Exemple #1
0
def InterpolateNDFixedDuration(x0Vect_, x1Vect_, v0Vect_, v1Vect_, duration,
                               xminVect_, xmaxVect_, vmVect_, amVect_):
    assert (duration > 0)

    ndof = len(x0Vect_)
    assert (ndof == len(x1Vect_))
    assert (ndof == len(v0Vect_))
    assert (ndof == len(v1Vect_))
    assert (ndof == len(xminVect_))
    assert (ndof == len(xmaxVect_))
    assert (ndof == len(vmVect_))
    assert (ndof == len(amVect_))

    # Convert all vector elements into mp.mpf (if necessary)
    x0Vect = ConvertFloatArrayToMPF(x0Vect_)
    x1Vect = ConvertFloatArrayToMPF(x1Vect_)
    v0Vect = ConvertFloatArrayToMPF(v0Vect_)
    v1Vect = ConvertFloatArrayToMPF(v1Vect_)
    xminVect = ConvertFloatArrayToMPF(xminVect_)
    xmaxVect = ConvertFloatArrayToMPF(xmaxVect_)
    vmVect = ConvertFloatArrayToMPF(vmVect_)
    amVect = ConvertFloatArrayToMPF(amVect_)

    dVect = x1Vect - x0Vect

    duration = ConvertFloatToMPF(duration)

    curves = []
    for idof in xrange(ndof):
        curve = Interpolate1DFixedDuration(x0Vect[idof], x1Vect[idof],
                                           v0Vect[idof], v1Vect[idof],
                                           duration, vmVect[idof],
                                           amVect[idof])
        if curve.isEmpty:
            return ParabolicCurvesND()

        newCurve = _ImposeJointLimitFixedDuration(curve, xminVect[idof],
                                                  xmaxVect[idof], vmVect[idof],
                                                  amVect[idof])
        if newCurve.isEmpty:
            return ParabolicCurvesND()

        curves.append(newCurve)
    return ParabolicCurvesND(curves)
Exemple #2
0
def Interpolate1DFixedDuration(x0, x1, v0, v1, newDuration, vm, am):
    x0 = ConvertFloatToMPF(x0)
    x1 = ConvertFloatToMPF(x1)
    v0 = ConvertFloatToMPF(v0)
    v1 = ConvertFloatToMPF(v1)
    vm = ConvertFloatToMPF(vm)
    am = ConvertFloatToMPF(am)
    newDuration = ConvertFloatToMPF(newDuration)
    log.debug("\nx0 = {0}; x1 = {1}; v0 = {2}; v1 = {3}; vm = {4}; am = {5}; newDuration = {6}".\
              format(mp.nstr(x0, n=_prec), mp.nstr(x1, n=_prec), mp.nstr(v0, n=_prec), mp.nstr(v1, n=_prec),
                     mp.nstr(vm, n=_prec), mp.nstr(am, n=_prec), mp.nstr(newDuration, n=_prec)))

    # Check inputs
    assert (vm > zero)
    assert (am > zero)

    if (newDuration < -epsilon):
        return ParabolicCurve()
    if (newDuration <= epsilon):
        # Check if this is a stationary trajectory
        if (FuzzyEquals(x0, x1, epsilon) and FuzzyEquals(v0, v1, epsilon)):
            ramp0 = Ramp(v0, 0, 0, x0)
            newCurve = ParabolicCurve(ramp0)
            return newCurve
        else:
            # newDuration is too short to any movement to be made
            return ParabolicCurve()

    d = Sub(x1, x0)

