In orthopedic surgery, the bone milling force has attracted attention owing to its significant influence on bone cracks and the breaking of tools. It is necessary to build a milling force model to improve the process of bone milling. This paper proposes a cortical bone milling force model based on the orthogonal cutting distribution method (OCDM), explaining the effect of anisotropic bone materials on milling force. According to the model, the bone milling force could be represented by the equivalent effect of a transient cutting force in a rotating period, and the transient milling force could be calculated by the transient milling force coefficients, cutting thickness, and cutting width. Based on the OCDM, the change in transient cutting force coefficients during slotting can be described by using a quadratic polynomial. Subsequently, the force model is updated for robotic bone milling, considering the low stiffness of the robot arm. Next, an experimental platform for robotic bone milling is built to simulate the milling process in clinical operation, and the machining signal is employed to calculate the milling force. Finally, according to the experimental result, the rationality of the force model is verified by the contrast between the measured and predicted forces. The milling force model can satisfy the accuracy requirement for predicting the milling force in the different processing directions, and it could promote the development of force control in orthopedic surgery.

中文翻译：

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基于正交切削分布方法的皮质骨铣削力模型

在整形外科中，由于骨铣削力对骨裂缝和工具的破坏有显着影响，因此引起了人们的关注。必须建立一个铣削力模型以改善骨骼铣削的过程。本文提出了一种基于正交切削分布方法（OCDM）的皮质骨铣削力模型，解释了各向异性骨材料对铣削力的影响。根据该模型，骨铣削力可以用旋转周期中瞬态切削力的等效效应来表示，瞬态铣削力可以通过瞬态铣削力系数，切削厚度和切削宽度来计算。基于OCDM，可以通过使用二次多项式描述开槽过程中瞬态切削力系数的变化。后来，考虑到机器人手臂的低刚度，将更新力模型以进行机器人骨骼铣削。接下来，建立了用于机器人骨骼铣削的实验平台，以模拟临床操作中的铣削过程，并使用加工信号来计算铣削力。最后，根据实验结果，通过实测力与预测力的对比验证了力模型的合理性。铣削力模型可以满足预测不同加工方向的铣削力的精度要求，可以促进骨科手术中力控制的发展。建立了机器人骨铣削实验平台，模拟了临床手术过程中的铣削过程，并利用加工信号计算了铣削力。最后，根据实验结果，通过实测力与预测力的对比验证了力模型的合理性。铣削力模型可以满足预测不同加工方向的铣削力的精度要求，可以促进骨科手术中力控制的发展。建立了机器人骨铣削实验平台，模拟了临床手术过程中的铣削过程，并利用加工信号计算了铣削力。最后，根据实验结果，通过实测力与预测力的对比验证了力模型的合理性。铣削力模型可以满足预测不同加工方向的铣削力的精度要求，可以促进骨科手术中力控制的发展。