File content as of revision 18:8806d24809c2:

#include "mbed.h"
#include "RobotLeg.h"
#include "Matrix.h"
#include "CircularBuffer.h"
#include "Radio.h"
#include "Terminal.h"
#include "utility.h"
#include <cstring>
#include <cmath>

#define MAXSPEED 0.1f
#define MAXTURN 1.0f
#define RESET_STEP_TIME 0.4f
#define DIM_A 0.125f
#define DIM_B 0.11f
#define DIM_C 0.0025f
#define DIM_D 0.0275f
#define CIRCLE_X 0.095f
#define CIRCLE_Y 0.095f
#define CIRCLE_Z -0.12f
#define CIRCLE_R 0.09f
#define PERIOD 0.002f



CircularBuffer<float,16> dataLog;
Radio radio(p5, p6, p7, p16, p17, p18);
RobotLeg legA(p26, p29, p30, false);
RobotLeg legB(p13, p14, p15, false);
RobotLeg legC(p19, p11, p8, false);
RobotLeg legD(p25, p24, p23, false);

DigitalOut led1(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
DigitalOut led4(LED4);



CmdHandler* legpos(Terminal* terminal, const char*)
{
    char output[256];
    char abuf[64];
    char bbuf[64];
    char cbuf[64];
    char dbuf[64];
    legA.getPosition().print(abuf, 64);
    legB.getPosition().print(bbuf, 64);
    legC.getPosition().print(cbuf, 64);
    legD.getPosition().print(dbuf, 64);
    snprintf(output, 256, "A = [%s]\nB = [%s]\nC = [%s]\nD = [%s]", abuf, bbuf, cbuf, dbuf);
    terminal->write(output);
    return NULL;
}



CmdHandler* log(Terminal* terminal, const char* input)
{
    int start = 0;
    int end = 15;
    char output[256];
    
    if (sscanf(input, "log %d %d", &start, &end) == 1)
    {
        // Print only one item
        snprintf(output, 256, "%4d: %f\n", start, dataLog[start]);
        terminal->write(output);
    }
    else
    {
        // Print a range of items
        for (int i = start; i <= end; i++)
        {
            snprintf(output, 256, "%4d: %f\n", i, dataLog[i]);
            terminal->write(output);
        }
    }  
    
    return NULL;
} // log()



void setupLegs();
float calcStability(vector3 p1, vector3 p2);

int counter; //debug

int main()
{
    Timer deltaTimer;
    float xaxis, yaxis, turnaxis, angle;
    float deltaTime;
    vector3 v;
    matrix4 T;
    matrix4 PA, QA;
    matrix4 PB, QB; 
    matrix4 PC, QC; 
    matrix4 PD, QD;
    Terminal terminal;
    
    terminal.addCommand("log", &log);
    terminal.addCommand("leg", &legpos);
    
    radio.reset();
    
    setupLegs();
    
    // Create matrices to change base from robot coordinates to leg coordinates
    QA.translate(vector3(0.0508f, 0.0508f, 0.0f));
    PA = QA.inverse();
    QB.translate(vector3(-0.0508f, -0.0508f, 0.0f));
    QB.a11 = -1.0f; QB.a22 = -1.0f;
    PB = QB.inverse();
    QC.translate(vector3(-0.0508f, 0.0508f, 0.0f));
    QC.a11 = -1.0f;
    PC = QC.inverse();
    QD.translate(vector3(0.0508f, -0.0508f, 0.0f));
    QD.a22 = -1.0f;
    PD = QD.inverse();
    
    // Start timer
    deltaTimer.start();
    
    while(true)
    {
        while (deltaTimer.read() < PERIOD);
        
        // Read controller input
        xaxis = 0.0078125f * deadzone((int8_t)((radio.rx_controller>>0)&0xff), 8); // Convert to +/-1.0f range
        yaxis = -0.0078125f * deadzone((int8_t)((radio.rx_controller>>8)&0xff), 8);
        turnaxis = -0.0078125f * deadzone((int8_t)((radio.rx_controller>>16)&0xff), 8);
        
