0723514931 DR LERATO ABORTION CLINICS In WITBANK, SABIE, DELMAS, BREYTEN
Ultrasonic Tracking System Group # 4 Bill Harris Sabie Pettengill Enrico Telemaque Eric Zweighaft.
-
Upload
bryce-warner -
Category
Documents
-
view
215 -
download
1
Transcript of Ultrasonic Tracking System Group # 4 Bill Harris Sabie Pettengill Enrico Telemaque Eric Zweighaft.
Ultrasonic Tracking Ultrasonic Tracking SystemSystem
Group # 4Group # 4
Bill HarrisBill Harris
Sabie PettengillSabie Pettengill
Enrico TelemaqueEnrico Telemaque
Eric ZweighaftEric Zweighaft
IntroductionIntroduction What is our project?What is our project?
Pan and tilt implemented system tracking an ultrasonic Pan and tilt implemented system tracking an ultrasonic beacon which sends a signal to 3 ultrasonic receivers, is beacon which sends a signal to 3 ultrasonic receivers, is carried around the room by a team membercarried around the room by a team member
How does it work?How does it work? The signal coming from an ultrasonic transmitters is The signal coming from an ultrasonic transmitters is
measured at three different locationsmeasured at three different locations The difference in the time the signal is received at each The difference in the time the signal is received at each
sensor is used to calculate a distance relationship sensor is used to calculate a distance relationship Why is this project practical?Why is this project practical?
Mitsubishi Motor company uses a similar design in their Mitsubishi Motor company uses a similar design in their automobiles for a collision avoidence systemautomobiles for a collision avoidence system
Various pest and animal repellent systems use Various pest and animal repellent systems use ultrasonic waves for tracking and repelling.ultrasonic waves for tracking and repelling.
ObjectiveObjective Simulation of pan & tilt system used as a cost Simulation of pan & tilt system used as a cost
efficient method to determine:efficient method to determine: Motor required to drive systemMotor required to drive system Gear, belt and pulley combination neededGear, belt and pulley combination needed Response of system to motor, gear, belt and Response of system to motor, gear, belt and
pulleypulley Maximum performance variables for system Maximum performance variables for system Rough estimate of system response to Rough estimate of system response to
sample payloadsample payload Chance to show that we were paying Chance to show that we were paying
attention in all those math classesattention in all those math classes
SpecificationsSpecifications The system will track objects between 2 and 10 The system will track objects between 2 and 10
meters from the arraymeters from the array The system will track objects between 0 and 2 The system will track objects between 0 and 2
meters off the groundmeters off the ground The system will track items within .5 degree of The system will track items within .5 degree of
accuracy (within 10 cms of the object with accuracy (within 10 cms of the object with beacon)beacon)
The system must be able to track the beacon at The system must be able to track the beacon at the speed of a human walking (.64 rad/sec)the speed of a human walking (.64 rad/sec)
Major Change in DesignMajor Change in Design
With our previous sensor structure, With our previous sensor structure, there was not a large enough motor that there was not a large enough motor that could handle the torquecould handle the torque
We decided make a more compact We decided make a more compact sensor structure which allowed us to go sensor structure which allowed us to go with a much smaller motor in the with a much smaller motor in the Pittman 8000 series. Pittman 8000 series.
The sensor structure was made L shaped The sensor structure was made L shaped instead of T shaped to allow for a instead of T shaped to allow for a simpler timer circuitsimpler timer circuit
MotorMotor
Pittman GM8724S017Pittman GM8724S017 19.5:1 internal gearing ratio19.5:1 internal gearing ratio Encoder mounted directly to rotor Encoder mounted directly to rotor
increases accuracy of encoder (encoder increases accuracy of encoder (encoder is not geared down)is not geared down)
External transmission gives additional External transmission gives additional reduction ratio of 3:1reduction ratio of 3:1
MotorMotor
Pittman GM8724S017Pittman GM8724S017 Larger gearing ratio does not allow us Larger gearing ratio does not allow us
to meet our speed requirementsto meet our speed requirements Smaller gearing ratio does not allow us Smaller gearing ratio does not allow us
to meet our torque requirementsto meet our torque requirements Gains must be chosen carefully to Gains must be chosen carefully to
remain inside the feasible range for remain inside the feasible range for both speed and torqueboth speed and torque
MotorMotor
0 2 4 6 8 10 12 14 16 18 20-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Desired Input and Actual Output for Theta1
time
radia
ns
inputtheta1
0 2 4 6 8 10 12 14 16 18 20-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Desired Input and Actual Output for Theta1
time
radia
ns
inputtheta1
•SimulationSimulation•Sinusoidal Sinusoidal inputinput•Frequency of Frequency of 0.63 rad/s0.63 rad/s
MotorMotor
•Speed vs. Torque Speed vs. Torque plotplot
•Shows that Shows that motor is well motor is well within limits, as within limits, as long as gains long as gains are kept at are kept at reasonable reasonable levelslevels
0 0.05 0.1 0.15 0.20
200
400
600
800
1000
1200
motor 1 torque (Nm)
mot
or 1
vel
ocity
(ra
d/s)
feasible
not feasible
Pittman GM8724S010
0 0.05 0.1 0.15 0.20
200
400
600
800
1000
1200
motor 2 torque (Nm)
mot
or 2
vel
ocity
(ra
d/s)
feasible
not feasible
Pittman GM8724S010
0 0.05 0.1 0.15 0.20
200
400
600
800
1000
1200
motor 1 torque (Nm)
mot
or 1
vel
ocity
(ra
d/s)
feasible
