FIELD OF THE INVENTION
The invention generally relates to integrated display device for displaying error in
alternative fuel vehicles which is easy to understand, ergonomically good and
user friendly. More particularly, the invention relates to a system for detection
and communication of faults in fuel injection system of alternative fuel compliant
vehicles. The invention further relates to a method for detection and
communication of faults in a alternative fuel system of a vehicle.
BACKGROUND OF THE INVENTION
Automobiles are driven by internal combustion engines (ICE). For driving the
ICE, commonly used fuels are Gasoline, Diesel and CNG/LPG (or its variants).
With the introduction of new technologies, today's vehicles are becoming more
and more reliant on electronic components. Different systems of a vehicle that
are being developed and produced today are eqUipped with electronic systems
which enables the mechanical components to perform efficiently.
One such electronic device is used for the fuel injection systems for cars which
rely on electronic components to provide the engine an optimum amount of fuel.
In addition, the device is used for delivering optimum performance of the engine
while keeping the safety of the passengers and the vehicle.
With the rapid development of technology, the complexity of electronic systems
also increased and hence continuous monitoring and pre-emptive diagnosis of
operational health of the electronic devices is required more than ever to find out
about the possible system failure, and pre-warn the vehicle operator so that the vehicle could be taken to nearest service station for repairs before break-down or
meeting with accident.. A timely check-up allows the service engineer to
accurately diagnose the problem area and rectify the vehicle.
Moreover, alternative fuels like CNG& LPGare highly inflammable. These fuels
are stored at relatively higher pressure as compared to Gasoline or diesel, and a
minor malfunction in the fuel system could lead to a potential safety hazard.
Hence, a real-time diagnosis of system fault and simultaneous communication to
user is all the more essential.
The prior-art-diagnostic systems fails to ensure communication of the fault in a
convenient manner. Moreover, the communication methodology used in prior art
is confusing and the user may not be able to understand what remedial action
he/she has to take under specific circumstances.
The development in the field of automobile engineering, in particular the
alternative fuel compatible vehicles thus warrant:
1. A superior diagnostic system, with accuracy and better performance.
2. An automatic diagnosis system to detect the faults related to fuel injection
system in particular alternative fuel compliant vehicles.
3. Enabled to communicate the detected fault accuracy, simultaneously, and
easily-understandable.
OBJECTS OF INVENTION
It is therefore an object of the invention to propose a system for detection and
communication of faults in the fuel system of alternative fuel compatible
vehicles. Another object of the invention is to propose a system for detection and
communication of faults in the fuel system of alternative fuel compatible
vehicles, which enables immediate detection and communication of faults to the
user.
SUMMARY OF THE INVENTION
For the simplicity of the explanation, the following notations will be used:
1. Vehicle that can be driven by conventional fuels (Diesel/Gasoline): Type-A
2. Vehicles that can be driven by both conventional fuels (Type A) and
.alternative fuels (like CNG/LPG):Type B (Also, covers vehicles with small fuel
tank (Gasoline/Diesel) for limp-home purpose).
3. Vehicle that can be driven by alternate fuels (CNG/LPG)only: Type-C.
In Type-A vehicles, the engine is controlled by a single electronic control unit
(ECU). The ECUworks based on the signals transmitted from different sensors
(related to gasoline/diesel engines) for e.g. Coolant temperature sensor, Crank
sensor, Cam sensor etc. Basedon the pre-defined tuning, the ECUcomputes the
amount of fuel that is to be injected, and also controls the ignition timing of the
fuel.
In Type-B / Type-C vehicles, the fuel timing is additionally controlled by separate
sensors used for this system. The ECUmayor may not be the same as used for
Type-A systems.
The ECUs in all the above systems have an added functionality for system
diagnosis and is mainly driven by (original equipment manufacturer) OEMs
requirements. The diagnosis procedure is implemented in all the Type A, B & C systems. The system consists of provision of an ECU in such a manner that
defined inputs and outputs of the controller are monitored for any mal-function
(or fault). Once a fault is validated (through in-built diagnosis), the relevant error
code is stored inside the ECU.
