Information
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Patent Grant
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6536402
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Patent Number
6,536,402
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Date Filed
Friday, May 4, 200123 years ago
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Date Issued
Tuesday, March 25, 200321 years ago
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Inventors
-
Original Assignees
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Examiners
- Yuen; Henry C.
- Huynh; Hai
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CPC
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US Classifications
Field of Search
US
- 123 352
- 123 435
- 123 436
- 123 472
- 123 480
- 123 689
- 123 679
- 123 481
- 123 198 D
- 123 198 DB
- 701 104
- 701 110
- 701 84
- 417 212
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International Classifications
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Abstract
An engine control system, dredging system, and a method for controlling torque output of an engine. An engine control system controls torque output of an engine. At least one sensor is coupled with the engine. The sensor monitors and transmits operating data of the engine. An electronic device coupled to the sensor is operable to control the engine as a function of the transmitted operating data. The engine is controlled by the electronic device to operate substantially at a predetermined torque limit over a predetermined range of engine speeds, by determining and regulating an amount of fuel to the engine. Alternatively, the engine is controlled by the electronic device to operate substantially at, and between predetermined upper and lower torque limits over a predetermined range of engine speeds, by determining and regulating an amount of fuel to the engine.
Description
TECHNICAL FIELD
The present invention relates to an engine control system, a method for controlling an engine, and a dredging system using the engine control system, and in particular to a programmable engine control system, dredging system, and method in which engine torque can be controlled and monitored over a predetermined range of engine speeds.
BACKGROUND
Dredging is an activity performed in a river or canal etc., where a boat has an engine which drives a pump that, in effect, sucks material from the bottom of the river to increase the depth of the river. In a dredging operation, a pump, such as a centrifugal pump is used, in which an impeller within the pump casing expels by centrifugal action a mixture of solids, water, and gases. As a partial vacuum is created within the pump, atmospheric pressure on the outside water surface along with the weight of the water itself (hydrostatic pressure) both act to force water and suspended solids from the bottom of a river or channel through the suction pipe into the pump. In this type of dredging, the materials emerging from the pump are placed onto barges or through another pipe to the shore.
In operation, the engine of the boat is used to run the dredging machinery, as well as used for its normal function of driving the propeller of the boat. When a dredging operation begins, the engine is connected to a shaft driving the dredging pump, and to the propeller. The engine can also be connected to other devices, such as a generator, to provide power as needed to these devices, even if the power is needed simultaneously. If the engine is configured to drive multiple devices (e.g., the torque limit is set to enable the engine to drive multiple devices), if one of the devices cuts off (e.g., the propeller is stopped), all of the engine torque is provided to the remaining device, e.g., shaft of the dredge pump, and the shaft of the dredge pump is unable to withstand such torque and accordingly, shaft or pump damage results.
SUMMARY OF THE INVENTION
The present invention relates to an engine control system, a method for controlling an engine, and a dredging system using the engine control system, and in particular to a programmable engine control system, dredging system, and method in which engine torque can be controlled and monitored over a predetermined range of engine speeds.
An engine control system controls torque output of an engine. At least one sensor is coupled with the engine. The sensor monitors and transmits operating data of the engine. An electronic device coupled to the sensor is operable to control the engine as a function of the transmitted operating data.
The engine is controlled by the electronic device to operate substantially at a predetermined torque limit over a predetermined range of engine speeds, by determining and regulating an amount of fuel to the engine. Alternatively, the engine is controlled by the electronic device to operate substantially at, and between predetermined upper and lower torque limits over a predetermined range of engine speeds, by determining and regulating an amount of fuel to the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of the present invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1
illustrates an engine control system for controlling torque output of an engine according to a first embodiment of the present invention;
FIG. 2
illustrates an electronic device according to one embodiment of the present invention;
FIG. 3
illustrates an engine control system for controlling torque output of an engine according to a second embodiment of the present invention;
FIG. 4
illustrates a dredging system according to an embodiment of the present invention
FIG. 5
is a block diagram depicting a method for controlling engine torque of an engine according to one embodiment the present invention.
DETAILED DESCRIPTION
While the invention described herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown solely by way of example in the drawings and are herein described in detail. It should be understood, however, that there is no intent to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
FIG. 1
displays an engine control system
10
for controlling torque output of an engine
20
according to a first embodiment of the present invention. An optional display
30
shows engine operating data, such as engine speed, as well as system operating data, such as torque limits of the engine, pump fluid flow, pressure of fluids in the system, fuel quantity, temperature of system components, etc. This engine and system operating data may be displayed to an operator, in for example, the pilothouse of a boat by ways known to those skilled in the art. In this example, the system envisioned consists of components such as the engine
20
, a dredge pump, connecting shafts, boat propeller, boat electrical and hydraulic systems, etc., (not shown), which are used during dredging operations.
