U.S. patent application number 15/518426 was filed with the patent office on 2017-11-02 for device for controlling at least one switchable valve.
The applicant listed for this patent is Robert Bosch GmbH. Invention is credited to Wolfgang Fischer, Haris Hamedovic, Stephan Jahn, Bastian Reineke, Andreas Rupp, Christian Steinbrecher.
Application Number | 20170314494 15/518426 |
Document ID | / |
Family ID | 55638198 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170314494 |
Kind Code |
A1 |
Rupp; Andreas ; et
al. |
November 2, 2017 |
DEVICE FOR CONTROLLING AT LEAST ONE SWITCHABLE VALVE
Abstract
A method for controlling at least one switchable valve, a brake
impulse that slows down the valve movement being produced during
the controlling of the at least one valve, the position and/or the
length of the brake impulse being specified as a function of a
switching time of the valve, it being checked whether a
characteristic feature occurs that indicates the switching time,
and, upon occurrence of the characteristic feature, the position
and/or the length of the brake impulse being adapted based on the
position of the characteristic feature.
Inventors: |
Rupp; Andreas; (Marbach,
DE) ; Reineke; Bastian; (Schwieberdingen, DE)
; Steinbrecher; Christian; (Boeblingen, DE) ;
Hamedovic; Haris; (Moeglingen, DE) ; Jahn;
Stephan; (Stuttgart, DE) ; Fischer; Wolfgang;
(Gerlingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robert Bosch GmbH |
Stuttgart |
|
DE |
|
|
Family ID: |
55638198 |
Appl. No.: |
15/518426 |
Filed: |
September 24, 2015 |
PCT Filed: |
September 24, 2015 |
PCT NO: |
PCT/EP2015/071979 |
371 Date: |
April 11, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02D 41/26 20130101;
F02D 2041/2058 20130101; F02D 41/34 20130101; F02D 2200/0606
20130101; F02D 41/2438 20130101; F02D 2041/2037 20130101; F02D
41/20 20130101; G05B 15/02 20130101; F02D 2200/0406 20130101; F02D
41/2467 20130101; F02D 2041/2055 20130101; F02D 2200/0602 20130101;
F02D 2200/0618 20130101; F02M 61/10 20130101; F02D 2200/021
20130101 |
International
Class: |
F02D 41/24 20060101
F02D041/24; G05B 15/02 20060101 G05B015/02; F02D 41/26 20060101
F02D041/26; F02D 41/24 20060101 F02D041/24 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 21, 2014 |
DE |
10 2014 221 273.1 |
Sep 18, 2015 |
DE |
10 2015 217 955.9 |
Claims
1-12. (canceled)
13. A method for controlling at least one switchable valve, the
method comprising: producing, during controlling of the valve, a
brake impulse that slows down a valve movement of the valve, at
least one of a position of the brake impulse, and a length of the
brake impulse, being specified as a function of a flight behavior
of the valve; and checking whether a characteristic feature occurs
that characterizes the flight behavior, and, upon occurrence of the
characteristic feature, the position and/or the length of the brake
impulse is adapted based on the position of the characteristic
feature.
14. The method as recited in claim 13, wherein at least one of a
corrected position of the brake impulse, and a corrected length of
the brake impulse, is ascertained based on the characteristic
feature.
15. The method as recited in claim 13, wherein the at least one of
the position of the brake impulse, and the length of the brake
impulse, are specified as a function of further characteristic
quantities, the further characteristic quantities including at
least one of a temperature, a pressure, and a voltage.
16. The method as recited in claim 13, wherein the characteristic
feature indicates a switching time.
17. The method as recited in claim 16, wherein the characteristic
feature is a bend in a voltage curve or in a current curve,
recognized on the basis of a first derivative of the voltage curve
or of the current curve.
18. The method as recited in claim 16, wherein the switching time
is recognized based on a second derivative of a voltage curve.
19. The method as recited in claim 13, wherein the characteristic
feature is a beginning of a flight phase of a valve needle.
20. The method as recited in claim 19, wherein the beginning of the
flight phase is recognized from a first derivative of a current
curve.
21. A machine-readable storage medium on which is stored a computer
program for controlling at least one switchable valve, the computer
program, when executed by a controller, causing the controller to
perform: producing, during controlling of the valve, a brake
impulse that slows down a valve movement of the valve, at least one
of a position of the brake impulse, and a length of the brake
impulse, being specified as a function of a flight behavior of the
valve; and checking whether a characteristic feature occurs that
characterizes the flight behavior, and, upon occurrence of the
characteristic feature, the position and/or the length of the brake
impulse is adapted based on the position of the characteristic
feature.
