tailieunhanh - InTech-Climbing and walking robots towards new applications Part 4

Tham khảo tài liệu 'intech-climbing and walking robots towards new applications part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 90 Climbing Walking Robots Towards New Applications called the gravity-compensated inverted pendulum method generates a leg trajectory with higher stability while keeping the most of the simplicity of the inverted pendulum mode intact . Park 1998 . A more complicated method to generate a more stable trajectory is based on the Zero Moment Point ZMP equation which describes the relationship between the joint motions and the forces applied at the ground Yamaguchi et al 1996 . The ZMP is simply the center of pressure at the feet or foot on the ground and the moment applied by the ground about the point is zero as its name indicates. Yamaguchi et al. 1996 and Li et al. 1992 used trunk swing motions and trunk yaw motions respectively to increase the locomotion stability for arbitrary robot locomotion. However many previous researches have assumed a predetermined ZMP trajectory. Due to the difference between the actual environment and the ideal one or a modeling error and the impact of foot-ground biped robots are likely to be unstable by directly using the original planned gait. In order to maintain the stability of bipedal walking the pre-planned gait needs to be adjusted. When the robot is passing through obstacles or climbing up stairs the adjustment of the preplanned gait may lead to the collision between the biped robot and the environment. Then the trajectory should be wholly re-planned and the pre-planned gait becomes useless. This is the problem that conventional gait plan method encountered. In the view of to separate the space and time the gait of a bipedal walking can be decomposed into two parts the geometric space path of the robot passing through which reflect the relative movement between all moving parts of the robot then the specific moments of the robot pass through the specific points of the geometric space path which contain the velocities and accelerations information and is connected to the reference of time. According to this view we proposed a