Abstract:
An automatic stabilization unit for watercraft such as boats, yachts and the like. In order to ensure stabilization of the watercraft with a high level of movement comfort at the same time over the entire speed range and in all water conditions, an electronic regulator is provided which stabilizes the water attitude of the watercraft during movement, while moving straight ahead and turning, as a function of the movement-situation-dependent rotation rates and longitudinal accelerations and/or lateral accelerations and/or vertical accelerations, using the actuating elements which are normally available in the watercraft, thus preventing or reducing to a minimum any stress on, damage to or danger to the boat, its occupants and the surrounding are thereof.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national phase application of PCT International Application No. PCT/EP2008/052795, filed Mar. 7, 2008, which claims priority to German Patent Application No. DE 10 2007 011 942.0, filed Mar. 9, 2007 and German Patent Application No. DE 10 2008 013 212.8, filed Mar. 7, 2008, the contents of such applications being incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an automatic stabilization unit for watercraft such as boats, yachts and the like. 
     2. Description of the Related Art 
     DE 38 03 942 C3 discloses an apparatus for influencing the water attitude of a boat which responds even at small trim or heel angles and in which the trim and the heel are controlled independently. In this case, when the watercraft is at an angle, the control device is intended to be activated directly in that a moving contact transmitter body applies control contacts as a result of the inclination of the watercraft. Control signals for application to the drives of trimming flaps are produced by means of the contact transmitter body, as a function of the central control switch. In the case of heel, the watercraft is automatically realigned irrespective of how the wind is blowing or how many people are sitting on one side. The control signals act on the propulsion motors of the starboard flaps and of the port flaps in the sense of opposing flap movements. In this case, the alignment is in each case relative to a single inclination plane. In order to trim the boat with reference to two mutually perpendicular inclination axes of a reference plane, the invention provides for inclined attitude compensation to be carried out by means of only that trimming flap which is diagonally opposite the deep point of the boat. The control switch which is used as a nominal value transmitter can in this case be aligned horizontally on two mutually perpendicular axes. 
     One known automatic trimming system for propulsion and flaps permanently compensates for the inclined attitude in the event of course changes, a side wind or movement of people on the watercraft, and automatically corrects the water attitude (automatic trimming system for propulsion and flaps, ACS, Mente Marine, P.O. Box 472, FIN-65101 Vaasa, Finland). Sensors are provided for this purpose, which identify the speed, the roll movements, the yaw and the pitch movement. A program corrects the water attitude of the boat while it is gliding, and ceases only when the boat changes to the displacement phase. Undershooting of the gliding speed is identified by means of the engine rotation speed, as determined by the sensor. In this case, the system is matched to the sea state. A different sea state is likewise identified by the system. In this case, when the water is smooth, the trimming system corrects more quickly than when the sea is rough. If the trimming system identifies turning by means of the yaw rate signal, then more extensive control action is actively prevented. Only when the boat is once again traveling straight ahead in a stable form is the trimming system switched on again. 
     The control signals emitted by the controllers for the trimming systems are used to control actuating elements, which are known per se, for the watercraft.  FIG. 1  illustrates a longitudinal trimming device  15  which allows power trimming of the watercraft by means of outboard motors and a Z drive. For this purpose, the longitudinal propulsion unit  23  of the watercraft is pivoted about the bearing point  9  in the direction of the arrow  8 . In addition, trimming flaps  16 ,  17  can be operated synchronously. 
     One known lateral trimming device may have the trimming flaps  16 ,  17  which are illustrated schematically in  FIG. 2 , can be operated electrically and/or hydraulically, and are operated asynchronously. 
     Furthermore, longitudinal propulsion devices  23 , for example at least one propulsion motor, usually in the form of an outboard motor, Z drive, shaft drive, are provided (EP1051326B1). A lateral propulsion device, which is not illustrated in any more detail, may have a bow jet steering device and/or a stern jet steering device. 
     The invention is based on the object of improving an automatic stabilization unit for watercraft such as boats, yachts and the like, such that the watercraft can be stabilized in all movement situations. 
     The known stabilization unit described initially, “Attitude Correction Systems—ACS A+” from Mente-Marine, has two functional blocks, by means of which automated longitudinal-trim control and heel compensation can be carried out, in each case when moving straight ahead. 
     SUMMARY OF THE INVENTION 
     The invention avoids the restrictions of the known stabilization unit to control when moving straight ahead and comprises the provision of an electronic regulator which stabilizes the water attitude of the watercraft during movement, while moving straight ahead and turning, as a function of the movement-situation-dependent rotation rates and longitudinal accelerations and/or lateral accelerations and/or vertical accelerations, using the actuating elements which are normally available in the watercraft, so as to prevent or reduce to a minimum stress, damage or danger to the watercraft, its occupants and its surrounding area. 
     One substantial factor in this case is that an automatic stabilization unit for watercraft, such as boats, yachts, ships, has an electronic regulator for movement stabilization, to which the measured or calculated movement-situation-dependent rotation rates and accelerations (longitudinal, lateral, vertical) are made available as actual variables, and the regulator stabilizes the water attitude of a powered watercraft at all times while moving straight ahead and turning, as a function of calculated nominal variables. 
     Longitudinal and lateral trimming devices and/or longitudinal and lateral propulsion units are expediently provided as actuating elements. 
     The electronic regulator advantageously has a control unit, by means of which freely variable application-specific movement programs can be set by the operator. In this case, the control unit can advantageously be used to set at least the prior-configured movement programs ECO, HARBOR, TROLL, WAVE, CRUISING, SKI, for example with ECO supporting economic movement, and HARBOR supporting HARBOR entrance. 
     Furthermore, the electronic regulator receives further input signals which assist the helmsman in his responsibility for predictive operation and collision prevention. The further input signals to the regulator are produced by systems in or on the watercraft, whose output signals are made available for channel identification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One exemplary embodiment will be described in more detail in the following text, and is illustrated in the drawing, in which: 
         FIG. 1  shows a schematic illustration of a longitudinal trimming device, in particular of power trimming by means of outboard motors and a Z drive, 
         FIG. 2  shows a schematic illustration of a lateral trimming device, in particular trimming flaps which can be operated electrically and/or hydraulically, 
         FIG. 3  shows a schematic illustration of a vehicle-fixed coordinate system of a watercraft with the associated angles, 
         FIG. 4  shows a schematic illustration of the roll angle in the vehicle-fixed coordinate system, 
         FIG. 5  shows a schematic illustration of the associated spatially fixed coordinate system in  FIG. 4 , 
         FIG. 6  shows an illustration of the relationship between the lateral dynamics and the roll angle, 
         FIG. 7  shows an illustration of the relationship between the roll angle and the accelerations, 
         FIG. 8  shows an illustration of the relationship between the longitudinal dynamics and the pitch angle, 
         FIG. 9  shows an illustration of the relationship between the pitch angle and the accelerations, 
         FIG. 10  shows a block diagram of the regulator for watercraft closed-loop control, 
         FIG. 11  shows an illustration of the angles on the horizontal plane. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1. General Definition of the Coordinate Systems of a Watercraft 
     If one considers a watercraft, for example a yacht or a boat, which is stationary, then three axes can be defined in a local orthogonal system: 
     Origin: the point at which the buoyancy force acts
     x axis: the longitudinal axis   y axis: the lateral axis   z axis: the vertical, corresponding to the direction of the buoyancy force.   

