GB2186089A - Monitoring system for a fuel- injection engine - Google Patents
Monitoring system for a fuel- injection engine Download PDFInfo
- Publication number
- GB2186089A GB2186089A GB08701031A GB8701031A GB2186089A GB 2186089 A GB2186089 A GB 2186089A GB 08701031 A GB08701031 A GB 08701031A GB 8701031 A GB8701031 A GB 8701031A GB 2186089 A GB2186089 A GB 2186089A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pulses
- pressure sensitive
- periodicity
- pipe
- engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000002347 injection Methods 0.000 title claims abstract description 29
- 239000007924 injection Substances 0.000 title claims abstract description 29
- 238000012544 monitoring process Methods 0.000 title claims abstract description 18
- 239000000446 fuel Substances 0.000 claims abstract description 14
- 238000005259 measurement Methods 0.000 claims description 22
- 238000012545 processing Methods 0.000 claims description 12
- 230000004044 response Effects 0.000 claims description 12
- 238000011156 evaluation Methods 0.000 claims description 10
- 230000000737 periodic effect Effects 0.000 claims description 10
- 230000001747 exhibiting effect Effects 0.000 claims 1
- 238000013016 damping Methods 0.000 abstract 1
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 239000002305 electric material Substances 0.000 description 1
- 230000003455 independent Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
- G01P3/42—Devices characterised by the use of electric or magnetic means
- G01P3/44—Devices characterised by the use of electric or magnetic means for measuring angular speed
- G01P3/48—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage
- G01P3/481—Devices characterised by the use of electric or magnetic means for measuring angular speed by measuring frequency of generated current or voltage of pulse signals
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/009—Electrical control of supply of combustible mixture or its constituents using means for generating position or synchronisation signals
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M65/00—Testing fuel-injection apparatus, e.g. testing injection timing ; Cleaning of fuel-injection apparatus
- F02M65/003—Measuring variation of fuel pressure in high pressure line
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
- G01L23/08—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically
- G01L23/10—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically by pressure-sensitive members of the piezoelectric type
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/08—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of piezoelectric devices, i.e. electric circuits therefor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
- F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
A monitoring system for a fuel- injection engine includes a pressure transducer having two pressure sensitive members (10) mounted on a support frame 20 which is slidably spring biassed towards a damping member 21 so as to urge the pressure sensitive members resiliently against an interposed fuel injection pipe of the engine. Electrical signals produced simultaneously by the pressure sensitive members or their positive/negative portions are combined to produce a resultant signal related solely to a characteristic of the engine. Peak valves may be compared with those from other injection pipes. e.g. to assess advance/retard. Alternatively the combined signals may be passed via a comparator to a counter timer for determining pulse periodicity. The comparator voltage is set to the average of the highest and lowest comparator voltages required to produce a regular pulse output, Fig. 4 (not shown). The converter timer circuit may include registers enabling short pulse trains to be analysed sequentially, and missing pulses in a train may be inserted. <IMAGE>
Description
SPECIFICATION -Monitoring system for a fuel-injection engine and a measurement circuit for use in the monitoring system
This invention relates to a system for monitoring an operating characteristic of a fuel-injection engine and it relates particularly, though not exclusively, to such a system for monitoring engine speed. The invention also relates to a measurement circuit for use in the monitoring system.
It is often desirable, when servicing an internal combustion engine, to monitor its speed.
Preferably this should be achieved with as little disturbance to the engine as possible. In the case of a diesel engine it is known to mount a pressure transducer on one of the fuel injection pipes so as to monitor a variation in a radial dimension of the pipe, due to changes of pressure which arise therein. In practice, however, the transducer output tends to be subject to interference, due to mechanical vibration in the pipe, and this can render an evaluation of engine speed both difficult and unreliable. It is, therefore, an object of the present invention to provide a monitoring system which at least alleviates this problem.
In accordance with a first aspect of the invention there is provided a system for monitoring an operating characteristic of a fuel injection engine, the system comprising a transducer including at least two pressure sensitive members and means to hold said pressure sensitive members against a fuel injection pipe of the engine; and a processing circuit for combining electrical signals produced simultaneously by said pressure sensitive members, in response to a variation of pressure in, and or vibration of, said pipe, to generate a resultant signal related to said characteristic.
The inventors have discovered that it is possible, using a monitoring system as defined, to generate a resultant signal which is relatively free from the effects of mechanical vibration and which can be utilised, with comparitive reliability, to monitor a desired characteristic. In an embodiment, the system comprises only two said pressure sensitive members which are held against the pipe in substantially opposed positions.
