EP2545269A2

EP2545269A2 - Motor control device for actuating a circuit and method

Info

Publication number: EP2545269A2
Application number: EP11705184A
Authority: EP
Inventors: Uwe Surges; Lars-Daniel Rinze
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-03-09
Filing date: 2011-02-09
Publication date: 2013-01-16
Also published as: JP2013521437A; JP5506958B2; KR20130038225A; DE102010002678A1; US20130057065A1; WO2011110397A2; CN102782305A; US9353717B2; WO2011110397A3; CN102782305B

Abstract

The present invention relates to a motor control device for actuating a circuit, in particular a starter in a vehicle. The motor control device comprises at least one first means (31) for providing a first signal (1), in particular an ignition signal, a second means (30) for providing a voltage (2) for the circuit, a third means (32) for connecting the circuit, a first switch (5a), which is arranged between second and third means for controlling the circuit, and a fourth means (13, 14) for generating a second signal, wherein the first signal (Ia) cooperates with the second signal (Ia) to form a virtual second switch for switching the circuit on or off by means of the first switch (5a).

Description

description

title

Engine control unit for driving a circuit and method of the prior art

The present invention relates to an engine control unit for driving a circuit, in particular a starter in a vehicle. Engine control units are used in automotive technology and serve there to control engine components, such as a starter of the engine or a fuel pump. Inputs and outputs can be connected to the engine control unit corresponding engine components for their control. For example, the battery voltage is applied via a first input of the engine control unit, a signal can be provided via a second input, for example an ignition signal which then actuates corresponding switches within the engine control unit so that the starter or the fuel pump can ultimately be energized and Engine is then started by switching on the starter and the fuel pump.

The switches are usually either one-sided connected to the positive pole of the battery voltage and switch to a corresponding signal of the microcontroller, a starter relay, etc. to ground. Such switches are known as so-called. Highside switch. However, there is also the reverse case, in which a so-called Lowside switch, the starter relay or the fuel

Pump relay connects to the negative pole of the battery voltage.

In order to detect errors in the circuits during operation of a vehicle, such as short circuits of the starter to minus or ground, are from DE 196 165 43 C1 or DE 44 02 1 15 A1 corresponding devices with special circuits or engine control units have become known, which allow error detection of short circuits.

In addition, it has become known to provide both a highside and a low side switch to increase the safety against faults, especially short circuits when starting vehicles. The operation is as follows. In the engine control unit, a high-side switch is provided which is connected on the one hand to the battery voltage, on the other hand to a first output of the engine control unit. The control of the highside switch takes place via a microcontroller of the engine control unit. By doing

Engine control unit is further provided a low-side switch, which is connected to an output of the engine control unit, wherein the output is connected to ground, and to a second input. Between the first output and the second input of the engine control unit there is connected a relay for the starter, which only energizes the circuit of the starter when both high side and low side switches are switched on, i. are conductive. In the event of a short circuit of a single switch, the circuit of the starter is not energized, which increases the safety, as an uncontrolled starting starter or a fuel pump is undesirable.

However, there is a trend to minimize the weight of cables, etc. in order to minimize the weight of the vehicle as a whole. In practice, therefore, often either the high side or the low side switch is shorted. This saves weight, since additional cables for connecting the relay to the second input of the engine control unit can be dispensed with.

In the case of short circuit of the highside switch, the relay of the starter is thus directly connected to the battery voltage, in the case of short circuit of the low side switch, the relay of the starter is connected directly to ground. Although this saves cable and weight, it increases the likelihood of an uncontrolled switch-on of the starter since only one relay with a switch opens or closes the circuit of the starter. Advantages of the invention

The defined in claim 1 engine control unit for driving a circuit, in particular a starter in a vehicle and the corresponding method according to claim 10 have the advantage that the security against unwanted switching of the circuit is increased by short circuit and at the same time the number of necessary connections is further reduced, which reduces the total costs for the same security significantly. Likewise, the probability of a wrong connection of the circuit is reduced, since only one output for the respective circuit is available.