     If these three axes are transferred to the watercraft illustrated in  FIG. 3 , the following two coordinate systems can be considered: 
     Spatially fixed coordinate system x 0 -y 0 -z 0  with the origin at the vehicle center of gravity or zero point, with the z 0  axis pointing vertically upwards, the x 0  axis pointing forwards in the direction of travel, and the y 0  axis lying on the horizontal plane and running at right angles to the x 0  axis; this points to the left in the direction of travel. 
     Vehicle-fixed coordinate system x-y-z with the origin at the vehicle center of gravity, with the z axis running at right angles to the vehicle floor plane upwards, with the x axis being parallel to the vehicle floor plane and pointing forwards in the direction of travel, and with the y axis being parallel to the vehicle floor plane and pointing to the left in the direction of travel. 
     The vehicle-fixed coordinate system x-y-z can be created by two rotations, which are carried out successively, with respect to the spatially fixed coordinate system x 0 -y 0 -z 0 . Initially, the two coordinate systems are located one above the other ( FIG. 3 ). The vehicle-fixed coordinate system x-y-z is then rotated about the y 0  axis in the positive direction (direction of the arrow  11 ) through the angle φ. The x axis is therefore at the same angle φ to the x 0  axis. The angle φ is referred to as the pitch angle  13  of the watercraft  10 . The vehicle-fixed coordinate system x-y-z is then rotated about the x axis (direction of the arrow  12 ) through an angle κ. The angle κ illustrated in  FIG. 4  is referred to as the roll angle  14 . The spatially fixed coordinate system, indicated only schematically by dashed lines in  FIG. 4 , is illustrated separately in  FIG. 5 . 
     2. Movements of the Watercraft 
     When forces which are not vertical act on a watercraft, such as a ship or a boat, then the watercraft is moved; the floating watercraft  10  is a freely moving body with 6 degrees of freedom, and it can therefore carry out six different movements individually or combined: 
     Three translational:
         in the direction of the x axis: (forwards, backwards)   in the direction of the y axis: (sideways)   in the direction of the z axis: (diving)       

     and three rotational:
         rotation about the x axis: (heeling, rolling)   rotation about the y axis: (trimming, pitching)   rotation about the z axis: (rotation, yawing)       

     One simple example is forwards movement: when the longitudinal propulsion unit  23  is producing the force M in the negative x direction, then this results in forward movement. 
     3. Sensors and Measured Values 
     As  FIGS. 6 to 9  and  11  show, three acceleration sensors  18 , which are associated with the vehicle-fixed coordinate system x-y-z, are connected to the electronic regulator  20 , which will be described in more detail later. The sensors  18  measure the corresponding three acceleration components α xM , α yM  and α zM . Three angular velocity sensors  18  are likewise connected to the electronic regulator  20 , and are permanently associated with the vehicle-fixed coordinate system x-y-z. The sensors  18  measure the three angular velocities, as illustrated in  FIG. 3 , about the x, y and z axes. These are the roll rate {dot over (κ)}, pitch rate {dot over (φ)} and the yaw rate {dot over (ψ)}. 
     The invention also covers embodiments in which the accelerations and/or rates and velocities determined by the sensors  18  are also calculated or estimated from other signals, using models. 
     3.1 Roll Angle of the Watercraft (Roll Angle, Heel Angle) 
     The roll angle κ cannot be measured directly. The acceleration components in the y-z plane are observed in order to derive the roll angle κ. When turning, there are two acceleration components on the y-z plane α Q  and α v . In this case, α Q  is the lateral acceleration of the watercraft  10  in the Y0 direction, and α v  is the vertical acceleration in the Z0 direction. α Q  is approximately identical to the centripetal acceleration.
 
α Q   =V{dot over (α)}=V{dot over (ψ)}−V{dot over (β)}≈V{dot over (ψ)}   (20)
 
     where V=the velocity in the spatially fixed coordinate system, {dot over (α)}=vehicle course angle velocity, {dot over (ψ)}=yaw rate and {dot over (β)}=drift angular velocity. The angles on the horizontal plane, for example {dot over (ψ)} or {dot over (β)} or {dot over (α)}, are illustrated in more detail in  FIG. 11 . 
       FIG. 6  shows the relationship between the lateral dynamics and the roll angle of the watercraft. 
     The centrifugal force F F , which corresponds to the lateral acceleration, attempts to move the watercraft to the outside of the turn. An equilibrium in the lateral direction can be achieved only by a lateral force F Q  acting on the watercraft from water and of the same magnitude:
 
F Q =F F =mα Q ≈mV{dot over (ψ)}  (21)
 
     The watercraft is in equilibrium in the Z0 direction when the buoyancy force F A  has the same magnitude as the force of gravity F G =gm on the boat. In this case, g is the acceleration due to the earth&#39;s gravity, m is the mass. The buoyancy force F A  could produce a virtual vertical acceleration α v , if the force of gravity were not present. 
     If the watercraft  10  had no roll angle (κ=0), then the acceleration α yM  measured by the sensors  18  would be identical to the centripetal acceleration α Q  produced by the lateral force F Q , and the acceleration α zM  would be identical to the vertical acceleration α v  produced by the buoyancy force F A . If the watercraft  10  has a roll angle (κ≠0), then this results in the following relationship, as illustrated in  FIG. 7 , between the measured accelerations and the lateral acceleration α Q , as well as the virtual vertical acceleration α v :
 
α yM =(α Q  cos κ+α v  sin κ)
 
α zM =(α Q  sin κ+α v  cos κ)  (22)
 
     If the vertical movement of the watercraft  10  were to be ignored, then α v =g. Then: 
     
       
         
           
             
               
                 
                   
                     
                       
                         
                           κ 
                           = 
                             
                           ⁢ 
                           
                             γ 
                             - 
                             ϑ 
                           
                         
                       
                     
                     
                       
                         
                           = 
                             
                           ⁢ 
                           
                             
                               arc 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               sin 
                               ⁢ 
                               
                                 
                                   α 
                                   yM 
                                 
                                 
                                   
                                     
                                       g 
                                       2 
                                     
                                     + 
                                     
                                       α 
                                       Q 
                                       2 
                                     
                                   
                                 
                               
                               ⁢ 
                               arc 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               sin 
                               ⁢ 
                               
                                 
                                   α 
                                   Q 
                                 
                                 
                                   
                                     
                                       g 
                                       2 
                                     
                                     + 
                                     
                                       α 
                                       Q 
                                       2 
                                     
                                   
                                 
                               
                             
                             ≈ 
                             
                               
                                 
                                   α 
                                   yM 
                                 
                                 - 
                                 
                                   α 
                                   Q 
                                 
                               
                               
                                 
                                   
                                     g 
                                     2 
                                   
                                   + 
                                   
                                     α 
                                     Q 
                                     2 
                                   
                                 
                               
                             
                           
                         
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     
                       α 
                       Q 
                     
                     = 
                     
                       V 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         ψ 
                         . 
                       