        // Get delta-time
        deltaTime = deltaTimer.read();
        
        if ((radio.rx_controller>>25)&0x1) // reset
        {
            legA.reset(-0.6f);
            while (legA.getStepping()) legA.update(T);
            legB.reset(-0.1f);
            while (legB.getStepping()) legB.update(T);
            legC.reset(0.4f);
            while (legC.getStepping()) legC.update(T);
            legD.reset(0.9f);
            while (legD.getStepping()) legD.update(T);
        }
        
        deltaTimer.reset();
        //dataLog.push(deltaTime);
        
        // Compute delta movement vector and delta angle
        v.x = -xaxis;
        v.y = -yaxis;
        v.z = 0.0f;
        v = v * MAXSPEED * deltaTime;
        angle = -turnaxis * MAXTURN * deltaTime;
        
        // Compute movement transformation in robot coordinates
        T.identity().rotateZ(angle).translate(v).inverse();
        
        bool freeA = legA.update(PA*T*QA);
        bool freeB = legB.update(PB*T*QB);
        bool freeC = legC.update(PC*T*QC);
        bool freeD = legD.update(PD*T*QD);
        
        // Predict unstable step events and step early in response
        float distA = legA.getStepDistance();
        float distB = legB.getStepDistance();
        float distC = legC.getStepDistance();
        float distD = legD.getStepDistance();
        
        int leastIndex = least(distA, distB, distC, distD);
        float stability;
        vector3 point1, point2;
        const float margin = 0.015f; // radius of support base in meters
        
        switch(leastIndex)
        {
        case 0:
            point1 = QC*legC.getPosition();
            point2 = QD*legD.getPosition();
            break;
        case 1:
            point1 = QD*legD.getPosition();
            point2 = QC*legC.getPosition();
            break;
        case 2:
            point1 = QB*legB.getPosition();
            point2 = QA*legA.getPosition();
            break;
        case 3:
            point1 = QA*legA.getPosition();
            point2 = QB*legB.getPosition();
            break;
        }
        
        
        
        stability = calcStability(point1, point2);
        bool stepEarly = stability < margin && stability > 0.0f;
        
        // debug stuff
        if ((counter++%50)==0)
        {
            char buf[256];
            char vbuf[64];
            char vbuf2[64];
            point1.print(vbuf, 64);
            point2.print(vbuf2, 64);
            snprintf(buf, 256, "n = %d; p1 = %s; p1 = %s; s = %f\n", leastIndex, vbuf, vbuf2, stability); 
            terminal.write(buf);
        }
        
        if (stability < 0.0f)
        {
            // Move towards stable zone
            vector3 n;
            n.x = point2.y - point1.y;
            n.y = point1.x - point2.x;
            n = n.unit() * MAXSPEED * deltaTime;
            T.identity().translate(v).inverse();
        }
        
        // Debug info
        dataLog.push(stability);
        led1 = calcStability(QC*legC.getPosition(), QD*legD.getPosition()) > 0.0f;
        led2 = calcStability(QD*legD.getPosition(), QC*legC.getPosition()) > 0.0f;
        led3 = calcStability(QB*legB.getPosition(), QA*legA.getPosition()) > 0.0f;
        led4 = calcStability(QA*legA.getPosition(), QB*legB.getPosition()) > 0.0f;
        
        // Prevent multiple legs from stepping at the same time
        bool stepping = legA.getStepping() || legB.getStepping() || legC.getStepping() || legD.getStepping();
        bool lockup = false;
        
        if (!freeA || (0 == leastIndex && stepEarly))
        {
            if (stepping) lockup = true;
            else 
            {
                legA.reset(0.8);
                stepping = true;
            }
        }
        if (!freeB || (1 == leastIndex && stepEarly))
        {
            if (stepping) lockup = true;
            else 
            {
                legB.reset(0.8f);
                stepping = true;
            }
        }
        if (!freeC || (2 == leastIndex && stepEarly))
        {
            if (stepping) lockup = true;
            else 
            {
                legC.reset(0.8f);
                stepping = true;
            }
        }
        if (!freeD || (3 == leastIndex && stepEarly))
        {
            if (stepping) lockup = true;
            else 
            {
                legD.reset(0.8f);
                stepping = true;
            }
        }
        
