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Vehicle control design

Discussion in 'Electronic Basics' started by [email protected], Nov 2, 2007.

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  1. Guest

    I want to design Motor speed controllers ( VFD) AC Drive 1-phase or 3-
    phase for battery operated vehicles for short-distance use.
    Anyone can help me ?
    write to me....
     
  2. BobG

    BobG Guest

    ======================================
    Get this app note from Atmel:
    AVR494: AC Induction Motor Control Using the constant V/f Principle
    and a Natural PWM Algorithm
     
  3. Tom2000

    Tom2000 Guest

    Here's a routine U wrote for a PIC 12F683 that implements a V/F
    controller.

    I haven't gotten the hardware working yet, so it's untested. (I've
    found that I have a lot to learn about HV switching...)

    It might give you an idea or two of where to begin.

    Good luck!

    Tom


    ===============================


    ;--------------------------------------------------------
    ;
    ; VF_Controller.asm
    ;
    ; Voltage-Frequency Converter
    ;
    ; PIC 12F683 firmware
    ; to drive my VF Controller Mk II circuit
    ;
    ; V1.00: tested OK with scope on breadboard.
    ; did not test it with the switching
    ; hardware yet.
    ;
    ; tjl Sep 20,2007
    ;
    ;--------------------------------------------------------
    ;
    ; This program implements a half-bridge voltage-frequency
    ; speed controller for small single phase shaded pole
    ; induction motors.
    ;
    ; Speed range is from approx 60 Hz to 20 Hz, with the
    ; voltage reduced by the following formula:
    ;
    ; motor V = design V * motor freq / design freq
    ;
    ; The wiper of a pot connected between +5v and ground
    ; is connected to physical pin 3. The pot setting
    ; determines the motor speed.
    ;
    ; Active low -> open outputs on physical pins 7 and 6
    ; drive the high side and low side half-H switches,
    ; respectively.
    ;
    ; A half-cycle sinewave is synthesized via PWM, and
    ; appears as an active high PWM signal on physical
    ; pin 5.
    ;
    ; Connect pins 7 and 6 to the cathodes of optoisolator
    ; LEDs, and the PWM pin paralleled to the anodes through
    ; a 330 ohm series resistor.
    ;
    ; Use the optoisolator transistors to drive a high side
    ; P-channel MOSFET and a low side N-channel MOSFET.
    ;
    ; Connect the motor between the junction of the two
    ; MOSFETs and neutral.
    ;
    ;--------------------------------------------------------
    ;
    ; Physical pin 3 (AN3) - Speed pot
    ; Physical pin 5 (CCP1) - PWM output
    ; Physical pin 6 (GP1) - Neg Switch (active low)
    ; Physical pin 7 (GP0) - Pos Switch (active low)
    ;
    ;--------------------------------------------------------
    ;
    ; 12F683 RAM:
    ; 96 bytes in bank0, 0x20-0x7f
    ; 32 bytes in bank1, 0xa0-0xbf
    ;
    ; Program memory:
    ; 2k 14-bit words, 0x000-0x7ff
    ;
    ; Data EEPROM:
    ; 256 bytes, accessed through DE decls or
    ; the four EExxx registers
    ;

    ;--------------------------------------------------------
    ;
    ; Config section
    ;
    ;--------------------------------------------------------

    list p=12F683
    #include <p12F683.inc>

    __CONFIG _FCMEN_ON & _IESO_OFF & _CP_OFF & _CPD_OFF &
    _BOD_OFF & _MCLRE_OFF & _WDT_OFF & _PWRTE_ON & _INTOSCIO


    ;--------------------------------------------------------
    ;
    ; Radix, Defines, and Constants
    ;
    ;--------------------------------------------------------

    radix dec

    errorlevel -302

    ; I/O

    #define PosSw 0
    #define NegSw 1
    #define PWMpin 2
    #define Pot 4

    ; constants

    #define Tmrbase 60 ; tune this for 60 Hz at
    ; max speed setting
    #define PWM_val 254 ; 7.8 kHz w/ 8 MHz clock
    ; and no prescaling


    ;--------------------------------------------------------
    ;
    ; Macro definitions
    ;
    ;--------------------------------------------------------

    bank0 macro
    bcf STATUS,RP0
    endm

    bank1 macro
    bsf STATUS,RP0
    endm

    ;--------------------------------------------------------
    ;
    ; Storage
    ;
    ;--------------------------------------------------------

    ; EEPROM table data

    org 0x2100

    SineTbl de 0,13,25,37,50,62,74,86
    de 98,109,120,131,142,152,162,171
    de 180,189,197,205,212,219,225,231
    de 236,240,244,247,250,252,254,255
    de 255,255,254,252,250,247,244,240
    de 236,231,225,219,212,205,197,189
    de 180,171,162,152,142,131,120,109
    de 98,86,74,62,50,37,25,13

