Abstract: A method for controlling a speed of a marine vessel includes accelerating the marine vessel in response to a launch command. The method then includes holding the vessel speed at a desired vessel speed with a controller using feedback control. The controller phases in a derivative term of the feedback control in response to determining that the following conditions are true: (a) the vessel speed is within a given range of the desired vessel speed; and (b) an acceleration rate of the marine vessel is less than a given value.

Abstract: A method and system for controlling a position of a marine vessel near an object are disclosed. A location sensor determines a location of the marine vessel, and a speed sensor determines a speed of the marine vessel. A control module is in signal communication with the location sensor and the speed sensor. A marine propulsion system is in signal communication with the control module. The control module determines if the marine vessel is within a predetermined range of the object based on the marine vessel's location. In response to determining that the marine vessel is within the predetermined range of the object, the control module controls the propulsion system to produce at least one of a braking linear thrust and a braking moment to counter current movement of the marine vessel.

Abstract: A method and system for controlling a position of a marine vessel near an object are disclosed. A location sensor determines a location of the marine vessel, and a speed sensor determines a speed of the marine vessel. A control module is in signal communication with the location sensor and the speed sensor. A marine propulsion system is in signal communication with the control module. The control module determines if the marine vessel is within a predetermined range of the object based on the marine vessel's location. In response to determining that the marine vessel is within the predetermined range of the object, the control module controls the propulsion system to produce at least one of a braking linear thrust and a braking moment to counter current movement of the marine vessel.

Abstract: A marine vessel is powered by a marine propulsion system and movable with respect to first, second, and third axes that are perpendicular to one another and define at least six degrees of freedom of potential vessel movement. A method for controlling a position of the marine vessel near a target location includes measuring a present location of the marine vessel, and based on the vessel's present location, determining if the marine vessel is within a predetermined range of the target location. The method includes determining marine vessel movements that are required to translate the marine vessel from the present location to the target location. In response to the marine vessel being within the predetermined range of the target location, the method includes automatically controlling the propulsion system to produce components of the required marine vessel movements one degree of freedom at a time during a given iteration of control.

Abstract: A method for steering a marine vessel powered by a marine engine and having a steerable marine device includes initiating a docking mode, and in response to initiation of the docking mode, reducing a steering ratio between input signals corresponding to steered positions of a steering wheel and output signals corresponding to desired steering angles of the marine device, such that the steering ratio is less than the steering ratio would otherwise be were the vessel in a non-docking mode. Input signals are accepted from the steering wheel, and output signals are generated based on the input signals and the reduced steering ratio. The output signals are sent to a steering actuator coupled to the marine device, which controls a position of the marine device to the desired steering angles.

Abstract: A method of operating a steer-by-wire steering system on a marine vessel includes receiving an initial component position of a steerable component and receiving an initial wheel position of a manually rotatable steering wheel with respect to a zero position. An initial normalized steering value is then calculated based on the initial component position, and the initial normalized steering value is correlated to the initial wheel position. The correlation between a subsequently received wheel position and a subsequently calculated normalized steering value is then adjusted by a recovery gain until the steering wheel reaches an aligned position with the steerable component.

Abstract: A trim control system includes a memory storing a plurality of trim profiles, each trim profile defining a unique relationship between a plurality of vessel speeds and respective propulsion device trim angles. The unique relationship is: (a) a calibrated relationship developed by determining optimal trim angles for a particular propulsion device powering a particular marine vessel at a number of tested vessel speeds and a number of different conditions; or (b) developed by modifying a nominal relationship between a number of vessel speeds and a number of corresponding trim angles. An input device allows a user to select one of the trim profiles from the memory so as to specify an aggressiveness of trim angle relative to vessel speed. A controller determines a setpoint trim angle corresponding to measured vessel speed according to the selected trim profile. The control system positions the propulsion device at the setpoint trim angle.

Abstract: A trim control system automatically controls trim angle of a marine propulsion device with respect to a vessel. A memory stores trim base profiles, each defining a unique relationship between vessel speed and trim angle. An input device allows selection of a base profile to specify an aggressiveness of trim angle versus vessel speed, and then optionally to further refine the aggressiveness. A controller then determines a setpoint trim angle based on a measured vessel speed. If the user has not chosen to refine the aggressiveness, the controller determines the setpoint trim angle from the selected base profile. However, if the user has chosen to refine the aggressiveness, the controller determines the setpoint trim angle from a trim sub-profile, which defines a variant of the relationship between vessel speed and trim angle defined by the selected base profile. The control system positions the propulsion device at the setpoint trim angle.

Abstract: A method for automatically controlling a trim position of a trimmable drive unit with respect to a transom of a marine vessel includes retrieving from a memory a stored level trim position of the drive unit, measuring an actual trim position of the drive unit, and determining with a controller whether an absolute difference between the level trim position and the actual trim position exceeds a given threshold. The method also includes determining whether at least one of a plurality of trim-to-level enable conditions indicative of an idle state of an engine powering the drive unit is true. In response to a determination that the absolute difference exceeds the given threshold and that at least one trim-to-level enable condition is true, the method includes sending a control signal with the controller to trim the drive unit to the level trim position. A system for carrying out the method is provided.

Abstract: A method for maintaining position and/or heading of a marine vessel in a body of water includes accepting a command to maintain the vessel at an initial selected position and/or heading, and utilizing position/heading feedback control to determine initial steering angles, gear positions, and engine speeds for the vessel's propulsion devices that cause the propulsion devices to produce thrust that counteracts a net external force and moment on the vessel and maintains the vessel at the initial selected position/heading. The method also includes propelling the vessel to a new selected position/heading, and accepting a command to maintain the vessel at the new selected position/heading. The method next includes utilizing information related to one of the position/heading feedback control and the propulsion devices' thrust to predict control parameters required to maintain the vessel at the new selected position/heading, and controlling the propulsion device according to the predicted control parameters.