22. A control device designed to control at least one switchable
valve, the control device designed to: produce, during controlling
of the valve, a brake impulse that slows down a valve movement of
the valve, at least one of a position of the brake impulse, and a
length of the brake impulse, being specified as a function of a
flight behavior of the valve; and check whether a characteristic
feature occurs that characterizes the flight behavior, and, upon
occurrence of the characteristic feature, the position and/or the
length of the brake impulse is adapted based on the position of the
characteristic feature.
Description
BACKGROUND INFORMATION
[0001] German Patent Application No. DE 10 2009 000 132 A1
describes a method for controlling at least one switchable valve.
There, in the controlling of the at least one valve a brake impulse
is produced that slows down the valve movement. The position and/or
the length of the brake impulse are specified as a function of a
switching time of the valve. The effect on the switching noise here
is essentially a function of the position and the duration of the
brake impulse.
[0002] If the brake impulse does not take place at the right time
and with the right duration, it does not deploy its full
effectiveness. In the extreme case, it has no effect. Based on
changing conditions and/or aging effects at the valve, the time
changes at which the switching time occurs. With this the time also
changes at which the brake impulse deploys its full
effectiveness.
SUMMARY
[0003] An method according to the present invention may have the
advantage that the noise effect is maintained even as boundary
conditions change, such as the voltage at the valve, the fuel
pressure, and the temperature.
[0004] This may be advantageously achieved in accordance with the
present invention by checking whether a characteristic feature
occurs that indicates for example the flight characteristic of the
valve needle, and when the characteristic feature occurs, the
position and/or the length of the brake impulse is adapted on the
basis of the position of the characteristic feature.
[0005] It is particularly advantageous if, based on the
characteristic feature, a corrected position and/or length of the
brake impulse is ascertained.
[0006] In an improved specific embodiment, the position and/or the
length of the brake impulse is specified as a function of further
characteristic quantities, such as the temperature, the pressure,
and/or the voltage. In this way, a more precise specification of
the brake impulse is possible.
[0007] It is particularly advantageous if a switching time is used
as characteristic feature. At the switching time, the valve needle
reaches its impact. Ideally, the brake impulse is triggered shortly
before reaching the switching time.
[0008] The characteristic feature can be ascertained particularly
simply if the characteristic feature is a bend in the voltage curve
or in the current curve, recognized on the basis of the first
derivative of the voltage curve or current curve.
[0009] It is particularly advantageous if the switching time is
recognized based on the second derivative of the voltage curve.
[0010] In a particularly advantageous specific embodiment, the
characteristic feature is the beginning of a flight phase of the
valve needle. The beginning of the flight phase is situated before
the position of the brake impulse and is therefore not influenced
by it. Therefore, this characteristic feature can also be
ascertained when a controlling with brake impulse takes place.
[0011] Further advantageous embodiments are described herein.
[0012] It is particularly advantageous that the beginning of the
flight phase is recognized from the first derivative of the current
curve.
[0013] In a further aspect, the present invention relates to
program code together with processing instructions for creating a
computer program that can be executed on a control device, in
particular source code having compiler and/or linking instructions,
the program code resulting in the computer program for executing
all steps of one of the described methods when it is converted into
an executable computer program according to the processing
instructions, i.e., in particular is compiled and/or linked. This
program code can be given in particular by source code, which can
be downloaded for example from a server in the Internet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Exemplary embodiments of the present invention are shown in
the figures and are explained in more detail below.
[0015] FIG. 1 shows the main elements of a device for controlling a
valve.
[0016] FIG. 2 shows various signals plotted over time.
[0017] FIGS. 3 through 6 show current curves and/or voltage curves
of various specific embodiments.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0018] In FIG. 1, a device is shown for controlling a valve 100. In
the depicted specific embodiment, valve 100 is connected in series
with a switch 110 and a measurement device 120, between the two
terminals 130 and 135 of a power supply. A control device 140
supplies switch 110 with a control signal A. Measurement device 120
supplies control device 140 with a measurement quantity. In
addition, sensors 150 are provided that forward sensor signals to
control device 140.
[0019] The sequence and the number of elements connected in series
are shown only as examples. Measurement device 120, switch 110, and
valve 100 can also be configured in a different sequence. In
addition, it can be provided that a further switch or other circuit
elements are provided.
[0020] Control device 140 calculates, based on various sensor
signals and further quantities present in the control device, a
control signal A to be supplied to switch 110. A current flows
through valve 100 as a function of the position of switch 110. As a
function of the current, a voltage drop arises at the valve.
Current measurement device 120 measures in particular the current
flowing through valve 100. Alternatively, it can also be provided
that the voltage drop at valve 100 is acquired using a suitable
measurement device 120.