    VoltTbl de 255,247,240,233,227,221,215,210
    de 205,200,195,191,186,182,178,174
    de 171,168,164,161,158,155,152,149
    de 147,144,142,139,137,135,133,131
    de 129,126,125,123,121,119,118,116
    de 114,113,111,110,108,107,106,104
    de 103,102,101,99,98,97,96,95
    de 94,92,92,90,90,89,88,87


    ; Un-init RAM

    cblock 0x20

    w_bup ; save W and STATUS from ISR
    stat_bup
    semaphore ; semaphore set by ISR when TMR0 times out
    rawspeed ; raw ADC speed pot measurement value
    speedval ; speed value to load into TMR0
    sineptr ; SineTbl pointer
    sineval ; from SineTbl
    voltval ; from VoltTbl
    pwmvalhi ; high byte of sine x volt mult
    pwmvallo ; low byte of sine x volt mult
    running
    temp0
    temp1
    temp2
    temp3

    endc


    ;--------------------------------------------------------
    ;
    ; Program code begins here
    ;
    ;--------------------------------------------------------

    org 0 ; processor reset vector

    goto main

    org 0x04 ; interrupt vector

    goto Int_Svc_Rtn


    ;--------------------------------------------------------
    ;
    ; Interrupt service routine
    ;
    ;--------------------------------------------------------

    Int_Svc_Rtn

    movwf w_bup ; save the W and STATUS regs
    movf STATUS,W
    movwf stat_bup

    btfss INTCON,T0IF ; TMR0 overflow?
    goto enableints ; no, just enable ints and
    return

    bcf INTCON,T0IF
    movf speedval,W ; reload the TMR0 preset
    movwf TMR0
    movlw 1
    movwf semaphore ; tell SendCycle that an
    ; int has occurred

    enableints

    movf stat_bup,W ; restore the W and STATUS
    ; regs
    movwf STATUS
    movf w_bup,W

    bsf INTCON,GIE ; enable system interrupts
    retfie


    ;--------------------------------------------------------
    ;
    ; Main program routine begins here
    ;
    ;--------------------------------------------------------

    main

    ; Disable system interrupts

    bcf INTCON,GIE

    ; set the internal oscillator to 8 MHz

    bank1
    movlw 0x71
    movwf OSCCON
    bank0

    ; init I/O & ADC

    movlw 0x07
    movwf CMCON0 ; 0,1,2 are digital I/O
    bank1
    movlw b'01011000' ; AN3 analog, others
    ; digital I/O, Fosc/16
    movwf ANSEL
    movlw b'00010011' ; Preset PosSw and NegSw as
    ; inputs
    movwf TRISIO
    bank0
    movlw b'00001101' ; AN3, left-justified,ADON
    movwf ADCON0
    bcf GPIO,PWMpin ; set PWM output low

    ; set up PWM

    call StartPWM

    ; begin

    clrf running ; force parm init at first
    ; GetSpeed call
    call Dly1Sec ; 1 sec pause to let HV pwr
    ; supply settle

    mainloop

    call GetSpeed
    call SetPosPhase
    call SendCycle
    call SetNegPhase
    call SendCycle

    goto mainloop




    ;--------------------------------------------------------
    ;
    ; Subroutines
    ;
    ;--------------------------------------------------------


    PWMcalc ; 8 x 8 unsigned mult of sineval
    ; x voltval
    ; result in pwmvalhi and
    ; pwmvallo
    ; modifies sineval,
    ; temp0,temp1,temp3

    bank0
    clrf pwmvalhi
    clrf pwmvallo
    movf voltval,W
    movwf temp0 ; holds low byte of shifted
    ; voltval
    clrf temp1 ; holds high byte of
    ; shifted voltval
    movlw 8
    movwf temp3 ; counter
    mult1 rrf sineval,F
    btfss STATUS,C
    goto mult2
    movf temp0,W
    addwf pwmvallo,F
    btfss STATUS,C
    goto mult3
    incf pwmvalhi,F
    mult3 movf temp1,W
    addwf pwmvalhi,F
    mult2 bcf STATUS,C
    rlf temp0,F
    rlf temp1,F
    decfsz temp3,F
    goto mult1
    return


    LoadPWM ; pwmvalhi to CCPR1L,
    ; pwmvallo<7:6> to CCP1CON<5:4>
    bank0
    bcf CCP1CON,5
    bcf CCP1CON,4
    btfsc pwmvallo,7
    bsf CCP1CON,5
    btfsc pwmvallo,6
    bsf CCP1CON,4
    movf pwmvalhi,W
    movwf CCPR1L
    return



