EP1806278A1 - Boat propulsion control method - Google Patents

Abstract

The method involves determining thrust exerted on a water vehicle by a boat drive, and controlling and/or regulating the drive depending on the determined thrust. A speed of the water vehicle is determined by a satellite navigation system, and a power transmitted by the drive to the water vehicle is determined from the thrust force and the speed. An efficiency of the drive is determined from a ratio of the power transmitted to the water vehicle and the power received by the drive. An independent claim is also included for a drive system for a water vehicle with a boat drive.

Description

The invention relates to a method for characterizing a boat drive driving a watercraft. Furthermore, the invention relates to a drive system for a boat-powered vessel, in particular an outboard motor, and attachment means connected to the boat drive and which serve for securing the propulsion system to the vessel, wherein the boat propulsion is movably arranged relative to the attachment means.

The power supply of boats with gasoline engines via a located on board the boat fuel tank. The maximum achievable range with the boat depends on the size of the fuel tank and the driving style. For a given speed the largest possible range is achieved when the boat drive is always operated with optimum efficiency.

The electrical energy necessary for the operation of electric motors is supplied by batteries, usually rechargeable batteries, i. Batteries, provided. Accordingly, the range of an electrically powered boat is limited by the capacity of the batteries. However, these are comparatively large and heavy, so that only a limited number of batteries can be accommodated on a boat.

Due to the limited amount of energy carried on board a boat, there is a need to operate a boat drive with the highest possible efficiency in order to optimally utilize the limited capacity of the fuel tank or of the batteries.

This assumes that the parameters characterizing a boat drive are known as well as possible. So far, the efficiency of boat drives is defined by the power they absorb.

Object of the present invention is to develop a method for characterizing a boat propulsion, which allows more accurate statements about the performance and the applications of a boat propulsion.

Furthermore, a method is to be shown, which allows to operate a boat drive shown with the highest possible efficiency. The method should enable improved control and / or regulation of a boat drive, in particular via an efficiency-optimized control.

Next, a propulsion system for a watercraft to be developed, which allows such optimized control and / or regulation.

This object is achieved on the method side by a method for characterizing a boat drive driving a watercraft, wherein the thrust exerted by the boat drive on the watercraft is determined.

The invention relates to a method for characterizing a propulsion system for a watercraft. The term "watercraft" is understood in the following to mean any type of vehicle moving on or in the water. In particular, should be included by this name boats or ships with outboard drive, either with electric motor or with gasoline engine. The drive can be done for example via propeller or impeller.

In the following description, the term "thrust" should be understood not only in the narrow sense as a thrust, but also capture any size proportional to the thrust. For example, the pressure exerted by the thrust of the boat drive on a certain area pressure can be determined. This then provides a qualitative statement about the thrust and with knowledge of the area can be calculated in a simple manner, the thrust force quantitatively.

The invention is based on the finding that, for optimum regulation and control of a boat drive, it is not only permitted to lift off the power absorbed by the boat drive, but that, in particular, the power transmitted to the watercraft is to be used. Only the determination according to the invention of the water actually applied to the vessel Schubs allows a precise characterization of the boat drive. This makes it possible to design a boat drive according to the purpose and to optimize the efficiency.

Preferably, the speed of the watercraft or boat is additionally determined. The speed measurement is preferably carried out via a satellite navigation system (GPS) or a log, for example via a patent log, a dynamic pressure log or an impeller attached to the bottom of the boat.

By multiplying the thrust exerted by the boat propulsion on the vessel with the speed of the vessel, the power absorbed by the vessel and used for propulsion is directly calculated.

wobei

• F = auf das Wasserfahrzeug ausgeübte Schubkraft
• v = Geschwindigkeit des Wasserfahrzeugs
• U = elektrische Spannung
• l = Stromstärke

