Motor vehicle with a sensor device for a steering device of the motor vehicle

Abstract

Motor vehicle with a sensor device for a steering device of the motor vehicle, wherein the sensor device comprises: - multiple steering angle sensors (21-24); - at least one first and one second evaluation unit (101, 201) for evaluating signals from the steering angle sensors (21-24), wherein - the first evaluation unit (101) is connected to several of the steering angle sensors (21-24) or to all of the steering angle sensors (21-24) in order to receive and evaluate signals from these steering angle sensors (21-24), and wherein - the second evaluation unit (201) is connected to at least one of the steering angle sensors (21-24) in order to receive and evaluate signals from this at least one steering angle sensor (23), wherein - the first evaluation unit (101) is connected to a larger number of steering angle sensors (21-24) than the second evaluation unit (201), characterized in that - the first evaluation unit (101) together with some of the steering angle sensors (21, 22, 24) with which it is connected, forms a first steering angle sensor unit (20) or belongs to a first steering angle sensor unit (10), and - the second evaluation unit (201) together with some or all of the steering angle sensors (23) with which it is connected, forms a second steering angle sensor unit (20) or belongs to a second steering angle sensor unit (20), wherein - the first steering angle sensor unit (10) is arranged in or on a steering handle of the motor vehicle such that it moves with the steering handle when a steering angle is entered, while the second steering angle sensor unit (20) is located away from the steering handle and fixed to the vehicle, or conversely, the second steering angle sensor unit (20) is arranged in or on the steering handle of the motor vehicle such that it moves with the steering handle when a steering angle is entered, while the first steering angle sensor unit (10) is located away from the steering handle and fixed to the vehicle, wherein - the first and second steering angle sensor units (10, 20) are connected to each other via a contact unit (30), and wherein - the first evaluation unit (101) of the first steering angle sensor unit (10) is connected via an electrical winding band of the contact unit (30) to at least one steering angle sensor (23) of the second steering angle sensor unit (20).

Description

[0001] The invention relates to a motor vehicle with a sensor device for a steering device of the motor vehicle according to the preamble of claim 1.

[0002] In the context of electric power steering systems (steer-by-wire systems), it is known from the state of the art to use three steering angle sensors to detect the steering angle, whose signals are evaluated by two evaluation units. Each of the two evaluation units receives the signals from the three sensors, with the signals from two of the sensors being used to determine the steering angle (the "2-out-of-3 voting" principle).

[0003] A receiver implemented by the vehicle's electronics receives the results from both evaluation units. The receiver detects any discrepancies between the results and (depending, for example, on status information sent from the evaluation unit in question) either uses only one of the received results, i.e. operation occurs despite a sensor fault, or none of the results are used, i.e. a sensor failure is detected. With the known solutions, however, there is a risk, for example, that a fault in one of the evaluation units could impair the function of other components, such as the other evaluation unit. There is also the risk of simultaneous damage to several electrical connections between the steering angle sensors and the evaluation units ("common cause faults").

[0004] The generic document DE 10 2014 220 781 A1 discloses a system with a first and second processing unit, each of which has an interface for communicating with a sensor and an actuator. Furthermore, DE 198 34 870 A1 describes an electromechanical steering actuator divided into two redundant systems. Furthermore, DE 10 2009 054 106 A1 discloses a device for acquiring data in a redundant system with at least two safety paths.

[0005] The problem underlying the invention is to enable the most reliable detection of a steering angle possible.

[0006] This problem is solved by providing a motor vehicle with a sensor device having the features of claim 1. Further developments of the invention are specified in the dependent claims.

[0007] Thereafter, a motor vehicle is provided with a sensor device for a steering device of a motor vehicle, the sensor device comprising: - several steering angle sensors; - at least one first and one second evaluation unit for evaluating signals from the steering angle sensors, - wherein the first evaluation unit is connected to several of the steering angle sensors or to all of the steering angle sensors in order to receive and evaluate signals from these steering angle sensors; - and wherein the second evaluation unit is connected to at least one of the steering angle sensors in order to receive and evaluate signals from this at least one steering angle sensor, wherein - the first evaluation unit is connected to a larger number of steering angle sensors than the second evaluation unit.

[0008] The second evaluation unit serves primarily as a backup evaluation unit, whose output signals (results) are used in the event of a failure of the first evaluation unit. The second evaluation unit is connected to fewer sensors than the first evaluation unit, thereby reducing the number and complexity of the required connections (communication connections) between the steering angle sensors and the evaluation units, and thus the susceptibility to errors of the sensor device. The reduced number and complexity of the connections, in particular, reduces the risk of common-cause errors.

[0009] For example, the sensor device according to the invention comprises at least three (particularly redundant) steering angle sensors, with the first evaluation unit being connected to the three steering angle sensors. It is possible for the second evaluation unit to be connected to only one of the three steering angle sensors and accordingly receive and evaluate signals from only one of the three steering angle sensors.

