Method for producing trigger pulses in relation to preset phase of motion proceeding with continuously variable period and device for effecting same

A method for producing trigger pulses in relation to a preset phase of motion proceeding with a continuously variable period, whereby pulses are accumulated, and at the same time two time intervals are successively determined within the fundamental time interval as the phase of the motion is changed by a preset value. The durations of these two time intervals and the sign of the difference between them are used to correct the number of stored pulses which are counted until a preset number is reached, which moment marks the onset of a trigger pulse. The device for effecting this method comprises a unit for determining the difference between time intervals and correcting the fundamental time interval, which is connected to a control unit, a main pulse counter and a main controlled frequency divider connected, in turn, to a pulse generator. The control unit is connected to a control pulse unit and an initial adjustment unit.

FIELD OF THE INVENTION 
The present invention relates to automotive engineering and, more 
particularly, to methods and devices for producing trigger pulses in 
relation to a preset phase of motion proceeding with a continuously 
variable period. 
The method and device of this invention are readily applicable to fuel 
injection and ignition timing in internal combination engines. 
BACKGROUND OF THE INVENTION 
The No 1 characteristic of the automotive market today is the demand for 
reliable and economical vehicles. Health authorities the world over are 
imposing strict limitations on the toxicity of exhaust gases. These 
factors account for stringent requirements imposed on individual units and 
systems of vehicles, including the ignition and fuel injection systems. 
However, it is impossible to produce better vehicles only by improving the 
existing mechanical ignition distributors and fuel injection systems. The 
solution to the problem seems to be the use of electronic trigger pulse 
systems. 
There is known a method for producing trigger pulses in relation to a 
preset phase of motion proceeding with a constantly variable period (cf. 
U.S. Patent No. 3,934,563), whereby a first control pulse is formed as a 
preset phase of the motion is reached, a second control pulse is formed as 
the phase of the motion is changed by a preset value which corresponds to 
a fundamental time interval, and pulses are accumulated, whereof the 
repetition frequency is at least one order greater than that of the 
control pulses, whereupon the accumulated pulses are counted until a 
preset number is reached, which moment marks the onset of a trigger pulse. 
There is known a device for producing trigger pulses in relation to a 
preset phase of motion proceeding with a constantly variable period. The 
device is intended to carry out the foregoing method and comprises a 
control unit having its inputs connected to an initial adjustment pulse 
unit and a control pulse unit, whereas outputs of the control unit are 
connected to a main pulse counter and a main controlled frequency divider, 
respectively, which are interconnected. The main pulse counter has its 
output connected to a comparator. The main controlled frequency divider 
has its input connected to a pulse generator. The device further includes 
an auxiliary controlled frequency divider having its first input connected 
to the pulse generator, its second input connected to a load sensor, and 
its output connected to an auxiliary pulse counter whose output is 
connected to the comparator. 
The aforesaid method and device have certain disadvantages. Between the 
start of integration of electric pulses and the instant a trigger pulse is 
produced, the phase of the motion changes considerably, for example, by 
80.degree.; the acceleration of the periodic motion may be so high as to 
lead to an inevitable dynamic error in producing a trigger pulse. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a method for producing 
trigger pulses in relation to a preset phase of motion proceeding with a 
continuously variable period, which would rule out a dynamic error in 
producing a trigger pulse. 
It is another object of the invention to provide a device for producing 
trigger pulses in relation to a preset phase of motion proceeding with a 
continuously variable period, incorporating an auxiliary unit aimed at 
eliminating a dynamic error in producing a trigger pulse. 
The first of the foregoing objects is attained by providing a method for 
producing trigger pulses in relation to a preset phase of motion 
proceeding with a continuously variable period, whereby a first control 
pulse is formed upon reaching a preset phase of the motion, a second 
control pulse is formed as the phase of the motion changes by a preset 
value corresponding to a fundamental time interval, and pulses are 
accumulated during the fundamental time interval, whereof the repetition 
frequency is at least one order greater than that of the control pulses, 
which accumulated pulses are counted until reaching a preset number, which 
moment marks the onset of a trigger pulse, the method being characterized, 
according to the invention, in that a first time interval and a second 
time interval are successively determined within the fundamental time 
interval as the phase of the motion changes by the preset value, each of 
the first and second time intervals corresponding to a change of the phase 
of the motion by such a value that the total change in the phase of the 
motion is equal to the change of the phase of the motion by the preset 
value, which is followed by determining the difference between the first 
and second time intervals at the end of the fundamental time interval and 
using the sign of this difference to correct the duration of the 
fundamental time interval. 
