Title: Deployable Tactical Aircraft Training Simulator D'T'A'T'S'
1Deployable Tactical Aircraft Training Simulator
(D.T.A.T.S.)
Group 9
L
2GROUP 9Group Members
- Michael Geary (EE)
- James Lewis (EE)
- Guy Maness II (EE)
3WHAT IS D.T.A.TS
- Program developed for military
- It is not a true flight simulator
- Tool used to introduce pilots to surrounding
environment, familiarize them with potential
mission targets - Enable rehearsal of various aspects of mission
including details such as terrain, weather
conditions etc.
4D.T.A.T.S PHYSICAL SPECIFICATIONS
- Trainer needs to be deployable and easily
transportable - Must be capable of operating under harsh
conditions - Able to be reconfigured to simulate multiple
tactical aircraft (Currently based on F/A-18
Hornet) - Must give realistic behaviour and feedback to
trainee - Should be modular in design to facilitate
maintenance - Adequate and accurate documentation must be
provided to operate and support system
5EXISTING D.T.A.T.S SYSTEM
- PC platform(2 PIII 600 Mhz processors)
- F/A-18 Hornet flight stick and throttle
- Four Neuro Logic systems flat panel monitors
- Pacific Scientific servo motors and controllers
to implement force feedback - Smart-UPS 300 RM5U
- Microsoft flightsim 98 and Windows 98 SE
6NEW COMPONENTS PROVIDED BY SENIOR DESIGN 2000
TEAM
- Mechanical Flight Stick designed by ISM
- Designed to provide realistic flight feel
based on typical flight dynamics - Sola power supply rated 10 amperes at 12 volts.
- 5 volt logic power supply
- Two stepper motors Part M2-3437-S
- Group built stepper motor driver system with
gameport to USB conversions component.
7Existing System Block Diagram
8GROUP 9 SENIOR DESIGN 2000OBJECTIVES
- Create OPERATIONAL prototype
- Improve and upgrade flight operators controls
(ie. Flight stick, throttle, rudder) - Provide functional force feed back flight stick
resistance (real feel flight experience)
9SENIOR DESIGN 2001 ACCOMPLISHMENTS
- Improved Flight Operators Controls Gameport to
USB conversion - Functional Flight Stick Force Feedback
10FLIGHT CONTROL DEVICES OBJECTIVES
- RESTORE AND IMPROVE FUNCTIONALITY
- QUICK AND ACCURATE RESPONSE TIME
- DURABLE
- CAPABLE OF OPERATING UNDER HARSH CONDITIONS
- EASILY INTEGRATED INTO DTATS MISSION TRAINER
11Methods For Improving Flight Controls
- Redesign mechanical flight stick design
- Improved flight stick position sensing
- Conversion from gameport to USB device
12Mechanical Flight Stick Design
- Designed for us by ISM inc.
- Easily integrated into existing DTATS platform
- Accurately represent flight Dynamics
- Compatible with both our design for flight stick
force feedback and flight stick position sensing
methods
13Mechanical Flight Stick Design
14Mechanical Flight Stick Design
15Mechanical Flight Stick Design
16Flight Stick Position Sensing
17Flight Stick Position Sensing
- Potentiometers
- Hall Effect Sensors
- Optical position sensing
18Potentiometer Based Position Sensing
- Easily Integrated into new flight stick design
- Easily obtainable
- Low Cost
- Industrial grade with high resolution and linear
resistive output available
19USB Controls Interface
20Why USB?
Gameport
USB
- Limited Reliability
- Limited Speed
- Single device interface
- Specific single application
- Multi wire interface
- Much More Reliable
- Much Faster
- Can interface w/ up to 126 peripherals at once
- Can be used with any USB compatible device
- Simple 4 wire interface with only 2 data lines
21USB Cable at a Glance
22How Do We Do It?
- Flight stick axis potentiometers and buttons send
out information - Axis information is then sent through an RC
network to create a variable ? constant - The microcontroller systematically sends out one
shot pulses to read the ? of each axis - Cypress USB uC converts to serial USB protocol
- Windows recognizes device as an HID
23Flight Controls Block Diagram
RC
RC
RC
CY63000A Microcontroller
Flight Controls
CPU
RC
24USB Microcontroller Requirements
- Must have multiple ports (needs to support 4 axis
and at least 4 buttons) - Must have high enough resolution to support game
interface - Must automatically convert analog information
into serial USB protocol - Must be compatible with Windows HID protocol
25Cypress CY7C63000A
- Easy to use
- Development kit available from mfg.