[0010] According to the invention, the first evaluation unit, together with some of the steering angle sensors with which it is connected, forms a first steering angle sensor unit or is part of such a first steering angle sensor unit. For example, the first evaluation unit and the steering angle sensors forming the first steering angle sensor unit are housed in a common housing or arranged together in a corresponding receptacle of the vehicle or a vehicle component. It is also conceivable for the first evaluation unit and at least some of the steering angle sensors to be arranged on a common electrical circuit board.

[0011] Analogously, the second evaluation unit, together with some or all of the steering angle sensors with which it is connected, forms a second steering angle sensor unit or belongs to such a second steering angle sensor unit.

[0012] The first and second steering angle sensor units are, in particular, redundant units, with the first steering angle sensor unit acting, for example, as the main unit, while the second steering angle sensor unit provides a backup unit. In particular, only the first steering angle sensor unit, i.e., the first evaluation unit, evaluates the signals (information) from multiple steering angle sensors, while the second steering angle sensor unit (i.e., the second evaluation unit) only evaluates information from a single steering angle sensor. For example, the first evaluation unit of the first steering angle sensor unit performs a plausibility check, according to which signals from only some of the steering angle sensors connected to it are used to determine a steering angle; for example, in the manner of the 2-out-of-3 plausibility check mentioned above.

[0013] By dividing the system into a main and a backup steering angle sensor unit, only the first evaluation unit needs to evaluate signals from multiple (especially three) sensors (in particular, compare them with each other). The second evaluation unit or the second steering angle sensor unit, on the other hand, can be designed to be less powerful. Furthermore, it is conceivable that only one steering angle sensor, namely the steering angle sensor of the second steering angle sensor unit serving as the backup steering angle sensor unit, has two mutually isolated and non-reactive outputs. Furthermore, a redundant power supply for the second steering angle sensor unit could be dispensed with. Furthermore, it is conceivable that there is only a minimal coupling between the first and second evaluation units, namely only via a single steering angle sensor that is connected to both the first and the second evaluation unit.This enables, in particular, a spatially separated arrangement of the steering angle sensor units, which can reduce the risk of common-cause errors.

[0014] The steering angle sensors (e.g., three) connected to the first evaluation unit are arranged and configured in such a way that, even if one of these steering angle sensors fails, absolute steering angles greater than 360° can be determined from a combination of information from the other, non-failing steering angle sensors. In particular, even with the signals from just two of the sensors, multiple rotations of the steering wheel or steering column can be determined.

[0015] The first steering angle sensor unit is arranged in or on a steering handle of the motor vehicle such that it moves with the movement of the steering handle during the input of a steering angle, while the second steering angle sensor unit is arranged remotely from the steering handle and fixed to the vehicle. The second steering angle sensor unit therefore does not move with the movement of the steering handle. The steering handle is, in particular, a steering wheel with a rim that can be rotated around a steering wheel hub to allow a user to input a steering angle.

[0016] Alternatively, conversely, the second steering angle sensor unit is arranged in or on a steering handle of the motor vehicle in such a way that it moves with a movement of the steering handle during the input of a steering angle, while the first steering angle sensor unit is arranged remotely from the steering handle and fixed to the vehicle (for example on or in a dashboard of the vehicle).

[0017] According to the invention, the first and second steering angle sensor units are connected to one another via a contact unit; thus, the contact unit comprises a wound conductor strip in a manner known per se. The evaluation unit of the first steering angle sensor unit is connected to at least one steering angle sensor of the second steering angle sensor unit via the contact unit. It is particularly conceivable that only a small number of electrical connections are implemented via the contact unit. For example, as already mentioned above, the contact unit is designed as only a single connection between the evaluation unit of the first steering angle sensor unit and the sensor (or one of the sensors) of the second steering angle sensor unit.

[0018] Furthermore, the first and second steering angle sensor units (in particular the first and second evaluation units) can be galvanically isolated from one another. It is conceivable that a communication connection nevertheless exists between the steering angle sensor units, for example via an optical and / or magnetic communication connection. In particular, it is possible for the galvanic isolation to exist despite a connection between the first and second steering angle sensor units via the above-mentioned contact unit; for example, by there being a partial electrical connection between components of the sensor device (e.g. the first evaluation unit and a steering angle sensor) via a winding tape, whereby this electrical connection does not exist continuously between the components, but is partially replaced by an optical and / or magnetic connection.

[0019] The first and / or second steering angle sensor unit can furthermore each have at least one dedicated power supply (e.g., a dedicated voltage source) and / or a dedicated communication interface (in particular to a communication bus of the vehicle). It is also conceivable for the first and / or second steering angle sensor unit to have multiple redundant power supplies and / or communication interfaces to increase the availability of the steering angle information.

