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|
/*
* DeltaParameters.cpp
*
* Created on: 20 Apr 2015
* Author: David
*/
#include "LinearDeltaKinematics.h"
#if SUPPORT_LINEAR_DELTA
#include <Movement/Move.h>
#include <Platform/RepRap.h>
#include <Storage/FileStore.h>
#include <GCodes/GCodeBuffer/GCodeBuffer.h>
#include <Math/Deviation.h>
#if SUPPORT_OBJECT_MODEL
// Object model table and functions
// Note: if using GCC version 7.3.1 20180622 and lambda functions are used in this table, you must compile this file with option -std=gnu++17.
// Otherwise the table will be allocated in RAM instead of flash, which wastes too much RAM.
// Macro to build a standard lambda function that includes the necessary type conversions
#define OBJECT_MODEL_FUNC(...) OBJECT_MODEL_FUNC_BODY(LinearDeltaKinematics, __VA_ARGS__)
constexpr ObjectModelArrayDescriptor LinearDeltaKinematics::towersArrayDescriptor =
{
nullptr, // no lock needed
[] (const ObjectModel *self, const ObjectExplorationContext&) noexcept -> size_t { return ((const LinearDeltaKinematics*)self)->numTowers; },
[] (const ObjectModel *self, ObjectExplorationContext& context) noexcept -> ExpressionValue { return ExpressionValue(self, 1); }
};
constexpr ObjectModelTableEntry LinearDeltaKinematics::objectModelTable[] =
{
// Within each group, these entries must be in alphabetical order
// 0. kinematics members
{ "deltaRadius", OBJECT_MODEL_FUNC(self->radius, 3), ObjectModelEntryFlags::none },
{ "homedHeight", OBJECT_MODEL_FUNC(self->homedHeight, 3), ObjectModelEntryFlags::none },
{ "name", OBJECT_MODEL_FUNC(self->GetName(true)), ObjectModelEntryFlags::none },
{ "printRadius", OBJECT_MODEL_FUNC(self->printRadius, 1), ObjectModelEntryFlags::none },
{ "towers", OBJECT_MODEL_FUNC_NOSELF(&towersArrayDescriptor), ObjectModelEntryFlags::none },
{ "xTilt", OBJECT_MODEL_FUNC(self->xTilt, 3), ObjectModelEntryFlags::none },
{ "yTilt", OBJECT_MODEL_FUNC(self->yTilt, 3), ObjectModelEntryFlags::none },
// 1. tower members
{ "angleCorrection", OBJECT_MODEL_FUNC(self->angleCorrections[context.GetLastIndex()], 3), ObjectModelEntryFlags::none },
{ "diagonal", OBJECT_MODEL_FUNC(self->diagonals[context.GetLastIndex()], 3), ObjectModelEntryFlags::none },
{ "endstopAdjustment", OBJECT_MODEL_FUNC(self->endstopAdjustments[context.GetLastIndex()], 3), ObjectModelEntryFlags::none },
{ "xPos", OBJECT_MODEL_FUNC(self->towerX[context.GetLastIndex()], 3), ObjectModelEntryFlags::none },
{ "yPos", OBJECT_MODEL_FUNC(self->towerY[context.GetLastIndex()], 3), ObjectModelEntryFlags::none },
};
constexpr uint8_t LinearDeltaKinematics::objectModelTableDescriptor[] = { 2, 7, 5 };
DEFINE_GET_OBJECT_MODEL_TABLE(LinearDeltaKinematics)
#endif
LinearDeltaKinematics::LinearDeltaKinematics() noexcept : RoundBedKinematics(KinematicsType::linearDelta, SegmentationType(false, false, false)), numTowers(UsualNumTowers)
{
Init();
}
// Return the name of the current kinematics
const char *LinearDeltaKinematics::GetName(bool forStatusReport) const noexcept
{
return (forStatusReport) ? "delta" : "Linear delta";
}
void LinearDeltaKinematics::Init() noexcept
{
radius = DefaultDeltaRadius;
xTilt = yTilt = 0.0;
printRadius = DefaultPrintRadius;
homedHeight = DefaultDeltaHomedHeight;
doneAutoCalibration = false;
for (size_t axis = 0; axis < UsualNumTowers; ++axis)
{
angleCorrections[axis] = 0.0;
}
for (size_t axis = 0; axis < MaxTowers; ++axis)
{
diagonals[axis] = DefaultDiagonal;
towerX[axis] = towerY[axis] = 0.0;
endstopAdjustments[axis] = 0.0;
}
Recalc();
}
void LinearDeltaKinematics::Recalc() noexcept
{
towerX[DELTA_A_AXIS] = -(radius * cosf((30 + angleCorrections[DELTA_A_AXIS]) * DegreesToRadians));
towerY[DELTA_A_AXIS] = -(radius * sinf((30 + angleCorrections[DELTA_A_AXIS]) * DegreesToRadians));
towerX[DELTA_B_AXIS] = +(radius * cosf((30 - angleCorrections[DELTA_B_AXIS]) * DegreesToRadians));
towerY[DELTA_B_AXIS] = -(radius * sinf((30 - angleCorrections[DELTA_B_AXIS]) * DegreesToRadians));
towerX[DELTA_C_AXIS] = -(radius * sinf(angleCorrections[DELTA_C_AXIS] * DegreesToRadians));
towerY[DELTA_C_AXIS] = +(radius * cosf(angleCorrections[DELTA_C_AXIS] * DegreesToRadians));
Xbc = towerX[DELTA_C_AXIS] - towerX[DELTA_B_AXIS];
