# Strange Turbulent Flight Behavior when transitioning into Offboard Mode (Please Help!!) Source: https://forum.modalai.com/topic/3339/strange-turbulent-flight-behavior-when-transitioning-into-offboard-mode-please-help Category: General Questions (https://forum.modalai.com/category/2/general-questions) Posted: 2024-04-17 19:18:09 UTC by ggiacalone Replies: 2 · Views: 725 ## ggiacalone · 2024-04-17 19:18:09 UTC I am attempting to use my Sentinel drone with offboard control and I am running into some undesirable behaviors. Here is a video that shows the behavior: https://www.youtube.com/watch?v=NoKqImDZU4A This is the code I am running from my laptop while running the Mavros node on the Voxl 2. ``` #! /usr/bin/env python import rospy from geometry_msgs.msg import PoseStamped from mavros_msgs.msg import State from mavros_msgs.srv import CommandBool, CommandBoolRequest, SetMode, SetModeRequest current_state = State() def state_cb(msg): global current_state current_state = msg if __name__ == "__main__": rospy.init_node("offb_node_py") state_sub = rospy.Subscriber("mavros/state", State, callback = state_cb) local_pos_pub = rospy.Publisher("mavros/setpoint_position/local", PoseStamped, queue_size=10) rospy.wait_for_service("/mavros/cmd/arming") arming_client = rospy.ServiceProxy("mavros/cmd/arming", CommandBool) rospy.wait_for_service("/mavros/set_mode") set_mode_client = rospy.ServiceProxy("mavros/set_mode", SetMode) # Setpoint publishing MUST be faster than 2Hz rate = rospy.Rate(20) # Wait for Flight Controller connection while(not rospy.is_shutdown() and not current_state.connected): rate.sleep() initial_pose = PoseStamped() initial_pose.pose.position.x = 0 initial_pose.pose.position.y = 0 initial_pose.pose.position.z = 1.3 initial_pose.pose.orientation.x = 0.0 initial_pose.pose.orientation.y = 0.0 initial_pose.pose.orientation.z = -0.7071 initial_pose.pose.orientation.w = -0.7071 land_pose = PoseStamped() land_pose.pose.position.x = 0 land_pose.pose.position.y = 0 land_pose.pose.position.z = 0 land_pose.pose.orientation.x = 0.0 land_pose.pose.orientation.y = 0.0 land_pose.pose.orientation.z = -0.7071 land_pose.pose.orientation.w = -0.7071 flight_over = False # Variable to hold control timing for simple hop test # TODO replace with better controll later control_time_start = None # Send a few setpoints before starting for i in range(100): if(rospy.is_shutdown()): break local_pos_pub.publish(initial_pose) rate.sleep() offb_set_mode = SetModeRequest() offb_set_mode.custom_mode = 'OFFBOARD' arm_cmd = CommandBoolRequest() arm_cmd.value = True disarm_cmd = CommandBoolRequest() disarm_cmd.value = False last_req = rospy.Time.now() while(not rospy.is_shutdown()): if control_time_start is None: control_time_start = rospy.Time.now() if(current_state.mode != "OFFBOARD" and (rospy.Time.now() - last_req) > rospy.Duration(5.0)): if(set_mode_client.call(offb_set_mode).mode_sent == True): rospy.loginfo("OFFBOARD enabled") last_req = rospy.Time.now() else: if(not current_state.armed and (rospy.Time.now() - last_req) > rospy.Duration(5.0) and not flight_over): if(arming_client.call(arm_cmd).success == True): rospy.loginfo("Vehicle armed") last_req = rospy.Time.now() # Time Based Control for Hop Routine # TODO Make better later if (rospy.Time.now() - control_time_start) < rospy.Duration(15.0): local_pos_pub.publish(initial_pose) elif (rospy.Time.now() - control_time_start) < rospy.Duration(15.5): local_pos_pub.publish(land_pose) else: # Disarm the drone if(current_state.armed and (rospy.Time.now() - last_req) > rospy.Duration(5.0)): if(arming_client.call(disarm_cmd).success == True): rospy.loginfo("Vehicle Disarmed") last_req = rospy.Time.now() flight_over = True rate.sleep() ``` I am using this mavros code to control