FIELD OF THE INVENTION
A device to assist proper locomotive operation during driving and like vehicles
and method thereof.
BACKGROUND OF THE INVENTION
It has been seen that there are many proposals in the past regarding the
upgrading of the engine speed control of Diesel Electric Locomotives from
mechanical to electrical/electronics to enhance internal combustion engine
efficiencies. In the diesel electric Locomotive the operator is required to change
the throttle also known as notches of the locomotive into eight discrete steps,
which results in the engine acceleration to the new speed levels. The crank shaft
of the diesel engine is coupled to a traction alternator which provides current to
the traction motors, as per the notch settings. The locomotive's control system
is designed in such a manner that its traction alternator’s electrical power output
is matched to any given engine speed and with respect to the innate
characteristics of traction motors, as well as the way in which the motors are
connected to the main generator. The traction alternator produces high current
and low voltage at low locomotive speeds and gradually changing to low current
and high voltage as the locomotive accelerates. The net power produced by the
locomotive, as per governor design remains constant for any given notch setting
to match the characteristics of the traction motors . The prime mover has
optimized RPM V/s horsepower characteristics at each notch where the fuel
efficiency is highest. This requires the prime mover to be run at this point as
closely as possible to avoid poor efficiency and to prevent build up of engine
deposits due to incomplete combustion. Thereby consequently resulting into
higher maintenance and running costs.
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The diesel electric locomotive while pulling heavy freight trains requires power to
be applied gradually, in order to minimize the risk of wheel slip and snapped
couplings. The diesel electric locomotives is provided with an ammeter to
indicate the driver the traction motor overload conditions arising from heavy
trains or prolonged operation at low speed on higher loads or gradients such
that the ampere reading are maintained within a tolerance limit. As the train
speeds up, more inertia is overcome, and more power can be applied. It can be
deduced from here that if the locomotives are notched incorrectly it would result
into fuel wastage as the optimum power of its prime mover remains
underutilized. It is also a known fact that the traction motors has varying
efficiencies for different voltage and current characteristics and therefore, if
notches are not operated properly these machines also tends to waste power.
The proper notching operation as required to be conducted by the driver of the
locomotive is a difficult task because of the various element in the locomotive
run, some of these elements being track gradients, wind loading, varying
conditions of track, varying train loads and also the driver is required to look out
for signals, speed restrictions, track intruders, train parting, hot axle etc.
US4118774, Locomotive speed control apparatus .This patent teaches a
method of measuring locomotive speed and then controlling its notches / throttle
automatically through contactors etc and other electronics. The automatic
system requires complex changes in the locomotive which are time consuming
and costs substantially and cannot be implemented on all designs of
locomotives. The system is too cumbersome on operating point of view, during
the time of rapid deceleration and acceleration of the locomotive or during the
time of emergency braking or other events such as shunting etc.
US5564657, Electronically controlled locomotive throttle controller including
remote multiple unit throttle control, Teaches a method to automatically
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controlled locomotives throttle. However such system requires major
modifications in the locomotive and also costs substantially and cannot be
implemented on all designs of locomotives. The system is too cumbersome on
operating point of view, during the time of rapid deceleration and acceleration of
the locomotive or during the time of emergency braking or other events such as
shunting etc.
The problem to be addressed is by interfacing a system which is capable of
identifying the driving operations conducted on the locomotive by monitoring
locomotive’s current consumed by its traction motors and an accelerometer to
check the locomotive’s acceleration and deceleration; thereafter the system
tracks the traction motor’s current for saturation with respect to deceleration rate
and computes the onset of traction motor’s power saturation condition. The
system immediately alarms the driver to advance the notch to next position such
that the locomotive doesn’t remain operating in low efficiency driving conditions.
Similarly, if the driver reduces the speed of the train the device tracks it and
alarms the driver to retreat the notches in efficient and controlled manner;
thereby resulting in saving fuel considerably.
The invention relates more particularly to a diesel electric locomotive but by not
way of limitations to such apparatus and method.