The efficiency of the boat drive results from the ratio of the power used for the advancement of the vessel to the amount of energy absorbed by the boat drive per unit of time, that is, the power consumed. If the boat drive is designed as an electric motor, the power consumed by the electric motor is preferably calculated as the product of voltage and current. The efficiency of the electric motor is then determined to $$\mathrm{\eta }\mathrm{=}\left(\mathrm{F}\mathrm{•}\mathrm{v}\right)\mathrm{/}\left(\mathrm{U}\mathrm{•}\mathrm{I}\right)$$

in which

• F = thrust applied to the vessel
• v = speed of the vessel
• U = electrical voltage
• l = current

wobei

• F = auf das Wasserfahrzeug ausgeübte Schubkraft
• v = Geschwindigkeit des Wasserfahrzeugs
• V/t = Kraftstoffverbrauch pro Zeiteinheit
• E/V = Energieinhalt pro Volumen Kraftstoff

The inventive determination of the efficiency takes place in gasoline engines according to the formula $$\mathrm{\eta }\mathrm{=}\left(\mathrm{F}\mathrm{•}\mathrm{v}\right)\mathrm{/}\left(\mathrm{V}\mathrm{/}\mathrm{t}\mathrm{•}\mathrm{e}\mathrm{/}\mathrm{V}\right)$$

in which

• F = thrust applied to the vessel
• v = speed of the vessel
• V / t = fuel consumption per unit time
• E / V = energy content per volume of fuel

Thus, the fuel flow to the engine per unit time is measured and multiplied by the specific energy content of the fuel. From this, the power consumed by the gasoline engine is calculated. The power converted to the advancement of the vessel is determined from the thrust force and the speed, as stated above.

In both cases, the electric motor and the gasoline engine, the invention allows the determination of the instantaneous Gesatmwirkungsgrades the boat drive. While driving, the efficiency of the boat drive can be determined and readjusted if necessary, for example in changing flow conditions.

Traditionally, in electric motors, the power rating is given by the current drawn from the battery multiplied by the battery voltage. So only the input power is given. All system losses are ignored.

To characterize internal combustion engines so far, the shaft power, which results from the product of torque and angular velocity at the propeller shaft, used. The often high losses of the propeller are not considered here.

The overall efficiency of a drive system results from the sum of the partial efficiencies of all components. Even a single poor partial efficiency significantly affects the overall efficiency. The invention allows the determination of the overall efficiency and thereby enables a continuous optimization of all components and their interaction.

Advantageously, the inventively determined efficiency for regulating and / or controlling the boat drive is used. It is particularly advantageous if the measurement of the thrust and the speed and the determination of the efficiency continuously or at regular intervals, for example, every minute.

In a preferred embodiment, when the inventive method shows a reduction in efficiency, the drive of the boat drive is influenced so that the efficiency returns to its earlier, higher value. When changing a parameter influencing the performance of the boat drive, for example, the fuel flow rate or the propeller speed, it can be determined directly whether this leads to an increase or decrease in the efficiency. Through targeted variation of individual parameters, it is possible to optimize the boat drive while driving.

Preferably, such an optimization takes place automatically, that is, individual relevant for the boat drive factors are each varied by a preset value and, depending on the effects of this variation on the efficiency, adjusted accordingly automatically, so that the drive is always driven with optimum efficiency ,

It has proven to be advantageous to store the measured and optionally the parameters calculated therefrom, such as thrust, speed and / or efficiency, at least temporarily. Based on the stored values, for example, after the trip a detailed analysis of the boat trip can be carried out and the boat drive and individual components of the boat drive and their interaction can be further optimized.

For example, the invention is suitable for optimizing the propeller. During test drives with differently designed propellers, the influence of the different types of propellers on the propulsion thrust achieved or on the efficiency of the boat propulsion system can be examined.

The control and regulation of the boat drive preferably takes place as a function of the efficiency determined according to the invention. Depending on the application, it may also be sufficient and reasonable to regulate the boat drive depending on the power used for the feed, without the exact efficiency would have to be calculated.

In the so-called displacement boats, the speed can not be increased substantially after reaching a certain maximum speed even with further increase in the drive power. An observation of the dependence of the speed of the boat on the power absorbed can serve as a first clue as to whether the maximum speed has already been reached. However, this simple monitoring of the speed-power dependency does not take into account, for example, changing flow conditions, which also affect boat speed. The regulation or control according to the invention depending on the efficiency of the boat drive, however, allows an optimized driving style.

