TEAM 7

Joel HandyRob SchugmannJon Addison

STAR SEARCH

CONTROL SYSTEMS DESIGN

Final Presentation

Final Presentation Outline•Project Overview

•Objective

•Review original design

•Describe project construction and functional tests

•Discuss successes and challenges

•Future Development

Final Presentation Outline

Project OverviewProject Overview

Using a telescope can be entertaining but also frustrating

Difficulties include

•Locating a celestial object

•Keeping the object within view over time

Project OverviewProject Overview Cont

These difficulties can be overcome through the design of a motorized telescope that can track a celestial object while remaining resistant to disturbances.

Original Goals

Original Goals

• Design a self-calibrating computer-positioning telescope

• Should withstand disturbances and stay centered on the desired object

•Should be easy to use while remaining relatively cheap to implement

Design Concerns & Specifications

• Speed

Point to point movement and tracking require different speeds

• Resolution

A small change in telescope position yields a large change in the field of view

Speed

Specifications for Point to Point Movement

•72°.00 / secSpecifications for Tracking Speed

•360°/23.93446743 hrs.•15°.04107000 / hr.

Speed

Resolution

Resolution is the smallest movement possible in a system

High Resolution Requirements- 0.25 degrees- Half of the field of view at medium

magnification - Increase resolution by gearing down

the system

Resolution

Resolution and Accuracy

High Resolution Requirements- 0.25 degrees- Half of the field of view at medium

magnification - Increase resolution by gearing down

the systemAccuracy

.-0.25 degrees-Any more error and objects will leave

field of view

Resolution

Project Development

•Linear Simulation

•Motor Selection

•Non-linear Simulation

•Experimental Analysis

Project Development

Linear

Simulation

Developed mathematical model of system

Used robotic parameters to obtain required torques for a given path

Linear Simulation

Torque ConstraintsTorque

Constraints

0 0.5 1 1.5 2 2.5 3 3.5-0.06

-0.04

-0.02

0

0.02

0.04

0.06

Pa

n T

orq

ue

0 0.5 1 1.5 2 2.5 3 3.5-0.3

-0.2

-0.1

0

0.1

Tilt

To

rqu

e

Motor and Gear SelectionMotor Selection

Motor (Pittman GM8724S016)•19.5:1 internal gear ratio•Max continuous torque of .29 N/m

Gears •External gear ratio of 4:1•Overall gear ratio of 80:1

RLtool

RLtoolStep Response

Time (sec)

Am

plitu

de

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.90

0.2

0.4

0.6

0.8

1

1.2

1.4From: r

To:

y

Step Response

Time (sec)

Am

plitu

de

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 20

0.2

0.4

0.6

0.8

1

1.2

1.4From: r

To:

y

Pan Step Response

Tilt Step Response

Non-linear w/o

Non-linear Simulation

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.05

0

0.05

0.1

0.15plot of desired(blue) vs actual(black) for theta1

time (s)

posi

tion

(rad

)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.05

0

0.05

0.1

0.15plot of desired(blue) vs actual(black) for theta2

time (s)

posi

tion

(rad

)

Non-linear w/

Non-linear SimulationFriction Compensation

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.05

0

0.05

0.1

0.15plot of desired(blue) vs actual(black) for theta1

time (s)

posi

tion

(rad

)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-0.05

0

0.05

0.1

0.15plot of desired(blue) vs actual(black) for theta2

time (s)

posi

tion

(rad

)

Testing

Procedure

Created MATLAB script file

-Automated all initialization and operation

-Automated data collection

Testing Procedure

Experimental

Analysis

Experimental AnalysisNo Trajectory Generation

0 0.5 1 1.5 2 2.5 30

0.5

1

1.5Actual Pan Position vs. Desired Pan Position

Po

sit

ion

in

Ra

dia

ns

Time in seconds

0 0.5 1 1.5 2 2.5 3-0.2

0

0.2

0.4

0.6

0.8Actual Tilt Position vs. Desired Tilt Position

Po

sit

ion

in

Ra

dia

ns

Time in seconds

Trajectory generator

Trajectory Generation

Experimental

Analysis

Experimental AnalysisTrajectory Generation

0 0.5 1 1.5 2 2.5 3-0.5

0

0.5

1

1.5Actual Pan Position vs. Desired Pan Position

Po

sit

ion

in

Ra

dia

ns

Time in seconds

0 0.5 1 1.5 2 2.5 3-0.2

0

0.2

0.4

0.6Actual Tilt Position vs. Desired Tilt Position

Po

sit

ion

in

Ra

dia

ns

Time in seconds

Slow tracking

Slow Tracking

0 50 100 150 200 250 300 350-5

0

5

10

15

20x 10

-3 Actual Pan Position vs. Desired Pan PositionP

os

itio

n i

n R

ad

ian

s

Time in seconds

0 50 100 150 200 250 300 350-5

0

5

10

15

20x 10

-3 Actual Tilt Position vs. Desired Tilt Position

Po

sit

ion

in

Ra

dia

ns

Time in seconds

Final results

Initial vs Final Specifications

  Original Goals Final Results

Speed 72 deg/sec 36 deg/sec

Resolution 0.25 deg 0.325 deg

Accuracy 0.25 deg 0.57 deg

     

  Self Positioning Yes

  Withstands Disturbances Yes

  Ease of Use Yes

Challenges

• Excessive Speed

-Telescope Unsafe

-Violent movements

• Trajectory Generator

-Runtime termination

-Initial run errors

Challenges

Project CostProject Cost

Components for StarSearch

Components Manufacturer Part Number Cost Quantity Total Cost

Motor Pittman GM8724S016 112.26 2 224.52

Large Gear Stock Drive A 6A61-00NF03112 19.37 2 38.74

Small Gear Stock Drive A 6A 6-25DF03106 7.4 2 14.8

Timing Belt Stock Drive A 6R 6-1150310 4.12 2 8.24

Project Cost         286.3

           

           

Compass Sensor PNI Corp Vector-2x Magnetometer 50 1 50

Inclinometer US Digital T4 70 1 70

Telescope Jason 304-T 150 1 150

Total Cost         556.3

Future

Developments

• Sensor Integration

-Greater system autonomy

• High resolution encoders

-Would allow for much greater accuracy

• Inclusion of Position data

-Allow users to target objects by name rather than coordinates

Future Developments

Questions?

Questions