# Operational Temperature Effect on Positioning Accuracy of a Single-Axial Moving Carrier
## 1 Introduction
It was found that the thermal deformation brought on by environmental temperature variations increased with the increase in the rotating speed of the spindle. Therefore, environmental temperature control is required to improve the precision of rotating spindles as well. [PERSON] et al. [17] monitored the spindle movement over days rather than hours to measure daily cyclic environmental temperature fluctuations and associated errors. They provided information about cyclic environmental fluctuations and drifts with a 50% reduction in errors over a 65 h test and drew attention to the detrimental amount of machine downtime for thermal characterization tests. However, the daily environmental temperature variations in different seasons in one year may totally differ, especially in summer and winter. The effect of daily temperature variations in terms of different seasons has not been investigated well in the literature. Environmental temperature variations can affect the energy consumption of a machine tool as well. [PERSON] et al. [18] also argued that a location with a different temperature was found to have a significant influence on environmental impacts, resulting in changes in the annual energy consumption relative to the baseline that ranged from \(-10\%\) to 8%. [PERSON] et al. [19] analyzed the lifetime energy consumption of a machine tool, including transportation, material inputs, and facility input. The results of their analysis provide greater value than previous work because they highlighted the areas with the greatest opportunity for energy optimization. The results also indicate that environmental impacts consume a large portion of the lifetime energy consumption. In terms of the studies on environmental temperature control, [PERSON] and [PERSON] [20] noted how changes in the locations of air openings can affect air velocity and air distribution in an experimental area. [PERSON] et al. [21] probed into the temperature homogeneity control of greenhouses via computational fluid dynamics (CFD) and proposed a factor-optimized control based on the design of experiments concerning a CFD simulation model. Thus, they acquired the best combination of environmental control factors through a relatively small number of computational simulations and analyses. [PERSON] [22] used numerical analyses and CFD software to simulate the air flow organization at a constant temperature in a humidity chamber. A mathematical model of the temperature control chamber was established in the experiments based on system identification theories. Applications of proportional-integral-derivative (PID) control theories in temperature control chambers have also been investigated. In the past, the effect of flow patterns in an environmental control chamber on manufacturing precision has also not been investigated. For high-precision machine tools, the requirement of current positioning accuracy is less than 10 \(\upmu\)m in industry. In terms of environmental conditions, environmental temperature variations for high-precision machines in industry are usually required to be in the range of \(-0.5\) to \(0.5\)\({}^{\circ}\)C. In the past, most literature has investigated thermal compensation to reduce thermal deformation from the heat sources in the machines. Thermal deformation of the structure coming from the ambient temperature variations needs to be investigated further. The main purpose of thermal compensation is to reduce thermal deformation caused by heat sources, for example, the spindle. However, thermal deformation of a structure coming from the ambient temperature variations cannot be compensated for by existing thermal compensation designs. In the past, thermal deformation resulting from daily ambient temperature variations, in terms of different seasons and the effect of flow patterns around the moving machines on positioning accuracy, has not been experimentally investigated. That is the reason why this paper investigates the ambient temperature's effect on the positioning accuracy of a moving carrier.