OBJECTS OF THE INVENTION
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It is the object of the invention to provide a device on the locomotive to identify
the driving pattern and ensure that the locomotive’s notch is applied in a timely
and efficiently manner, with respect to the varying loads. This is done by
measuring the current of its traction motors and the onset of its de-acceleration
as measured by the current sensor and its onboard accelerometer; thereby
timely and efficiently alerting the driver for the engagement/ disengagement of
the notch with respect to the desired speed set point or in general operating
procedures .The system is thus able to save on fuel and controls the locomotive
correctly by removing the human element.
It is another object of the invention to provide a device to measure the onset of
saturation in current consumption condition, of the locomotives traction motors.
It is another object of the invention to provide a device to measure the onset of
deceleration of the locomotive/ train with respect to its saturation in current
consumption condition, of its traction motors.
It is another object of the invention to provide a device to correlate the traction
motors current saturation with respect to the locomotives deceleration and
provide an audio visual alarm to the driver, for timely advancing or retreating of
the notch position.
It is yet another objective of the invention to allow driver to set a speed set point
and thereafter tracking its speedometer to alarm the driver for correct notch
operation to maintain the said speed.
It is yet another objective of the invention to measure locomotive speed from its
speedometer for correct notching operation to maintain a given speed.
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With the above and other objectives in view, as will hereinafter appear, various
embodiments of the present invention are described hereunder.
SUMMARY OF THE INVENTION
According to an embodiment of the invention, a device to assist proper
locomotive operation during driving, is provided, which comprises of a
microcomputer, interfaced to the traction motors through current transducers
appropriately, such that it could measure the current and hence compute the
onset of saturation in current consumption by its traction motors. The
microcomputer is further interfaced to an onboard accelerometer which is
monitored to identify the acceleration and deceleration of the locomotive / train.
The onset of saturation in current consumption by its traction motors is
compared with the onset of deceleration condition which provides an indication
for the onset of inefficient operating condition. The device hence provides an
audio visual alarm an audio visual alarm to the driver such that the notch is
advanced or retrieved in timely and efficient manner, to avoid operating the
locomotive in the said condition. The microcomputer is further interfaced to the
locomotives speedometer in order to measure the locomotive speed; and a
speed set-point unit for the driver, such that after a required speed is entered or
selected the microcomputer automatically issues alarms in timely and efficiently
manner to maintain the said speed point. The device is therefore able to alarm
driver in such a manner that the locomotive is operated efficiently, which
consequently results in saving fuel.
According to another embodiment of the invention, a current transducer is
interface to the locomotives traction motors to measure the onset of saturation in
their current consumption condition.
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According to another embodiment of the invention, an accelerometer is provided
to measure the onset of deceleration of the locomotive/ train with respect to its
saturation in traction motor’s current consumption condition.
According to yet another embodiment of the invention, to correlate the onset of
the traction motors current saturation condition with respect to the onset of the
locomotives deceleration condition and provides an audio visual alarm to the
driver, for timely advancing or retreating of the notch position.
According to yet another embodiment of the invention, a speed set-point unit
is provided to allow the driver to feed, select or adjust, a speed set point through
appropriate means and thereafter the system tracks onboard speedometer, to
alarm the driver for correct notch operation such that the said speed is
maintained with least effort.
According to yet another embodiment of the invention, the accelerometer and
the speedometer are analyzed to monitor and identify the driving activity for
acceleration, deceleration, braking, or constant speed operation and thereafter
the system alarms for the relevant notch operation efficiently.
Brief Description of the Drawings
Figure 1 shows a detailed view of various components of device according to an
embodiment of the present invention as interfaced to the diesel electric
locomotive.
For a better understanding of the embodiments of the invention and to show
how it may be performed, it will now be described in more detail with reference
to the accompanying drawings.
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Detailed Description of the Invention
The present invention can be better understood by reading the following detailed
description of some of the embodiments, with reference made to the
accompanying drawings. It will be understood that a particular system
embodying the invention is shown by way of illustration only and not as a
limitation of invention. The principles and features of this invention may be
employed in various numerous embodiments without departing from the scope
of the invention. References are made to accompanying drawing in which its
novel feature and advantages will be apparent.
