A method to improve position accuracy for the dual-drive feed machines by state-dependent friction compensation

Abstract

Due to high stiffness and quick response, dual-drive feed machines (DDFMs) are widely used in many precision CNC machines. The tracking errors of the two feed drives directly determine the machines’ accuracy. The performance of the position accuracy can be easily affected by the difference in the friction dynamic characteristics of the two axes. This paper proposes the state-dependent friction compensation (SFC) as an improved DDFMs error compensation method that can achieve better accuracy under unequal friction on the two feed drives. It is theoretically analyzed the influence of friction on the transmission stiffness of DDFMs. Moreover, the effects of time-varying factors (feed rates and mechanical structures) on the friction of dual axes are discussed. The innovation of the paper is that the SFC can adaptively take into account the influence of the variable dual-drive structure and feed rate on DDFMs’ position accuracy, and the compensation method combined with cross-coupled strategy is suitable for general dual-drive structure. Simulation and experiment results show that the proposed method can effectively improve the synchronization accuracy and tracking accuracy in a variety of feed operations (different feed rates, starting, and reversing).

The Structure-Dependent Dynamic Performance of a Twin-Ball-Screw Drive Mechanism via a Receptance Coupling Approach

“…Therefore, the torsional vibration of the entire BS (F A1B1−t and F A2B2−t ) is obtained by connecting the FRF matrix in segments A1-B1 for the first motor and A2-B2 for the second motor. Moreover, the optimal value of the torsional vibration of the two ball screws can be obtained in Equation (14). Note that the labels J1 and J2 are represented in Equation (11), where d stands for the diameters of the BSs.…”

“…Various methods, such as lumped parameters, finite elements, and hybrid approaches, have been employed by different researchers to analyze the dynamic behaviors of the TBSDM [10][11][12][13]. Liu Qi et al [14] adopted the lumped-parameter technique to create a thorough dynamic model of the TBSDM by considering the contact stiffness of kinematic joints. It has been found that the inherent frequency of the TBSDM is greater during motion than when it is static.…”

Analysis of Dual-Driven Feed System Vibration Characteristics Based on Computer Numerical Control Machine Tools: A Systematic Review

“…Dual-driven and single-driven feed systems are the mechanisms various machines apply to transport materials or components through a processing or assembly line. Several studies have been offered to provide a comprehensive understanding of DDFS [16,17,[29][30][31]. While comparing these two different feeding systems, as shown in Table 1, this research considers the number of motors, the control, the speed, the structural complexity, and the load distribution.…”

“…A unidirectional dual-feed servosystem of DDFS, shown in Figure 1 [13,14], features excellent precision and stability due to the dual-drive structure's powerful force, low inertia, substantial transmission stiffness, and broad control frequency. DDFS is extensively applied in high-precision manufacturing machinery, including gantry-type tools and rectangular coordination robotics [15][16][17]. Due to its potential to considerably affect the control performance, machining precision, and stability of massive gantry-type equipment, the twin ball screw feed system's (TBSFS) dynamic features occupy an enormous part of increasing the positioning and manufacturing consistency [18][19][20][21][22][23].…”