Ryuta Sato - Academia.edu (original) (raw)

Papers by Ryuta Sato

Research paper thumbnail of Motion Control Techniques of Rotary Table for 5-axis Machining Centers

Proceedings of International Conference on Leading Edge Manufacturing in 21st Century, 2007

Research paper thumbnail of Evaluation and Compensation of Dynamic Behavior of Rotary Axis by Motion Direction Changes in 5-Axis Controlled Machining Center

Seimitsu Kōgakkaishi, 2016

Research paper thumbnail of Development of Servo-clinometer Using Rotary Encoder and Precision Level

Proceedings of International Conference on Leading Edge Manufacturing in 21st Century, 2007

Research paper thumbnail of Applicability assessment and adaptation method of cutting conditions based on acceptable area to select cutting conditions for end-milling operation

Nihon kikai gakkai ronbunshu, 2020

Research paper thumbnail of Voxel Based End-milling Simulation Considering Elastic Deflection of Tool System

Seimitsu Kōgakkaishi, Jun 5, 2018

Research paper thumbnail of Automatic process planning system for end-milling operation considering CAM operator's intention

Nihon kikai gakkai ronbunshu, 2018

Research paper thumbnail of Machining state monitoring in end milling based on comparison of monitored and predicted cutting torques

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2019

Research paper thumbnail of E36 Development of Torque-follow Compensator Corresponding to Friction Force Change, and High-accuracy Compensation of Quadrant Glitches

The Proceedings of The Manufacturing & Machine Tool Conference, 2008

Research paper thumbnail of S142011 On-Machine Measurement Based on Copying Principle Using Laser Displacement Sensor

The Proceedings of Mechanical Engineering Congress, Japan, 2013

Research paper thumbnail of S141016 Generation of NC program corresponding to raw material shape to eliminate waste time for air-cut motion

The Proceedings of Mechanical Engineering Congress, Japan, 2012

Research paper thumbnail of 1408 Voxel Representation of Removal Volume to Enhance Autonomy of Digital Copy Milling System

The Proceedings of Conference of Kansai Branch, 2012

Research paper thumbnail of On-machine measurement and correction of machining error using laser displacement sensor

Nihon kikai gakkai ronbunshu, 2018

Research paper thumbnail of A Study on the Mathematical Model of Feed Drive Mechanism for Machine Tools

The Proceedings of The Manufacturing & Machine Tool Conference, 2002

Research paper thumbnail of G25 Study on evaluation methods of synchronous motion accuracy of five-axis machining centers

The Proceedings of Conference of Kyushu Branch, 2006

Research paper thumbnail of Motion Characteristics of High Performance Rotary Tables for CNC Machines

Volume 11: Mechanical Systems and Control, 2008

In this paper, the characteristics of two rotary tables driven by worm gear and roller gear cam a... more In this paper, the characteristics of two rotary tables driven by worm gear and roller gear cam are measured and compared. The positioning accuracy and repeatability as specified in ISO 230-2 are measured together with the rotational fluctuation, backlash, friction torque, frequency response of the systems and also the influence of unbalance mass on rotational motion. Two rotary encoders which were attached to motor and output axis were used for measurements. The motor, controller, and the rotary encoders were kept the same for both tables to ignore the effects of these units on results. Furthermore, the simulations were carried out by mathematical models which were proposed by two of the authors and the results were compared with measured results. From the simulation results, the torsional stiffness and friction torque were identified and also compared. The results show that the measured and simulated data have a good agreement and therefore it can be said that the identified param...

Research paper thumbnail of Finished Surface Simulation Method to Predicting the Effects of Machine Tool Motion Errors

International Journal of Automation Technology, 2014

This paper proposes a method of simulating the effects of the machining center motion errors onto... more This paper proposes a method of simulating the effects of the machining center motion errors onto the finished surface. The proposed simulation method consists of the servo delay models of feed drive systems, a geometrical error model of the machine tool, a machined shape simulator, and a renderer. In order to compare the simulated finished surfaces with the machined one, tests consisting of machining spheres are carried out using a ball-end mill. As result, it is proven that the proposed simulation method can adequately simulate the effects of motion errors on the finished surface. In addition, an investigation into the cause of blemishes is carried out. It is also confirmed that the proposed method can be an effective tool in the identification of the causes of blemishes on the surface.

