Stopping function for marine vehicle propulsion system

Abstract

Different solutions to stop automatically a vessel, which includes at least a first cycloidal propeller unit and a second cycloidal propeller unit, are disclosed. During a stopping procedure motion control values of at least the first cycloidal propeller unit are adjusted to cause, while maintaining a movement direction of the vessel to be according to a latest steering command, the first cycloidal propeller unit to brake in a first mode or in a second mode. In the first mode the main wheel is rotating, and blades of the cycloidal propeller unit are rotated to change a thrust direction towards to a reverse thrust direction. In the second mode either the main wheel is kept in a first position and the blades are positioned individually towards a corresponding predetermined angle to the movement direction or the blades are kept in first positions and the main wheel is rotated.

1 . A method for stopping a vessel, which vessel comprises at least a first cycloidal propeller unit and a second cycloidal propeller unit, a cycloidal propeller unit including a rotatable main wheel equipped with two or more blades that are individually rotatable, the method comprising:
 starting, in response to receiving an input triggering an automatic stopping procedure, a stopping procedure including at least the following:   obtaining at least information indicating a speed of the vessel; and   adjusting, based on at least the speed indicated, motion control values of at least the first cycloidal propeller unit to cause, while maintaining a movement direction of the vessel to be according to a latest steering command, the first cycloidal propeller unit to brake in a first mode or in a second mode, wherein the first mode is a cycloidal propeller braking mode in which the main wheel is rotating and blades of the cycloidal propeller unit are rotated to change a thrust direction at the time the input is received towards to a reverse thrust direction, and the second mode is a rudder like braking mode in which either the main wheel is kept in a first position and the blades are positioned individually towards a corresponding predetermined angle to the movement direction or the blades are kept in first positions and the main wheel is rotated.   
     
     
         2 . The method of  claim 1 , wherein the stopping procedure further comprises at least:
 reducing, before adjusting, the speed indicated to a first speed by changing propulsion of at least one of the first and second cycloidal propeller units; and   starting the adjusting when the speed indicated is not exceeding the first speed.   
     
     
         3 . The method of  claim 1 , wherein the stopping procedure further comprises at least a normal stopping operation mode and an emergency stopping operation mode, the method further comprising:
 determining stopping operation mode based on the input;   obtaining a set of operational parameter values predefined for the stopping operation mode determined, wherein the operational parameter values for the normal stopping operation mode are predefined for optimizing between a maximum stopping effect and a maximum component lifetime, and the operational parameter values for the emergency stopping operation mode are predefined for a maximum stopping effect; and   performing the adjusting by applying the operational parameter values to determine the motion control values.   
     
     
         4 . The method of  claim 1 , wherein the stopping procedure further comprises at least:
 performing the adjusting gradually in a step-wise manner, the step-wise manner including at least, per a step:   obtaining, when the speed decreases to a maximum speed value of a step, a set of operational parameter values predefined for the step; and   performing the adjusting by applying the operational parameter values to determine the motion control values.   
     
     
         5 . The method of  claim 4 , the operational parameter values in the first mode comprise values for a rotational speed, a pitch function parameter, and a steering parameter and in the second mode values for blade pitch angles. 
     
     
         6 . The method of  claim 5 , further comprising in the first mode:
 selecting, based on the speed, a pitch function amongst pitch functions including at least trochoidal and epicycloid pitch functions for stopping;   inputting the set of operational parameter values obtained to the pitch function selected; and   rotating the blades according to motion control values output by the pitch function selected.   
     
     
         7 . The method of  claim 2 , further comprising in the first mode at least:
 rotating, when the adjustment is started, the blades to cause thrust direction of the cycloidal propeller unit to change to be substantially perpendicular to the thrust direction at the time the input was received; and   rotating, when the speed indicated is below a second speed, which is lower than the first speed, the blades to cause thrust direction of the cycloidal propeller unit to change to be the reverse thrust direction.   
     
     
         8 . The method of  claim 1 , wherein in the second mode a value of a predetermined angle to the movement direction is up to ±90 degrees, and two or more of the two or more blades may have the same value or different values. 
     
     
         9 . The method of  claim 1 , wherein the stopping procedure further comprises at least:
 adjusting the first and second cycloidal propeller units substantially symmetrically with respect to a longitudinal axis of the vessel using first motion control values;   receiving, after the input, a steering command changing the movement direction of the vessel;   determining second motion control values based at least on the speed and the steering command received;   adjusting, after the steering command, one of the first and second cycloidal propeller units using the first motion control values and the other one using the second motion control values.   
     
     
         10 . The method of  claim 9 , wherein
 the first and second cycloidal propeller units are both adjusted using first motion control values, they are both caused to brake either in the first mode or in the second mode; and   the first motion control values and the second motion control values are used in the adjusting, one of the first and second cycloidal propeller units is caused to brake in the first mode and the other one is caused to brake in the second mode.   
     
     
         11 . The method of  claim 1 , further comprising:
 receiving an input cancelling the automatic stopping procedure;   stopping the stopping procedure; and   entering a normal operation mode.   
     
