DE102016103601B4 - SINGLE FAULT TOLERANT ELECTRIC STEERING SYSTEM - Google Patents

Abstract

Device for controlling an electric motor (12) of a steering system comprising: first phases (U1, V1, W1), second phases (U2, V2, W2), a first output stage (8) and a first control module (6) and a second output stage (9) and a second control module (7), wherein the first output stage (8) and the first control module (6) are provided for controlling the first phases (U1, V1, W1) and the second output stage (9) and the second control module (7) are provided for controlling the second phases (U2, V2, W2), and wherein the first control module (6) is a microcontroller or a microcomputer and the second control module (7) is a microcontroller or a microcomputer, characterized in that in the event that there is a fault in a first control circuit, in a first control line or in the first phases (U1, V1, W1), the first control module (6) and the first output stage (8) are separated from the electric motor (12) and the electric motor (12) is controlled by the second control module (7) and the second output stage (9), in particular to maintain steering assistance, and/orthat in the event that there is a fault in a second control circuit, in a second control train or in the second phases (U2, V2, W2), the second control module (7) and the second output stage (9) are separated from the electric motor (12) by a second isolating switch (11) and the electric motor (12) is controlled by the first control module (6) and the first output stage (8), in particular to maintain steering assistance.

Description

FIELD OF INVENTION

The present invention relates to a device for controlling an electric motor of a steering system and a steering system of a vehicle.

BACKGROUND OF THE INVENTION

Redundant controls for highly automated driving are known in the state of the art.

Furthermore, the EN 10 2012 101 006 A1 a device for controlling an electric motor of a steering system comprising first phases, second phases, a first output stage and a first FET driver, a second output stage and a second FET driver and a single control module designed as a microcontroller, wherein the control module is provided to control the first phases by means of the first output stage and the first FET driver and the second phases by means of the second output stage and the second FET driver.

In addition, the EN 10 2015 214 473 A1 a device for controlling an electric motor of a steering system comprising first phases in the form of a first winding group, second phases in the form of a second winding group and a controller which can have a first output stage, a second output stage and a single control unit.

In addition, the EN 10 2014 113 105 A1 a generic power steering device with an electric motor comprising first phases and second phases and with a motor control device which comprises a first output stage assigned to the first phases and a first controller assigned to the first phases as well as a second output stage assigned to the second phases and a second controller assigned to the second phases.

SUMMARY OF THE INVENTION

Highly automated driving means that a vehicle can be driven safely without a human driver. The prerequisite for this is that the vehicle can be driven safely or brought into a safe state even in the event of a malfunction. This results in fault-tolerant driving. The steering of a vehicle in particular is a critical element here. One means of meeting the requirements for safe, highly automated driving is the redundant design of the vehicle components. However, when designing the steering in particular, it must be taken into account that a redundant design can require a large amount of installation space, which is sometimes not available. Ways must therefore be found that achieve fault-tolerant behavior through redundancy, while the necessary installation space for the steering remains appropriate.

One task is therefore to provide a device that enables steering for a vehicle for highly automated driving, whereby the installation space required can be kept small.

This object is achieved by a device according to claim 1 and a steering according to claim 7.

As a first embodiment of the invention, a device for controlling an electric motor of a steering system is provided, comprising: first phases and two phases, wherein the device comprises a first output stage and a first control module and a second output stage and a second control module, wherein the first output stage and the first control module are provided for controlling the first phases and the second output stage and the second control module are provided for controlling the second phases.

The separate phases allow redundancy to be achieved with just one motor. This enables highly automated driving while still keeping the dimensions of the steering system small.

As a second embodiment of the invention, a steering system of a vehicle is provided, comprising a device according to one of the preceding claims.

Exemplary embodiments are described in the dependent claims.

According to an exemplary embodiment of the invention, a device is provided, the device comprising a first voltage supply and a second voltage supply, the first voltage supply being provided for the first control module and the second voltage supply being provided for the second control module.

Redundancy can be further increased by redundant power supplies for the control modules.

In a further embodiment of the invention, a device is provided, wherein the device comprises a first control channel for transmitting control signals and a second control channel for transmitting control signals, wherein the first control channel is provided for the first control module and the second control channel is provided for the second control module.

Separate control channels for information transmission can increase the redundancy of the device according to the invention.

In this case, the control component is a microcontroller or a microcomputer.

According to an exemplary embodiment of the invention, a device is provided, wherein the device is suitable for highly automated driving.

According to a further embodiment of the present invention, a device is provided, wherein the electric motor has first phases and/or second phases and/or third phases and/or fourth phases and/or fifth phases and/or any number of phases.

One idea of the invention can be seen as providing an electric motor that has a plurality of sets of phases. This allows a redundant design of the steering in question and at the same time the structural mass of the steering can be kept small.

The individual features can of course also be combined with one another within the scope of the claims, which can sometimes result in advantageous effects that go beyond the sum of the individual effects.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 eine aus dem Stand der Technik bekannte Ansteuerung eines 3-phasigen Elektromotors eines Lenksystems eines Fahrzeugs,
• 2 eine Ansteuerung eines 6-phasigen Elektromotors eines Lenksystems eines Fahrzeugs, der zum hochautomatisierten Fahren geeignet ist, und
• 3 eine alternative Ausführungsform einer Ansteuerung eines 6-phasigen Elektromotors eines Lenksystems eines Fahrzeugs, der zum hochautomatisierten Fahren geeignet ist.

