基于高阶多项式的爬游机器人足端轨迹规划

Research on robot foot trajectory planning based on high-order polynomials

摘要:

针对深海爬游机器人足端轨迹规划问题,采用高阶多项式拟合的方法对其进行研究。首先,介绍了爬游机器人整体结构并对其进行运动学建模,结合爬游机器人运动学模型提出了一种直线与曲线相结合的机器人足端轨迹。其次,利用四阶多项式和六阶多项式分别对机器人足端轨迹进行拟合,比较两种拟合结果可知,六阶多项式拟合方法对机器人足端速度、加速度的规划效果更佳。利用六阶多项式轨迹拟合方法对多段轨迹连接点处的速度问题进行了分析,解决了机器人在运动过程中腿部抖动问题,使机械腿具有良好的控制柔顺性。最后,根据D-H法则建立机器人单腿仿真模型,通过仿真验证了算法的可行性,进一步在水池中利用机器人实物样机验证了算法的有效性。

Abstract:

For the foot trajectory planning problem of underwater crawling-swimming robots, this paper proposes a multi-segment foot trajectory and investigates the high-order polynomial fitting methods. Firstly, the overall structure of the crawling-swimming robot is introduced and the kinematic model is consequently presented. Considering the crawling motion characteristics and the kinematic model, a multi-segment foot trajectory is proposed by integrating two straight lines and a curve. Next, both the fourth-order polynomial method and the sixth-order polynomial method are used to fit the foot trajectory. Comparing the two fitting results, it can be seen that the sixth-order polynomial fitting method has a better planning effect on the robot foot-end velocity and acceleration. the sixth-order polynomial trajectory fitting method is used to calculate the joint points of the multi-segment trajectory. The speed problem is analyzed, and the problem of the leg shaking during the movement of the robot is solved, so that the mechanical leg has good control flexibility. Finally, the single-leg simulation model of the robot is established based on the DH law, and the feasibility of the algorithm is verified by simulation. The effectiveness of the foot trajectory proposed in this paper has been verified by an actual prototype of the underwater crawling-swimming robot.