The second object of the present invention is attained by providing a 
device for producing trigger pulses in relation to a preset phase of 
motion proceeding with a continuously variable period, intended for 
carrying out the above method and comprising a control unit having its 
inputs connected to an initial adjustment pulse unit and a control pulse 
unit, respectively, and its outputs connected to a main pulse counter and 
a main controlled frequency divider, respectively, which are 
interconnected, the main pulse counter having its output connected to a 
comparator, whereas the main controlled frequency divider has its input 
connected to a pulse generator, the device further including an auxiliary 
controlled frequency divider having its first input connected to the pulse 
generator, its second input connected to a load sensor and its output 
connected to an auxiliary pulse counter whose output is connected to the 
comparator, the device also including a unit for determining the 
difference between time intervals and correcting the fundamental time 
interval, having its first input connected to the main controlled 
frequency divider, its second and third inputs connected to the outputs of 
the control unit, and its outputs connected to the main pulse counter. 
According to the invention, the correction of the fundamental time interval 
is effected in such a way that the dynamic error in producing a trigger 
pulse is negligible. Thus the invention can be used to advantage in all 
cases where great accelerations are encountered.

DETAILED DESCRIPTION OF THE INVENTION 
According to the invention, the method for producing trigger pulses in 
relation to a preset phase of motion proceeding with a continuously 
variable period is carried out as follows. A first control pulse is formed 
upon reaching a preset phase of the motion. A second control pulse is 
formed as the phase of the motion changes by a preset value corresponding 
to a fundamental time interval. A first time interval and a second time 
interval are then successively determined within the fundamental time 
interval as the phase of the motion changes by the preset value. Each of 
the first and second time intervals corresponds to a change in the phase 
of the motion by such a value that the total change of the phase of the 
motion is equal to the change of the phase of the motion by the preset 
value. The difference between the first and second time intervals is 
determined, and pulses are accumulated during the fundamental time 
interval. The repetition frequency of the pulses is at least one order 
greater than that of the control pulses. The duration and sign of the 
difference between the first and second time intervals are used to correct 
the number of accumulated pulses at the end of the fundamental time 
interval, whereupon the accumulated pulses are counted until a preset 
number is reached, which moment marks the onset of a trigger pulse. 
A preferred embodiment of a device for carrying out the method for 
producing trigger pulses in relation to a preset phase of motion 
proceeding with a continuously variable period, in accordance with the 
invention is hereinafter described by way of example, and is intended to 
produce ignition pulses in carburetor engines. 
According to the invention, the device for producing trigger pulses in 
relation to a preset phase of motion proceeding with a continuously 
variable period comprises a control unit 1 (FIG. 1), whereof inputs 2 and 
3 are connected to a control pulse unit 4 and an initial adjustment pulse 
unit 5, respectively. A first output 6 of the control unit 1 is connected 
to an input 8 of a main pulse counter 7. The output 6 is also connected to 
an input 10 of a unit 9 for determining the difference between time 
intervals and correcting the fundamental time interval. A second output 11 
of the control unit 1 is connected to an input 12 of the unit 9; it is 
also connected to an input 14 of a main controlled frequency divider 13. 
Outputs of the unit 9 are connected to respective inputs 15 and 16 of the 
counter 7. One more input 17 and one more output 18 of the counter 7 are 
connected to an output 19 and an input 20, respectively, of the frequency 
divider 13. The other output 21 of the frequency divider 13 is connected 
to an input 22 of the unit 9. An input 23 of the frequency divider 13 is 
connected to a pulse generator 24 having its output connected to an input 
25 of an auxiliary controlled frequency divider 26. An input 27 of the 
auxiliary controlled frequency divider 26 is connected to a load sensor 
28. The divider 26 has its output connected to an auxiliary pulse counter 
29 whose output is connected to an input 31 of a comparator 30. A second 
input 32 of the comparator 30 is connected to an output 33 of the pulse 
counter 7. An output 34 of the comparator 30 serves as the output of the 
device. 
