Diff: main.cpp

Revision:

0:3c99f1705565

Child:

1:ba63033da653

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Oct 31 11:25:32 2016 +0000
@@ -0,0 +1,344 @@
+#include "mbed.h"
+#include "HIDScope.h"
+#include "BiQuad.h"
+#include "MODSERIAL.h"
+#include "QEI.h"
+#include "FastPWM.h"
+
+// in gebruik: D(0(TX),1(RX),4(motor2dir),5(motor2pwm),6(motor1pwm),7(motor1dir),
+//8(pushbutton),9(servoPWM),10(encoder),11(encoder),12(encoder),13(encoder)) A(0,1,2)(emg)
+
+MODSERIAL pc(USBTX, USBRX);
+HIDScope scope(6); // the amount of scopes to send to the pc
+
+//Define objects
+
+//Define the EMG inputs
+AnalogIn    emg1( A0 );
+AnalogIn    emg2( A1 );
+AnalogIn    emg3( A2 );
+
+//Define motor outputs
+DigitalOut motor1dir(D7); //direction of motor 1, attach at m1, set to 0: cw
+FastPWM motor1(D6);     // speed of motor 1
+FastPWM motor2(D5);     //speed of motor 2
+DigitalOut motor2dir(D4);   //direction of motor 2, attach at m2, set to 0: ccw
+FastPWM servo(D9);   //servo pwm
+
+QEI Encoder1(D13,D12,NC,64,QEI::X4_ENCODING); //defining encoder
+QEI Encoder2(D11,D10,NC,64,QEI::X4_ENCODING); //defining encoder
+
+//Define the Tickers
+Ticker      pos_timer;                      // the timer which is used to print the position every second
+Ticker      sample_timer;                   // the timer which is used to decide when a sample needs to be taken
+Ticker      control;                        // Ticker for processing encoder input to motor output
+Ticker      servo_control;                          // Ticker for calling servo_control
+
+//Initialize all variables
+volatile bool sampletimer = false;          // go flag
+volatile bool controller_go=false;
+volatile bool servo_go=false;
+
+double threshold = 0.04;                    // the threshold which the emg signals need to surpass to do something
+double samplefreq=0.002;                    // every 0.002 sec a sample will be taken this is a frequency of 500 Hz
+double emg02;                               // the first emg signal
+double emg12;                               // the second emg signal
+double emg22;                               // the third emg signal
+double ref_x=0.0000;                        // the x reference position
+double ref_y=0.0000;                        // the y reference position
+double old_ref_x;                           // the old x reference
+double old_ref_y;                           // the old y reference
+double speed=0.00008;                       // the variable with which a speed is reached of 1cm/s
+double theta=0.0;                           // angle of the arm
+double radius=0.0;                          // radius of the arm
+
+const double minRadius=0.43;                 // minimum radius of arm
+const double maxRadius=0.62;                 // maximum radius of arm
+const double min_y=-0.26;                   // minimum height which the spatula can reach
+char key;                                   // variable to place the keyboard input
+
+double m1_pwm=0;    //variable for PWM control motor 1
+double m2_pwm=0;    //variable for PWM control motor 2
+
+const double m1_Kp = 35.16, m1_Ki = 108.8, m1_Kd = 2.84, m1_N = 100; // controller constants motor 1
+double m1_v1 = 0, m1_v2 = 0; // Memory variables
