A Comparison of Linear and Conventional Electromechanical Dives

doi:10.1016/S0007-8506(07)63241-7

CIRP Annals

Volume 47, Issue 2, 1998, Pages 541-548

https://doi.org/10.1016/S0007-8506(07)63241-7 Get rights and content

Abstract

This publication deals with advantages and characteristics of linear drives in comparison with the conventional electromechanical drives and discusses suitable applications. Due to their high cost per axis, linear drives are mainly appropriate for some special applications such as high speed machining.

References (18)

G. Pritschow et al.
Direct Drives for High-Dynamic Machine Tool Axes
Annals of the CIRP
(1992)
P. van den Braembussche et al.
N.N., Translatorische Direktantriebe in der Werkzeugmaschine Gebr. Heller Maschinenfabrik,...
R. Hagl
G. Pritschow
Increasing Accuracy through Utilization of Linear Direct Drives
Manufacturing Systems
(1996)
M. Week et al.
Statische und dynamische Steifigkeit von linearen Direktantrieben
Antriebstechnik
(1997)
G. Pritschow
On the Influence of the Velocity Gain Factor on the Path Deviation
Annals of the CIRP
(1996)
Hiller, B., Hochgenaue Messung von Zustandsgrö-ßen an NC-Achsen. Lageregelseminar 1996, FISW...
Sogabe, M., Linear Motor for Machine Tool. FANUC...

There are more references available in the full text version of this article.

Cited by (93)

