BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to electronic shift and throttle systems and, in particular, to increasing and decreasing engine throttle. Description of the Related Art

[0002] Vehicles such as marine vessels are often provided with electronic shift and throttle systems. These systems typically allow an operator to control the shift and throttle functions of a propulsion unit using a control lever which is pivotally mounted on a control head. The control lever is moveable between a forward wide open throttle (forward WOT) position and a reverse wide open throttle (reverse WOT) position, through a neutral position. A controller reads the position of the control lever as the control lever moves through its operational range. The controller sends shift commands and throttle commands which drive a shift actuator and a throttle actuator based on the position of the control lever.

[0003] For example, United States Patent Number 7,330,782 issued on February 12, 2008 to Graham et al. and the full disclosure of which is incorporated herein by reference, discloses an electronic shift and throttle system in which a position sensor is used to sense the position of a control lever. The position sensor is electrically connected to an electronic control unit (ECU) and sends an electrical signal to the ECU. The ECU is able to determine the position of the control lever based on the voltage level of the electrical signal received from the position sensor. The ECU then determines the positions to which the output shafts of the shift actuator and the throttle actuator should be set. [0004] Each of the output shafts is also coupled to a corresponding position sensor. Electrical signals sent by these position sensors may be used to determine the positions of the output shafts. This feedback may be used to govern the ECU. This is beneficial because variances and play between components used to link throttle actuators to throttles make it desirable to calibrate throttle controls. Calibrated throttle controls allow an operator to more accurately increase or decrease engine throttle in a marine vessel.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide an improved method and system for increasing or decreasing engine throttle in a marine vessel. [0006] There is accordingly provided a method of adjusting engine throttle in an electronic shift and throttle system. The method comprises determining a position of a control lever which allows an operator to manually control throttle functions. A throttle command is calculated based on the position of the control lever. The throttle command is adjusted in response to an input received from an input means. The position of the control lever remains constant as the throttle command is being adjusted.

[0007] In a one embodiment of the method, the throttle command is calculated using a throttle curve and the throttle command is adjusted by 1% in response to each input received from the input means to a maximum of 5%. In another embodiment of the method, the throttle command is adjusted by 0.5% in response to each input received from the input means to a maximum of 10%. The throttle command may be increased or decreased. The throttle command is only adjusted if all running engines are in forward gear and the adjusted throttle signal is sent to engine controllers of all running engines. The adjusted throttle command is cancelled when the control lever is moved.

[0008] Also provided is an electronic shift and throttle system which comprises a control head including a pivotable control lever for manually controlling throttle functions of an engine. The control lever is moveable through a range of positions. The engine includes a throttle and a throttle actuator for moving the throttle between an idle position and a wide open throttle position. An engine control unit provides a throttle command causing the throttle actuator move the throttle based on a position of the control lever. An input means is provided to allow an operator to increases or decrease the throttle command without having to move to control lever. Preferably the input means is a button disposed on the control head.

[0009] The present invention provides an improved system and method for increasing or decreasing engine throttle which allows an operator fine tune engine throttle. The present invention also allows an operator increase or decrease engine throttle without having to move a control lever. BRIEF DESCRIPTIONS OF DRAWINGS

[0010] The invention will be more readily understood from the following' description of the embodiments thereof given, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a marine vessel provided with a plurality of propulsion units and an improved electronic shift and throttle system;

Figure 2 is a side view of an engine of one of the propulsion units of Figure 1 ;

Figure 3 is a top view of the a control head of the marine vessel of Figure 1 ;

Figure 4 is a schematic diagram illustrating the electronic shift and throttle system of Figure 1 ;

Figure 5 is an elevation view of the control head of Figure 3 illustrating an operational range of a control lever thereof;

Figure 6 is a table illustrating the lighting of indicator or gear lamps as the control lever of Figure 5 is moved through the operational range; Figure 7 is side elevation view of a shift actuator of the propulsion unit of Figure 2 illustrating an operational range of an actuator arm thereof;

