scholarly journals INFLUENCE OF LINEAR FEED DRIVE CONTROLLER SETTING IN CNC TURNING LATHE ON THE STABILITY OF MACHINING

2019 ◽  
Vol 19 (2) ◽  
pp. 18-31 ◽  
Author(s):  
Jan GRAU ◽  
Matej SULITKA ◽  
Pavel SOUCEK
Keyword(s):  
Simulation Model ◽  
Dynamic Compliance ◽  
Ball Screw ◽  
Depth Of Cut ◽  
Cnc Turning ◽  
Feed Drive ◽  
Drive Control ◽  
The Stability ◽  
Ball Screw Drive ◽  
Stability Limits

The paper deals with the influence of linear feed drive controller setting of a CNC turning lathe on the stability of machining. A coupled simulation model of feed drive control and ball screw drive mechanics with a transmission belt was created and validated by the feed drive diagnostic measurements. The influence of drive control on the overall dynamic compliance at the TCP and the limits of stable depth of cut was examined. Impact of the feed drive actual kinematics configuration on the stability limits was studied as well.

scholarly journals The Influence of Servo Drive Control on the NC Vertical Milling Machine Dynamic Compliance

2020 ◽  
Vol 4 (4) ◽  
pp. 111
Author(s):  
Jan Grau ◽  
Pavel Souček ◽  
Matěj Sulitka
Keyword(s):  
Machine Tool ◽  
Position Control ◽  
Dynamic Compliance ◽  
Numerical Control ◽  
Machining Process ◽  
Servo Drive ◽  
Compliance Matrix ◽  
Mechanical Structure ◽  
Feed Drive ◽  
Drive Control

A model Numerical Control (NC) machine tool dynamic compliance is analyzed, including the influence of its mechanical structure and position control feed drive algorithms. The dynamic model of the machine tool is divided into two main parts, which are closest to the machining process. First, the milling head assembly group is presented as a system of one mass oscillating in a 2D plane and 3D space. Second, the motion axes assembly group, XY cross table with linear feed drive, is presented. A square 2×2 dimension matrix of the total dynamic compliance is evaluated within the feed drive control system included. Partial elements of the mechanical structure dynamic compliance matrix of the general N×N dimension are contained in the total dynamic compliance matrix.

scholarly journals Disturbance of the Regenerative Effect by Use of Milling Tools Modified with Asymmetric Dynamic Properties

2020 ◽  
Vol 4 (3) ◽  
pp. 67
Author(s):  
Jonas Baumann ◽  
Andreas Wirtz ◽  
Tobias Siebrecht ◽  
Dirk Biermann
Keyword(s):  
Dynamic Properties ◽  
Constant Width ◽  
Chip Thickness ◽  
Stability Limit ◽  
Dynamic Compliance ◽  
Depth Of Cut ◽  
Regenerative Effect ◽  
The Stability ◽  
Tool Shank ◽  
Milling Tools

Milling processes are often limited by self-excited vibrations of the tool or workpiece, generated by the regenerative effect, especially when using long cantilevered tools or machining thin-walled workpieces. The regenerative effect arises from a periodic modulation of the uncut chip thickness within the frequencies of the eigenmodes, which results in a critical excitation in the consecutive cuts or tooth engagements. This paper presents a new approach for disturbing the regenerative effect by using milling tools which are modified with asymmetric dynamic properties. A four-fluted milling tool was modified with parallel slots in the tool shank in order to establish asymmetric dynamic characteristics or different eigenfrequencies for consecutive tooth engagements, respectively. Measurements of the frequency response functions at the tool tip showed a decrease in the eigenfrequencies as well as an increase in the dynamic compliance in the direction of the grooves. Milling experiments with a constant width of cut and constantly increasing axial depth of cut indicated a significant increase in the stability limit for the specific preparations of up to 69%.

The Application of a Grating Tiling Device with Parallel Mechanism in an Inertial Confinement Fusion (ICF) System

2013 ◽  
Vol 579-580 ◽  
pp. 373-380
Author(s):  
Zhong Xi Shao ◽  
Wei Jiang Zhou ◽  
Hong Ya Fu
Keyword(s):  
Inertial Confinement Fusion ◽  
Parallel Mechanism ◽  
Pulse Compression ◽  
Correction Method ◽  
Inertial Confinement ◽  
Positioning Accuracy ◽  
Feed Drive ◽  
Drive Control ◽  
Confinement Fusion ◽  
The Stability

The size of pulse compression gratings (PCG) is very big in the ICF system, so we obtained a large size grating by mechanically stitching small caliber gratings. And we design the splicing mechanism to be a 5-DOF Parallel Mechanism with macro/micro dual feed drive control to meet the requirements of large travel, high precision, high stability and 5-DOF of the grating tiling. The macro-moving part is designed to be the 5PTS-1PPS parallel mechanism, using the Feed Mechanism of ballscrew with Stepper Motor Drive.The micro-moving part is designed to be 5TSP-1PPS parallel mechanism, using the feed mechanism of Flexure Hinge with Piezoelectric Ceramic Actuator. We derived control algorithm of parallel mechanism by the method of the Kinematics of parallel mechanism. We analyzed the systematic error and put forward the error correction method in order to improve the positioning accuracy. At last, we designed an optical detecting system to evaluate the feasibility of this scheme, the positioning accuracy and the Stability of parallel Splicing structure. The results showed that the mechanism performance can meet the requirements of grating tiling work.

