C H A P T E R 1
Introduction to Control Systems
There are, in general, no unique solutions to the following exercises and
problems. Other equally valid block diagrams may be submitted by the
student.
Exercises
E1.1 A microprocessor controlled laser system:
Controller Process
Error Current i(t)
Desired Micro- Power
Laser
power - processor out
output
Measurement
Measured
Power
power
Sensor
E1.2 A driver controlled cruise control system:
Controller Process
Foot pedal Car and
Desired Actual
Driver
speed - Engine auto
speed
Measurement
Visual indication of speed
Speedometer
E1.3 Although the principle of conservation of momentum explains much of
the process of fly-casting, there does not exist a comprehensive scientific
explanation of how a fly-fisher uses the small backward and forward mo-
tion of the fly rod to cast an almost weightless fly lure long distances (the
1
,2 CHAPTER 1 Introduction to Control Systems
current world-record is 236 ft). The fly lure is attached to a short invisible
leader about 15-ft long, which is in turn attached to a longer and thicker
Dacron line. The objective is cast the fly lure to a distant spot with dead-
eye accuracy so that the thicker part of the line touches the water first
and then the fly gently settles on the water just as an insect might.
Wind
Fly-fisher Controller disturbance
Process
Desired
Mind and Rod, line, Actual
position of - body of the and cast position
of the fly
the fly fly-fisher
Measurement
Vision of
Visual indication the fly-fisher
of the position of
the fly
E1.4 An autofocus camera control system:
One-way trip time for the beam
Conversion factor
K1 (speed of light or
sound)
Beam
Emitter/ Distance to subject
Receiver
Beam return Subject
Lens focusing
motor
Lens
, Exercises 3
E1.5 Tacking a sailboat as the wind shifts:
Wind
Controller Actuators Process
Error
Desired Sailor Rudder and Sailboat Actual
sailboat - sail adjustment sailboat
direction direction
Measurement
Measured sailboat direction
Gyro compass
E1.6 An automated highway control system merging two lanes of traffic:
Controller Actuators Process
Error Embedded
Desired Active Actual
Brakes, gas or
gap - computer steering vehicle gap
Measurement
Measured gap
Radar
E1.7 Using the speedometer, the driver calculates the difference between the
measured speed and the desired speed. The driver throotle knob or the
brakes as necessary to adjust the speed. If the current speed is not too
much over the desired speed, the driver may let friction and gravity slow
the motorcycle down.
Controller Actuators Process
Error
Desired Driver Actual
Throttle or Motorcycle
speed - brakes
motorcycle
speed
Measurement
Visual indication of speed
Speedometer
, 4 CHAPTER 1 Introduction to Control Systems
E1.8 Human biofeedback control system:
Controller Process
Message to
blood vessels
Desired Hypothalumus Human body
Actual
body - body
temp
temp
Measurement
Visual indication of
body temperature TV display Body sensor
E1.9 E-enabled aircraft with ground-based flight path control:
Corrections to the Controller Aircraft
flight path
Desired Flight
Flight - Gc(s) G(s)
Path
Path Health
Meteorological Location
data Parameters and speed
Optimal
flight path
Ground-Based Computer Network
Optimal
flight path Location
and speed
Meteorological Health
- data Parameters
Desired Gc(s) G(s) Flight
Corrections to the
Flight flight path Path
Path Controller Aircraft
E1.10 Unmanned aerial vehicle used for crop monitoring in an autonomous
mode:
Trajectory Controller UAV
error
Specified
Gc(s) G(s) Flight
Flight - Trajectory
Trajectory
Sensor
Location with Map Ground
respect to the ground photo
Correlation Camera
Algorithm
Introduction to Control Systems
There are, in general, no unique solutions to the following exercises and
problems. Other equally valid block diagrams may be submitted by the
student.
Exercises
E1.1 A microprocessor controlled laser system:
Controller Process
Error Current i(t)
Desired Micro- Power
Laser
power - processor out
output
Measurement
Measured
Power
power
Sensor
E1.2 A driver controlled cruise control system:
Controller Process
Foot pedal Car and
Desired Actual
Driver
speed - Engine auto
speed
Measurement
Visual indication of speed
Speedometer
E1.3 Although the principle of conservation of momentum explains much of
the process of fly-casting, there does not exist a comprehensive scientific
explanation of how a fly-fisher uses the small backward and forward mo-
tion of the fly rod to cast an almost weightless fly lure long distances (the
1
,2 CHAPTER 1 Introduction to Control Systems
current world-record is 236 ft). The fly lure is attached to a short invisible
leader about 15-ft long, which is in turn attached to a longer and thicker
Dacron line. The objective is cast the fly lure to a distant spot with dead-
eye accuracy so that the thicker part of the line touches the water first
and then the fly gently settles on the water just as an insect might.
Wind
Fly-fisher Controller disturbance
Process
Desired
Mind and Rod, line, Actual
position of - body of the and cast position
of the fly
the fly fly-fisher
Measurement
Vision of
Visual indication the fly-fisher
of the position of
the fly
E1.4 An autofocus camera control system:
One-way trip time for the beam
Conversion factor
K1 (speed of light or
sound)
Beam
Emitter/ Distance to subject
Receiver
Beam return Subject
Lens focusing
motor
Lens
, Exercises 3
E1.5 Tacking a sailboat as the wind shifts:
Wind
Controller Actuators Process
Error
Desired Sailor Rudder and Sailboat Actual
sailboat - sail adjustment sailboat
direction direction
Measurement
Measured sailboat direction
Gyro compass
E1.6 An automated highway control system merging two lanes of traffic:
Controller Actuators Process
Error Embedded
Desired Active Actual
Brakes, gas or
gap - computer steering vehicle gap
Measurement
Measured gap
Radar
E1.7 Using the speedometer, the driver calculates the difference between the
measured speed and the desired speed. The driver throotle knob or the
brakes as necessary to adjust the speed. If the current speed is not too
much over the desired speed, the driver may let friction and gravity slow
the motorcycle down.
Controller Actuators Process
Error
Desired Driver Actual
Throttle or Motorcycle
speed - brakes
motorcycle
speed
Measurement
Visual indication of speed
Speedometer
, 4 CHAPTER 1 Introduction to Control Systems
E1.8 Human biofeedback control system:
Controller Process
Message to
blood vessels
Desired Hypothalumus Human body
Actual
body - body
temp
temp
Measurement
Visual indication of
body temperature TV display Body sensor
E1.9 E-enabled aircraft with ground-based flight path control:
Corrections to the Controller Aircraft
flight path
Desired Flight
Flight - Gc(s) G(s)
Path
Path Health
Meteorological Location
data Parameters and speed
Optimal
flight path
Ground-Based Computer Network
Optimal
flight path Location
and speed
Meteorological Health
- data Parameters
Desired Gc(s) G(s) Flight
Corrections to the
Flight flight path Path
Path Controller Aircraft
E1.10 Unmanned aerial vehicle used for crop monitoring in an autonomous
mode:
Trajectory Controller UAV
error
Specified
Gc(s) G(s) Flight
Flight - Trajectory
Trajectory
Sensor
Location with Map Ground
respect to the ground photo
Correlation Camera
Algorithm