    GetSpeed ; read speed pot setting, set
    ; delay,
    ; then set TMR0 and semaphore

    bsf ADCON0,1 ; start an ADC measurement
    btfss PIR1,ADIF ; wait for completion
    goto $-1
    bcf PIR1,ADIF

    movf ADRESH,W ; get the reading
    movwf temp0

    movf running,F ; running?
    btfss STATUS,Z
    goto gslp2 ; if not, force parm
    ; initialization

    movlw 1
    movwf running
    goto gslp1

    gslp2 subwf rawspeed,W ; exit if it speed pot
    ; setting has not changed
    btfsc STATUS,Z
    return

    gslp1 movf temp0,W ; save the new reading
    movwf rawspeed

    comf temp0,F ; subtract speed reading
    ; from 255...
    bcf STATUS,C ; ...and divide it by 4
    rrf temp0,F
    bcf STATUS,C
    rrf temp0,F ; temp0 contains 0 (max) to
    ; 63 (min)

    movlw VoltTbl ; calc addr of volt table
    addwf temp0,W
    call EERead
    movwf voltval

    bcf STATUS,C ; double the speed index
    rlf temp0,F
    movlw Tmrbase ; add speed factor to timer
    ; base value
    addwf temp0,W
    movwf speedval

    comf speedval,F ; subtract from 256 (255),
    ; save as TMR0
    ; preload value

    bcf INTCON,GIE ; disable interrupts
    movf TMR0,F ; write to TMR0
    bcf INTCON,T0IF
    bsf INTCON,T0IE
    clrf semaphore ; clear interrupt semaphore
    bsf INTCON,GIE ; enable interrupts

    return




    SendCycle ; set pwm from sine table and
    ; volts tbl,
    ; wait for interrupt, set next
    ; step's vals

    clrf sineptr

    sclp1 movf sineptr,W ; get sine value
    call EERead
    movwf sineval
    call PWMcalc ; calc PWM from sine & pre-
    ; calc'd volts val
    call LoadPWM ; set new PWM duty cycle

    movf semaphore,F ; wait for TMR0 interrupt
    btfsc STATUS,Z
    goto $-2
    clrf semaphore

    incf sineptr,F ; loop through the sine
    ; table
    movlw 64 ; (SineTbl size)
    subwf sineptr,W
    btfss STATUS,Z
    goto sclp1

    return

    EERead ; EEPROM read. Enter with addr
    ; in W,
    ; exit with data in W
    bank1
    movwf EEADR
    bsf EECON1,RD
    movf EEDAT,W
    bank0
    return



    SetPosPhase ; Open PWM path to Q1

    bank0
    bsf GPIO,NegSw
    bsf GPIO,PosSw
    bank1
    movlw b'0010010'
    movwf TRISIO
    bank0
    bcf GPIO,PosSw
    return



    SetNegPhase ; Open PWM path to Q2

    bank0
    bsf GPIO,PosSw
    bsf GPIO,NegSw
    bank1
    movlw b'0010001'
    movwf TRISIO
    bank0
    bcf GPIO,NegSw
    return



    StartPWM ; Set up and start PWM

    bank1
    bsf TRISIO,PWMpin ; Disable the PWM output
    ; pin

    movlw PWM_val ; Set the PWM period into
    ; TMR2
    movwf PR2
    bank0

    movlw b'00001100' ; Set CCP module for PWM
    ; mode
    movwf CP1CON

    movlw 0 ; Inital duty cycle = 0%
    movwf CCPR1L

    clrf T2CON ; Set TMR2 scalers for 1:1
    bsf T2CON,TMR2ON ; Start TMR2

    bcf PIR1,TMR2IF ; Clear TMR2's interrupt
    ; flag

    btfss PIR1,TMR2IF ; Wait for TMR2 overflow
    goto $-1
    bcf PIR1,TMR2IF

    bank1 ; Start PWM by setting the
    ; PWM pin
    bcf TRISIO,PWMpin ; as an output
    bank0

    return



    Dly1Sec ; 1 sec delay at 8 MHz
    movlw 7
    bank1
    movwf OPTION_REG ; set for 1:256 prescaling
    ; for TMR0
    bank0
    movlw 31
    movwf temp0
    dlylp clrf TMR0 ; TMR0: 254 ticks of 256
    ; instr cycles
    bcf INTCON,T0IF
    btfss INTCON,T0IF
    goto $-1
    decf temp0,F
    btfss STATUS,Z
    goto dlylp
    movlw 1
    bank1
    movwf OPTION_REG ; restore 1:4 prescaling
    ; for TMR0
    bank0
    return


    end
     
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