Figure 8 is a side elevation view of a throttle actuator of the propulsion unit of Figure 2 illustrating an operational range of an actuator arm thereof; Figure 9 is a side elevation view of the throttle actuator of Figure 8 illustrating a second side thereof;

Figure 10 is a perspective view of the throttle actuator of Figure 8 illustrating the first side thereof;

Figure 1 1 is a perspective view of the throttle actuator of Figure 8 illustrating the second side thereof;

Figure 12 is a sectional view taken along line A-A of Figure 1 1 ;

Figure 13 is a fragmentary side view, partially in section and partly schematic, of the throttle actuator of Figure 8, a throttle, and a linkage therebetween;

Figure 14 is a sectional view of the throttle of Figure 13 illustrating the throttle in an idle position;

Figure 15 is a sectional view of throttle of Figure 13 illustrating the throttle in a wide open throttle (WOT) position;

Figure 16 is a sectional view of throttle of Figure 13 illustrating movement of the throttle as the throttle controls are being calibrating; and Figure 17 is a flow chart illustrating the logic of a throttle calibration method disclosed herein; Figures 18A and 18B are charts illustrating a plurality of forward throttle curves;

Figure 19A and 19B are charts illustrating a plurality of reverse throttle curves; and

Figure 20 is a plan view of a switch panel which supports an RPM adjustment input means. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Referring to the drawings and first to Figure 1 , this shows a marine vessel 10 which is provided with a plurality of propulsion units in the form of three outboard engines 12a, 12b and 12c. However, in other examples, the marine vessel 10 may be provided with any suitable number of inboard and/or outboard engines. It is common to see two engines and practically up to five engines in pleasure marine vessels. The marine vessel 10 is also provided with a control head station 14 that supports a control head 16. The control head 16 is provided with a microprocessor (not shown).

[0012] A first one of the engines, namely the port engine 12a, is best shown in Figure 2. The port side engine 12a includes a shift actuator 18a, a throttle actuator 20a, and an electronic servo module (ESM) 22a; all of which are disposed within a cowling 24. Second and third ones of the engines, namely the center engine 12b and starboard 12c engine, have substantially the same structure as the port engine 12a and are accordingly not described in detail herein. [0013] The control head 16 is best shown in Figure 3. The control head 16 includes a housing 26. A port control lever 30 and starboard control lever 40 are each pivotally mounted on the housing 26. The port control lever 30 normally controls the shift and throttle functions of the port engine 12a but, in this example, also controls the shift and throttle functions of the center engine 12b both of which are shown in Figure 1. The starboard control lever 40 controls the shift and throttle functions of the starboard engine 12c which is also shown in Figure 1. In a marine vessel with five engines, the port control lever would control the shift and throttle functions of the port, center port and center engines while the starboard control lever would control the shift and throttle functions of the starboard engine and starboard center engine.

[0014] The port control lever 30 is provided with a master trim switch 50 which allows an operator to simultaneously trim all of the engines. The port and starboard engines are trimmed individually using a respective port trim button 31 and starboard trim button 41, which are both disposed on the housing 26. The center engine 12b is under the control of a center trim button 31 (not shown).

[0015] The housing 26 also supports a plurality of indicator or gear lamps which, in this example, are LED lamps. A port forward indicator 32, port neutral indicator 34, and port reverse indicator 36 are disposed on a side of housing 26 adjacent the port control lever 30. A starboard forward indicator 42, starboard neutral indicator 44, and a starboard reverse indicator 46 are disposed on a side of housing 26 adjacent the starboard control lever 40. A port neutral input means 38 and starboard neutral input means 48 are also disposed on the housing 26. An RPM input means 52, synchronization (SYNC) input means 54, and SYNC indicator lamp 56 are also all disposed on the housing 26. In this example, the port neutral input means 38, starboard neutral input means 48, RPM input means 52, and SYNC input means 54 are buttons but any suitable input devices may be used.

