DE102012024719A1 - Electronic steering lock for vehicle, has activation signal activating controller when deviation of applied electric voltage from reference voltage by comparator circuit is applied to drive unit, which is arranged on bridge branch - Google Patents

Abstract

The lock has an electric drive unit (3) for actuating a blocking element in locking direction and unlocking direction. An H-bridge circuit couples the electric drive unit to a voltage supply. A comparator circuit (1) compares applied electric voltage (UAnt) and reference voltage (Uref high, Uref low) of the electric drive unit. Activation signal activates a controller (4) when deviation of the applied electric voltage from the reference voltage by the comparator circuit is applied to the electric drive unit, which is arranged on a bridge branch. An independent claim is also included for a method for operating an electronic steering lock for a vehicle.

Description

The invention relates to an electronic steering lock for a vehicle, comprising at least one locking element for locking the steering, at least one electric drive unit for actuating the locking element in a locking direction and an unlocking direction, at least one H-bridge circuit for coupling the electric drive unit with a power supply and at least one Controller for monitoring operation of the drive unit.

Furthermore, the invention relates to a method for operating an electronic steering lock for a vehicle, wherein the steering of the vehicle is locked or unlocked by means of at least one, actuated by an electric drive unit locking device is coupled by means of at least one H-bridge circuit, the electric drive unit with a power supply and By means of at least one controller in the activated state, an operation of the drive is monitored.

From the prior art steering wheel locks, also known as steering wheel lock, are generally known for vehicles which serve to protect against unauthorized use of the vehicle. This locking takes place in the case of an electronic steering wheel lock or an electronic steering lock (in short: ELV) by means of electrically operated actuators. To avoid locking the steering while driving the vehicle, safety circuits are provided. These safety circuits include a controller permanently activated during driving to detect hardware faults of the electronic steering lock.

From the DE 10 2009 045 224 A1 For example, a vehicle steering lock assembly is known for coupling to a bus, the bus being for communicating messages to instruct a lock or unlock steering. Furthermore, a control device is provided which generates an enable signal which, in the case of a stoppage of the vehicle, is a square-wave signal having a predetermined frequency and a predetermined duty cycle. The vehicle steering lock assembly includes a power switch coupling a drive motor for a locking pin to a supply voltage forming a branch of an H-bridge circuit, wherein turning on the power switch connected to the drive signal of the logic circuit is a prerequisite for moving the drive motor in the locking direction. Furthermore, a controller coupled to the bus that outputs a first control signal for turning on the power switch upon receipt of a message for instructing a lock, and a safety circuit whose input is coupled to the enable signal of the controller and outputs a second control signal are provided. The safety circuit is a simple alternating signal detection circuit which applies the second control signal when an alternating signal is present at its input. Furthermore, the vehicle steering lock assembly comprises a logic circuit which combines the first control signal with the second control signal and applies a drive signal which turns on the power switch to a control terminal of the power switch only if both the first and the second control signal are present. An additional input port of the controller is coupled to the controller enable signal, and the controller is configured to analyze the enable signal and apply the first control signal upon receiving a lock instruct message only if the enable signal is a square wave of the predetermined frequency and the predetermined duty cycle.

It is an object of the present invention to provide an improved electronic steering lock for a vehicle over the prior art and an improved method for operating an electronic steering lock for a vehicle.

With regard to the electronic steering lock, the object is achieved by the features specified in claim 1 and in terms of the method by the features specified in claim 5.

Advantageous embodiments of the invention are the subject of the dependent claims.

The electronic steering lock for a vehicle comprises at least one locking element for locking the steering, at least one electric drive unit for actuating the locking element in a locking direction and an unlocking direction, at least one H-bridge circuit for coupling the electric drive unit to a power supply and at least one controller for monitoring an operation of the drive unit.

According to the invention, a comparator circuit is provided for comparing an electrical voltage applied to the electric drive unit with at least one reference voltage, the comparator circuit being coupled to the controller and, in the event of a deviation of the voltage applied to the electrical drive unit arranged in a bridge branch, from the at least one reference voltage of the Comparator circuit, an activation signal for activating the controller can be generated.

