Disturbance observer based robot control algorithms provide good control performance while giving a straightforward method of gain selection. Unfortunately, the stability of these algorithms has not been shown rigorously for nonlinear systems such as robots. This paper demonstrates that a disturbance observer based algorithm can be made equivalent to the well-known passivity-based approaches of Sadegh and Horowitz, and Slotine and Li. This is accomplished by choosing a specific design of the Q(s) filter (described in the paper) of the disturbance observer. By doing so, the stability of the disturbance observer based approach can be proven rigorously. An additional benefit of the equivalence of the two approaches is the ability to combine an adaptive controller to the disturbance observer based approach.

1.
Bickel, R., and Tomizuka, M., 1994, “Design of a Robust Tracking Controller in the Discrete Time Domain,” Proceedings of the 3rd International Workshop on Advanced Motion Control, Berkeley, CA, pp. 648–659.
2.
Bickel, R., and Tomizuka, M., 1995, “Disturbance Observer Based Hybrid Impedance Control,” Proceedings of the American Control Conference, Seattle, WA, pp. 729–733.
3.
Desoer, C. A., and Vidyasagar, M., 1975, Feedback Systems: Input-Output Properties, Academic Press, New York, NY.
4.
Endo, S., Tomizuka, M., and Hori, Y., 1993, “Robust Digital Tracking Controller Design for High-Speed Positioning Systems,” Proceedings of the American Control Conference, San Francisco, CA, pp. 2494–2498.
5.
Hori, Y., Shimura, K., and Tomizuka, M., 1992, “Position/Force Control of Multi-Axis Robot Manipulator Based on the TDOF Robust Servo Controller for Each Joint,” Proceedings of the American Control Conference, pp. 753–757.
6.
Kang, C. G., Kao, W. W., Boals, M., and Horowitz, R., 1988, “Modeling Identification and Simulation of a Two-Link SCARA Manipulator,” Symposium on Robotics, ASME 1988 Winter Annual Meeting, pp. 393–407.
7.
Komada, S., Ohnishi, K., and Hori, T., 1991, “Hybrid Position/Force Control of Robot Manipulators Based on Acceleration Controller,” Proceedings of the IEEE International Conference on Robotics and Automation, Sacramento, CA, pp. 48–55.
8.
Komada, S., Shin, J., Ishida, M., Ohnishi, K., and Hori, T., 1992, “Simplification of Inverse Kinematics Routine of Robot Manipulators using Disturbance Observer in Task Space,” Proceedings of the IEEE Conference on Robotics and Automation, pp. 1381–1386.
9.
Lee, H., and Tomizuka, M., 1994, “Robust High-Speed Servo-Controllers for Micropositioning Systems,” Proceedings of the 3rd International Workshop on Advanced Motion Control, Berkeley, CA, pp. 633–642.
10.
Nakao, M., Ohnishi, K., and Miyachi, K., 1987, “A Robust Decentralized Joint Control Based on Interference Estimation,” Proceedings of the IEEE International Conference on Robotics and Automation, pp. 326–331.
11.
Ohnishi, K., and Murakami, T., 1989, “Advanced Motion Control in Robotics,” Proceedings of the IEEE IECON, pp. 356–359.
12.
Ohnishi
K.
,
Nakao
M.
,
Ohnishi
K.
, and
Miyachi
K.
,
1987
, “
Microprocessor Controlled DC Motor for Load-Insensitive Position Servo System
,”
IEEE Transactions on Industrial Electronics
, Vol.
IE-34
, No.
1
, pp.
44
49
.
13.
Ortega
R.
, and
Spong
M.
,
1989
, “
Adaptive Motion Control of Rigid Robots: a Tutorial
,”
Automatica
, Vol.
25
, No.
6
, pp.
877
888
.
14.
Sadegh, N., and Horowitz, R., 1987, “Stability Analysis of an Adaptive Controller for Robotic Manipulators,” Proceedings of the IEEE International Conference on Robotics and Automation, pp. 1223–1229.
15.
Sadegh
N.
, and
Horowitz
R.
,
1990
, “
Stability and Robustness Analysis for a Class of Adaptive Controllers for Robotic Manipulators
,”
International Journal of Robotics Research
, Vol.
9
, No.
3
, pp.
74
92
.
16.
Shimura, K., Sugai, M., and Hori, Y., 1991, “A Novel Robot Motion Control Based on the Decentralized Robust Servomechanism for Each Joint,” Proceedings of the IEEE IECON, pp. 1283–1288.
17.
Slotine
J. J. E.
, and
Li
W.
,
1987
, “
On the Adaptive Control of Robot Manipulators
,”
International Journal of Robotics Research
, Vol.
6
, No.
3
, pp.
44
59
.
18.
Slotine, J. J. E., and Li, W., 1991, Applied Nonlinear Control, Prentice Hall, Englewood Cliffs, NJ.
19.
Tesfaye, A., 1994, “Theory and Implementation of Robust Performance Digital Servo Controllers,” PhD thesis, University of California at Berkeley, Berkeley, CA.
20.
Umeno, T., and Hori, Y., 1989, “Robust DC Servosystem Design Based on the Parameterization of Two Degrees of Freedom Control Systems,” Proceedings of the IEEE IECON, pp. 313–318.
21.
Umeno, T., and Hori, Y., 1990, “Two Degrees of Freedom Controller for Robust Servomechanism,” Proceedings of the IEEE International Workshop on Advanced Motion Control, Yokohama, Japan, pp. 47–56.
22.
Umeno
T.
, and
Hori
Y.
,
1991
, “
Robust Speed Control of DC Servo-motors Using Modern Two Degrees-of-Freedom Controller Design
,”
IEEE Transactions on Industrial Electronics
, Vol.
38
, No.
5
, pp.
363
368
.
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