+const double m1_Ts = 0.01; // Controller sample time
+
+const double m2_Kp = 9.974, m2_Ki = 16.49, m2_Kd = 1.341, m2_N = 100; // controller constants motor 2
+double m2_v1 = 0, m2_v2 = 0; // Memory variables
+const double m2_Ts = 0.01; // Controller sample time
+
+const double pi=3.14159265359;
+const double res = 64.0/(1.0/131.25*2.0*pi);     // resolution on gearbox shaft per pulse
+const double V_max=9.0;                    // maximum voltage supplied by trafo
+const double pulleyRadius=0.0398/2.0;        // pulley radius
+
+double servo_pwm=0.0023; // duty cycle 1.5 ms 7.5%, min 0.5 ms 2.5%, max 2.5 ms 12.5%
+const double minTheta=-43.0/180.0*pi;        //minimum angle robot
+const double maxTheta=-32.0/180.0*pi;        // maximum angle to which the spatula can stabilise
+const double diffTheta=maxTheta-minTheta;  //difference between max and min angle of theta for stabilisation
+const double min_servo_pwm=0.00217;   // corresponds to angle of theta -32 degrees
+const double max_servo_pwm=0.0023;    // corresponds to angle of theta -43 degrees
+const double res_servo=max_servo_pwm-min_servo_pwm;  //resolution of servo pwm signal between min and max angle
+const double servo_Ts=0.02;
+bool z_push=false;
+
+//Define the needed Biquad chains
+BiQuadChain bqc11;
+BiQuadChain bqc13;
+BiQuadChain bqc21;
+BiQuadChain bqc23;
+BiQuadChain bqc31;
+BiQuadChain bqc33;
+
+//Define the BiQuads for the filter of the first emg signal
+//Notch filter
+BiQuad bq111(0.9795,   -1.5849,    0.9795,    1.0000,   -1.5849,    0.9589);
+BiQuad bq112(0.9833,   -1.5912,    0.9833,    1.0000,   -1.5793,    0.9787);
+BiQuad bq113(0.9957,   -1.6111,    0.9957,    1.0000,   -1.6224,    0.9798);
+//High pass filter
+//BiQuad bq121( 9.56543e-01, -1.91309e+00, 9.56543e-01, -1.91120e+00, 9.14976e-01 ); //Old biquad values
+BiQuad bq121( 0.8956,   -1.7911,    0.8956,    1.0000,   -1.7814,    0.7941);
+BiQuad bq122( 0.9192,   -1.8385,    0.9192,    1.0000,   -1.8319,    0.8450);
+BiQuad bq123( 0.9649,   -1.9298,    0.9649,    1.0000,   -1.9266,    0.9403);
+//Low pass filter
+BiQuad bq131( 3.91302e-05, 7.82604e-05, 3.91302e-05, -1.98223e+00, 9.82385e-01 );
+
+//Define the BiQuads for the filter of the second emg signal
+//Notch filter
+BiQuad bq211 = bq111;
+BiQuad bq212 = bq112;
+BiQuad bq213 = bq113;
+//High pass filter
+BiQuad bq221 = bq121;
+BiQuad bq222 = bq122;
+BiQuad bq223 = bq123;
+//Low pass filter
+BiQuad bq231 = bq131;
+
+//Define the BiQuads for the filter of the third emg signal
+//notch filter
+BiQuad bq311 = bq111;
+BiQuad bq312 = bq112;
+BiQuad bq313 = bq113;
+//High pass filter
+BiQuad bq321 = bq121;
+BiQuad bq323 = bq122;
+BiQuad bq322 = bq123;
+//low pass filter
+BiQuad bq331 = bq131;
+
+void sampleflag()
+{
+    if (sampletimer==true) {
+        // this if statement is used to see if the code takes too long before it is called again
+        pc.printf("rate too high error in sampleflag\n\r");
+    }
+    //This sets the go flag for when the function sample needs to be called
+    sampletimer=true;
+}
+
+void activate_controller()
+{
+    if (controller_go==true) {
+        // this if statement is used to see if the code takes too long before it is called again
+        pc.printf("rate too high error in activate_controller()\n\r");
