Table 4.1. Servo amplifier and servo valve characteristics.

 D/A ---- Servo Amplifiers ------
 Output Gain Bandwidth
 Toint (volts) (ma/volt) (rad/sec) (HZ)
 0 2.5 80 1885 300
 1 2.5 80 1885 300
 2 2.5 16.8 1885 300

 --------------- Servo Valves -----------
 Max. Coil
 Current Bandwidth
 Joint Type (ma) (rad/sec) (HZ)
 0 Pegasus 200 377 60
 1 Pegasus 200 377 60
 2 Sundstrand 42 189 30
 note: Gain = Max. Coil Current / (D/A Output)


Software

 The software environment for controlling the robot was written to run in a multi-user

PDOS operating system. The control system was organized into groups of sensing, action, and

control agents as presented in Figure 4.7. These agents exchanged information through a

dynamic database by way of result, parameter, and activate fields. The result fields stored

data which resulted from an agent's operation. Instructions for accomplishing an agent's

desired task were indicated in parameter fields. The ability to activate or deactivate certain

agents was included in activate fields within the database.

 Sensing agents were those devices through which the work environment of the robot

and the robot states were quantified. Data from the sensing agents were filtered by fourth order

Integral of Time-multiplied Absolute Error (ITAE) data filters before their storage in the

database. The work environment or the sensors' perception of the work environment were

affected by the action agents. Control agents were used to direct the action agents to cause the

robot to move to a desired state. A desired robot state was characterized by setpoints which

were stored in the database and used by the control agents. For decreased calculation time, the

setpoints were specified in units compatible with the result fields rather than physical

measurements. An error calculator was used to compute the difference between the actual robot