In this way, a particularly energy-saving operation of the electronic steering lock, in particular of the controller, allows in an advantageous manner, since this is only operated when monitoring the operation of the drive unit is required. During vehicle driving, the controller is deactivated when there is no fault within the electronic steering lock. A permanent operation of the controller is thus avoided. This in turn results in an increase in the life of the components of the controller. In the active state, the operation of the drive unit is monitored by means of the controller, which is deactivated in the event of a malfunction, so that a locking of the steering by means of the blocking element due to a malfunction of the drive unit can be avoided. Also, due to the "awakening" of the controller and the monitoring and diagnosis of the operation of the electronic steering lock performed in the active state thereof, it is possible to issue an indication to the driver informing him of the presence of a fault within the electronic steering lock. That is, the display of the error is possible with very little or further reduced energy consumption.

According to a further development of the device, the comparator circuit is designed in such a way that the activation signal can be generated by the at least one reference voltage in the case of a positive and a negative deviation of the electrical voltage applied to the electric drive unit. Such monitoring of the electrical voltage and corresponding generation of the activation signal enables the controller to be activated only when the electronic steering lock is active or an error occurs within it.

In one embodiment of the device, the comparator circuit comprises a plurality of operational amplifiers. By means of such operational amplifiers, the comparison of the electrical voltage applied to the electric drive unit with the at least one reference voltage can be carried out exactly.

Alternatively, the comparator circuit is constructed as a flip-flop circuit, which preferably comprises a plurality of flip-flops. By means of such a flip-flop circuit, the comparator circuit can be realized with a particularly low cost.

In a further embodiment, the H-bridge circuit is formed of two arranged on a voltage side and two arranged on a ground side and H-shaped interconnected switching elements, in particular transistors, wherein the bridge branch is formed by means of a cross-connection, in which the drive unit is arranged. This allows movement of the drive unit in different directions, i. H. the locking direction and the unlocking direction. The formation of the switching elements as transistors allows particularly low material and manufacturing costs in the realization of the H-bridge circuit. Furthermore, the H-bridge circuit is particularly durable due to the use of transistors as switching elements and their low wear and is characterized by fast switching times.

In the method for operating an electronic steering lock for a vehicle, the steering of the vehicle is locked or unlocked by means of at least one locking element actuated by means of an electric drive unit. By means of at least one H-bridge circuit, the electric drive unit is coupled to a power supply and by means of at least one controller, an operation of the drive is monitored in the activated state.

According to the invention, an electrical voltage applied to the electrical drive unit is compared with at least one reference voltage by means of a comparator circuit coupled to the controller, and an activation signal is generated from the at least one reference voltage by means of the comparator circuit by a deviation of the voltage applied to the electric drive unit Controller is activated.

The inventive method advantageously allows a particularly energy-saving operation of the electronic steering lock, in particular the controller, since this is only operated when monitoring the operation of the drive unit is required. A permanent operation of the controller is thus avoided. This in turn results in an increase in the life of the components of the controller.

In particular, the drive is monitored by the controller in the activated state and deactivated in the event of a malfunction. Thus, a Verrieglung the steering by means of the locking element due to a malfunction of the drive unit is avoided. Also, due to the "wake up" of the controller and the same in the active state performed monitoring and diagnosing the operation of the electronic steering lock allows the driver can be issued an indication of this on the existence of a fault within the electronic Steering lock informs. That is, the display of the error is possible with very little or further reduced energy consumption.

Furthermore, according to a development of the method by means of the controller for deactivating the drive, the H-bridge circuit is de-energized by means of a control of a control unit for power distribution. By means of such a circuit of the H-bridge circuit in a de-energized state, the drive unit is particularly quickly and reliably deactivated.

