Hover script

The trick is that the throttle is higher when falling than when rising

hover.py

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+#! /bin/python3
+# Hover vessel
+import time
+import krpc
+
+# Target altitude in meters
+target_altitude = 100
+
+# The IP of the KRPC server (if not same computer)
+remote = '192.168.1.10'
+# Make connection
+conn = krpc.connect(name='Hover', address=remote)
+
+# Important objects
+vessel = conn.space_center.active_vessel
+body = vessel.orbit.body
+r_frame = body.reference_frame
+print(vessel.name)
+
+vessel.control.throttle = 0.0
+vessel.control.activate_next_stage()
+
+grav = body.surface_gravity
+at = vessel.available_thrust
+
+vessel.control.legs = False
+vessel.auto_pilot.target_pitch_and_heading(90, 90)
+vessel.auto_pilot.engage()
+timepoint = 0
+
+print('timepoint, current_altitude, v_speed, mass, minviable')
+while at > 0:
+    vm = vessel.mass
+    minviable = (vm * grav) / at
+    current_altitude = vessel.flight(r_frame).surface_altitude
+    v_speed = vessel.flight(r_frame).vertical_speed
+    print(timepoint, current_altitude, v_speed, vm, minviable, sep=',')
+    if current_altitude > target_altitude:
+        if v_speed < 0:
+            vessel.control.throttle = minviable * 0.6
+        else:
+            vessel.control.throttle = 0
+    else:
+        if v_speed > 0:
+            vessel.control.throttle = (2 - ((current_altitude + 20) /
+                                            (target_altitude + 20))) * minviable
+        else:
+            vessel.control.throttle = (3 - (current_altitude / target_altitude)) * minviable
+    time.sleep(0.1)
+    at = vessel.available_thrust
+    timepoint = timepoint + 1
+
+conn.close()