The features listed in the dependent claims relate to advantageous developments and improvements of the subject matter of the invention.

According to a preferred embodiment of the invention, the first and second means comprises an input of the engine control unit and the third means an output of the engine control unit. The advantage here is that in a simple and inexpensive way, the engine control unit can be integrated into circuits of vehicles and the signals can then be provided.

According to a further preferred development, at least one third switch is arranged between the first switch and an output of the engine control unit for controlling a second electric circuit, in particular for a fuel pump. The advantage here is that not only a circuit, in particular the circuit for the starter via the engine control unit can be switched, but also other circuits, such as a fuel pump, sensors for monitoring, ignition coils, etc .. Thus, the number necessary engine control units are reduced to a minimum, the same applies to the number of cables, etc. for driving the circuits. Likewise, the maintenance or replacement of the engine control unit is simplified, since in case of damage or malfunction, the entire engine control unit can be easily replaced. According to a further preferred development, the engine control unit comprises a device, in particular a microcontroller, for controlling at least the third switch. The advantage here is that the device can not only be used for the control of the third switch, but the device can also serve to monitor circuits that are connected to the engine control unit, serve.

According to a further preferred development, the engine control unit comprises at least one device for detecting errors. The advantage here is that both errors within the engine control unit can be detected, as well as errors in the circuits connected to the outputs of the engine control unit, such as the starter, sensors, etc. The means for detecting errors first detects these errors and, as far as a distinction of the various errors is not possible, checks on the basis of further tests, for example by opening and closing different circuits and / or by applying different voltages within a small time window, which errors are present in detail. The errors are then stored in a fault memory, so that they can then be read out, for example, by connecting an external diagnostic tool. It is also possible that the documented error is signaled on a display device for a driver of a vehicle, so that he can visit a repair shop and fix the error.

According to a further preferred development, the at least one device for detecting errors comprises at least one analog-to-digital converter.

The advantage here is that in a simple way the respective status of the monitored switch or circuit can be tapped. By specifying corresponding tolerance threshold values, the device can then analyze various analog levels by means of the analog-to-digital converters, for example by means of a software running on them, and detect and document the respective status of the circuit to be monitored.

According to a further preferred development, the fourth means comprises a low-side power amplifier, in particular a starter power amplifier module, for example an R2S2. The advantage here is that the use of a particularly specially designed low-side power amplifier even at low voltages, in particular less than 5V during the starting process of a motor in which the voltage drops very quickly in the short term, is possible. This increases the overall reliability of the engine control unit.

According to a further preferred development, the device for controlling at least the third switch comprises a recognition of errors of the fourth means. The advantage here is that costs can be reduced because both the device controls the third switch and detects errors of the fourth means. This achieves the highest possible integration of the control and monitoring components of the engine control unit.

drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Show it:

Fig. 1 is an engine control unit in a simplified manner for driving a

Circuit according to a first embodiment of the present invention in symbolic logic representation;

2 shows a motor control device for driving a circuit according to a first embodiment of the present invention in a circuit diagram.

Fig. 3a, an engine control unit for driving a in a simplified

Diagram;

Fig. 3b, an engine control unit for driving a in a simplified

Circuit diagram in the event of a short circuit.

Description of exemplary embodiments

In the figures, like reference numerals designate the same or functionally identical elements. 1 shows, in a simplified manner, a motor control device for driving a circuit according to a first embodiment of the present invention in symbolic logic representation. In Fig. 1, reference numeral 1 denotes a first signal applied to a first input of the motor control device V (see Fig. 2) according to the first embodiment. A module 67 comprising a