    # First assume no velocity bound -> re-interpolated trajectory will have only two ramps.
    # Solve for a0 and a1 (the acceleration of the first and the last ramps).
    #         a0 = A + B/t0
    #         a1 = A + B/(t - t0)
    # where t is the (new) total duration, t0 is the (new) duration of the first ramp, and
    #         A = (v1 - v0)/t
    #         B = (2d/t) - (v0 + v1).
    newDurInverse = mp.fdiv(one, newDuration)
    A = Mul(Sub(v1, v0), newDurInverse)
    B = Sub(Prod([mp.mpf('2'), d, newDurInverse]), Add(v0, v1))

    interval0 = iv.mpf([zero, newDuration])  # initial interval for t0

    # Now consider the interval(s) computed from a0's constraints
    sum1 = Neg(Add(am, A))
    sum2 = Sub(am, A)
    C = mp.fdiv(B, sum1)
    D = mp.fdiv(B, sum2)

    log.debug("\nA = {0}; \nB = {1}; \nC = {2}; \nD = {3}; \nsum1 = {4}; \nsum2 = {5};".\
              format(mp.nstr(A, n=_prec), mp.nstr(B, n=_prec), mp.nstr(C, n=_prec), mp.nstr(D, n=_prec),
                     mp.nstr(sum1, n=_prec), mp.nstr(sum2, n=_prec)))

    if (sum1 > zero):
        # This implied that the duration is too short
        log.debug("the given duration ({0}) is too short.".format(newDuration))
        return ParabolicCurve()
    if (sum2 < zero):
        # This implied that the duration is too short
        log.debug("the given duration ({0}) is too short.".format(newDuration))
        return ParabolicCurve()

    if IsEqual(sum1, zero):
        raise NotImplementedError  # not yet considered
    elif sum1 > epsilon:
        log.debug("sum1 > 0. This implies that newDuration is too short.")
        return ParabolicCurve()
    else:
        interval1 = iv.mpf([C, inf])

    if IsEqual(sum2, zero):
        raise NotImplementedError  # not yet considered
    elif sum2 > epsilon:
        interval2 = iv.mpf([D, inf])
    else:
        log.debug("sum2 < 0. This implies that newDuration is too short.")
        return ParabolicCurve()

    if Sub(interval2.a, interval1.b) > epsilon or Sub(interval1.a,
                                                      interval2.b) > epsilon:
        # interval1 and interval2 do not intersect each other
        return ParabolicCurve()
    # interval3 = interval1 \cap interval2 : valid interval for t0 computed from a0's constraints
    interval3 = iv.mpf(
        [max(interval1.a, interval2.a),
         min(interval1.b, interval2.b)])

    # Now consider the interval(s) computed from a1's constraints
    if IsEqual(sum1, zero):
        raise NotImplementedError  # not yet considered
    elif sum1 > epsilon:
        log.debug("sum1 > 0. This implies that newDuration is too short.")
        return ParabolicCurve()
    else:
        interval4 = iv.mpf([Neg(inf), Add(C, newDuration)])

    if IsEqual(sum2, zero):
        raise NotImplementedError  # not yet considered
    elif sum2 > epsilon:
        interval5 = iv.mpf([Neg(inf), Add(D, newDuration)])
    else:
        log.debug("sum2 < 0. This implies that newDuration is too short.")
        return ParabolicCurve()

    if Sub(interval5.a, interval4.b) > epsilon or Sub(interval4.a,
                                                      interval5.b) > epsilon:
        log.debug("interval4 and interval5 do not intersect each other")
        return ParabolicCurve()
    # interval6 = interval4 \cap interval5 : valid interval for t0 computed from a1's constraints
    interval6 = iv.mpf(
        [max(interval4.a, interval5.a),
         min(interval4.b, interval5.b)])

    # import IPython; IPython.embed()

    if Sub(interval3.a, interval6.b) > epsilon or Sub(interval6.a,
                                                      interval3.b) > epsilon:
        log.debug("interval3 and interval6 do not intersect each other")
        return ParabolicCurve()
    # interval7 = interval3 \cap interval6
    interval7 = iv.mpf(
        [max(interval3.a, interval6.a),
         min(interval3.b, interval6.b)])

    if Sub(interval0.a, interval7.b) > epsilon or Sub(interval7.a,
                                                      interval0.b) > epsilon:
        log.debug("interval0 and interval7 do not intersect each other")
        return ParabolicCurve()
    # interval8 = interval0 \cap interval7 : valid interval of t0 when considering all constraints (from a0 and a1)
    interval8 = iv.mpf(
        [max(interval0.a, interval7.a),
         min(interval0.b, interval7.b)])

    # import IPython; IPython.embed()

    # We choose the value t0 (the duration of the first ramp) by selecting the mid point of the
    # valid interval of t0.

    t0 = _SolveForT0(A, B, newDuration, interval8)
    if t0 is None:
        # The fancy procedure fails. Now consider no optimization whatsoever.
        # TODO: Figure out why solving fails.
        t0 = mp.convert(interval8.mid)  # select the midpoint
        # return ParabolicCurve()
    t1 = Sub(newDuration, t0)

    a0 = Add(A, Mul(mp.fdiv(one, t0), B))
    if (Abs(t1) < epsilon):
        a1 = zero
    else:
        a1 = Add(A, Mul(mp.fdiv(one, Neg(t1)), B))
    assert (Sub(Abs(a0), am) < epsilon
            )  # check if a0 is really below the bound
    assert (Sub(Abs(a1), am) < epsilon
            )  # check if a1 is really below the bound

    # import IPython; IPython.embed()

    # Check if the velocity bound is violated
    vp = Add(v0, Mul(a0, t0))
    if Abs(vp) > vm:
        vmnew = Mul(mp.sign(vp), vm)
        D2 = Prod([
            pointfive,
            Sqr(Sub(vp, vmnew)),
            Sub(mp.fdiv(one, a0), mp.fdiv(one, a1))
        ])
        # print "D2",
        # mp.nprint(D2, n=_prec)
        # print "vmnew",
        # mp.nprint(vmnew, n=_prec)
        A2 = Sqr(Sub(vmnew, v0))
        B2 = Neg(Sqr(Sub(vmnew, v1)))
        t0trimmed = mp.fdiv(Sub(vmnew, v0), a0)
        t1trimmed = mp.fdiv(Sub(v1, vmnew), a1)
        C2 = Sum([
            Mul(t0trimmed, Sub(vmnew, v0)),
            Mul(t1trimmed, Sub(vmnew, v1)),
            Mul(mp.mpf('-2'), D2)
        ])

        log.debug("\nA2 = {0}; \nB2 = {1}; \nC2 = {2}; \nD2 = {3};".format(
            mp.nstr(A2, n=_prec), mp.nstr(B2, n=_prec), mp.nstr(C2, n=_prec),
            mp.nstr(D2, n=_prec)))

        temp = Prod([A2, B2, B2])
        initguess = mp.sign(temp) * (Abs(temp)**(1. / 3.))
        root = mp.findroot(lambda x: Sub(Prod([x, x, x]), temp), x0=initguess)

        # import IPython; IPython.embed()
        log.debug("root = {0}".format(mp.nstr(root, n=_prec)))
        a0new = mp.fdiv(Add(A2, root), C2)
        if (Abs(a0new) > Add(am, epsilon)):
            if FuzzyZero(Sub(Mul(C2, a0new), A2), epsilon):
                # The computed a0new is exceeding the bound and its corresponding a1new is
                # zero. Therefore, there is no other way to fix this. This is probably because the
                # given newDuration is less than the minimum duration (x0, x1, v0, v1, vm, am) can
                # get.
                log.debug(
                    "abs(a0new) > am and a1new = 0; Cannot fix this case. This happens probably because the given newDuration is too short."
                )
                return ParabolicCurve()

            a0new = Mul(mp.sign(a0new), am)

        if (Abs(a0new) < epsilon):
            a1new = mp.fdiv(B2, C2)
            if (Abs(a1new) > Add(am, epsilon)):
                # Similar to the case above
                log.debug(
                    "a0new = 0 and abs(a1new) > am; Cannot fix this case. This happens probably because the given newDuration is too short."
                )
                return ParabolicCurve()

        else:
            if FuzzyZero(Sub(Mul(C2, a0new), A2), epsilon):
                # import IPython; IPython.embed()
                a1new = 0
            else:
                a1new = Mul(mp.fdiv(B2, C2),
                            Add(one, mp.fdiv(A2, Sub(Mul(C2, a0new), A2))))
                if (Abs(a1new) > Add(am, epsilon)):
                    a1new = Mul(mp.sign(a1new), am)
                    a0new = Mul(mp.fdiv(A2, C2),
                                Add(one, mp.fdiv(B2, Sub(Mul(C2, a1new), B2))))