[0016] As best shown in Figure 4, the control head 16 and the engines 12a, 12b and 12c, together with their corresponding shift actuators 18a, 18b and 18c; throttle actuators 20a, 20b and 20c; and ESMs 22a, 22b and 22c, form part of an electronic shift and throttle system 60. The electronic shift and throttle system 60 further includes a gateway 62 and a plurality of engine management modules (EMMs) 64a, 64b and 64c. Each EMM is associated with a corresponding ESM. The control head, gateway, ESMs, and EMMs communicate with each other over a private CAN network 66. The electronic shift and throttle system 60 is designed to support two control heads and control up to five engines. Components of optional fourth and fifth engines 12d and 12e as well as an optional second control head 17 are shown in ghost. [0017] A single master ignition switch 68 provides power to the entire private CAN network 66. However, start and stop functions are achieved by individual switches 70 read by the control head 16 as discrete inputs or serial data. Any command an operator inputs to the control head 16 to start, stop, trim, shift or accelerate one of the engines 12a, 12b or 12c is sent to the corresponding ESM 22a, 22b or 22c and corresponding EMM 64a, 64b or 64c over the CAN network 66. The ESMs and EMMs are each provided with a microprocessor (not shown). In this example, a private network cable 72 that carries the CAN lines from the control head 16 to the engines 12a, 12b and 12c has two separate wires used to shut down the engines in the event that the CAN network 66 fails.

[0018] Information from the electronic shift and throttle system 60 is made available to devices on a NMEA2K public network 74 through the gateway 62. The gateway 62 isolates the electronic shift and throttle system 60 from public messages, but transfers engine data to displays and gauges (not shown) on the public network 74. The gateway 62 is also provided with a plurality of analog inputs 76 which may be used to read and broadcast fuel senders or oil senders or other resistive type senders such as rudder senders or trim tab senders on the public network 74.

[0019] Referring now to Figure 5, the port side 30 control lever is moveable between a forward wide open throttle (forward WOT) position and a reverse wide open throttle (reverse WOT) position, through a neutral position. An operator is able to control the shift and throttle functions of the port engine 12a by moving the port control lever 30 through its operational range. The port control lever 30 is also provided with a forward detent, neutral detent, and reverse detent all disposed between the forward WOT position and reverse WOT position. This allows the operator to physically detect when the port control lever 30 has moved into a new shift/throttle position. As shown in Figure 6, the port forward indicator 32, port neutral indicator 34, and port reverse indicator 36 light up to reflect the position of the port control lever 30 shown in Figure 5.

[0020] Referring back to Figures 4 and 5, the microprocessor supported by the control head 16 reads the position of the port control lever 30 and sends shift and throttle commands to the ESM 22a via the private CAN network 66. The ESM 22a commands the shift actuator 18a and throttle actuator 20a which are best shown in Figures 7 and 8, respectively. Figure 7 shows that the shift actuator 18a has an actuator arm 19a which is moveable between a forward position and a reverse position with a neutral position therebetween. Figure 8 shows that the throttle actuator 20a has an actuator arm 21a which is moveable between an idle position and a wide open throttle (WOT) position. An actuator position sensor 142, shown in Figure 12, signals the actuator position to the ESM 22a shown in Figure 4. This feedback may be used to govern the control head 16. The shift and throttle functions of the port side engine 12a are thereby controlled.

[0021] It will be understood by a person skilled in the art that the shift and throttle functions of the starboard engine 12c are controlled in a similar manner using the starboard control lever 40 shown in Figure 2. The shift and throttle functions of the center engine 12b are under the control of the port control lever 30 in this example. Accordingly, as thus far described, the electronic shift and throttle system 60 is conventional.