Low-side power amplifier module 6a in the form of e.g. a starter output module, in particular an R2S2-Endst.ufenbaust.eins, and a the output module 6a downstream inverter 7, provides a second signal 1 a available. The first signal 1 and the second signal 1 a cooperate in such a way that a virtual second switch 5 b is formed. The virtual second switch 5b is designed in the form of an AND gate. The output of this virtual second switch 5b is connected to a first switch 5a for controlling this first switch 5a. At the first switch 5 a is another signal 2, here in the form of the battery voltage 2, on. If the second switch 5b is closed, that is to say a corresponding signal is present at the output of the second switch 5b, the first switch 5a is switched such that the battery voltage 2 then also contacts a line 2a which is connected to the output of the switch 5a ,

Starting from the first switch 5 a, further switches 4 a, 4 b are connected to the line 2 a, which provide the battery voltage 2 for external consumers or circuits 3 a, 3 b, for example a starter or a fuel pump, via corresponding connections so that they are energized become. The switches 4a, 4b are also designed as logical AND gates.

The switch 4a is further connected to a line 8a, and the switch 4b is connected to a line 8b. A signal, for example from a microcontroller 10 (see FIG. 2), which actuates the switches 4a, 4b and controls the circuits 3a, 3b, is provided in each case via the lines 8a, 8b.

2 shows a motor control apparatus for driving a circuit according to the first embodiment of the present invention in a circuit diagram.

In Fig. 2, a motor control device V according to the first embodiment is shown in a circuit diagram. At a first input 20 of the engine control unit V is a first signal 1, when a switch 20 ', for example by turning a Zündschlüs- A vehicle is closed to start the vehicle. As a result, a main relay 12 is actuated, so that then in a line 2 at a first switch 5a on the input side, a battery voltage is applied. At the same time, a microcontroller 10 receives a signal of a voltage regulator chip 1 1 connected to it via a line 40, which in turn detects that the first signal 1 is applied to the engine control unit V. The microcontroller 10 then switches on a module 13, 14 via a line 41, reference numeral 13 (in FIG. 1: 6a) designating an output stage component (low-side output stage, in particular starter output stage component R2S2) and denoted by reference numeral 14 (in FIG 1: 7) an inverter in the form of a transistor. The module 13, 14 (in Fig. 1: 67) generates an outgoing signal 1 a. The signals 1 and 1 a then cooperate in such a way that a virtual second switch 5b is formed, which serves to control the first switch 5a. The second switch 5b controls the first switch 5a in such a way that the first switch 5a is switched on only when a signal 1 is present and at the same time when the corresponding signal 1a of the module 13, 14 is applied, so that then the battery voltage in a circuit or line 2a which is connected to the output of the switch 5a is provided.

From this circuit 2a and line 2a again branches lines 4a 'and 4b' to switches 4a, 4b, which connected to the engine control unit V at outputs 20a, 20b circuits 3a, 3b, for example, for a starter relay of the engine of a vehicle or a Fuel supply, when the corresponding switch 4a, 4b is turned on. In order to control the switches 4a, 4b, a respective control line 8a, 8b is provided between the microcontroller 10 and the respective switch 4a, 4b. For example, to start the engine, the microcontroller 10 then controls both the starter by switching on the switch 4a and the fuel pump by means of switch 4b when they are connected to the engine control unit V via the corresponding lines 3a, 3b.

Between the outputs of the switches 4a, 4b and the outputs 20a, 20b of the engine control unit V for connecting the circuits 3a, 3b diagnostic lines 1 1 a, 1 1 b are arranged, which are connected to corresponding inputs of the microcontroller 10. Finally, a diagnostic line 1 1 c is connected to the circuit 2a, which is also connected to an input of the microcontroller 10 ller. These diagnostic lines 1 1 a, 1 1 b, 1 1 c serve to LER of the engine control unit V and errors in the circuits connected via corresponding lines 3a, 3b to detect, distinguish and document. The documentation of these errors takes place, for example, in a fault memory of the microcontroller 10, which has an external connection for a diagnostic tool. The diagnosis of the errors takes place by means of analog-digital

Converters in the microcontroller 10. Software which runs on the microcontroller 10 then determines the respective errors on the basis of various tolerance threshold values for the voltage which is made available via the lines 11a, 11b, 11c.