Respective faces of said pressure sensitive members may be inclined relatively to one another to define a wedge-like seating for the pipe, the holding means being arranged to apply a releasable clamping force to said members in a direction substantially bisecting the angle subtended by said inclined faces.
It will be appreciated that other configurations could be used. The pressure sensitive members could be clamped in diametrically opposed positions on the pipe so as to be substantially parallel to one another.
In an embodiment, said holding means may comprise a support member mounting said pressure sensitive members, a clamping member which, in use, bears on the pipe and spring biassing means acting between said support and clamping members to bias said pressure sensitive members resiliently against the pipe. With this arrangement it is possible to achieve a reasonably constant biassing force allowing the amplitudes of resultant signals, generated in respect of different injection pipes, to be compared.
The processing circuit may include a measurement circuit effective to evaluate the frequency of a periodic variation of the amplitude of said resultant signal, indicative of engine speed. The measurement circuit may comprise means for comparing the amplitude of said resultant signal with that of a threshold signal, means for controllably changing the amplitude of said threshold signal to search for, and maintain, a periodic pulse train at the output of the comparison means, and means to evaluate the periodicity of the pulse train. As the engine speed, and so periodicity, may not remain at a constant value it may be necessary to monitor the consistency of periodicity values obtained by analysing relatively small pulse batches.Thus, the evaluation means may be conditioned to operate on a number of different batches of pulses in said train and, in dependence on the respective periodicity values obtained, to operate on at least one further batch, constituted by at least two of said number of batches, to obtain a further periodicity value. The measurement circuit may also include means to measure the amplitudes of pulses in the resultant signal. It is possible, therefore, to compare the amplitudes derived in respect of different pipes in the same engine thereby to assess engine performance.
In accordance with another aspect of the present invention there is provided a measurement circuit, as defined hereinbefore, suitable for use in a monitoring system in accordance with said first aspect of the invention.
In accordance with a yet further aspect of the invention there is provided a pressure transducer suitable for monitoring an operating characteristic of a fuel injection engine, the transducer including a pressure sensitive device and means to releasably clamp said device against a fuel injection pipe of the engine, the clamping means being arranged to apply a predetermined and repeatable clamping force.
This arrangement permits the responses of different injection pipes to be compared reliably.
In an embodiment said pressure sensitive device comprises at least two pressure sensitive members mounted on a support member and said clamping means comprises a clamping member and means to resiliently bias the clamping member and the support member towards one another.
In an example, the inventors have found it advantageous to mount the pressure sensitive members so that their respective faces are inclined relatively to one another to define a wedge-like seating for the pipe, and the clamping means may be arranged to apply said clamping force in a direction substantially bisecting the-angle subtended by the inclined faces.
The resilient biassing means may comprise a spring, for example a coil spring, though alternative means such as an hydraulic piston could be used.
The transducer may form part of a monitoring system including a processing circuit for utilising an output of the transducer to generate a resultant signal related to said characteristic.
The processing circuit may include a measurement circuit of the kind defined by reference to said first aspect of the invention.
In order that the invention may be carried readily into effect an embodiment thereof is now described, by way of example only, by reference to the accompanying drawings of which,
Figure 1 illustrates the pressure variation in the fuel injection pipe of a diesel engine fitted with a rotary pump,
Figure 2 shows an arrangement of pressure sensitive members,
Figures 3a and 3b show respectively a perspective view of, and a cross-sectional view through, a pressure transducer having a releasable clamping member,
Figure 4 shows a measurement circuit for use in a monitoring system in accordance with the invention, and
Figure 5 shows a data store used in the measurement circuit.
Fig. 1 of the drawings iliustrates how the pressure varies in one of the fuel injection pipes of a four-cylinder diesel engine fitted with a rotary injection pump. Main pressure pulses Pm, of amplitude p, are generated periodically in the injection pipe whenever the associated cylinder is fired, and two (for a four cylinder engine) subsidiary pulses Ps(l) and Ps(2), of smaller amplitude (--p/3), are generated as a result of back pressure created in the pipe at succeeding stages in each firing sequence. In the case of an engine fitted with an in-line, rather than a rotary injection pump pressure pulses are generated periodically, as before, though the subsidiary pulses are absent.