Xca = towerX[DELTA_A_AXIS] - towerX[DELTA_C_AXIS];
Xab = towerX[DELTA_B_AXIS] - towerX[DELTA_A_AXIS];
Ybc = towerY[DELTA_C_AXIS] - towerY[DELTA_B_AXIS];
Yca = towerY[DELTA_A_AXIS] - towerY[DELTA_C_AXIS];
Yab = towerY[DELTA_B_AXIS] - towerY[DELTA_A_AXIS];
Q = (Xab * towerY[DELTA_C_AXIS] + Xca * towerY[DELTA_B_AXIS] + Xbc * towerY[DELTA_A_AXIS]) * 2;
Q2 = fsquare(Q);
// Calculate the squares of the diagonals and the base carriage heights when the printer is homed, i.e. the carriages are at the endstops
// Also calculate the always-reachable height
alwaysReachableHeight = homedHeight;
for (size_t axis = 0; axis < numTowers; ++axis)
{
D2[axis] = fsquare(diagonals[axis]);
homedCarriageHeights[axis] = homedHeight
+ fastSqrtf(D2[axis] - ((axis < UsualNumTowers) ? fsquare(radius) : fsquare(towerX[axis]) + fsquare(towerY[axis])))
+ endstopAdjustments[axis];
const float heightLimit = homedCarriageHeights[axis] - diagonals[axis];
if (heightLimit < alwaysReachableHeight)
{
alwaysReachableHeight = heightLimit;
}
}
// Calculate coreKa, corrKb and coreKc which are used by the forward transform
const float coreFa = fsquare(towerX[DELTA_A_AXIS]) + fsquare(towerY[DELTA_A_AXIS]);
const float coreFb = fsquare(towerX[DELTA_B_AXIS]) + fsquare(towerY[DELTA_B_AXIS]);
const float coreFc = fsquare(towerX[DELTA_C_AXIS]) + fsquare(towerY[DELTA_C_AXIS]);
coreKa = (D2[DELTA_B_AXIS] - D2[DELTA_C_AXIS]) + (coreFc - coreFb);
coreKb = (D2[DELTA_C_AXIS] - D2[DELTA_A_AXIS]) + (coreFa - coreFc);
coreKc = (D2[DELTA_A_AXIS] - D2[DELTA_B_AXIS]) + (coreFb - coreFa);
printRadiusSquared = fsquare(printRadius);
if (reprap.Debug(moduleMove))
{
debugPrintf("HCH:");
for (size_t i = 0; i < numTowers; ++i)
{
debugPrintf(" %.2f", (double)homedCarriageHeights[i]);
}
debugPrintf("\n");
}
}
// Make the average of the endstop adjustments zero, without changing the individual homed carriage heights
void LinearDeltaKinematics::NormaliseEndstopAdjustments() noexcept
{
const float eav = (endstopAdjustments[DELTA_A_AXIS] + endstopAdjustments[DELTA_B_AXIS] + endstopAdjustments[DELTA_C_AXIS])/3.0;
for (size_t i = 0; i < numTowers; ++i)
{
endstopAdjustments[i] -= eav;
}
homedHeight += eav;
}
// Calculate the motor position for a single tower from a Cartesian coordinate.
float LinearDeltaKinematics::Transform(const float machinePos[], size_t axis) const noexcept
{
if (axis < numTowers)
{
return fastSqrtf(D2[axis] - fsquare(machinePos[X_AXIS] - towerX[axis]) - fsquare(machinePos[Y_AXIS] - towerY[axis]))
+ machinePos[Z_AXIS]
+ (machinePos[X_AXIS] * xTilt)
+ (machinePos[Y_AXIS] * yTilt);
}
else
{
return machinePos[axis];
}
}
// Calculate the Cartesian coordinates from the motor coordinates
void LinearDeltaKinematics::ForwardTransform(float Ha, float Hb, float Hc, float machinePos[XYZ_AXES]) const noexcept
{
// Calculate RSUT such that x = (Uz + S)/Q, y = -(Rz + T)/Q
const float R = ((Xbc * Ha) + (Xca * Hb) + (Xab * Hc)) * 2;
const float U = ((Ybc * Ha) + (Yca * Hb) + (Yab * Hc)) * 2;
// Note, Ka + Kb + Kc = 0 so we could calculate just two of them
const float Ka = coreKa + (fsquare(Hc) - fsquare(Hb)),
Kb = coreKb + (fsquare(Ha) - fsquare(Hc)),
Kc = coreKc + (fsquare(Hb) - fsquare(Ha));
const float S = Ka * towerY[DELTA_A_AXIS] + Kb * towerY[DELTA_B_AXIS] + Kc * towerY[DELTA_C_AXIS];
const float T = Ka * towerX[DELTA_A_AXIS] + Kb * towerX[DELTA_B_AXIS] + Kc * towerX[DELTA_C_AXIS];
const float A = fsquare(U) + fsquare(R) + Q2;
const float minusHalfB = Q2 * Ha
+ Q * (U * towerX[DELTA_A_AXIS] - R * towerY[DELTA_A_AXIS])
- (R * T + U * S);
const float C = fsquare(towerX[DELTA_A_AXIS] * Q - S) + fsquare(towerY[DELTA_A_AXIS] * Q + T) + (fsquare(Ha) - D2[DELTA_A_AXIS]) * Q2;
const float z = (minusHalfB - fastSqrtf(fsquare(minusHalfB) - A * C)) / A;
machinePos[X_AXIS] = (U * z + S) / Q;
machinePos[Y_AXIS] = -(R * z + T) / Q;
machinePos[Z_AXIS] = z - ((machinePos[X_AXIS] * xTilt) + (machinePos[Y_AXIS] * yTilt));
// debugPrintf("Ha=%f Hb=%f Hc=%f Ka=%f Kb=%f Kc=%f\n", (double)Ha, (double)Hb, (double)Hc, (double)Ka, (double)Kb, (double)Kc);
// debugPrintf("Q=%f R=%f U=%f S=%f T=%f A=%f B=%f C=%f\n", (double)Q, (double)R, (double)U, (double)S, (double)T, (double)A, (double)minusHalfB, (double)C);
