In this study, an on-line forecasting compensatory control (FCC) strategy is successfully employed to improve the workpiece accuracy in taper machining by compensating the relative two-dimensional motion errors between the workpiece and the cutting tool. The indirect measurement set-up is developed to determine the motion errors, in both radial and longitudinal directions, of the spindle which positions the workpiece via a master taper. Also, the straightness motion errors of the x-y slide are determined to give the actual tool positions. The reference datum in these measurements, i.e. the master form error and the slide profile, can be determined under on-machine conditions and highly accurate precalibrated references are not required. Based on the autoregressive moving average (ARMA) technique, the two-dimensional motion errors are modelled and their future values forecasted and compensated by means of a piezoelectric actuator. The adequate model order and parameters are found by performing off-line simulations. The effectiveness of the FCC strategy is also evaluated by comparing the roundness results with and without compensation. Experimental cutting with FCC reveals that a maximum improvement of 68 per cent and an average improvement of 41 per cent can be achieved for workpiece roundness in this taper machining process.
WuS. M.Dynamic data systems: A new modeling approach. Trans. ASME, J. Engng for Industry, 1977, 99(3), 708–714.
2.
PanditS. M.WuS. M.Time Series and System Analysis with Applications, 1983 (John Wiley, New York).
3.
RaoS. B.WuS. M.Compensatory control of roundness error in cylindrical chuck grinding. Trans. ASME, J. Engng for Industry, 1982, 104, 385–391.
4.
KimK. H.EmanK. F.WuS. M.Development of a forecasting compensatory control system for cylindrical grinding. Trans. ASME, J. Engng for Industry, 1987, 109, 385–391.
5.
ParkC. W.EmanK. F.WuS. M.An in-process flatness error measurement and compensatory control system. Trans. ASME, J. Engng for Industry, 1988, 110, 263–270.
6.
KimK.Forecasting compensatory control of cylindricity in contour boring operations. PhD thesis, The University of Wisconsin at Madison, 1986.
7.
ChiuW. M.ChanK. W.Development of active error-compensation boring bar for precision machining. In Proceedings of the 1st Asia-Pacific and 2nd Japan—China International Conference on Progress of Cutting and Grinding, Shanghai, PR China, 1994, pp. 354–359.
8.
CheungS. M.An investigation of roundness improvement in taper turning using forecasting compensatory control. MPhil thesis, The Hong Kong Polytechnic University, 1996.
9.
YangG.YuanJ.NiJ.Real time cutting force induced error compensation on a turning center. Int. J. Mach. Tools Mf., 1997, 37(11), 1597–1610.
10.
YandayanY.BurdekinM.In-process dimensional measurement and control of workpiece accuracy. Int. J. Mach. Tools Mf., 1997, 37(10), 1423–1439.
11.
ChengK.KirkwoodD.ChenX. H.Forecasting and control of the component accuracy in turning with advanced algorithms. In Proceedings of International Conference on Manufacturing Automation, Hong Kong, 1997, pp. 1075–1078.
12.
TakeuchiY.SakamotoM.SataT.Improvement in the working accuracy of a NC lathe by compensation for thermal expansion. Precision Engng, 1982, 4(1), 19–24.
13.
FanK. C.ChenY. H.Design of in-process dimensional error compensator for precision NC turning. J. Chin. Soc. Mech. Engrs, 1996, 17(3), 213–220.
14.
TanakaH.TozawaK.SataT.O-horiM.TaniguchiN.Application of a new straightness measurement method to large machine tool. Ann. CIRP, 1981, 30(1), 455–459.
15.
ShiraishiM.Geometrical adaptive control in NC turning operation. Trans. ASME, J. Engng for Industry, 1984, 106, 75–80.
16.
LiuL.SinhaN. K.ElbestawiM. A.Adaptive control for geometric tracking in turning. Computers in Industry, 1989, 11, 147–159.
17.
FanK. C.ChaoY. H.In-process dimensional control of workpiece during turning. Precision Engng, 1991, 13(1), 27–32.
18.
ShawkyA. M.ElbestawiM. A.In-process evaluation of workpiece geometrical tolerances in bar turning. Int. J. Mach. Tools Mf., 1996, 36(1), 33–46.
19.
ShawkyA. M.ElbestawiM. A.Model-based predictive control of workpiece accuracy in bar turning. Trans. ASME, J. Mfg Sci. Engng, 1998, 120, 57–67.
20.
UdaY.KohnoT.YazawaT.In-process measurement and workpiece-referred form accuracy control system (WORFAC): Application to cylindrical turning using an ordinary lathe. Precision Engng, 1996, 18(1), 50–55.
21.
HuangW. H.LinS. C.Monitoring surface roughness using force signals for turning. J. Chin. Soc. Mech. Engrs, 1997, 18(1), 23–29.
22.
KimK.EmanK. F.WuS. M.In-process control of cylindricity in boring operations. Trans. ASME, J. Engng for Industry, 1987, 109, 291–296.
23.
FungE. H. K.CheungS. M.LeungT. P.Implementation of an error forecasting and compensation system for roundness improvement in taper turning. Computers in Industry, 1998, 35, 109–120.
24.
WuS. M.NiJ.Precision machine without precise machinery. Ann. CIRP, 1989, 38, 533–536.
25.
SchramaP. R. J.FranseJ.The precision cutting process as a non-linear closed loop system. Precision Engng, 1988, 10, 199–207.
26.
FassoisS. D.EmanK. F.WuS. M.A fast algorithm for on-line machining process modeling and adaptive control. Trans. ASME, J. Engng for Industry, 1989, 111, 133–139.
27.
TejaS. R.JayasinghT.Characterisation of ground surface profiles—a comparison of AR, MA, ARMA modelling approaches. Int. J. Mach. Tools Mf., 1993, 33(1), 103–109.
28.
FungE. H. K.ChungA. P. L.Using ARMA models to forecast workpiece roundness error in a turning operation. Appl. Math. Modelling, 1999, 23, 567–585.
29.
YangM. Y.ChoiJ. G.A tool deflection compensation system for end milling accuracy improvement. Trans. ASME, J. Mfg Sci. Engng, 1998, 120, 222–229.
30.
LiC. J.LiS. Y.On-line roundness error compensation via P-integrator learning control. Trans. ASME, J. Engng for Industry, 1992, 114, 476–480.
31.
ChenM. Q.YangC. H.Dynamic compensation technology of the spindle error motion of a precision lathe. Precision Engng, 1989, 11(3), 135–138.
32.
OkazakiY.A micro-positioning tool post using a piezoelectric actuator for diamond turning machines. Precision Engng, 1990, 12(3), 151–156.
33.
KimJ. D.KimD. S.Waviness compensation of precision machining by piezo-electric micro cutting device. Int. J. Mach. Tools Mf., 1998, 38, 1305–1322.
34.
YourS. B.Precision control on the Winchester disc flatness in face-turning operation. PhD thesis, The University of Wisconsin at Madison, 1987.
35.
FungE. H. K.YangS. M.An error separation technique for measuring straightness motion error of a linear slide. Measmt Sci. Technol., 2000, 11(10), 1515–1521.
36.
ZhangG. X.WangR. K.Four-point method of roundness and spindle error measurements. Ann. CIRP, 1992, 42(1), 593–596.
37.
ZhangG. X.ZhangY. H.YangS. M.LiZ.A multipoint method for spindle error motion measurement. Ann. CIRP, 1997, 46(1), 441–445.
38.
LjungL.SoderstromT.Theory and Practice of Recursive Identification, 1986 (MIT Press, Cambridge, Massachusetts).