As can be seen in Figure 1, it shows the various embodiments of the present
invention as interfaced to the Diesel Electric locomotive 1. The Locomotive’s
power output, and thus its speed, is typically controlled by the engine driver
using a throttle also known as notches of the locomotive distributed into eight
discrete steps. As the notches are advanced to the higher position or number it
results in higher engine acceleration and speed. The prime mover has optimized
RPM V/s horsepower characteristics at each notch where the fuel efficiency is
highest. This requires the prime mover to be run at this point as closely as
possible to avoid poor efficiency and to prevent build up of engine deposits due
to incomplete combustion. Thereby consequently resulting into higher
maintenance and running costs.
The present invention achieves this objective by measuring the
said condition through subsequent peaking and falling/ saturating of the traction
motor’s 4, current, through appropriately interfaced current sensor 5, to a
microcomputer 9. An accelerometer 6, is measured to identify the trains
acceleration or deceleration .The onset of traction motor’s 4, current saturating
condition is correlated with the onset of the locomotives deceleration to
compute the correct time for the advancement or retrieval to notch, which is
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alarmed to the driver through onboard audio visual display 7. The locomotive’s
speed requirement is further instructed to the microcomputer 9, through onboard
speed set point unit 10, which locks on to any operating speed by a press of a
button or the required speed could be appropriately entered through keys ,
potentiometer or stepped rotary switch . This speed set point unit 10, is thus able
to alarm the driver with correct and timely notching operation to maintain the
said speed through feedback obtained from its speedometer 8.
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I Claim:
1. A device to assist proper locomotive operation during driving,
comprising :
a microcomputer (9), interfaced to Locomotive (1), traction motors (4) ,
through current transducer (5), to measure the saturation in current of
the traction motor (4) at any given instant of time;
an accelerometer(6) interfaced with microcomputer(9) to further measure
the acceleration and deceleration produced by the locomotive/train; and
computes the onset of a saturation condition where the traction
motor’s(4) current reaches to a high level and then consecutively tends to
fall gradually, at any given instant of time to identify the power saturation
level of the motor; and
correlate the current pattern with acceleration and deceleration readings
as produced by the accelerometer (6); thereby
providing an alarm through audio visual display unit (7) at the time when
the current falls / deceleration is measured, to the driver such that the
notch is changed in timely and efficient manner.
2. The device as claimed in any of the preceding claims, wherein the
accelerometer(6) and the speedometer(8) are analyzed to monitor and
identify the driving activity for acceleration, deceleration, braking or
constant speed operation and thereafter the system alarms for the
relevant notch operation accordingly and efficiently.
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3. The device as claimed in any of the preceding claims, wherein the
traction motor’s subsequent acceleration and deceleration is measured
by interfacing a current sensor (5) by measuring the time it takes for the
current to reach at its subsequent peak and fall to measure the onset of
saturation in their current consumption condition.
4. The device as claimed in any of the preceding claims, wherein the
traction motor’s (5) permissible overload conditions are identified by
measuring its peak current and specified time limit of operation under the
said conditions, after duly accounting the make and characteristics of the
traction motors. Thereby providing an alarm to the driver for notch
retrieval to save the motors from damage.
5. The device as claimed in any of the preceding claims, wherein a speed
set point unit (10) is provided to the driver to enter the required speed
and it is tracked against the locomotive speed through its speedometer
(8) to alarm the driver for correct notch operation such that the said
speed is maintained with least effort.
6. The device as claimed in any of the preceding claims, wherein the speed
set point (10) can be achieved by entry through keys, potentiometer or
stepped rotary switch.
7. The device as claimed in any of the preceding claims, wherein an
Accelerometer(6) is provided to measure the onset of acceleration or
deceleration of the locomotive / train and correlate it with the traction
motor’s current saturation reading to calculate the inefficient operating
zone and alarms the driver for proper notch operation.
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8. The device as claimed in any of the preceding claims, wherein the onset
of the traction motors current saturation condition and the onset of the
locomotives deceleration condition are correlated to provide an audio
visual alarm to the driver, for timely advancing or retreating of the notch
position.
9. A device to assist proper locomotive operation during driving and like
vehicles and method thereof,substantially as herein described and
illustrated in the figure 1 of the accompanied drawings.