WO2015039658A1

WO2015039658A1 - Method for supplying a control device

Info

Publication number: WO2015039658A1
Application number: PCT/DE2014/200375
Authority: WO
Inventors: Jürgen GERHART; Martin Zimmermann
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2013-09-19
Filing date: 2014-08-04
Publication date: 2015-03-26
Also published as: CN105556182A; CN105556182B; DE112014004309A5; DE102014215263A1

Abstract

The invention relates to a method for maintaining a safe driving state of a motor vehicle by an actuator which is driven by a control device (1), wherein the control device (1) is connected to an external energy supply via a current-carrying supply line (6) and the voltage across the supply line (6) is measured, wherein a second current-carrying line (19) for supplying the control device (1) is activated when an undervoltage is identified on the supply line (6). In a method in which structural expenditure and costs are reduced, a current-carrying line (19) which is present in the motor vehicle in any case is used as the second current-carrying line for supplying a logic module (5), which is contained in the control device (1), in order to permanently maintain an emergency state of the motor vehicle.

Description

METHOD FOR SUPPLYING A CONTROL DEVICE

The invention relates to a method for maintaining a safe driving state of a motor vehicle by an actuator according to the preamble of claim 1 and a control device for carrying out the method according to the preamble of claim 4.

The invention relates to a method for maintaining a safe driving condition of a motor vehicle by an actuator, which is controlled by a control unit, wherein the control unit is connected via a current-carrying supply line to an external power supply and the voltage is measured on the supply line, wherein upon detection of an undervoltage on the supply line, a second current-carrying line for supplying the control unit is activated, and a control device for carrying out the method.

Such a control unit can be used for example in an automated manual transmission in a motor vehicle. The automated manual transmission can be, for example, a parallel-shift transmission (PSG) - also known as a dual-clutch transmission - with two sub-drive trains, each with a partial transmission with multiple, switchable by one or more gear actuators gears, each sub-drive train is assigned a friction clutch, the is operated by a clutch actuator (DE 10 2008 050 289 A1). The involved gear actuators and clutch actuators are controlled by one or more of the control devices according to the invention. The actuation is controlled by a control unit by means of a control and driver unit.

The control devices according to the invention are also provided for fail-safe control of other electrically operated actuators, for example for controlling clutch and / or transmission actuators in automated clutch systems, for example in EKM systems (electronic clutch management), clutch-by-wire systems and all kinds of automated Manual transmissions (ASG, PSG). Furthermore, these control units for fail-safe operation of the actuators of disconnect couplings in hybrid vehicles and for operating parking brake actuators in motor vehicles and for controlling other actuators in Motor vehicle, such as actuators for actuating switching elements in the drive train of a motor vehicle, such as jaw clutches provided.

The control unit is supplied with electrical energy from an external energy source by means of a first current-carrying line. In order to prevent the power supply of the control unit from failing in the event of a line break, fuse blow-out or dropping of the plug, a second current-carrying lead is additionally present in parallel with the first current-carrying line Provide line that is automatically switched on when the first line is interrupted.

In addition, it is known that the described automated drive systems must switch temporarily and permanently in the failure of the power supply in a designated as brake mode emergency mode, in which the control unit arranged power transistors shorted in the ground path and the power transistors connected in the current path must be closed high resistance or the other way around. To sustain this brake mode permanently, an energy storage device is available.

The disadvantage here is that the brake mode can not be maintained permanently, since the energy storage has only a limited capacity. However, a permanent maintenance of the brake mode is particularly important if, for example, a clutch against the clutch force must be kept in a certain position in order to maintain a driving condition of the motor vehicle and to avoid accidents.

The invention is thus based on the object of specifying a method for maintaining a safe driving state of a motor vehicle by an actuator, in which the driving state is maintained even with interruption of a power supply line with an external power supply.

According to the invention the object is achieved in that as a second current-carrying line for supplying a, contained in the control unit logic module in the motor vehicle itself present current-carrying line is used to the emergency condition of the motor vehicle to keep it permanently upright. By using a self-existing current-carrying line eliminates the installation of an additional electrical power supply line. As a result, the structure of the control unit is simplified and still allows sustained maintenance of the driving condition of the motor vehicle, since the logic module, which is of particular importance for the activation of the actuator, is put into such a state by the current-carrying line present in the motor vehicle the driving condition of the motor vehicle remains unchanged and dangerous situations are prevented. Another advantage of such, even in a power failure active logic module is the ease of diagnostics and the ability to continue to communicate with other control devices, thereby possibly initiate vehicle reactions such as engine intervention or engine shutdown and / or to warn the driver.

