Autopilot autorelease systems and methods
Techniques are disclosed for systems and methods to provide accurate, low lag, and reliable autopilot autorelease in a hydraulic steering system for mobile structures. A hydraulic steering system includes a logic device configured to communicate with an autopilot pump controller, a control surface reference sensor, an orientation sensor, and/or a gyroscope. Control and sensor signals provided by the pump controller and/or the various sensors are used to selectively enable and/or disable an autopilot release signal. The autopilot release signal enables or disables the autopilot pump controller and/or an autopilot pump, or controls the autopilot pump controller to enable or disable the autopilot pump.
1. A method comprising:
receiving control surface angles and autopilot control surface demands corresponding to a control surface for a mobile structure that is actuated by a hydraulic steering system;
receiving an angular velocity of the mobile structure corresponding to a direction of motion for the mobile structure generated by the control surface; and
selectively disabling an autopilot of the mobile structure by selectively enabling the autopilot release signal based, at least in part, on the angular velocity and the control surface angles and/or the autopilot control surface demands.
2. A method comprising:
receiving control surface angles and autopilot control surface demands corresponding to a control surface for a mobile structure that is actuated by a hydraulic steering system;
initiating an autorelease observation cycle based, at least in part, on the control surface angles and the autopilot control surface demands; and
selectively disabling an autopilot of the mobile structure by selectively enabling the autopilot release signal during the autorelease observation cycle based, at least in part, on the control surface angles and/or the autopilot control surface demands corresponding to the initiated autorelease observation cycle.
3. The method of claim 1 , comprising:
initiating an autorelease observation cycle based, at least in part, on the control surface angles and the autopilot control surface demands; and
selectively enabling the autopilot release signal during the autorelease observation cycle based, at least in part, on the control surface angles and/or the autopilot control surface demands corresponding to the initiated autorelease observation cycle.
4. The method of claim 3 , wherein the autopilot control surface demands comprise pump control signals provided to an autopilot pump controller of the hydraulic steering system, and wherein the initiating the autorelease observation cycle comprises:
detecting an autopilot pump drive reversal or approximately zero autopilot pump drive for a predetermined minimum period of time, based on the pump control signals; and
initiating the autorelease observation cycle based, at least in part, on the detected autopilot pump drive reversal, the detected approximately zero autopilot pump drive for the predetermined minimum period of time, or upon detecting a prior-enabled autopilot release signal.
5. The method of claim 3 , wherein:
the control surface angles comprise control surface sensor signals from a control surface sensor of the hydraulic steering system and the autopilot control surface demands comprise pump sensor signals provided by an autopilot pump controller of the hydraulic steering system; and
the method further comprises:
determining an estimated autopilot driven control surface angle corresponding to the autorelease observation cycle based, at least in part, on the pump sensor signals;
determining an actual driven control surface angle corresponding to the autorelease observation cycle based, at least in part, on the control surface sensor signals; and
selectively enabling the autopilot release signal based, at least in part, on the estimated autopilot driven control surface angle and the actual driven control surface angle.
6. The method of claim 5 , wherein the pump sensor signals comprise an autopilot pump speed, and wherein the determining the estimated autopilot driven control surface angle corresponding to the autorelease observation cycle comprises:
integrating the autopilot pump speed substantially over the duration of the observation cycle to determine the estimated autopilot driven control surface angle.
7. The method of claim 5 , wherein the control surface sensor signals comprise actual control surface angles, and wherein the determining the actual driven control surface angle corresponding to the autorelease observation cycle comprises:
determining a difference between first actual control surface angle measured substantially at a beginning of the autorelease observation cycle and a second actual control surface angle measured after the beginning of the autorelease observation cycle and within the autorelease observation cycle to determine the actual driven control surface angle.
8. The method of claim 3 , wherein the selectively enabling the autopilot release signal during the autorelease observation cycle comprises:
determining an estimated manual helm input based, at least in part, on the control surface angles and/or the autopilot control surface demands corresponding to the initiated autorelease observation cycle;
determining the estimated manual helm input is greater than a predetermined minimum release threshold; and
enabling the autopilot release signal.
9. The method of claim 3 , wherein the autopilot control surface demands comprise an autopilot pump speed provided by an autopilot pump controller of the hydraulic steering system, and wherein the initiating the autorelease observation cycle comprises:
integrating the autopilot pump speed substantially over the duration of the observation cycle to determine an estimated autopilot driven control surface angle; and
initiating the autorelease observation cycle upon detecting the estimated autopilot driven control surface angle is greater than a predetermined maximum integration reliability threshold.