[0022] However, the electronic shift and throttle control system 60 disclosed herein is provided with an improved shift actuator 18a and throttle actuator 20a as shown in Figures actuators as shown in Figures 7 and 8 respectively. The shift and throttle actuators are both rotary actuators which have substantially the same structure and function in substantially the same manner, with the exception of the actuator arm 19a or 21a. This will be understood by person skilled in the art. Accordingly, only the throttle actuator 20a is described in detail herein.

[0023] Referring to Figures 7 through 1 1 , the throttle actuator 20a of the port engine 12a is shown in greater detail. The throttle actuator 20a generally includes a waterproof housing 1 12 which encases various components, a motor 1 14 extending from and bolted to the housing 1 12, and a harness 1 16 for electrically connecting the throttle actuator 20a to the electronic shift and throttle system 60. The housing 1 12 is provided with a plurality of mounting holes 1 18a, 1 18b, 1 18c, and 1 18d allowing the throttle actuator 1 12 to be mounted as needed. In this example, the housing 1 12 also includes a body 120 and a cover 121 bolted the body 120. Removing the cover 121 provides access to the various components encased in the housing 1 12. The motor 1 14 may be rotated in either a first rotational direction or a second rotational direction opposite to the first direction depending on the direction of the electric current supplied to the motor 1 14. As best shown in Figure 1 1 , the harness 16 is wired to the motor 1 14 and supplies an electric current thereto.

[0024] Referring now to Figure 12, the housing 1 12 encases a worm gear 122 which is coupled to an output shaft (not shown) of the motor 1 14. The worm gear 122 engages a worm wheel 124 which is integrated with a spur gear pinion 126. The worm gear 122 imparts rotary motion to both the worm wheel 124 and spur gear pinion 126. The spur gear pinion 126 imparts rotary motion to a sector spur gear 128 which is integrated with an output shaft 130 of the throttle actuator 20a. The output shaft 130 is thereby rotated by the motor 1 14. Bearings 132a and 132b are provided between the output shaft 130 and the housing 1 12 to allow free rotation of the output shaft 130 within the housing 1 12. A sealing member in the form of an O-ring 134 is provided about the output shaft 130 to seal the housing.

[0025] As best shown in Figure 1 1 , the distal end 136 of the output shaft 130 issplined. There is a longitudinal, female threaded aperture 138 extending into the output shaft 130 from the distal end 136 thereof. The aperture 138 is designed to receive a bolt to couple the output shaft 130 to the actuator arm 21a as shown in Figure 8. Referring back to Figure 12, there is a magnet 140 disposed at a proximal end 141 of the output shaft 130. There is also a position sensor 142 which senses a position of the magnet 140 as the output shaft 130 rotates. The position sensor 142 is thereby able to determine the rotating position of the output shaft 142. In this example, the position sensor 142 is a Hall Effect sensor but in other embodiments the sensor may be a magnetoresi stive position sensor or another suitable magnetic rotational sensor. The position sensor 142 is mounted on a circuit board 144 which is mounted on the throttle actuator housing 1 12. More specifically, in this example, the circuit board 144 is mounted on the housing cover 121. As best shown in Figures 9 and 10, the circuit board 144 is wired to the harness 1 16 allowing the position sensor 142 to send an electrical signal to the ESM 22a which is shown in Figure 4. [0026] As best shown in Figure 13, the actuator arm 21a is coupled to a throttle 150 of the port engine 12a, shown in Figure 2, by a throttle linkage 152. The throttle 150 includes a throttle body 154 and a throttle plate 156 mounted on a rotatable throttle shaft 158. There is also a throttle position sensor (TPS) 159 mounted on top of the throttle shaft 158 which senses the position of the throttle shaft as it rotates. In this example, the TPS 159 is a potentiometer and communicates with the EMM 64a shown in Figure 4. Together the plate 156, the shaft 158 and the TPS 159 form a butterfly valve member which is spring loaded to a closed position shown in Figure 14. Referring back to Figure 13, rotation of the actuator output shaft 130 drives the actuator arm 21a to rotate the throttle shaft 158. Rotation of the throttle shaft 158 causes the throttle 150 to move between an idle position shown in Figure 14 and a WOT position shown in Figure 15. Whether the throttle 150 is in the idle position or WOT position is dependent on the rotational position of output shaft 130. The throttle actuator 20a is an external actuator, the electronic shift and throttle system 60 may be installed as a kit on an existing engine.