                     
                   
                 
               
               
                 
                   ( 
                   23 
                   ) 
                 
               
             
           
         
       
     
     If the vertical movement of the boat is considered in detail, then: 
     
       
         
           
             
               
                 
                   
                     α 
                     Q 
                   
                   = 
                   
                     ( 
                     
                       
                         
                           α 
                           
                             γ 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             M 
                           
                         
                         ⁢ 
                         cos 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         κ 
                       
                       - 
                       
                         
                           α 
                           zM 
                         
                         ⁢ 
                         sin 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         κ 
                       
                     
                     ) 
                   
                 
               
               
                 
                   ( 
                   24 
                   ) 
                 
               
             
             
               
                 
                   
                     
                       
                         κ 
                         = 
                         
                           γ 
                           - 
                           ϑ 
                         
                       
                     
                   
                   
                     
                       
                         = 
                         
                           
                             arc 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             sin 
                             ⁢ 
                             
                               
                                 α 
                                 yM 
                               
                               
                                 
                                   
                                     α 
                                     zM 
                                     2 
                                   
                                   + 
                                   
                                     α 
                                     yM 
                                     2 
                                   
                                 
                               
                             
                             ⁢ 
                             arc 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             sin 
                             ⁢ 
                             
                               
                                 α 
                                 Q 
                               
                               
                                 
                                   
                                     α 
                                     zM 
                                     2 
                                   
                                   + 
                                   
                                     α 
                                     yM 
                                     2 
                                   
                                 
                               
                             
                           
                           ≈ 
                           
                             
                               
                                 α 
                                 yM 
                               
                               - 
                               
                                 α 
                                 Q 
                               
                             
                             
                               
                                 
                                   α 
                                   zM 
                                   2 
                                 
                                 + 
                                 
                                   α 
                                   yM 
                                   2 
                                 
                               
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   25 
                   ) 
                 
               
             
           
         
       
     
     If the lateral acceleration is small: 
     
       
         
           
             
               
                 
                   
                     
                       
                          
                         
                           α 
                           Q 
                         
                          
                       
                       ⪡ 
                       g 
                     
                     , 
                     
                       
                         
                           
                             g 
                             2 
                           
                           + 
                           
                             α 
                             Q 
                             2 
                           
                         
                       
                       ≈ 
                       g 
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     κ 
                     ≈ 
                     
                       
                         
                           α 
                           yM 
                         
                         - 
                         
                           α 
                           Q 
                         
                       
                       g 
                     
                   
                 
               
               
                 
                   ( 
                   26 
                   ) 
                 
               
             
           
         
       
     
     3.2 Pitch Angle of the Watercraft(Pitch Angle, Trim Angle) 
     The pitch angle of the watercraft cannot be detected directly, in precisely the same way as the roll, angle. When traveling straight ahead, the external forces acting on the boat and the corresponding accelerations can be broken down and illustrated on the XZ plane. When moving forwards, there is a propulsion force or longitudinal force F L , which acts in the X0 direction on the watercraft and produces a longitudinal acceleration α L . In addition, a buoyancy force F A  acts on the boat, pointing in the Z0 direction and compensating in particular for the force of gravity on the watercraft. Without the force of gravity, the buoyancy force F A  would produce a virtual vertical acceleration α v . 
     If the watercraft had no pitch angle (φ=0), then the acceleration α xM  measured by the sensors  18  would be identical to the longitudinal acceleration α L  produced by the longitudinal force F L , and the acceleration α zM  would be identical to the vertical acceleration α V  produced by the buoyancy force F A . If the boat has a pitch angle (φ≠0), then this results in the following relationship, as illustrated in  FIG. 9 , between the measured accelerations and the actual longitudinal acceleration α L , as well as the virtual vertical acceleration α V :
 
α xM =(α L  cos φ−α V  sin φ)
 
α xM =(α L  sin φ−α V  cos φ)  (27)
 
     If the vertical movement of the watercraft were to be ignored, then α V =g. Then: 
     
       
         
           
             
               
                 
                   
                     φ 
                     = 
                     
                       
                         θ 
                         - 
                         ɛ 
                       
                       = 
                       
                         
                           arc 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           sin 
                           ⁢ 
                           
                             
                               α 
                               L 
                             
                             
                               
                                 
                                   g 
                                   2 
                                 
                                 + 
                                 
                                   α 
                                   L 
                                   2 
                                 
                               
                             
                           
                           ⁢ 
                           arc 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           sin 
                           ⁢ 
                           
                             
                               α 
                               
                                 x 
                                 M 
                               
                             
                             
                               
                                 
                                   g 
                                   2 
                                 
                                 + 
                                 
                                   α 
                                   L 
                                   2 
                                 
                               
                             
                           
                         
                         ≈ 
                         
                           
                             
                               α 
                               L 
                             
                             - 
                             
                               α 
                               xM 
                             
                           
                           
                             
                               
                                 g 
                                 2 
                               
                               + 
                               
                                 α 
                                 L 
                                 2 
                               
                             
                           
                         
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     
                       α 
                       L 
                     
                     = 
                     
                       V 
                       . 
                     
