puma slides

[Ernest Child]

Three sirn-plifying assumptions were made for this analysis: puma slides the rigid bodyassumption;link 6 hasbeenassumed to besymmetric, that isI,% = Zyy; and only the mass moments of inertia are considered,that is I,,, Zyy and Z z z . The original output of EMDEG, includ-ing Coriolisand centrifugal terms, required 15,000 multiplicationsand 3,500 additions. This step might also have been performedwith the momentum theorem method used in [lzaguirre and Paul19851.In the second step of this procedure, the kinetic energy ma- The reduction of Equation (7) arises from the symmetry oftrix elements are simplified by combining inertia constants that the kineticenergymatrix.

The twowire direct measurement contributing to the calculation. The inertiasuspension method of measuring the rotational inertia requires dyadic and center of gravity parameters of link 3 were measuredknowledge of parameters that are easily measured: the mass with the wrist attached; the values reported for link3 alone have been obtained by subtracting the contribution of the wrist from 9 the total of link 3 plus wrist. puma fenty Tolerance values are reported with the values for link 3 plus wrist, as these are the original measure- ments. 6. T h e Measured PUMA 660 Parameters "9 The mass of links 2 through 6 of the PUMA arm are reported in Table4;the mass of link 1in not included becausethat link was Figure 1.

fenty by puma If one is carefulwhenreleasing the link, it Link 2 17.40is possible to start fundamentalmodeoscillationwithout visi- Link 3 4.80blyexcitingany of the other modes. The relationshipbetween Link 4* 0.82measured properties and rotational inertia is: Link 5* 0.34 Link 6* 0.09 * This method was suggested by Prof. David Powell. Link 3 wiCthomplete LVrist 6.04 Detached Wrist 2.24 * Values derived from external dimensions; f 2 5 % . The positions of the centers of gravity are reported in Table 5. The dimensions rz! ry and rz refer to the x, y and z coordinates 513of the center of gravity in the coordinate frame attached t o the Table 5 . puma thunder spectra Centers of Gravity.

(meters 3=0.003)link. Thecoordinateframesusedareassigned by a modifiedDenavit-Hartenbrrgmethod[Craig 85j. In thisvariant of theDenavit-Hartenbergmethod,frame i is attached to link i, and 0.006axis 2i lies along the axis of rotation of joint i. The coordinateframe attachments are shown inFigure 2; theyarelocated as Link 3 -0.070 0.014follows:Link 1: Z axisalong the axis of rotation, Z up; Y1 11 5 Link 3 -0.143 10.014 With Wrist Z2. Link 4* -0.019 Link 5* 0.032Link 2: Z axisalong the axis of rotation , Z awayfrom Link 6* Wrist 0 -0.064 the base; X-Y plane in the center of the link, with X toward link 3.Link 3: 23 11 22; X-Y plane is in the center of l i d 3; Y is away from the wrist.

Link 4: The origin is at the intersection of the axes of joints * Values derived from external dimensions; &25%. 4 5 and 6; 24 is along the axis of rotationand The effective torsional spring methodof inertia measurement was appliedateachjoint.Themotor and drive inertia, Imotor, direct.ed away from link 2; Y4 11 Z3 whenjoint were foundby subtractingtheinertialcontributiondue to the arm dynamics, known from direct measurements, from the total 4 is in the zero position. inert,ia measured.Theuncertainty in the total inertia measure- ment is somewhat higher at joint one becauseof the larger frictionLink 5: The origin coincides withthat of frame 4; Z5 is di- at puma football boots that joint.

It was necessary to add positive velocity feedback rected away from the base; Y5 is directed toward (damping factor -0.1) to causejoint one to oscillateforseveral link 2 when joint 5 is in the zero position. cycles.Link 6: Theorigincoincideswith that of frame 4; when joints 5 and 6 arein the zeropositionframe 6 is aligned with frame 4.Wrist : The dimensions are reported in frame 4. Table 6. DiagonalTerms of the Inertia Dyadics and Effective Motor Inertia.Figure 2. The PUMA 560 in the Zero Position with Attached * Iucrtia Diadic [img]http://www.simplypotterheads.com/images/lose/puma fenty-286dtd.jpg[/img] term derived from external dimenJions; *SO%. Coordinate Frames Shown.