[0020] It is also possible for the first and / or the second steering angle sensor unit to have an energy storage device (for example in the form of a follow-up buffer) for supplying voltage to the respective evaluation unit and / or at least some of the respective sensors. The energy storage device is, for example, a capacitor or a battery. In particular, the energy storage device can be switched on if all voltage supplies to a steering angle sensor unit fail simultaneously. This can ensure that a steering angle signal is available, at least for a limited time. It is also possible for the steering angle sensor units to have a modular design and the energy storage device can be added as needed. For example, the steering angle sensor unit and the energy storage device have corresponding electrical interfaces. The energy storage device is activated, in particular, by means of an energy source (e.g.the sensor device) or several, in particular redundant, energy sources.

[0021] It is also possible for the first steering angle sensor unit to comprise at least two evaluation units, each of which is connected to several (in particular at least three) steering angle sensors and evaluates their signals. Such a sensor device is, for example, still functional at least temporarily even if two independent faults occur simultaneously.

[0022] The invention is explained in more detail below using exemplary embodiments with reference to the figures. They show: Fig. 1 is a block diagram of a sensor device according to a first embodiment of the invention; Fig. 2 is a block diagram of a sensor device according to a second embodiment of the invention; and Fig. 3 a block diagram of a sensor device according to a third embodiment of the invention.

[0023] The Fig. The sensor device 100 according to the invention for a steering device of a motor vehicle, shown in Figure 1, comprises a first and a second steering angle sensor unit 10, 20, wherein the first steering angle sensor unit 10 comprises a first evaluation unit 101 and the second steering angle sensor unit 20 comprises a second evaluation unit 201. The evaluation units 101, 201 each serve to evaluate (electrical) signals from a plurality (three) of steering angle sensors 21-23. The steering angle sensors 21-23 each detect a steering angle, in particular a steering position of a steering wheel of the vehicle or an angular position of a steering column. The steering angle sensors 21-23 are in particular redundant, i.e. they serve to detect the same steering angle. However, it is conceivable that the steering angle sensors 21-23 operate at least partially according to different measuring principles.

[0024] Two of the steering angle sensors (steering angle sensors 21 and 22), together with the first evaluation unit 101, are part of the first steering angle sensor unit 10, while the third steering angle sensor 23, together with the second evaluation unit 201, is part of the second steering angle sensor unit 20. The steering angle sensor units 10, 20 are spatially separated from one another, i.e., arranged at a distance from one another. More precisely, the first steering angle sensor unit 10 is arranged in or on a steering wheel or another movable, in particular rotatable, component of a steering system of the vehicle, while the second steering angle sensor unit 20 is fixedly mounted on the vehicle. However, the first and second steering angle sensor units 10, 20 are in communication with one another via a contact unit 30, in particular via an electrical winding strip 31 of the contact unit 30.

[0025] Via the contact unit 30, in particular, a connection 230 is established between the third steering angle sensor 23 belonging to the second steering angle sensor unit 20 and the first evaluation unit 101 of the first steering angle sensor unit 10. The first evaluation unit 101 is thus connected not only to the two steering angle sensors 21, 22, but also to the third steering angle sensor 23 in order to be able to evaluate signals from the three steering angle sensors 21-23. The second evaluation unit 201, on the other hand, is only connected to the third sensor 23 belonging to the second steering angle sensor unit 20 and thus only evaluates signals from this one sensor. The second steering angle sensor unit 20 represents, in particular, a reserve unit, wherein the results of the second evaluation unit 201 regarding a determined steering angle are used, in particular, only in the event of a failure of the first steering angle sensor unit 10.As part of the reserve unit, the second evaluation unit 201 is connected to fewer steering angle sensors than the first evaluation unit 101 of the first steering angle sensor unit 10.

[0026] The two steering angle sensor units 10, 20 further comprise separate, redundant power supplies 102, 202 for supplying power to the respective evaluation units 101, 201 and steering angle sensors 21-23. The power supplies 102, 202 are each separately connected to an on-board electrical system 301, 302 of the vehicle. Furthermore, the steering angle sensor units 10, 20 include separate, redundant communication interfaces 103, 203. The communication interfaces 103, 203 of the two steering angle sensor units 10, 20 are connected to (in particular, different) data buses 401, 402 of the vehicle.

[0027] The communication connection 230 between the first evaluation unit 101 and the first steering angle sensor unit 10, via which, in particular, data or other electrical signals from the sensor 23 are transmitted to the first evaluation unit 101, is designed in particular such that a galvanic separation of the two steering angle sensor units 10, 20 exists. For example, a galvanic connection between the first evaluation unit 101 and the sensor 23 is interrupted and replaced by an optical and / or magnetic communication link (e.g., upstream or downstream of the contact unit 30 or its winding tape 31).

