Increasing the frequency variation at position p 1 to

  • No School
  • AA 1
  • 13

This preview shows page 5 - 9 out of 13 pages.

Increasing the frequency variation at position P 1 to position P 2 and P 3 in X direction shows an increase in stiffness . Figure 7: Waterfall frequency diagram for X direction in P 3 position The same situation existed for 50.5 Hz frequency, which P 1 position is similar to the frequency of the electric network. This frequency increases reaching 53 Hz for P 2 and 55Hz for P 3 .The same evolution is finder in the case of 130-230 Hz frequency range. This observation shows that the X direction (the axial direction), the stiffness presents an increase when the TCP (tool center point) of robot go through the different position P 1 ,P 2 and P 3 .
Image of page 5
6 ICASAAM 2011 7-10 September 2011 Bucharest Romania Figure 8: Waterfall frequency diagram for Y direction in P 1 position For the Y direction (Figure 1) frequencies decrease slightly as the robot arm goes away from the position P 1 , (figure 8). Frequencies show a similar behavior, where the fundamental frequency from 12 Hz for P 1 position decrease to 10 Hz in position P 2 (figure 9) and 8 Hz for P 3 position (figure 10). Figure 9: Waterfall frequency diagram for Y direction in P 2 position
Image of page 6
7 7-10 September 2011 Bucharest Romania ICASAAM 2011 Figure 10: Waterfall frequency diagram for Y direction in P 3 position Figure 11: Waterfall frequency diagram for Z direction in P 1 position Figure 12: Waterfall frequency diagram for Z direction in P 2 position
Image of page 7
8 ICASAAM 2011 7-10 September 2011 Bucharest Romania Figure 13: Waterfall frequency diagram for Z direction in P 3 position The self excited frequencies in the Z direction (figure 1) show the same trend as the Y direction. The robot arm rigidity decreases, from position P 1 (figure 11) in relation with P 2 position (figure 12) and the P 3 position (figure 13). After analyzing the self-excited frequencies measured from the impact test to see a sensible increase in stiffness in the X direction and a decrease in stiffness in the direction Y and Z. The variation of the low frequency is about 10% at position P 1 to position P 2 respectively P 3 in the three directions. The analysis of the static frequency aims to impact frequency location of the robot in different configurations and their variation according to different position on the robot to perform. Thus obtain an overview of the self-excited frequency, where there is slight increase frequency in the X direction and a very small decrease of frequency in the Y and Z direction at P 1 position from P 2 and P 3 position. 4 Vibrations analysis during the spindle rotation Frequency analysis is performed in the dynamic case for the rotation speed of 12,032 rpm which can be identified both LFR and HFR frequency range, figure 12 in the P 1 position. The choice of tool speed is considering cutting parameters for testing and also the comparative material will be made between the behavior of the robot during the cutting process and outside the cutting process. The range of the high frequency represents the excitation of the component elements of the robot arm, representing one of the prospects of this research [10], [11]. By the spectrum analysis synchronized with rotational speed can identify
Image of page 8
Image of page 9

You've reached the end of your free preview.

Want to read all 13 pages?

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors