Design of robot gripper jaws based on trapezoidal modules

Assembly line reliability can be increased if grippers are carefully designed to capture and align parts. Jaw design depends on the geometric and mechanical properties of the part as well as its desired orientation. We propose a class of modular jaws based on rapidly machineable trapezoidal modules. An optimal jaw design is an arrangement of trapezoidal jaw modules that maximizes contacts between the gripper and the part at its desired final orientation over the constraints that: the jaws will capture and rotate the part to its desired orientation and achieve a form-closure grasp. Given the n-sided 2D convex projection of an extruded polygonal part, we develop an implemented O(n⁵) algorithm to find the optimal jaw design. The algorithm combines toppling, jamming, liftoff, accessibility, and form-closure analysis. We verify resulting designs by physical experiments.