Thermal error modelling for linear motor feed drive system considering multi-field coupling of electromagnetic-thermal-flow
2023, Case Studies in Thermal Engineering
Thermal error is a crucial factor affecting the accuracy of linear motor feed drive systems (LMFDS). To improve the prediction accuracy, a thermal error model for LMFDS considering the multi-field coupling of electromagnetic-thermal-flow (EM-TF) is proposed. Firstly, the thermal error mechanism is analyzed and the temperature control equation of LMFDS is deduced under multi-field coupling of electromagnetic, thermal, and flow fields. Then, aiming at the difficulty to solve the control equation directly, an indirect solution method is proposed. According to the simplification conditions of the actual process, the control equation is divided into three stages and then recoupled together. Finally, a prediction model for LMFDS thermal error is established based on the temperature equation and thermal expansion theory. Compared with traditional models, the proposed model has a good physical meaning and prediction accuracy. In addition, experiments have proven that the model can automatically adjust the linear and nonlinear intervals, fully reflecting the entire changing process of thermal error in LMFDS.
Controller design for high-speed, ultra-precision positioning of a linear motion stage on a vibrating machine base stage control on a vibrating base
2023, Precision Engineering
Citation Excerpt :
Various control methods have been applied to feed drive systems [8]. Traditional controllers such as P-PI and PID controllers can be tuned easily and used widely in the feed drive system [9,10]. However, it is difficult for traditional controllers to suppress the machine's relative vibration, including the machine base [11].
This paper presents a high-speed, ultra-precision point-to-point position control system design. It addresses precision stages with unknown characteristics, affected by machine base vibration and system effectiveness. The design is based on the nominal characteristic trajectory following (NCTF) control method, which can provide ultra-precision position control performance for the precision stages without accurate dynamic models. However, conventional NCTF control systems neither provide sufficient vibration suppression nor exhibit suitable vibration suppression characteristics. The position control performance is deteriorated by the machine base vibration. To overcome this problem, a procedure for incorporating a bandpass filter and derivative compensator in the NCTF control system is proposed and designed. These compensators exhibit high vibration suppression ability when combined, rather than when used individually. Additionally, they can be easily designed without any accurate dynamic model. The effectiveness of the compensator combination was first investigated using a linear model and subsequently experimentally verified. Using the proposed procedure, a control system was designed for the precision stage with friction characteristics on the vibrating machine base. The designed control system suppresses the residual vibration immediately after the target value becomes constant, and the error converges below 50 nm within 80 ms.
Dynamic compliance attenuation in ball screw drives through model-based active damping of multiple vibration modes
2022, CIRP Annals
Citation Excerpt :
Increased BW [2] enhances the dynamic accuracy in responding to faster tool trajectory commands with higher frequency content, and when implemented judiciously can also reduce the dynamic compliance for a target frequency range. Yet, the vibrations of a feed drive assembly, especially for ball screw drives (BSDs), pose a major limitation on the achievable BW [2]. The proposed controller has been developed and tested on the setup in Fig. 1a, comprising a 20 mm diameter 20 mm lead ball screw drive (THK BNK 2020-3.6G0+1220 LC5-Y), driven by a 3 kW synchronous motor (Omron R88M-K3K030H) powered through a 3-phase linear amplifier (Varedan LA-1555T).
This paper presents a new control structure for ball screw drives (BSDs), which achieves position tracking through an outer loop, and active vibration damping for dynamic stiffness enhancement through an inner loop based on $H_{2}$ -synthesis. As an advancement over earlier BSD control methods with active damping, the proposed technique is able to consider multiple vibration modes simultaneously, rather than only the most dominant (axial) vibration mode. The end result is 2–3 times reduced dynamic compliance over a wide frequency range, compared to approaches like P-PI position-velocity cascade control (industry standard) and pole-placement control (PPC), and comparable or better tracking accuracy.
Preload monitoring of single nut ball screws based on sensor fusion
2021, CIRP Journal of Manufacturing Science and Technology
Unplanned machine downtimes lead to higher costs through reduced productivity. Machine availability is amongst others limited by the failure of wear-induced preload loss of ball screws. Therefore, attempts are made to monitor the preload. The high complexity and required robustness of preload monitoring leads to a low spreading in industry so far. This paper investigates the capability of sensor fusion based on principal component analysis to monitor preload loss of single nut ball screws. Features are investigated using different preload levels of the ball screw by selecting different ball-diameters. It is shown that this approach reliably detects the preload levels.
A novel cascade control principle for feed drives of machine tools
2018, CIRP Annals
Most feed drives in machine tools are designed using ball screw drives. The bandwidth of such drives with conventional PPI control principle is limited by the first natural frequency of mechanical transmission elements. A novel feedback control principle is presented to improve feed drive dynamics. It is cascade structured and consists of a weakly set motor speed controller, a disturbance observer with the feedback velocity of machine table and a PD position controller. This principle increases the bandwidth of the position loop over 200% without any extra sensor or actuator. Experimental results validate the effectiveness and robustness of this principle.
Virtual metrology frame technique for improving dynamic performance of a small size machine tool
2017, Precision Engineering
This paper presents a novel concept, a virtual metrology frame, for enhancing the dynamic performance of a machine tool with a flexible structural frame. The dynamic properties of a machine are directly affected by the stiffness of its frame, and its reference system; thus, by having an unstressed metrology frame, superior dynamic capabilities can be achieved. The developed concept does not require physical components associated with metrology frame; hence it is ideal for machine tools with requirements for small footprint and ultra-precision performance. The concept relies on an accelerometer based dynamic displacement feedback technique, where the accelerometer is used as a precision frame displacement sensor. The concept does not require a complex controller, and was realized in an off-the-shelf CNC controller. The concept was demonstrated on a linear motion system, a simplified version of a compact size CNC machine, and its servo bandwidth and dynamic stiffness were improved by 36% and 70% respectively, which are the key parameters for improving the machining accuracy.

View all citing articles on Scopus

View full text

Keynote PapersA Comparison of Linear and Conventional Electromechanical Dives

Abstract

Annals of the CIRP

Increasing Accuracy through Utilization of Linear Direct Drives

Manufacturing Systems

Statische und dynamische Steifigkeit von linearen Direktantrieben

Antriebstechnik

On the Influence of the Velocity Gain Factor on the Path Deviation

Annals of the CIRP

Keynote Papers
A Comparison of Linear and Conventional Electromechanical Dives