                   
                 
               
               
                 
                   ( 
                   28 
                   ) 
                 
               
             
           
         
       
     
     If the vertical movement of the watercraft is considered in detail, then: 
     
       
         
           
             
               
                 
                   
                     α 
                     L 
                   
                   = 
                   
                     ( 
                     
                       
                         
                           α 
                           xM 
                         
                         ⁢ 
                         cos 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         φ 
                       
                       + 
                       
                         
                           α 
                           zM 
                         
                         ⁢ 
                         sin 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         φ 
                       
                     
                     ) 
                   
                 
               
               
                 
                   ( 
                   29 
                   ) 
                 
               
             
             
               
                 
                   
                     
                       
                         φ 
                         = 
                         
                           θ 
                           - 
                           ɛ 
                         
                       
                     
                   
                   
                     
                       
                         = 
                         
                           
                             arc 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             sin 
                             ⁢ 
                             
                               
                                 α 
                                 L 
                               
                               
                                 
                                   
                                     α 
                                     xM 
                                     2 
                                   
                                   + 
                                   
                                     α 
                                     zM 
                                     2 
                                   
                                 
                               
                             
                             ⁢ 
                             arc 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             sin 
                             ⁢ 
                             
                               
                                 α 
                                 xM 
                               
                               
                                 
                                   
                                     α 
                                     xM 
                                     2 
                                   
                                   + 
                                   
                                     α 
                                     zM 
                                     2 
                                   
                                 
                               
                             
                           
                           ≈ 
                           
                             
                               
                                 α 
                                 L 
                               
                               - 
                               
                                 α 
                                 xM 
                               
                             
                             
                               
                                 
                                   α 
                                   xM 
                                   2 
                                 
                                 + 
                                 
                                   α 
                                   zM 
                                   2 
                                 
                               
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   30 
                   ) 
                 
               
             
           
         
       
     
     If the longitudinal acceleration is small: 
     
       
         
           
             
               
                 
                   
                     
                       
                          
                         
                           α 
                           L 
                         
                          
                       
                       ⪡ 
                       g 
                     
                     , 
                     
                       
                         
                           
                             g 
                             2 
                           
                           + 
                           
                             α 
                             L 
                             2 
                           
                         
                       
                       ≈ 
                       g 
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     φ 
                     ≈ 
                     
                       
                         
                           α 
                           L 
                         
                         - 
                         
                           α 
                           xM 
                         
                       
                       g 
                     
                   
                 
               
               
                 
                   ( 
                   31 
                   ) 
                 
               
             
           
         
       
     
     4. Circuit Diagram of the Closed-Loop Control of the Watercraft 
       FIG. 10  shows an electronic regulator  20  which is connected to the sensors  18  in the watercraft  10 . The sensors  18  may be the acceleration, rate and velocity sensors mentioned in Section 3, which are associated with the vehicle-fixed coordinate system x-y-z. The sensors  18  determine the three acceleration components α xM , α yM , α zM  and the three angular velocities about the x, y and z axes. These are the roll rate {dot over (κ)}, pitch rate {dot over (φ)} or yaw rate {dot over (ψ)}. These control variables are passed to the regulator  20  in order to determine the watercraft movements, specifically the roll angle and pitch angle. Furthermore, additional sensors  18  or models for water depth detection, such as echo sounding, or pitch sensors, GPS, and the like and sensors  18  for identification of the helmsman&#39;s demand, such as steering angle sensors, sensors for determination of rate, velocity and acceleration presets by the helmsman and the like can be provided. Furthermore, sensors or models may be provided which determine the water depth, the fuel flow rate, the engine rotation speed, the rotation velocity of a paddle wheel or the engine torque. The regulator  20  has a first evaluation unit  22  for identification of the helmsman&#39;s demand. This first evaluation unit  22  is connected to an input unit  24 , by means of which freely variable application-specific movement programs can be set by the helmsman or operator. Movement programs that may be set on the input unit  24  via a keyboard or a switch, and/or wirelessly via a remote control include HARBOR, a maneuvering aid in very confined spaces; TROLL, a reduction in the minimum possible speed, a closed-loop compensation control system for waves from astern during stopping maneuvers; ECO, movement with maximum fuel efficiency, which can also be selected in addition to other movement programs; CRUISING, a cruise control system for most economical cruising; SKI, a movement program with a flat stern wave in which the velocity can be stored; WAVE, a movement program with a high stern wave in which the velocity can be stored. The helmsman presets by means of the movement programs via the man-machine interface and/or the direct presets by the helmsman by operations on the control element, such as the steering wheel, gas pedal, and/or the signals of the sensors  18 , are evaluated in the evaluation unit  22  with regard to the movement situations, and the nominal variables, for example fuel flow, engine rotation speed and the like, are supplied to the comparison unit  38 . The signals from the sensors  18  are supplied from the second evaluation unit  26 , which is connected to the sensors  18 , to the comparison unit  38  as actual variables, or after actual value calculation in a model. The nominal/actual discrepancies are determined in a regulator  40  as manipulated variables III for the actuators of the watercraft  10 , and are made available to the arbitration block  34 , in which the final manipulated variables are determined. 
     The method of operation of the regulator  20  will be described in more detail in the following text with reference to the determination of manipulated variables I, II from the roll and pitch angles. 
     The nominal roll angle and the nominal pitch angle are determined in the first evaluation unit  22 . The actual variables, that is to say the actual roll angle and the actual pitch angle, are calculated from the sensor values using equation (25) and equation (39) in the second evaluation unit  26 , which is supplied with the measured values from the sensors  18  as input variables. The respective discrepancies Δκ and Δφ are determined via a respective comparison unit  27 ,  28  from the nominal and actual roll angles κ Nom , κ Act  and the nominal and actual pitch angles φ Nom , φ Act . The output signal Δκ is supplied to the roll angle regulator  30 , and the output signal Δφ is supplied to the pitch angle regulator  32 , as input variables. The roll angle regulator  30  uses the roll angle discrepancy Δκ to calculate the corresponding manipulated variables II, for example in order to control the position of the trimming flaps  16 ,  17  and the like. The pitch angle regulator  32  uses the pitch angle discrepancy Δφ to calculate its own manipulated variables I for controlling, for example, the position of the trimming flaps  16 ,  17  and/or the pitch angle of the power trim  15 , etc. The final manipulated variables for controlling the actuating elements of the actuators are calculated from the two groups of manipulated variables I, II in the arbitration block  34 , which is connected to the roll angle regulator  30  and to the pitch angle regulator  32 . The actuating elements, for example hydraulic cylinders or electric motors, set these arbitrated manipulated variables of the actuators  15 ,  16 ,  17 . This acts directly on the watercraft, and influences the vehicle movements. The vehicle movement variables and the helmsman&#39;s demands are detected by the sensors  18 , and are fed back. 
     The nominal values, i.e. the different demands of the helmsman, regulations, movement programs can advantageously be preset by the helmsman. It is also possible to change the preset nominal values for the closed-loop control, during operation. 
     For fault identification reasons, all the calculations of the automatic regulator  20  are carried out redundantly and simultaneously on two processor cores, and are compared with one another. If a discrepancy is found between the two calculations, no control action is taken. Furthermore, the acceleration and rotation rate signals can be subjected to a plausibility check (faulty sensor signals can be identified). 
     5. Functional Scope 
     The regulator  20  is preferably a modular design and contains function modules which can be combined independently of one another, or building on one another, as a function of the sensors  18  in the watercraft  10  and the programs for calculation of input and/or output variables, as well as the actuators. 
     By way of example, the regulator  20  may have the following function modules: 
     Basic Module  1   a : Watercraft, Only with Power Trim Controller  15 
         longitudinal trim control when moving straight ahead   thrust force maximization when moving straight ahead   shallow water propulsion protection control       