The units 4 and 5 are mounted on a stationary part of an internal 
combustion engine, such as the flywheel cover (not shown), in immediate 
proximity to a part which rotates synchronously with the engine shaft, 
such as a flywheel 35 (FIG. 2) with marks 36, 37 and 38 corresponding to 
phases of motion. 
The spacing between the marks 36 and 37 corresponds to a change 
.DELTA..phi..sub.1 of the phase of motion; the spacing between the marks 
37 and 38 is .DELTA..phi..sub.2, and that between the marks 36 and 38 is 
.DELTA..phi.. 
The unit 9 for determining the difference between time intervals and 
correcting the fundamental time interval incorporates a flip-flop 39 (FIG. 
3) whose output is connected to a control input 41 of a reversible counter 
40. A counting input 42 of the counter 40 is connected to a coincidence 
gate 43. A first output of the counter 40 is connected to an input 45 of a 
flip-flop 44; two more outputs of the counter 40 are connected to inputs 
47 and 48, respectively, of a switch 46. The flip-flop 44 has its output 
connected to a control input 49 of the switch 46; said output of the 
flip-flop 44 is the output 16 of the unit 9. The output of the switch 46 
is the output 15 of the unit 9. A control input 50 of the flip-flop 39 and 
an input 51 of the coincidence gate 43 are combined into the input 10 of 
the unit 9. A counting input 52 of the flip-flop 39 and an input 53 of the 
flip-flop 44 are combined into the input 12 of the unit 9. A second input 
of the coincidence gate 43 is the input 22 of the unit 9. 
The device for producing trigger pulses in relation to a preset phase of 
motion proceeding with a continuously variable period, in accordance with 
the invention, operates as follows. 
From the output of the initial adjustment pulse unit 5 (FIG. 1), pulses are 
applied to the input 3 of the control unit 1, whereby the latter is set in 
the initial state. In response to the marks 36, 37 and 38 (FIG. 2) on the 
flywheel 35, the control unit 4 forms respective control pulses 54, 55 and 
56 represented in FIG. 4a. 
The spacing between the marks 36 and 38 (FIG. 2) corresponds to a change of 
the phase of the motion by a preset value .DELTA..phi.. According to the 
invention, the mark 37 is interposed between the marks 36 and 38 so that 
the control pulse 55 (FIG. 4a), formed in response to said mark 37, 
divides the fundamental time interval .DELTA.T shown in FIG. 4b into 
intervals .DELTA.T.sub.1 and .DELTA.T.sub.2 (FIG. 4a) which correspond to 
changes of the phase of the motion by values .DELTA..phi..sub.1 and 
.DELTA..phi..sub.2 (FIG. 2), respectively, where .DELTA..phi..sub.1 
+.DELTA..phi..sub.2 =.DELTA..phi.. From the output of the unit 4, control 
pulses are applied to the input 2 (FIG. 1) of the control unit 1 which 
forms a pulse 57 represented in FIG. 4b. The duration of the pulse 57 is 
equal to .DELTA.T. 
From the output 6 (FIG. 1) of the control unit 1, the pulse 57 (FIG. 4b) is 
applied to the input 8 (FIG. 1) of the main pulse counter 7. During the 
time interval .DELTA.T (FIG. 4b), the counter 7 stores pulses applied to 
its input 17 (FIG. 1) from the output 19 of the main controlled frequency 
divider 13. In the course of a process 58 (FIG. 4c) of accumulating pulses 
during the time interval .DELTA.T (FIG. 4b), the number of stored pulses 
reaches N (FIG. 4c). After the time interval .DELTA.T (FIG. 4b), the unit 
9 (FIG. 1) for determining the difference between time intervals and 
correcting the fundamental time interval corrects, through the inputs 15 
and 16 (FIG. 1) of the counter 7, the number N (FIG. 4c) of pulses stored 
over the time interval .DELTA.T (FIG. 4b), which is done with due regard 
for the value and sign of the acceleration, found from the difference 
between .DELTA.T.sub.1 and .DELTA.T.sub.2 (FIG. 4a). As a result, the 
number of pulses becomes N.sub.1 (FIG. 4c). 
