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arXiv 2408.03131cs.ROcs.SYeess.SY

基于次优演示的机器人技能获取随机轨迹优化

Stochastic Trajectory Optimization for Robotic Skill Acquisition From a Suboptimal Demonstration

Shanghai Jiao Tong University(上海交通大学);Technical University of Munich (TUM)(慕尼黑工业大学)

Chenlin Ming, Zitong Wang, Boxuan Zhang, Zhanxiang Cao, Xiaoming Duan, Jianping He

AI总结:

针对次优演示轨迹的形状偏好与动态缺陷问题,提出结合DTW和性能指标的成本函数,开发鲁棒的MSTOMP算法,通过频域去噪和MSES指标优化,提升机器人技能获取的轨迹性能与稳定性。

摘要:

从演示中学习(LfD)已成为机器人获取新技能的关键方法。然而,当给定具有反映人类偏好的形状特征但动态属性欠佳(如运动缓慢)的次优任务轨迹演示时,机器人不仅需要模仿行为,还需优化动态性能。本研究利用基于优化的方法搜索性能更优且形状与演示轨迹相似的轨迹。具体而言,我们使用动态时间规整(DTW)量化两条轨迹的差异,并将其与碰撞成本等额外性能指标结合构建成本函数。此外,我们开发了运动规划随机轨迹优化(STOMP)的多策略版本MSTOMP,其对参数变化更稳定鲁棒。为处理演示轨迹中的抖动,我们进一步在频域使用增益控制方法对演示去噪,并提出计算效率更高的频谱均方误差(MSES)指标,用于在频域测量轨迹差异。我们还从理论上强调了时域与频域方法的联系。最后,我们在仿真与真实世界实验中验证了该方法,展示其相比现有方法在优化性能和稳定性上的提升。

英文摘要:

Learning from Demonstration (LfD) has emerged as a crucial method for robots to acquire new skills. However, when given suboptimal task trajectory demonstrations with shape characteristics reflecting human preferences but subpar dynamic attributes such as slow motion, robots not only need to mimic the behaviors but also optimize the dynamic performance. In this work, we leverage optimization-based methods to search for a superior-performing trajectory whose shape is similar to that of the demonstrated trajectory. Specifically, we use Dynamic Time Warping (DTW) to quantify the difference between two trajectories and combine it with additional performance metrics, such as collision cost, to construct the cost function. Moreover, we develop a multi-policy version of the Stochastic Trajectory Optimization for Motion Planning (STOMP), called MSTOMP, which is more stable and robust to parameter changes. To deal with the jitter in the demonstrated trajectory, we further utilize the gain-controlling method in the frequency domain to denoise the demonstration and propose a computationally more efficient metric, called Mean Square Error in the Spectrum (MSES), that measures the trajectories' differences in the frequency domain. We also theoretically highlight the connections between the time domain and the frequency domain methods. Finally, we verify our method in both simulation experiments and real-world experiments, showcasing its improved optimization performance and stability compared to existing methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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