Indoor positioning and navigation systems and methods
Indoors positioning and navigation systems and methods are described herein. In one embodiment, a system for inspecting or maintaining a storage tank includes a vehicle having: at least one sensor for determining properties of a storage tank and a navigation system. The navigation system includes an acoustic transmitter carried by the vehicle and an inertial measurement unit (IMU) sensor configured to at least partially determine a location of the vehicle with respect to the storage tank. The vehicle also includes a propulsion unit configured to move the vehicle within the storage tank, and an acoustic receiver fixed with respect to the storage tank. The vehicle moves inside the storage tank in concentric arcs with respect to the acoustic receiver.
1. A system for inspecting or maintaining a storage tank, comprising:
a vehicle comprising:
at least one sensor for determining properties of a storage tank;
a navigation system comprising:
an acoustic transmitter (TX) carried by the vehicle, and a propulsion unit configured to move the vehicle within the storage tank; and
an acoustic receiver (RX) fixed with respect to the storage tank, wherein the vehicle moves inside the storage tank in concentric arcs with respect to the acoustic receiver (RX) being a center point of the concentric arcs.
2. The system of claim 1 , wherein the TX is an acoustic pinger, and the RX is a hydrophone.
3. The system of claim 1 , wherein the RX is a bright acoustic reflector inside the storage tank.
4. The system of claim 3 , wherein the bright acoustic reflector inside the storage tank is an acoustic retroreflector string or a corner acoustic reflector.
5. The system of claim 4 , wherein a shape of the bright acoustic reflector is selected from a group consisting of a trihedral topology, an octahedral topology, a star topology, a cross topology and an offset-cross topology.
6. The system of claim 1 , further comprising a second RX fixed with respect to the storage tank, wherein the vehicle at least partially moves inside the storage tank in another set of concentric arcs with respect to the second RX.
7. The system of claim 1 , wherein the at least one sensor for determining properties of the storage tank is configured to determine thickness of a tank wall or a tank floor.
8. The system of claim 7 , wherein the at least one sensor for determining properties of the storage tank is an ultrasound sensor or an electromagnetic sensor.
9. The system of claim 1 , wherein the vehicle is a remotely operated vehicle (ROV) or an autonomously operated vehicle.
10. The system of claim 9 , wherein the navigation system of the ROV further comprises a sensor selected from a group consisting of: a hydrostatic pressure sensor configured for depth measurements, and an optical ranging system.
11. The system of claim 10 , wherein the optical ranging system is a lidar.
12. A method for inspecting or maintaining a storage tank, comprising:
positioning a vehicle at a first location inside the storage tank by a propulsion unit of the vehicle, the vehicle comprising at least one acoustic receiver (RX), at least one acoustic transmitter (TX), at least one inertial measurement unit (IMU);
emitting, by the at least one TX of the vehicle, a first acoustic signal toward an acoustic hydrophone attached to the storage tank in a first location;
determining a distance from the at least one TX of the vehicle to the acoustic hydrophone attached to the storage tank;
emitting, by the at least one TX of the vehicle, a second acoustic signal toward a bright acoustic reflector attached to the storage tank in a second location;
receiving, by the at least one RX of the vehicle, a second reflected acoustic signal from the bright acoustic reflector;
determining a first azimuth angle of the vehicle with respect to a longitudinal axis of the vehicle and a first distance from the bright acoustic reflector;
moving the vehicle in a direction of an azimuth direction to a second location of the vehicle inside the storage tank; and
determining a second azimuth angle of the vehicle at the second location with respect to a second distance from the acoustic hydrophone and a second distance from the bright acoustic reflector.
13. The method of claim 12 , further comprising moving the vehicle to a third location along a straight line through the first location and the second location.
14. The method of claim 12 , further comprising sensing a property of the storage tank at the first location by at least one sensor of the vehicle.
15. The method of claim 12 , wherein the vehicle is a remotely operated vehicle (ROV) or an autonomously operated vehicle.
16. The method of claim 15 , wherein the RX, the TX, and the IMU of the vehicle are elements of a navigation system of the ROV, the navigation system further comprising at least one sensor selected from a group consisting of: a hydrostatic pressure sensor configured for depth measurements, and an optical ranging system.
