Accurate real-time estimation of end effector interaction forces in hydraulic excavators is a key enabler for advanced automation in heavy machinery. Accurate knowledge of these forces allows improved, precise grading and digging maneuvers. To address these challenges, we introduce a high-accuracy, retrofittable 2D force- and payload estimation algorithm that does not impose additional requirements on the operator regarding trajectory, acceleration or the use of the slew joint. The approach is designed for retrofittability, requires minimal calibration and no prior knowledge of machine-specific dynamic characteristics. Specifically, we propose a method for identifying a dynamic model, necessary to estimate both end effector interaction forces and bucket payload during normal operation. Our optimization-based payload estimation achieves a full-scale payload accuracy of 1%. On a standard 25 t excavator, the online force measurement from pressure and inertial measurements achieves a direction accuracy of 13 degree and a magnitude accuracy of 383 N. The method's accuracy and generalization capability are validated on two excavator platforms of different type and weight classes. We benchmark our payload estimation against a classical quasistatic method and a commercially available system. Our system outperforms both in accuracy and precision.

翻译：液压挖掘机末端执行器交互力的精确实时估计是重型机械实现高级自动化的关键使能技术。准确掌握这些力可改进并实现精确的平地与挖掘操作。针对这些挑战，本文提出一种高精度、可加装的二维力与载荷估计算法，该算法对操作者的轨迹规划、加速度控制或回转关节使用均无额外要求。该方法专为可加装性设计，仅需最小化标定且无需预先掌握机器特定的动态特性。具体而言，我们提出一种动态模型辨识方法，该模型对于正常作业中末端执行器交互力与铲斗载荷的同步估计至关重要。基于优化的载荷估计实现了1%的全量程载荷精度。在标准25吨挖掘机上，通过压力与惯性测量的在线力测量实现了13度的方向精度与383 N的幅值精度。该方法的精度与泛化能力在两种不同类型及重量等级的挖掘机平台上得到验证。我们将载荷估计性能与经典准静态方法及商用系统进行对比，本系统在精度与准确度方面均优于两者。