     Basic Module  1   b : Watercraft, Only with Trimming Flap Controllers  16 ,  17 
         heel compensation when moving straight ahead   lateral trim control (lateral-force-reduced) when turning   yaw compensation when creeping straight ahead       

     Extension Module  2 : Watercraft with Power Trim  15  and Trimming Flap Controllers  16 ,  17 
         longitudinal trim control when turning   thrust force maximization when turning   rough water compensation control   load compensation during towing maneuvers on one side   HARBOR (maneuvering aid in a very confined space)   TROLL (reduction in the minimum possible speed)       

     Extension Module  3 : Watercraft with Additional Engine Torque Controller
         stern wave compensation control during stopping maneuvers   ECO (all functions for maximum fuel efficiency)   CRUISING (cruise control for most economical cruising)   SKI (small stern wave/velocity storable)   WAVE (high stern wave/velocity storable)       

     5.1 Control Methods 
     5.1.1 Longitudinal Trim Control when Moving Straight Ahead or when Turning 
     The regulator  20  carries out automatic longitudinal trim control when moving straight ahead or when turning, which influences the pitch angle φ of the watercraft  10  such that the watercraft  10  moves in the direction of travel at an optimum pitch angle φ with respect to the water surface in accordance with hydrodynamic laws, in order to exploit the more economical gliding movement as quickly and permanently as possible. 
     The regulator  20  is supplied as input variables with the signals from the sensors and/or the models for the longitudinal and vertical acceleration α xM , α zM  as well as the yaw rate {dot over (ψ)} (yaw angular velocity) and the velocity V of the watercraft  10  for longitudinal trim control when moving straight ahead, and in addition with the signals for the lateral acceleration α yM  for longitudinal trim control when turning. The vessel is moving straight ahead when the movement situation identification  22  determines that the signals {dot over (ψ)} of the yaw rate sensor  18  are within a tolerance band, formed on the basis of limit values with different mathematical signs, about the zero value (zero crossing). Turning occurs when the movement situation identification  22  determines that the values are outside the tolerance band after comparison of the signals from the yaw rate sensor  18  with the limit values of the tolerance band. The mathematical signs of the signals in this case indicate whether the watercraft  10  is turning to port or to starboard. A yaw rate sensor measures the rotation about the Z axis ( FIGS. 3 ,  11 ). When straight-ahead movement is found, the helmsman demand evaluation  22  determines the nominal pitch angle φ Nom , this is compared in the comparison unit  27  with the calculated actual pitch angle φ, and the nominal/actual discrepancy is made available to the pitch angle regulator  32 . This uses the discrepancy to determine the manipulated variable I for control of the longitudinal trimming devices, such as the power trim  15 . 
     When the movement situation identification  22  identifies that the vessel is turning, the roll angle discrepancy κ is also determined in the comparison unit  28 , and the final manipulated variables for longitudinal stability are determined in the arbitration block  34  from the two manipulated variables I, II determined in the pitch and roll angle regulators  30 ,  32 . The longitudinal and lateral trimming devices, such as the power trim  15  and the trimming flaps  16 ,  17 , are set by means of the final manipulated variables. The setting process is carried out such that this results in the best-possible combination of the longitudinal and vertical accelerations, determined by means of acceleration sensors  18 , when moving straight ahead, and longitudinal, lateral and vertical accelerations when turning, as a function of the velocity v. The velocity can be determined by means of a velocity sensor, such as a rotation speed sensor, GPS and the like. 
     In order to shorten the reaction time of the regulator  20  and in order to reduce the number and amplitude of the control cycles for the actuating devices  15 ,  16 ,  17  to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals from which the pitch rate and the engine rotation speed when moving straight ahead, or the pitch rate and roll rate as well as the engine rotation speed, can be determined. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as the trimming flaps  16 ,  17  when moving straight ahead and an engine torque controller when turning. 
     The longitudinal trim control achieves the following advantages:
     Unsecured occupants and/or objects falling or going overboard. Less fuel consumption as a result of faster entry to the gliding phase. Restricted view during the starting phase. Restricted controllability in the transitional phase. Improved acceleration and higher velocity.   

     5.1.2 Heel Compensation when Moving Straight Ahead 
     The regulator  20  controls automatic heel compensation when moving straight ahead, influencing the roll angle κ of the watercraft  10  such that the watercraft  10  always moves parallel to the water surface, and follows the predetermined course in the longitudinal direction. 
     The regulator  20  is supplied with the signals from the sensors and/or the models for the longitudinal, lateral and vertical acceleration α xM , α yM , α zM  as well as the yaw rate {dot over (ψ)} (yaw angular velocity) and the movement velocity V of the watercraft  10  for longitudinal trim control when moving straight ahead. Movement straight ahead is identified, corresponding to the description in 5.1.1, on the basis of the output signals from the yaw rate sensor  18 . This movement occurs when the measured yaw rate {dot over (ψ)} is within a tolerance band about the zero crossing. If the watercraft  10  is in this case moving at a velocity V greater than creeping speed, in particular greater than 3 km/h, the helmsman demand evaluation  22  determines the nominal roll angle κ Nom , which is compared in the comparison unit  28  with the calculated actual roll angle κ, and the nominal/actual discrepancy is made available to the roll angle regulator  30 , which uses the discrepancy to determine the manipulated variable I for controlling the lateral trimming devices, such as the trimming flaps  16 ,  17 , and makes this manipulated variable I available to the arbitration block  34 , which uses the determined manipulated variable I and possibly further manipulated variables III to determine the final manipulated variables for lateral stability. The lateral stability is then set by means of the existing lateral trimming devices, such as trimming flaps  16 ,  17 , so as to minimize the lateral acceleration α yM  relative to the watercraft  10 . 
     In order to shorten the reaction time of the system and in order to reduce to a minimum the number and amplitude of the control cycles for the actuating devices (life), a supporting movement dynamics model (software) is possible, based on further input signals from which a roll rate and the engine rotation speed can be determined. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as a power trim  15 . 
     The heel compensation achieves the following advantages:
     Unsecured occupants of the watercraft falling or going overboard (for example by a tilting/pitching movement of the vehicle);   Loss of unsecured objects by falling overboard (for example during heeling);   Propulsion damage by detection of lost objects   Inadvertent own steering inclination necessitates permanent steering correction (for example loading on one side)   

