Download Active Suspension System Test Platform Bradley University

Active Suspension System Test
Platform
Bradley University
Department of
Electrical & Computer Engineering
By:
Craig Chan & Olusegun Michael Abidoye
Advisor:
Steven Gutschlag
27 April 2005
Outline
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Project Summary
Division of Labor
Functional Description
Block Diagrams
Subsystems
Test Results
Parts List
Questions?
Project Summary
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Providing a test platform for active/passive
suspension system
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Testing vehicle suspension system
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Actuator driven and micro-controller based
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Common feedback control applications
CNC fabrication machines
 Aviation control
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Division of Labor
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Craig
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Design and build power electronics to drive a 115 Volt
DC motor
Microcontroller isolation circuitry
 H-Bridge design
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Control algorithm
 Testing and debugging
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Mike
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Microcontroller based feedback control system
Control Algorithm
 A/D converter
 PWM (Timer 2)
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Testing and debugging
Functional Description
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Microcontroller feedback system ensures proper output
independent of load.
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The mode of operation will be determined by the user
via a keypad on the micro-controller.
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Sinusoidal
Step
Triangular
Flexibility in selecting desired speed and travel distance
of the platform
Overall Control Block Diagram
Pe
Pi
Pa
Perror = Pinput – Pactuator
Output
(Platform Position)
System Block Diagram
Analog Position
Input
Keypad Input
(Desired Platform
Motion)
A/D
Converter
EMAC Micropac 535
Micro-Controller
Interface
POSITION
FEEDBACK
Display
( user input)
Power
Electronics
Test
Platform
Output
(Platform
Motion)
Hardware Subsystem
Hardware Configuration
Power MOSFETS
4N25
Phototransistor Optocouplers
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Infrared emitting diode driving a phototransistor
Provides voltage isolation between the
microcontroller and the IR2213
IR640N
Power MOSFET’s
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Drain to Source Voltage Max = 200 Volts
Continuous Drain Current Max = 18A
IR2213
High & Low Side Driver
Configuration
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Load supply voltage up to +1200 volts
N-Channel MOSFETs (Faster & Cheaper)
IR2213
High & Low Side Driver
Decoupling
Capacitors
Charge Pump
Bootstrap Circuit
Decoupling
Capacitor
H-Bridge
IR 2213
IR 2213
Vcc
(Signal to
MOSFETs)
A
(Signal to
MOSFETs)
B
ON
ON
ON
ON
C
Gnd
D
Software Subsystem
Setup Module
 Initializes
the microcontroller
 Setups interrupt vector tables
 Setups necessary peripherals
 Configures interrupt priority
 Jumps to main module
Main Module
 Welcomes
the user
 Prompts the user platform
parameters
 Amplitude
and frequency
 Waveform (single or continuous)
Keypad Module
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EX1 interrupt handler
Fetches keys pressed via kpad subroutine
 Translates keys to ASCII equivalent
 Performs necessary task for each key
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Key A = Single Step input
 Key B = Backspace
 Key C = Continuous waveform input
 Key D = Stop suspension
 Key E = Start suspension
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Lcd Module
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Displays prompts
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Displays user’s entries
Timer 2 Module
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Configuration
Auto reload , mode 0
 Compare mode 1 (16 bits)
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Subroutines
PWM Subroutine
 Timer 2 interrupt handler
 EX4 interrupt handler (when T2 register = CC1)
 EX5 interrupt handler (when T2 register = CC2)
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PWM Subroutine
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Generates two PWM signals at P4.1 and P4.2
Decides which one to turn on, via direction flag
Generates three interrupts
T2 interrupt (overflow)
 CC1 = T2  EX4 interrupt
 CC2 = T2  EX5 interrupt
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PWM Subroutine
•Checking direction flag
•Forward Pwm
•Reverse Pwm
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Timer 2 interrupt
handler
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EX4 interrupt handler
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Forward PWM
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EX5 interrupt handler
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Reverse PWM
A/D Module
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Determines status of direction flag
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A/D_pi
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Fetches input signal from AN0
A/D_pa
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Fetches position feedback from AN2
Control Block Diagram
Input Voltage Signal
Representing the Desired
Platform Motion
(Provided by the
Waveform Generator)
Gain
Old Duty
Cycle
Output
(Platform Motion)
Suspension Module
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DC_new = DC_old + K * Pe
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Pe = Pi – Pa
(Pi > Pa, clr dir flag, forward PWM)
DC_new = DC_old – K *Pe
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Pe = Pa – Pi
(Pa > Pi, setb dir flag, reverse PWM)
Test Platform Subsystem
Rated DC Motor Specifications
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RPM Max 1725
Horse Power 1/3
Volts 115
Amps 3.4
Screw Jack Specifications
(Nook Industries)
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18 Inches of Stroke Length
Gear Ratio 5:1
Turns of worm per inch travel = 10
Max Horse Power 1/3
Max load = 1000 Lbs
Max worm speed at rated load = 868 RPM
Max load at 1750 RPM = 496 lbs
Assembled with a top plate
Inch Ball Screw Jack
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Without Top Plate
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With Top Plate
Preliminary Experimental Results
Electrak mini actuator
Pi = Input signal
Pa = Actuator Position
Sinusoidal Input
Pi = Input signal
Pa = Actuator Position
Triangular Input
Pi = Input signal
Pa = Actuator Position
Parts List
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Micro Pac 535 (EMAC Kit # 5)
High and Low Side Driver (IR2213)
Phototransistor (4N25)
N-channel Power MOSFETS (IR640)
Electrak mini actuator
Screw Jack (0.5HL-BSJU)
DC Motor (437698-AW)
QUESTIONS
?