Analysis of Machining Disturbance and Development of a Support System for the Finishing Process

2009 ◽  
Author(s):  
Daiki Sakito ◽  
Yasushi Yasuda ◽  
Tsuginobu Osada ◽  
Ken’ichi Yano
Keyword(s):  
Contact Force ◽  
Support System ◽  
Control Method ◽  
Force Sensor ◽  
Tangential Direction ◽  
Friction Torque ◽  
Normal Direction ◽  
Haptic Device ◽  
Sensor Output ◽  
Finishing Process

In this paper we address the development of a finish machining support system that can operate without machining mistakes for the limited production of diversified products. The machining is supported by a haptic device. One challenge is that it is necessary to separate the force sensor output that exists in the operation force from the machining influence force. We propose a control method to remove the influence of the rotation tool disturbance force from the operation force by using adaptive modeling, which estimates the force of rotation tool friction torque in the tangential direction of the machining side from the contact force in the normal direction of the machining side. The effectiveness of this research is shown by a machining experiment.

Automated Robotic Deburring of Parts Using Compliance Control

1991 ◽  
Vol 113 (1) ◽  
pp. 60-66 ◽  
Author(s):  
M. G. Her ◽  
H. Kazerooni
Keyword(s):  
Cutting Forces ◽  
Control Method ◽  
Metal Removal ◽  
Roller Bearing ◽  
Force Sensor ◽  
Normal Direction ◽  
Contact Forces ◽  
Normal Vector ◽  
Two Dimensional ◽  
Removal Process

This work presents a method for robotic deburring of two-dimensional planar parts with unknown geometry. Robotic deburring requires “compliancy” and “stiffness” in the robot in the directions tangent and normal to the part, respectively. Compliancy in the tangential direction allows robotic accommodation of tangential cutting forces, while stiffness in the normal direction impedes a robotic response to normal cutting forces. But, to track the part contour, the robot requires compliancy in the normal direction. These conflicting requirements are addressed in this article as two problems: control of the metal removal process and tracking of the part contour. In general, these two problems are coupled; however, here they are separated into a hardware problem and a control problem. A tracking mechanism has been designed and built which incorporates a roller bearing mounted on a force sensor at the robot endpoint. This force sensor is located directly below the cutter and measures the contact forces which are the input to the tracking controller. These contact forces are used not only to calculate the normal vector to the part surface, but also to generate compliancy in the robot. However, the deburring algorithm uses another set of forces (cutting forces generated by the cutter) to produce a stable metal removal process. This deburring control method guarantees compliancy and stiffness in the robot in response to the tangential and normal cutting forces, respectively. Experimental results are given to show the effectiveness of this method for deburring of two-dimensional parts with unknown geometry.

Realization of Finishing Cuts Under Changing Machining Conditions by Machining Support Robots

2010 ◽  
Author(s):  
Tsuginobu Osada ◽  
Ken’ichi Yano ◽  
Mustapha S. Fofana
Keyword(s):  
Control System ◽  
Support System ◽  
Control Method ◽  
Haptic Device ◽  
Feed Speed ◽  
Bilateral Control ◽  
Precise Control ◽  
Finish Machining ◽  
Machining Conditions ◽  
Finishing Processes

Finishing processes such as deburring are performed on a wide variety of products in various quantities by workers on a piece-by-piece basis. Accordingly, the accuracy of the product depends on the worker’s skill. The aim of this research is to develop a finish machining support system. The machining is supported by using a haptic device and controlled by a bilateral control system. Here, we propose a control method based on a machining model made up of several components, including tool speed, feed speed of the tool and others, in order to control the robots under conditions in which it is possible to achieve highly accurate machining surfaces. The motion of a slave robot that requires precise control is controlled automatically, and the worker is given the force calculated by this control method. The effectiveness of this system is shown in a machining experiment.

SENSOR PVDF DENGAN POLARISASI PERMUKAAN SEBAGAI PENDETEKSI GAYA POTONG PADA MESIN GURDI

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Aditya Nugraha ◽  
Masri Bin Ardin
Keyword(s):  
Cutting Force ◽  
Output Signal ◽  
Axial Loading ◽  
Force Sensor ◽  
Maximum Deviation ◽  
Drilling Machine ◽  
Sensor Output ◽  
Sensor Surface ◽  
Surface Polarization ◽  
Tangential Directions

PVDF sensor is a sensor that is often used to measure force, strain, vibration and heat. In this study, PVDF sensors with surface polarization are used to detect cutting forces on the machine. The PVDF sensor that has been polarized on the surface is placed in the chuck part of the engine. Measuring instrumen for testing and calibrating PVDF sensors is oscilloscope with increased loading and reduced axial and tangential directions. After the calibration process, the PVDF sensor was used to measure cutting force on drilling machine, and then the results were compared with the PCB piezotronics force sensor. The PVDF sensor output signal is measured and studied for its voltage using an oscilloscope, where the output signal is compared to the weight given to the PVDF sensor. From the results of these tests indicate that the maximum deviation in axial loading is 0.32V while the tangential loading is 0.31VKeywords. PVDF sensor, Surface polarization, Drilling machine, Cutting force

scholarly journals Development of a Wearable Mouth Guard Device for Monitoring Teeth Clenching during Exercise