- Commonly used in this type of application
- Cheap
- Reliable
- Stand alone does it all package
26Cypress CY7C63000A Cont
Image complements of Cypress.com
27Microcontroller pin-outs
Port 0 (Buttons)
Port 1 (Axiis)
USB Data
Image complements of Cypress.com
28Generating Force Feedback for the Flight Stick
29Real Feel Flight Experience
- The F/A-18 flight stick will resist move with 3.5
to 4.5 pounds of force per G. - Implemented using extension springs, redesigned
gimbal device, and stepper motors for varying the
extension of the springs.
30General Methodology for Implementing Force
Feedback
- Flight equations generated by the flight
simulation software will update the required
amount of force which needs to be applied to the
flight stick. - Stepper motors will be controlled via a printer
port (each of which has 8 output pins) in order
to rotate them in the correct direction which
cause the preloading spring mechanism to affect
the desired amount of force. - Insert picture of physical flight stick on next
slide.
31Choice of Motor Type for Actuation
- Servomotors were originally used. We replaced
these with Stepper motors for the following
reasons. - Easily integrated into software because of logic
encoded step commands. Simple physical operation
of stator and rotor. - The last design made use of a software program
for updating the motor characteristics which
could not be integrated with a flight simulator
program. - Cost The current stepper motors are
approximately 1/10th the cost of the original
servomotors. -
32Bipolar Stepper Motor
- Two motor windings are enclosed which cause
magnetic forces to attract the teeth of the
stator and rotor to each other. A logic 1 or 0
defines the direction of current across the
winding. - Disadvantage Open loop system if the torque
pulls the stator and rotor out of position, the
motor will rotate freely. However, if we operate
well within the holding torque range of the motor
this is not a problem.
33H Bridge Motor Control
- To facilitate the switching of current direction
across the motor winding, electronic drive
circuitry is needed. - The Allegro Microsystems 3952 was chosen as our
H-bridge IC.
- Conceptual drawing of H bridge.
- A, B, C, and D are switches that either conduct
current or cut the node off from the power supply
34Reasons for Choosing the Allegro 3952 H-bridge IC
- Logic gates incorporated into the IC select fast
decay, slow decay, or braking modes. - It can direct up to 3.5 amperes of peak current.
- Rated for up to 55 volts.
- Incorporates internal sense circuitry for current
detection. - Provides a simple platform for determining the
off time used in PWM current limiting. - Comes in a 16 pin DIP package for easy
breadboarding and transfer to circuit board.
35Current Utilization of the 3952 IC in DTATS Design
- Due to a physical redesign which reduced the
amount of torque required from the motor shaft,
we decided to use resistive current limiting
rather than PWM current limiting. - Currently, the H-bridge is required to switch 1.4
Amperes through each motor winding rather than 2
Amperes which was initially planned for. - Much of the logic is unnecessary for our
application. E.G., in the current design we see
no need to either brake or disable the H-bridge.
These inputs (brake and enable) are always tied
to logic high and low respectively.
36Stepping the motor
- By logically encoding the motor inputs we only
need a two bit output to step the motor through a
full rotation. - The printer port is being used to output the
correct number of encoded bits to serially step
the motor through the required rotations. - See next slide for details.
373952 Logic for Current Switching.
- The direction of current in the 3952 is
controlled by one signal called phase. - Phase high will cause current to flow from out
A to out B (Please refer to functional diagram)
38Step Sequence (continued)
- The figure on the right is a crude representation
of the previously described bipolar step motor. - It is connected to the outputs of two 3952 ICs.
- In the picture both IC1 and IC2 are receiving a
high value on their phase input pin. - Representing this as a two bit vector with IC1 as
the high bit and IC2 low bit we can see that the
following decimal sequence will cause a clockwise
rotation. - 3, 1, 0, 2. This shall be used in a step routine
on the PC.
39PC Step Routine in Software
- The Borland Turbo C compiler was used because
of abundant references found in literature
regarding the outport() function. - This function is found in the dos.h header file.
- The printer port is at address 378hex or 888
decimal. outport() will accept either form. The
function requires two arguments port address,
and value to write. - We could not take on the responsibility of
converting the Lockheed Martin flight simulator
software, so we have not incorporated this simple
functionality into the flight simulator program.
It is apparent how it can be used based on the
design methodology.
40Shortcomings of the Printer Port as Control
Signal Generator
- After the design was finalized it became apparent
that the printer port was experiencing problems
regarding the speed at which it could generate
output bits. - A possible remedy of the problem is to send basic
signals to a Basic Stamp or other microcontroller
from the printer port. Thus making the
microcontroller responsible for the high speed
loop output for motor stepping.
41Distribution of Work
42D.T.A.T.S. Milestones
Proposed
Actual
43Budget