Alternatively, by means of the controller for deactivating the drive, a first unlocking switching element arranged on a voltage side of the H-bridge circuit, in particular a first unlocking transistor, and a second unlocking power switching element arranged on a ground side of the H-bridge circuit, in particular a second unlocking transistor, simultaneously into an electrically conductive one State switched. As a result, activation of the drive unit in the locking direction is reliably prevented. At the same time in the permanent voltage branch, in particular the so-called "terminal 30 Caused an overload reaction, which leads to the triggering of an arranged there electrical security element, such as a fuse. Thus, the H-bridge circuit is safely disconnected from the power supply.

According to a further alternative, a switching element arranged between the H-bridge circuit and the voltage supply, in particular a transistor, is switched to an electrically nonconductive state by means of the controller for deactivating the drive. This allows for a quick interruption of the power supply of the H-bridge circuit and on the other a reversible interruption of this. Since both the switching element arranged between the H-bridge circuit and the voltage supply and the switching element of the H-bridge circuit are controlled by means of the controller, a coordinated activation of the switching elements is possible. In particular, the switching elements of the H-bridge circuit are switched before the Unterberechung the power supply by means of the further switching element such that the H-bridge circuit is in dependence on the particular situation in a defined safe state.

According to an alternative embodiment of the method, when the electric voltage applied to the electric drive unit deviates from the at least one reference voltage, a further activation signal is generated by means of the comparator circuit, by means of which a switching element, in particular arranged between the H-bridge circuit and the voltage supply, for deactivating the drive a transistor is switched to an electrically non-conductive state. This allows for a quick interruption of the power supply of the H-bridge circuit and on the other a reversible interruption of this. For this purpose, the transistor by means of the further activation signal, which is according to a development of the activation signal for activating the controller, so controlled that it opens the electrical connection between the power supply and the H-bridge circuit and thus the drive unit. However, if after the activation of the controller, its monitoring and diagnosis of the drive unit and the other components of the electronic steering lock indicates that there is no fault, the electrical connection between the power supply and the H-bridge circuit is restored, so that the drive unit is operational.

Embodiments of the invention are explained in more detail below with reference to drawings.

Showing:

1 1 schematically shows a first illustration of a comparator circuit for an electronic steering lock according to the invention,

2 schematically a second representation of the comparator according to 1 .

3 schematically a time course of within the comparator circuit according to 1 occurring electrical voltages,

4 schematically a first embodiment of the electronic steering lock according to the invention,

5 schematically a second embodiment of the electronic steering lock according to the invention,

6 schematically a third embodiment of the electronic steering lock according to the invention,

7 schematically a fourth embodiment of the electronic steering lock according to the invention, and

8th schematically a fifth embodiment of the electronic steering lock according to the invention.

Corresponding parts are provided in all figures with the same reference numerals.

1 shows a first representation of a comparator circuit 1 for an inventive, in the 4 to 8th illustrated electronic steering lock 2 , In 2 is detailed second illustration of the comparator circuit 1 shown.

The comparator circuit 1 comprises two operational amplifiers O1, O2, to which on the input side in each case a reference voltage U _{ref_high} , U _{ref_low,} generated from an operating voltage U1 by means of a voltage divider formed from electrical resistors R2, R3, R4, is supplied. A first reference _voltage U _{ref_high} is supplied to the first operational amplifier O1 and thereby represents an upper reference _voltage . A second reference _voltage U _{ref_low} is supplied to the second operational amplifier O2 and represents a lower reference _voltage .

In an embodiment not shown, so-called flip-flops are used instead of the operational amplifier O1, O2.

Furthermore, by means of a further voltage divider formed from electrical resistors R5, R6 from one to an electric drive unit 3 voltage applied _Ant , ie a supply voltage of the drive unit 3 , an input voltage U _In and supplied to the operational amplifiers O1, O2. By means of the operational amplifiers O1, O2, the input voltage U _{In is} compared with the respective reference _voltage U _{ref_high} , U _{ref_low} , wherein when the lower reference _voltage U _{ref_low is undershot} an activation signal S _{ges is} generated, by means of which a controller 4 the electronic steering lock 2 is activated. The activation signal S _ges is generated from a logical combination of individual signals S1, S2 generated by means of the operational amplifiers O1, O2.