scholarly journals An Electromechanical Co-Simulation Model Based on Lumped Parameter Model of Ball Screw Feed Drive System

2018 ◽  
Vol 237 ◽  
pp. 03007
Author(s):  
Liang Luo ◽  
Weimin Zhang ◽  
Haonan Sui ◽  
Jürgen Fleischer
Keyword(s):  
Simulation Model ◽  
High Speed ◽  
Drive System ◽  
Lumped Parameter Model ◽  
Ball Screw ◽  
Feed System ◽  
Feed Drive ◽  
Lumped Parameter ◽  
Feed Drive System ◽  
Screw Feed

The continuous search for efficiency put forward higher requests to the machine tool for high speed and high acceleration, which makes the large-size and lightweight-designed feed drive system more likely to produce vibration during high-speed and high-acceleration feed operation. Ball screw feed system is the most widely used linear drive system in the field of industrial automation. Electromechanical Co-Simulation for ball screw feed drive dynamics is an important technique for solving vibration problems occurs in the feed motion. In view of the shortcomings of the current dynamic simulation model in the study of vibration of ball screw feed drive system, taking a ball screw feed drive system test bench as an example, an electromechanical co-simulation model based on the lumped parameter model of ball screw feed drive system was built up in this paper. Firstly, based on the axial and rotation vibration integrated dynamic modeling method of ball screws, the lumped parameter model of ball screw feed system was established. Secondly, through the integration of the simulation model of semi-closed-loop cascade control system and the lumped parameter model of ball screw feed drive system, an electromechanical co-simulation model was built up. Simulation result shows that, the co-simulation model of ball screw feed drive system can predict the vibration occurs in the feed operation caused by the servo controller, ball screw feed system or the coupling between them.

Dynamic Simulation and Cutting Conditions Optimization of Tee Slot Milling Based on CutPro Software

2009 ◽  
Vol 407-408 ◽  
pp. 589-593
Author(s):  
Zhong Qun Li
Keyword(s):  
Dynamic Simulation ◽  
Target Function ◽  
Experimental Tests ◽  
Optimization Method ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Slot Milling ◽  
Milling Operation ◽  
The Stability ◽  
Stability Limits

. Based on the dynamic simulation module of CutPro, the dynamic cutting forces and chatter limits for tee slot milling were predicated by setting the geometry of a tee slotting cutter. The chatter stability lobes under a given axial depth of cut are obtained by further programming, which is essential for chatter-free tee slot milling. A methodology of cutting conditions optimization for tee slot milling is presented, in which the minimal cutting time is used as the target function and the stability limits are introduced into the constraint conditions to reflect the vibration characteristics of milling operation. This optimization method has been validated by experimental tests.

Stability as a constraint in sagittal plane human force exertion modeling

1998 ◽  
Vol 1 (1) ◽  
pp. 23-39
Author(s):  
Carter J. Kerk ◽  
Don B. Chaffin ◽  
W. Monroe Keyserling
Keyword(s):  
Muscle Strength ◽  
Ankle Joint ◽  
Coefficient Of Friction ◽  
Sagittal Plane ◽  
Biomechanical Model ◽  
Whole Body ◽  
The Stability ◽  
Joint Center ◽  
Static Conditions ◽  
Stability Limits

The stability constraints of a two-dimensional static human force exertion capability model (2DHFEC) were evaluated with subjects of varying anthropometry and strength capabilities performing manual exertions. The biomechanical model comprehensively estimated human force exertion capability under sagittally symmetric static conditions using constraints from three classes: stability, joint muscle strength, and coefficient of friction. Experimental results showed the concept of stability must be considered with joint muscle strength capability and coefficient of friction in predicting hand force exertion capability. Information was gained concerning foot modeling parameters as they affect whole-body stability. Findings indicated that stability limits should be placed approximately 37 % the ankle joint center to the posterior-most point of the foot and 130 % the distance from the ankle joint center to the maximal medial protuberance (the ball of the foot). 2DHFEC provided improvements over existing models, especially where horizontal push/pull forces create balance concerns.

scholarly journals Derived Interaction Parameters for the TSAI-WU Tensor Polynomial Theory of Strength for Composite Materials

2001 ◽  
Author(s):  
Steven J. DeTeresa ◽  
Gregory J. Larsen
Keyword(s):  
Hydrostatic Pressure ◽  
Fiber Composite ◽  
Strength Criterion ◽  
Test Methods ◽  
Standard Test ◽  
Transverse Compression ◽  
Strength Parameters ◽  
Carbon Fiber Composite ◽  
The Stability ◽  
Stability Limits

Abstract It is shown that the two interactive strength parameters in the Tsai-Wu tensor polynomial strength criterion for fiber composites can be derived in terms of the uniaxial or non-interacting strength parameters if the composite does not fail under practical levels of hydrostatic pressure or equal transverse compression. Thus the required number of parameters is reduced from seven to five and all five of the remaining strength terms are easily determined using standard test methods. The derived interactive parameters fall within the stability limits of the theory, yet they lead to open failure surfaces in the compressive stress quadrant. The assumptions used to derive the interactive parameters were supported by measurements for the effect of hydrostatic pressure and unequal transverse compression on the behavior of a typical carbon fiber composite.

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