A robust control scheme for flexible arms with friction in the joints

A general control scheme to control flexible arms with friction in the joints is proposed in this paper. This scheme presents the advantage of being robust in the sense that it minimizes the effects of the Coulomb friction existing in the motor and the effects of changes in the dynamic friction coefficient. A justification of the robustness properties of the scheme is given in terms of the sensitivity analysis

Work in Progress: The WSU Model for Engineering Mathematics Education

This paper summarizes progress to date on the WSU model for engineering mathematics education, an NSF funded curriculum reform initiative at Wright State University. The WSU model seeks to increase student retention, motivation and success in engineering through application-driven, just-in-time engineering math instruction. The WSU approach involves the development of a novel freshman-level engineering mathematics course EGR 101, as well as a large-scale restructuring of the engineering curriculum. By removing traditional math prerequisites and moving core engineering courses earlier in the program, the WSU model shifts the traditional emphasis on math prerequisite requirements to an emphasis on engineering motivation for math, with a just-in-time structuring of the new math sequence. This paper summarizes the development to date of the WSU model for engineering mathematics education, including a preliminary assessment of student performance and perception during the initial implementation of EGR 101. In addition, an assessment of first-year retention results is anticipated in time for the conference

Design and control of a two-degree-of-freedom lightweight flexible arm

Abstract: "This report describes the design and control of a two-joint, two-link flexible arm. Our purpose has been to build an efficient arm in the sense that most of the energy provided by the motors is spent in doing the task (moving the tip mass) instead of moving the arm structure. In order to achieve that, we designed a flexible arm that has most of its mass concentrated on the tip. We also wanted to decouple radial tip motions from angular tip motions. The special mechanical configuration that fulfills all these specifications is described in Section 2.Section 3 describes the control scheme of this arm. An important problem with controlling it was the large Coulomb friction of the motors. A two-nested-loop multivariable controller has been used. The inner loop controls the position of the motors while the outer loop controls the tip position. The resolved acceleration method is generalized to control this flexible arm. The compliance matrix was used to model the oscillations of the structure, and was included in the decoupling/linearizing term of this controller. Experimental results are given in Section 4, and conclusions are drawn in Section 5.