Study On Bionic Design Of High-speed Leg Mechanism And Its Trajectory Generation Method

Cheetah has the highest speed in mammals in the nature.And as bionic target,cheetah has always been a research hotspot of quadruped robots.Biological studies have found that the power mainly is provided by its hind legs when it runs.The ability of cheetah's high-speed running is closely related to its leg bone structure,muscle distribution and foot trajectory.Therefore,the cheetah's leg structure as the bionic object and a mechanical leg with high-speed movement ability is designed in this paper.A parameterized algorithm for generating the foot trajectory is proposed to imitate cheetah's when it runs,and it is tested successfully on the mechanical leg.The main finished tasks are as follows:To analysis the characteristics of cheetah's foot-trajectory,the bezier curve was used to generate the foot trajectory,the reasonable objective function and constraint conditions were established.And the particle swarm optimization algorithm was used to optimize the control parameters of the trajectory to form a parameterized generation algorithm of the foot trajectory.The algorithm can generate a shape which is fitting the foot trajectory curve of a cheetah by determining a few parameters.After investigating the characteristics of cheetah's leg,such as bone structure and muscle distribution,the structure and the size of the mechanical leg were determined.Combined with cheetah's muscle distribution characteristics,move the motor to the torso to reduce the inertia of the leg,and the 3d model and the prototype of the mechanical leg were designed.The control system for the mechanical leg is built,and the FreeRTOS real-time operating system is used as the control core in the lower computer to improve the real-time response.The upper computer interface program and the communication program between those two computers are written.Finally,the bionic foot trajectory method based on Bessel curve is tested on the high-speed leg mechanism experiment platform.It has proved that the mechanical leg mechanism can follow the target trajectory,and the bionic foot trajectory can effectively realize the movement of the mechanical leg by the suspension and ground running test,...