Accordingly, there is provided a system for detection and communication of
faults in fuel injection device of alternative fuel compliant vehicles, comprising;
an engine rotatable by a starter motor and to generate an initial running speed
of the engine; an ignition switch on activation allOWingthe starter motor to
engage the engine; a plurality of actuators providing fuel to the engine via
dedicated fuel lines from a fuel tank; an electronic control unit (ECU) based on
input values and pre-stored values calculates and transmits signal in respect of
spark-timing, fuel quantity, and fuel injection timing which prOVidesthe engine
required speed so as to run without further input from the starter motor; a
communication line for transmitting signals from the ECUto a display deVice,
wherein the ECUis configured to conduct cyclic monitoring of peripheral deVices,
detect open circuit fault, short-circuit fault based on acquired and pre-stored
data and communicate to the vehicle operator the existence or otherwise of a
fault including type of the fault through displaying different indication pattern in
the display device.
BRIEF DEscRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - schematically shows a system for detection and communication of
faults in fuel systems of alternative fuel compliant vehicles according of
the invention.
Figure 2 - shows a generic flow-chart depicting a process for detection and
communication of faults in fuel systems of alternative fuel compliant vehicles according to the invention.
Figure 3 - shows a flow-chart illustrating cyclic health-monitoring of associated
peripheral devices of the engine system.
Figure 4 - shows an alternative embodiment of the process for detection and
communication of faults in fuel systems of alternative fuel compliant
vehicles
DETAIL DESCRIPTION OF THE INVENTION
As schematically shown in figure-1, during a normal start-up, to start the engine
[9], the operator firstly turns ON the Ignition switch [3] (hereafter referred to as
IGSW), and engage the starter motor [10] through IGSW (3) or the controller [1]
(hereafter referred to as ECU). The starter motor [10] then rotates the engine
(9) and brings it to an initial engine speed (hereafter referred to as RPM)which
is reqUired by the engine (9) to start automatically for firing. During this time,
the fuel is delivered to the engine (9) through a plurality of actuators [14] via
dedicated fuel lines [12]. The ECU, based on a plurality of sensors [5] values
and logics incorporated inside the ECU, provides the spark timing, and fuel
quantity and fuel injection timing. The fuel delivery is controlled by a Fuel control
valve [15] driven by the ECU.This allows the engine (9) to gain the required
RPMand thereafter it rotates without Starter motor's assistance.
Thus, the inventive system as shown in figure-1, comprises:
- an ECU (Electronic control unit (1)) and/or CNG ECU for driving cng
system (Optional); - a Speedometer or similar display device (2);
- an Ignition switch (3);
- a Fuel lid switch (4);
- a plurality of Sensors used for driving the engine (9) (including RPM,
Vehicle speed sensor);
- a CNGtank (6);
- a CNGreceptacle (7);
- a CNGfuel level/pressure sensor (8);
- an engine (9);
- a Starter motor (10);
- a Fuel Lid (11);
- a Fuel line (12)
- a Communication line (CANjSerialline) (13);
- a plurality of actuators (14) used for driving engine (inclUding controlling
of fuel delivery); and
- a fuel control valve (15) (for controlling the fuel delivery to engine).
In an implementation of this invention, the sensor values and internal ECU
circuits are constantly monitored by the ECU. There are several types of
diagnosisthat can be implemented in the system:
1. Open circuit fault detection
2. Short circuit fault detection
3. Plausibility check
Explanation for these and other types of faults & their healing mechanism that
are applicable for system diagnosis are beyond the scope of this application.
The process is implemented in a pre-defined manner as shown in Fig 2. The Type-B and Type-C fuel systems diagnosis is done in respect of:
1. The critical system fault in alternative fuel systems should be indicated to
user as soon as possible, enabling him to take corrective action and get
the system rectified.
2. The communication to user should be easy to understand and
ergonomically good.
