Dynamic Gait Generation for a Leg-Wheel Transformable Robot Based on Force Control

• Main Authors: Yun-Meng Lin, 林筠萌
• Other Authors: 林沛群
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/25mme6

碩士 === 國立臺灣大學 === 機械工程學研究所 === 106 === Multi-legged robots are one of the most popular topics in robotics owing to their ability to move stably and their superior obstacle negotiation. In recent years, most research teams have put their emphasis on force control strategies because they allow the robot to tolerate greater error compared to position control, and therefore make the motion more robust. The purpose of this thesis is to develop dynamic gaits for a leg-wheel transformable robot, TurboQuad, and evaluate its motion performance. Model-based control is used and the SLIP (spring-loaded inverted pendulum) model is chosen. A force control method is developed to make the translational degree of freedom of the leg-wheel perform spring-like motion to match the spring in the SLIP model. Parameters of the SLIP model that suit the robot are searched for, to initiate dynamic gaits such as trotting and pronking. Then the effects of these parameters are discussed to build the basis for choosing suitable trajectories. The ability to transition between two stable operation points is also developed. Besides, hopping behavior is accomplished by current control. The original control structure of TurboQuad is preserved (i.e. Central Pattern Generator) and combined with model-based control. The mechatronic system is upgraded to meet the requirements for the robot to perform versatile behaviors. A turning strategy is developed and differential steering is used to reduce slippage. The performance of the robot in terms of energy efficiency, obstacle negotiation ability and motion smoothness are also evaluated.