Abstract:In the initial design stage of machine tools, only the information of tolerance of machine tools’ key components is known. Since geometric errors of machine tools can play the role of guidance for the accuracy design of machine tools, geometric errors were obtained only by making use of design experiences. Hence, it is important to predict the geometric errors accurately in the design process of new machine tools. A new approach to predict geometric error based on tolerance of machine tools’ guideways was proposed. Firstly, the mapping relationship between tolerance and profile errors of machine tools’ guideways was established by utilizing the truncated Fourier series function to fit curve of guideways surface profile. Meanwhile，the mapping relationship between profile errors and geometric errors of guideways was established. Since profile errors are regarded as a bridge between tolerance and geometric errors of machine tools’ guideways, geometric errors prediction model based on tolerance of guideways was proposed. Then, simulation verification was carried out. Simulation results showed that the range of the predicted kinematic error (positioning error, y direction and z direction straightness error, roll error, pitch error, and yaw error) is 17.12 μm, 56.57 μm, 70.71 μm, 28.28 μrad, 141.42 μrad, and 113.14 μrad, respectively. Finally, a measuring experiment was carried out by using a dual-frequency laser interferometer. The measured and identified results could be fitted precisely by Fourier curve fitting method. The fitting results showed that the range of the measured kinematic errors was 16.96 μm, 59.43 μm, 68.63 μm, 28.65 μrad, 135.40 μrad, and 111.58 μrad, respectively. By means of contrasting the measured results and predicted results, residual errors were no more than 10% of the measured results. Therefore, in the design stage of machine tools, this method is effective enough for predicting geometric errors and can be used to replace the measurement of geometric errors, and lays a foundation for designers. And its basic idea can be applied to other type of guideways.