A multiscale model for real-time simulation of terrain dynamics is explored. To represent the dynamics on different scales the model combines the description of soil as a continuous solid, as distinct particles and as rigid multibodies. The models are dynamically coupled to each other and to the earthmoving equipment. Agitated soil is represented by a hybrid of contacting particles and continuum solid, with the moving equipment and resting soil as geometric boundaries. Each zone of active soil is aggregated into distinct bodies, with the proper mass, momentum and frictional-cohesive properties, which constrain the equipment's multibody dynamics. The particle model parameters are pre-calibrated to the bulk mechanical parameters for a wide range of different soils. The result is a computationally efficient model for earthmoving operations that resolve the motion of the soil, using a fast iterative solver, and provide realistic forces and dynamic for the equipment, using a direct solver for high numerical precision. Numerical simulations of excavation and bulldozing operations are performed to validate the model and measure the computational performance. Reference data is produced using coupled discrete element and multibody dynamics simulations at relatively high resolution. The digging resistance and soil displacements with the real-time multiscale model agree with the reference model up to 10-25%, and run more than three orders of magnitude faster.
翻译:用于实时模拟地形动态的多尺度模型。 为了代表不同尺度的动态, 模型将土壤的描述组合为连续固态、 不同的粒子和硬体多体。 模型相互动态地结合, 与土流设备相连接。 磁性土壤由连接颗粒和连续固态的混合体代表, 与移动设备和休息土壤作为几何边界。 每个活性土壤区被聚合成不同的体体, 并具有适当的质量、 动力和摩擦- 混合特性, 制约设备的多体动态。 粒子模型参数是预先根据不同土壤的散装机械参数进行校准的。 其结果是, 一种计算高效的模型, 用快速迭代求解器解决土壤运动, 为设备提供现实的力量和动态, 使用一个数字精确度较高的直接解析器。 进行挖掘和推土操作的数值模拟, 以验证模型和测量计算性能。 引用数据, 使用分离的离散元素和多体动力模型模拟, 在相对高分辨率的模型中, 挖掘和土壤流流到10度的频率, 与快速流到10- 和土壤流流流到流到流到10 。