Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~`ield of the Invention
This invention relates to an instrument which records
a multiplicity of vehicle operating conditions. Such instruments
are generally known as tachographs.
Background of the Invention
Motor driven vehicles such as trucks, boats and the
like, are driver operated away from supervision. Such vehicles
are large energy users making them very costly to operate.
Control is required to assure safe as well as energy and
maintenance saving operation. Increasing complexity requires
that more and more functions be controlled. It is desirable to
continuously analogue record certain of the more critical
conditions. Others may be recorded in an on/off manner to
observe whether or not undesirable conditions exist.
Presently available recording instruments use a
plurality of styli for the recording of more than one variable.
However, because such instruments mounted in the vehicles must
be small, there is an obvious constraint of space and the
recording area on the charts is quite limited. This in turn,
limits the number of styli which can be used to record different
functions on the chart.
Another method used to increase the recording space
on a chart, is to record from both sides of the paper disc
forming the chart by means of opposed styli. Although this
arrangement overcomes the problem to a certain extent, it still
does not maximize the recording area available on the chart.
Present recording systems assign a stylus for each
parameter or operating condition to be recorded. Therefore the
number of variables which can be recorded is restricted due to
the very limited number of positions assignable to each stylus.
- 2 - ~
most present systems have a capacity of three styli on each
side of the paper disc.
The present invention maximizes the useable recordinq
area on a chart. It is based on controlling the stvlus such
than an individual stylus can record a multiplicitv of operating
conditions. The system preferably incorporates a single stylus
which is electronically controlled. It could however be mechani-
cally controlled and include more than one stylus.
The recording system o~ this invention therefore, is
for use in vehicles and records a multiplicity of operatinq con-
ditions on a chart. The system includes: the combination of
recording means which inscribes on the chart at essentially right
angles to the chart's direction of movement; servocontrolled
positioning means for positioning and moving the recording means
to a recording position in response to a control signal; and
control means to selectively direct different control signals for
the multiplicity of operating conditions to the servocontrolled
positioning means.
Brief Description of the Drawinqs
The above, as well as other advantages and features
of the present invention will become apparent in the followinq
detailed description of the preferred embodiments according
to this invention, wherein:
Figure l is a schematic view of the system showing a
plurality of alternative control means;
Figure 2 is a schematic of a control means used for
the automatic recording of vehicle oPerating conditions;
Figure 3 is a schematic of a recording system used
for the recording of independent simultaneously occurrinq vehicle
i~ operating conditions;
-- 3 --
1 Figures 4 through 9 are representative of charts onto
which various operating conditions have been recorded.
Detailed Description of the Preferred Embodiments
The following description relates to control signals
having different voltage levels in which ~ach voltage level
corresponds to a different operating condition. It is to be
understood that control signals or predetermined different
frequencies relating to the various operating conditions can
~lso be used to carry out the invention.
Figure 1 shows a recording system provided with stylus
guide 1 having a rack engaged-by gear 2, the position of which is
determined by motor 3. Motor 3, as shown in Figure 3, carries
a feedback mechanism providing a voltage output to line 4, which is
proportionate to the position of stylus guide 1. The internal
control of the motor automatically responds to a voltage input
through line 5, in such a manner that the feedback voltage along
line 4 is adjusted to the level of the input voltage. Therefore,
by applying appropriate voltages through line 5, one can select
the desired position of stylus guide 1. The stylus guide carries
stylus 6, which inscribes on chart 7. Chart 7 is held and rotated
by a conventional clock mechanism. (Not Shown)
The stylus and the guide carrying the stylus move at
essentially right angles to the direction of rotation of rotating
chart 7. The stylus provides the recording means, while the
motor with gear and stylus guide constitute the servocontrolled
positioning means. Through the use of control signals, the
recording means are controlled to assume a position corresponding
to the signal valve.
By suitable alternate selection from two or more
input signals, the recorder can now be made to record a variety
-- 4 --
1~'3;~2
of functions.
The analogue values of different parameters or operating
conditions can be consequtively scanned and recorded in a
predetermined pattern or in an irregular sequence as may be
required. As shown in Figure 6, the stylus records these para-
meters as lines or bands of different thicknesses with the upper
edge of the line or band representing the analogue value and
the width of the line or band indicating which parameter is
recorded.
