def step(self, pt):
"""Measure one point and return (time, z-value)."""
a3200.xymove(pt, velocity=600, blocking=True)
z = keyence.measure(blocking=True)
if self.gantry and z:
z -= self.gantry.error(pt)
return (time.time(), z if z else numpy.nan)
def find_center(radius=4000):
keyence.set_samples(4, 1)
path = follow_edge(.04)
a3200.xymove(numpy.average(path, 0))
a3200.z.enable()
a3200.z.relmove(-radius)
a3200.z.disable()
spiral_search((lambda: keyence.measure() is None), 0.005)
spiral_search((lambda: abs(keyence.measure(1) - keyence.measure(2) < 10)), 0.001)
def follow_edge(step=1):
a3200.x.freerun(1)
while keyence.measure() is not None: time.sleep(.01)
a3200.x.halt()
a3200.x.relmove(-step/2)
origin, xy = a3200.xyposition(), numpy.array([0, 0])
heading, path, i, dark = 0, [], 0, False
while tuple(xy) not in path[:-10]:
ldark, dark = dark, (keyence.measure(blocking=True) is None)
if dark != ldark: i = 0
if i%2 or not i: heading = (heading + (-1 if dark else 1)) % 4
xy += [(1,0),(0,1),(-1,0),(0,-1)][heading]
a3200.xymove(origin + xy*step)
path.append(tuple(xy))
i += 1
return origin + numpy.array(path, dtype='float')*step
def value_and_gradient(pt, func, step=.05):
x, y = pt
a3200.xymove((x, y+step), blocking=True)
f_y = func()
a3200.xymove((x, y), blocking=True)
f_0 = func()
a3200.xymove((x+step, y), blocking=True)
f_x = func()
return f_0, [(f_x-f_0)/step, (f_y-f_0)/step]
def spiral_search(continue_func, step=.01):
p0 = a3200.xyposition()
s = spiral()
while continue_func():
a3200.xymove(p0+numpy.array(next(s))*step, blocking=True)
