Development of a Stable Bipedal Robot Locomotion System with Multi-sensory Feedback

• Main Authors: Chen-Yun Kuo, 郭振耘
• Other Authors: Chung-Hsien Kuo
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/67m2x9

碩士 === 國立臺灣科技大學 === 電機工程系 === 104 === Controlling an adult-size humanoid robot is a challenging and difficult task due to mechanical rigidity, backlash, ground environment and other unknown factors which may cause the robot to fall. Therefore, this thesis proposed a gait stability control system for humanoid robots based on multi-sensory feedback, in order to deal with the uncertainty. The system is consist of two pressure sensing units and a 9-axis inertial measurement unit (IMU). The pressure sensing unit is used to measure center of pressure (COP) of the foot during the robot is walking. The area as well as the center of the area (COA) formed by the COP trajectory in a stride is then calculate. In the other hand, the gyroscope in the IMU is used to measure the angular velocity along the roll axial, which is then calculated as half cycle-base gyro stable index (HCBGSI). In order to adapt to different environment, such as slopes, uneven ground, etc., the position of each joints will be adjust based on the information from pressure sensing units and the IMU to let the robot reach the initial conditions before the robot performing a stride. The initial condition is defined as follows: the left and the right ankles of the robot are parallel to the ground, the COP locate in origin of the robot coordinate and the hip plane of the robot is horizontal. After the robot began to walk, the adjustment is divided into two parts: a cycle-base adjustment and a real-time adjustment. In the cycle-base adjustment, COA and CBGSI will be used to calculate the adjustment of the bias and amplitude of hip swinging. In addition, all corrections in the cycle-base adjustment would be performed in next stride. As for the real-time adjustment, the correction is made based on the angular velocity along the roll axial measured from the gyroscope. Since it is a real-time adjustment, the correction is then output to the hip plane immediately to increase the stability. Finally, the adult size platform HuroEvoutionAD is used in this study. After the experiment, the robot was able to perform fast walking with 25cm per footstep and stable walking on a 15% slope. Compared to the original system, the ability of robot walking on slope was enhanced twice times, and the walking speed become 40% faster after implementing the proposed system.