}
// Convert Cartesian coordinates to motor steps
bool LinearDeltaKinematics::CartesianToMotorSteps(const float machinePos[], const float stepsPerMm[],
size_t numVisibleAxes, size_t numTotalAxes, int32_t motorPos[], bool isCoordinated) const noexcept
{
bool ok = true;
for (size_t axis = 0; axis < numTowers; ++axis)
{
const float pos = Transform(machinePos, axis);
if (std::isnan(pos) || std::isinf(pos))
{
ok = false;
}
else
{
motorPos[axis] = lrintf(pos * stepsPerMm[axis]);
}
}
// Transform any additional axes linearly
for (size_t axis = numTowers; axis < numVisibleAxes; ++axis)
{
motorPos[axis] = lrintf(machinePos[axis] * stepsPerMm[axis]);
}
return ok;
}
// Convert motor coordinates to machine coordinates. Used after homing and after individual motor moves.
void LinearDeltaKinematics::MotorStepsToCartesian(const int32_t motorPos[], const float stepsPerMm[], size_t numVisibleAxes, size_t numTotalAxes, float machinePos[]) const noexcept
{
ForwardTransform(motorPos[DELTA_A_AXIS]/stepsPerMm[DELTA_A_AXIS], motorPos[DELTA_B_AXIS]/stepsPerMm[DELTA_B_AXIS], motorPos[DELTA_C_AXIS]/stepsPerMm[DELTA_C_AXIS], machinePos);
// Convert any additional axes linearly
for (size_t drive = numTowers; drive < numVisibleAxes; ++drive)
{
machinePos[drive] = motorPos[drive]/stepsPerMm[drive];
}
}
// Limit the Cartesian position that the user wants to move to returning true if we adjusted the position
LimitPositionResult LinearDeltaKinematics::LimitPosition(float finalCoords[], const float * null initialCoords,
size_t numVisibleAxes, AxesBitmap axesToLimit, bool isCoordinated, bool applyM208Limits) const noexcept
{
bool limited = false;
// If axes have been homed on a delta printer and this isn't a homing move, check for movements outside limits.
// Skip this check if axes have not been homed, so that extruder-only moves are allowed before homing
if ((axesToLimit & XyzAxes) == XyzAxes)
{
// Constrain the move to be within the build radius
const float diagonalSquared = fsquare(finalCoords[X_AXIS]) + fsquare(finalCoords[Y_AXIS]);
if (applyM208Limits && diagonalSquared > printRadiusSquared)
{
const float factor = fastSqrtf(printRadiusSquared / diagonalSquared);
finalCoords[X_AXIS] *= factor;
finalCoords[Y_AXIS] *= factor;
limited = true;
}
// Constrain the position to be within the reachable height
if (initialCoords == nullptr)
{
// Asking to limit a single position
if (finalCoords[Z_AXIS] > alwaysReachableHeight)
{
for (size_t tower = 0; tower < UsualNumTowers; ++tower)
{
const float carriageHeight = Transform(finalCoords, tower);
if (carriageHeight > homedCarriageHeights[tower])
{
finalCoords[Z_AXIS] -= (carriageHeight - homedCarriageHeights[tower]);
limited = true;
}
}
}
}
else if (finalCoords[Z_AXIS] > alwaysReachableHeight || initialCoords[Z_AXIS] > alwaysReachableHeight)
{
// Asking to limit all positions along a straight line
// Determine the maximum reachable height at the final position and all intermediate positions
const float dx = finalCoords[X_AXIS] - initialCoords[X_AXIS],
dy = finalCoords[Y_AXIS] - initialCoords[Y_AXIS];
const float P2 = fsquare(dx) + fsquare(dy); // square of the distance moved in the XY plane
float dz = finalCoords[Z_AXIS] - initialCoords[Z_AXIS];
float Q2 = P2 + fsquare(dz); // square of the total distance moved
if (Q2 != 0.0) // if there is any XYZ movement
{
// If t is the proportion of movement completed from initial to final coordinates, the t-value corresponding to the maximum tower height is:
// t = (+/- dz*sqrt(d^2*P2 - (dx*(y0-yt)-dy*(x0-xt))^2)*Q
// -(x0-xt)*dx*Q2
// -(y0-yt)*dy*Q2
// )
// /(P2*Q2)
// We want the root that increases with increasing dz, i.e. positive Z movement delays the maximum
for (size_t tower = 0; tower < numTowers; ++tower)
{
const float tx = initialCoords[X_AXIS] - towerX[tower],
ty = initialCoords[Y_AXIS] - towerY[tower];
const float discriminant = (D2[tower] * P2) - fsquare((dx * ty) - (dy * tx));
bool limitFinalHeight;
bool again; // we may need to iterate
do
{
again = false;
if (discriminant < 0.0)
{
// There is no maximum carriage height on this tower, so the maximum must occur at the initial or final point.