Advantageously, as an existing in the motor vehicle current-carrying line lying on battery plus ignition or vehicle ground is used, which allow the supply of the logic module delay and permanently in case of failure of the control unit supply.

In one embodiment, the logic module switches after the detection of the undervoltage on the current-carrying supply line, the motor vehicle via a clutch actuator permanently in a brake mode in which a clutch of the motor vehicle is maintained at a level which this upon detection of undervoltage on the current-carrying supply line Control unit has taken. By this simple method, a closing of the clutch against the coupling force is prevented or slowed down, whereby dangerous situations for the motor vehicle and its occupants are prevented. Slow clutch closure can be tolerated if other safety-related vehicle responses, such as driver warning and engine intervention, are made over time. On a separate energy storage for the logic module can be omitted.

A development of the invention relates to a control device for controlling an actuator, wherein the control device is connected to an external power supply by means of a current-carrying supply line, and a second current-carrying line is present, which can be switched on detection of an undervoltage on the current-carrying supply line or is automatically usable. In a control device, which maintains the actuator in case of failure of the power supply via the first current-carrying supply line in the current driving state, is used as a second current-carrying line for supplying a logic module in the motor vehicle itself existing live line to the driving condition, preferably an emergency condition, to maintain the motor vehicle permanently. This is a particularly cost-effective and structurally advantageous method, as can be dispensed with the arrangement of additional redundant current-carrying lines in or on the control unit. The still active logic module is easy to diagnose, for example via the CAN bus of the motor vehicle, and there remain possibilities that the control unit can communicate with other control devices of the motor vehicle. In particular, when the fault is detected, vehicle reactions may be triggered by other control devices, such as engine intervention or engine shutdown, or driver warning.

Advantageously, the logic module is connected to a lying on battery plus ignition or vehicle ground. Since these two lines are present per se in the motor vehicle, they can be easily connected to the controller and in the controller to the logic module to maintain the logic module in the activated state.

In one embodiment, a Verpolschutzelement is arranged in the ignition. This polarity reversal protection element can be formed in the simplest case as a diode. By a further diode can be prevented that in case of failure of the power supply line of the control unit, the ignition connected to the battery plus ignition line is overloaded. In a simple variant, the further diode is designed as a germanium diode and the polarity protection diode on the current-carrying supply line is a silicon diode, in order to allow the current across the ignition to approach zero due to different voltage drops across the two diodes.

In a further variant, a current limiting element, preferably a resistor or a transistor circuit, is arranged in the ignition line. This is always important when the current limit in normal operation, caused by the different diodes - since the other diode has a lower voltage drop than the polarity reversal diode - is not sufficient and additional security is to be created. In a further embodiment, the logic module is connected to the vehicle ground via a housing of the control unit. This is an extension to have a second ground supply for the logic part even in case of failure of belonging to the power supply line ground line (terminal 31).

Furthermore, a further reverse polarity protection element and / or a further current limiting element are arranged in the connection with the vehicle ground. The polarity reversal protection of the housing is necessary if the housing is also to be protected against reverse polarity. Similar to the ignition cable and the connection to vehicle mass on the Steuergerätses- Chasis, are running current limited. The current limit both on ground and on the supply side (ignition cable) is such that at maximum logic current a maximum voltage drop is not exceeded. Thus, in the case of emergency operation, the emergency supply via the housing ground is quite permissible.

In one embodiment, a plug connection is formed for connecting the ignition line and / or the vehicle ground.

A further development of the invention relates to a control device for controlling an actuator, wherein the control device is connected to an external power supply by means of a current-carrying supply line and the power line associated ground line and a second ground line is present, which in case of disturbance of, the current-carrying line associated ground line switchable or automatically usable. In a control device which maintains the actuator in case of failure of the power supply via the ground line in the instantaneous driving state is used as a second ground line to power a logic module, in the motor vehicle inherent mass, preferably the housing ground of the controller to the driving condition, preferably one Run-flat state, to maintain the motor vehicle permanently. This is a particularly cost-effective and structurally advantageous method, as can be dispensed with the arrangement of additional redundant current-carrying lines in or on the control unit. The invention allows numerous embodiments. One of them will be explained in more detail with reference to the figures shown in the drawing.

It shows:

Figure 1 shows an embodiment of a control device according to the invention.