        if (!lockup)
        {
            legA.apply();
            legB.apply();
            legC.apply();
            legD.apply();
        }
    } // while (true)
} // main()



void setupLegs()
{
    // Set leg parameters
    legA.setDimensions(DIM_A, DIM_B, DIM_C, DIM_D);
    legB.setDimensions(DIM_A, DIM_B, DIM_C, DIM_D);
    legC.setDimensions(DIM_A, DIM_B, DIM_C, DIM_D);
    legD.setDimensions(DIM_A, DIM_B, DIM_C, DIM_D);
    legA.setAngleOffsets(0.7853982f, 0.0f, 0.0f);
    legB.setAngleOffsets(0.7853982f, 0.0f, 0.0f);
    legC.setAngleOffsets(0.7853982f, 0.0f, 0.0f);
    legD.setAngleOffsets(0.7853982f, 0.0f, 0.0f);
    legA.setStepCircle(CIRCLE_X, CIRCLE_Y, CIRCLE_Z, CIRCLE_R);
    legB.setStepCircle(CIRCLE_X, CIRCLE_Y, CIRCLE_Z, CIRCLE_R);
    legC.setStepCircle(CIRCLE_X, CIRCLE_Y, CIRCLE_Z, CIRCLE_R);
    legD.setStepCircle(CIRCLE_X, CIRCLE_Y, CIRCLE_Z, CIRCLE_R);
    legA.theta.calibrate(1130, 2080, 45.0f, -45.0f);
    legA.phi.calibrate(1150, 2080, 70.0f, -45.0f);
    legA.psi.calibrate(1985, 1055, 70.0f, -60.0f);
    legB.theta.calibrate(990, 1940, 45.0f, -45.0f);
    legB.phi.calibrate(1105, 2055, 70.0f, -45.0f);
    legB.psi.calibrate(2090, 1150, 70.0f, -60.0f);
    legC.theta.calibrate(1930, 860, 45.0f, -45.0f);
    legC.phi.calibrate(1945, 1000, 70.0f, -45.0f);
    legC.psi.calibrate(1085, 2005, 70.0f, -60.0f);
    legD.theta.calibrate(2020, 1080, 45.0f, -45.0f);
    legD.phi.calibrate(2085, 1145, 70.0f, -45.0f);
    legD.psi.calibrate(1070, 2010, 70.0f, -60.0f);
    
    // Initialize leg position deltas
    legA.nDeltaPosition = vector3(0.0f, 0.01f, 0.0f);
    legB.nDeltaPosition = vector3(0.0f, -0.01f, 0.0f);
    legC.nDeltaPosition = vector3(0.0f, 0.01f, 0.0f);
    legD.nDeltaPosition = vector3(0.0f, -0.01f, 0.0f);
    
    // Go to initial position
    legA.move(vector3(0.15f, 0.15f, 0.05f));
    legB.move(vector3(0.15f, 0.15f, 0.05f));
    legC.move(vector3(0.15f, 0.15f, 0.05f));
    legD.move(vector3(0.15f, 0.15f, 0.05f));
    legA.theta.enable(); wait(0.1f);
    legB.theta.enable(); wait(0.1f);
    legC.theta.enable(); wait(0.1f);
    legD.theta.enable(); wait(0.1f);
    legA.phi.enable(); wait(0.1f);
    legB.phi.enable(); wait(0.1f);
    legC.phi.enable(); wait(0.1f);
    legD.phi.enable(); wait(0.1f);
    legA.psi.enable(); wait(0.1f);
    legB.psi.enable(); wait(0.1f);
    legC.psi.enable(); wait(0.1f);
    legD.psi.enable(); wait(0.1f);
    wait(0.4f);
    legA.reset(-0.6f);
    legB.reset(-0.1f);
    legC.reset(0.4f);
    legD.reset(0.9f);
}



float calcStability(vector3 p1, vector3 p2)
{
    float lx, ly, vx, vy;
    lx = p2.x - p1.x;
    ly = p2.y - p1.y;
    vx = -p1.x;
    vy = -p1.y;
    
    return (ly*vx - lx*vy)/sqrt(lx*lx + ly*ly);
}