In order to avoid a short circuit between the outputs of the operational amplifiers O1, O2, in each case one, in particular designed as a Schottky diode, diode D1, D2 is provided.

_Exceeds the input voltage U _In the lower reference _voltage U _{ref_low} and _falls below the input voltage U _In simultaneously the upper reference _voltage U _{ref_high} , the activation _signal S _{ges has} the value zero, so that the controller 4 not activated or deactivated.

When the upper reference _voltage U _{ref_high} is _exceeded , the activation _signal S _{ges is} again different from the value zero, so that the controller 4 is activated.

The respective courses of the electrical voltages U, ie the reference _voltages U _{ref_high} , U _{ref_low} , the input voltage U _In , the voltage U _Ant and the activation signal S _ges are plotted against the time t 3 shown.

These time courses are valid for an embodiment in which the resistor R1 is 100 kΩ, the resistor R2 220 kΩ, the resistor R3 38.5 kΩ, the resistor R4 16.5 kΩ, the resistor R5 10 kΩ and the resistor R6 2, 21 kΩ. The voltage U _Ant is at its maximum 12 V, the signal S either 0 V or about 4.8 V. The upper reference _voltage U _{ref_high} is about 1 V and the lower reference _voltage U _{ref_low} about 0.3 V. The operating voltage U _B is 5 V.

4 shows a first embodiment of the electronic steering lock according to the invention 2 , This includes beside the controller 4 and the comparator circuit 1 a blocking element 5 for locking and unlocking the steering of a vehicle. For actuating the blocking element 5 is the electric drive unit 3 provided, wherein the drive unit 3 in an H-bridge circuit 6 is arranged. The H-bridge circuit 6 comprises four independently controllable, designed as power transistors switching elements 6.1 to 6.4 , There are two switching elements 6.1 . 6.2 on a voltage side of the H-bridge circuit 6 and two switching elements 6.3 . 6.4 on a ground side of the H-bridge circuit 6 arranged.

By means of these switching elements 6.1 to 6.4 is the drive unit 3 in a known manner such with a power supply 7 Coupled that the drive unit 3 optionally in a locking direction V and an unlocking E is operable. The power supply 7 includes a permanent voltage branch 7.1 , the so-called "clamp 30 ", And a tension branch 7.2 , the so-called "clamp 31 ", Ie the return of an energy storage, not shown.

The comparator circuit 1 is according to the 1 and 2 trained and with the controller 4 coupled, as - in the description of the 1 to 3 described - at a deviation of the arranged in a bridge branch BZ electric drive unit 3 applied voltage U _Ant of the reference _voltages U _{ref_high} , U _{ref_low} by means of the comparator _circuit 1 an activation signal S _ges for activating the controller 4 is produced.

The controller 4 is still via a data line with an electronic ignition 8th and further with a limit switch 9 coupled the limit switch 9 End positions of a locking mechanism, ie the locking element 5 , detected.

In error-free operation is the controller 4 deactivated while driving the vehicle. Is an error from the comparator in the manner described 1 detected, ie deviates the voltage U _Ant in the manner described by the reference _voltages U _{ref_high} , U _{ref_low} , from the activation signal Sges is generated and the controller 4 is via a so-called wake-up interrupt 4.1 activated.

To operate the controller 4 this has a supply voltage connection 4.2 and a ground connection 4.3 to a voltage regulator 10 on which with the power supply 7 is coupled and an operating voltage for the controller 4 established.

If the activation signal S _{ges is} generated, according to the illustrated first embodiment of the controller 4 activated. By means of the same activation signal S _ges , the switching elements are in a first method step VS1 6.1 to 6.4 the H-bridge circuit 6 as a function of the particular situation switched such that it is in a defined safe state.