According to FIG. 1, the control unit 1 operates an actuator 2 comprising a plurality of electric motors for actuating a parallel shift transmission which includes two friction clutches. The components and lines for controlling and powering the actuator are omitted for clarity. Only a driver 3 and an output stage 4 are shown schematically. A logic module 5 in the form of a microprocessor, which is located at the terminal GND, assumes the control and computing operations of the control unit. 1

The control unit 1 is connected to the vehicle electrical system of the motor vehicle by means of a first current-carrying line 6, in particular the so-called "terminal 30" (battery plus input). Return to battery negative or ground). By means of these lines 6, 7, the control unit 1 is supplied with energy. The current-carrying line 6 is protected by means of a fuse F1. Behind the respective input 8, 9 of the control unit 1, a shunt resistor 10, 1 1 is provided for each line 6, 7. In the present example, the shunt resistor 10 of the first current-carrying line 6 is bridged by a comparator 12.

In the line 7, a polarity reversal protection 13 is disposed in front of the shunt resistor 1 1, wherein the shunt resistor 1 1 is bridged by a second comparator 14. The current-carrying line 7 is connected to a housing 15 of the control unit 1, which also has a current limiting element in the form of a shunt resistor 16 and a Verpolschutzele- element 17. Due to the arrangement on the housing 15, the ground line 7 is on vehicle ground. The current-carrying line 6 is connected via a logic supply 18 to the logic module 5, to the logic supply 18 also an ignition line 19 is connected. The ignition line 19 of the motor vehicle is referred to as terminal 15 and is connected to battery plus. By means of this ignition line 19, not only the logic module 5, but also the driver 3 is supplied with energy when the power supply of the line 6 is interrupted. In the ignition 19 a polarity reversal 20 and optionally a current limiting element 21 are arranged.

Trained as a microprocessor logic module 5 is connected via the driver 3 to the power amplifier 4, which controls the actuator 2, in particular the electric motors. In addition, there is a trained as a watchdog circuit monitoring circuit 22, which is in correlation with the logic module 5. Since the control unit 1 for the logic module 5 has a further connection line (ignition line 19), the logic module 5 can be operated independently even if there are faults in the current-carrying line 6 of the control unit 1. As an alternative to the ignition line 19 and the housing ground 15, which replaces the grounding line 7 belonging to the current-carrying line 6, however, a second supply path can also be routed to the control device 1 via a separate plug.

In the normal state, the control unit 1 is connected to the ignition of the ignition via the current-carrying lines 6, 7 with the battery of the motor vehicle. The ignition line 19 is connected to battery plus and the control unit 1 is connected via the housing 15 with the vehicle ground. The state of the lines 6, 7 including the fuse F1 is tested via the voltage drop across the shunt resistor 10, 1 1. The comparator 12 measures the voltage which is applied in front of the shunt resistor 10 and which after the shunt resistor 10 in the first current-carrying line 6. If there is no interruption at the first current-carrying line 6, then the comparator 12 will detect a difference> 0 in the voltages before and after the shunt resistor 10. However, if a line break, a failure of the fuse F1 or a plug failure has occurred, the comparator 12 will detect no voltage difference from the voltages before and after the shunt resistor 10. The comparator 12 transmits its measurement results to the input A D1 of the logic module 5. Alternatively, it is also conceivable that instead of the shunt resistor 10, the voltage drop across a polarity reversal protection is measured. The ground line 7 is checked in the same way with the second comparator 14, which measures the voltage before and after the shunt resistor 1 1 and reports its measurement results to the input A D2 of the logic module.

In the event of failure of the supply line 6, the ignition line 19 is automatically available via the logic supply 18. The diode D1 prevents that in case of failure of the current-carrying line 6 or the fuse F1, the ignition line 19 is overloaded. The current limit of the ignition line 19 is optional. It must be ensured that a minimum current for maintaining the logic supply can be provided without significant voltage drop in the event of a fault.

Since the control unit 1 is connected in low resistance to the housing 15 and thus also the vehicle ground, the ground line 7 must be protected against reverse polarity. The reverse polarity protection of the housing 15 in turn is only necessary if the housing 15 is to be protected against reverse polarity.

As soon as the microprocessor 5 does not detect any defined voltage drop via its inputs A D1 or A D2, the electric motors of the actuator 2 are switched off and a brake mode is initiated. The status is communicated to other control units via a CAN bus (not shown). Thus, in the presence of a fault in the supply lines 6 and / or 7 emergency operation is possible. The driver 3, as well as the logic module 5, continues to be supplied with voltage and is thus able to switch the brake mode permanently and at short notice. In the context of the parallel shift transmission this means that the clutch is held by the brake mode in the state which it has assumed on detection of the power interruption in the line 6 or 7.

