The EvoLogics Sonobot is an autonomous unmanned surface vehicle (ASV) designed for hydrographic surveys. It is a catamaran-type vessel, meaning it has twin hulls, which provide stability and house the batteries and integrated hydro-jet thrusters. The main body of the Sonobot, containing the on-board equipment, is mounted on crossbars that connect to the floaters. The system is designed for effortless, no-tool assembly, with eccentric latches securing the main body, crossbars, and floaters.
Function Description:
The Sonobot's primary function is to conduct hydrographic surveys autonomously. It achieves this by precisely driving in an operating area to collect measurement data, which can include single-beam echosounder data and side-scan sonar data, depending on the configuration. The mission plan, defining the vehicle's route, can be repeated as often as needed to monitor changes in the survey area over time.
The on-board equipment, which varies by configuration, typically includes:
- Differential GPS system: For accurate positioning and navigation.
- Single-beam echosounder: For depth measurements.
- Side-scan sonar: For detailed seafloor imaging.
- Wireless communication system: For data transfer and remote control.
- Radio control system: For manual steering and emergency override.
- Autopilot: For autonomous mission execution.
- On-board PC: To run control software and store data.
The shore equipment complements the ASV and includes:
- Wireless LAN station: A WLAN box with an antenna on a tripod, providing wireless communication with the Sonobot.
- Field PC: A rugged laptop (Durabook® U14M) running Windows XP, used for mission planning, monitoring, and data management.
- Radio control unit: For manual control of the Sonobot.
- Transport boxes: Two boxes for safe transportation of the system components.
- Battery chargers: Three chargers for the various battery packs.
- Connection cables: For WLAN antenna and Ethernet connection to the field PC.
Important Technical Specifications:
- Vehicle Type: Autonomous Unmanned Surface Vehicle (ASV), catamaran-type.
- Propulsion: Integrated hydro-jet thrusters.
- Assembly: No-tool assembly with eccentric latches.
- On-board PC: Runs Sonobot_2 software for monitoring and data acquisition.
- Field PC: Durabook® U14M semi-rugged laptop, Windows XP, runs Horizonmp (autopilot control) and Radmin Viewer (vehicle access) software.
- Communication: Wireless LAN for data transfer and control; radio control for manual operation.
- Echosounder Depth Ranges: Configurable to 0.5 - 2 m, 1 - 15 m, or 12 - 45 m.
- Operating Speed: Best operated at 4 km/h (2.2 kn) for optimal measurement accuracy and propulsion speed balance.
- Environmental Conditions: Operable under up to 3 Bft (3.4-5.4 m/s) wind and 0.3 m wave conditions. Not recommended for winds stronger than 3 Bft or waves higher than 0.3 m.
- Battery Voltage (Critical): Mission must stop for recharge if any battery pack drops to 13 V. Power is shut off automatically at 11 V.
Usage Features:
- Mission Planning (Horizonmp software):
- Allows defining waypoints for autonomous navigation.
- Supports georeferenced maps of the operating area.
- Enables creation of survey grids within defined perimeters.
- Waypoint files can be transmitted wirelessly to the Sonobot's autopilot.
- Vehicle Access (Radmin Viewer):
- Provides full control and monitoring of the Sonobot's on-board PC from the field PC.
- Allows file transfer for downloading measurement data during missions.
- Echosounder Control (Sonobot_2 software):
- Displays real-time status of the vehicle's systems, including battery voltages (propulsion and payload).
- Configures echosounder settings like depth range, Time Gain Compensation (TGC), measurement period, and detection threshold.
- Provides visual representation of echo-sounder measurements (echo waveform and time-depth plot).
- Allows starting and stopping depth data acquisition and saving to log files.
- Side-Scan Sonar Control (DeepView software):
- Records and reviews side-scan sonar files.
- Provides real-time representation of side-scan sonar, echosounder, and GPS data.
- Offers 3D overview of measurements and data export to Google Earth.
- Allows starting and stopping side-scan sonar data recording.
- Remote Control:
- Used for manual steering, system check-ups, and emergency override.
- Left stick controls steering (left/right) and gas (forward/backward).
- Right stick controls constant speed.
- Autopilot/Manual switch (6) toggles between control modes.
- Must be on and in Manual mode before connecting to the autopilot.
- Autonomous Operation:
- The autopilot drives the vehicle along programmed waypoints, correcting for wind or current drift.
- Operating speed can be adjusted during missions.
- Vehicle can be commanded to "Go Home" to return to its initialization point.
- Waypoints can be dragged to new positions during a mission (though changes are not saved to the mission file).
Maintenance Features:
- Battery Management:
- Three battery chargers are supplied for payload, propulsion, and WLAN box batteries.
- Batteries can be charged while still inside the vehicle.
- Crucial to monitor battery voltage (via Sonobot_2 Status tab or WLAN box button) and recharge if voltage drops to 13 V to prevent damage and automatic shutdown.
- Avoid short circuits and mechanical damage to batteries.
- Only use original chargers.
- Charging should not be left unattended.
- Avoid storing fully charged batteries for long periods; half-charge is recommended.
- Thruster Care:
- Perform on-shore and afloat tests of the propulsion system at lowest thrust to avoid overheating bearings and seals.
- Exercise caution to prevent debris or dirt from being sucked into the thrusters.
- Avoid areas covered in debris or vegetation during missions.
- Have a recovery boat on hand in case thrusters become clogged.
- Echosounder Calibration:
- Calibrate the echosounder by comparing its depth readings with manual measurements (e.g., lead line) in shallow water.
- Adjust the sound velocity value in the Echosounder tab to match observed actual depth.
- Automatic depth range recognition can be enabled after initial measurements.
- Software Management:
- Ensure service programs (hub4com_startup and serial2.py) are running on the on-board PC for correct vehicle operation. Relaunch via desktop shortcuts if accidentally closed.
- Do not change settings in the Sonobot_2 Advanced tab without consulting EvoLogics.
- Physical Handling:
- When handling the vehicle, avoid mechanical damage to side-scan sonar antennas.
- Ensure the WLAN antenna is upright, facing the operating area, and free of obstacles for optimal signal reception. The tripod should be stable enough to withstand wind gusts.
Need help?
To Next Page
General