File content as of revision 26:fe3a5469dd6b:

#include "mbed.h"
#include "HIDScope.h"
#include "MODSERIAL.h"
#include "biquadFilter.h"
#include "QEI.h"
#include "math.h"
#include <string> 

/*--------------------------------------------------------------------------------------------------------------------
-------------------------------- BIOROBOTICS GROUP 14 ----------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//Define important constants in memory
#define     PI              3.14159265
#define     SAMPLE_RATE     0.002   //500 Hz EMG sample rate
#define     CONTROL_RATE    0.01    //100 Hz Control rate
#define     ENCODER1_CPR    4200    //encoders have 64 (X4), 32 (X2) counts per revolution of motor shaft
#define     ENCODER2_CPR    4200    //gearbox 1:131.25 ->  4200 counts per revolution of the output shaft (X2), 
#define     PWM_PERIOD      0.0001  //10k Hz pwm motor frequency. Higher -> too hot, lower -> motor doesnt respond correctly
/*--------------------------------------------------------------------------------------------------------------------
---- OBJECTS ---------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

MODSERIAL pc(USBTX,USBRX);      //serial communication

//Debug legs
DigitalOut red(LED_RED);
DigitalOut green(LED_GREEN);
DigitalOut blue(LED_BLUE);

//EMG shields
AnalogIn    emg1(A0);           //Analog input - Biceps EMG
AnalogIn    emg2(A1);           //Analog input - Triceps EMG
AnalogIn    emg3(A2);           //Analog input - Flexor EMG
AnalogIn    emg4(A3);           //Analog input - Extensor EMG

Ticker      sample_timer;       //Ticker for EMG sampling
Ticker      control_timer;      //Ticker for control loop
HIDScope    scope(4);           //Scope 4 channels

// AnalogIn potmeter(A4);       //potmeters
// AnalogIn potmeter2(A5);      //

//Encoders 
QEI Encoder1(D13,D12,NC,32);    //channel A and B from encoder, counts = Encoder.getPulses();
QEI Encoder2(D10,D9,NC,32);     //channel A and B from encoder, 

//Speed and Direction of motors - D4 (dir) and D5(speed) = motor 2, D7(dir) and D6(speed) = motor 1
PwmOut pwm_motor1(D6);          //PWM motor 1
PwmOut pwm_motor2(D5);          //PWM motor 2

DigitalOut dir_motor1(D7);      //Direction motor 1
DigitalOut dir_motor2(D4);      //Direction motor 2

//Limit Switches
InterruptIn shoulder_limit(D3);  //using FRDM buttons 
InterruptIn elbow_limit(D4);     //using FRDM buttons

//Other buttons
DigitalIn button1(PTA4);        //using FRDM buttons 
DigitalIn button2(PTC6);        //using FRDM buttons

/*Text colors ASCII code: Set Attribute Mode    <ESC>[{attr1};...;{attrn}m

\ 0 3 3  - ESC 
[ 3 0 m  - black
[ 3 1 m  - red
[ 3 2 m  - green
[ 3 3 m  - yellow
[ 3 4 m  - blue
[ 3 5 m  - magenta
[ 3 6 m  - cyan
[ 3 7 m  - white 
[ 0 m    - reset attributes

Put the text you want to color between GREEN_ and _GREEN
*/
string GREEN_ = "\033[32m";    //esc - green
string _GREEN = "\033[0m";     //esc - reset 


/*--------------------------------------------------------------------------------------------------------------------
---- DECLARE VARIABLES -----------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//EMG variables: raw EMG - filtered EMG - maximum voluntary contraction
double emg_biceps; double biceps_power; double bicepsMVC = 0;
double emg_triceps; double triceps_power; double tricepsMVC = 0;
double emg_flexor; double flexor_power; double flexorMVC = 0;
double emg_extens; double extens_power; double extensMVC = 0;

int muscle;             //Muscle selector for MVC measurement
double calibrate_time;  //Elapsed time for each MVC measurement

//PID variables
double u1; double u2;                                               //Output of PID controller (PWM value for motor 1 and 2)
double m1_error=0; double m1_e_int=0; double m1_e_prev=0;           //Error, integrated error, previous error
const double m1_kp=0; const double m1_ki=0; const double m1_kd=0;   //Proportional, integral and derivative gains.

double m2_error=0; double m2_e_int=0; double m2_e_prev=0;           //Error, integrated error, previous error
const double m2_kp=0; const double m2_ki=0; const double m2_kd=0;   //Proportional, integral and derivative gains.