[0021] When the valve is opened or closed due to being supplied
with current, switching noises occur. These switching noises can be
significantly reduced by interrupting the controlling during
switching on or by a brief re-switching on after switching off. The
effect on the switching noise here is a function of the time and
the duration of these two so-called brake impulses.
[0022] In FIG. 2a, control signal A is plotted over time t. In FIG.
2b, the stroke H of the valve is plotted, and in FIG. 2c the
current I flowing through the valve is plotted. At time t0, the
controlling of the valve begins. Starting from this time, control
signal A is present at switch 110. Current I through the valve
increases with time. At a time t1, control signal A is interrupted,
and is switched on again at time t2. This has the consequence that
the current drops off between times t1 and t2. This time t1 is
chosen such that between times t1 and t2 the valve needle moves in
the direction of its new position. At time t3, control signal A is
withdrawn in order to end the injection. Starting from time t3, the
current decreases and the valve needle moves slowly back to its
initial position. At time t4, switch 110 is again controlled, this
controlling ending at time t5; i.e., the flow of current is
switched on again between times t4 and t5.
[0023] The first time duration, between times t0 and t1, in which
current is supplied to the valve is designated ITO. The second time
duration, in which current is supplied to the valve between times
t2 and t3, is designated IT1. The third time duration in which
current is supplied to the valves, between times t4 and t5, is
designated IT2. In the first pause time P0 between times t1 and t2,
the valve is switched off. In the second pause time P1 between
times t3 and t4, the valve is also switched off.
[0024] In FIG. 3 current curve I is plotted over time t. The
switch-on process is shown with the beginning of the supply of
current. At time t0, the controlling of the flow of current through
the valve thus begins. First, the current increases. As soon as the
valve needle begins to move, the inductance of the valve changes
and the current flow deviates from its previous curve. In the
depicted specific embodiment, it is even the case that the current
briefly decreases. When the valve needle reaches its stop, the
current increase again changes. This happens at time ts. The
interval between the beginning of the supply of current at time t0
and this switching time ts is designated opening delay tan. The
specific current curve during the opening process differs from
magnetic valve to magnetic valve. However, in all magnetic valves
there occurs a characteristic feature that indicates the switching
time. In the specific embodiment depicted in FIG. 3, the
characteristic feature is the bend in the current curve at time ts.
In most valves, the current curve has a bend or a similar feature
at the switching time. A corresponding feature also occurs at the
termination of the controlling. The time duration between the
termination of the controlling of the closing of the valve is
designated closing delay tab. Here, a corresponding feature can be
determined from the curve of the induction voltage of the
valve.
[0025] Alternatively, the switch-off time can be made visible in
the current signal through a suitable circuit. For this purpose,
the valve must be supplied with current during the closing time
without resulting in a new lifting of the valve needle.
[0026] Opening delay tan and closing delay tab of the valve are
preferably determined without brake impulse. The opening delay is
defined as the time duration from the beginning of the controlling
up to the impact of the armature on the inner pole. Here,
preferably the characteristic change in the increase in the current
is used as the characteristic feature. Closing delay tab is defined
from the end of the controlling without brake impulse up to the
impact of the needle on the valve seat. It is preferably determined
by evaluating the induction voltage during switching off. Here, the
change in the increase in the voltage signal is used as the
characteristic feature.
[0027] The brake impulse during switching on is determined by the
parameters position and duration. The position of the brake impulse
during switching on corresponds to time t1. This is determined
through the time duration ITO after the beginning of the
controlling at time t0. The duration of the brake impulse during
switching on corresponds to time duration P0 between times t1 and
t2.
[0028] These two parameters are preferably determined based on the
characteristic feature and, possibly, further characteristic
quantities. As the characteristic feature, time ts, or a quantity
derived from this time, such as opening delay tan, is used.
[0029] This determination preferably takes place in the control
device based on the measurement quantities of measurement value
ascertaining 120, based on which opening delay tan is ascertained,
and based on the sensor signals of sensors 150. As further
characteristic quantities, preferably the voltage, the fuel
pressure, the intake manifold pressure, and the temperature are
used. As voltage, preferably the supply voltage present between
terminals 130 and 135 is used. As pressure, preferably the pressure
difference between the fuel pressure and the intake manifold
pressure is used. As temperature, various temperature values, such
as ambient temperature, engine temperature, or fuel temperature can
be used. It would be particularly advantageous to use the valve
temperature, which can be ascertained either by a sensor or through
a suitable model. Through the use of these characteristic
quantities in the specification of the position and the length of
the brake impulse, there results a substantial reduction in noise
emissions.
[0030] Preferably, the parameters that determine the brake impulse
are stored in one or more characteristic maps, as a function of the
characteristic feature and, possibly, the further measurement
quantities and/or characteristic quantities.
