Abstract: Aiming at the operation demands grasping the thin-wall fragile parts in industrial production， an inner braced working manipulator configuration with finger-palm collaborative features was proposed. In order to find the appropriate operational parameters of the manipulators fingers， and explore the stress change law on contact-collision for the grasping processes， the finite element model of the finger parts for the manipulator was established by integrating HyperMesh and LS-PrePostto model. After applying the corresponding constraints， loads and contact types to the finite element model， the stress and strain cloud images for the fingers and the fragile parts on the contact-collision processes were obtained by calculation. The simulation results show that the stresses of the fragile parts increase linearly with the increasing of the fingers impact speeds. When the speed changes from 0.5 to 2.5 mm/ms， the stress increases to 3 to 4 times the original. With the increasing of the wall thickness of fragile parts， the fragile parts stresses decrease gradually. The stress changes obviously at the stage of thin wall thickness， the average stress variation of the wall thickness of 0.51.0 mm is 67 times that of the wall thickness of 1.02.5 mm. When the manipulator applies different acceleration at the contacting fragile parts moment， as the acceleration increases， the contact stress increases accordingly， the average stress change for acceleration of 1.02.5 mm/ms2 is 89 times that of the acceleration of 0.51.0  mm/ms2. According to the existing simulation results， the Kriging agent model is established to calculate the prediction model of the contact stresses under the different wall thickness and grasping speed， which establishes the foundation for determining the grasping parameters of the manipulators， designing and optimizing the finger structures under different conditions. By constructing an experimental system， the simulation results were verified experimentally， and the correctness of the simulation results was proved. 

Key words:  , inner braced manipulator； thin-walled fragile part； integrated modeling； contact-collision； impact simulation

摘要： 针对工业生产中抓取薄壁易碎件的作业需求，提出了一种具有指掌协同特征的内撑式机械手构型。为了寻找合适的机械手手指作业参数，探索抓取过程中接触-碰撞时应力的变化规律，采用HyperMesh、LS-PrePost等软件集成建模的方法建立了机械手指的有限元模型，对有限元模型施加相应的约束、载荷、接触类型后，计算得到了手指与易碎件接触碰撞过程中的应力、应变云图。仿真结果表明：随着手指冲击速度的增大，易碎件所受的应力呈线性增大。速度在0.5～2.5 mm/ms变化时，应力增大为原来的3～4倍；随易碎件壁厚的增大，易碎件所受的应力逐渐减小。而在较小壁厚阶段，应力变化明显，壁厚0.5～1.0 mm时的平均应力变化是壁厚1.0～2.5 mm时应力的6～7倍；在机械手抓取易碎件的碰撞瞬间施加不同的加速度时，随加速度的增大，接触应力也相应增大，加速度在1.0～2.5 mm/ms2时的平均应力变化是加速度0.5～1.0 mm/ms2时的8～9倍。根据已有的仿真结果，通过建立Kriging代理模型，计算得到的不同壁厚、抓取速度条件下接触应力大小的预测模型，为确定不同状态下的机械手抓取参数、设计和优化手指结构建立了基础。通过构建实验系统，对相关仿真结果进行了实验验证，证明了仿真结果的正确性。

关键词: 内撑式机械手, 薄壁易碎件, 集成建模, 接触-碰撞, 冲击仿真