In this embodiment, an input device
40
, such as a switch, is activated for setting a fixed torque limit of the engine. In other embodiments the input device may be some type of sensor that transmits an activation signal indicative of a predetermined condition being detected. This would in effect, automatically activate the torque limiting. Other embodiments may not use any input or activation device, thus keeping the torque limiting function constantly active. During system operation, e.g., during dredging, sensors
50
attached to the aforementioned system components monitor and collect the engine operating data, as well as the system operating data which may then be transmitted to the display
30
and to an electronic device
60
, such as, for example, a programmable electronic controller. The electronic device
60
controls the engine to operate at the torque limit which was set using input device
40
over a predetermined range of engine speeds, by controlling and regulating the amount of fuel needed by the engine
20
in order to maintain the torque limit. The predetermined range of speeds typically depends on.engine design. For example, a CAT 3500B engine available through Caterpillar Inc. is capable of operating in a range of 0 to 2400 rpm. Accordingly, the present invention allows for torque to be controlled over multiple engine speeds, as opposed to fixed engine speeds. Also in this embodiment, the set torque may be stored in memory or storage device
70
, which may be integrated with the electronic device
60
, although it need not be.
FIG. 2
illustrates an electronic device
60
according to one embodiment of the present invention. The electronic device
60
contains a computer readable medium
70
, on which is stored a computer program
80
. The computer program
80
stores instructions
90
which include maps
100
based on engine temperature. The maps
100
may include torque maps, torque limit maps, and timing maps, and may be used by the electronic device
60
to determine an amount of fuel needed by the engine
20
in order to maintain the torque limit. The instructions
90
and maps
100
can be developed based on engine empirical data, and programmed into a language understandable by the electronic device
60
.
In one embodiment of the present invention, the maps
100
can be based on temperatures of the engine, such as low, medium, and high (e.g., cold, warm, hot) temperatures. As an example, maps based on 30 ° C., 60° C., and 90° C. SCAC temperature may be used. Multiple temperature maps may be used because when some large engines operate at a low engine temperature, for example, at a start-up condition, more fuel may be required to maintain a constant torque for the engine, than when the engine is operating at a high temperature. Including a plurality of maps at engine operating set points such as the temperatures described above enables the electronic device
60
to regulate fuel accordingly. Alternatively, only a single temperature map may be used, of course.
Further, the instructions
90
may also be capable of interpolating and extrapolating the maps
100
for engine temperatures falling between or outside of the maps
100
to determine a sufficient fuel quantity or fuel position, i.e., rack value at these temperatures. In addition, the instructions
90
may also include a feature wherein when a system sensor
50
indicates an out-of normal operating condition, e.g., if coolant temperature fails, a shaft or oil line breaks, or a pump malfunctions, etc., the electronic device
60
defaults to use the maps
100
based on a low temperature of the engine
20
. As discussed above, using this lower temperature map would encourage more fuel to be provided to the engine, which is useful in helping maintain essential boat systems until the out-of normal operating condition can be examined.
Further, instructions
90
may also include a feature wherein when sensors
50
indicate that a predetermined engine or operating condition occurs, e.g., a pump is activated, control of engine torque is automatically initiated. Sensors
50
would, for example, measure current or voltage conditions of a system component, rotation of a shaft, etc., for sensing this predetermined condition. This later feature of the electronic device
60
may reduce the amount of operator time required to operate the system. In addition, the input device
40
, as described above, may be eliminated from the engine control system
10
.
A second embodiment of an engine control system
200
of the present invention is shown in FIG.
3
. Items shown in
FIG. 3
that are essentially similar to those shown in
FIG. 1
, retain their same numerical identification. As shown in
FIG. 3
, the second embodiment of the present invention includes an input device
110
which may set upper and/or lower torque limits of the engine
20
. The electronic device
60
controls the engine
20
to operate between the upper and lower torque limits using the transmitted system operating data. Either of the aforementioned embodiments may also include a feature whereby the highest torque limit that can be input typically cannot exceed maximum torque speed of the engine (typically at “peak torque speed”). Likewise, the input device
110
and instructions
90
of the electronic device
60
may be used to limit the lowest torque limit that an operator can input as a torque value. One of ordinary skill in the art will recognize that input device
110
can include among other things, a control at the pilothouse for setting the torque limits, an input device on the electronic device
60
itself for setting the torque limits, or a wireless transmitter which transmits the torque limits to the electronic device
60
. The wireless solution may allow the pilot to control dredging operations from the deck of the boat, as well as the pilothouse.
In one embodiment of the present invention, the engine control system
10
,
200
may also contain a recorder
120
that records the system operating data that can be used, for example, to review operator practices, streamline trouble-shooting, and speed up service. In addition, other embodiments may include a warning device
130
that warns the operator of any non-standard operating condition, and an operator override switch
140
that overrides the electronic device
60
. The operator override switch
140
shown in this embodiment may be integrated into the input device
110
, although it need not be.
A dredging system
300
according to one embodiment of the present invention is shown in FIG.