By way of example, the recognition of an internal fault of the engine control unit V (FIG. 3 a) and an error in an external electric circuit (FIG. 3 b) by the engine control unit V will be described below by the example of an engine control unit V according to a first embodiment.

In Fig. 3a is a simplified view of FIG. 2 is shown with a first switch 5a and a second switch 4a, which controls a starter relay 30 of a vehicle via a line 3a. Next, a diagnostic line 1 1 a for the second switch 4a and a diagnostic line 1 1 c for the first switch 5a. The diagnostic lines 1 1 a, 1 1 c are connected according to the arrangement in Fig. 2 with a microcontroller (not shown here) and grab a voltage at the output of the respective switch 4a, 5a from error of the engine control unit V or the circuit for to detect the starter relay 30.

First, a faultless state, that is, without the bridging of the starter relay 30 by the short circuit K, described.

In a normal operation of a vehicle, the switch 5a is turned on, that is, the battery voltage is applied to the subsequent line 4a '. However, the switch 4a, which controls a starter relay 30, is turned off, ie the battery voltage is not applied to the line 3a. Accordingly, a voltage is measured in the diagnostic line 1 1 c by means of an analog-to-digital converter, which is above a certain tolerance threshold A, since the switch 5 a is turned on. If the switch 5a were off, a voltage below the tolerance threshold A would be measured. When switched off switch 4a can not be determined based on the diagnostic line 1 1 a, to which a 5V diagnostic voltage is applied to diagnose errors, whether a short circuit K of the starter relay 30 is present. In order to determine whether a short circuit K is present, the switch 4a is turned on for a very short time and at least the voltage in the diagnostic line 11a is measured by means of an analog-to-digital converter in the microcontroller 10. An error-free operation is detected when an impedance of the connected via the diagnostic line 1 1 a circuit 3a for certain DC and AC voltages above a certain tolerance threshold B. In the case of a short circuit K, a smaller voltage value or an impedance smaller than the tolerance threshold value B for the specific DC or AC voltages is determined in the diagnosis line 11a, so that then a short circuit K to ground M is determined accordingly. In this case, the microcontroller 10 then controls the switch 4a and the switch 5a so that they are switched on and / or off accordingly to allow an analysis or repair of the short circuit K. In the case of the starter relay 30 then both the switch 4a and the switch 5a can be turned off to prevent spinning of the starter relay 30.

A case of a short circuit K in the switch 4a is now shown schematically in FIG. 3b with reference to a simplified diagram according to FIG. Without a short circuit K, a voltage above the corresponding tolerance threshold value A is measured when the switch 4a is switched off and the switch 5a is switched on at the diagnostic line 11, whereas in the diagnosis line 11a only the usual voltage is measured when the switch 4a is switched off.

If the switch 4a is now bridged by a short circuit K, there is a direct connection between the output of the switch 5a and the circuit 3a of the starter relay 30.

If the engine is started, no error is initially diagnosed, since for its start both the switch 5a and the switch 4a must be turned on to confirm the starter. However, if the switch 4a is then switched off as a result of a successful starting process of the engine, so that the starter does not spin, or is the engine already in operation. was, however, in the corresponding diagnostic line 1 1 a still the same voltage as measured in the on state. The microcontroller 10 then detects an internal fault of the engine control unit V and then optionally shuts off the switch 5 a in order to avoid further damage to the engine control unit V or the connected circuit 3 a.

A determination and differentiation of further internal and external errors, such as a short circuit of the starter with the battery voltage, an interruption of the line 3a outside of the engine control unit V or a short circuit of the switch 5a is based on the diagnostic lines 1 1 a,

1 1 c or the microcontroller 10 possible. In addition, in order to distinguish the individual errors from each other, the switch 4a and the switch 5a can be alternately turned on and off by the engine control unit to detect and discriminate the various types of errors.

