Enhancement of Force Control Performance of Macro-Micro System Based Polishing Robot With Gravity Compensation

2021 ◽  
Author(s):  
Shotaro Ogawa ◽  
Katsuki Koto ◽  
Takuhiro Tsukada ◽  
Yasuhiro Kakinuma
Keyword(s):  
Surface Quality ◽  
Force Control ◽  
Tool Path ◽  
Rotation Speed ◽  
Reaction Force ◽  
Gravity Compensation ◽  
Control Performance ◽  
Skilled Workers ◽  
Polishing Process ◽  
Serial Link

Abstract In a fine mold manufacturing process, the polishing process plays an important role in enhancing the surface quality and is performed manually by skilled workers. However, there are many problems such as decrease in skilled workers, health hazards due to scattering of abrasives, and difference in surface quality due to difference in the proficiency. Hence, there is a strong demand for automation of the polishing process at present. In this research, a robot polishing system that applies macro-micro mechanism is proposed. The functional polishing module of the end effector is developed and attached to the hand of the serial link robot. Tool path and posture are controlled in a serial link robot as a macro mechanism, and polishing force and tool rotation speed are controlled in the developed polishing module as micro mechanism. This mechanism ideally controls position, force, and rotation speed at the same time. An interlocking control system for position and force has already been constructed. In this paper, we constructed gravity compensation and evaluated the force control performance of the constructed system. Through the evaluation, the followability of the estimated reaction force to the command force and the validity of the actual force behavior measured by the force sensor were evaluated.

Tool Posture and Polishing Force Control on Unknown 3-Dimensional Curved Surface

2016 ◽  
Author(s):  
Yuta Oba ◽  
Yasuhiro Kakinuma
Keyword(s):  
Force Control ◽  
Control Method ◽  
Reaction Force ◽  
Curved Surface ◽  
Skilled Workers ◽  
Polishing Process ◽  
Automotive Manufacturing ◽  
3 Dimensional ◽  
Polishing Force ◽  
Tool Posture

In the painting process in automotive manufacturing, the repair polishing process is still done manually by a worker with a sufficient skilled technique. However, the number of skilled workers is decreasing with the aging. In addition, the polishing time and the surface quality after the repair polishing are dependent on the proficiency level of the worker. Thus, skill-independent automation technology for the repair polishing is required. In our past research, the serial-parallel mechanism polishing machine was developed for automating the polishing process. The developed machine can control the tool trajectory, tool posture and polishing force simultaneously. In addition, the polishing force is controlled without external sensors by the reaction force observer system. This study aims to develop a polishing automation method for unknown 3-dimensional curved surface by using the developed machine. First, the tool posture control method on unknown curved surface was proposed. Second, the normal force control method based on the posture information was proposed. By using these proposed methods simultaneously, the tool posture and polishing force were controlled in the normal direction on unknown 3-dimesional curved surface. From the experimental results, the validity of the proposed method was verified.

Reaction Force Control of a Parallel Biwheel Vehicle Driven with a Stepping Motor

1999 ◽  
Vol 11 (5) ◽  
pp. 356-361 ◽  
Author(s):  
Nobuaki Hiraoka ◽  
◽  
Toshiro Noritsugu ◽  
Keyword(s):  
Force Control ◽  
Inverted Pendulum ◽  
Fuzzy Logic Controller ◽  
Sliding Mode ◽  
Reaction Force ◽  
Reference Signal ◽  
Wave Force ◽  
Open Loop ◽  
Control Performance ◽  
Force Magnitude

Reaction force control of a parallel biwheel vehicle (PBV) driven with two stepping motors in open loop mode is used for holding and transporting objects. The inverted pendulum type unstable PBV's attitude is regulated by a discrete time sliding mode controller. Reaction force is generated by contacting and leaning the PBV body toward objects and reaction force magnitude is controlled by a fuzzy logic controller whose nonlinear control achieves a quick, calm response. For a square wave force reference up to 1 N, the PBV quickly follows a reference signal without overshoot and maintains a steady reaction force. Control performance is discussed in detail aid compared to PI force control. The two PBVs cooperatively transport an object.