//highpass filter 20 Hz
const double high_b0 = 0.956543225556877;
const double high_b1 = -1.91308645113754;
const double high_b2 = 0.956543225556877;
const double high_a1 = -1.91197067426073;
const double high_a2 = 0.9149758348014341;
 
//notchfilter 50Hz
/*  ** Primary Filter (H1)**
Filter Arithmetic = Floating Point (Double Precision)
Architecture = IIR
Response = Bandstop
Method = Butterworth
Biquad = Yes
Stable = Yes
Sampling Frequency = 500Hz
Filter Order = 2

Band  Frequencies (Hz)    Att/Ripple (dB)       Biquad #1                                               Biquad #2

1     0, 48               0.001                 Gain = 1.000000                                         Gain = 0.973674
2     49, 51              -60.000               B = [ 1.00000000000, -1.61816176147,  1.00000000000]    B = [ 1.00000000000, -1.61816176147,  1.00000000000]
3     52, 250             0.001                 A = [ 1.00000000000, -1.58071559235,  0.97319685401]    A = [ 1.00000000000, -1.61244708381,  0.97415116257]
*/

//biquad 1
const double notch1gain = 1.000000;
const double notch1_b0 = 1;
const double notch1_b1 = -1.61816176147 * notch1gain;
const double notch1_b2 = 1.00000000000 * notch1gain;
const double notch1_a1 = -1.58071559235 * notch1gain;
const double notch1_a2 = 0.97319685401 * notch1gain;
 
//biquad 2
const double notch2gain = 0.973674;
const double notch2_b0 = 1 * notch2gain;
const double notch2_b1 = -1.61816176147 * notch2gain;
const double notch2_b2 = 1.00000000000 * notch2gain;
const double notch2_a1 = -1.61244708381 * notch2gain;
const double notch2_a2 = 0.97415116257 * notch2gain;
 
//lowpass filter 7 Hz  - envelope
const double low_b0 = 0.000119046743110057;
const double low_b1 = 0.000238093486220118;
const double low_b2 = 0.000119046743110057;
const double low_a1 = -1.968902268531908;
const double low_a2 = 0.9693784555043481;


/*--------------------------------------------------------------------------------------------------------------------
---- Filters ---------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//Using biquadFilter library
//Syntax: biquadFilter     filter(a1, a2, b0, b1, b2); coefficients. Call with: filter.step(u), with u signal to be filtered.
//Biceps
biquadFilter     highpass( high_a1 , high_a2 , high_b0 , high_b1 , high_b2 );               // removes DC and movement artefacts
biquadFilter     notch1( notch1_a1 , notch1_a2 , notch1_b0 , notch1_b1 , notch1_b2 );       // removes 49-51 Hz power interference
biquadFilter     notch2( notch2_a1 , notch2_a2 , notch2_b0 , notch2_b1 , notch2_b2 );       //
biquadFilter     lowpass( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 );                     // EMG envelope    

//Triceps
biquadFilter     highpass2( high_a1 , high_a2 , high_b0 , high_b1 , high_b2 );               // removes DC and movement artefacts
biquadFilter     notch1_2( notch1_a1 , notch1_a2 , notch1_b0 , notch1_b1 , notch1_b2 );      // removes 49-51 Hz power interference
biquadFilter     notch2_2( notch2_a1 , notch2_a2 , notch2_b0 , notch2_b1 , notch2_b2 );      //
biquadFilter     lowpass2( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 );                     // EMG envelope    

//Flexor
biquadFilter     highpass3( high_a1 , high_a2 , high_b0 , high_b1 , high_b2 );               // removes DC and movement artefacts
biquadFilter     notch1_3( notch1_a1 , notch1_a2 , notch1_b0 , notch1_b1 , notch1_b2 );      // removes 49-51 Hz power interference
biquadFilter     notch2_3( notch2_a1 , notch2_a2 , notch2_b0 , notch2_b1 , notch2_b2 );      //
biquadFilter     lowpass3( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 );                     // EMG envelope    