The correction being over, an instruction is sent from the output 18 of the 
counter 7 (FIG. 1) to the input 20 of the divider 13, whereby pulses are 
passed from the output 19 of the divider 13 to the input 17 of the counter 
7, which carry out a process 59 (FIG. 4c) of counting the pulses stored by 
the counter 7 (FIG. 1). The process 59 (FIG. 4c) continues until the 
number of pulses stored by the counter 7 (FIG. 1) is equal to N.sub.2 
(FIG. 4c) which is the number of pulses stored by the auxiliary counter 
29. N.sub.2 is determined by a signal arriving from the load sensor 28 via 
the auxiliary controlled frequency divider 26. 
The instant t.sub.1 (FIG. 4c), when the number of pulses stored by the 
counter 7 (FIG. 1) is equal to N.sub.2 (FIG. 4c), i.e. the number of 
pulses stored by the counter 29 (FIG. 1), is determined by the comparator 
30, its input 32 receiving information from the output 33 of the counter 
7, whereas its input 31 receives information from the output of the 
counter 29. 
The unit 9 (FIG. 1) for determining the difference between time intervals 
and correcting the fundamental time interval operates as follows. 
From the output 11 (FIG. 1) of the control unit 1, the control pulses 54, 
55 and 56 (FIG. 4a) are applied to the counting input 52 (FIG. 3) of the 
flip-flop 39. The first control pulse 54 (FIG. 4a) resets the flip-flop 39 
(FIG. 3). As this takes place, a signal is applied from the flip-flop 39 
to the input 41 of the reversible counter 40, whereby the latter starts 
adding up pulses applied to its input 42 from the output of the 
coincidence gate 43. The gate 43 is driven into conduction for the time 
interval .DELTA.T (FIG. 4b) by the pulse 57 applied to its input 51 (FIG. 
3) from the output 6 (FIG. 1) of the control unit 1. 
Upon the arrival of the control pulse 55 (FIG. 4a), which signifies the end 
of the time interval .DELTA.T.sub.1 (FIG. 4b), the flip-flop 39 (FIG. 3) 
is set and makes the counter 40 subtract pulses. Upon the end of the pulse 
57 (FIG. 4b), the gate 43 (FIG. 3) is cut off, and the counting of pulses 
is discontinued. The remainder of the pulses stored by the counter 40 is 
indicative of the difference between the time intervals .DELTA.T.sub.1 and 
.DELTA.T.sub.2 and, consequently, of the degree of acceleration. The sign 
of the acceleration is determined by the flip-flop 44 whose input 45 
receives a signal of the zero state of the counter 40. The flip-flop 44 is 
reset by the control pulses 54, 55 and 56 (FIG. 4a) applied to its input 
53 from the output 11 (FIG. 1) of the control unit 1. 
From the output of the flip-flop 44 (FIG. 3), a signal is applied to the 
control input 49 of the switch 46, whereby a signal is passed to the input 
15 of the counter 7 (FIG. 1) either from the output 47 (FIG. 3) or from 
the output 48 of the counter 40, depending on the sign of the 
acceleration. 
A signal from the flip-flop 44 is also applied to the input 16 (FIG. 1) of 
the counter 7, whereby a certain number of pulses is either added to or 
subtracted from N (FIG. 4c). The number of these pulses corresponds to the 
difference between .DELTA.T.sub.1 and .DELTA.T.sub.2 (FIG. 4a); these 
pulses are applied to the input 15 (FIG. 1) of the counter 7 from the 
output of the switch 46 (FIG. 3). 
The present invention provides for a more accurate timing of trigger 
pulses, which, in turn, accounts for a higher output of an internal 
combustion engine under dynamic conditions.