The engine speed can be evaluated by measuring the periodicity of the main pressure pulses, and the inventors have discovered that this can be accomplished, with considerably improved reliability, using a transducer which has two pressure sensitive members held against one of the injection pipes, in substantially opposed positions, to monitor the pressure changes arising therein.
Fig. 2 shows two pressure sensitive members 10 which are held, in substantially opposed positions, against an injection pipe P by application of a clamping force represented generally at F. In this example, each pressure sensitive member comprises a film 11 of a piezo-electric material (e.g. pvdf) provided with suitable electrodes 13. The film is mounted on a support frame 20 and is fitted with a protective, metal anvil 12, the electrodes being insulated electrically from the frame and the anvil. If the pipe expands radially, due to a rise in pressure, both films 11 are compressed, and if, as shown, the films are poled in opposite senses i.e. one being poled inwardly, towards the pipe and the other outwardly, away from the pipe, then they will generate respective response signals which are of opposite polarity sign.If, on the other hand, the pipe contracts radially, due to a fall in pressure, the polarity signs of the two response signals will be reversed. In contrast, mechanical vibration of the pipe tends to enhance the pressure applied to one of the films and to relieve the pressure applied simultaneously to the other film and so those components of the two response signals which are due solely to mechanical vibration of the pipe will have the same polarity sign.
It will be appreciated that the response signals, produced simultaneously by the two pressure sensitive films can be suitably combined to generate a resultant signal which is substantially free from interference caused by mechanical vibration, the effects of which can be cancelled out. In this example, such a resultant signal is obtained by inverting one of the response signals and adding the inverted signal to the other response signal, though clearly alternative schemes may be devised depending on the relative poling senses of the films and or their mechanical configuration.
After suitable thresholding, the periodicity of pulses in the resultant signal, corresponding to the main pressure pulses generated in the monitored injection pipe, may be evaluated.
As shown in Fig. 2, the pressure sensitive members 10 are inclined slightly, relative to one another, to define a wedge-like seating for the pipe. This configuaration is beneficial in that it provides a relatively high mechanical advantage. Other configurations could, however, be used. For example, the pressure sensitive members could be clamped in diametrically opposed positions on the pipe so as to be substantially parallel to one another. The transducer shown in Figs. 3a and 3b comprises pressure sensitive members 10 mounted on a support frame 20 which can be displaced slidingly relative to a clamping member 21. The clamping member bears on the pipe and an internal spring 22 biasses the support and clamping members towards one another to urge members 10 against the pipe.
This arrangement provides a predetermined, and repeatable, clamping force, which is inde pendent of the user. The support member can be displaced, with respect to the clamping member, in opposition to the action of the spring, by any suitable user-operable means, and conveniently a Bowden cable, shown at 23, may be employed. This allows the transducer to be attached to, and detached from, a pipe with relative ease.
It will be appreciated that means other than spring 22 could be used to apply a clamping force to the pressure sensitive members. Alternatively, for example, a hydraulically operated piston could be used.
The resultant signal, produced by combining respective response signals generated by the pressure sensitive members 10, is processed in a measurement circuit shown in Fig. 4.
In order to identify pulses corresponding to the main pressure pulses, the resultant signal is initially subjected to thresholding in a comparator 30. The amplitude of the resultant signal is compared in the comparator with a controllably adjustable reference voltage VR generated at the output of a digital-to-analogue conversion circuit 31 under the control of a processing circuit 32 which is coupled to the output of the comparator via a monostable circuit 33.
Initially the reference voltage is set at a relatively high value which is reduced progressively, under the control of circuit 32, until at a value VA(A), say, the processing circuit senses that pulses are not only present at the output of the monostable circuit, and so the comparator, but have become substantially periodic. This value is stored in the processing circuit and the reference voltage is then reduced further until, at a smaller value VR(B), the periodicity of pulses ceases, indicating, in the case of an engine fitted with a rotary injection pump, that subsidiary pressure pulses are being detected, or that noise is being detected if this has a greater amplitude than the subsidiary pulses.The reference voltage is then set at a mean value V,(M)=1/2[V,(A)+ VR(B)] which, in this example, is deemed to be the optimium value consistent with detecting the main pressure pulses reliably. The mean reference voltage may be updated from time to time, though alternatively a system having three comparators could be used. The comparators would operate continuously, two of the comparators being used to evaluate respectively the reference values VR(A), VR(B) and the third comparator operating at-the mean reference value VR(M).