[0027] To correlate position of the throttle 150 with the position of the actuator arm 21a, it is necessary calibrate the throttle controls of the electronic shift and throttle system 60. Once calibrated, the idle position of the actuator arm 21a will correspond to the idle position of the throttle 150. [0028] The ESM 22a, shown in Figure 4, calibrates the throttle controls by using the voltage level sent by the TPS 159, the duty cycle of the electrical signal sent by the actuator position sensor 142 and the amount of current flowing into the actuator motor 1 14. The voltage level of TPS 159 varies with the position of the throttle plate 156. In this example, the voltage level of TPS 159 is low when the throttle plate 156 is perpendicular and in contact with throttle housing 154, as shown in Figure 14, and the voltage level of the TPS 159 is high when the throttle plate 156 is parallel with throttle housing 154 as shown in Figure 15. The duty cycle of the electrical signal sent by the actuator position sensor 142 varies with the position of the throttle actuator arm 21a. In this example and as shown in Figure 13, the duty cycle of position sensor 142 is low when the actuator arm 21a at the idle position and is high when the actuator arm 21a is at the WOT position. The amount of current flowing into the actuator motor J 14 is low when the actuator arm 21a moves freely and increases when the throttle plate 156 is in contact with the throttle housing 154 thereby stalling the motor 1 14.

[0029] The ESM 22a calibrates the throttle controls by determining the throttle position where the TPS voltage is the lowest, while avoiding residual tension in the throttle linkage 152. This is done by 20 opening the throttle 150 and moving it back to the idle position in increments. This is best shown in ghost in Figure 16. The ESM 22a controls the opening of the throttle 150 and moves the throttle 150 back to the idle position. In this example, the throttle 150 is moved back in increments of 1° towards a hard stop, i.e. where the throttle plate 156 comes into contact with the throttle housing 154. At each increment the ESM 22a communicates 25 with the EMM 64a and requests the voltage level of the TPS 159 shown in Figure 13. The ESM 22a stores the value. This is repeated until the throttle plate 156 comes to the hard stop. The ESM 22a determines if the throttle 150 is at the hard stop by measuring the current flowing in the actuator motor 1 14. The ESM 22a assumes that the throttle 150 is at the hard stop if the current is above a pre-determined value. The ESM 22a then establishes the idle position as being where the lowest valid voltage level that is at least a minimal distance away from hard stop was measured. The minimal distance from the hard stop ensures that the tension created in the throttle linkage 152 while moving the throttle plate 156 against the hard stop is released. In this example, the minimal distance is defined in degrees and set to 0.75°. However, the minimal distance may range for example between 0.3° and 1.5°.

[0030] In this example, the calibration procedure will terminate successfully if the following parameters are met: 1. The voltage level of the signal from the throttle position sensor has changed more than the movement amount while calibrating (in this example 0.2V). This amount confirms the actuator actually moved the throttle plate.

2. The minimum expected idle position voltage level (in this example 0.3V) <= the voltage level of the signal from the throttle position sensor in the idle position <= the maximum expected idle position voltage level (in this example 0.62V).

The values may vary in other embodiments.

[0031] Figure 17 best shows the above described calibration procedure. The new calibration position is stored in EEPROM if the calibration procedure terminates successfully. A similar calibration procedure is used for the center and starboard engines.