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1503
Author(s):  
Rio Kinjo ◽  
Takahiro Wada ◽  
Hiroshi Churei ◽  
Takehiro Ohmi ◽  
Kairi Hayashi ◽  
...  
Keyword(s):  
Force Sensor ◽  
Tolerance Test ◽  
Sensor Output ◽  
Sports Performance ◽  
Teeth Grinding ◽  
Exercise Tolerance Test ◽  
Sensor Position ◽  
Video Motion Analysis ◽  
Teeth Clenching ◽  
The Relationship

Teeth clenching during exercise is important for sports performance and health. Recently, several mouth guard (MG)-type wearable devices for exercise were studied because they do not disrupt the exercise. In this study, we developed a wearable MG device with force sensors on both sides of the maxillary first molars to monitor teeth clenching. The force sensor output increased linearly up to 70 N. In four simple occlusion tests, the trends exhibited by the outputs of the MG sensor were consistent with those of an electromyogram (EMG), and the MG device featured sufficient temporal resolution to measure the timing of teeth clenching. When the jaw moved, the MG sensor outputs depended on the sensor position. The MG sensor output from the teeth-grinding test agreed with the video-motion analysis results. It was comparatively difficult to use the EMG because it contained a significant noise level. Finally, the usefulness of the MG sensor was confirmed through an exercise tolerance test. This study indicated that the developed wearable MG device is useful for monitoring clenching timing and duration, and the degree of clenching during exercise, which can contribute to explaining the relationship between teeth clenching and sports performance.

Design and control of 2-DoF joystick using MR-fluid rotary actuator

2021 ◽  
pp. 1045389X2110639
Author(s):  
Bao Tri Diep ◽  
Quoc Hung Nguyen ◽  
Thanh Danh Le
Keyword(s):  
Pid Controller ◽  
Force Feedback ◽  
Control Method ◽  
Open Loop ◽  
Friction Torque ◽  
Feedback Controls ◽  
Loop Control ◽  
Fuzzy Logic Algorithm ◽  
Experimental Apparatus ◽  
Close Loop Control

The purpose of this paper is to design a control algorithm for a 2-DoF rotary joystick model. Firstly, the structure of the joystick, which composes of two magneto-rheological fluid actuators (shorten MRFA) with optimal configuration coupled perpendicularly by the gimbal mechanism to generate the friction torque for each independent rotary movement, is introduced. The control strategy of the designed joystick is then suggested. Really, because of two independent rotary movements, it is necessary to design two corresponding controllers. Due to hysteresis and nonlinear dynamic characteristics of the MRFA, controllers based an accurate dynamic model are difficult to realize. Hence, to release this issue, the proposed controller (named self-turning fuzzy controllers-STFC) will be built through the fuzzy logic algorithm in which the parameters of controllers are learned and trained online by Levenberg-Marquardt training algorithm. Finally, an experimental apparatus will be constructed to assess the effectiveness of the force feedback controls. Herein, three experimental cases are performed to compare the control performance of open-loop and close-loop control method, where the former is done through relationship between the force at the knob and the current supplied to coil while the latter is realized based on the proposed controller and PID controller. The experimental results provide strongly the ability of the proposed controller, meaning that the STFC is robust and tracks well the desirable force with high accuracy compared with both the PID controller and the open-loop control method.

An Extension of CEB Elastic-Plastic Contact Model

2007 ◽  
Author(s):  
A. Sepehri ◽  
K. Farhang
Keyword(s):  
Contact Force ◽  
Tangential Force ◽  
Three Dimensional ◽  
Tangential Direction ◽  
Asperity Contact ◽  
Force Component ◽  
Normal Contact ◽  
Elastic Plastic ◽  
Force Components ◽  
Plastic Parts

Three dimensional elastic-plastic contact of two nominally flat rough surfaces is by developing the equations governing the shoulder-shoulder contact of asperities based on the Chang, Etsion and Bogy (CEB) model of contact in which volume conservation is assumed in the plastic flow regime. Shoulder-shoulder asperity contact yields a slanted contact force consisting of both tangential (parallel to mean plane) and normal components. Each force component comprises elastic and elastic-plastic parts. Statistical summation of normal force components leads to the derivation of the normal contact force for the elastic-plastic contact akin to the CEB model. Half-plane tangential force due to elastic-plastic contact is derived through the statistical summation of tangential force component along an arbitrary tangential direction.

scholarly journals An Improved Path-Generating Regulator for Two-Wheeled Robots to Track the Circle/Arc Passage