// We assume that the initial point is within range, so check the final point.
limitFinalHeight = true;
}
else
{
const float tP2Q2 = dz * fastSqrtf(discriminant * Q2) - ((tx * dx) + (ty * dy)) * Q2;
const float P2Q2 = P2 * Q2;
if (tP2Q2 >= P2Q2)
{
limitFinalHeight = true; // the maximum is beyond the final position
}
else
{
limitFinalHeight = false;
if (tP2Q2 > 0.0)
{
const float t = tP2Q2/P2Q2;
float tempCoords[XYZ_AXES];
tempCoords[X_AXIS] = initialCoords[X_AXIS] + t * dx;
tempCoords[Y_AXIS] = initialCoords[Y_AXIS] + t * dy;
tempCoords[Z_AXIS] = initialCoords[Z_AXIS] + t * dz;
const float carriageHeight = Transform(tempCoords, tower);
if (carriageHeight > homedCarriageHeights[tower])
{
// We can't do this move as requested
const float proposedAdjustment = carriageHeight - homedCarriageHeights[tower] + 0.5;
if (dz >= proposedAdjustment)
{
// There is some chance that if we reduce the requested final Z coordinate, we can do the move
finalCoords[Z_AXIS] -= proposedAdjustment;
dz -= proposedAdjustment;;
limited = true;
// Update the intermediate variables that have changed
again = true;
Q2 = P2 + fsquare(dz);
if (reprap.Debug(moduleMove))
{
debugPrintf("Limit tower %u, t=%.2f\n", tower, (double)t);
}
}
else
{
return (limited) ? LimitPositionResult::adjustedAndIntermediateUnreachable : LimitPositionResult::intermediateUnreachable;
}
}
}
}
}
} while (again);
if (limitFinalHeight)
{
const float carriageHeight = Transform(finalCoords, tower);
if (carriageHeight > homedCarriageHeights[tower])
{
const float proposedAdjustment = carriageHeight - homedCarriageHeights[tower];
if (dz >= proposedAdjustment)
{
finalCoords[Z_AXIS] -= proposedAdjustment;
limited = true;
if (reprap.Debug(moduleMove))
{
debugPrintf("Limit tower %u\n", tower);
}
if (tower + 1 < numTowers)
{
dz -= proposedAdjustment;
Q2 = P2 + fsquare(dz);
}
}
else
{
return (limited) ? LimitPositionResult::adjustedAndIntermediateUnreachable : LimitPositionResult::intermediateUnreachable;
}
}
}
}
}
}
if (applyM208Limits && finalCoords[Z_AXIS] < reprap.GetPlatform().AxisMinimum(Z_AXIS))
{
finalCoords[Z_AXIS] = reprap.GetPlatform().AxisMinimum(Z_AXIS);
limited = true;
}
}
// Limit any additional axes according to the M208 limits
if (applyM208Limits && LimitPositionFromAxis(finalCoords, numTowers, numVisibleAxes, axesToLimit))
{
limited = true;
}
return (limited) ? LimitPositionResult::adjusted : LimitPositionResult::ok;
}
// Return the initial Cartesian coordinates we assume after switching to this kinematics
void LinearDeltaKinematics::GetAssumedInitialPosition(size_t numAxes, float positions[]) const noexcept
{
for (size_t i = 0; i < numAxes; ++i)
{
positions[i] = 0.0;
}
positions[Z_AXIS] = homedHeight;
}
// Auto calibrate from a set of probe points returning true if it failed
bool LinearDeltaKinematics::DoAutoCalibration(size_t numFactors, const RandomProbePointSet& probePoints, const StringRef& reply) noexcept
{
constexpr size_t NumDeltaFactors = 9; // maximum number of delta machine factors we can adjust
if (numFactors < 3 || numFactors > NumDeltaFactors || numFactors == 5)
{
reply.printf("Delta calibration with %d factors requested but only 3, 4, 6, 7, 8 and 9 supported", numFactors);
return true;
}
if (reprap.Debug(moduleMove))
{
String<StringLength256> scratchString;
PrintParameters(scratchString.GetRef());
debugPrintf("%s\n", scratchString.c_str());
}
// Transform the probing points to motor endpoints and store them in a matrix, so that we can do multiple iterations using the same data
FixedMatrix<floatc_t, MaxCalibrationPoints, UsualNumTowers> probeMotorPositions;
floatc_t corrections[MaxCalibrationPoints];
Deviation initialDeviation;
const size_t numPoints = probePoints.NumberOfProbePoints();
{
floatc_t initialSum = 0.0, initialSumOfSquares = 0.0;
for (size_t i = 0; i < numPoints; ++i)
{
corrections[i] = 0.0;
float machinePos[XYZ_AXES];
const floatc_t zp = reprap.GetMove().GetProbeCoordinates(i, machinePos[X_AXIS], machinePos[Y_AXIS], probePoints.PointWasCorrected(i));
machinePos[Z_AXIS] = 0.0;
probeMotorPositions(i, DELTA_A_AXIS) = Transform(machinePos, DELTA_A_AXIS);
probeMotorPositions(i, DELTA_B_AXIS) = Transform(machinePos, DELTA_B_AXIS);
probeMotorPositions(i, DELTA_C_AXIS) = Transform(machinePos, DELTA_C_AXIS);
initialSum += zp;
initialSumOfSquares += fcsquare(zp);
}
initialDeviation.Set(initialSumOfSquares, initialSum, numPoints);
}
// Do 1 or more Newton-Raphson iterations
Deviation finalDeviation;
unsigned int iteration = 0;
for (;;)
{
// Build a Nx9 matrix of derivatives with respect to xa, xb, yc, za, zb, zc, diagonal.