Research paper thumbnail of Development of contact detection method between tool cutting edge and workpiece (Influence of contact state onto vibration characteristics and contact detection during milling operation)

Journal of Advanced Mechanical Design, Systems, and Manufacturing

The contact between a tool and workpiece during machining has a significant effect on the vibrati... more The contact between a tool and workpiece during machining has a significant effect on the vibration characteristics of machine tools. This study proposes a method for detecting contact between a tool and workpiece, and demonstrates applications of the detection. To detect the contact between the tool and workpiece, this study used the change in the contact electrical resistance in a metal-to-metal contact corresponding to the true contact area. The contact resistance between the tool and workpiece was connected in series with a buffer resistance, and the degree of separation was defined based on the change in the ratio of a voltage applied to the circuit under a constant current flow. Two types of applications were demonstrated in this study; one was an analysis of the influences of the contact state on the vibration characteristics, and the other was contact detection during milling operations. In the first demonstration, a contacting ratio was defined based on the contact time per unit time and degree of separation based on the tool-workpiece contact as detected during an excitation test, and the relationship between the contacting ratio and vibration characteristics was examined. It was confirmed that the natural frequency increases significantly when the contacting ratio exceeds 90%, and that the damping characteristics increase significantly when the contacting ratio is in the range of 0-10%. For the second demonstration, a milling test using a face mill with the same detection circuit confirmed that the system could detect contact during intermittent cutting and the changes in contact conditions associated with the occurrence of chattering vibration. It is expected that the developed method can be used to monitor machining conditions.

Research paper thumbnail of Investigation of the influence of NC controller and control mode by machining tests of blades on machining time

Research paper thumbnail of Influences of geometric and dynamic synchronous errors onto machined surface in 5-axis machining center

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2016

Unexpected glitches typically occur on the finished surface machined by the 5-axis machining cent... more Unexpected glitches typically occur on the finished surface machined by the 5-axis machining centers, because of geometric and dynamic synchronous errors of the machine. In this study, actual ball-nosed end milling tests of hemispheres and its finished surface simulations with different geometric errors and different position loop gain of feed drive systems were carried out, in order to clarify the influence of the geometric and dynamic synchronous errors onto machined surface. As the results, it is clarified that the influence of geometric errors onto the machined surface is depending on the relationships between the movement of the axes and the surface geometry. In addition, the dynamic synchronous error also influences the machined surface when the velocity of translational and rotary axes changed rapidly.

Research paper thumbnail of A practical method to monitor tool wear in end milling using a changing cutting force model that requires no additional sensors

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2021

In end milling, proper tool life management is crucially important for achieving highly accurate ... more In end milling, proper tool life management is crucially important for achieving highly accurate machining, avoiding tool failure, and optimizing production costs. In recent years, a number of tool condition monitoring (TCM) methods aimed at improving tool life management have been proposed. However, these methods have generally been impractical, and tool life still tends to be determined based on machining time or the quantity of the product produced. To address this shortcoming, a practical online TCM method is proposed. The proposed method is based on the idea that the frictional force acting on the flank face of a tool increases with increasing flank wear resulting from an increase in the contact surface area between the flank face and the machined surface. The implication is that tool wear can be indirectly monitored using the change in frictional force on the flank face, which can be determined by tracking the spindle motor torque obtained using a computerized numerical control (CNC) controller and a real time cutting force simulation. The influence of tool wear is not considered in the simulation model; rather, the frictional force is estimated from the difference between the average predicted cutting torque and the average monitored spindle motor torque. With the proposed method, no additional sensor is needed to monitor tool wear. Additionally, no parameter determination is necessary to perform the simulation because the parameters needed for the simulation are immediately determined at the beginning of the milling operation based on the monitored spindle motor torque. Thus, the TCM method proposed here offers a practical online alternative.

