The assembly process of the mechanical and electrical parts was done in the Advanced Manufacturing Lab (AML) with the help of Mircea Cormos and Prof. Stanford Meek. In this design the last link is movable, so that different robot configurations can be used (see Figure 22).
There are three different motors to drive the three links, and six sensors (three for position and three for velocity), to read the current position and velocity for each link to be used in the feedback control loop.
Figure 21: The interface window for the PID controller simulator.
Figure 22: The physical three-link robot manipulator.
This robot can be controlled using analog control by interfacing it with an analog PID controller. Digital control can also be used by interfacing the robot with either a workstation (Sun, HP, etc.) or a PC via the standard RS232. This requires an A/D and D/A chip to be connected to the workstation (or the PC) and an amplifier that provides enough power to drive the motors. Figure 23 shows an overall view of the different interfaces and platforms that can control the robot. A summary of this design can be found in [10].
Figure 23: Controlling the robot using different schemes.