     5.1.3 Lateral Trim Control (Lateral-Force-Reduced) when Turning 
     The regulator  20  carries out automatic lateral trim control, which influences the boat inclination when turning such that the occupant can turn without any lateral force. Turning without any lateral force means that the roll angle κ is set to be free of lateral force. 
     The regulator  20  is supplied with the signals from the sensors and/or the models for the longitudinal, lateral and vertical acceleration α xM , α yM , α zM  as well as the yaw rate {dot over (ψ)} (yaw angular velocity) and the movement velocity V of the watercraft  10  for lateral trim control when turning. Turning is identified, corresponding to the description in 5.1.1, on the basis of the output signals from the yaw rate sensor  18 . This situation occurs when the measured yaw rate {dot over (ψ)} is outside a tolerance band around the zero crossing. The helmsman demand evaluation  22  then determines the nominal roll angle κNom without any lateral force, which is compared in the comparison unit  28  with the calculated actual roll angle κ, and the nominal/actual discrepancy is made available to the roll angle regulator  30 , which uses the discrepancy to determine the manipulated variable I for controlling the lateral trimming devices, such as the trimming flaps  16 ,  17 , and makes this manipulated variable I available to the arbitration block  34 , which uses the determined manipulated variable I and possibly further manipulated variables III to determine the final manipulated variables for lateral stability. The lateral stability is then set by means of the existing lateral trimming devices, such as trimming flaps  16 ,  17 , so as to minimize the lateral acceleration α yM  relative to the watercraft  10 . 
     In order to shorten the reaction time of the system and in order to reduce to a minimum the number and amplitude of the control cycles for the actuating devices, a supporting movement dynamics model (software) is possible, based on further input signals, which represent the roll rate, velocity and engine rotation speed. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as power trim and engine torque controllers. 
     The lateral trim control achieves the following advantages:
     Scratching/tearing/leakages of upholstery/floors/side walls caused by moving, unsecured objects (for example anchor, bottles)   Loss of unsecured objects by falling overboard   Propulsion damage by detection of lost objects   Dirt to clothing/inventory items by liquids running out (for example fuel, cleaning agents, drinks)   Unsecured occupants of the watercraft falling/being injured/going overboard   Body injuries caused by moving unsecured objects (for example anchor, tool, water ski/wakeboard)   Sufficiently large number of supporting/holding apparatuses required   All occupants of the watercraft must pay attention at all times (for example no people/children sleeping)   

     5.1.4 Thrust Force Maximization when Moving Straight Ahead and when Turning 
     The regulator  20  carries out automatic thrust force monitoring when moving straight ahead and when turning, with combined control, which identifies so-called propeller running in air of the longitudinal propulsion unit  23  and influences the power flow of the propeller in the water during movement such that the best possible efficiency is ensured at all times at the longitudinal propulsion unit/water power transmission point, thus also avoiding damage to the watercraft  10  and propulsion unit  23  as a result of rotation speed fluctuations/peaks. 
     The regulator  20  is supplied with the signals from the sensors  18  or the models, which are not described in any more detail, which represent the yaw rate, the relative vehicle velocity with respect to the water surface (paddle wheel, ram pressure gauge) and the engine rotation speed. Moving straight ahead or turning is identified by evaluation of the yaw rate from the yaw rate sensor. The signals provided by the sensors  18  or models, for the relative vehicle velocity and the engine rotation speed, are used to monitor the slip behavior between the longitudinal propulsion unit  23  and the water surface when moving straight ahead. When turning, the lateral, longitudinal and vertical accelerations α xM , α yM , α zM , as measured by the sensors  18 , are also determined and, using equation (25), the actual roll variable {dot over (ψ)} Act  determined in the second evaluation unit  26 , or its discrepancy as determined in the comparison unit  38 , of the longitudinal propulsion unit  23  with respect to the water surface is used to monitor the slip behavior. The slip behavior determined in this way is used to set the power flow by means of the existing longitudinal trimming devices  15  when moving straight ahead, and the longitudinal and lateral trimming devices  15 ,  16 ,  17  so as to achieve the least possible slip, that is to say discrepancy between the relative vehicle velocity and the associated engine rotation speed. The engine rotation speed is proportional to the rotation speed of the propeller. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals which represent the longitudinal acceleration. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as an engine torque controller. 
     Thrust force maximization achieves the following advantages:
     Drive damage caused by rotation speed peaks of the engine   Risk of so-called “softening” of the outboard level by power flow fluctuations (for example resulting from frequent, sudden loads of the level when under load)   Pitching of the body of the watercraft in conjunction with the sea state   Propeller running in air (for example as a result of inadequate immersion depth/incorrect trimming angle)   

     5.1.5 Shallow Water Propulsion Protection Control 
     The regulator  20  carries out automatic water depth monitoring during displacement movement with combined propulsion protection control which is intended to identify and prevent the longitudinal propulsion unit  23  from grounding, with as predictive a response as possible. 
     The regulator  20  is supplied with the signals from sensors  18  or models, which represent the absolute and spatially fixed vehicle velocity V of the watercraft  10 . Depending on the vehicle velocity of the watercraft  10 , the movement situation identification  22  of the regulator  20  identifies the movement situation of displacement movement, which is a lower level of gliding movement. On the basis of the monitored water depth profile, which is determined by sensors  18  such as echo sounding or is calculated in a model, the vehicle velocity V and the known trimming position of the longitudinal propulsion unit  15  are implemented on the basis of a nominal/actual depth prediction and the existing longitudinal trimming device or devices  23 , the power trim  15 , are used to set the immersion depth of the longitudinal propulsion unit  23  so as to prevent grounding. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the engine rotation speeds. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as an engine torque controller. 
     The shallow water propulsion protection control achieves the following advantages:
     Drive damage caused by grounding is prevented.   Propeller running in air when the immersion depth is too shallow (for example too much fuel with the longitudinal propulsion unit trimmed up).   

     5.1.6 Rough Water Compensation Control 
     The regulator  20  carries out automatic compensation control for rough water movement (sea state), which influences the pitch angle φ and the roll angle κ of the watercraft  10  such that the watercraft  10  is stabilized in a best-possible attitude, on the basis of hydrodynamic laws, with respect to a water surface with waves, in order to continue movement as safely and comfortably as possible in the direction of movement. 
     The regulator  20  is supplied with the signals from the sensors  18  or the models for the longitudinal, lateral and vertical acceleration α xM , α yM , α zM , the yaw rate {dot over (φ)}, the spatially fixed vehicle velocity of the watercraft  10  and the engine rotation speed of the longitudinal propulsion unit  23 . The movement situation identification  22  of the regulator  20  determines the movement situation of rough water movement as a function of the vehicle velocity V and the engine rotation speed. For this purpose, an increased propulsion slip in conjunction with superimposed rotation rates as shown by the arrows  11 ,  12 ,  19  for the pitch, roll and yaw angles  13 ,  14 ,  21  is determined on the basis of the discrepancies between the spatially fixed vehicle velocity of the watercraft  10  and the velocity calculated from the engine rotation speeds. On the basis of the determined propulsion slip and the rotation rates, the longitudinal stability and lateral stability are ensured by dynamic opposing control processes (compensation) by means of the existing longitudinal and lateral trimming devices, that is to say the trimming flaps  16 ,  17  and the power trim  15 , so as to achieve the minimum possible effect on the longitudinal, lateral and vertical movements of the watercraft  10 , as a function of the velocity. This prevents pitching of the watercraft. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the longitudinal, lateral and vertical accelerations. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as an engine torque controller. 
     The rough water compensation control achieves the following advantages:
     Unsecured occupants of the watercraft/objects falling/going overboard.   Restricted view as a result of a poor incidence angle with respect to the wave   Restricted course maintenance capability owing to cross-waves.   