The invention is basically suitable for all types of boat drives. Due to the limited capacity of batteries and rechargeable batteries, electric drives require a particularly high demand for optimized operation of the boat drive. The method according to the invention is therefore preferably used for the characterization of electric boost drives. But also in gasoline engines, the inventive method can be used with advantage. This applies regardless of whether the boat drive is designed as a propeller drive or in any other way. According to the invention, the actual thrust transmitted to the boat is determined, regardless of how it is generated.

The invention also relates to a propulsion system for a watercraft with a boat drive, in particular an outboard motor, and with fastening means connected to the boat drive for fastening the propulsion system to the vessel, wherein a force, traction or pressure measuring device is provided, which / the detected by the boat drive on the fasteners or on the watercraft applied (n) force, train or pressure.

The force, traction or pressure gauge provides a signal which is proportional to the thrust exerted by the boat propulsion on the vessel, either directly or indirectly via the attachment means. For this purpose, the force, traction or pressure measuring device is preferably installed on the holder or fastening of the boat drive on the watercraft.

In a preferred embodiment, the boat drive is arranged to be movable relative to the attachment means. Particularly preferably, the boat drive is attached to a tilting device, which allows a change in the inclination of the boat drive relative to the vessel. For outboard motors, for example, a shaft inclining device may be provided, which allows the setting of different angles of inclination between the shaft of the outboard motor and the stern of the boat. The outboard motor is held in the different positions by a locking device, such as a bolt. The force, tension or pressure measuring device according to the invention is in this case coupled directly to the locking device and absorbs the change in the force that is exposed to the locking device during operation of the boat drive.

Preferably, the device for determining the thrust force is self-sufficient, that is, independent of an external power supply executed. This can be realized, for example, by obtaining the energy necessary for determining the feed from the vibration of the boat drive during operation.

Particularly preferably, the invention is used in boats with an outboard drive. In this type of boat also a subsequent installation of a force, traction or pressure measuring device is readily possible. Outboard drives are usually provided with a suspension to hang the drive at the stern, especially at the boat mirror, and fix. The suspension has a shaft inclination device, whereby the boat drive can be brought into one or more tilted positions, for example for shallow water rides or to tilt the outboard motor completely out of the water.

The force, traction or pressure measuring device is preferably attached to the shaft inclination device. The shaft inclination device has a tilt axis about which the boat drive can be tilted, and an adjustable support to keep the boat drive in the desired tilted position. Preferably, a pressure measuring device is located between the boat drive and the support. The applied by the boat drive thrust is absorbed by the support and transmitted to the boat. By means of the pressure measuring device therebetween, the thrust force or a pressure proportional thereto can be determined and read out.

Numerous methods, for example taking advantage of the piezoelectric effect, can be used for pressure measurement.

Instead of a pressure or Kraftrnesseinrichtung, it is also possible to provide a Zugmesseinrichtung, for example in the form of a strain gauge. The tension measuring device is attached to a suitable component of the boat drive, so that acts on this a feed proportional to the traction.

Figur 1

einen Außenbordmotor mit einer Kraftübertragungsvorrichtung zur Durchführung des erfindungsgemäßen Verfahrens und

Figur 2

eine alternative Ausführung des Außenbordmotors.

The invention and further preferred embodiments of the invention are shown schematically in the following figures. Show here

FIG. 1

an outboard motor with a power transmission device for carrying out the method according to the invention and

FIG. 2

an alternative embodiment of the outboard engine.

The outboard motor shown in Figure 1 is used to drive a boat, of which only the boat mirror 1 for attachment of the outboard motor is shown in the figure. The outboard motor has an upper part 2, a shaft 3 and an underwater part or pylon 4 with a propeller 5. The outboard motor is designed as an electric motor and is powered by a located in the upper part 2 battery 13.

A U-shaped profile 6 is hung over the mirror 1 and mounted by means of a screw clamp-like clamping device 7 to the boat transom 1.

On the profile 6, a joint 8 is fixed, on which a sleeve 9 is rotatably mounted. The sleeve 9 surrounds and holds the shaft 3 of the outboard motor, so that the outboard motor can be tilted about the axis of rotation 8. At the lying on the outside of the boat leg 10 of the profile 6, a pressure transducer 11, for example, a piezoelectric element, attached.