[0031] According to the present invention, it has been recognized
that boundary conditions change. For example, opening delay tan
changes during operation of the internal combustion engine, or over
time due to age-related defects or changing environmental
influences. This has the result that the brake impulse no longer
occurs at the optimal time.
[0032] Therefore, according to the present invention it is provided
that opening delay tan is newly ascertained. Standardly, during
operation with brake impulse opening delay tan cannot be
ascertained immediately, because the switching time in the control
phase occurs during time period P0. This has the result that the
characteristic current curve cannot be recognized, and therefore
cannot be evaluated.
[0033] In the extreme case, the changing boundary conditions can
have the result that opening delay tan becomes smaller. This can
have the result that the characteristic feature in the current
occurs already before time t1, i.e., during the phase ITO. In this
case, time duration ITO is correspondingly reduced. If changing
boundary conditions have the result that opening delay tan becomes
larger, then the characteristic feature in the current can occur
after time t2. In this case, time duration ITO will correspondingly
increase. In these two extreme cases, opening delay tan can be
recognized and correspondingly taken into account despite the brake
impulse.
[0034] FIG. 4 shows the derivative of the current DI plotted over
time t. At the beginning, the derivative of the current, which
corresponds to the change in the current, has an almost constant
value. At time tm, the derivative of the current reaches a maximum,
and then falls off. This falling off of the increase is caused by
the needle movement. Subsequently, the change again climbs steeply.
At the beginning of the falling off of the climb, the flight phase
of the needle begins. According to the present invention, a
characteristic feature is ascertained that characterizes the
beginning of the flight phase. For this purpose, the value dIM of
the rise in the current is ascertained. The time tf, at which the
rise has fallen off by the value ddl, is used as the beginning of
the flight phase of the valve needle. This time tf is used as the
characteristic feature instead of time ts. Here, this quantity tf
can be used directly as the characteristic feature. Alternatively,
the interval taf between time t0 and tf can be used instead of the
quantity tan.
[0035] The use of the beginning of the flight phase tf is
particularly advantageous because this time is before the beginning
of the brake impulse and is therefore not influenced by it. In this
way, this characteristic feature can supply information about the
flight behavior of the valve needle even in braked operation.
Therefore, this feature is particularly well-suited for
parameterizing the brake impulse.
[0036] In FIG. 5a, the current curve at time t0 is plotted over
time, and in FIG. 5 the corresponding voltage curve is plotted over
time. Voltage U decreases slowly starting from time t0. At time ts,
voltage U has a small maximum. Based on this maximum, switching
time ts can be ascertained. For this purpose, the voltage is
filtered so that disturbing quantities contained in the voltage
signal are minimized. By evaluating the derivative of the voltage
signal, time ts is ascertained at which the voltage has a local
maximum.
[0037] In an alternative embodiment, it can also be provided that
given a recognized wrong positioning of the brake impulse, a new
measurement of opening delay tan is carried out by switching off
the brake impulse and ascertaining the characteristic feature.
[0038] This means that, based on the measured characteristic
feature, a corrected position and/or length of the brake impulse is
ascertained.
[0039] According to the present invention, when the valve is
switched off a brake impulse is also specified. The brake impulse
during the switching off is defined by the position and by the
duration. The position of the brake impulse during the switching
off is defined by time t4, which is defined by the time duration P1
since the end of the controlling at time t3. The duration of the
brake impulse at the switching off corresponds to time duration IT2
between times t4 and t5.
[0040] The two parameters P1 and IT2, or the position and the
duration of the brake impulse, are also set as a function of the
closing delay tab as well as further boundary conditions such as
voltage, temperature, and pressure. Here as well, the closing delay
tab is newly calculated from time to time, similar to the case of
the opening delay. The procedure at the brake impulse during
switching off is analogous to the procedure for the specification
of the brake impulse during switching off. The only difference is
that during switching off, closing delay tab is used instead of
opening delay tan.
[0041] FIG. 6 shows the current curves and voltage curves of a
corresponding specific embodiment. At time t4, the brake impulse
begins with a rise in the voltage. At the same time, the current
increases. At time ts, the valve needle reaches its closed
position. This time ts is designated switching time ts, analogous
to the specific embodiment according to FIG. 3. The interval
between time t4 and time t2 is designated closing delay tab.
Closing delay tab is used for the ascertaining of the parameters of
the brake impulse during closing, in a manner analogous to the use
of the opening delay for the ascertaining of the parameters of the
brake impulse during opening of the valve.
[0042] Preferably, time t2 is obtained by evaluating the first or
second derivative of the current curve. In particular, time ts is
recognized at the time at which the first derivative with respect
to time of the current curve has a local minimum.
* * * * *