+    }
+    controller_go=true;   //activate go flag
+}
+
+void activate_servo_control()
+{
+    if (servo_go==true) {
+        pc.printf("error servo");
+    }
+    servo_go=true;   //activate go flag
+}
+
+void sample()
+{
+    //This checks if a key is pressed and changes the variable key in the pressed key
+    if (pc.readable()==1) {
+        key=pc.getc();
+    }
+    //Read the emg signals and filter it
+
+    emg02=bqc13.step(fabs(bqc11.step(emg1.read())));    //filtered signal 0
+    emg12=bqc23.step(fabs(bqc21.step(emg2.read())));    //filtered signal 1
+    emg22=bqc33.step(fabs(bqc31.step(emg3.read())));    //filtered signal 2
+
+    //remember what the reference was
+    old_ref_x=ref_x;
+    old_ref_y=ref_y;
+    //look if the emg signals go over the threshold and change the reference accordingly
+    if (emg02>threshold&&emg12>threshold&&emg22>threshold || key=='d') {
+        ref_x=ref_x-speed;
+        ref_y=ref_y-speed;
+
+    } else if (emg02>threshold&&emg12>threshold || key == 'a' || key == 'z') {
+        ref_x=ref_x-speed;
+
+    } else if (emg02>threshold&&emg22>threshold || key == 's') {
+        ref_y=ref_y-speed;
+
+    } else if (emg12>threshold&&emg22>threshold || key == 'e' ) {
+        ref_x=ref_x+speed;
+        ref_y=ref_y+speed;
+
+    } else if (emg12>threshold || key == 'q' ) {
+        ref_x=ref_x+speed;
+
+    } else if (emg22>threshold || key == 'w') {
+        ref_y=ref_y+speed;
+    }
+
+    if (key != 'z' && z_push) {
+        ref_x=0.0;
+        ref_y=0.0;
+        Encoder1.reset();
+        Encoder2.reset();
+        z_push=false;
+    }
+
+    // convert the x and y reference to the theta and radius reference
+    theta=atan(ref_y/(ref_x+minRadius));
+    radius=sqrt(pow(ref_x+minRadius,2)+pow(ref_y,2));
+
+    //look if the new reference is outside the possible range and revert back to the old reference if it is outside  the range
+    if (radius < minRadius) {
+        if (key != 'z') {
+            ref_x=old_ref_x;
+            ref_y=old_ref_y;
+        } else if (key == 'z') {
+            z_push=true;
+        }
+    } else if ( radius > maxRadius) {
+        ref_x=old_ref_x;
+        ref_y=old_ref_y;
+    } else if (ref_y<min_y) {
+        ref_y=old_ref_y;
+    }
+    theta=atan(ref_y/(ref_x+minRadius));
+    radius=sqrt(pow(ref_x+minRadius,2)+pow(ref_y,2));
+}
+
+double PID( double err, const double Kp, const double Ki, const double Kd,
+            const double Ts, const double N, double &v1, double &v2 )   //discrete PIDF filter
+{
+    const double a1 =-4/(N*Ts+2),
+                 a2=-(N*Ts-2)/(N*Ts+2),
+                 b0=(4*Kp + 4*Kd*N + 2*Ki*Ts+2*Kp*N*Ts+Ki*N*pow(Ts,2))/(2*N*Ts+4),
+                 b1=(Ki*N*pow(Ts,2)-4*Kp-4*Kd*N)/(N*Ts+2),
+                 b2=(4*Kp+4*Kd*N-2*Ki*Ts-2*Kp*N*Ts+Ki*N*pow(Ts,2))/(2*N*Ts+4);
+
+    double v=err-a1*v1-a2*v2;
+    double u=b0*v+b1*v1+b2*v2;
+    v2=v1;
+    v1=v;
+    return u;
+}
+
+void controller()  //function for executing controller action
+{
+
+    //converting radius and theta to gearbox angle
+    double ref_angle1=16*theta;
+    double ref_angle2=(-radius+minRadius)/pulleyRadius;
+
+    double angle1 = Encoder1.getPulses()/res;   //get number of pulses (counterclockwise is positive)