FixedMatrix<floatc_t, MaxCalibrationPoints, NumDeltaFactors> derivativeMatrix;
for (size_t i = 0; i < numPoints; ++i)
{
for (size_t j = 0; j < numFactors; ++j)
{
const size_t adjustedJ = (numFactors == 8 && j >= 6) ? j + 1 : j; // skip diagonal rod length if doing 8-factor calibration
const floatc_t d =
ComputeDerivative(adjustedJ, probeMotorPositions(i, DELTA_A_AXIS), probeMotorPositions(i, DELTA_B_AXIS), probeMotorPositions(i, DELTA_C_AXIS));
if (std::isnan(d)) // a couple of users have reported getting Nans in the derivative, probably due to points being unreachable
{
reply.printf("Auto calibration failed because probe point P%u was unreachable using the current delta parameters. Try a smaller probing radius.", i);
return true;
}
derivativeMatrix(i, j) = d;
}
}
if (reprap.Debug(moduleMove))
{
PrintMatrix("Derivative matrix", derivativeMatrix, numPoints, numFactors);
}
// Now build the normal equations for least squares fitting
FixedMatrix<floatc_t, NumDeltaFactors, NumDeltaFactors + 1> normalMatrix;
for (size_t i = 0; i < numFactors; ++i)
{
for (size_t j = 0; j < numFactors; ++j)
{
floatc_t temp = derivativeMatrix(0, i) * derivativeMatrix(0, j);
for (size_t k = 1; k < numPoints; ++k)
{
temp += derivativeMatrix(k, i) * derivativeMatrix(k, j);
}
normalMatrix(i, j) = temp;
}
floatc_t temp = derivativeMatrix(0, i) * -((floatc_t)probePoints.GetZHeight(0) + corrections[0]);
for (size_t k = 1; k < numPoints; ++k)
{
temp += derivativeMatrix(k, i) * -((floatc_t)probePoints.GetZHeight(k) + corrections[k]);
}
normalMatrix(i, numFactors) = temp;
}
if (reprap.Debug(moduleMove))
{
PrintMatrix("Normal matrix", normalMatrix, numFactors, numFactors + 1);
}
if (!normalMatrix.GaussJordan(numFactors, numFactors + 1))
{
reply.copy("Unable to calculate calibration parameters. Please choose different probe points.");
return true;
}
floatc_t solution[NumDeltaFactors];
for (size_t i = 0; i < numFactors; ++i)
{
solution[i] = normalMatrix(i, numFactors);
}
if (reprap.Debug(moduleMove))
{
PrintMatrix("Solved matrix", normalMatrix, numFactors, numFactors + 1);
PrintVector("Solution", solution, numFactors);
// Calculate and display the residuals
// Save a little stack by not allocating a residuals vector, because stack for it doesn't only get reserved when debug is enabled.
debugPrintf("Residuals:");
for (size_t i = 0; i < numPoints; ++i)
{
floatc_t residual = probePoints.GetZHeight(i);
for (size_t j = 0; j < numFactors; ++j)
{
residual += solution[j] * derivativeMatrix(i, j);
}
debugPrintf(" %7.4f", (double)residual);
}
debugPrintf("\n");
}
{
// Save the old homed carriage heights before we change the endstop corrections
float heightAdjust[UsualNumTowers];
for (size_t drive = 0; drive < UsualNumTowers; ++drive)
{
heightAdjust[drive] = homedCarriageHeights[drive];
}
Adjust(numFactors, solution); // adjust the delta parameters
for (size_t drive = 0; drive < UsualNumTowers; ++drive)
{
heightAdjust[drive] = homedCarriageHeights[drive] - heightAdjust[drive];
}
// Adjust the motor endpoints to allow for the change to endstop adjustments
reprap.GetMove().AdjustMotorPositions(heightAdjust, UsualNumTowers);
}
// Calculate the expected probe heights using the new parameters
{
floatc_t expectedResiduals[MaxCalibrationPoints];
floatc_t finalSum = 0.0, finalSumOfSquares = 0.0;
for (size_t i = 0; i < numPoints; ++i)
{
for (size_t axis = 0; axis < UsualNumTowers; ++axis)
{
probeMotorPositions(i, axis) += solution[axis];
}
float newPosition[XYZ_AXES];
ForwardTransform(probeMotorPositions(i, DELTA_A_AXIS), probeMotorPositions(i, DELTA_B_AXIS), probeMotorPositions(i, DELTA_C_AXIS), newPosition);
corrections[i] = newPosition[Z_AXIS];
expectedResiduals[i] = probePoints.GetZHeight(i) + newPosition[Z_AXIS];
finalSum += expectedResiduals[i];
finalSumOfSquares += fcsquare(expectedResiduals[i]);
}
finalDeviation.Set(finalSumOfSquares, finalSum, numPoints);
if (reprap.Debug(moduleMove))
{
PrintVector("Expected probe error", expectedResiduals, numPoints);
}
}
// Decide whether to do another iteration. Two is slightly better than one, but three doesn't improve things.
