mirror of https://github.com/ArduPilot/ardupilot
147 lines
4.8 KiB
Python
147 lines
4.8 KiB
Python
#!/usr/bin/env python
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'''
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simple antenna tracker simulator core
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'''
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from aircraft import Aircraft
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import util, time, math
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from math import degrees, radians
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from rotmat import Vector3
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class Tracker(Aircraft):
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'''a simple antenna tracker'''
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def __init__(self,
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onoff=False,
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yawrate=9.0,
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pitchrate=1.0,
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pitch_range = 45,
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yaw_range = 170,
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zero_yaw = 270, # yaw direction at startup
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zero_pitch = 10 # pitch at startup
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):
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Aircraft.__init__(self)
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self.onoff = onoff
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self.yawrate = yawrate
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self.pitchrate = pitchrate
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self.last_time = time.time()
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self.pitch_range = pitch_range
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self.yaw_range = yaw_range
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self.zero_yaw = zero_yaw
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self.zero_pitch = zero_pitch
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self.verbose = False
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self.last_debug = time.time()
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self.pitch_current = 0
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self.yaw_current = 0
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def slew_limit(self, current, target, range, delta_time, turn_rate):
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'''limit speed of servo movement'''
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dangle = turn_rate * delta_time
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dv = dangle / range
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if target - current > dv:
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return current + dv
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if target - current < -dv:
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return current - dv
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return target
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def update_position_servos(self, state, delta_time):
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'''update function for position (normal) servos.
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Returns (yaw_rate,pitch_rate) tuple'''
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self.pitch_current = self.slew_limit(self.pitch_current, state.pitch_input, self.pitch_range, delta_time, self.yawrate)
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self.yaw_current = self.slew_limit(self.yaw_current, state.yaw_input, self.yaw_range, delta_time, self.pitchrate)
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pitch_target = self.zero_pitch + self.pitch_current*self.pitch_range
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yaw_target = self.zero_yaw + self.yaw_current*self.yaw_range
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while yaw_target > 180:
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yaw_target -= 360
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(r,p,y) = self.dcm.to_euler()
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pitch_current = degrees(p)
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yaw_current = degrees(y)
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roll_current = degrees(r)
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pitch_rate = pitch_target - pitch_current
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pitch_rate = min(self.pitchrate, pitch_rate)
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pitch_rate = max(-self.pitchrate, pitch_rate)
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yaw_diff = yaw_target - yaw_current
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if yaw_diff > 180:
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yaw_diff -= 360
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if yaw_diff < -180:
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yaw_diff += 360
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yaw_rate = yaw_diff
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yaw_rate = min(self.yawrate, yaw_rate)
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yaw_rate = max(-self.yawrate, yaw_rate)
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return (yaw_rate, pitch_rate)
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def update_onoff_servos(self, state):
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'''update function for onoff servos.
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These servos either move at a constant rate or are still
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Returns (yaw_rate,pitch_rate) tuple'''
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if abs(state.yaw_input) < 0.1:
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yaw_rate = 0
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elif state.yaw_input >= 0.1:
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yaw_rate = self.yawrate
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else:
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yaw_rate = -self.yawrate
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if abs(state.pitch_input) < 0.1:
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pitch_rate = 0
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elif state.pitch_input >= 0.1:
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pitch_rate = self.pitchrate
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else:
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pitch_rate = -self.pitchrate
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return (yaw_rate, pitch_rate)
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def update(self, state):
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# how much time has passed?
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t = time.time()
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delta_time = t - self.last_time
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self.last_time = t
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if self.onoff:
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(yaw_rate,pitch_rate) = self.update_onoff_servos(state)
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else:
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(yaw_rate,pitch_rate) = self.update_position_servos(state, delta_time)
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# implement yaw and pitch limits
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(r,p,y) = self.dcm.to_euler()
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pitch_current = degrees(p)
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yaw_current = degrees(y)
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roll_current = degrees(r)
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if yaw_rate > 0 and yaw_current >= self.yaw_range:
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yaw_rate = 0
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if yaw_rate < 0 and yaw_current <= -self.yaw_range:
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yaw_rate = 0
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if pitch_rate > 0 and pitch_current >= self.pitch_range:
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pitch_rate = 0
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if pitch_rate < 0 and pitch_current <= -self.pitch_range:
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pitch_rate = 0
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# keep it level
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roll_rate = 0 - roll_current
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if time.time() - self.last_debug > 2 and not self.onoff:
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self.last_debug = time.time()
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print("roll=%.1f/%.1f pitch=%.1f yaw=%.1f rates=%.1f/%.1f/%.1f" % (
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roll_current, 0,
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pitch_current,
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yaw_current,
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roll_rate, pitch_rate, yaw_rate))
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self.gyro = Vector3(radians(roll_rate),radians(pitch_rate),radians(yaw_rate))
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# update attitude
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self.dcm.rotate(self.gyro * delta_time)
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self.dcm.normalize()
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accel_earth = Vector3(0, 0, -self.gravity)
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self.accel_body = self.dcm.transposed() * accel_earth
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# new velocity vector
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self.velocity = Vector3()
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self.update_position()
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