External contact force is one of the most significant information for the robots to model, control, and safely interact with external objects. For continuum robots, it is possible to estimate the contact force based on the measurements of robot configurations, which addresses the difficulty of implementing the force sensor feedback on the robot body with strict dimension constraints. In this paper, we use local curvatures measured from fiber Bragg grating sensors (FBGS) to estimate the magnitude and location of single or multiple external contact forces. A simplified mechanics model is derived from Cosserat rod theory to compute continuum robot curvatures. Least-square optimization is utilized to estimate the forces by minimizing errors between computed curvatures and measured curvatures. The results show that the proposed method is able to accurately estimate the contact force magnitude (error: 5.25\% -- 12.87\%) and locations (error: 1.02\% -- 2.19\%). The calculation speed of the proposed method is validated in MATLAB. The results indicate that our approach is 29.0 -- 101.6 times faster than the conventional methods. These results indicate that the proposed method is accurate and efficient for contact force estimations.
翻译:外部接触力是机器人模型、 控制和安全地与外部天体互动的最重要信息之一。 对于连续机器人,可以根据对机器人配置的测量来估计接触力,这解决了在严格的尺寸限制下对机器人身体执行力感应反馈的困难。在本文中,我们使用从纤维布拉格仪(FBGS)测量到的本地曲线来估计单个或多个外部接触力的大小和位置。一个简化机械模型来自Cosserat 棒理论,以计算连续机器人曲线。最差的优化用于通过尽量减少计算曲线和测量曲线之间的误差来估计力量。结果显示,拟议的方法能够准确估计接触力强度(eror: 5.25- 12.87 ⁇ )和位置(eror: 1.02-- 2.19 ⁇ )。 拟议的方法的计算速度在MATLAB中得到验证。结果显示,我们的方法是29.0 -- 101.6比常规方法快10.6倍。这些结果显示,拟议的方法对接触力估计是准确和高效的。