+    double angle2 = Encoder2.getPulses()/res;   //get number of pulses
+    m1_pwm = (PID(ref_angle1-angle1,m1_Kp,m1_Ki,m1_Kd,m1_Ts,m1_N,m1_v1,m1_v2))/V_max;
+    //divide by voltage to get pwm duty cycle percentage)
+    m2_pwm = (PID(ref_angle2-angle2,m2_Kp,m2_Ki,m2_Kd,m2_Ts,m2_N,m2_v1,m2_v2))/V_max;
+
+    //limit pwm value and change motor direction when pwm becomes either negative or positive
+    if (m1_pwm >=0.0f && m1_pwm <=1.0f) {
+        motor1dir=0;
+        motor1.write(m1_pwm);
+    } else if (m1_pwm < 0.0f && m1_pwm >= -1.0f) {
+        motor1dir=1;
+        motor1.write(-m1_pwm);
+    }
+
+    if (m2_pwm >=0.0f && m2_pwm <=1.0f) {
+        motor2dir=0;
+        motor2.write(m2_pwm);
+    } else if (m2_pwm < 0.0f && m2_pwm >= -1.0f) {
+        motor2dir=1;
+        motor2.write(-m2_pwm);
+    }
+
+    //hidsopce to check what the code does exactly
+    scope.set(0,ref_angle1-angle1); //error
+    scope.set(1,ref_angle1);
+    scope.set(2,m1_pwm);
+    scope.set(3,ref_angle2-angle2);
+    scope.set(4,ref_angle2);
+    scope.set(5,servo_pwm);
+    scope.send();
+}
+
+void servo_controller()
+{
+    if (theta < maxTheta ) {
+        servo_pwm=min_servo_pwm+(theta-minTheta)/diffTheta*res_servo;
+    } else {
+        servo_pwm=max_servo_pwm;
+    }
+
+    servo.pulsewidth(servo_pwm);
+
+}
+
+
+void my_pos()
+{
+    //This function is attached to a ticker so that the reference position is printed every second.
+    pc.printf("x_pos=%.4f\ty_pos=%.4f\tradius=%.4f\tangle=%.4f\n\r",ref_x,ref_y,radius,theta);
+
+}
+
+int main()
+{
+    pc.printf("RESET\n\r");
+    pc.baud(115200);
+
+    //Attach the Biquads to the Biquad chains
+    bqc11.add( &bq111 ).add( &bq112 ).add( &bq113 ).add( &bq121 ).add( &bq122 ).add( &bq123 );
+    bqc13.add( &bq131);
+    bqc21.add( &bq211 ).add( &bq212 ).add( &bq213 ).add( &bq221 ).add( &bq222 ).add( &bq223 );
+    bqc23.add( &bq231);
+    bqc31.add( &bq311 ).add( &bq312 ).add( &bq313 ).add( &bq321 ).add( &bq322 ).add( &bq323 );
+    bqc33.add( &bq331);
+
+    motor1.period(0.02f); //period of pwm signal for motor 1
+    motor2.period(0.02f); // period of pwm signal for motor 2
+    motor1dir=0; // setting direction to ccw
+    motor2dir=0; // setting direction to ccw
+
+    //Attach the 'sample' function to the timer 'sample_timer'.
+    //this ensures that 'sample' is executed every 0.002 seconds = 500 Hz
+    sample_timer.attach(&sampleflag, samplefreq);
+
+    //Attach the function my_pos to the timer pos_timer.
+    //This ensures that the position is printed every second.
+    pos_timer.attach(&my_pos, 1);
+    control.attach(&activate_controller,m1_Ts); //Ticker for processing encoder input
+    servo_control.attach(&activate_servo_control,servo_Ts);
+
+    while(1) {
+        //Only take a sample when the go flag is true.
+        if (sampletimer==true) {
+            sample();
+            sampletimer = false;            //change sampletimer to false if sample() is finished
+        }
+        if(controller_go) { // go flag
+            controller();
+            controller_go=false;
+        }
+        if(servo_go) {
+            servo_controller();
+            servo_go=false;
+        }
+    }
+}
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