0.0 FIGURE 101.8 Articulated robot work envelope FIGURE 101.9 The SCARA configuration. Source: T. Owen, Assembly with Robots, Englewood Cliffs, N J. Prentice-Hall 985. With permission. speeds are possible. The articulated arm is good for tasks involving multiple insertions, complex motions, and varied tool orientations. The versatility of this configuration makes it applicable to a variety of tasks, so the user has fewer limitations on the use of the robot. However, the same features that give this robot its advantages lead to certain disadvantages. The geometry is complex, and the resulting kinematic equations are quite intricate. Straight-line motion is difficult to coordinate. Control is generally more difficult than for other geometries with associated increase in cost. Here again, arm resolution is not fixed throughout the workspace. Additionally, ne dynamics of an articulated arm vary widely throughout the workspace, so that performance will vary over the workspace for a fixed controller. In spite of these disadvantages, the articulated arm has been applied to a wide variety of research and industrial tasks, including spray painting, clean room tasks, machine loading, and parts-finishing tasks SCARA Configuration The SCARA( Selectively Compliant Assembly Robot Arm) configuration consists of two revolute joints and a linear joint(RRP), as shown in Fig. 101.9. This configuration is significantly different from the spherical figuration, since the axes for all joints are always vertical. In addition to the first three degrees of freedom (DOF), the SCARa robot will often include an additional rotation about the last vertical link to aid in orientation of parts. The work envelope of the SCARA robot is illustrated in Fig. 101.10. The SCARA configuration is the ewest of the configurations discussed here, and was developed by Professor Hiroshi Makino of Yamanashi University, Japan. e 2000 by CRC Press LLC© 2000 by CRC Press LLC speeds are possible. The articulated arm is good for tasks involving multiple insertions, complex motions, and varied tool orientations. The versatility of this configuration makes it applicable to a variety of tasks, so the user has fewer limitations on the use of the robot. However, the same features that give this robot its advantages lead to certain disadvantages. The geometry is complex, and the resulting kinematic equations are quite intricate. Straight-line motion is difficult to coordinate. Control is generally more difficult than for other geometries, with associated increase in cost. Here again, arm resolution is not fixed throughout the workspace. Additionally, the dynamics of an articulated arm vary widely throughout the workspace, so that performance will vary over the workspace for a fixed controller. In spite of these disadvantages, the articulated arm has been applied to a wide variety of research and industrial tasks, including spray painting, clean room tasks, machine loading, and parts-finishing tasks. SCARA Configuration The SCARA (Selectively Compliant Assembly Robot Arm) configuration consists of two revolute joints and a linear joint (RRP), as shown in Fig. 101.9. This configuration is significantly different from the spherical configuration, since the axes for all joints are always vertical. In addition to the first three degrees of freedom (DOF), the SCARA robot will often include an additional rotation about the last vertical link to aid in orientation of parts. The work envelope of the SCARA robot is illustrated in Fig. 101.10. The SCARA configuration is the newest of the configurations discussed here, and was developed by Professor Hiroshi Makino of Yamanashi University, Japan. FIGURE 101.8 Articulated robot work envelope. FIGURE 101.9 The SCARA configuration. (Source: T. Owen, Assembly with Robots, Englewood Cliffs, N.J.: Prentice-Hall, 1985. With permission.) Xmax Ymin Ymax Z max Z min = 0.0 Xmin 0˚