// Alternatively, we could stop when the expected RMS error is only slightly worse than the RMS of the residuals.
++iteration;
if (iteration == 2)
{
break;
}
}
// Print out the calculation time
//debugPrintf("Time taken %dms\n", (reprap.GetPlatform()->GetInterruptClocks() - startTime) * 1000 / DDA::stepClockRate);
if (reprap.Debug(moduleMove))
{
String<StringLength256> scratchString;
PrintParameters(scratchString.GetRef());
debugPrintf("%s\n", scratchString.c_str());
}
reprap.GetMove().SetInitialCalibrationDeviation(initialDeviation);
reprap.GetMove().SetLatestCalibrationDeviation(finalDeviation, numFactors);
reply.printf("Calibrated %d factors using %d points, (mean, deviation) before (%.3f, %.3f) after (%.3f, %.3f)",
numFactors, numPoints,
(double)initialDeviation.GetMean(), (double)initialDeviation.GetDeviationFromMean(),
(double)finalDeviation.GetMean(), (double)finalDeviation.GetDeviationFromMean());
// We don't want to call MessageF(LogMessage, "%s\n", reply.c_str()) here because that will allocate a buffer within MessageF, which adds to our stack usage.
// Better to allocate the buffer here so that it uses the same stack space as the arrays that we have finished with
{
String<StringLength256> scratchString;
scratchString.printf("%s\n", reply.c_str());
reprap.GetPlatform().Message(LogWarn, scratchString.c_str());
}
doneAutoCalibration = true;
return false;
}
// Return the type of motion computation needed by an axis
MotionType LinearDeltaKinematics::GetMotionType(size_t axis) const noexcept
{
return (axis < numTowers) ? MotionType::segmentFreeDelta : MotionType::linear;
}
// 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 LinearDeltaKinematics::ComputeDerivative(unsigned int deriv, float ha, float hb, float hc) const noexcept
{
const float perturb = 0.2; // perturbation amount in mm or degrees
LinearDeltaKinematics 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.angleCorrections[DELTA_A_AXIS] += perturb;
loParams.angleCorrections[DELTA_A_AXIS] -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 5:
hiParams.angleCorrections[DELTA_B_AXIS] += perturb;
loParams.angleCorrections[DELTA_B_AXIS] -= perturb;
hiParams.Recalc();
loParams.Recalc();
break;
case 6:
for (size_t tower = 0; tower < UsualNumTowers; ++tower)
{
hiParams.diagonals[tower] += perturb;
loParams.diagonals[tower] -= perturb;
}
hiParams.Recalc();
loParams.Recalc();
break;
case 7:
case 8:
// X and Y tilt
break;
}
float newPos[XYZ_AXES];
hiParams.ForwardTransform((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.ForwardTransform((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)/(floatc_t)(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 LinearDeltaKinematics::Adjust(size_t numFactors, const floatc_t v[]) noexcept
{
// Update the delta radius
const float oldRadius = radius; // we will need this to correct the endstop adjustments
if (numFactors >= 4)
{
radius += (float)v[3];
}
// Update endstop adjustments and rod lengths. If we changed the delta radius or the rod lengths then the endstop adjustments need to take account of that too.
for (size_t tower = 0; tower < UsualNumTowers; ++tower)
{
if (numFactors >= 4)
{
const float oldCarriageHeight = fastSqrtf(fsquare(diagonals[tower]) - fsquare(oldRadius));
if (numFactors == 7 || numFactors == 9)
{
diagonals[tower] += (float)v[6];
}
const float newCarriageHeight = fastSqrtf(fsquare(diagonals[tower]) - fsquare(radius));
endstopAdjustments[tower] += oldCarriageHeight - newCarriageHeight;
}
endstopAdjustments[tower] += (float)v[tower];
}
NormaliseEndstopAdjustments();
if (numFactors >= 6)
{
angleCorrections[DELTA_A_AXIS] += (float)v[4];
angleCorrections[DELTA_B_AXIS] += (float)v[5];
if (numFactors == 8)
{
xTilt += (float)v[6]/printRadius;
yTilt += (float)v[7]/printRadius;
}
else if (numFactors == 9)
{
xTilt += (float)v[7]/printRadius;
yTilt += (float)v[8]/printRadius;
}
}
Recalc();
// 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 autocalibration
// run will correct it.
