tune the drivetrain for this year's robot
Change-Id: I12aa734f4f09ce110faeb292fd0c9bfe08a46b2a
diff --git a/frc971/control_loops/python/drivetrain.py b/frc971/control_loops/python/drivetrain.py
index e2b42f5..8ed62d6 100755
--- a/frc971/control_loops/python/drivetrain.py
+++ b/frc971/control_loops/python/drivetrain.py
@@ -56,14 +56,14 @@
# Stall Torque in N m
self.stall_torque = 2.42
# Stall Current in Amps
- self.stall_current = 133
+ self.stall_current = 133.0
# Free Speed in RPM. Used number from last year.
self.free_speed = 4650.0
# Free Current in Amps
self.free_current = 2.7
# Moment of inertia of the drivetrain in kg m^2
# Just borrowed from last year.
- self.J = 4.5
+ self.J = 10
# Mass of the robot, in kg.
self.m = 68
# Radius of the robot, in meters (from last year).
@@ -71,7 +71,7 @@
# Radius of the wheels, in meters.
self.r = .0515938
# Resistance of the motor, divided by the number of motors.
- self.R = 12.0 / self.stall_current / 4
+ self.R = 12.0 / self.stall_current / 2
# Motor velocity constant
self.Kv = ((self.free_speed / 60.0 * 2.0 * numpy.pi) /
(12.0 - self.R * self.free_current))
diff --git a/frc971/control_loops/python/polydrivetrain.py b/frc971/control_loops/python/polydrivetrain.py
index 2b24396..a62c8c8 100755
--- a/frc971/control_loops/python/polydrivetrain.py
+++ b/frc971/control_loops/python/polydrivetrain.py
@@ -177,7 +177,7 @@
# ttrust is the comprimise between having full throttle negative inertia,
# and having no throttle negative inertia. A value of 0 is full throttle
# inertia. A value of 1 is no throttle negative inertia.
- self.ttrust = 1.0
+ self.ttrust = 1.1
self.left_gear = VelocityDrivetrain.LOW
self.right_gear = VelocityDrivetrain.LOW
@@ -302,26 +302,30 @@
# This is the same as sending the most torque down to the floor at the
# wheel.
- self.left_gear = self.ComputeGear(self.X[0, 0], should_print=True,
- current_gear=self.left_gear,
- gear_name="left")
- self.right_gear = self.ComputeGear(self.X[1, 0], should_print=True,
- current_gear=self.right_gear,
- gear_name="right")
- if self.IsInGear(self.left_gear):
- self.left_cim.X[0, 0] = self.MotorRPM(self.left_shifter_position, self.X[0, 0])
+ self.left_gear = self.right_gear = True
+ if False:
+ self.left_gear = self.ComputeGear(self.X[0, 0], should_print=True,
+ current_gear=self.left_gear,
+ gear_name="left")
+ self.right_gear = self.ComputeGear(self.X[1, 0], should_print=True,
+ current_gear=self.right_gear,
+ gear_name="right")
+ if self.IsInGear(self.left_gear):
+ self.left_cim.X[0, 0] = self.MotorRPM(self.left_shifter_position, self.X[0, 0])
- if self.IsInGear(self.right_gear):
- self.right_cim.X[0, 0] = self.MotorRPM(self.right_shifter_position, self.X[0, 0])
+ if self.IsInGear(self.right_gear):
+ self.right_cim.X[0, 0] = self.MotorRPM(self.right_shifter_position, self.X[0, 0])
- if self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
+ steering *= 2.3
+ if True or self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
# Filter the throttle to provide a nicer response.
fvel = self.FilterVelocity(throttle)
# Constant radius means that angualar_velocity / linear_velocity = constant.
# Compute the left and right velocities.
- left_velocity = fvel - steering * numpy.abs(fvel)
- right_velocity = fvel + steering * numpy.abs(fvel)
+ steering_velocity = numpy.abs(fvel) * steering
+ left_velocity = fvel - steering_velocity
+ right_velocity = fvel + steering_velocity
# Write this constraint in the form of K * R = w
# angular velocity / linear velocity = constant
@@ -379,7 +383,7 @@
# TODO(austin): Model the robot as not accelerating when you shift...
# This hack only works when you shift at the same time.
- if self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
+ if True or self.IsInGear(self.left_gear) and self.IsInGear(self.right_gear):
self.X = self.CurrentDrivetrain().A * self.X + self.CurrentDrivetrain().B * self.U
self.left_gear, self.left_shifter_position = self.SimShifter(
@@ -441,13 +445,13 @@
else:
print "Right is low"
- for t in numpy.arange(0, 4.0, vdrivetrain.dt):
- if t < 1.0:
- vdrivetrain.Update(throttle=1.00, steering=0.0)
+ for t in numpy.arange(0, 1.7, vdrivetrain.dt):
+ if t < 0.5:
+ vdrivetrain.Update(throttle=0.00, steering=1.0)
elif t < 1.2:
- vdrivetrain.Update(throttle=1.00, steering=0.0)
+ vdrivetrain.Update(throttle=0.5, steering=1.0)
else:
- vdrivetrain.Update(throttle=1.00, steering=0.0)
+ vdrivetrain.Update(throttle=0.00, steering=1.0)
t_plot.append(t)
vl_plot.append(vdrivetrain.X[0, 0])
vr_plot.append(vdrivetrain.X[1, 0])
@@ -474,10 +478,10 @@
cim_velocity_plot.append(cim.X[0, 0])
cim_voltage_plot.append(U[0, 0] * 10)
cim_time.append(t)
- #pylab.plot(cim_time, cim_velocity_plot, label='cim spinup')
- #pylab.plot(cim_time, cim_voltage_plot, label='cim voltage')
- #pylab.legend()
- #pylab.show()
+ pylab.plot(cim_time, cim_velocity_plot, label='cim spinup')
+ pylab.plot(cim_time, cim_voltage_plot, label='cim voltage')
+ pylab.legend()
+ pylab.show()
# TODO(austin):
# Shifting compensation.