Kinematic performance evaluation of high-speed Delta parallel robots based on motion/force transmission indices

Optimization design using a global and comprehensive performance index and angular constraints in a type of parallel manipulator

“…In the following discussion, pressure angle g is referred to as the first type of pressure angle among the limbs. Based on the calculation and analysis, a type of new pressure angle b i among the limbs is proposed by equation (19) as the second type of pressure angle among the limbs…”

“…It is clearly demonstrated that if the maximum of the corresponding angle range (b 0 i ) satisfies the requirements, all angles of the angle range (including b i ) can also guarantee the transmission performance. To better analyze the second type of pressure angle b i among the limbs, we substitute equation (19) for equation (21) in the theory, which will also make the physical meaning more explicit and guarantee the identical transmission capacity among the limbs. The second type of pressure angle among the limbs is suitable for almost all types of 4-DOF parallel manipulators.…”

“…Huang et al 18 optimized their parallel mechanism with the genetic algorithm considering the workspace and global performance indexes of stiffness as well as the dexterity as the performance indices. Brinker et al 19 aggregated the transmission and constraint characteristics into a single index, and the validity and applicability for kinematic performance optimization was proven. Another 2-DOF parallel mechanism was analyzed in the study by Huo et al, 20 where non-dominated sorting genetic algorithm II was utilized to optimize the design dimensional parameters by means of three global indices.…”

Quintic Pythagorean-Hodograph Curves Based Trajectory Planning for Delta Robot with a Prescribed Geometrical Constraint

“…In the past three decades, the use of parallel manipulators [1][2][3] has been increased in industrial and academic fields [4][5][6], especially in the fields of product transportation and classification, motion simulators, multi-dimensional force sensors, micro-operation consoles, precision positioning devices, etc., for their relative features like superior rigidity, higher accuracy, lighter mechanical construction, resulting in a homogenous and symmetric force/torque distribution, easier inverse kinematic calculations [7][8][9]. In recent years, researchers are increasingly inclined to concentrate on three translational degree-of-freedom (DOF) parallel manipulator [10][11][12][13].…”

“…As we all know, the Delta parallel robots [14,15] have effective mechanical structures [16], which makes the solution of its forward kinematic simpler. Because of its good characteristics, the Delta robot is often applied for high-speed pick-and-place applications with light-weight objects [9,17]. Pick-and-place is considered as a commonly used action [18] in palletizing and sorting in which objects are collected in an orderly manner and then put in their corresponding locations [19], however, due to the geometrically complicated surroundings, planning the robot's pick-and-place movement is often difficult.…”