//Extensor
biquadFilter     highpass4( high_a1 , high_a2 , high_b0 , high_b1 , high_b2 );               // removes DC and movement artefacts
biquadFilter     notch1_4( notch1_a1 , notch1_a2 , notch1_b0 , notch1_b1 , notch1_b2 );      // removes 49-51 Hz power interference
biquadFilter     notch2_4( notch2_a1 , notch2_a2 , notch2_b0 , notch2_b1 , notch2_b2 );      //
biquadFilter     lowpass4( low_a1 , low_a2 , low_b0 , low_b1 , low_b2 );                     // EMG envelope    

//PID filter (lowpass ??? Hz)
biquadFilter     derfilter( 0.0009446914586925257 , 0.0018893829173850514 , 0.0009446914586925257 , -1.911196288237583 , 0.914975054072353 );   // derivative filter 

/*--------------------------------------------------------------------------------------------------------------------
---- DECLARE FUNCTION NAMES ------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

void sample_filter(void);   //Sampling and filtering
void control();             //Control - reference -> error -> pid -> motor output
void calibrate_emg();       //Instructions + measurement of MVC of each muscle 
void emg_mvc();             //Helper funcion for storing MVC value
void calibrate_arm(void);   //Calibration of the arm with limit switches
void start_sampling(void);  //Attaches the sample_filter function to a 500Hz ticker
void stop_sampling(void);   //Stops sample_filter
void start_control(void);   //Attaches the control function to a 100Hz ticker
void stop_control(void);    //Stops control function

//Keeps the input between min and max value
void keep_in_range(double * in, double min, double max);

//Reusable PID controller, previous and integral error need to be passed by reference
double pid(double error, double kp, double ki, double kd,double &e_int, double &e_prev);

//Menu functions
void mainMenu();
void caliMenu();
void clearTerminal();


/*--------------------------------------------------------------------------------------------------------------------
---- MAIN LOOP -------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

int main()
{
    pc.baud(115200);            //terminal baudrate
    red=1; green=1; blue=1;     //Make sure debug LEDS are off  
    
    //Set PwmOut frequency to 10k Hz
    pwm_motor1.period(PWM_PERIOD);    
    pwm_motor2.period(PWM_PERIOD);
    
    clearTerminal();            //Clear the putty window
    
    // make a menu, user has to initiate next step
    mainMenu();
    //caliMenu();            // Menu function
    //calibrate_arm();        //Start Calibration
    
    calibrate_emg();        
    
    //start_control();        //100 Hz control
    
    //maybe some stop commands when a button is pressed: detach from timers.
    //stop_control();
    //stop_sampling();
    
    while(1) {
           
    }
    //end of while loop
}
//end of main

/*--------------------------------------------------------------------------------------------------------------------
---- FUNCTIONS -------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------*/

//Sample and Filter  
void sample_filter(void)
{
    double emg_biceps = emg1.read();    //Biceps
    double emg_triceps = emg2.read();    //Triceps
    double emg_flexor = emg3.read();    //Flexor
    double emg_extens = emg4.read();    //Extensor
    
    //Filter: high-pass -> notch -> rectify -> lowpass or moving average
    // Can we use same biquadFilter (eg. highpass) for other muscles or does each muscle need its own biquad?
    biceps_power = highpass.step(emg_biceps); triceps_power = highpass2.step(emg_triceps); flexor_power = highpass3.step(emg_flexor); extens_power = highpass4.step(emg_extens);
    biceps_power = notch1.step(biceps_power); triceps_power = notch1_2.step(triceps_power); flexor_power = notch1_3.step(flexor_power); extens_power = notch1_4.step(extens_power);
    biceps_power = notch2.step(biceps_power); triceps_power = notch2_2.step(triceps_power); flexor_power = notch2_3.step(flexor_power); extens_power = notch2_4.step(extens_power);
    biceps_power = abs(biceps_power); triceps_power = abs(triceps_power); flexor_power = abs(flexor_power); extens_power = abs(extens_power);
    biceps_power = lowpass.step(biceps_power); triceps_power = lowpass2.step(triceps_power); flexor_power = lowpass3.step(flexor_power); extens_power = lowpass4.step(extens_power);
    
    
    /* alternative for lowpass filter: moving average
    window=30;                      //30 samples
    int i=0;                        //buffer index
    bicepsbuffer[i]=biceps_power    //fill array
    
    i++;                             
    if(i==window){
        i=0;
    }
    
    for(int x = 0; x < window; x++){
        avg1 += bicepsbuffer[x];
        }
    avg1 = avg1/window;    
    */
    