During operation of the outboard motor, the propeller 5 generates a directed in the longitudinal direction 12 of the underwater part 4 thrust. The thrust of the propeller 5 is transmitted via the shaft 3, the joint 8 and the pressure transducer 11 to the boat and causes a forward movement of the boat.

The pressure measured by the pressure transducer 11 is proportional to the force generated by the propeller 5. From the surface of the pressure transducer 11 can also be closed in a simple manner to the force acting on the pressure transducer 11 force. The shaft 3 acts as a one-armed lever with the joint 8 as a rotation axis. By applying the leverage laws, the force generated by the propeller can be determined from the force measured at the pressure sensor 11 and the lever lengths a and a + b .

The pressure measured by the pressure transducer 11 is sent via a signal line 17 to an evaluation unit 18. The evaluation unit 18 is further supplied with a signal 19 which is proportional to the energy removed per unit time of the battery. In addition, the speed of the boat is determined via a log, not shown in the drawing or via a satellite navigation system, and fed via line 20 to the evaluation unit 18.

In the evaluation unit 18, the measured quantities of pressure and speed are used to calculate the energy per unit of time effectively transmitted by the engine to the boat and converted into feed, that is to say the service line. By dividing by the power drawn from the battery directly results in the efficiency of the engine. The thus determined efficiency is supplied via signal line 21 of the motor controller 22 and used for controlling and regulating the motor.

It is also possible to regulate the motor not on the efficiency, but in dependence on the feed generated. All of the evaluation unit 18 supplied and the calculated values in this are stored and can be used for later evaluations.

FIG. 2 shows a further embodiment of the invention. The same components are provided in both figures with the same reference numerals.

The drive system shown in FIG. 2 differs from that according to FIG. 1 in that the outboard motor can be brought into different positions by means of a shaft tilting device. For this purpose, the shaft inclining device has a base plate 14 with a plurality of bores 15 into each of which a matching pin 16 can be inserted. The shaft 3 of the outboard motor can be tilted about the axis of rotation 8 and, depending on which bore 15 of the bolt 16 is introduced, held in a certain position. In Figure 2, the vertical arrangement of the shaft 3 is shown.

The pressure sensor 11 is in this case preferably attached to the shaft 3 in such a way that the pressure transducer 11 between the shaft 3 and the stem 3 holding bolt 16 comes to rest and can measure the pressure occurring during operation of the outboard motor in addition to the weight of the outboard engine pressure ,

The control and regulation of the motor shown in Figure 2 can be carried out analogously to the control described with reference to FIG.

Claims (10)

A method of characterizing a boat propulsion driving a vessel, characterized in that the thrust exerted on the vessel by the boat propulsion is determined. A method according to claim 1, characterized in that the boat drive is controlled and / or regulated in dependence on the determined thrust. Method according to one of claims 1 or 2, characterized in that the speed of the watercraft is determined. A method according to claim 3, characterized in that the speed is determined by means of a satellite navigation system or by means of a log. Method according to one of claims 3 or 4, characterized in that the power transmitted by the boat drive to the vessel is determined from the thrust force and the speed. A method according to claim 5, characterized in that the efficiency of the boat drive from the ratio of the power transmitted to the vessel and the power absorbed by the boat drive power is determined. Method according to one of claims 1 to 6, characterized in that the boat drive is controlled so that the boat drive is operated with optimum efficiency. A method according to claim 7, characterized in that the boat drive is powered by an energy storage with energy, wherein the energy stored in the energy storage determined and determined from the speed achieved with optimum efficiency, the maximum range of the boat. Propulsion system for a watercraft with a boat drive, in particular an outboard motor, and fastening means (6, 7, 10, 14, 15, 16) with are connected to the boat drive and which serve for fastening the drive system to the vessel, characterized in that a force, traction or pressure measuring device (11) is provided, which / the from the boat drive on the fastening means (10, 16) or on the force, pull or pressure applied to the vessel. Drive system according to claim 9, characterized in that the boat drive is arranged to be movable relative to the fastening means.

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