}
// Print all the parameters for debugging
void LinearDeltaKinematics::PrintParameters(const StringRef& reply) const noexcept
{
reply.printf("Stops X%.3f Y%.3f Z%.3f height %.3f diagonals",
(double)endstopAdjustments[DELTA_A_AXIS], (double)endstopAdjustments[DELTA_B_AXIS], (double)endstopAdjustments[DELTA_C_AXIS], (double)homedHeight);
for (size_t tower = 0; tower < numTowers; ++tower)
{
reply.catf("%c%.3f", (tower == 0) ? ' ' : ':', (double)diagonals[tower]);
}
reply.catf(" radius %.3f xcorr %.2f ycorr %.2f zcorr %.2f xtilt %.3f%% ytilt %.3f%%\n",
(double)radius,
(double)angleCorrections[DELTA_A_AXIS], (double)angleCorrections[DELTA_B_AXIS], (double)angleCorrections[DELTA_C_AXIS],
(double)(xTilt * 100.0), (double)(yTilt * 100.0));
}
#if HAS_MASS_STORAGE || HAS_SBC_INTERFACE
// Write the parameters that are set by auto calibration to a file, returning true if success
bool LinearDeltaKinematics::WriteCalibrationParameters(FileStore *f) const noexcept
{
bool ok = f->Write("; Delta parameters\n");
if (ok)
{
String<StringLength256> scratchString;
scratchString.copy("M665 ");
for (size_t tower = 0; tower < numTowers; ++tower)
{
scratchString.catf("%c%.3f", (tower == 0) ? 'L' : ':', (double)diagonals[tower]);
}
scratchString.catf(" R%.3f H%.3f B%.1f X%.3f Y%.3f Z%.3f\n",
(double)radius, (double)homedHeight, (double)printRadius,
(double)angleCorrections[DELTA_A_AXIS], (double)angleCorrections[DELTA_B_AXIS], (double)angleCorrections[DELTA_C_AXIS]);
ok = f->Write(scratchString.c_str());
if (ok)
{
scratchString.printf("M666 X%.3f Y%.3f Z%.3f A%.2f B%.2f\n",
(double)endstopAdjustments[X_AXIS], (double)endstopAdjustments[Y_AXIS], (double)endstopAdjustments[Z_AXIS], (double)(xTilt * 100.0), (double)(yTilt * 100.0));
ok = f->Write(scratchString.c_str());
}
}
return ok;
}
// Write any calibration data that we need to resume a print after power fail, returning true if successful
bool LinearDeltaKinematics::WriteResumeSettings(FileStore *f) const noexcept
{
return !doneAutoCalibration || WriteCalibrationParameters(f);
}
#endif
// Get the bed tilt fraction for the specified axis
float LinearDeltaKinematics::GetTiltCorrection(size_t axis) const noexcept
{
return (axis == X_AXIS) ? xTilt : (axis == Y_AXIS) ? yTilt : 0.0;
}
// Set the parameters from a M665, M666 or M669 command
// Return true if we changed any parameters. Set 'error' true if there was an error, otherwise leave it alone.
bool LinearDeltaKinematics::Configure(unsigned int mCode, GCodeBuffer& gb, const StringRef& reply, bool& error) THROWS(GCodeException) /*override*/
{
switch(mCode)
{
case 665:
{
bool seen = false;
if (gb.Seen('L'))
{
seen = true;
size_t numValues = min<size_t>(reprap.GetGCodes().GetTotalAxes(), MaxTowers);
gb.GetFloatArray(diagonals, numValues, false);
while (numValues < 3)
{
diagonals[numValues++] = diagonals[0];
}
numTowers = numValues;
}
gb.TryGetFValue('R', radius, seen);
if (gb.Seen('B'))
{
printRadius = gb.GetFValue();
// Set the axis limits so that DWC reports them correctly (they are not otherwise used for deltas, except Z min)
Platform& p = reprap.GetPlatform();
p.SetAxisMinimum(X_AXIS, -printRadius, false);
p.SetAxisMinimum(Y_AXIS, -printRadius, false);
p.SetAxisMaximum(X_AXIS, printRadius, false);
p.SetAxisMaximum(Y_AXIS, printRadius, false);
seen = true;
}
gb.TryGetFValue('X', angleCorrections[DELTA_A_AXIS], seen);
gb.TryGetFValue('Y', angleCorrections[DELTA_B_AXIS], seen);
gb.TryGetFValue('Z', angleCorrections[DELTA_C_AXIS], seen);
if (gb.Seen('H'))
{
homedHeight = gb.GetFValue();
// Set the Z axis maximum so that DWC reports it correctly (it is not otherwise used for deltas)
reprap.GetPlatform().SetAxisMaximum(Z_AXIS, homedHeight, false);
seen = true;
}
if (seen)
{
Recalc();
}
else
{
reply.copy("Diagonals");
for (size_t tower = 0; tower < numTowers; ++tower)
{
reply.catf("%c%.3f", (tower == 0) ? ' ' : ':', (double)diagonals[tower]);
}
reply.catf(", delta radius %.3f, homed height %.3f, bed radius %.1f"
", X %.3f" DEGREE_SYMBOL ", Y %.3f" DEGREE_SYMBOL ", Z %.3f" DEGREE_SYMBOL,
(double)radius,
(double)homedHeight, (double)printRadius,
(double)angleCorrections[DELTA_A_AXIS], (double)angleCorrections[DELTA_B_AXIS], (double)angleCorrections[DELTA_C_AXIS]);
}
return seen;
}
case 666:
{
bool seen = false;
for (size_t tower = 0; tower < numTowers; ++tower)
{
gb.TryGetFValue("XYZUVW"[tower], endstopAdjustments[tower], seen);
}
if (gb.Seen('A'))
{
xTilt = gb.GetFValue() * 0.01;