10. The method of claim 1 , wherein:
the mobile structure comprises a watercraft;
the control surface comprises a rudder and/or an actuated propulsion system for the mobile structure that is actuated by an autopilot pump; and
the autopilot release signal is configured to control a logic device and/or an autopilot pump controller to discontinue providing pump control signals and/or power to the autopilot pump.
11. A system comprising:
a logic device configured to receive one or more sensor and/or control signals and provide an autopilot release signal for a hydraulic steering system coupled to a mobile structure, wherein the logic device is configured to:
receive control surface angles and autopilot control surface demands corresponding to a control surface for the mobile structure that is actuated by the hydraulic steering system;
receive an angular velocity of the mobile structure corresponding to a direction of motion for the mobile structure generated by the control surface: and
selectively disable an autopilot of the mobile structure by selectively enabling the autopilot release signal based, at least in part, on the angular velocity and the control surface angles and/or the autopilot control surface demands.
12. The system of claim 11 , wherein the logic device is configured to:
initiate an autorelease observation cycle based, at least in part, on the control surface angles and the autopilot control surface demands; and
selectively enable the autopilot release signal during the autorelease observation cycle based, at least in part, on the control surface angles and/or the autopilot control surface demands corresponding to the initiated autorelease observation cycle.
13. The system of claim 12 , wherein the autopilot control surface demands comprise pump control signals provided to an autopilot pump controller of the hydraulic steering system, and wherein the initiating the autorelease observation cycle comprises:
detecting an autopilot pump drive reversal or approximately zero autopilot pump drive for a predetermined minimum period of time, based on the pump control signals; and
initiating the autorelease observation cycle based, at least in part, on the detected autopilot pump drive reversal, the detected approximately zero autopilot pump drive for the predetermined minimum period of time, or upon detecting a prior-enabled autopilot release signal.
14. The system of claim 12 , wherein:
the control surface angles comprise control surface sensor signals from a control surface sensor of the hydraulic steering system and the autopilot control surface demands comprise pump sensor signals provided by an autopilot pump controller of the hydraulic steering system; and
the logic device is configured to:
determine an estimated autopilot driven control surface angle corresponding to the autorelease observation cycle based, at least in part, on the pump sensor signals;
determine an actual driven control surface angle corresponding to the autorelease observation cycle based, at least in part, on the control surface sensor signals; and
selectively enable the autopilot release signal based, at least in part, on the estimated autopilot driven control surface angle and the actual driven control surface angle.
15. The system of claim 14 , wherein the pump sensor signals comprise an autopilot pump speed, and wherein the determining the estimated autopilot driven control surface angle corresponding to the autorelease observation cycle comprises:
integrating the autopilot pump speed substantially over the duration of the observation cycle to determine the estimated autopilot driven control surface angle.
16. The system of claim 14 , wherein the control surface sensor signals comprise actual control surface angles, and wherein the determining the actual driven control surface angle corresponding to the autorelease observation cycle comprises:
determining a difference between first actual control surface angle measured substantially at a beginning of the autorelease observation cycle and a second actual control surface angle measured after the beginning of the autorelease observation cycle and within the autorelease observation cycle to determine the actual driven control surface angle.
17. The system of claim 12 , wherein the selectively enabling the autopilot release signal during the autorelease observation cycle comprises:
determining an estimated manual helm input based, at least in part, on the control surface angles and/or the autopilot control surface demands corresponding to the initiated autorelease observation cycle;
determining the estimated manual helm input is greater than a predetermined minimum release threshold; and
enabling the autopilot release signal.
18. The system of claim 12 , wherein the autopilot control surface demands comprise an autopilot pump speed provided by an autopilot pump controller of the hydraulic steering system, and wherein the initiating the autorelease observation cycle comprises:
integrating the autopilot pump speed substantially over the duration of the observation cycle to determine an estimated autopilot driven control surface angle; and
initiating the autorelease observation cycle upon detecting the estimated autopilot driven control surface angle is greater than a maximum integration reliability threshold.
19. The system of claim 11 , wherein:
the mobile structure comprises a watercraft;
the control surface comprises a rudder and/or an actuated propulsion system for the mobile structure that is actuated by an autopilot pump; and
the autopilot release signal is configured to control the logic device and/or an autopilot pump controller to discontinue providing pump control signals and/or power to the autopilot pump.