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/*
* DeltaParameters.cpp
*
* Created on: 20 Apr 2015
* Author: David
*/
#include "RepRapFirmware.h"
void DeltaParameters::Init()
{
deltaMode = false;
diagonal = 0.0;
radius = 0.0;
xCorrection = yCorrection = zCorrection = 0.0;
xTilt = yTilt = 0.0;
printRadius = defaultPrintRadius;
homedHeight = defaultDeltaHomedHeight;
for (size_t axis = 0; axis < DELTA_AXES; ++axis)
{
endstopAdjustments[axis] = 0.0;
towerX[axis] = towerY[axis] = 0.0;
}
}
void DeltaParameters::Recalc()
{
deltaMode = (radius > 0.0 && diagonal > radius);
if (deltaMode)
{
towerX[A_AXIS] = -(radius * cos((30 + xCorrection) * degreesToRadians));
towerY[A_AXIS] = -(radius * sin((30 + xCorrection) * degreesToRadians));
towerX[B_AXIS] = +(radius * cos((30 - yCorrection) * degreesToRadians));
towerY[B_AXIS] = -(radius * sin((30 - yCorrection) * degreesToRadians));
towerX[C_AXIS] = -(radius * sin(zCorrection * degreesToRadians));
towerY[C_AXIS] = +(radius * cos(zCorrection * degreesToRadians));
Xbc = towerX[C_AXIS] - towerX[B_AXIS];
Xca = towerX[A_AXIS] - towerX[C_AXIS];
Xab = towerX[B_AXIS] - towerX[A_AXIS];
Ybc = towerY[C_AXIS] - towerY[B_AXIS];
Yca = towerY[A_AXIS] - towerY[C_AXIS];
Yab = towerY[B_AXIS] - towerY[A_AXIS];
coreFa = fsquare(towerX[A_AXIS]) + fsquare(towerY[A_AXIS]);
coreFb = fsquare(towerX[B_AXIS]) + fsquare(towerY[B_AXIS]);
coreFc = fsquare(towerX[C_AXIS]) + fsquare(towerY[C_AXIS]);
Q = 2 * (Xca * Yab - Xab * Yca);
Q2 = fsquare(Q);
D2 = fsquare(diagonal);
// Calculate the base carriage height when the printer is homed, i.e. the carriages are at the endstops less the corrections
const float tempHeight = diagonal; // any sensible height will do here
float machinePos[DELTA_AXES];
InverseTransform(tempHeight, tempHeight, tempHeight, machinePos);
homedCarriageHeight = homedHeight + tempHeight - machinePos[Z_AXIS];
}
}
// Make the average of the endstop adjustments zero, without changing the individual homed carriage heights
void DeltaParameters::NormaliseEndstopAdjustments()
{
const float eav = (endstopAdjustments[A_AXIS] + endstopAdjustments[B_AXIS] + endstopAdjustments[C_AXIS])/3.0;
endstopAdjustments[A_AXIS] -= eav;
endstopAdjustments[B_AXIS] -= eav;
endstopAdjustments[C_AXIS] -= eav;
homedHeight += eav;
homedCarriageHeight += eav; // no need for a full recalc, this is sufficient
}
// Calculate the motor position for a single tower from a Cartesian coordinate.
float DeltaParameters::Transform(const float machinePos[DELTA_AXES], size_t axis) const
{
return sqrt(D2 - fsquare(machinePos[X_AXIS] - towerX[axis]) - fsquare(machinePos[Y_AXIS] - towerY[axis]))
+ machinePos[Z_AXIS]
+ (machinePos[X_AXIS] * xTilt)
+ (machinePos[Y_AXIS] * yTilt);
}
// Calculate the Cartesian coordinates from the motor coordinates.
void DeltaParameters::InverseTransform(float Ha, float Hb, float Hc, float machinePos[DELTA_AXES]) const
{
const float Fa = coreFa + fsquare(Ha);
const float Fb = coreFb + fsquare(Hb);
const float Fc = coreFc + fsquare(Hc);
// debugPrintf("Ha=%f Hb=%f Hc=%f Fa=%f Fb=%f Fc=%f Xbc=%f Xca=%f Xab=%f Ybc=%f Yca=%f Yab=%f\n",
// Ha, Hb, Hc, Fa, Fb, Fc, Xbc, Xca, Xab, Ybc, Yca, Yab);
// Setup PQRSU such that x = -(S - uz)/P, y = (P - Rz)/Q
const float P = (Xbc * Fa) + (Xca * Fb) + (Xab * Fc);
const float S = (Ybc * Fa) + (Yca * Fb) + (Yab * Fc);
const float R = 2 * ((Xbc * Ha) + (Xca * Hb) + (Xab * Hc));
const float U = 2 * ((Ybc * Ha) + (Yca * Hb) + (Yab * Hc));
// debugPrintf("P= %f R=%f S=%f U=%f Q=%f\n", P, R, S, U, Q);
const float R2 = fsquare(R), U2 = fsquare(U);
float A = U2 + R2 + Q2;
float minusHalfB = S * U + P * R + Ha * Q2 + towerX[A_AXIS] * U * Q - towerY[A_AXIS] * R * Q;
float C = fsquare(S + towerX[A_AXIS] * Q) + fsquare(P - towerY[A_AXIS] * Q) + (fsquare(Ha) - D2) * Q2;
// debugPrintf("A=%f minusHalfB=%f C=%f\n", A, minusHalfB, C);
float z = (minusHalfB - sqrtf(fsquare(minusHalfB) - A * C)) / A;
machinePos[X_AXIS] = (U * z - S) / Q;
machinePos[Y_AXIS] = (P - R * z) / Q;
machinePos[Z_AXIS] = z - ((machinePos[X_AXIS] * xTilt) + (machinePos[Y_AXIS] * yTilt));
}
// Compute the derivative of height with respect to a parameter at the specified motor endpoints.