[0028] Fig. 2 concerns a modification of the Fig. 1. Conversely, the second steering angle sensor unit 20, ie the reserve unit, is arranged in or on a steering wheel or other movable, in particular rotatable, component of a steering system of the vehicle, while the first steering angle sensor unit 20, ie the main unit, is mounted fixedly on the vehicle.

[0029] In Fig. 3 shows another embodiment of the sensor device 100 according to the invention. According to this embodiment, the first steering angle sensor unit 10 comprises, in addition to the first evaluation unit 101, a further, redundant evaluation unit 104 and a further steering angle sensor 24. The two evaluation units 101, 104 of the first steering angle sensor unit 10 are each connected to all three steering angle sensors 21, 22, 24 of the first steering angle sensor unit 10 and thus each receive the signals from these three sensors. The two evaluation units 101, 104 of the first steering angle sensor unit 10 each apply, in particular, the "2-out-of-3 voting" already mentioned at the beginning, i.e., the signals from two of the three sensors 21, 22, 24 are used, and a result (in particular a steering angle) is determined and output therefrom (e.g., transmitted to vehicle electronics).

[0030] The evaluation units 101, 104 of the first steering angle sensor unit 10 each have their own power supply 102, 105, which are each connected to one of the two on-board networks 301, 302, as well as their own communication interfaces 103, 106, each with a connection to the vehicle data bus 401 or 402.

[0031] The second steering angle sensor unit 20 has, in contrast to the Fig. 1 and Fig. 2 has two (redundant) power supplies 202, 204 and two communication interfaces 203, 205. Furthermore, the second steering angle sensor unit 20 comprises an energy storage device 5 (capacitor or battery), which can be connected to these components (via switches 51-53) as needed to supply power to the steering angle sensor 23 and / or the evaluation unit 201. Depending on the position of the switches 51-53, the energy storage device 5 is also charged using the power supplies 202, 204. The energy storage device 5 is, however, optional. A modular design of the energy storage device 5 and the second steering angle sensor unit 20 is also conceivable, wherein the energy storage device 5 is only connected to the second steering angle sensor unit 20 when needed, for example.

[0032] According to Fig.3, the second steering angle sensor unit 20 is arranged in or on a steering wheel or other movable, in particular rotatable, component of a steering system of the vehicle, while the first steering angle sensor unit 10 is mounted fixedly to the vehicle. Of course, the reverse case would also be conceivable, with the second steering angle sensor unit 20 being fixedly mounted to the vehicle and the first steering angle sensor unit 10 being movable.

Claims

[1] Motor vehicle with a sensor device for a steering device of the motor vehicle, the sensor device comprising: - several steering angle sensors (21-24); - at least one first and one second evaluation unit (101, 201) for evaluating signals from the steering angle sensors (21-24), wherein - the first evaluation unit (101) is connected to several of the steering angle sensors (21-24) or to all of the steering angle sensors (21-24) in order to receive and evaluate signals from these steering angle sensors (21-24), and wherein - the second evaluation unit (201) is connected to at least one of the steering angle sensors (21-24) in order to receive and evaluate signals from this at least one steering angle sensor (23), wherein - the first evaluation unit (101) is connected to a larger number of steering angle sensors (21-24) than the second evaluation unit (201), characterized by , that - the first evaluation unit (101) together with some of the steering angle sensors (21, 22, 24) with which it is connected forms a first steering angle sensor unit (20) or belongs to a first steering angle sensor unit (10), and - the second evaluation unit (201) together with some or all of the steering angle sensors (23) with which it is connected forms a second steering angle sensor unit (20) or belongs to a second steering angle sensor unit (20), wherein - the first steering angle sensor unit (10) is arranged in or on a steering handle of the motor vehicle in such a way that it moves along with a movement of the steering handle during the input of a steering angle, while the second steering angle sensor unit (20) is arranged remotely from the steering handle and fixed to the vehicle, or conversely, the second steering angle sensor unit (20) is arranged in or on the steering handle of the motor vehicle in such a way that it moves along with a movement of the steering handle during the input of a steering angle, while the first steering angle sensor unit (10) is arranged remotely from the steering handle and fixed to the vehicle, wherein - the first and second steering angle sensor units (10, 20) are connected to one another via a contact unit (30), and wherein - the first evaluation unit (101) of the first steering angle sensor unit (10) is connected to at least one steering angle sensor (23) of the second steering angle sensor unit (20) via an electrical winding tape of the contact unit (30). [2] Motor vehicle according to claim 1, characterized by that the sensor device has at least three steering angle sensors (21-24), wherein the first evaluation unit (101) is connected to the three steering angle sensors (21-24). [3] Motor vehicle according to claim 2, characterized by that the second evaluation unit (201) is only connected to one of the steering angle sensors (23). [4] