Optimal trajectory planning based on Hamiltonian function of a spherical mobile robot

Designed for planetary exploration,a spherical mobile robot BHQ-1 was briefly introduced.The mo-tion model of BHQ-1 was established and quasi-velocities were introduced to simplify some dynamic quan-tities.Based on the model,the time- and energy-based optimal trajectory of BHQ-1 was planned withHamiltonian function. The effects of three key coefficients on the shape and direction of the planned tra-jectory were discussed by simulations.Experimental result of the robot ability in avoiding an obstacle waspresented to validate the trajectory planning method.

基于MACSF的移动机械臂振动抑制轨迹规划方法

为满足移动机械臂高精度、低抖动的作业需求,提出一种基于修正非对称组合正弦函数(modified asymmetry combined sine function,简称MACSF)的振动抑制轨迹规划方法。首先,针对传统非对称组合正弦函数(asymmetry combined sine function,简称ACSF)存在加速度突变、启停阶段不稳定等问题,以驱动函数加加速度连续平滑为目标,采用改进型组合正弦函数设计加加速度时间窗口中的加速阶段和减速阶段,以降低移动机械臂的关节力矩波动;其次,通过叠加组合方法求出满足约束条件的通用型驱动函数;最后,基于机器人操作系统(robot operating system,简称ROS)搭建移动机械臂抑振算法验证平台,并使用该平台在样机场景下进行了一系列实验验证。结果表明,MACSF方法能够有效抑制移动机械臂的瞬态振动和残余振动(动态作业过程中振幅优于1 mm),从而验证了该方法的有效性和实用性。

一种非链式非完整球形机器人的反步轨迹跟踪控制器(英文)

Spherical robot has good static and dynamic stability, which provides it with strong viability in hostile environment, but the lack of effective control methods has hindered its application and development. This article deals with the dynamic trajectory tracking problem of the spherical robot BHQ-2 designed for unmanned environment exploration. The dynamic model of the spherical robot is established with a simplified Boltzmann-Hamel equation, based on which a trajectory tracking controller is designed by using the back-stepping method. The convergence of the controller is proved with the Lyapunov stability theory. Numerical simulations show that with the controller the robot can globally and asymptotically track desired trajectories, both linear and circular.

在障碍时变工作空间中机器人无碰撞平滑路径规划的一种算法研究

本文应用在障碍时变工作空间中把固定障碍和时变障碍分解的思想.首先就固定障碍问题,为机器人规划一条无碰撞路径,然后通过规划机器人的速度来达到避开活动障碍的目的.本文接着提出在时间-路径空间中以忽略可动障碍时机器人的运动策略为基准策略,根据障碍约束和机器人速度或加速度约束,用有理二次函数来规划机器人避开可动障碍的运动策略.

双足自平衡移动机器人全覆盖搜索任务轨迹优化

考虑双足自平衡移动机器人执行搜索任务时,仅仅以物体轮廓特征作为路径计算的基础,没有考虑可能对路径造成影响的边缘细节特征,易出现采集图像信息较少的问题,且由于搜索环境复杂,同时需要躲避障碍物,导致搜索路径较长、效率偏低。提出双足自平衡移动机器人全覆盖搜索任务轨迹择优方法。优化机器人视觉图像采集结果,并采用灰度变换函数对图像展开灰度变换,将双边滤波函数应用于Retinex算法中,取代传统算法中的高斯滤波,获得环境图像的反射分量,并通过下述公式加权融合处理R、G、B灰度值,获得双足机器人全覆盖搜索任务时保留了边缘且增强细节的图像,并将其输入至支持向量机,识别环境中的目标与障碍物。根据获取的环境信息建立模拟地图,构建机器人搜索任务的路径,通过蚁群算法获取最优路径。实验结果表明,所提方法能够躲避障碍物到达目标位置,且路径距离短、规划效率高。