The periodicity of pulses generated at the output of the monostable circuit 33 is evaluated in a suitable counter/timing circuit 34.
Since, however, the engine speed may change from time to time it may be advantageous to evaluate the periodicity of relatively small batches of pulses and to compare the periodicity values obtained. Then, provided the periodicity values are reasonably consistent, a more precise evaluation can be made by operating on a larger batch made up from earlier, smaller batches.
To this end, the measurement circuit is provided with a data store 35 having two storage registers, designated I and II in Fig. 5, which are coupled operatively to the timing/counting circuit 34. Initially one batch, comprising 10 successively detected pulses, is clocked into the data store. Circuit 34 operates on the batch to evaluate the periodicity of the pulses and displays an appropriate value of engine speed whilst a further 10 pulses are being gathered in register I. Provided the periodicity values obtained are sufficiently consistent the pulses in register I are transferred to register II, to create a new batch of 20 pulses, 10 new pulses being clocked into register I.This procedure is then repeated until the batch in register II contains a sufficiently large number of pulses (e.g. 50), at which stage the oldest batch in register II is erased whenever a new batch is transferred thereto from register I. If, at any stage, the periodicity values are found to be inconsistent, suggesting that the engine speed has changed, the pulses contained in register II are erased and are replaced by the pulses in register I, which then receives a new batch of pulses. The procedure is repeated until consistent periodicity values are obtained.
Certain preliminary checks can be carried out on the pulses in register I before any periodicity evaluation is made. The periods between consecutive pulses in the batch may be measured to identify a period, common to at least six (say) pulses in the batch. If any period is twice the common period it is assumed that a pulse has not been detected and an additional pulse is inserted. Similarly if two consecutive periods, when added, equal the common period then a false period has been detected and this is removed.
If the common period occurs less than a designated number of times (eg. 6, say) then the pulse train is deemed unsuitable.
The resultant signal may be subject to inter ference, necessitating a change in signal processing e.g. by combining the response signals, produced by members 10, differently or by operating on the negative (or positive) part only of the resultant signal. If a common period is still not found it may be necessary to change the position of the pressure sensitive members on the pipe.
The measurement circuit may also comprise circuitry effective to measure the peak amplitudes of pulses in the resultant signal. With the arrangement described by reference to
Figs. 3a and 3b it is possible to achieve a substantially constant clamping pressure so that comparable amplitude measurements may be made in respect of different injection pipes in the same engine, thereby to assess engine performance (i.e. advance/retard).
Typically, the amplitude value measured in respect of one pipe may be stored and subsequent values expressed as a percentage of the stored value.
It will be understood that the measurement circuit of Fig. 4 may be used to process a response signal generated by alternative forms of transducer, of the kind, for example, which responds to each firing of a spark plug of a petrol engine.
Furthermore, although the system described by reference to the drawings, has two pressure sensitive members the invention also encompasses a system with one or more pressure sensitive members.
Claims (23)
1. A system for monitoring an operating characteristic of a fuel injection engine, the system comprising a transducer including at least two pressure sensitive members and means to hold said members against a fuel injection pipe of the engine, and a processing circuit for combining electrical signals produced similtaneously by said pressure sensitive members in response to a variation of pressure in, or vibration of, said pipe, thereby to generate a resultant signal related to said characteristic.
2. A system according to Claim 1 wherein there are only two said pressure sensitive members and said holding means is arranged to hold the pressure sensitive members in substantially opposed positions against the pipe.
3. A system according to Claim 2 wherein respective faces of said pressure sensitive members are inclined relative to one another to define a wedge-like seating for the pipe and said holding means is arranged to apply a releasable clamping force to the members along a direction substantially bisecting the angle subtended by said faces.
4. A system according to Claim 3 wherein said holding means comprises a support member mounting said pressure sensitive members, a clamping member which, in use, bears on the pipe and spring biassing means acting between said support and clamping members to bias said pressure sensitive members against the pipe.
5. A system according to any one of
Claims 1 to 4 wherein said processing circuit includes a measurement circuit effective to evaluate the frequency of a periodic variation of the amplitude of said resultant signal indicative of engine speed.
6. A system according to Claim 5 wherein said measurement circuit comprises means for comparing the amplitude of said resultant signal with that of a threshold signal, means for controllably changing the amplitude of said threshold signal to search for, and maintain, a periodic pulse train at the output of the comparison means, and means to evaluate the periodicity of said pulse train.