Two parameters may be recorded starting from different
base lines as shown in Figure 8. On the other hand, one can use
a common base line by suppressing value ran~es normally not
occuring or not being of interest and record one condition in
the upper portion of the available total stylus travel and another
in the lower portion. By switching in short time intervals the
signal voltages for the servocontrolled driving means of the
stylus between those of the parameters the stylus moves in
short sequence between the points indicative for their value on
the chart.' As shown in Figure 9, this creates a solid band of
varying width. The upper borderline of the band showing the
values of one and the lower borderline the value of the other
parameter as an essentially continuous graph line.
The most simple type of multiple recording consists
in using an input system gererally indicated at A as shown in
Figure l. It consists of a control means comprising hand switch
8 with which line 9 can he connected alternatively to different
voltage levels available from a voltage divider 10 which is one
- form of a control signal generating means J By assigning for
instance different work situations of a vehicle driver like
waiting, loading and unloading to the different voltage levels,
-- 5
11~36;~2
;he occurrence of such work situations can be recorded on chart
7 by putting the hand switch in the corresponding position and
by moving switch 11 to a position where it connects line 5 with
line 9. Motor 3 will then move stylus 6 to positions corresponding
to the voltage level selected by hand switch 8.
An automatic recording of vehicle operating conditions
like engine operating parameters or conditions of auxillary
equipment on a vehicle can be made by using the input system B
shown in Figure 1. Engine operating systems are in many instances
presently equipped with pre-set limit switches which provide a
warning signal, i.e., a warning light or a buzzer, if crucial
parameters such as the coolant level, oil temperature, air pressure
etc., which are automatically sensed are in a critical condition.
In input system B these warning signals would be individually
connected to the control means comprising relays 12, 13, 14, etc.
These relays connect lines 15, 16, 17, etc. which take signals of
different voltage levels from the control signal generating
device 18 to a scanner 19. Scanner 19 continuously scans lines
15, 16, 17.
If for instance the coolant level drops below the
warning point the warning signal will activate relay 12 and
will therefore bring the voltage of line 15 into the scanner.
When the scanner finds this voltage it will stop for a pre-
determined period and transmit via the output line 20 the cor-
responding voltage to the motor 3 through switch 13 which has
been set to select the mode of control supplied by input system
B~ Oscillator 21 is provided in line 20. rrhis oscillator acts
as a control signal pattern generating means and superimposes
on the constant voltage supplied through line 15 ~rom the signal
~0 generating device 18 an oscillating voltage between zero and
-- 6
6~2
one Volt. Therefore, the recordin~ stylus 6 does not remain in
a steady position. It moves according to the voltage oscillation
and inscribes a narrow solid band on the chart as shown in the
left portion of Figure 4.
Another application of the invention is realized by
using the input system C shown in Figure 1. A variety of analoque
input signals as for instance rpm exhaust temperature, water
temperature, oil pressure are connected to signal conditioners
22 if the direct input signals are not compatible with the required
voltages on line 5. Each signal then passes through a control
signal pattern generating device such as oscillators Vl, V2,
V3 and V4 respectively. These control siqnal pattern qeneratinq
devices superimpose an oscillating voltage which is different for
each channel. Whenever one of the analogue channels is connected
by switching or control means 23 to line 24 and line 24 is connected
by selector switch 11 to line 5, then the corresponding analogue
signal with a superimposed identifying oscillating voltaqe is
recorded by stylus 6 on the chart. The chart recordings will
easily allow identification of the recorded signal by the width
of the inscribed band determined by the respective control signal
pattern generating device.
Figure 6 shows for instance three different parameters.
RPM of the engine are recorded as thin lines. The temperature
is recorded with a narrow band and the pressure is recorded by a
wide band.
Recordings obtainéd without the siqnal generating
device are shown in Figure 5. As can be seen, these different
parameters are only recognizable when they appear ort distinct
and separate locations on the chart. If these recordinq lines ~ot^
different parameters appear in the sa.~e portion of the charJ,
- 7
i3~
~here is an obvious interpretation problem. This is avoided
through the use of the control siqnal pattern generating device.
The applications described so far deal with situa-
tions in which the parameter to be recorded is selected by hand
or in which the conditions to be recorded are such that only one
of them can exist at anyone time. Should, however, conditions
occur simultaneously or in very short sequence of each other, a
special scanning system as shown in Figure 2 presents a refinement
of the invention. This scanning system can take the place of
scanner 19 in the case of parameters which may occur simultaneously.