     5.1.7 Yaw Compensation when Creeping Straight Ahead 
     The regulator  20  carries out automatic yaw moment control when moving slowly straight ahead, which influences the rolling, which is typical of a gliding boat, when moving slowly, such that the watercraft follows the helmsman&#39;s demand without any further steering correction. For this purpose, the trimming flaps  16 ,  17  are operated alternately to the port and starboard, in order to assist the straight-ahead movement. 
     The regulator  20  is supplied with the signals from the sensors  18  or the model, which represent the velocity and the yaw angle rate (yaw rate) of the watercraft  10 . The regulator  20  determines the movement situation of moving slowly straight ahead as a function of the velocity and the yaw rate. When the watercraft  10  is carrying out alternating yaw movements, that is to say when the watercraft  10  is not moving straight ahead as a result of rotation about the Z axis, the lateral stability is produced again by means of the existing lateral trimming devices, such as the trimming flaps  16 ,  17 , by dynamic opposing control (compensation), so as to achieve the minimum possible yaw rate. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the roll rate and the engine rotation speed. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as the power trim. 
     The yaw compensation when moving slowly straight ahead achieves the following advantages:
     Avoidance of inadvertent self-steering inclination, which otherwise necessitates permanent steering correction (for example when moving slowly (channel), heeling).   

     5.1.8 Stern Wave Compensation Control During Stopping Maneuvers 
     The regulator  20  carries out automatic stern wave compensation control during stopping maneuvers, which compensates for the stopping process, which is critical in the case of gliding boats, from gliding movement in conjunction with the immersion of the hull and the stern wave striking from the rear, such that the wave does not roll over the watercraft  10  from the stern, nor is the watercraft  10  turned by the wave (knocked sideways). 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models, which represent the relative vehicle velocity with respect to the water surface and the longitudinal acceleration of the watercraft  10 , and the engine rotation speed of the longitudinal propulsion unit  23 . The movement situation identification  22  determines the stopping maneuver movement situation as a function of the vehicle velocity, the longitudinal acceleration and the engine rotation speed. A stern wave prediction (wavelength/amplitude) is produced on the basis of the previous gliding movement velocity, and a propulsion thrust is initiated automatically by means of the existing longitudinal propulsion unit  23 , the engine torque controller, when the stern wave strikes, such that the watercraft  10  carries out a stabilizing longitudinal movement during the passage of the stern wave, thus reducing the relative velocity between the watercraft and the wave arriving from astern. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the vertical acceleration, the pitch rate and the yaw rate. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as the power trim and the trimming flaps. 
     The stern wave compensation controller during stopping maneuvers achieves the following advantages:
     Water inadvertently flowing over (for example an impacting stern wave)   Risk of the watercraft capsizing and being knocked sideways/knocked over.   

     5.1.9 Load Compensation During (Single-Sided) Towing Maneuvers 
     The regulator  20  carries out automatic load compensation control during (single-sided) towing maneuvers which influence the “mismatch” of the towing vessel with respect to course maintenance, water attitude and fuel consumption, such that the watercraft  10  can be controlled safely at all times, and follows the predetermined course. 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models for the longitudinal, lateral and vertical acceleration α xM , α yM , α zM  and the yaw rate {dot over (ψ)} (yaw angular velocity), the engine rotation speed of the longitudinal propulsion unit  23  and the velocity of movement V of the watercraft  10  for load compensation during (single-sided) towing maneuvers. The propulsion slip is determined as a function of the relative vehicle velocity and the engine rotation speed, a low velocity of movement is determined by means of the vehicle velocity signal, and a mismatched water attitude is determined as a function of the lateral acceleration and the yaw rate. The movement situation identification  22  determines the towing operation movement situation on the basis of the propulsion slip, which indicates that the watercraft is being operated on high load, the low movement velocity and the mismatched water attitude. When this situation occurs, the movement stability is set by using the determined manipulated variables to control the existing longitudinal and lateral trimming devices, the power trim  15  and the trimming flaps  16 ,  17 , so as to achieve the best possible water attitude with respect to the yaw rate and the lateral acceleration with respect to the stability nominal values. For this purpose, the arbitration block  34  is supplied with the manipulated variables I, II, III determined in the regulators  30 ,  32 ,  40 . 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the roll rate and the fuel consumption. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as the engine torque controller. 
     The load compensation during (single-sided) towing maneuvers achieves the following advantages:
     Unsecured occupants falling/going overboard (for example as a result of a pitching movement of the watercraft)   Loss of unsecured objects by falling overboard (for example during heeling)   Inadvertent self-steering inclination (for example single-sided load)   

     6. Movement Programs 
     6.1 Movement Programs in Parallel Operation 
     The input unit  24  of the electronic regulator  20  is used to input freely variable application-specific movement programs. The movement programs can be preselected in addition to the closed-loop control processes described in Section 5, provided that they are used in the relevant watercraft  10 . This results in the movement programs being operated in parallel with the closed-loop control processes. This results merely in priority switching and superimposition control. 
     6.1.1 ECO Mode (All Functions for Maximum Fuel Efficiency) 
     The input ECO on the input unit  24  of the regulator  20  leads to automatic variable-speed control for fuel efficiency improvement, which influences the closed-loop control processes described in Section 5 such that the respective control actions are carried out taking account of the best-possible fuel utilization. 
     After manual selection of the ECO mode on the input unit  24  and the closed-loop control process preferably identified on the basis of the input criteria, according to the description in Section 5, the respective control actions for the actuating devices described in Section 5 and the longitudinal propulsion unit  15 , such as the engine torque controller, are set in the regulator  20  so as to achieve the best-possible fuel efficiency. 
     The ECO mode achieves the following advantages:
     Reduced fuel consumption by avoidance of frequent and extreme load changes (for example acceleration, cyclic maneuvers)   

     6.1.2 Cruising Mode(Cruise Control for Most Economical Cruising) 
     The regulator  20  carries out automatic cruise control during cruising, which influences the velocity and the water attitude of the watercraft  10  such that the watercraft is always operated as economically as possible, at the highest possible cruise speed at the same time. 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models, which represent the velocity and the yaw rate on the watercraft  10  and the engine rotation speed as well as the fuel consumption of the longitudinal propulsion unit  15 . After manual selection of the CRUISING mode on the input unit  24  and constant gliding movement having been identified on the basis of the supplied signals, the movement velocity of the watercraft  10  is set by means of the longitudinal propulsion unit, advantageously engine torque controller, in a predefined velocity tolerance band—until deactivation of the CRUISING mode—so as to achieve an optimum water attitude and velocity but with the best possible cruise comfort and fuel efficiency. The closed-loop control processes described in Section 5 still remain active, and their priority is simply reduced. 
     The CRUISING mode achieves the following advantages:
     Permanent correction of the velocity as a function of the instantaneous consumption value (for example as a result of waves, wind). It is not necessary to know the most economical movement state of a boat (for example occasional helmsman, unfamiliar boat) stress resulting from simultaneous operation of a number of parallel systems is avoided (for example echo sounding, trimming flaps, steering).   