4
. Here again, items shown in
FIG. 4
that are essentially similar to those shown in
FIG. 1
, retain their same numerical identification. In the dredging system
300
, the engine
20
supplies power to the dredging system
300
and to a pump
150
. The pump
150
may be driven by shaft
160
connected to the engine
20
. The pump
150
displaces material, such as, for example, sediment from the bottom of a river. During a dredging operation, an electronic device
60
, such as, for example, the one discussed above controls the engine
20
at a torque limit over a predetermined range of engine speeds, by determining and regulating an amount of fuel to the engine. In this embodiment, when the pump
150
is activated, the electronic device
60
may derate the engine
20
. Of course, upper and lower torque limits may also be set and controlled by the electronic device
60
.
FIG. 5
discloses a method for controlling engine torque of an engine according to one embodiment of the invention. Once for example, a dredging operation is begun, the operator, as shown in block
1
, sets a fixed torque limit. As indicated in block
2
, the system is monitored during the dredging operation and system operating data is continually transmitted to, for example, an electronic device of the present invention. Block
3
shows that the engine is controlled, using the transmitted system operating data, to operate at the fixed torque limit over a predetermined range of engine speeds. The method may include a decision feature as shown in block
4
, wherein if a non-standard system condition is detected by the sensors, a warning device may be activated to warn the operator of a non-standard system operating condition, and the electronic device may derate the engine accordingly as indicated in block
5
.
In another method of the present invention, instead of setting a fixed torque limit as described above, the operator may set upper and lower torque limits, and the electronic device controls the engine to operate at, and between the upper and lower torque limits. Accordingly, this method allows flexibility in performing, for example, dredging operations, based on this torque range.
Industrial Applicability
In practice, during dredging operations, an engine
20
may be configured to drive multiple devices (e.g., the torque limit is set to enable the engine to drive multiple devices). When activated, such as by the input device, an electronic device
60
controls the engine
20
to operate at a predetermined torque limit, or controls the engine
20
to operate at, and between upper and lower torque limits. If a system sensor
50
indicates an out-of normal operating condition, the electronic device
60
may derate or cut-off the engine
20
. The electronic device
60
includes a computer readable medium
70
, on which is stored a computer program
80
used for controlling the engine. The computer program
80
stores instructions
90
which include torque maps based on engine temperature. These maps
100
are used in determining an amount of fuel needed by the engine
20
in order to maintain the fixed torque limit over a predetermined range of engine speeds, or to maintain the engine at, and between the two torque limits.
Claims
- 1. An apparatus for controlling the torque output from an engine comprising:at least one torque receiving device coupled with the engine to receive a first portion of the torque output from the engine when at least one of the at least one torque receiving device is operating and operable to receive a second portion of the torque, the second portion being less than the first portion, when at least one of the at least one torque receiving device is not operating; at least one sensor coupled with the at least one torque receiving device, the at least one sensor operable to transmit a first signal indicative of whether at least one of the at least one torque receiving device is operating; a pump coupled with the engine to receive a third portion of the torque output from the engine; and an electronic device coupled with the first sensor to receive the first signal, the electronic device operable to transmit a second signal operable to reduce the amount of torque output by the engine when the first signal indicates that at least one of the at least one torque receiving device is not operating.
- 2. The apparatus of claim 1 wherein the electronic device is operable to transmit the second signal when the first signal indicates that at least one of the at least one torque receiving device is not operating and when the third portion of torque is a quantity of torque that would cause damage to the pump.
- 3. The apparatus of claim 2 wherein the electronic device is not operable to transmit the second signal when the third portion of torque is not a quantity of torque that would cause damage to the pump.
- 4. The apparatus of claim 1 wherein the second signal is operable, when the at least one of the torque receiving device is not operating, to reduce the third portion of the torque received by the pump to be a quantity less than a quantity of torque that would cause damage to the pump.
- 5. The apparatus of claim 1 wherein the second signal is operable, when the at least one of the torque receiving device is not operating, to reduce the amount of torque output by the engine to a quantity less than a quantity of torque that would cause damage to the pump.
- 6. The apparatus of claim 1 wherein the second signal is operable to control the amount of fuel delivered to the engine.
- 7. The apparatus of claim 1 wherein the at least one torque receiving device comprises a propeller.
- 8. The apparatus of claim 1 wherein the sum of the second portion and the third portion is substantially equal to the total torque output from the engine.
- 9. The apparatus of claim 1 wherein the sum of the first portion and the third portion is substantially equal to the total torque output from the engine.
- 10. A method for controlling the torque output from an engine having a pump and at least one other torque receiving device operable to receive torque from the engine, comprising:determining whether the at least one other torque receiving device is receiving torque from the engine; and reducing the amount of torque output from the engine when the at least one of the other torque receiving device is not receiving torque from the engine.
- 11. The method of claim 10 wherein reducing the amount of torque output from the engine comprises:reducing the amount of torque output from the engine when the at least one of the other torque receiving device is not receiving torque from the engine and the quantity of torque received by the pump if the reduction in torque output by the engine did not occur would be a quantity of torque that would cause damage to the pump.
- 12. The method of claim 10 wherein at least one of the at least one other torque receiving devices comprises a propeller.
US Referenced Citations (22)
Foreign Referenced Citations (1)
Number |
Date |
Country |
141373 |
May 1999 |
JP |