The warning limit input channels Ia and Iu, which carry signals
from automatic limit switches, activate individual latches in
a latching device 25. A scanning device 26 scans these latches
continuously over scanning line 27 in a given sequence and
connects the warning signal of the channel concerned with the
output line 28 of the latch. Simultaneously, the scanning device
26 connects in the same scanning sequence, an individual pattern
created by the control signal pattern generating device 29 with
output iine 28 and output line 30. The scanning device controls
therefore, the warning input channel which is latched. The latch
signal is for a predetermined time transmitted through line 28
into the control signal pattern generating device where an
identifying signal pattern is superimposed on the signal. This
so modified and identified signal is sent through line 30 into
the servocontrolled positioning means which moves the record-
ing stvlus to a recording position.
When the control signal pattern generating device
29 receives an input through line 28, a timing device 31 is acti-
vated for a predetermined timing period. During this timing
~9 period, the timing device sends a signal along line 32 t:o the
114336;~2
scanning device, thereby stopping the scanninq device and
maintaining a connection between the latch and the control
signal pattern generating device through line 28. The timinq
device can be set to different time periods. These time periods
are selected such that the event which is recorded is clearly
recognizable on the chart. Therefore, to a certain extent,
the timing period is dependent upon the speed at which the chart
travels. At the end of the pre-set time period, the timing
device sends a release signal along line 33 to the latching
device thereby cutting off the signal along line 28 and a
re-start signal alon~ line 32 to the scanning device, which
continues its scanning until it again finds a latch in a latched
condition. The cycle then reoccurs.
After having scanned all the latches in the latchinq
device, the scanning device repeats its cycle of scanning. If
during the next cycle one of the channels is still in the warninq
mode, the warning signal reactivates the corresponding latch and
this warning signal is again recorded on the chart for a pre-
determined time period. If between scans the warning signal has
disappeared, then there is no repeat recording o the condition.
According to a preferred embodiment of this invention,
control signal pattern generating device 29 is eliminated and
each of the warnin~ limit switch event channels Ia and Iu is
provided with its own individual control signal pattern generating
devices such as those shown in in-put system C of Figure l, marked
Vl through V4.
Furthermore, the latching device can be set up such
that it will only react to a signal of a certain level o a
certain duration and signals below that level or duration are
~9 not latched in the latching device~ The latching device may be
_ g _
L replaced by other signal storage means or memories for the storin~
of the various signals relating to the warning conditions.
Fi~ure 4 shows a warning pattern as recorded by the
above-described system. The chart includes different radial
fields in which the warnin~ si~nals are recorded as a band. The
signal pattern carrying device may be designed to drop the voltage
to zero along line 30 when no warnin~ condition exists. Figure 4
shows this arrangement in which the stylus advances from zero to
radial field g for the recording of a condition. After record-
ing for the period of time set by the timing device, thestylus first returns to zero and then moves to radial field i :
for the recording of a second warning condition. Again the
stylus returns to zero and thereafter records in radial field
1. These recordings appear in the central portion of Figure 4.
The warning conditions recorded in radial fields
~, i, and e are not serious enough to require an immediate shut-
down of the vehicle. These warning signals are therefore trans-
mitted along lines Ia to the latching device.
Should the conditions become dangerous to the extent
that an immediate shut-down is required and a second warninq
signal from the same warning switch or a signal from a warning
switch at a different signal level, is sent to the latchinq
device along channels Iu, which carry information relatin~ to
shut-down conditions.
The control signal pattern generating device 29 may
identify the shut-down conditions in the same identifyinq
radial fields a-i of Figure 4. However they are identified in
a different manner. As is shown in the central portion of Fi~ure
4, the recording stylus has returned to the zero line at the
centre of the chart only for the first three events. The foul^th
-- 10 --
1~3~6~2
recorded warnill~ event, the secQ~ld one recorded in field g
shows the recording stylus moving to the outer edae of the chart
for all following warning recordings which relate to shut-down
conditions. Therefore, the three additional events shown in
fields i, g and e occurred as shut-down conditions in which
case the initial warning condition had deteriorated to a shut-
down condition. This recordin~ pattern can be effected by
selecting a signal pattern for shut down conditions in which
the stylus will receive a full voltage at the beginning and the
end of each recordin~ period determined by the timing device 31.
In another application of the invention it is possible
to record two parameters in an analoque fashion. Two different
possibilities of recording are shown in Figure 7 and Figure 8.