}

//Send arm to mechanical limits, and set encoder to 0. Then send arm to starting position.
void calibrate_arm(void)
{
    red=0; blue=0;              //Debug light is purple during arm calibration
    bool calibrating = true;
    bool done1 = false;
    bool done2 = false;
    dir_motor1=1;   //cw
    dir_motor2=1;   //cw
    pwm_motor1.write(0.2f);     //move upper arm slowly cw
    pwm_motor2.write(0.2f);     //move forearm slowly cw
    
    while(calibrating){
    
        //when limit switches are hit, stop motor and reset encoder
        if(shoulder_limit.read() < 0.5){   //polling 
            pwm_motor1.write(0);
            Encoder1.reset();
            done1 = true;
        }
        if(elbow_limit.read() < 0.5){     //polling
            pwm_motor2.write(0);
            Encoder2.reset();
            done2 = true;
        }    
        if(done1 && done2){
            calibrating=false;      //Leave while loop when both limits are reached
            red=1; blue=1;          //Turn debug light off when calibration complete
        }
    
    }//end while

}

//EMG Maximum Voluntary Contraction measurement
void emg_mvc()
{  
    //double sampletime=0;
    //sampletime=+SAMPLE_RATE;
    //
    // if(sampletime<5)
    //int muscle=1;
    //for(int index=0; index<2500;index++){   //measure 5 seconds@500hz = 2500 samples
     
        if(muscle==1){
            
            if(biceps_power>bicepsMVC){
            //printf("+ ");
            printf("%s+ %s",GREEN_,_GREEN);
            bicepsMVC=biceps_power;
            }    
            else
            printf("- ");
        }  
        
        if(muscle==2){
            
            if(triceps_power>tricepsMVC){
            printf("%s+ %s",GREEN_,_GREEN);
            tricepsMVC=triceps_power;
            }    
            else
            printf("- ");
        }
        
        if(muscle==3){
            
            if(flexor_power>flexorMVC){
            printf("%s+ %s",GREEN_,_GREEN);    
            flexorMVC=flexor_power;
            }    
            else
            printf("- ");
        }
        
        if(muscle==4){
            
            if(extens_power>extensMVC){
            printf("%s+ %s",GREEN_,_GREEN);    
            extensMVC=extens_power;
            }    
            else
            printf("- ");
        }
        
    //}
    calibrate_time = calibrate_time + 0.002;
    
    
   
}

//EMG calibration
void calibrate_emg()
{
   Ticker timer;
   
   pc.printf("Testcode calibration \r\n");
   wait(1);
   pc.printf("+ means current sample is higher than stored MVC\r\n");
   pc.printf("- means current sample is lower than stored MVC\r\n");
   wait(2);
   pc.printf(" Biceps is first. "); wait(1);
   pc.printf(" Press any key to begin... "); wait(1);
   char input;
   input=pc.getc();
   pc.putc(input);
   pc.printf(" \r\n  Starting in 3... \r\n"); wait(1);
   pc.printf(" \r\n  Starting in 2... \r\n"); wait(1);
   pc.printf(" \r\n  Starting in 1... \r\n"); wait(1);
   
   start_sampling();
   muscle=1;
   timer.attach(&emg_mvc,0.002);
   wait(5);
   timer.detach();
  
   pc.printf("\r\n Measurement complete."); wait(1);
   pc.printf("\r\n Biceps MVC = %f \r\n",bicepsMVC); wait(1);
      pc.printf("Calibrate_emg() exited \r\n"); wait(1);
   pc.printf("Measured time: %f seconds \r\n\n",calibrate_time);
   calibrate_time=0;
   
   // Triceps:
   muscle=2;
   pc.printf(" Triceps is next "); wait(1);
   pc.printf(" Press any key to begin... "); wait(1);
   input=pc.getc();
   pc.putc(input);
   pc.printf(" \r\n  Starting in 3... \r\n"); wait(1);
   pc.printf(" \r\n  Starting in 2... \r\n"); wait(1);
   pc.printf(" \r\n  Starting in 1... \r\n"); wait(1);
   start_sampling();
   muscle=1;
   timer.attach(&emg_mvc,0.002);
   wait(5);
   timer.detach();
   pc.printf("\r\n Triceps MVC = %f \r\n",tricepsMVC);
   
   pc.printf("Calibrate_emg() exited \r\n");
   pc.printf("Measured time: %f seconds \r\n",calibrate_time);
   calibrate_time=0;
   