not feasible
Pittman GM8724S010
0 0.05 0.1 0.15 0.20
200
400
600
800
1000
1200
motor 2 torque (Nm)
mot
or 2
vel
ocity
(ra
d/s)
feasible
not feasible
Pittman GM8724S010
ControllerController
By intuitive By intuitive adjustment of adjustment of gains, a reasonable gains, a reasonable response was response was obtainedobtained But “guessing” is But “guessing” is
not a valid design not a valid design approachapproach
0 0.5 1 1.5 2 2.5 30
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1Theta1 from 1 radian to zero
Time (in Sec)
Rad
ians
0 0.5 1 1.5 2 2.5 30
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1Theta1 from 1 radian to zero
Time (in Sec)
Rad
ians
0 2 4 6 8 10 12 14 16 18 20-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Desired Input and Actual Output for Theta1
time
radi
ans
inputtheta1
0 2 4 6 8 10 12 14 16 18 20-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1Desired Input and Actual Output for Theta1
time
radi
ans
inputtheta1
ControllerController
SISO Design tool was usedSISO Design tool was used Linearized model was obtained using the Linearized model was obtained using the
linearlization routines providedlinearlization routines provided Alternatively, the “linmod” command could be Alternatively, the “linmod” command could be
called to create a linear State Space model from called to create a linear State Space model from the Simulink Diagramthe Simulink Diagram
This allows the designer to view pole/zero This allows the designer to view pole/zero locations, bode plots, AND response plots all locations, bode plots, AND response plots all at the same time, and adjust poles, zeros, and at the same time, and adjust poles, zeros, and gains in any of these formatsgains in any of these formats
ControllerController
SISO WindowSISO Window Step ResponseStep Response
Overshoot is very undesirableOvershoot is very undesirable
Step Response
Time (sec)
Am
plit
ud
e
0 0.05 0.1 0.15 0.2 0.25 0.3 0.350
0.2
0.4
0.6
0.8
1
1.2
1.4
ControllerController
SISO WindowSISO Window Step ResponseStep Response
PM = 98.2° GM = Inf. Zero overshoot, PM = 98.2° GM = Inf. Zero overshoot, 1% e1% essss
Step Response
Time (sec)
Am
plit
ud
e0 0.05 0.1 0.15
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Notes on ControllerNotes on Controller
Because of assumptions made in order Because of assumptions made in order to linearize the system, this controller to linearize the system, this controller does not perform perfectly on the non-does not perform perfectly on the non-linearized model, so some adjustments linearized model, so some adjustments will have to be made during assembly will have to be made during assembly and testingand testing
We may wish to add an Integral term We may wish to add an Integral term later to cancel the 1% overshootlater to cancel the 1% overshoot Does not seem necessary now- it would only Does not seem necessary now- it would only
hurt our transient response, and require hurt our transient response, and require more torque and speed from the motormore torque and speed from the motor
Justification for Sensor Justification for Sensor PartsParts
Given the cost of larger motors, needed Given the cost of larger motors, needed to have a design with a small moment of to have a design with a small moment of inertiainertia
The higher the clock frequency of timer The higher the clock frequency of timer circuit, the smaller our sensor structure circuit, the smaller our sensor structure has to behas to be
The cheapest TTL components had a The cheapest TTL components had a maximum functional frequency of 5 MHzmaximum functional frequency of 5 MHz
Chose an oscillator accordinglyChose an oscillator accordingly
CostCost
Pan and Tilt PartsPan and Tilt Parts
Total $478.64Total $478.64
PartPart Part #Part # QuanityQuanity Price Price Total $Total $$$
MotorMotor GM8724S0GM8724S017 17 22 192.86192.86 385.72385.72
Gear Gear (large)(large)
A 6A 6-A 6A 6-75NF01812 75NF01812 22 15.1515.15 30.3030.30
Gear Gear (small)(small)
A 6A 6-A 6A 6-25DF01806 25DF01806 22 7.767.76 15.5215.52
Carbon Carbon FiberFiber
T155-5T155-5 11 43.4043.40 43.4043.40
Timing BeltTiming Belt A6Z16-A6Z16-C018 C018 22 1.861.86 3.703.70
Additional CostsAdditional Costs
Total Amount for Timing Circuit and Total Amount for Timing Circuit and Sensors: $46.52Sensors: $46.52
Total Cost for project: $533.84Total Cost for project: $533.84
February
Week 2 Week 3 Week 4
Hardware
Placing parts and payload on CAD
drawings to calculate P,I,M
values for Matlab simulation (Bill,
Sabie)
Hardware - CAD designed payload
added to Ben’s CAD drawings system and edited P,I,M values
are calculated(Eric, Sabie)
Final design specifications are
met(All members)
Parts are ordered(Eric, Sabie)
Software
Simulation of pan and tilt system to
obtain feasibility and performance of test
motor with a test payload
(Bill)
Final Motor feasibility simulation with payload on pan
and tilt system(Bill, Enrico)
Testing of control system’s ability to
track a signal using amplitude, or
distance and time measurements(All members)
Reports Presentation writeup (Enrico Eric)
Proposal writeup (Sabie, Enrico)
TBD
March
Weeks 1-2 Week 3 Week 4
Hardware
Sensor development with focus on time\
distance relationship(Eric, Sabie)
Encoder and amplifier properties
researched(Bill, Enrico)
Design model assembled
(Enrico, Sabie)
Sensor assembly(Bill, Eric)
Further tolerance testing of physical
equipment
Software
Current Feedback control analyzing and testing to find proper gains for
accurate tracking(Bill, Enrico)
Encoder and amplifier properties
simulated(Eric, Sabie)
Testing and fine tuning of control feedback system
(Bill, Sabie)
Sensor testing with system
(Enrico, Eric)
Test mechanics of system in terms of
motion(Bill, Enrico)
Test mechanics of system in terms of
tracking(Eric, Sabie)
Reports Progress Report(All members)
TBD TBD