A separate line to the starter or a short to the battery is measured for example via diagnostic lines 1 1 a, 1 1 c in the off state of the switch 4a, whereas a short circuit to ground M during the on state of the switch 4a is measured. In the event of a break in a line in the connected circuit 3a, for example, the impedance of the connected circuit is determined by means of the diagnostic line 1 1 a. If the impedance is above a certain tolerance threshold C, e.g. several hundred kilohms, an interruption is detected as an error. If the impedance is below a certain tolerance threshold D, for example a few kiloohms, no error is caused by the

Microcontroller 10 detected. The tolerance threshold D is determined in accordance with typical resistance values of the connected circuit. Furthermore, certain errors must be continuously checked by the engine control unit V. For example, to prevent a connected to the engine control unit V fuel pump uncontrollably promotes fuel by a switch 4a, via which a fuel pump is connected, is bridged by a short circuit. In this case, then the switch 4a and the switch 5a are turned off within 500 ms, if a corresponding

Error is detected. Furthermore, it is necessary after a first detection of an error to detect the error within a fixed period again, for example, to detect a short circuit K on the basis of a loose and strikethrough cable and then turn off the switch 4a and the switch 5a, to damage the Device and to avoid external circuits.

Since the present invention has been described above with reference to preferred Ausführungsbei- games, it is not limited thereto, but on a variety of

Modifiable and modifiable.

Claims

claims

1 . Motor control device (V) for driving a circuit (2a), in particular a starter in a vehicle,

comprising at least

a first means (31) for providing a first signal (1), in particular an ignition signal,

a second means (30) for providing a voltage (2) for the circuit (2a),

a third means (32) for connecting the circuit (2a),

a first switch (5a) disposed between the second means (30) and the third means (32) for controlling the circuit (2a), and

a fourth means (13, 14) for generating a second signal (1 a), wherein the first signal (1) with the second signal (1 a) for forming a virtual second switch (5b) cooperates to turn on or off the circuit (2a) by means of the first switch (5a).

2. Engine control unit according to claim 1, wherein the first and second means (30, 31) comprises an input of the engine control unit (V) and the third means (32) comprises an output of the engine control unit (V).

3. Engine control unit according to claim 1, wherein

at least one third switch (4a, 4b) is arranged between the first switch (5a) and an output (20a, 20b) of the engine control unit (V) for controlling a second electric circuit (3a, 3b), in particular for a fuel pump.

4. Engine control unit according to claim 1, wherein

a device (10), in particular a microcontroller, is provided for controlling at least the third switch (4a, 4b). Engine control unit according to claim 1, wherein

at least one device (10, 11a, 11b, 11c) is arranged to detect faults.

Engine control unit according to claim 5, wherein

the at least one device (10, 1 1 a, 1 1 b, 1 1 c) for detecting errors analog-to-digital converter (10).

Engine control unit according to at least claim 5,

wherein errors of the engine control unit (V) and / or errors of the circuit to be controlled (3a, 3b) by means of the means for detecting errors (10, 1 1 a, 1 1 b, 1 1 c) at least recognizable and in an error memory (10 ) are storable.

Engine control unit according to at least claim 1, wherein

the fourth means (13, 14) a low-side power amplifier (13), in particular one

R2S2 power amplifier module.

Engine control unit according to claim 4, wherein

the device (10) for controlling at least the third switch (4a, 4b) comprises a recognition of errors of the fourth means (13, 14).

10. A method for driving a circuit (2a), in particular a starter of a vehicle comprising the steps

Providing a first signal (1), in particular an ignition signal, providing a second signal (1 a), which is generated indirectly from the first signal (1) and wherein the first signal (1) with the second signal (1 a) for forming a virtual second switch (5b) cooperates to control a first switch (5a) for turning on or off the

Circuit (2a).