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Jun Dai ◽  
Naohiko Hanajima ◽  
Toshiharu Kazama ◽  
Akihiko Takashima
Keyword(s):  
Control Method ◽  
Convergence Property ◽  
Tangential Direction ◽  
Navigation Problem ◽  
Wheeled Robots ◽  
Robot Trajectory ◽  
Look Ahead ◽  
Straight Line ◽  
The Family ◽  
Straight Lines

The improved path-generating regulator (PGR) is proposed to path track the circle/arc passage for two-wheeled robots. The PGR, which is a control method for robots so as to orient its heading toward the tangential direction of one of the curves belonging to the family of path functions, is applied to navigation problem originally. Driving environments for robots are usually roads, streets, paths, passages, and ridges. These tracks can be seen as they consist of straight lines and arcs. In the case of small interval, arc can be regarded as straight line approximately; therefore we extended the PGR to drive the robot move along circle/arc passage based on the theory that PGR to track the straight passage. In addition, the adjustable look-ahead method is proposed to improve the robot trajectory convergence property to the target circle/arc. The effectiveness is proved through MATLAB simulations on both the comparisons with the PGR and the improved PGR with adjustable look-ahead method. The results of numerical simulations show that the adjustable look-ahead method has better convergence property and stronger capacity of resisting disturbance.

scholarly journals A Micro-Force Sensor with Beam-Membrane Structure for Measurement of Friction Torque in Rotating MEMS Machines

Micromachines ◽  
2017 ◽  
Vol 8 (10) ◽  
pp. 304
Author(s):  
Huan Liu ◽  
Zhongliang Yu ◽  
Yan Liu ◽  
Xudong Fang
Keyword(s):  
Membrane Structure ◽  
Force Sensor ◽  
Friction Torque ◽  
Micro Force Sensor

Tension Control Strategy in Plastic Film Printing Process

2013 ◽  
Vol 655-657 ◽  
pp. 1321-1325
Author(s):  
Peng Sun ◽  
Peng Cao
Keyword(s):  
Control Method ◽  
Friction Torque ◽  
Tension Control ◽  
Rotational Inertia ◽  
Plastic Film ◽  
Diameter Measurement ◽  
Dynamic Tension ◽  
Drive Control ◽  
Coil Diameter ◽  
Constant Tension

The character of the tension control in the plastic-film printing was introduced, and the coiler drive control method was given. The indirect constant tension control method was analyzed, and the key parameters were given, also the method of coil diameter measurement with distance meter, the friction torque in different rotate speed was given by the friction torque test; the method of rotational inertia measurement which influence the dynamic tension was put forward.

scholarly journals Experimental Evaluation on Haptic Feedback Accuracy by Using Two Self-Made Haptic Devices and One Additional Interface in Robotic Teleoperation

Actuators ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Guan-Yang Liu ◽  
Yi Wang ◽  
Chao Huang ◽  
Chen Guan ◽  
Dong-Tao Ma ◽  
...  
Keyword(s):  
Experimental Evaluation ◽  
Haptic Feedback ◽  
Force Sensor ◽  
Interaction Force ◽  
Haptic Device ◽  
Human Hand ◽  
Haptic Devices ◽  
Input Noise ◽  
Output Force ◽  
Robotic Teleoperation

The goal of haptic feedback in robotic teleoperation is to enable users to accurately feel the interaction force measured at the slave side and precisely understand what is happening in the slave environment. The accuracy of the feedback force describing the error between the actual feedback force felt by a user at the master side and the measured interaction force at the slave side is the key performance indicator for haptic display in robotic teleoperation. In this paper, we evaluate the haptic feedback accuracy in robotic teleoperation via experimental method. A special interface iHandle and two haptic devices, iGrasp-T and iGrasp-R, designed for robotic teleoperation are developed for experimental evaluation. The device iHandle integrates a high-performance force sensor and a micro attitude and heading reference system which can be used to identify human upper limb motor abilities, such as posture maintenance and force application. When a user is asked to grasp the iHandle and maintain a fixed position and posture, the fluctuation value of hand posture is measured to be between 2 and 8 degrees. Based on the experimental results, human hand tremble as input noise sensed by the haptic device is found to be a major reason that results in the noise of output force from haptic device if the spring-damping model is used to render feedback force. Therefore, haptic rendering algorithms should be independent of hand motion information to avoid input noise from human hand to the haptic control loop in teleoperation. Moreover, the iHandle can be fixed at the end effector of haptic devices; iGrasp-T or iGrasp-R, to measure the output force/torque from iGrasp-T or iGrasp-Rand to the user. Experimental results show that the accuracy of the output force from haptic device iGrasp-T is approximately 0.92 N, and using the force sensor in the iHandle can compensate for the output force inaccuracy of device iGrasp-T to 0.1 N. Using a force sensor as the feedback link to form a closed-loop feedback force control system is an effective way to improve the accuracy of feedback force and guarantee high-fidelity of feedback forces at the master side in robotic teleoperation.

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