   //Flexor:
   muscle=3;
   //Extensor:
   muscle=4;
   
   //Stop sampling, detach ticker
   stop_sampling();
   
}


//Input error and Kp, Kd, Ki, output control signal
double pid(double error, double kp, double ki, double kd,double &e_int, double &e_prev)
{
    // Derivative
    double e_der = (error-e_prev)/ CONTROL_RATE;
    e_der = derfilter.step(e_der);
    e_prev = error;
    // Integral
    e_int = e_int + CONTROL_RATE * error;
    // PID
    return kp*error + ki*e_int + kd * e_der;
 
}

//Analyze filtered EMG, calculate reference position from EMG, compare reference position with current position,convert to angles, send error through pid(), send PWM and DIR to motors 
void control()
{
    //analyze emg (= velocity, averages?)
    
    //calculate reference position based on the average emg (integrate)
    
    //calculate error (refpos-currentpos) currentpos = forward kinematics
    
    //inverse kinematics (pos error to angle error)
    
    //PID controller
    
    u1=pid(m1_error,m1_kp,m1_ki,m1_kd,m1_e_int,m1_e_prev);    //motor 1
    u2=pid(m2_error,m2_kp,m2_ki,m2_kd,m2_e_int,m2_e_prev);    //motor 2
    
    keep_in_range(&u1,-1,1);    //keep u between -1 and 1, sign = direction, PWM = 0-1
    keep_in_range(&u2,-1,1);
    
    //send PWM and DIR to motor 1
    dir_motor1 = u1>0 ? 1 : 0;          //conditional statement dir_motor1 = [condition] ? [if met 1] : [else 0]], same as if else below. 
    pwm_motor1.write(abs(u1));
    
    //send PWM and DIR to motor 2
    dir_motor2 = u2>0 ? 1 : 0;          //conditional statement, same as if else below
    pwm_motor2.write(abs(u2));
    
    /*if(u1 > 0)
    {
        dir_motor1 = 0;
    else{
        dir_motor1 = 1;
        }
    }    
    pwm_motor1.write(abs(u1));
    
  
    if(u2 > 0)
    {
        dir_motor1 = 1;
    else{
        dir_motor1 = 0;
        }
    }    
    pwm_motor1.write(abs(u2));*/
    
}

void mainMenu()
{
   //Title Box
   pc.putc(201); 
   for(int j=0;j<33;j++){
   pc.putc(205);
   }
   pc.putc(187); 
   pc.printf("\n\r");
   pc.putc(186); pc.printf("    BioRobotics M9 - Group 14    "); pc.putc(186);
   pc.printf("\n\r");
   pc.putc(186); pc.printf("         Robot powered ON        "); pc.putc(186);
   pc.printf("\n\r");
   pc.putc(200);
   for(int k=0;k<33;k++){
   pc.putc(205);
   }
   pc.putc(188); 
   
   pc.printf("\n\r");
   //endbox
}
void caliMenu(){};

//Start sampling
void start_sampling(void)
{
    sample_timer.attach(&sample_filter,SAMPLE_RATE);   //500 Hz EMG 
    
    //Debug LED will be green when sampling is active
    green=0;    
    pc.printf("||- started sampling -|| \r\n");
}

//stop sampling
void stop_sampling(void)
{
    sample_timer.detach();
    
    //Debug LED will be turned off when sampling stops
    green=1;
    pc.printf("||- stopped sampling -|| \r\n");
}

//Start control
void start_control(void)
{
    control_timer.attach(&control,SAMPLE_RATE);     //100 Hz control
    
    //Debug LED will be blue when control is on. If sampling and control are on -> blue + green = cyan.
    blue=0;
    pc.printf("||- started control -|| \r\n");
}

//stop control
void stop_control(void)
{
    control_timer.detach();
    
    //Debug LED will be off when control is off
    blue=1;
    pc.printf("||- stopped control -|| \r\n");
}


void calibrate()
{

}

//Clears the putty (or other terminal) window
void clearTerminal()
{
   pc.putc(27); 
   pc.printf("[2J"); // clear screen 
   pc.putc(27); // ESC 
   pc.printf("[H"); // cursor to home 
}

//keeps input limited between min max
void keep_in_range(double * in, double min, double max)
{
    *in > min ? *in < max? : *in = max: *in = min;
}