A Free Form Robotic Grinding System: A Mathematical Model and an Actual System

Author(s):  
Shuihua Wu ◽  
Kazem Kazerounian ◽  
Zhongxue Gan ◽  
Yunquan Sun

This paper presents a robotic grinding system for work pieces with free-form geometries. A mathematical model representing the kinematics and dynamics of the system is built in the first part of the paper. Offline programming, calibration and a novel method for robotic error compensation are utilized to accurately generate the robotic grinding path. Models of the robot, the grinder and the grinding process are integrated to obtain the dynamics of the system. In the second part of the paper, an actual system is presented, with experiments done to verify the kinematic accuracy of the system. A controller based on the target tracking theory is designed to extend the system’s capability of material removal control, the effectiveness of which is shown by the simulation results. In the future, the target-tracking control strategy will be integrated with the actual system to develop a robotic grinding system capable of material removal control for free-form work pieces.

2011 ◽  
Vol 121-126 ◽  
pp. 2030-2034
Author(s):  
Dong Zhang ◽  
Chao Yun ◽  
Ling Zhang

The precision is impacted when the robotic grinding path is discontinuous and the gripper needs to be replaced during manufacturing. In order to solve this problem, a new type PPPRRR grinding robot was proposed. The mathematical model for the robotic grinding paths was set up. The factors including the pose of the workpiece respect to the end joint and the position of contact wheel respect to the robot base frame {O}were analyzed to influence the grinding ability of the system. Base on the Monte Carlo method the posture and position factors above had been optimized, and the grinding ability of the system was increased. The optimization methods were proved right and workable by grinding golf head experiment.


Author(s):  
Jan Eggert ◽  
Bernd Ku¨nne

The determination of the overall condition of an intralogistic system is one of the significant requirements of an effective planning of maintenance activities. Conventional maintenance concepts like time-based or event-based concepts already reach their limitations. By the application of condition-based maintenance concepts the single activities take place when the reserve of abrasion of a component is nearly optimally used. The application of the smart drive concept helps to determine the condition of the system while data of stationary and mobile sensor units are gathered and evaluated. Another aspect helps to delay potential breakdowns by the adaption of certain system parameters depending on the actual system load. In that way the individual load on some components can be reduced which makes it possible to schedule an appropriate maintenance activity before the breakdown occurs. Hence the availability can be enhanced since the probability of breakdowns and unplanned maintenance activities can be reduced. To adapt system parameters based on the actual load of an intralogistic system a mathematical model is needed which describes the system behavior to a certain extent. Based on the method of DoE (Design of Experiments) such a model can be established. In the first place screening designs are necessary to determine significant factors and factor interactions. Subsequently more detailed regression experiments have to be performed to derive the mathematical model. The first step of this process (screening experiments) has been performed and will be discussed at one example in this paper while the second step which will be performed in future work (regression experiments) will be introduced and prepared. It will also be explained how the derived model will be used in a technical context at a roller conveyor as an example of an intralogistic system.


Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4699
Author(s):  
Minming Gu ◽  
Yajie Wei ◽  
Haipeng Pan ◽  
Yujia Ying

This paper presents a new algorithm based on model reference Kalman torque prediction algorithm combined with the sliding root mean square (SRMS). It is necessary to improve the accuracy and reliability of the pinch detection for avoiding collision with the height adjustable desk and accidents on users. Motors need to regulate their position and speed during the operation using different voltage by PWM (Pulse Width Modulation) to meet the requirement of position synchronization. It causes much noise and coupling information in the current sampling signal. Firstly, to analyze the working principle of an electric height adjustable desk control system, a system model is established with consideration of the DC (Direct Current) motor characteristics and the coupling of the system. Secondly, to precisely identify the load situation, a new model reference Kalman perdition method is proposed. The load torque signal is selected as a pinch state variable of the filter by comparing the current signal. Thirdly, to meet the need of the different loads of the electric table, the sliding root means square (SRMS) of the torque is proposed to be the criterion for threshold detection. Finally, to verify the effectiveness of the algorithm, the experiments are carried out in the actual system. Experimental results show that the algorithm proposed in this paper can detect the pinched state accurately under different load conditions.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Shiqiang Wang ◽  
Jianchun Xing ◽  
Ziyan Jiang ◽  
Juelong Li

A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC) system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.


2015 ◽  
Vol 73 (6) ◽  
Author(s):  
Amir A. Bature ◽  
Salinda Buyamin ◽  
Mohamad N. Ahmad ◽  
Mustapha Muhammad ◽  
Auwalu A. Muhammad

In order to predict and analyse the behaviour of a real system, a simulated model is needed. The more accurate the model the better the response is when dealing with the real plant. This paper presents a model predictive position control of a Two Wheeled Inverted Pendulum robot. The model was developed by system identification using a grey box technique. Simulation results show superior performance of the gains computed using the grey box model as compared to common linearized mathematical model. 


2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
X K Zhang ◽  
G Q Zhang

In order to solve the problem that backstepping method cannot effectively guarantee the robust performance of the closed-loop system, a novel method of determining parameter is developed in this note. Based on the ship manoeuvring empirical knowledge and the closed-loop shaping theory, the derived parameters belong to a reduced robust group in the original stabilizing set. The uniformly asymptotic stability is achieved theoretically. The training vessel “Yulong” and the tanker “Daqing232” are selected as the plants in the simulation experiment. And the simulation results are presented to demonstrate the effectiveness of the proposed algorithm.


Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur Graziano ◽  
Hitomi Yamaguchi

Magnetic field–assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the workpiece. Relative motion between the brush and the workpiece causes microcutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces, surface roughness, and material removal rate was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness improved. Surface roughness values of 2–3 nm were achieved.


2014 ◽  
Vol 672-674 ◽  
pp. 1931-1934
Author(s):  
Yu Bing Dong ◽  
Guang Liang Cheng ◽  
Ming Jing Li

Occlusion is a difficult problem to be solved in the process of target tracking. In order to solve the problem of occlusion, a new tracking method combined with trajectory prediction and multi-block matching is presented and studied,and a mathematical model of trajectory prediction of moving target is established in polar coordinates and verified through some experiments. The experimental results show that the new tracking method can be better to trace and forecast the moving target under occlusion.


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