Test method and system for dynamic positioning systems

• US 7,818,103 B2
• Filed: 04/04/2005
• Issued: 10/19/2010
• Est. Priority Date: 11/19/2004
• Status: Expired due to Fees

• Current Assignee: Marine Cybernetics AS (Stiftelsen Det Norske Veritas)
• Original Assignee: Marine Cybernetics AS (Stiftelsen Det Norske Veritas)
• Inventors: Skjetne, Roger, Johansen, Tor Arne, Sorensen, Asgeir Johan
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): JEN, MINGJEN
• Application Number:
  US11/097,382
• Publication Number:
  US 20060111855A1
• Time in Patent Office: 2,024 Days
• Field of Search: 702/67, 701/21, 701/224
• US Class Current: 701/22
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles

Abstract

A test system and method for a marine vessel dynamic positioning system comprising a control system (2) arranged for receiving real measurement signals (7) from sensors (8) and for output of control signals (13) to actuators (16, 17, 18). The test system comprises a signal modifying computer (80) arranged for receiving real measurement signals (7), modifying the real measurement signals (7) into modified measurement signals (70) that depend on real values of the real measurement signals (7), and sending the modified measurement signals (70) to the control system (2), wherein the modified measurement signals (70) replaces the real measurement signals (7), so as for enabling testing of the control system (2) on errors represented by the modified measurement signals (70).

Claims

1. A test system for a marine vessel dynamic positioning system, wherein said dynamic positioning system comprises actuators (16, 17, 18), sensors (8), and a control system (2), said control system arranged for receiving real measurement signals (7) from sensors (8) and for output of control signals (13) to said actuators (16, 17, 18), said test system comprising

a signal modifying computer (80) arranged for:

receiving one or more of said real measurement signals (7),

modifying said one or more real measurement signals (7) into modified measurement signals (70) that depend on real values of said real measurement signals;

sending said modified measurement signals (70) to said control system (2), wherein said modified measurement signal (70) replaces one or more of said real measurement signals(7);

said control system (2) arranged for acting upon said one or more modified measurement signals (70) and remaining unaffected real measurement signals (7);

wherein said signal modifying computer enables testing of said control system (2) function on errors represented by said modified measurement signals (70) imagined to occur in one or more sensors (8).

2. The test system of claim 1, said marine control system (2) arranged for receiving input command signals (9) from a command input device (10) on a command signal line (11).

3. The test system of claim 1, said sensors (8) connected to said control system using a sensor signal line (12).

4. The test system of claim 3, said sensor signal line (12) comprising an analog line, a serial line, or a digital Ethernet line, a fieldbus or CAN-bus, or a local radio communication system.

5. The test system of claim 1, arranged for outputting control signals (13) to said actuators (16, 17, 18), like propellers (16), thrusters (17), and rudders (18).

6. The test system of claim 1, said signal modifying computer (80) being arranged for modifying said real measurement signals (7) in a relatively short time into modified measurement signals (70), so as for said control system (2) experiencing no significant delay of said modified measurement signals (70) as compared to the corresponding reception time said control system (2) would have received said real measurement signals (7).

7. The test system of claim 1, said control system (2) comprising a power management system including power sensors (8p) for sensing power signals like generator output voltage (7pV), generator output current (7pA), generator power (7pP), fractional total generator power (7pTf), generator status (7pS), and the like.

8. The test system of claim 1, said marine control system (2) arranged for receiving input command signals (9) from a command input device (10) on a command signal line (11).

9. A method for testing a marine vessel dynamic positioning system, wherein said dynamic positioning system comprises actuators (16, 17, 18), sensors (8), and a control system (2), said control system (2) receiving real measurement signals (7) from said sensors (8) and providing control signals (13) to said actuators (16, 17, 18), said method comprising the following steps:

connecting a signal modifying computer (80) for receiving one or more of said real measurement signals (7),

modifying said real measurement signals (7) into modified measurement signals (70) that depend on the real value of said real measurement signals (7) in said signal modifying computer (80);

sending said modified measurement signals (70) to said control system (2), wherein said one or more modified measurement signals (70) replaces one or more of said real measurement signals (7);

wherein said control system (2) acts upon said one or more modified measurement signals (70) and remaining unaffected real measurement signals (7);

for testing said control system (2) on errors represented by said modified measurement signal (70) imagined to occur in one or more sensors (8).

10. The method according to claim 9, said control system sending control signals (13) to said actuators (16, 17, 18) like propellers (16), thrusters (17), and rudders (18).

11. The method according to claim 9, said signal modifying computer (80) modifying said real measurement signals (7) in a relatively short time into modified measurement signals 1(70), so as for said control system (2) experiencing no significant delay of said modified measurement signals (70) as compared to the corresponding reception time said control system (2) would have received said real measurement signals (7).

12. The method of claim 9, said signal modifying computer (80) modifying one or more of said real measurement signals (7) into one or more modified measurement signals (70) that depend on the real value of said one or more real measurement signals (7), said modified measurement signals (70) being functions of said one or more real values of said measurement signals (7), said functions comprising adding constant or varying values to said real measurement signals (7), multiplying said real measurement signals (7) by constant or varying values, or using linear function depending on said real measurement signal to modify said real measurement signals (7).

13. The method according to claim 9, connecting one or more of said sensors (8) to said control system using one or more of sensor signal lines (12), and connecting said sensor simulator (80) on said sensor signal line (12) for receiving said one or more real sensor signals (8), and modifying said one or more real sensor signals in said sensor simulator (80) into said one or more modified sensor signals (70), and sending said one or more modified sensor signals (70) along said sensor signal lines (12) from said sensor simulator (80) to said control system (2).

14. The method according to claim 9, using one or more serial lines for said sensor signal lines (12), e.g. RS232, RS422.

15. The method according to claim 9, using one or more computer network bus lines like a redundant or non-redundant Ethernet network on UDP protocol, a Fieldbus or CAN-bus, or a radio signal transmission system.

16. The method according to claim 9, using one or more Ethernet communication lines, a fieldbus or CAN-bus, or a local radio communication system.