Industrial robots have found great potential in applications to assembly-line automation. Programmable robotbased assembly systems are often needed, in particular for circumstances in which special assembly equipment is not available or well-trained operators could not be employed economically. Robots with enough compliance can perform not only classic automation tasks, such as spot welding, cargo carrying, etc., but also can operate those tasks which demand the compliant motion capacity of robots. Therefore, the research on robot compliance is especially important for parts assembly by robots, where robot compliant motions and manipulations are essential requirements. This paper presents a number of important issues in robot compliance research, including the specification of robot end-effector compliance; properties of a robot compliance matrix at its end-effector; discussions on passive compliance and active compliance and their comparisons; and derivation of the compliance at the endeffector required for tasks.

No abstract

No abstract

The modeling, parameters identification, and linear and nonlinear feedback control designs of an electronic throttle control (ETC) system is considered. A commercially available ETC system made by Bosch is selected for our investigation. The unknown parameters identified are used in designing linear and nonlinear controllers. Simulations and extensive experiments were conducted. A real-time linear controller was implemented with the xPC Target. The ETC model is then extended to a separately excited nonlinear dc motor model. The nonlinear controller is designed using the input-output feedback linearization technique; the extension proves to be of solid theoretical value. The results presented in this paper can be considered as an interesting and important case study encompassing system modeling, parameters identification, linear and nonlinear controller designs, and real-time control. The techniques and methodology developed are applicable to similar and/or other types of systems.