7. A system according to Claim 6 wherein said evaluation means is arranged to operate on a number of different batches of pulses in said train, and, in dependence on the periodicity values obtained, to operate on at least one further batch constituted by at least two of said number of different batches to obtain a further periodicity value.
8. A system according to Claim 7 wherein said evaluation means comprises first and second storage locations for storing successive batches of pulses, means to evaluate, and compare, the periodicity of pulses in said first and second storage locations and, in dependence on the comparison, to cause the pulses in said second storage location to be transferred to the first storage location to create said further batch.
9. A measurement circuit suitable for use in a system according to any one of claims 5 to 8, said circuit comprising means to compare the amplitude of an input signal, exhibiting a periodic variation indicative of engine speed, with'the amplitude of a reference signal, means for changing controllably the amplitude of said reference signal to obtain, at the output of said comparing means, a train of periodic pulses corresponding to said periodic variation indicative of engine speed, and means to evaluate the periodicity of said pulses.
10. A measurement circuit according to
Claim 9 wherein said evaluation means is arranged to operate on a number of different batches of pulses in the train and, in dependence on the periodicity values obtained, to operate on at least one further batch constituted by at least two of said number of differentbatches to obtain a further periodicity value.
11. A measurement circuit according to
Claim 10 wherein said evaluation means comprises first and second storage locations for storing successive batches of pulses, means to evaluate, and compare, the periodicity of pulses held in said first and second locations and, in dependence on the comparison, to cause the pulses held in the second storage location to be transferred to the first storage location to create a said further batch.
12. A system for monitoring an operating characteristic of a fuel injection engine substantially as hereinbefore described by reference to the accompanying drawings.
13. A measurement circuit substantially as hereinbefore described by reference to Figs. 4 and 5 of the accompanying drawings.
14. A pressure transducer suitable for monitoring an operating characteristic of a fuel injection engine, the transducer including a pressure sensitive device and means to releasably clamp said device against a fuel injection pipe of the engine, the clamping means being arranged to apply a predetermined and repea table clamping force.
15. A pressure transducer according to
Claim 14 wherein said pressure sensitive device comprises at least two pressure sensitive members mounted on a support member, and said clamping means comprises a clamping member and means to resiliently bias the clamping member and the support member towards one another.
16. A pressure transducer according to
Claim 15 wherein said pressure sensitive members have respective faces which are inclined relatively to one another to define a wedge-like seating for the pipe, and the clamping means may be arranged to apply said clamping force in a direction substantially bisecting the angle subtended by the inclined faces.
17. A pressure transducer according to any one of Claims 14 to 16 wherein said resilient biassing means comprises a spring.
18. A pressure transducer according to any one of Claims 14 to 16 wherein said resilient biassing means comprises an hydraulic piston.
19. A system for monitoring an operating characteristic of a fuel injection engine, the system including a pressure transducer according to any one of Claims 14 to 18 and a processing circuit for utilising an output of the transducer to generate a resultant signal related to said characteristic.
20. A system according to Claim 19 wherein said processing circuit comprises a measurement circuit effective to evaluate the frequency of a periodic variation of the amplitude of said resultant signal.
21. A system according to Claim 20 wherein said measurement circuit comprises means for comparing the amplitude of said resultant signal with that of a threshold signal, means for controllably changing the amplitude of said threshold signal to search for, and maintain, a periodic pulse train at the output of the comparison means, and means to evaluate the periodicity of said pulse train.
22. A system according to Claim 21 wherein said evaluation means is arranged to operate on a number of different batches of pulses in said train, and, in dependence on the periodicity values obtained, to operate on at least one further batch constituted by at least two of said number of different batches to obtain a further periodicity value.
23. A system according to Claim 22 wherein said evaluation means comprises first and second storage locations for storing successive batches of pulses, means to evaluate, and compare, the periodicity of pulses in said first and second storage locations and, in dependence on the comparison, to cause the pulses in said second storage location to be transferred to the first storage location to create said further batch.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB868602857A GB8602857D0 (en) | 1986-02-05 | 1986-02-05 | Monitoring system |
| GB868625276A GB8625276D0 (en) | 1986-02-05 | 1986-10-22 | Monitoring system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8701031D0 GB8701031D0 (en) | 1987-02-18 |
| GB2186089A true GB2186089A (en) | 1987-08-05 |
Family
ID=26290324
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08701031A Withdrawn GB2186089A (en) | 1986-02-05 | 1987-01-16 | Monitoring system for a fuel- injection engine |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2186089A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2675542A1 (en) * | 1991-04-16 | 1992-10-23 | Coton Jean | METHOD AND DEVICE FOR MEASURING THE PRESSURE OF FUEL INJECTED WITHIN THE INJECTION TUBES OF A DIESEL ENGINE. |
| FR2688890A1 (en) * | 1992-03-18 | 1993-09-24 | Coton Jean | METHOD FOR MEASURING ENGINE RPM OF INJECTION ENGINES AND DIESEL TACHOMETER IMPLEMENTING THIS PROCESS. |
| EP0727576A1 (en) * | 1995-02-20 | 1996-08-21 | Robert Bosch Gmbh | Process for detecting error conditions in diesel injection devices |
| CN102564679A (en) * | 2011-12-28 | 2012-07-11 | 芮国林 | Pipeline piezoelectric type pressure sensor |
| DE10242305B4 (en) * | 2002-09-12 | 2013-11-14 | Robert Bosch Gmbh | Method for measuring the speed of a pump motor |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3698248A (en) * | 1970-05-15 | 1972-10-17 | Bendix Corp | Pressure responsive transducer |
| GB1313935A (en) * | 1969-08-04 | 1973-04-18 | Bendix Corp | Pressure measuring transducer |
| GB1372030A (en) * | 1971-12-30 | 1974-10-30 | Cav Ltd | Transducers |
| GB1506701A (en) * | 1973-12-06 | 1978-04-12 | Scotus Marine Ltd | Pressure sensing device |
| GB2019581A (en) * | 1978-02-08 | 1979-10-31 | Scotus Patentverwalt | Pressure sensing apparatus |
| GB2138142A (en) * | 1983-04-12 | 1984-10-17 | Autosense Equipment Limited | A transducer for use in detecting the pressure of high pressure fuel in the injection supply pipe of a compression ignition engine |
-
1987
- 1987-01-16 GB GB08701031A patent/GB2186089A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1313935A (en) * | 1969-08-04 | 1973-04-18 | Bendix Corp | Pressure measuring transducer |
| US3698248A (en) * | 1970-05-15 | 1972-10-17 | Bendix Corp | Pressure responsive transducer |
| GB1372030A (en) * | 1971-12-30 | 1974-10-30 | Cav Ltd | Transducers |
| GB1506701A (en) * | 1973-12-06 | 1978-04-12 | Scotus Marine Ltd | Pressure sensing device |
| GB2019581A (en) * | 1978-02-08 | 1979-10-31 | Scotus Patentverwalt | Pressure sensing apparatus |
| GB2138142A (en) * | 1983-04-12 | 1984-10-17 | Autosense Equipment Limited | A transducer for use in detecting the pressure of high pressure fuel in the injection supply pipe of a compression ignition engine |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2675542A1 (en) * | 1991-04-16 | 1992-10-23 | Coton Jean | METHOD AND DEVICE FOR MEASURING THE PRESSURE OF FUEL INJECTED WITHIN THE INJECTION TUBES OF A DIESEL ENGINE. |
| WO1992018767A1 (en) * | 1991-04-16 | 1992-10-29 | Jean Coton | Method and device for measuring the pressure |
| FR2688890A1 (en) * | 1992-03-18 | 1993-09-24 | Coton Jean | METHOD FOR MEASURING ENGINE RPM OF INJECTION ENGINES AND DIESEL TACHOMETER IMPLEMENTING THIS PROCESS. |
| WO1993019375A1 (en) * | 1992-03-18 | 1993-09-30 | Jean Coton | Injection engine revolution measuring method and diesel tachometer therefor |
| EP0727576A1 (en) * | 1995-02-20 | 1996-08-21 | Robert Bosch Gmbh | Process for detecting error conditions in diesel injection devices |
| CN1061737C (en) * | 1995-02-20 | 2001-02-07 | 罗伯特-博希股份公司 | Method for detecting fault of diesel oil-jetting device |
| DE10242305B4 (en) * | 2002-09-12 | 2013-11-14 | Robert Bosch Gmbh | Method for measuring the speed of a pump motor |
| CN102564679A (en) * | 2011-12-28 | 2012-07-11 | 芮国林 | Pipeline piezoelectric type pressure sensor |
| CN102564679B (en) * | 2011-12-28 | 2014-03-19 | 芮国林 | Pipeline piezoelectric type pressure sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8701031D0 (en) | 1987-02-18 |
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