Research paper thumbnail of Motion Control Techniques of Rotary Table for 5-axis Machining Centers

Proceedings of International Conference on Leading Edge Manufacturing in 21st Century, 2007

Research paper thumbnail of Evaluation and Compensation of Dynamic Behavior of Rotary Axis by Motion Direction Changes in 5-Axis Controlled Machining Center

Seimitsu Kōgakkaishi, 2016

Research paper thumbnail of Development of Servo-clinometer Using Rotary Encoder and Precision Level

Proceedings of International Conference on Leading Edge Manufacturing in 21st Century, 2007

Research paper thumbnail of Applicability assessment and adaptation method of cutting conditions based on acceptable area to select cutting conditions for end-milling operation

Nihon kikai gakkai ronbunshu, 2020

Research paper thumbnail of Voxel Based End-milling Simulation Considering Elastic Deflection of Tool System

Seimitsu Kōgakkaishi, Jun 5, 2018

Research paper thumbnail of Automatic process planning system for end-milling operation considering CAM operator's intention

Nihon kikai gakkai ronbunshu, 2018

Research paper thumbnail of Machining state monitoring in end milling based on comparison of monitored and predicted cutting torques

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2019

Research paper thumbnail of E36 Development of Torque-follow Compensator Corresponding to Friction Force Change, and High-accuracy Compensation of Quadrant Glitches

The Proceedings of The Manufacturing & Machine Tool Conference, 2008

Research paper thumbnail of S142011 On-Machine Measurement Based on Copying Principle Using Laser Displacement Sensor

The Proceedings of Mechanical Engineering Congress, Japan, 2013

Research paper thumbnail of S141016 Generation of NC program corresponding to raw material shape to eliminate waste time for air-cut motion

The Proceedings of Mechanical Engineering Congress, Japan, 2012

Research paper thumbnail of 1408 Voxel Representation of Removal Volume to Enhance Autonomy of Digital Copy Milling System

The Proceedings of Conference of Kansai Branch, 2012

Research paper thumbnail of On-machine measurement and correction of machining error using laser displacement sensor

Nihon kikai gakkai ronbunshu, 2018

Research paper thumbnail of A Study on the Mathematical Model of Feed Drive Mechanism for Machine Tools

The Proceedings of The Manufacturing & Machine Tool Conference, 2002

Research paper thumbnail of G25 Study on evaluation methods of synchronous motion accuracy of five-axis machining centers

The Proceedings of Conference of Kyushu Branch, 2006

Research paper thumbnail of Motion Characteristics of High Performance Rotary Tables for CNC Machines

Volume 11: Mechanical Systems and Control, 2008

In this paper, the characteristics of two rotary tables driven by worm gear and roller gear cam a... more In this paper, the characteristics of two rotary tables driven by worm gear and roller gear cam are measured and compared. The positioning accuracy and repeatability as specified in ISO 230-2 are measured together with the rotational fluctuation, backlash, friction torque, frequency response of the systems and also the influence of unbalance mass on rotational motion. Two rotary encoders which were attached to motor and output axis were used for measurements. The motor, controller, and the rotary encoders were kept the same for both tables to ignore the effects of these units on results. Furthermore, the simulations were carried out by mathematical models which were proposed by two of the authors and the results were compared with measured results. From the simulation results, the torsional stiffness and friction torque were identified and also compared. The results show that the measured and simulated data have a good agreement and therefore it can be said that the identified param...

Research paper thumbnail of Finished Surface Simulation Method to Predicting the Effects of Machine Tool Motion Errors

International Journal of Automation Technology, 2014

This paper proposes a method of simulating the effects of the machining center motion errors onto... more This paper proposes a method of simulating the effects of the machining center motion errors onto the finished surface. The proposed simulation method consists of the servo delay models of feed drive systems, a geometrical error model of the machine tool, a machined shape simulator, and a renderer. In order to compare the simulated finished surfaces with the machined one, tests consisting of machining spheres are carried out using a ball-end mill. As result, it is proven that the proposed simulation method can adequately simulate the effects of motion errors on the finished surface. In addition, an investigation into the cause of blemishes is carried out. It is also confirmed that the proposed method can be an effective tool in the identification of the causes of blemishes on the surface.