// 'deriv' indicates the parameter as follows:
// 0, 1, 2 = X, Y, Z tower endstop adjustments
// 3 = delta radius
// 4 = X tower correction
// 5 = Y tower correction
// 6 = diagonal rod length
// 7, 8 = X tilt, Y tilt. We scale these by the printable radius to get sensible values in the range -1..1
floatc_t DeltaParameters::ComputeDerivative(unsigned int deriv, float ha, float hb, float hc)
{
const float perturb = 0.2; // perturbation amount in mm or degrees
DeltaParameters hiParams(*this), loParams(*this);
switch(deriv)
{
case 0:
case 1:
case 2:
// Endstop corrections
break;
case 3:
hiParams.radius += perturb;
loParams.radius -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 4:
hiParams.xCorrection += perturb;
loParams.xCorrection -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 5:
hiParams.yCorrection += perturb;
loParams.yCorrection -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 6:
hiParams.diagonal += perturb;
loParams.diagonal -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 7:
case 8:
// X and Y tilt
break;
}
float newPos[DELTA_AXES];
hiParams.InverseTransform((deriv == 0) ? ha + perturb : ha, (deriv == 1) ? hb + perturb : hb, (deriv == 2) ? hc + perturb : hc, newPos);
if (deriv == 7)
{
return -newPos[X_AXIS]/printRadius;
}
if (deriv == 8)
{
return -newPos[Y_AXIS]/printRadius;
}
const float zHi = newPos[Z_AXIS];
loParams.InverseTransform((deriv == 0) ? ha - perturb : ha, (deriv == 1) ? hb - perturb : hb, (deriv == 2) ? hc - perturb : hc, newPos);
const float zLo = newPos[Z_AXIS];
return ((floatc_t)zHi - (floatc_t)zLo)/(2 * perturb);
}
// Perform 3, 4, 6, 7, 8 or 9-factor adjustment.
// The input vector contains the following parameters in this order:
// X, Y and Z endstop adjustments
// Delta radius
// X tower position adjustment
// Y tower position adjustment
// Diagonal rod length adjustment - omitted if doing 8-factor calibration (remainder are moved down)
// X tilt adjustment
// Y tilt adjustment
void DeltaParameters::Adjust(size_t numFactors, const floatc_t v[])
{
const float oldCarriageHeightA = GetHomedCarriageHeight(A_AXIS); // save for later
// Update endstop adjustments
endstopAdjustments[A_AXIS] += v[0];
endstopAdjustments[B_AXIS] += v[1];
endstopAdjustments[C_AXIS] += v[2];
NormaliseEndstopAdjustments();
if (numFactors >= 4)
{
radius += v[3];
if (numFactors >= 6)
{
xCorrection += v[4];
yCorrection += v[5];
if (numFactors == 7 || numFactors == 9)
{
diagonal += v[6];
}
if (numFactors == 8)
{
xTilt += v[6]/printRadius;
yTilt += v[7]/printRadius;
}
else if (numFactors == 9)
{
xTilt += v[7]/printRadius;
yTilt += v[8]/printRadius;
}
}
Recalc();
}
// Adjusting the diagonal and the tower positions affects the homed carriage height.
// We need to adjust homedHeight to allow for this, to get the change that was requested in the endstop corrections.
const float heightError = GetHomedCarriageHeight(A_AXIS) - oldCarriageHeightA - v[0];
homedHeight -= heightError;
homedCarriageHeight -= heightError;
// Note: if we adjusted the X and Y tilts, and there are any endstop adjustments, then the homed position won't be exactly in the centre
// and changing the tilt will therefore affect the homed height. We ignore this for now. If it is ever significant, a second sutocalibration
// run will correct it.
}
void DeltaParameters::PrintParameters(StringRef& reply) const
{
reply.printf("Stops X%.3f Y%.3f Z%.3f height %.3f diagonal %.3f radius %.3f xcorr %.2f ycorr %.2f zcorr %.2f xtilt %.3f%% ytilt %.3f%%\n",
endstopAdjustments[A_AXIS], endstopAdjustments[B_AXIS], endstopAdjustments[C_AXIS], homedHeight, diagonal, radius,
xCorrection, yCorrection, zCorrection, xTilt * 100.0, yTilt * 100.0);
}
// End
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