TY - JOUR

T1 - Investigation and strategies for precision of miniaturized robots with micro gears

AU - Burisch, Arne

AU - Raatz, Annika

PY - 2011/9/27

Y1 - 2011/9/27

N2 - Purpose - Economic, flexible and efficient micro production needs new miniaturized automation equipment (desktop factories). Micro assembly processes make demands on precision of miniaturized robots used in desktop factories and the driving concepts, as well as miniaturized machine elements. The purpose of this paper is to investigate miniaturized drives using micro harmonic drive gears, which are promising driving concepts. Design/methodology/approach - The analysis of the miniaturized precision robot Parvus (using micro harmonic drive gears) shows a good repeatability but also room for improvement concerning the path accuracy. Thereby the transmission error of the micro gears is identified as main disturbing influence concerning the robot's precision characteristics. Owing to the size reduction of the micro harmonic drive gear and the slightly different working principle compared to larger harmonic drive gears, the transmission error are more pronounced. Therefore, it is necessary to discuss approaches to compensate for this effect. Findings - A very promising approach is the use of a simplified model of the kinematic error within the robot control to compensate for this disturbing effect. Measurement data of the transmission error is mathematically transformed into the frequency domain and filtered to the most important frequency modes of the function. These modes are used to build up a simplified mathematic model of the gear transmission error. A final test using this model as compensation function demonstrates that it is possible to reduce the transmission error of the micro gears by more than 50 percent. Originality/value - The paper presents the first investigation into compensation of the transmission error of micro harmonic drive gears.

AB - Purpose - Economic, flexible and efficient micro production needs new miniaturized automation equipment (desktop factories). Micro assembly processes make demands on precision of miniaturized robots used in desktop factories and the driving concepts, as well as miniaturized machine elements. The purpose of this paper is to investigate miniaturized drives using micro harmonic drive gears, which are promising driving concepts. Design/methodology/approach - The analysis of the miniaturized precision robot Parvus (using micro harmonic drive gears) shows a good repeatability but also room for improvement concerning the path accuracy. Thereby the transmission error of the micro gears is identified as main disturbing influence concerning the robot's precision characteristics. Owing to the size reduction of the micro harmonic drive gear and the slightly different working principle compared to larger harmonic drive gears, the transmission error are more pronounced. Therefore, it is necessary to discuss approaches to compensate for this effect. Findings - A very promising approach is the use of a simplified model of the kinematic error within the robot control to compensate for this disturbing effect. Measurement data of the transmission error is mathematically transformed into the frequency domain and filtered to the most important frequency modes of the function. These modes are used to build up a simplified mathematic model of the gear transmission error. A final test using this model as compensation function demonstrates that it is possible to reduce the transmission error of the micro gears by more than 50 percent. Originality/value - The paper presents the first investigation into compensation of the transmission error of micro harmonic drive gears.

KW - Compensation

KW - Desktop factory

KW - Harmonics

KW - Kinematics

KW - Micro gears

KW - Miniaturization

KW - Precision robot

KW - Transmission error

UR - http://www.scopus.com/inward/record.url?scp=80053527622&partnerID=8YFLogxK

U2 - 10.1108/01445151111172899

DO - 10.1108/01445151111172899

M3 - Article

AN - SCOPUS:80053527622

VL - 31

SP - 319

EP - 328

JO - Assembly automation

JF - Assembly automation

SN - 0144-5154

IS - 4

ER -