• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1063-1065
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• 1993

LDM, easy to minute position control, is using as X-Y plotter or other recording instruments. Brushless LDM has better properties than the conventional Brush type LDM in many aspects. This paper presents magnetic flux density distribution by FEM and a way to reduce thrust force ripple particurary in low speed drive. And we apply this method to a real mode of LDM. This LDM is operated by IBM-PC host computer and uses rotary encoder to make position signal.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.16-18
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• 1998

In this paper, a control method based on finite element analysis is presented to reduce the thrust ripple of the permanent magnet linear synchronous motor (PMLSM). In the control method, additional compensation current is added to the conventional control current according to the position of mover. The exact value of the compensation current is calculated from finite element analysis. To conform the validity of the presented method, a test set is built and experiments are performed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.358-362
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• 2004

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.33-35
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• 2001

Linear Pulse Motor(LPM) has a thrust ripple which is causing vibration. To reduce the vibration, Microstep driving method is adopted. We manufactured Microstep drive, and drove LPM with that, and then investigated the characteristics of thrust force.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.1
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• pp.31-35
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• 2005

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.121-123
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• 2006

In this paper, the notch of teeth and skew of permanent magnet are used to reduce the detent force caused by slot-teeth structure. Also, the shape of permanent magnet is optimized to reduce the detent forceowing to flux hannonics components of permanent magnet. As a result, thrust is decrease about 2[%]. But, the distortion ratio of thrust is decreased from 1.04[%] to 0.75[%]. And, the ripple ratio of thrust is decreased from 2.6[%] to 1.65[%].

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2146-2148
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• 1997

We had developed a prototype Linear Pulse Motor(LPM) for the linear motion actuator. In this paper, it is mentioned a new dynamic equations which is considered the nonlinearity of the thrust force of LPM. And a measuring method of ripples in the thrust forces is proposed and the ripples were measured in the laboratory. In the experimental results, it is shown the validity of the proposed measuring method for catching of the ripple values and waveforms in the thrust force.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.116-118
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• 2007

In this paper, the notch of teeth, the shape changing and skew of permanent magnet are used to reduce the detent force. And addition, overhang of permanent magnet is applied to increase thrust because thrust is decreased by skew. As the results, detent force is decrease greatly about 98(%). And, the ripple ratio of thrust is decreased from 11.34(%) to 0.25(%).

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.804-806
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• 2001

In this paper, by designing ratio width of the permanent magnet versus the stator coil, double excitation LDM with multi-separated winding which is possible to obtain the constant thrust force is proposed. Using Empulse, this paper has explained a various excitation mode to analyze the thrust force of multi-separated winding LDM. The simulation results show single-phase excitation mode have low thrust force ripple.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.73-80
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• 1998

Recently, we have developed a linear brushless DC motor(LBLDCM) with high speed and precise position control performance to apply it to the semiconductor assembly and inspection machinery. It is composed of double side alignment by two armature-stator pairs and each pair is consist of a moving armature with 8 poles by 3 phase coils and a stator with rare earth permanent magnet (Nd-Fe-B) arrays. Through the thrust force analysis on a simplified and whole model of the suggested LBLDCM by an Electromagnetic FEM solver, skew angle of magnet arrays to reduce the thrust force ripple and the winding conditions of the armature is designed. From experimental results, the user's requirements was satisfied and we confirmed distinctly that the repeatable accuracy less than a micron of the linear motion can be obtained at high speed by the developed LBLDCM. This is owing to directly drive the work without the gear train.