In a second method step VS2 is via a bistable flip-flop 11 , a so-called flip-flop, another designed as a power transistor switching element 12 which is between the H-bridge circuit 6 and the power supply 7 is arranged, connected in an electrically non-conductive state, so that the H-bridge circuit 6 from the power supply 7 is disconnected.

Is by means of the activated controller 4 When monitoring found that no fault within the electronic steering lock 2 is present, the switching element 12 in a third method step VS3 by means of the bistable flip-flop 11 closed, leaving the H-bridge circuit 6 with the power supply 7 electrically connected.

If, on the other hand, an error is detected, it is output to a driver of the vehicle, preferably in the interior thereof, on the basis of an optical, acoustic and / or haptic warning.

5 shows a second embodiment of the electronic steering lock 2 , Unlike the in 4 shown first embodiment is when generating the activation signal S _ges and the consequent activation of the controller 4 that on the voltage side of the H-bridge circuit 6 arranged first switching element 6.2 , the so-called first unlocking transistor, and that on the ground side of the H-bridge circuit 6 arranged second switching element 6.3 , the so-called second unlocking transistor, simultaneously switched to an electrically conductive state. This will activate the drive unit 3 safely prevented in the locking direction. At the same time in the permanent voltage branch 7.1 caused an overload reaction, resulting in the triggering of an arranged there electrical security element 13 leads. Thus, the H-bridge circuit is 6 safe from the power supply 7 separated. The security element 13 is for example a fuse.

In 6 is a third embodiment of the electronic steering lock 2 shown. Unlike the in 4 shown first embodiment is when generating the activation signal S _ges and the consequent activation of the controller 4 the other switching element 12 in a second method step VS directly by means of the controller 4 controlled and thus the H-bridge circuit 6 switched off.

7 shows a fourth embodiment of the electronic steering lock 2 , Unlike the in 4 shown first embodiment is when generating the activation signal S _ges and the consequent activation of the controller 4 in a manner not shown, the power supply 7 deactivated and thus the H-bridge circuit 6 switched off.

In 8th is a fifth embodiment of the electronic steering lock 2 shown. Unlike the in 4 shown first embodiment is when generating the activation signal S _ges and the consequent activation of the controller 4 one with the power supply 7 coupled control unit 14 , a s called central control unit, is controlled. The control unit 14 controls the power supply 7 in the way that the electrical supply of the H-bridge circuit 6 is interrupted and thus the H-bridge circuit 6 switched off.

LIST OF REFERENCE NUMBERS

1

comparator circuit

2

steering lock

3

Electric drive unit

4

controller

4.1

interrupt

4.2

Supply voltage connection

4.3

ground connection

5

blocking element

6

H-bridge circuit

6.1 to 6.4

switching element

7

power supply

7.1

Continuous voltage branch

7.2

voltage branch

8th

Ignition lock

9

Limit switches

10

voltage regulators

11

flop

12

switching element

13

security element

14

control unit

BZ

bridge branch

O1, O2

operational amplifiers

D1, D2

diode

e

unlocking

S1, S2

Single signal

S _tot

activation signal

t

Time

U

tension

U _Ant

tension

U _B

operating voltage

U _In

input voltage

R2 to R6

Electrical resistance

U _{ref_high}

reference voltage

U _{ref_low}

reference voltage

V

locking direction

VS1 to VS3

step

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009045224 A1 [0004]

Claims (10)

