SITUATION

A control system design, in block diagram form, has been submitted for performance analysis by analog computer simulation techniques or by use of a packaged digital simulation program. The performance of the system should include the displacement and the velocity (the step and ramp response) of the output shaft for several different values the forward gain, K, and also for several different values of the velocity feedback gain, K _t, for different settings of K. Also it will be desired to monitor the system error, e, as the simulation is in progress. The control system block diagram is as follows:

REQUIREMENT

1. Convert the system block diagram for an equivalent analog computer schematic.

2. Show any schematic that might be needed for both a step and ramp input.

3. Should the simulation be done with a digital packaged program, determine a suitable step size that might be considered for integration routines.

SOLUTION

Since the system has a differentiating block, sK _t, (which is very difficult to simulated by both analog and digital methods) the block diagram is rearranged so that this block is ahead of the integrator as follows:

1. The analog computer equivalent schematic is arranged to have a pick off point for the system error at e, and the various gain controls may be easily manipulated for several different settings. Also, since all op-amps operate in the inverted mode and all loops are for negative feedblock, all loop are to have an odd...