     
         12 . An apparatus comprising:
 at least one processor; and   at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the apparatus at least to perform:   start, in response to receiving an input triggering an automatic stopping procedure for stopping a vessel, which vessel comprises at least a first cycloidal propeller unit and a second cycloidal propeller unit, a cycloidal propeller unit including a rotatable main wheel equipped with two or more blades that are individually rotatable, a stopping procedure comprising at least the following:   obtaining at least information indicating a speed of the vessel; and   adjusting, based on at least the speed indicated, motion control values of at least the first cycloidal propeller unit to cause, while maintaining a movement direction of the vessel to be according to a latest steering command, the first cycloidal propeller unit to brake in a first mode or in a second mode, wherein the first mode is a cycloidal propeller braking mode in which the main wheel is rotating and blades of the cycloidal propeller unit are rotated to change a thrust direction at the time the input is received towards to a reverse thrust direction, and the second mode is a rudder like braking mode in which either the main wheel is kept in a first position and the blades are positioned individually towards a corresponding predetermined angle to the movement direction or the blades are kept in first positions and the main wheel is rotated.   
     
     
         13 . The apparatus of  claim 12 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to perform during the stopping procedure following:
 reducing, before adjusting, the speed indicated to a first speed by changing propulsion of at least one of the first and second cycloidal propeller units;   starting the adjusting when the speed indicated is not exceeding the first speed.   performing the adjusting gradually in a step-wise manner, the step-wise manner comprising at least, per a step:   obtaining, when the speed decreases to a maximum speed value of a step, a set of operational parameter values predefined for the step; and   performing the adjusting by applying the operational parameter values to determine the motion control values.   
     
     
         14 . The apparatus of  claim 12 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
 determine stopping operation mode amongst at least a normal stopping operation mode and an emergency stopping operation mode based on the input;   obtain a set of operational parameter values predefined for the stopping operation mode determined, wherein the operational parameter values for the normal stopping operation mode are predefined for optimizing between a maximum stopping effect and a maximum component lifetime, and the operational parameter values for the emergency stopping operation mode are predefined for a maximum stopping effect; and   perform the adjusting by applying the operational parameter values to determine the motion control values.   
     
     
         15 . The apparatus of  claim 13 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to perform in the first mode:
 selecting, based on the speed, a pitch function amongst pitch functions comprising at least trochoidal and epicycloid pitch functions for stopping;   inputting the set of operational parameter values obtained to the pitch function selected; and   rotating the blades according to motion control values output by the pitch function selected,   wherein the operational parameter values in the first mode include values for a rotational speed, a pitch function parameter, and a steering parameter.   
     
     
         16 . The apparatus of  claim 13 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
 rotate, in the first mode, when the adjustment is started, the blades to cause thrust direction of the cycloidal propeller unit to change to be substantially perpendicular to the thrust direction at the time the input was received; and   rotate, in the first mode, when the speed indicated is below a second speed, which is lower than the first speed, the blades to cause thrust direction of the cycloidal propeller unit to change to be the reverse thrust direction.   
     
     
         17 . The apparatus of  claim 12 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
 adjust the first and second cycloidal propeller units substantially symmetrically with respect to a longitudinal axis of the vessel using first motion control values;   receive, after the input, a steering command changing the movement direction of the vessel;   determine second motion control values based at least on the speed and the steering command received;   adjust, after the steering command, one of the first and second cycloidal propeller units using the first motion control values and the other one using the second motion control values.   
     
     
         18 . The apparatus of  claim 17 , wherein the at least one memory and computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
 cause both the first and second cycloidal propeller units to brake either in the first mode or in the second mode when the first and second cycloidal propeller units are both adjusted using first motion control values; and   cause one of the first and second cycloidal propeller units to brake in the first mode and the other one is caused to brake in the second mode when the first motion control values and the second motion control values are used in the adjusting.   
     
     
         19 . A vessel comprising:
 at least a first cycloidal propeller unit and a second cycloidal propeller unit, a cycloidal propeller unit comprising a rotatable main wheel equipped with two or more blades that are individually rotatable;   a movement control arrangement including at least one apparatus configured to start, in response to receiving an input triggering an automatic stopping procedure, a stopping procedure including at least the following: obtaining at least information indicating a speed of the vessel; and adjusting, based on at least the speed indicated, motion control values of at least the first cycloidal propeller unit to cause, while maintaining a movement direction of the vessel to be according to a latest steering command, the first cycloidal propeller unit to brake in a first mode or in a second mode, wherein the first mode is a cycloidal propeller braking mode in which the main wheel is rotating and blades of the cycloidal propeller unit are rotated to change a thrust direction at the time the input is received towards to a reverse thrust direction, and the second mode is a rudder like braking mode in which either the main wheel is kept in a first position and the blades are positioned individually towards a corresponding predetermined angle to the movement direction or the blades are kept in first positions and the main wheel is rotated;   at least one first user interface element to change, in response to a user input to the first user interface element, status of the automatic stopping procedure, the user interface element being connected to the movement control arrangement; and   at least one second user interface element to steer the vessel.   
     
     
         20 . The vessel of  claim 19 , wherein the at least one first user interface element comprises a plurality of user interface elements for a plurality of stopping operation modes including at least a normal stopping operation mode and an emergency stopping operation mode.