Electronic steering lock ( 2 ) for a vehicle, comprising - at least one blocking element ( 5 ) for locking the steering, - at least one electric drive unit ( 3 ) for actuating the blocking element ( 5 ) in a locking direction (V) and an unlocking direction (E), - at least one H-bridge circuit ( 6 ) for coupling the electric drive unit ( 3 ) with a power supply ( 7 ) and - at least one controller ( 4 ) for monitoring an operation of the drive unit ( 3 ), characterized in that - a comparator circuit ( 1 ) for comparing a to the electric drive unit ( 3 ) voltage applied to (U _Ant ) with at least one reference voltage (U _{ref_high} , U _{ref_low} ) is provided, - wherein the comparator _circuit ( 1 ) with the controller ( 4 ) is coupled and - in a deviation of the arranged in a bridge branch (BZ) electric drive unit ( 3 ) applied voltage (U _Ant ) of the at least one reference voltage (U _{ref_high} , U _{ref_low} ) by means of the comparator _circuit ( 1 ) an activation signal (S _ges ) for activating the controller ( 4 ) is producible. Electronic steering lock ( 2 ) according to claim 1, characterized in that the comparator circuit ( 1 ) is formed such that the activation signal (S _ges ) in the case of a positive and a negative deviation of the voltage at the electric drive unit ( 3 ) applied voltage (U _Ant ) of the at least one reference voltage (U _{ref_high} , U _{ref_low} ) can be generated. Electronic steering lock ( 2 ) according to claim 1 or 2, characterized in that the comparator circuit ( 1 ) comprises a plurality of operational amplifiers (O1, O2) or is constructed as a flip-flop circuit. Electronic steering lock ( 2 ) according to one of the preceding claims, characterized in that the H-bridge circuit ( 6 ) of two arranged on a voltage side and two arranged on a ground side and H-shaped interconnected switching elements ( 6.1 to 6.4 ), in particular transistors, wherein the bridge branch (BZ) is formed by means of a cross connection, in which the drive unit ( 3 ) is arranged. Method for operating an electronic steering lock ( 2 ) for a vehicle, wherein - by means of at least one, by means of an electric drive unit ( 3 ) actuated blocking element ( 5 ) the steering of the vehicle is locked or unlocked, - by means of at least one H-bridge circuit ( 6 ) the electric drive unit ( 3 ) with a power supply ( 7 ) and - by means of at least one controller ( 4 ) in the activated state, an operation of the drive unit ( 3 ) is monitored, characterized in that - by means of a with the controller ( 4 ) coupled comparator circuit ( 1 ) one on the electric drive unit ( 3 ) applied voltage (U _Ant ) with at least one reference voltage (U _{ref_high} , U _{ref_low} ) is compared and - in a deviation of the at the electric drive unit ( 3 ) applied voltage (U _Ant ) of the at least one reference voltage (U _{ref_high} , U _{ref_low} ) by means of the comparator _circuit ( 1 ) an activation signal (S _ges ) is generated, - by means of which the controller ( 4 ) is activated. Method according to claim 5, characterized in that by means of the controller ( 4 ) in the activated state, the drive unit ( 3 ) and deactivated in case of malfunction. Method according to claim 6, characterized in that by means of the controller ( 4 ) for deactivating the drive unit ( 3 ) the H-bridge circuit ( 6 ) based on a control of a control unit ( 14 ) is de-energized for power distribution. Method according to claim 6, characterized in that by means of the controller ( 4 ) for deactivating the drive unit ( 3 ) on a voltage side of the H-bridge circuit ( 6 ) arranged first unlocking switching element, in particular a first unlocking transistor, and a on a ground side of the H-bridge circuit ( 6 ) arranged second unlocking switching element, in particular a second unlocking transistor, are simultaneously switched to an electrically conductive state. Method according to claim 6, characterized in that by means of the controller ( 4 ) to deactivate the Drive unit ( 3 ) between the H-bridge circuit ( 6 ) and the power supply ( 7 ) arranged switching element ( 12 ), in particular a transistor, is switched to an electrically non-conductive state. A method according to claim 6, characterized in that in the case of a deviation of the electrical drive unit ( 3 ) applied voltage (U _Ant ) of the at least one reference voltage (U _{ref_high} , U _{ref_low} ) by means of the comparator _circuit ( 1 ) a further activation signal is generated, by means of which for deactivating the drive unit ( 3 ) between the H-bridge circuit ( 6 ) and the power supply ( 7 ) arranged switching element ( 12 ), in particular a transistor, is switched to an electrically non-conductive state.

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