[0032] Referring back to Figure 3, once the calibration procedure is completed the operator can more accurately increase or decrease the engine throttle by moving the port control lever 30 or starboard control lever 40 through its operational range, knowing the exact location of the idle position. The control head 16 uses a throttle curve to determine a throttle command based on the position of the control lever. A throttle curve is a two dimensional table which defines a relationship between a throttle value determined from the position of the control lever and the actual command sent to an ESM 22a, 22b or 22c shown in Figure 4. In the electronic shift and throttle system disclosed herein a throttle curve is defined with five points. Interpolation is used to calculate the throttle command for control lever positions that fall in between the points. As shown in Figures 18 and 19, in this example, the control head 16 holds a total of eight forward throttle curves and eight reverse throttle curves. However, the control head 16 only uses one forward throttle curve and one reverse throttle curve at any given time. The default forward throttle curve is forward throttle curve number six. The default reverse curve is reverse throttle number six. The throttle curves being used can be selected by changing the control head settings.

[0033] The operator can also increase and decrease engine throttle without having to move the control levers 30 and 40 shown in Figure 3. The RPM input means 52 of the control head 16 includes an RPM+ input means 51 which increases engine speed and RPM- input means 53 which decreases engine speed. In this example, the RPM+ input means and RPM- means are buttons but any suitable input devices may be used. Pressing the RPM+ input means 51 increases the throttle command sent through the CAN network to the ESM by a predetermined amount, e.g. 0.5% to 1%. Increasing the engine throttle with the predetermined amount, e.g. 0.5%, normally results in a repeatable amount of engine RPM increase, e.g. 50 RPM when the vessel is on plane. Pressing the RPM- input means 53 decreases the throttle command sent through the CAN network to the ESM by a predetermined amount, e.g. 0.5% to 1%. The increases and decreases to the throttle command are added to the throttle command as determined based on the position of the control lever and the throttle curve being used. The throttle command is only adjusted when all running engines are in the forward gear. The adjusted throttle command is applied to all running engines. [0034] In this example, the throttle command adjustment is limited to a 5% adjustment. Pressing the RPM+ input means 51 when the throttle command has already been increased by 5% or the throttle reaches 100% will not result in further adjustment. Similarly, pressing the RPM- input means 53 when the throttle command has already been decreased by 5% or the throttle reaches 0% will not result in further adjustment. A throttle command of 0% corresponds to the idle position and a throttle command of 100% corresponds to the WOT position.

[0035] Moving either of the control levers 30 or 40 in any direction cancels the adjusted throttle command and disengages the adjustment function. The throttle command is then based on the position of the control levers 30 or 40 and the throttle curve being used. The new throttle command may be also be adjusted by pressing the RPM+ input means 51 or RPM- input means 53 as required. Accordingly, the electronic shift and throttle system disclosed herein allows the operator finely increase or decrease engine throttle. The electronic shift and throttle system disclosed herein also allows the operator increase or decrease engine throttle without having to move a control lever.

[0036] In this example, the throttle command may be adjusted by 5%. The total adjustment can be defined as an adjustment range required to change engine RPM. The optimal adjustment range is between 3% and 10%. The lower limit of the optimal adjustment range provides enough adjustment change engine RPM. The upper limit of the optimal adjustment range ensures that when the RPM adjustment function is disengaged, the increase or decrease to engine RPM is not too large and remains predictable.

[0037] In other embodiments, as shown in Figure 20, an RPM input means 252 can be mounted on a switch panel 255. A new throttle command is adjusted by pressing the RPM+ input means 251 or RPM- input means 53 as required. The enable button 260 activates the feature while the cancel button 270 deactivates the feature. The switch panel 252 may be mounted anywhere on a marine vessel as an aftermarket accessory. For example, the switch panel 252 may be mounted on the dock or stern to allow fine adjustment of the throttle command. Fine control of the engine speed is important, especially while trolling or water skiing.

[0038] It will be understood by a person skilled in the art that the method and system for increasing or decreasing engine throttle disclosed herein may be implemented in any electronic shift and throttle control system, regardless of whether the vehicle is a marine vessel.

[0039] It will further be understood by a person skilled in the art that many of the details provided above are by way of example only, and are not intended to limit the scope of the invention which is to be determined with reference to following claims.