Abstract: A method for controlling a position of an electronic throttle valve of an internal combustion engine is provided. The method includes determining a desired throttle valve position; determining a first feed forward signal based on a rate of change between a previous throttle valve position and the desired throttle valve position; and determining a second feed forward signal based on a comparison of the desired throttle valve position to a limp home position of the throttle valve, in which the throttle valve is biased open by a spring. A summation of the first and second feed forward signals is used to actuate the throttle valve. After the throttle valve has been actuated according to the first and second feed forward signals, the position of the throttle valve is controlled with a feedback controller to obtain the desired throttle valve position.

Abstract: A method for maintaining a marine vessel at a global position and/or heading includes receiving measurements related to vessel attitude and estimating water roughness conditions based on the measurements. A difference between the vessel's actual global position and the target global position and/or a difference between the vessel's actual heading and the target heading are determined. The method includes calculating a desired linear velocity based on the position difference and/or a desired rotational velocity based on the heading difference. The vessel's actual linear velocity and/or actual rotational velocity are filtered based on the roughness conditions. The method includes determining a difference between the desired linear velocity and the filtered actual linear velocity and/or a difference between the desired rotational velocity and the filtered actual rotational velocity.

Abstract: Systems and methods for reducing steering pressures of marine propulsion device steering actuators are disclosed. First and second sensors sense first and second conditions of first and second steering actuators. A third sensor senses an operating characteristic of the marine vessel. A controller is in signal communication with the first, second, and third sensors. In response to the marine vessel travelling generally straight ahead, the controller determines a target toe angle between the first and second marine propulsion devices based on the operating characteristic. The controller commands the first and second steering actuators to position the first and second marine propulsion devices at the target toe angle. The controller thereafter gradually adapts the target toe angle between the first and second marine propulsion devices until the controller determines that an absolute difference between the first condition and the second condition reaches a calibrated value.

Abstract: Systems and methods disclosed herein control position of a trimmable drive unit with respect to a marine vessel. A controller determines a target trim position as a function of vessel or engine speed. An actual trim position is measured and compared to the target trim position. The controller sends a control signal to a trim actuator to trim the drive unit toward the target trim position if the actual trim position is not equal to the target trim position and if at least one of the following is true: a defined dwell time has elapsed since a previous control signal was sent to the trim actuator to trim the drive unit; a given number of previous control signals has not been exceeded in an attempt to achieve the target trim position; and a difference between the target trim position and the actual trim position is outside of a given deadband.

Abstract: A drive-by-wire control system for steering a propulsion device on a marine vessel includes a steering wheel that is manually rotatable and a steering actuator that causes the propulsion device to steer based upon rotation of the steering wheel. The system further includes a resistance device that applies a resistance force against rotation of the steering wheel, and a controller that controls the resistance device to vary the resistance force based on at least one sensed condition of the system.

Abstract: A method for controlling a speed of a marine vessel includes accelerating the marine vessel in response to a launch command. The method then includes holding the vessel speed at a desired vessel speed with a controller using feedback control. The controller phases in a derivative term of the feedback control in response to determining that the following conditions are true: (a) the vessel speed is within a given range of the desired vessel speed; and (b) an acceleration rate of the marine vessel is less than a given value.

Abstract: A controller carries out a method for positioning multiple trimmable marine propulsion devices on a marine vessel transom. The method includes identifying two propulsion devices located one on either side of a transom centerline and defining these as outer propulsion devices. A third propulsion device coupled to the transom between the outer propulsion devices is defined as an inner propulsion device. A user input is received to trim the outer and inner propulsion devices in a single direction with respect to their current trim angles. In response to the user input, the controller outputs a control signal. In response to the control signal, the outer propulsion devices are trimmed in the single direction to a first trim angle and the inner propulsion device is trimmed in the single direction to a second, different trim angle. The controller may rate limit trimming of the outer propulsion devices to accomplish this.

Abstract: A method of predicting manifold air pressure in an internal combustion engine during idle comprising the steps of receiving an idle air control (IAC) duty cycle value from an idle air controller, receiving an atmospheric pressure, and predicting a manifold pressure in an engine control unit based on the IAC duty cycle value and the atmospheric pressure.

Abstract: A trim control system automatically controls trim angle of a marine propulsion device with respect to a vessel. A memory stores trim base profiles, each defining a unique relationship between vessel speed and trim angle. An input device allows selection of a base profile to specify an aggressiveness of trim angle versus vessel speed, and then optionally to further refine the aggressiveness. A controller then determines a setpoint trim angle based on a measured vessel speed. If the user has not chosen to refine the aggressiveness, the controller determines the setpoint trim angle from the selected base profile. However, if the user has chosen to refine the aggressiveness, the controller determines the setpoint trim angle from a trim sub-profile, which defines a variant of the relationship between vessel speed and trim angle defined by the selected base profile. The control system positions the propulsion device at the setpoint trim angle.

Abstract: A method for setting an engine speed of an internal combustion engine in a marine propulsion device of a marine propulsion system to an engine speed setpoint includes determining the engine speed setpoint based on an operator demand and predicting a position of a throttle valve that is needed to achieve the engine speed setpoint. The method also includes determining a feed forward signal that will move the throttle valve to the predicted position, and after moving the throttle valve to the predicted position, adjusting the engine speed with a feedback controller so as to obtain the engine speed setpoint. An operating state of the marine propulsion system is also determined. Depending on the operating state, the method may include determining limits on an authority of the feedback controller to adjust the engine speed and/or determining whether the operator demand should be modified prior to determining the engine speed setpoint.