The present invention is based on the exhaustive studies done with different user
patterns and behavior to cover all the above parameters. The implementation is
done by using a designated tell-tale, located in the speedometer/similar device to
communicate user about the possible malfunction in the system.
In vehicle operation, cyclic diagnostic checks are carried out by the engine
controller for health monitoring of the system peripherals. In this event the
sensor input values received are compared with a predefined safe limit of the
system. If the values lie outside the limits, it is considered as system error.
These system errors are stored in the ECUmemory. The status is again modified
after healing.
Once a fault is detected, the ECU decides as to how the same is to be
communicated to the user. For Type-B/C system, the same is done using the
designated tell-tale incorporated in vehicles speedometer (or similar devices).
After confirmation of the system error, the ECUdecides whether to turn ON the
indication or not depending on the type of error. After this decision, a r~quest is
sent to the speedometer or to a similar device to turn on the designated tell tale.
Based on the ECU's request (DISPLAY) the speedometer turns ON or OFF the
designated lamp/LED on the display device. The sequence of the process as depicted in figure-3, in as under:
Let PO: Peripheral device
POl means: Device#l
PD2 means: Device#2
PDn means: Device#n
Error in these devices is denoted as:
PD1ERROR
PD2ERROR
PDnERROR
Once the error is detected:
PDnERROR = TRUE
If the error is healed, the respective flag is set to FALSE
PDnERROR=FALSE
Let DISPLAY denotes the status of designated lamp on the display device:
if
PD1ERRORor PD2ERROR or ..... PDnERROR = TRUE,
DISPLAY=ON Or DISPLAY=BLINK
else
DISPLAY=OFF
Depending on error type, the lamp is set ON continuously or in a BLINKING
pattern.
In yet another embodiment, as shown in figure-4, for certain faults
(PDx1ERROR,PDx2ERRORsetc) are observed in the system, the ECUchanges
over from CNG/LPGmode to Gasoline/Diesel mode, and indicate the user by
blinking (DISPLAY=BLINK)the designated lamp/LED on the display device for a
defined time.
salient Points of Invention
1. Provision of indicating the fault to user through designated tell-tale(s) in
the speedometer or similar display unit.
2. The user will be indicated the presence of fault in the alternative fuel
system, enabling him to take action.
3. Based on the ergonomics study done for the position of the tell-tale was
finalised to be in speedometer or similar display device conveniently
visible to the user.
WE CLAIM
1. A system for detection and communication of faults in fuel injection device
of alternative fuel compliant vehicles, comprising:
- an engine rotatable by a starter motor and to generate an initial running
speed 0 the engine;
- an ignition switch on activation allowing the starter motor to engage the
engine;
- a plurality of actuators providing fuel to the engine via dedicated fuel lines
from a fuel tank;
- an electronic control unit (ECU) based on input values and pre-stored
values calculates and transmits signal in respect of spark-timing, fuel
quantity, and fuel injection timing which provides the engine required
speed so as to run without further input from the starter motor;
- a communication line for transmitting signals from the ECUto a display
device,
wherein the ECU is configured to conduct cyclic monitoring of peripheral
devices, detect open circuit fault, short-circuit fault based on acquired and
pre-stored data and communicate to the vehicle operator the existence or
otherwise of a fault including type of the fault through displaying different
indication pattern in the display device 2. The system as claimed in claim 1, wherein a plurality of sensors are
provided to acquire data relating to engine speed, vehicle speed, engine
temperature.
3. The system as claimed in claim 1, comprising at least one fuel
level/pressure sensor.
4. The system as claimed in claim 1, comprising a fuel control valve for
controlled delivery of fuel to the engine.
5. The system as claimed in any of the preceding claims, wherein the ECUis
configured to detect and communicate fault in specific devices of the fuel
system including fault in particular peripheral devices.
6. The system as claimed in any of the preceding claims, wherein the ECUis
enabled to automatically change-over the operating fuel mode of the
vehicle based on fault detection.
7. A system for detection and communication of faults in fuel injection device
of alternative fuel compliant vehicles as substantially described and
illustrated herein with reference to the accompanying drawings.