Research paper thumbnail of Development of contact detection method between tool cutting edge and workpiece (Influence of contact state onto vibration characteristics and contact detection during milling operation)

Journal of Advanced Mechanical Design, Systems, and Manufacturing

The contact between a tool and workpiece during machining has a significant effect on the vibrati... more The contact between a tool and workpiece during machining has a significant effect on the vibration characteristics of machine tools. This study proposes a method for detecting contact between a tool and workpiece, and demonstrates applications of the detection. To detect the contact between the tool and workpiece, this study used the change in the contact electrical resistance in a metal-to-metal contact corresponding to the true contact area. The contact resistance between the tool and workpiece was connected in series with a buffer resistance, and the degree of separation was defined based on the change in the ratio of a voltage applied to the circuit under a constant current flow. Two types of applications were demonstrated in this study; one was an analysis of the influences of the contact state on the vibration characteristics, and the other was contact detection during milling operations. In the first demonstration, a contacting ratio was defined based on the contact time per unit time and degree of separation based on the tool-workpiece contact as detected during an excitation test, and the relationship between the contacting ratio and vibration characteristics was examined. It was confirmed that the natural frequency increases significantly when the contacting ratio exceeds 90%, and that the damping characteristics increase significantly when the contacting ratio is in the range of 0-10%. For the second demonstration, a milling test using a face mill with the same detection circuit confirmed that the system could detect contact during intermittent cutting and the changes in contact conditions associated with the occurrence of chattering vibration. It is expected that the developed method can be used to monitor machining conditions.

Research paper thumbnail of Investigation of the influence of NC controller and control mode by machining tests of blades on machining time

Research paper thumbnail of Influences of geometric and dynamic synchronous errors onto machined surface in 5-axis machining center

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2016

Unexpected glitches typically occur on the finished surface machined by the 5-axis machining cent... more Unexpected glitches typically occur on the finished surface machined by the 5-axis machining centers, because of geometric and dynamic synchronous errors of the machine. In this study, actual ball-nosed end milling tests of hemispheres and its finished surface simulations with different geometric errors and different position loop gain of feed drive systems were carried out, in order to clarify the influence of the geometric and dynamic synchronous errors onto machined surface. As the results, it is clarified that the influence of geometric errors onto the machined surface is depending on the relationships between the movement of the axes and the surface geometry. In addition, the dynamic synchronous error also influences the machined surface when the velocity of translational and rotary axes changed rapidly.

Research paper thumbnail of A practical method to monitor tool wear in end milling using a changing cutting force model that requires no additional sensors

Journal of Advanced Mechanical Design, Systems, and Manufacturing, 2021

In end milling, proper tool life management is crucially important for achieving highly accurate ... more In end milling, proper tool life management is crucially important for achieving highly accurate machining, avoiding tool failure, and optimizing production costs. In recent years, a number of tool condition monitoring (TCM) methods aimed at improving tool life management have been proposed. However, these methods have generally been impractical, and tool life still tends to be determined based on machining time or the quantity of the product produced. To address this shortcoming, a practical online TCM method is proposed. The proposed method is based on the idea that the frictional force acting on the flank face of a tool increases with increasing flank wear resulting from an increase in the contact surface area between the flank face and the machined surface. The implication is that tool wear can be indirectly monitored using the change in frictional force on the flank face, which can be determined by tracking the spindle motor torque obtained using a computerized numerical control (CNC) controller and a real time cutting force simulation. The influence of tool wear is not considered in the simulation model; rather, the frictional force is estimated from the difference between the average predicted cutting torque and the average monitored spindle motor torque. With the proposed method, no additional sensor is needed to monitor tool wear. Additionally, no parameter determination is necessary to perform the simulation because the parameters needed for the simulation are immediately determined at the beginning of the milling operation based on the monitored spindle motor torque. Thus, the TCM method proposed here offers a practical online alternative.