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Energy-efficient control of a screw-drive pipe robot with consideration of actuator's characteristics.

Li P, Ma S, Lyu C, Jiang X, Liu Y - Robotics Biomim (2016)

Bottom Line: Nevertheless, the energy is limited for the whole inspection task and cannot keep the inspection time too long.We also propose a velocity selection strategy that includes the actual velocity capacity of the motor, according to the velocity ratio [Formula: see text], to keep the robot working in safe region and decrease the energy dissipation.This selection strategy considers three situations of the velocity ratio [Formula: see text] and has a wide range of application.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering and Automation, Harbin Institute of Technology Shenzhen Graduate School, ShenZhen, 518055 China ; Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong China.

ABSTRACT

Pipe robots can perform inspection tasks to alleviate the damage caused by the pipe problems. Usually, the pipe robots carry batteries or use a power cable draining power from a vehicle that has many equipments for exploration. Nevertheless, the energy is limited for the whole inspection task and cannot keep the inspection time too long. In this paper, we use the total input energy as the cost function and a more accurate DC motor model to generate an optimal energy-efficient velocity control for a screw-drive pipe robot to make use of the limited energy in field environment. We also propose a velocity selection strategy that includes the actual velocity capacity of the motor, according to the velocity ratio [Formula: see text], to keep the robot working in safe region and decrease the energy dissipation. This selection strategy considers three situations of the velocity ratio [Formula: see text] and has a wide range of application. Simulations are conducted to compare the proposed method with the sinusoidal control and loss minimization control (minimization of copper losses of the motor), and results are discussed in this paper.

No MeSH data available.


Related in: MedlinePlus

Optimal velocity changes under various of a
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Fig7: Optimal velocity changes under various of a

Mentions: Trzynadlowski had discussed the optimal velocity by plotting a figure [12]. We will find the extremum of the velocity analytically. When , by using the infinite series expansion , (35) yields36\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\begin{aligned} \mathop {\lim }\limits _{a \rightarrow 0} {\omega _{2,\mathrm{m}}} = \frac{{6{\theta _{\mathrm{f}}}}}{{{t_{\mathrm{f}}}}}\left( {{\tau _1} - \tau _1^2} \right) \end{aligned}$$\end{document}lima→0ω2,m=6θftfτ1-τ12and when , (35) yields37\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\begin{aligned} \mathop {\lim }\limits _{a \rightarrow + \infty } {\omega _{2,\mathrm{m}}} = \frac{{S_{\mathrm{f}}}{i_{\mathrm{total}}}}{\gamma {t_{\mathrm{f}}}} \end{aligned}$$\end{document}lima→+∞ω2,m=Sfitotalγtf(36) and (37) can be explained as two extreme conditions for a certain system whose mechanical time constant has been decided. Assume keeps constant, and the final time varies. When is too short with respect to , the velocity profile will approach (36), but if is too long with respect to , the velocity profile is getting close to (37). For better understanding, let be the reference velocity and be the reference time, and when varies, Fig. 7 is plotted as velocity per unit versus time per unit by using the parameters of Table 1.Fig. 7


Energy-efficient control of a screw-drive pipe robot with consideration of actuator's characteristics.

Li P, Ma S, Lyu C, Jiang X, Liu Y - Robotics Biomim (2016)

Optimal velocity changes under various of a
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940445&req=5

Fig7: Optimal velocity changes under various of a
Mentions: Trzynadlowski had discussed the optimal velocity by plotting a figure [12]. We will find the extremum of the velocity analytically. When , by using the infinite series expansion , (35) yields36\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\begin{aligned} \mathop {\lim }\limits _{a \rightarrow 0} {\omega _{2,\mathrm{m}}} = \frac{{6{\theta _{\mathrm{f}}}}}{{{t_{\mathrm{f}}}}}\left( {{\tau _1} - \tau _1^2} \right) \end{aligned}$$\end{document}lima→0ω2,m=6θftfτ1-τ12and when , (35) yields37\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\begin{aligned} \mathop {\lim }\limits _{a \rightarrow + \infty } {\omega _{2,\mathrm{m}}} = \frac{{S_{\mathrm{f}}}{i_{\mathrm{total}}}}{\gamma {t_{\mathrm{f}}}} \end{aligned}$$\end{document}lima→+∞ω2,m=Sfitotalγtf(36) and (37) can be explained as two extreme conditions for a certain system whose mechanical time constant has been decided. Assume keeps constant, and the final time varies. When is too short with respect to , the velocity profile will approach (36), but if is too long with respect to , the velocity profile is getting close to (37). For better understanding, let be the reference velocity and be the reference time, and when varies, Fig. 7 is plotted as velocity per unit versus time per unit by using the parameters of Table 1.Fig. 7

Bottom Line: Nevertheless, the energy is limited for the whole inspection task and cannot keep the inspection time too long.We also propose a velocity selection strategy that includes the actual velocity capacity of the motor, according to the velocity ratio [Formula: see text], to keep the robot working in safe region and decrease the energy dissipation.This selection strategy considers three situations of the velocity ratio [Formula: see text] and has a wide range of application.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical Engineering and Automation, Harbin Institute of Technology Shenzhen Graduate School, ShenZhen, 518055 China ; Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong China.

ABSTRACT

Pipe robots can perform inspection tasks to alleviate the damage caused by the pipe problems. Usually, the pipe robots carry batteries or use a power cable draining power from a vehicle that has many equipments for exploration. Nevertheless, the energy is limited for the whole inspection task and cannot keep the inspection time too long. In this paper, we use the total input energy as the cost function and a more accurate DC motor model to generate an optimal energy-efficient velocity control for a screw-drive pipe robot to make use of the limited energy in field environment. We also propose a velocity selection strategy that includes the actual velocity capacity of the motor, according to the velocity ratio [Formula: see text], to keep the robot working in safe region and decrease the energy dissipation. This selection strategy considers three situations of the velocity ratio [Formula: see text] and has a wide range of application. Simulations are conducted to compare the proposed method with the sinusoidal control and loss minimization control (minimization of copper losses of the motor), and results are discussed in this paper.

No MeSH data available.


Related in: MedlinePlus