Study on a novel thermal error compensation system for high-precision ball screw feed drive (1st report: Model, calculation and simulation)

2015 ◽  
Vol 16 (9) ◽  
pp. 2005-2011 ◽  
Author(s):  
Zhe-Zhu Xu ◽  
Chang Choi ◽  
Long-jun Liang ◽  
Dong-yang Li ◽  
Sung-Ki Lyu
2013 ◽  
Vol 712-715 ◽  
pp. 1571-1575
Author(s):  
Feng Yang ◽  
Qia Heng Tang ◽  
Yin Biao Guo

In this paper, a thermal error analysis and compensation method for a high precision aspheric measuring platform driven by a linear motor system is presented. After analyzing the heat source of thermal deformation, the thermal deformation of guide is selected to be object, and the thermal analysis method of guide in heat balance state is proposed. According to the motor temperature at different positions, the thermal error curve of guide is obtained through simulation. Modeling the global positioning error of measuring platform and the compensation model of thermal error using polynomial fitting, the thermal error compensation experiments is implemented by applying compensation system of measuring platform's controller. The experimental results show that the maximum positioning error in heat balance state is reduced from 1.5μm to 0.7μm, which verify the validity of thermal error compensation model.


2013 ◽  
Vol 431 ◽  
pp. 132-136
Author(s):  
Ji Zhu Liu ◽  
Wei Wei Yang ◽  
Yang Jun Wang ◽  
Tao Chen ◽  
Ming Qiang Pan ◽  
...  

In the technology of thermal error compensation in positioning platform with large trip and high precision, selecting the temperature measurement points rationally is particular important for successfully establishing the model of compensation. The method uses simulation to track platform heat distribution and thermal deformation under various thermal conditions. Temperature variables are grouped by different surfaces of the platform. Then a degree of grey incidence from grey system theory is introduced to identify the key temperature measurement points of each surface. Through the experiment data of thermal stress coupling analysis on the platform, the degree of correlation between all temperature measurement points and thermal displacement can be solved. The key temperature measurement points are confirmed by the largest value of the degree of correlation of each surface.


2013 ◽  
Vol 655-657 ◽  
pp. 305-309
Author(s):  
Yao Man Zhang ◽  
Ren Jun Gu ◽  
Jia Liang Han

The performances of the high precision turning center will be influenced by the thermal characteristics of the headstock seriously, and accurately predict thermal characteristics of the headstock are helpful to improve the design level. The headstock of a high precision turning center produced by some plant has been regarded as the research objects of the paper. First the steady temperature distribution and thermal deformation of the headstock were calculated based the finite element analysis models of the headstock. Then the temperature sensitive points of the headstock were obtained by using the grey incidence analysis method. Finally the thermal error compensation model was built by using multiple linear regression method. The study lays a foundation for the thermal error compensation of the headstock of the turning center.


Author(s):  
Byung-Sub Kim ◽  
Young-Chan Song ◽  
Chun-Hong Park ◽  
Jong-Kweon Park

High precision machines require very stable operational environment: temperature control and vibration isolation. Tight temperature control for machines usually demand high cost to operate air conditioners. Some of high precision machines require the ambient temperature changes to maintain within ±0.1 degrees. In this paper, we present a thermal error compensation scheme and experimental results for improving machining accuracy of a high precision lathe. The testbed lathe has X- and Z-axes and they are driven by linear motors and hydrostatic oil bearing. Due to the temperature changes of the ambient air and supplied oil to the hydrostatic bearing, thermal deformation is generated and measured to be as much as 200–300 nanometers. To identify the dynamic relations between the temperature changes and the thermal drift, a state-space model is used in which state variables are constructed from the input measured temperatures and the output thermal drift data. The identified model is implemented in a servo control loop and the predicted thermal error is compensated by subtracting the predicted thermal drift from the servo command. In our simulation, a thermal error of 97 nanometers RMS over 3 hours is reduced to 55 nanometers RMS. Experimental results show an average of 24% reduction in thermal drift and support the validity of our approach.


Author(s):  
Jun Zhang ◽  
Bo Li ◽  
Changxing Zhou ◽  
Wanhua Zhao

For semi-closed-loop computer numerical control machine tool, the pitch error of screw caused by thermal expansion can deteriorate the positioning accuracy of ball screw feed drive system. This study presents different prediction models for positioning error of ball screw feed drive system based on the mounting condition, where the total error is separated into geometric error and thermal error. The coefficients in the model are identified using the multiple linear regression method. The prediction model is validated and the error compensation is also done for the X axis of a three-axis computer numerical control milling machine. The test results show that the model developed can well predict the thermal error under any given temperature as well as position during the temperature rising process of ball screw, and it can greatly improve the system positioning accuracy through compensation.


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