Kinetostatic Modeling of Continuum Delta Robot With Variable Curvature Continuum Joints

Abstract

Continuum robots have attracted lots of attention due to their structural compliance, manipulation dexterity, and design compactness. To extend the application scenarios, a slender continuum robot, the CurviPicker, was developed for low-load medium-speed pick-and-place tasks in a previous study. To improve the payload capacity and positioning accuracy of the CurviPicker, a novel Continuum Delta Robot (CDR) was then proposed with three dual-continuum-joint translators in a preliminary investigation. However, the initial version of the CDR did not fully utilize the bending ranges of its continuum joints. What's more, while being modeled using the constant curvature assumption for the continuum joints, the CDR shows lowered positioning accuracy for heavier objects, as the CDR's continuum joints diverge from the assumed constant curvature shapes. In this paper, the design of the CDR was re-optimized to enable wider bending ranges of the continuum joints (> 90 °) to generate enlarged workspace, taking into considerations several possible structural interferences. Furthermore, a kinetostatic model is derived based on the Cosserat rod theory to reduce the positioning errors caused by the external loads. The experimental result showed that the workspace is enlarged to approximately 9.47 × 107 mm3 compared with the volume of 6.57 × 107 mm3 of the initial version. Within this enlarged workspace, the average positioning error with a 1000-gram load was reduced to 1.93 mm, compared with 4.43 mm obtained by the previous constant curvature assumption.

Compliance and Kinetostatics of a Novel 2PRS-2PSS Compliant Parallel Micromanipulator: Modeling and Analysis

“…Dong et al [20] developed a bridge amplifier and established a motion-statics model based on the compliance matrix method and a dynamics model based on the Lagrange method for the mechanism. Wang et al [21] developed a kinetostatic model utilizing the Cosserat rod theory. The proposed model aimed to minimize positioning errors resulting from external loads.…”