Robot acceleration is the bottleneck for high-speed pick-and-place operations.In this paper,the extreme acceleration at null velocity is proposed to characterize the acceleration capability.Detailed dynamic model of the V3 robot is developed for computing the extreme acceleration.Since each subchain of the robot is comparable to a cantilever beam structure, its bending deflection may be considerable and thus leads to manipulation failure.The bending stiffness is thus proposed characterized by the bending deflection.Combining the acceleration and the bending stiffness with kinematic indices of velocity, accuracy, and dexterity, the optimal design problem is formulated to maximize the dextrous workspace having specified good performance.The optimal structure shows greatly improved performance in workspace, velocity, acceleration, and accuracy.