        if (Abs(a0new) > Add(am, epsilon)) or (Abs(a1new) > Add(am, epsilon)):
            log.warn("Cannot fix acceleration bounds violation")
            return ParabolicCurve()

        log.debug(
            "\na0 = {0}; \na0new = {1}; \na1 = {2}; \na1new = {3};".format(
                mp.nstr(a0, n=_prec), mp.nstr(a0new, n=_prec),
                mp.nstr(a1, n=_prec), mp.nstr(a1new, n=_prec)))

        if (Abs(a0new) < epsilon) and (Abs(a1new) < epsilon):
            log.warn("Both accelerations are zero. Should we allow this case?")
            return ParabolicCurve()

        if (Abs(a0new) < epsilon):
            # This is likely because v0 is at the velocity bound
            t1new = mp.fdiv(Sub(v1, vmnew), a1new)
            assert (t1new > 0)
            ramp2 = Ramp(v0, a1new, t1new)

            t0new = Sub(newDuration, t1new)
            assert (t0new > 0)
            ramp1 = Ramp(v0, zero, t0new, x0)
            newCurve = ParabolicCurve([ramp1, ramp2])
            return newCurve

        elif (Abs(a1new) < epsilon):
            t0new = mp.fdiv(Sub(vmnew, v0), a0new)
            assert (t0new > 0)
            ramp1 = Ramp(v0, a0new, t0new, x0)

            t1new = Sub(newDuration, t0new)
            assert (t1new > 0)
            ramp2 = Ramp(ramp1.v1, zero, t1new)
            newCurve = ParabolicCurve([ramp1, ramp2])
            return newCurve

        else:
            # No problem with those new accelerations
            # import IPython; IPython.embed()
            t0new = mp.fdiv(Sub(vmnew, v0), a0new)
            if (t0new < 0):
                log.debug(
                    "t0new < 0. The given newDuration not achievable with the given bounds"
                )
                return ParabolicCurve()

            t1new = mp.fdiv(Sub(v1, vmnew), a1new)
            if (t1new < 0):
                log.debug(
                    "t1new < 0. The given newDuration not achievable with the given bounds"
                )
                return ParabolicCurve()

            if (Add(t0new, t1new) > newDuration):
                # Final fix. Since we give more weight to acceleration bounds, we make the velocity
                # bound saturated. Therefore, we set vp to vmnew.

                # import IPython; IPython.embed()
                if FuzzyZero(A, epsilon):
                    log.warn(
                        "(final fix) A is zero. Don't know how to fix this case"
                    )
                    return ParabolicCurve()

                t0new = mp.fdiv(Sub(Sub(vmnew, v0), B), A)
                if (t0new < 0):
                    log.debug("(final fix) t0new is negative")
                    return ParabolicCurve()

                t1new = Sub(newDuration, t0new)

                a0new = Add(A, Mul(mp.fdiv(one, t0new), B))
                a1new = Add(A, Mul(mp.fdiv(one, Neg(t1new)), B))
                ramp1 = Ramp(v0, a0new, t0new, x0)
                ramp2 = Ramp(ramp1.v1, a1new, t1new)
                newCurve = ParabolicCurve([ramp1, ramp2])

            else:
                ramp1 = Ramp(v0, a0new, t0new, x0)
                ramp3 = Ramp(ramp1.v1, a1new, t1new)
                ramp2 = Ramp(ramp1.v1, zero, Sub(newDuration,
                                                 Add(t0new, t1new)))
                newCurve = ParabolicCurve([ramp1, ramp2, ramp3])

                # import IPython; IPython.embed()

            return newCurve
    else:
        ramp1 = Ramp(v0, a0, t0, x0)
        ramp2 = Ramp(ramp1.v1, a1, t1)
        newCurve = ParabolicCurve([ramp1, ramp2])
        return newCurve