Error modeling and sensitivity analysis of a parallel robot with R -(SS) 2 branches
- PDF / 3,496,112 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 12 Downloads / 196 Views
REGULAR PAPER
Error modeling and sensitivity analysis of a parallel robot with R‑(SS)2 branches Chenhui Huang1 · Fugui Xie1,2 · Xin‑Jun Liu1,2 · Qizhi Meng1 Received: 5 June 2020 / Accepted: 11 October 2020 © Springer Nature Singapore Pte Ltd. 2020
Abstract Parallel robots with R-(SS)2 (R, actuated revolute joint; S, spherical joint) branches are widely used in high-speed sorting. This kind of robot has been developed into a variety of robots with different moving platforms, but the error model is usually only applicable to the specific features of the moving platform. Thus, an adaptable error modeling method is in need. To solve this problem, this paper improves the existing error modeling method by considering the error transmission mode of the dual-moving platform as a common straight line. On this basis, the general form of the error model containing all possible geometric errors is established. Based on the error model and contribution concept, sensitivity indices are defined and the sensitivity is analyzed. Then some atlases are obtained to describe each geometric error’s influence on the moving platform’s pose errors. Accordingly, the linear errors and angular errors that have greater impact on the moving platform’s pose accuracy are identified. Compared with the existing error modeling methods, this improved error modeling method takes the adaptability of the error modeling into account, and can be extended to the specific error modeling of the corresponding robot. Keywords Parallel robot · R-(SS)2 branches · Error modeling · Sensitivity analysis
1 Introduction In food, electronics, pharmaceuticals and various kinds of packaging industries, production lines have been gradually transited from labor-intensive to technology-intensive. The demand for high-speed robots is getting increasingly urgent. Especially for high-speed pick-and-place robots with the ability of three-dimensional translations and one-dimensional rotation (3T1R), which is one of the core equipment to serve the demand (Liu et al. 2016). At the beginning, most of the robots with 3T1R motions are based on the
* Fugui Xie [email protected] * Xin‑Jun Liu [email protected] 1
The State Key Laboratory of Tribology and Tsinghua University (DME)‑Siemens Joint Research Center for Advanced Robotics, Department of Mechanical Engineering (DME), Tsinghua University, Beijing 100084, China
Beijing Key Lab of Precision/Ultra‑precision Manufacturing Equipments and Control, Tsinghua University, Beijing 100084, China
2
serial kinematic mechanisms (SKMs). Compared with the SKMs with 3T1R motions, PKMs might be more suitable for high-speed pick-and-place operation due to the advantages of high stiffness, low moving inertia, compact structure, etc. (Fichter 1986). Therefore, high-speed PKMs gradually comes into researchers’ view. Dr. Clavel invented the Delta mechanism (Clavel 1990), which consists of three branches of the same R-(SS)2 (R, actuated revolute joint; S, spherical joint) structure to realize three-dimensional high
Data Loading...