Further details and advantages of the invention will become clear from the embodiments shown in the drawings. They show:

• 1 a control of a 3-phase electric motor of a steering system of a vehicle known from the prior art,
• 2 a control of a 6-phase electric motor of a steering system of a vehicle that is suitable for highly automated driving, and
• 3 an alternative embodiment of a control of a 6-phase electric motor of a steering system of a vehicle that is suitable for highly automated driving.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows a non-inventive control of a 3-phase electric motor of a steering system with a microcontroller 1, which is supplied with electrical energy and control signals through a channel 5. The microcontroller 1 generates control signals that are necessary for the correct functioning of the output stage 2. If a fault occurs, the phases U, V, W of the 3-phase motor 4 can be released by isolating switch 3. This allows the vehicle to be steered. However, in this case the vehicle must be steered without the steering assistance of the motor 4.

2 shows the control of a 6-phase electric motor 12. Here, 3 related phases U1, V1, W1 and U2, V2, W2 can be controlled by separate control lines. The first 3 phases U1, V1, W1 of the motor 12 are controlled by a first microcontroller 6 and a first output stage 8. In the event of a fault, the motor 12 can be disconnected by a disconnector 10.

If there is a fault in the first control line, the first microcontroller 6 and the first output stage 8 can be separated from the motor 12 by the isolating switch 10. So that steering assistance can be provided by the motor 12 even in the event of a fault, the motor 12 is controlled by a second microcontroller 7 and a second output stage 9. In the event of a fault, the second phases U2, V2, W2 of the motor 12 can be released by the isolating switch 11. The microcontrollers 6 and 7 are supplied with electrical energy and control signals via a common channel 13. The embodiment is suitable for highly automated driving because the redundant design ensures fault-tolerant behavior of the steering assistance. In particular, fault-tolerant behavior can be achieved on the basis of an electric motor that has several related phases U1, V1, W1 and V2, U2, W2. What is important here is the redundant control of at least two groups of three phases of an electric motor. If a fault occurs in a control circuit or a group of three phases, this control circuit can be isolated by a disconnector and another group of three phases is controlled by another control circuit. Fault-tolerant behavior is enabled, while uninterrupted steering assistance is possible.

3 shows an alternative embodiment of the fault-tolerant steering support, whereby the microcontrollers 6 and 7 are supplied with electrical energy and control signals through separately formed channels 14, 15. Due to the redundant design of the control and/or energy supply of the microcontrollers 6, 7, the faulty The tolerant behavior of the steering assistance can be further improved.

It should be noted that the term “comprising” does not exclude further elements or method steps, just as the terms “a” and “an” do not exclude multiple elements and steps.

The reference symbols used serve only to increase comprehensibility and should in no way be considered as limiting, the scope of the invention being reflected in the claims.

LIST OF REFERENCE SIGNS

1

Microcontroller

2

Power amplifier

3

Disconnector

4

Motor, 3-phase

5

Power supply and control signals

6

Microcontroller 1

7

Microcontroller 2

8th

Power amplifier 1

9

Power amplifier 2

10

Disconnector 1

11

Disconnector 2

12

Motor, 6-phase

13

Power supply and control signals

14

Power supply and control signals

15

Power supply and control signals

Claims (7)

Device for controlling an electric motor (12) of a steering system, comprising: first phases (U1, V1, W1), second phases (U2, V2, W2), a first output stage (8) and a first control module (6) and a second output stage (9) and a second control module (7), wherein the first output stage (8) and the first control module (6) are provided for controlling the first phases (U1, V1, W1) and the second output stage (9) and the second control module (7) are provided for controlling the second phases (U2, V2, W2), and wherein the first control module (6) is a microcontroller or a microcomputer and the second control module (7) is a microcontroller or a microcomputer, characterized in that in the event that there is a fault in a first control circuit, in a first control line or in the first phases (U1, V1, W1), the first control module (6) and the first output stage (8) are are separated from the electric motor (12) and the electric motor (12) is controlled by the second control module (7) and the second output stage (9), in particular for maintaining steering assistance, and/or that in the event that there is a fault in a second control circuit, in a second control train or in the second phases (U2, V2, W2), the second control module (7) and the second output stage (9) are separated from the electric motor (12) by a second isolating switch (11) and the electric motor (12) is controlled by the first control module (6) and the first output stage (8), in particular for maintaining steering assistance. Device according to Claim 1 , characterized in that the device comprises a first voltage supply and a second voltage supply, wherein the first voltage supply is provided for the first control module (6) and the second voltage supply for the second control module (7). Device according to one of the Claims 1 or 2 , characterized in that the device has a first control channel (14) for transmitting control signals and a second control channel (15) for transmitting control signals, wherein the first control channel (14) is provided for the first control module (6) and the second control channel (15) is provided for the second control module (7). Device according to one of the preceding claims, characterized in that the first control module (6) is supplied with electrical energy and control signals through a first control channel (14) and the second control module (7) is supplied with electrical energy and control signals through a second control channel (15) or the control modules (6, 7) are supplied with electrical energy and control signals through a common channel (13). Device according to one of the preceding claims, characterized in that the first phases (U1, V1, W1) and the second phases (U2, V2, W2) can each be controlled by separate control strands. Device according to one of the preceding claims, characterized in that the electric motor has first phases (U1, V1, W1) and/or second phases (U2, V2, W2) and/or third phases and/or fourth phases and/or fifth phases and/or any number of phases. Steering of a vehicle comprising a device according to one of the preceding claims.

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