seen = true;
}
if (gb.Seen('B'))
{
yTilt = gb.GetFValue() * 0.01;
seen = true;
}
if (seen)
{
Recalc();
}
else
{
reply.printf("Endstop adjustments X%.2f Y%.2f Z%.2f, tilt X%.2f%% Y%.2f%%",
(double)endstopAdjustments[X_AXIS], (double)endstopAdjustments[Y_AXIS], (double)endstopAdjustments[Z_AXIS],
(double)(xTilt * 100.0), (double)(yTilt * 100.0));
}
return seen;
}
case 669:
{
const bool seenSeg = TryConfigureSegmentation(gb); // configure optional segmentation
// X and Y give the X and Y coordinates of the additional towers beyond the first three
// The correct number of L parameters must have been given in the M665 command first
size_t numX = 0, numY = 0;
if (gb.Seen('X'))
{
numX = MaxTowers - UsualNumTowers;
gb.GetFloatArray(towerX + UsualNumTowers, numX, false);
if (numX != numTowers - UsualNumTowers)
{
reply.copy("Wrong number of X values");
error = true;
return true;
}
}
if (gb.Seen('Y'))
{
numY = MaxTowers - UsualNumTowers;
gb.GetFloatArray(towerY + UsualNumTowers, numY, false);
if (numY != numTowers - UsualNumTowers)
{
reply.copy("Wrong number of Y values");
error = true;
return true;
}
}
if (numX != 0 || numY != 0)
{
Recalc(); // recalculate the homed carriage heights
return true;
}
if (seenSeg)
{
return false;
}
return Kinematics::Configure(mCode, gb, reply, error);
}
default:
return Kinematics::Configure(mCode, gb, reply, error);
}
}
// Return the axes that we can assume are homed after executing a G92 command to set the specified axis coordinates
AxesBitmap LinearDeltaKinematics::AxesAssumedHomed(AxesBitmap g92Axes) const noexcept
{
// If all of X, Y and Z have been specified then we know the positions of all 3 tower motors, otherwise we don't
if ((g92Axes & XyzAxes) != XyzAxes)
{
g92Axes &= ~XyzAxes;
}
return g92Axes;
}
// Return the set of axes that must be homed prior to regular movement of the specified axes
AxesBitmap LinearDeltaKinematics::MustBeHomedAxes(AxesBitmap axesMoving, bool disallowMovesBeforeHoming) const noexcept
{
if (axesMoving.Intersects(XyzAxes))
{
axesMoving |= XyzAxes;
}
return axesMoving;
}
// This function is called when a request is made to home the axes in 'toBeHomed' and the axes in 'alreadyHomed' have already been homed.
// If we can proceed with homing some axes, return the name of the homing file to be called.
// If we can't proceed because other axes need to be homed first, return nullptr and pass those axes back in 'mustBeHomedFirst'.
AxesBitmap LinearDeltaKinematics::GetHomingFileName(AxesBitmap toBeHomed, AxesBitmap alreadyHomed, size_t numVisibleAxes, const StringRef& filename) const noexcept
{
// If homing X, Y or Z we must home all the towers
if (toBeHomed.Intersects(XyzAxes))
{
filename.copy("homedelta.g");
return AxesBitmap();
}
return Kinematics::GetHomingFileName(toBeHomed, alreadyHomed, numVisibleAxes, filename);
}
// This function is called from the step ISR when an endstop switch is triggered during homing.
// Return true if the entire homing move should be terminated, false if only the motor associated with the endstop switch should be stopped.
bool LinearDeltaKinematics::QueryTerminateHomingMove(size_t axis) const noexcept
{
return false;
}
// This function is called from the step ISR when an endstop switch is triggered during homing after stopping just one motor or all motors.
// Take the action needed to define the current position, normally by calling dda.SetDriveCoordinate().
void LinearDeltaKinematics::OnHomingSwitchTriggered(size_t axis, bool highEnd, const float stepsPerMm[], DDA& dda) const noexcept
{
if (axis < numTowers)
{
if (highEnd)
{
dda.SetDriveCoordinate(lrintf(homedCarriageHeights[axis] * stepsPerMm[axis]), axis);
}
}
else
{
// Assume that any additional axes are linear
const float hitPoint = (highEnd) ? reprap.GetPlatform().AxisMaximum(axis) : reprap.GetPlatform().AxisMinimum(axis);
dda.SetDriveCoordinate(lrintf(hitPoint * stepsPerMm[axis]), axis);
}
}
// Return a bitmap of axes that move linearly in response to the correct combination of linear motor movements.
// This is called to determine whether we can babystep the specified axis independently of regular motion.
// The DDA class has special support for delta printers, so we can baystep the Z axis.
AxesBitmap LinearDeltaKinematics::GetLinearAxes() const noexcept
{
return AxesBitmap::MakeFromBits(Z_AXIS);
}
#endif // SUPPORT_LINEAR_DELTA
// End
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