Flexible Polishing Machine with Dual Grinding Heads for Aeroengine Blade and Blisk

2011 ◽  
Vol 317-319 ◽  
pp. 2454-2460 ◽  
Author(s):  
Ji Hao Duan ◽  
Yao Yao Shi ◽  
Xiao Jun Lin ◽  
Ting Dong
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Control Method ◽  
Milling Process ◽  
Free Form ◽  
Skilled Workers ◽  
Polishing Process ◽  
Automatic Polishing ◽  
Polishing Machine ◽  
Polishing Tool

The blade and blisk manufacturing includes polishing process when the surface roughness and size requirement of profile are disqualified after milling process. This polishing process is mainly carried out manually by skilled workers or NC machines. However, the existing polishing technology always leads to surface quality instability and inconsistency because of the complex free-form surface of blade and blisk. Therefore, in this paper, based on the research of polishing requirements and methods of blade and blisk, an automatic 6-axis polishing machine was proposed in order to enhance surface quality. And then, a polishing mechanism was designed using flexible technique to make the polishing tool accommodate surface waviness which was produced in milling process. In addition, the working principle and control method of flexible polishing mechanism were studied. Finally, the polishing test results of blade and blisk showed that the profile error was about 0.06mm and the surface roughness was less than Ra0.4 after automatic polishing. Compared with the manual polishing process, the automatic polishing technology not only increased the polishing efficiency and quality stability, but also reduced labor intensity largely.

scholarly journals Study of ultrasonic vibration–assisted thread turning of Inconel 718 superalloy

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988377
Author(s):  
Yu He ◽  
Zhongming Zhou ◽  
Ping Zou ◽  
Xiaogang Gao ◽  
Kornel F Ehmann
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Inconel 718 ◽  
Gas Turbines ◽  
Tool Path ◽  
Machining Parameters ◽  
Thread Cutting ◽  
Workpiece Surface ◽  
Inconel 718 Superalloy ◽  
The Relationship

With excellent properties, high-temperature superalloys have become the main application materials for aircraft engines, gas turbines, and many other devices. However, superalloys are typically difficult to machine, especially for the thread cutting. In this article, an ultrasonic vibration–assisted turning system is proposed for thread cutting operations in superalloys. A theoretical analysis of ultrasonic vibration–assisted thread cutting is carried out. An ultrasonic vibration–assisted system was integrated into a standard lathe to demonstrate thread turning in Inconel 718 superalloy. The influence of ultrasonic vibration–assisted machining on workpiece surface quality, chip shape, and tool wear was analyzed. The relationship between machining parameters and ultrasonic vibration–assisted processing performance was also explored. By analyzing the motion relationship between tool path and workpiece surface, the reasons for improved workpiece surface quality by ultrasonic vibration–assisted machining were explained.

scholarly journals Surface Quality Improvement by Using a Novel Driving System Design in Single-Side Planetary Abrasive Lapping

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1691 ◽  
Author(s):  
Zhenzhen Chen ◽  
Donghui Wen ◽  
Jianfei Lu ◽  
Jie Yang ◽  
Huan Qi
Keyword(s):  
System Design ◽  
Surface Quality ◽  
Material Removal ◽  
Rotation Speed ◽  
Target Surface ◽  
Speed Ratio ◽  
The Novel ◽  
Particle Trajectories ◽  
Driving System ◽  
Single Side

For the traditional single-side planetary abrasive lapping process particle trajectories passing over the target surface are found to be periodically superposed due to the rational rotation speed ratio of the lapping plate to workpiece that could affect the material removal uniformity and hence its surface quality. This paper reports on a novel driving system design with combination of the tapered roller and contact roller to realize the irrational rotation speed ratio of the lapping plate to workpiece in the single-side planetary abrasive lapping process for the improvement of surface quality. Both of the numerical and experimental investigations have been conducted to evaluate the abrasive lapping performance of the novel driving system. It has been found from the numerical simulation that particle trajectories would theoretically cover the whole target surface if the lapping time is long enough due to their non-periodic characteristics, which can guarantee the uniformity of material removal from the surface of workpiece with relatively high surface quality. The encouraging experimental results underline the potential of the novel driving system design in the application of the single-side planetary abrasive lapping for the improvement of the surface quality in terms of surface roughness and material removal uniformity.

