-Actuated robot manipulator

Project Overview

Institution: Sun Yat-sen University, ShenZhen, CN
Advisor: Prof. Deshan Meng
Duration: March 2023 - August 2023
Research Type: Undergraduate Thesis Project

This undergraduate research project investigated the design and implementation of a novel joint mechanism for tendon-driven robotic systems. The focus was on developing a lightweight joint design that could achieve improved torque output through lever arm amplification principles.

Research Background and Problem Statement

Tendon-driven robotic systems offer advantages in terms of lightweight design and remote actuation capabilities. However, achieving high torque output while maintaining system compactness remains a challenge. This research explored a potential solution through the design of a lever arm amplification joint mechanism.

The project aimed to address the following key challenges:

• Designing a compact joint mechanism that can effectively amplify output torque
• Maintaining lightweight characteristics while ensuring structural stability
• Developing a practical prototype for experimental validation

Figure 1: Overall design of the advanced adaptive tendon-actuated robot manipulator joint showing the innovative lever arm amplification mechanism optimized for space applications.

Technical Approach: Lever Arm Amplification Joint

The core focus of this undergraduate thesis was the development of a lever arm amplification joint mechanism. The design aimed to enhance torque output capabilities in tendon-driven systems through mechanical advantage principles, while maintaining a compact and lightweight structure.

Figure 2: Illustration of the joint mechanism's operation, showing the configuration before and after actuation. The red lines indicate the tendon routing path and demonstrate how the lever arm mechanism influences force transmission.

Research Methodology

The project followed a systematic approach combining theoretical analysis with practical implementation:

• Initial concept development and mechanical design of the lever arm mechanism
• Kinematic analysis to understand joint behavior and force transmission
• Prototype fabrication using appropriate materials and manufacturing techniques
• Experimental testing to validate the mechanism's performance

Prototype Development

A functional prototype was developed to validate the lever arm amplification concept. The prototype allowed for testing of the joint mechanism under various conditions and provided valuable insights for design optimization. Key aspects of the prototype development included:

• Component design and selection for the joint mechanism
• Assembly and integration of the mechanical systems
• Implementation of the tendon routing system
• Testing setup for performance evaluation

Figure 3: Demonstration of the prototype's range of motion, showing the joint mechanism in various configurations from fully extended to different bending angles. The physical prototype (bottom) validates the design concept illustrated in the schematic diagrams (top).

Research Results

The research successfully developed and tested a prototype of the lever arm amplification joint mechanism. The experimental results demonstrated the feasibility of the design concept for improving torque output in tendon-driven systems while maintaining lightweight characteristics.

Applications

While the research was conducted with space robotics applications in mind, the developed joint mechanism could potentially be adapted for various robotic applications where high torque output and lightweight design are important considerations.

Future Research Directions

This undergraduate thesis project laid groundwork for potential future research in tendon-driven robotic systems. Future work could explore:

• Advanced control algorithms for precise joint angle control
• Integration of multiple joints into a complete robotic arm system
• Further optimization of the lever arm mechanism for specific application requirements
• Experimental validation under various loading conditions

Conclusion

This undergraduate thesis project successfully explored the design and implementation of a lever arm amplification joint mechanism for tendon-driven robotic systems. The work combined theoretical analysis with practical prototyping, providing valuable hands-on experience in mechanical design and robotics research.

System Optimization and Future Research Directions

Through comprehensive system optimization of space-domain driven robotic arms, this research successfully achieved intelligent adjustment for cable-driven robotic arm systems. The optimization process focused on enhancing overall system performance while maintaining the core advantages of lightweight design and high torque output capabilities.

The success of this undergraduate thesis opens several avenues for future exploration. Advanced control algorithms, multi-joint systems, and integration with autonomous navigation could further enhance the capabilities of tendon-driven space robotics. Future research could explore adaptive control strategies that dynamically adjust lever arm configurations based on task requirements.

The principles developed in this research could also be applied to terrestrial robotics where high force-to-weight ratios are crucial, such as search and rescue operations, medical robotics, and industrial automation in weight-sensitive applications. The mathematical modeling framework and 3D manufacturing techniques developed could be extended to create more complex multi-degree-of-freedom systems.