These recordings are obtained by adapting switchin~
means 23 such that it automatically switches line 24 in a
pre-set time pattern between the various input channels. In
this case the signal conditioners 22 function in the following
manner. In order to obtain the recording pattern as shown in
Figure 7 in which a common base line 50 is used the signal
conditioner for the rpm channel provides a volta~e to line 24
which brings the stylus into the zero position. ~7ith increases
of the rpm the voltage increases and reaches a maximum at a
location above the base line. Therefore, whenever line 24 is
connected to V4 generating a control signal pattern relating to
rpm, the stylus assumes the position between base line 50 and
locations above the base line which correspond to the rpm of
the motor.
In order to operate from the common base line the
signal conditioners for both rpm and exhaust temperature provide
identical voltages when both conditions are at zero. ~s the
input signals are transmitted to the servocontrolled positioning
means the stylus moves above and below the common base 'ine
depending upon which condition is being recorded. If both
conditions remain at zero the stylus will record along the zero
line.
Figure 8 shows a modified recording pattern for
recording rpm which is recorded in the upper radial fields with
base line 52 and temperature which is recorded in the lower
radial fields having a base line 54. As can be seen the low
rpm ranqes are suppressed so that recordings start only with
1000 rpm. Temperatures under 900 are also suppressed. Further-
more, temperature as well as rpm scales are arranged such that
both are rising from the inside to the outside of the chart.
The voltages for engine rpm are processed such that
anything up to 1000 rpm provides a constant voltage. Increases
in rpm above 1000 rpm increase the signal voltages such that
recordings above base line 52 are obtained on the chart.
Correspondingly the exhaust temperature voltages are
processed such that no voltage is supplied to motor 3 when the
temperature is below 900 degrees. However, between 900 and
1600 degrees a corresponding voltage increase will make the
stylus record between the base line 54 and base line 52. This
recording system allows therefore a convenient relatively larqe
scale simultaneous recording of two vehicle parameters.
In addition to the recording of varying conditions,
the control of vehicle conditions requires the recording of
cumulative figures or the counting of events and units. This
is done conventionally by recording a saw toothed pattern. The
recording stylus in such a pattern is made to move between
fixed top and ~ottom positions. The mechanical or electrical
- 12 -
~ 6~2
1 movin~ means are desiqned in such a fashion that for eac}l unit
to be eounted the stylus is made to move from the bottom upwards
by a certain small inerement. The number of increments or steps
required to move the stylus from the bottom position to the top
position is usually made equal to the number of steps required
to brin~ the stylus from the top position back to the bottom
position. In tachoqraph charts it is, for instance, common to
make the stylus travel from the bottom to the top and the top
to the bottom eclual to a distance of 5 miles travelled. If the
number of units to be counted remains constant per unit of time,
the resultin~ recording looks like a saw-tooth pattern. Whenever
time passes without adding any additional units the up and
down lines become horizontal lines if recorded on a tape or
seetions of a cirele if reeorded on eircular charts.
A modified applieation of this invention eonsists in
eontrollincJ the stylus in a eorrespondin~ way by electrical
means to reeord or count quantities. Aqain this system can be
applied in a more advaneed fashion to not only eount one but
two different kind of units with one stylus. An example of such
2~ reeordings is shown in.Fi~ure 9 .
The radial fields above base line 56 constitute the
recordin~ area for siqnals relating to a first quantity, i.e.,
packin~ cycles of a garbage collection truck. The radial fields
between base lines 56 and 58 constitute the recordin~ area for
information relatincJ to a second quantity, i.e., the number of
~allons of fuel consumed by the ~ehie].e.
To record the number of units of 2 different quantities
it is necessary that a pulse sendinc3 unit is provided for each
of the quantities to be controlled. The number o~ packaqinq
cycles can, for instance, be controlled by a limit switch actuated
- 13 -
1 duLing each cycle of the mechanical packer, so that for each cycle
one pulse is available. The number of gallons consumed by the
engine can be metered by a fuel meter equipped with a pulse
sending unit sending pulses for every one tenth of a gallon.
Such fuel meters are commonly used and available.
The ori~inal pulses of these sending units are then
modified by a pulse shaping unit, so that the resultinq pulses
are of constant amplitude and duration. These pulses are then
accumulated in a ramp providing an output voltage which increases
in equal increments with each pulse. After reaching a maximum
voltage corresponding to the number of pulses which results in
the upward travel of the stylus, the function of the ramp is
reversed and the output voltage is reduced Per pulse by the
same increment or drops in one step to the minimum voltaqe.