17. The method of claim 12 , further comprising verifying that the second azimuth angle corresponds to the second location of the vehicle as determined based on the at least one IMU and at least one encoder.
18. The method of claim 12 , further comprising determining the second location of the vehicle based on the at least one IMU and at least one encoder.
19. A method for inspecting or maintaining a storage tank, comprising:
traversing a vehicle inside the storage tank;
determining properties of a storage tank by at least one sensor of the vehicle;
navigating the vehicle by a navigation system comprising:
an acoustic transmitter (TX) carried by the vehicle, an inertial measurement unit (IMU) sensor configured to at least partially determine a location of the vehicle with respect to the storage tank, and a propulsion unit configured to move the vehicle within the storage tank; and
sending acoustic signal by the TX carried by the vehicle to an acoustic receiver (RX) fixed with respect to the storage tank, wherein the vehicle moves inside the storage tank in concentric arcs with respect to the RX fixed with respect to the storage tank, wherein the RX is a center point of the concentric arcs.
20. The method of claim 19 , further comprising sending acoustic signal by the TX carried by the vehicle to a second RX fixed with respect to the storage tank, wherein the vehicle at least partially moves inside the storage tank in another set of concentric arcs with respect to the second RX.
21. The method of claim 19 , wherein the TX is an acoustic pinger, and the RX is a hydrophone.
22. The method of claim 19 , wherein the RX is a bright acoustic reflector inside the storage tank.
23. The method of claim 19 , wherein the bright acoustic reflector inside the storage tank is an acoustic retroreflector string or a corner acoustic reflector.
24. A system for inspecting or maintaining a storage tank, comprising:
a vehicle comprising:
a propulsion unit configured to move the vehicle within the storage tank;
at least one sensor for determining properties of the storage tank;
at least one inertial measurement unit (IMU) sensor configured to at least partially determine a location of the vehicle with respect to the storage tank;
at least one acoustic transmitter (TX) carried by the vehicle; and
at least acoustic receiver (RX) carried by the vehicle;
an acoustic hydrophone attached to the storage tank in a first location; and
a bright acoustic reflector attached to the storage tank in a second location, wherein the system comprises a non-transitory computer-readable medium having computer-executable instructions stored thereon that, in response to execution by one or more processors of a computing device, cause the computing device to perform actions comprising:
positioning the vehicle at a first location inside the storage tank by the propulsion unit of the vehicle, the vehicle comprising at least one inertial measurement unit (IMU);
emitting by the at least one TX of the vehicle, a first acoustic signal toward an acoustic hydrophone attached to the storage tank in a first location;
determining a distance from the at least one TX of the vehicle to the acoustic hydrophone attached to the storage tank;
emitting, by the at least one TX of the vehicle, a second acoustic signal toward a bright acoustic reflector attached to the storage tank in a second location;
receiving, by the at least one RX of the vehicle, a second reflected acoustic signal from the bright acoustic reflector;
determining a first azimuth angle of the vehicle with respect to a longitudinal axis of the vehicle and a first distance from the bright acoustic reflector;
moving the vehicle in a direction of an azimuth direction to a second location of the vehicle inside the storage tank; and
determining a second azimuth angle of the vehicle at the second location with respect to a second distance from the acoustic hydrophone and a second distance from the bright acoustic reflector.
25. The system of claim 24 , wherein the computer-executable instructions further cause the computing device to perform actions comprising moving the vehicle to a third location along a straight line through the first location and the second location.
26. The system of claim 24 , wherein the computer-executable instructions further cause the computing device to perform actions comprising sensing a property of the storage tank at the first location by at least one sensor of the vehicle.
27. The system of claim 24 , wherein the vehicle is a remotely operated vehicle (ROV) or an autonomously operated vehicle.
28. The system of claim 24 , wherein the RX, the TX, the IMU and at least one encoder of the vehicle are elements of a navigation system of the ROV, the navigation system further comprising at least one sensor selected from a group consisting of: a hydrostatic pressure sensor configured for depth measurements, and an optical ranging system.
29. The system of claim 24 , wherein the computer-executable instructions further cause the computing device to perform actions comprising further comprising:
verifying that the second azimuth angle corresponds to the second location of the vehicle as determined based on the at least one IMU and at least one encoder.
30. The system of claim 24 , further comprising determining the second location of the vehicle based on the at least one IMU and at least one encoder.