scholarly journals Study on Flexible Polishing Force and Polishing Temperature of Flap Disc

2021 ◽  
Author(s):  
De Liu ◽  
Xiaoming Pan ◽  
Zhiyang Gu ◽  
Hui Qiu
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Great Influence ◽  
Contact Length ◽  
Polished Surface ◽  
Polishing Process ◽  
Influence Of Process Parameters ◽  
Polishing Force ◽  
Working Principle ◽  
Cutting Model

Abstract Polishing determines the final surface quality of the aero engine, which have great influence on its working performance and working life. By analyzing the structure and working principle of the flexible self-adaptive polishing platform of the blisk, the abrasive cutting model of the flap disc is established. The theoretical calculation of the effect of elastic deformation during the polishing process on the contact length of flap disc and blisk. The model of polishing force, polishing heat and temperature field during the polishing process of the flap disc are established and analyzed. Single factor method is used to analyze the influence of process parameters on polishing force, polishing temperature, roughness and specific polishing energy. Finally, the polishing test shows that the optimized process parameters improve the polished surface quality and meet the requirements of the blade polishing process.

Experimental Investigation of Strengthening and Polishing Aeroengine Blades

2011 ◽  
Vol 101-102 ◽  
pp. 909-912
Author(s):  
Guo Ying Zeng ◽  
Deng Feng Zhao
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Fatigue Strength ◽  
Surface Quality ◽  
Three Dimensional ◽  
Experimental Results ◽  
Technological Parameters ◽  
Polishing Process ◽  
Optimum Parameters ◽  
The Media

The three-dimensional vibratory strengthening and polishing technology was used to strengthen and polish aeroengine blades with complicated surfaces. At first, the principle of the strengthening and polishing process was introduced, which combined strengthening process with polishing process. Then, the technological parameters influenced on the surface quality were investigated. The principal variables were the media hardness, the frequency and amplitude of the vibration, and duration of the vibratory strengthening and polishing. The optimum parameters were obtained. Experimental results revealed that, after strengthening and polishing, the surface roughness of aeroengine blades was reduced from Ra0.35-0.5μm to Ra0.1-0.12μm, and fatigue strength was increased by approximately 50%.

Development of a Pipe Positioning System Using a 5-DOF Suspension Mechanism

1999 ◽  
Author(s):  
Masaki Hayatsu ◽  
Shizuo Imaoka ◽  
Yasutaka Tagawa
Keyword(s):  
Control System ◽  
Disturbance Observer ◽  
Jacobian Matrix ◽  
Nonlinear Function ◽  
Center Of Gravity ◽  
Positioning System ◽  
Control Performance ◽  
Skilled Workers ◽  
Construction Sites ◽  
Plant Construction

Abstract Decreasing the number of skilled workers and utilization of automated machines is becoming a general trend at plant construction sites. For this reason, an automated pipe positioning system using a 5-DOF suspension mechanism has been developed as an important automated tool for power plant construction sites. This device is expected to be used for not only assisting less skilled operators, but also making operations more efficient at plant construction sites. This paper mainly focuses on the control system design and the control performance of the proposed positioning system. The controller is designed based on the disturbance observer concept. The pipe positioning system has a 5-DOF suspension mechanism which consists of five stepping motors and chains. A relationship between the actuator space (chain length) and the task space (position and attitude of the pipe center of gravity) is expressed using the Jacobian matrix, and each element of this Jacobian matrix is generally a nonlinear function in space. Therefore the plant in this system is nonlinear. In this study, a disturbance observer concept is used to remove this nonlinearlity, then a conventional linear feedback control low is applied to the control system. The control performance is verified through experiments using a pipe with a diameter of 0.3m. In the experiments, trajectories of the pipe center of gravity with the Jacobian nonlinearly compensation is compared to the trajectories without Jacobian compensation case, and the effectiveness of this pipe positioning system is shown.

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