In another variant, in the event of a fault, the logic module 5 designed as a microprocessor is reset via the monitoring circuit 22, which means that the outputs of the microprocessor 5 are high-impedance. The brake mode is brought about by a defined resistance circuit at the input of the driver 3 (pull-up / pull-down). In this case, the Diagnosis and thus the function of the switch DIAG1, DIAG2 and the read-back line DIA- G _En dstufe directly via the monitoring circuit 22 done.

In a further variant, the power transistors of the output stage 4 are connected directly to the actuator 2, that is, behind the output of the driver 3. It must be ensured that the driver goes to Disable and that its outputs are high-impedance. This disable switching of the driver and the readback of the output stage 4 can be done by the microprocessor 5 and / or by the monitoring circuit 22.

It is also possible that the error case and the subsequent setting of a safe state, a brake mode, be simulated. In this case, the malfunction fault on the line 6 and / or fuse F1 is simulated defectively via the switch DIAG1 of the microprocessor 5. The desired function of switch DIAG1 can be diagnosed via the reduced voltage drop across shunt resistor 10 via input A D1.

The fault in the ground line 7 is simulated via the switch DIAG2. Switching off the polarity reversal protection reduces the current flow in the shunt resistor 1 1 of the ground line 7. The voltage measurement via A D2 provides the diagnosis. The state of the brake mode can be diagnosed via the lines DIAG _En dstufe from the microprocessor 5 and / or from the monitoring computer.

The explained solution has the advantage that no additional external supply lines are necessary, but the already existing supply lines (ignition line and housing ground line) are used.

Reference numerals control unit

actuator

driver

final stage

logic module

Power line

ground line

Input of the control unit

Shunt resistor

comparator

Reverse polarity protection

comparator

Frame ground

Shunt resistor

Verpolschutzelement

logic supply

Ignition

Reverse polarity protection

Current limiting element

monitoring circuit

Claims

Patent claims

Method for maintaining a safe driving state of a motor vehicle by an actuator which is controlled by a control device (1), the control device (1) being connected to an external power supply via a current-carrying supply line (6) and the voltage on the supply line (6) is measured, wherein when an undervoltage is detected on the supply line (6), a second current-carrying line (19) is activated to supply the control device (1), characterized in that as the second current-carrying line to supply one contained in the control device (1). Logic module (5) a current-carrying line (19) present in the motor vehicle is used to permanently maintain an emergency running state of the motor vehicle.

Method according to claim 1, characterized in that an ignition line (19) connected to battery positive or a vehicle ground is used as the current-carrying line present in the motor vehicle.

Method according to claim 1 or 2, characterized in that, after detecting the undervoltage on the current-carrying supply line (6), the control device (1) permanently switches the motor vehicle into a brake mode via a clutch actuator (2), in which a clutch of the motor vehicle is maintained at a level that it reached when the undervoltage was detected on the live supply line (6).

Control device for controlling an actuator, the control device (1) being connected to an external energy supply by means of a current-carrying supply line (6) and a second current-carrying line (19) being present, which can be switched on when an undervoltage is detected on the current-carrying supply line (6). can be used automatically, characterized in that a current-carrying line (19) present in the motor vehicle is used as the second current-carrying line for supplying a logic module (5) in order to permanently maintain the driving state, preferably an emergency running state, of the motor vehicle.

5. Control device according to claim 4, characterized in that the logic module (5) is connected to an ignition line (19) connected to battery positive or a vehicle ground.

6. Control device according to claim 5, characterized in that a polarity reversal protection element (20) is arranged in the ignition line (19).

7. Control device according to claim 5 or 6, characterized in that a current limiting element (21), preferably a resistor or a transistor circuit, is arranged in the ignition line (19).

8. Control device according to one of claims 5, 6 or 7, characterized in that the logic module (5) is connected to the vehicle ground via a housing (15) of the control device (1).

9. Control device according to claim 8, characterized in that the connection to vehicle ground has a further polarity reversal protection element (17) and/or a further current limiting element.

10. Control device for controlling an actuator, the control device (1) being connected to an external energy supply by means of a current-carrying supply line (6) and a ground line (7) assigned to the current-carrying line (6), and a second ground line (15) being present, which can be switched on or used automatically in the event of a fault in the ground line (7) assigned to the current-carrying line (6), characterized in that the second ground line for supplying a logic module (5) is a ground (15) that is present in the motor vehicle, preferably the ground line (15). Housing mass (15) of the control unit (1) is used to permanently maintain the driving state, preferably an emergency running state, of the motor vehicle.