Therefore, the ramp converts the continuous pulses in a cor-
responding risin~ and falling output volta~e. These risinq and
fallin~ output voltages of each channel are then alternatively
and in a short period cycle connected to the input line 5 for
motor 3. This automatic cyclinq between the two voltaqes results
in the recording pattern as shown in Figure 9 . This system
also allows the mixing of recording patterns as shown in
Figures 4 throu~h 9 by one instrument on the same chart. It
would, for instance, be easy to have the entire recordinq pattern
as shown in Figures 8 and 9, recorded in the upper radial fields
and have fuel consumption recorded in the lower radial fields.
Another possible application would be to record the
number of passengers in a bus at any ~iven moment in the upper
part of the chart and to continuously record the number of passen-
gers entering the bus in the lower part of the chart. The
bottom fields would then be a quantity recordinq line while the
- 14 -
6~`2
1 top fields would represent the condition figure for any given
moment.
In certain cases it may be an advantaae to record a
multitude of events and even simultaneously occuring events
at essentially the moment that they occur. Figure 3 shows a
system adapted to carry out this type of recordinq. The
functions of stylus guide 1, gear 2, motor 3, line 5 and feedback
line 4 and chart 7 are identical to those described with
respect to Figure 1. However, this system contains a modification
of stylus 6 which enables the stylus to be lifted throuqh
solenoid 34 from the chart surface. Solenoid 34 is controlled
by relay 35 which is normally closed and lifts the stylus from
the chart, so that no recordings occur. In broad terms solenoid
34 and relay 35 function as deactivating means for the recording
stylus.
~ arning limit switches (not shown) provide inputs
along lines 60 through 64 to individual voltage range controlled
relays 36 through 40. The voltage range controlled relays contain
internal controls causing them to close only within the determined
voltage limits. These predetermined voltage limits are selected
to correspond to the stylus position feedback voltage supplied
throush line 4 such that the oil pressure relay 40 closes when the
stylus is in the recordi~g range for oil pressure, that the oil
level relay 39 closes when the stylus is in the recording range
for oil level, etc. The result of this calibration is that
during the travel of the recording stylus from its inward position
to its outer position the relays close whenever the stylus is
within that respective recording range. The stylus 6 is made
to perform an automatic regular travel from the top position to
) the bottom position by the stylus position control voltaqe genera-
- 15 -
32
1 tor 41. The speed with which this control voltage generator
supplies from zero to the maximum voltage determines the speed
with which the stylus 6 travels in and out with respect to the
chart.
If, for instance, an oil level warning signal should
be present then this signal will be transmitted through the oil
level relay when stylus 6 is in the oil level range of recordinq.
Relay 35 is then activated through line 42 to open the normally
closed relay. Whenever relay 35 opens the stylus is pressed
against the chart by a built-in spring. ~en the stylus leaves
the oil level recording range the feedback voltage through line 4
either drops below or exceeds the voltage range, openinq the oil
level relay. This closes relay 35 so that the stylus is retracted
to a non-recording position.
This invention which is based on the use of a
signal stylus for recording a plurality of operating conditions
offers the following advantages.
1. It permits a large number of on/off operating
conditions ie. twenty to thirty depending on the width of
the radial fields to be recorded in an easily identified
manner on instruments of conventional size.
2. Existing instrument designs can be modified
and used to obtain this versatile multicondition recording
pattern.
3. Through the use of the present system a quick,
easy to scan chart is obtained and by selecting all measurable
parameters of engine and vehicle operation which are either
unsafe, undesirable or technically damaging from an
operational point of view, the malfunctions in the motorized
3Q vehicle can easily be detected.
- 16 -
1 4. A malfunction assignment of recording analosues
values through the use of a single stylus is achieved
by (a) selecting and manually switching from condition to
condition ~b) adapting the system such that the recording
automatically switches to an operating condition exceeding
a preset danger level and (c) simultaneously analogue recording
two operating conditions by recording their values on
either side of a common base line. The latter mentioned
proposal also has the ramnification that in the case of
a diesel engine operation RPM can be recorded on one side
of the base line and heat recorded on the opposing side
of the base line. The total distance between the RPM and
heat recording line is an indicator of the total power level
produced by the engine from which is determined the wear
on the engine.
Although various preferred embodiments of the
invention have been described herein in detail, it will be
apparent to one skilled in the art that variations may be
made thereto without departing from the spirit of the
invention or the scope of the appended claims.
- 17 -