it to go to a predefined setpoint. Unfortunately, on the first flight of every power cycle, it has a little bit of turbulence and it bounces up and down and shakes in the air a little bit before quickly and accurately moving to the desired setpoint I commanded it to go to. If the flight finishes and I run the code on my computer again to rerun the flight, it executes perfectly with no oscillations or other issues. It almost looks like the drone is fighting with itself until it makes it's mind up about where it needs to go. I also noticed that every time the drone powercycles, it thinks that its initial /mavros/local_position_pose has an orientation of approximately ``` initial_pose.pose.orientation.x = 0.0 initial_pose.pose.orientation.y = 0.0 initial_pose.pose.orientation.z = -0.7071 initial_pose.pose.orientation.w = -0.7071 ``` hence why I ensure to include this point in my setpoint pose. Although, QVIO shows the correct "zeroed" pose. Again, everytime I re run the code without turning the drone off and powering on again, it goes straight to the setpoint without any turbulence or shaking (except for the first flight) which makes me believe it's not an issue with the code. Why might it be having this unexpected and unwelcomed behavior? -------------------------------------------------------------------------------- system-image: 1.7.4-M0054-14.1a-perf kernel: #1 SMP PREEMPT Fri Feb 9 21:59:24 UTC 2024 4.19.125 -------------------------------------------------------------------------------- hw platform: M0054 mach.var: 1.0 -------------------------------------------------------------------------------- voxl-suite: 1.1.3-1 -------------------------------------------------------------------------------- Service Name | Enabled | Running | CPU Usage ------------------------------------------------------------------- docker-autorun | Disabled | Not Running | modallink-relink | Disabled | Not Running | voxl-camera-server | Enabled | Running | 78.6% voxl-cpu-monitor | Enabled | Running | 0.6% voxl-dfs-server | Enabled | Running | 23.5% voxl-feature-tracker | Disabled | Not Running | voxl-flow-server | Disabled | Not Running | voxl-imu-server | Enabled | Running | 5.7% voxl-lepton-server | Disabled | Not Running | voxl-mapper | Enabled | Running | 0.7% voxl-mavcam-manager | Enabled | Running | 0.0% voxl-mavlink-server | Enabled | Running | 3.4% voxl-modem | Disabled | Not Running | voxl-neopixel-manager | Disabled | Not Running | voxl-open-vins-server | Disabled | Not Running | voxl-portal | Enabled | Running | 0.2% voxl-px4-imu-server | Disabled | Not Running | voxl-px4 | Enabled | Running | 38.7% voxl-qvio-server | Enabled | Running | 15.4% voxl-rangefinder-server | Disabled | Not Running | voxl-remote-id | Disabled | Not Running | voxl-softap | Disabled | Not Running | voxl-static-ip | Disabled | Not Running | voxl-streamer | Enabled | Running | 0.0% voxl-tag-detector | Disabled | Not Running | voxl-tflite-server | Disabled | Not Running | voxl-time-sync | Disabled | Not Running | voxl-uvc-server | Disabled | Not Running | voxl-vision-hub | Enabled | Running | 11.3% voxl-wait-for-fs | Enabled | Completed | ``` ## Reply by Dawid Mościcki · 2024-04-18 08:47:42 UTC In my case similar behavior was fixed by : "The thing that is most likely the issue I believe is voxl-vision-hub. There is a program in vision-hub that will automatically do a figure 8 in offboard when it gets kicked off programatically and this is most likely conflicting with your takeoff. The parameters you needs to disable in /etc/modalai/voxl-vision-hub.conf are: offboard_mode: off" ## Reply by ggiacalone · 2024-04-18 22:44:36 UTC (in reply to Dawid Mościcki) @Dawid-Mościcki Wow amazing I will give this a try very soon. Thank you so much!