     6.1.3 SKI Mode (Small Stern Wave/Velocity Storable) 
     The regulator  20  carries out automatic water ski/towing boat control with preselectable intended velocity, which takes account of the particular requirements when towing a water skier, after a rapid start, a flat stern wave and a constant velocity. 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models, which represent the velocity of the watercraft  10  and the engine rotation speed of the longitudinal propulsion unit  15 . After manual selection of the SKI mode on the input unit  24  and identification of the stored target velocity (manual, reference movement after mode activation), the movement characteristics, preferably the velocity and the engine rotation speed, of the watercraft  10  are influenced during every further water ski start/movement, by means of the longitudinal propulsion unit, preferably the engine torque controller, such that the watercraft can be operated at most at the target velocity. The target velocity can be corrected upwards/downwards during operation, in defined steps, on the input unit  24 . The closed-loop control processes described in Section 5 still remain active, and just have their priority reduced. 
     The SKI mode achieves the following advantages:
     Better protection of the boat helmsman during towing operation   Better concentration of the boat helmsman on the water skier   Reproducibility of the towing process   

     6.2 Movement Program in Individual Operation 
     The input unit  24  of the electronic regulator  20  is used to input freely variable application-specific movement programs. The movement programs can be entered only on their own, without the closed-loop control processes described in Section 5, provided that they are used in the relevant watercraft  10 . The closed-loop control processes described in Section 5 must be manually deactivated, or are automatically deactivated when one of the following movement programs is entered. 
     6.2.1 WAVE Mode (High Stern Wave/Velocity Storable) 
     The regulator  20  carries out automatic wakeboard/towing boat control, which influences the incidence angle φ of the watercraft  10  when moving straight ahead such that the watercraft moves at an angle which is (hydrodynamically) as bad as possible with respect to the water surface in the direction of movement, in order to displace as much water as possible, with the large stern wave associated with this (desirable for wakeboarding!). 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models, which represent the yaw rate, the longitudinal and lateral acceleration and the velocity of the watercraft  10 , and the engine rotation speed of the longitudinal propulsion unit  15 . After manual selection of the WAVE mode on the input unit  24 , the regulator  20  uses the yaw rate to determine the movement situation. Movement straight ahead and the target velocity stored in a memory (manual, reference movement after mode activation). On every further start/movement, the movement characteristics of the watercraft  10  are influenced by means of the longitudinal trimming unit, such as the power trim, as well as the longitudinal propulsion unit, such as the engine torque controller, such that the watercraft  10  creates the largest possible stern wave, with a defined propulsion slip and target velocity. The largest possible stern wave is in this case controlled as a function of the longitudinal and vertical acceleration, the propulsion slip as a function of the velocity, and the engine rotation speed and the target velocity as a function of the velocity of the watercraft  10 . This limits the maximum speed during towing and can be corrected upwards/downwards during operation in defined steps on the control element. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting driving dynamics model (software) is possible, based on further input signals, such as the pitch rate. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as the trimming flaps. 
     The WAVE mode achieves the following advantages:
     Reproducibility of the towing process   Avoidance of expensive special accessories   

     6.2.2 HARBOR Mode (Maneuvering Aid in a Very Confined Space) 
     The regulator  20  carries out automatic maneuvering auxiliary control when the space and weather conditions are poor, making use of the supporting steering and deceleration effect of the trimming and propulsion units in the watercraft  10 , so as to assist turning and docking maneuvers as well as possible. 
     The regulator  20  is supplied with the signals from the sensors  18  and/or the models, which represent the velocity, the yaw rate and the roll rate of the watercraft  10 , and the engine rotation speed of the longitudinal propulsion unit  15 . After manual selection of the HARBOR mode on the input unit  24  and identification of speed is less than 3 km/h, an own-steering behavior, which is very restricted at low local velocities and through the lack of dynamic flow on the rudder of the watercraft  10 , is assisted by means of the existing longitudinal and lateral trimming devices, such as power trim and trimming flaps, by deliberate operation (amplification) so as to achieve the best possible effect on longitudinal and lateral movements, corresponding to the helmsman&#39;s demand as determined in  22 . 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the longitudinal and lateral acceleration. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as an engine torque controller. 
     The HARBOR mode achieves the following advantages:
     Easier docking maneuvers in a harbor   No damage to the watercraft itself, or to another watercraft   Course maintenance capability at low speeds   

     6.2.3 TROLL Mode (Reduction in the Lowest-Possible Speed) 
     The regulator  20  carries out automatic trolling auxiliary control of the required speed when moving slowly (idling, connected), which makes use of the supporting braking effect of the trimming units provided in the watercraft  10 , so as to assist as well as possible the further reduction of the lowest possible speed that can be traveled at. 
     The regulator  20  supplied with the signals from the sensors  18  and/or the models, which represent the velocity of the watercraft  10  and the engine rotation speed of the longitudinal propulsion unit  15 . After manual selection of the TROLL mode on the input unit  24 , the creeping movement situation is identified in the regulator  20  on the basis of the evaluation of the velocity and the engine rotation speed. The regulator  20  brakes the watercraft  10  by operating the existing longitudinal trimming devices, such as the trimming flaps and the power trim (amplification). This operation results in an increase in the wetted hull area and, in consequence, in the movement velocity being braked as well as possible. Creeping movement is identified on the basis of the velocity and the engine rotation speed. 
     In order to shorten the reaction time of the system and in order to reduce the number and amplitude of the control cycles for the actuating devices to a minimum, a supporting movement dynamics model (software) is possible, based on further input signals, such as the yaw rate. 
     In order to maximize the efficiency of the movement-dynamic action, it is possible to include further actuating devices, such as an engine torque controller. 
     The TROLL mode achieves the following advantages:
     Maintenance of the velocity restriction in harbors   Support of towfishes   A saving of complex trolling hardware solutions   Avoidance of continuous engagement and disengagement processes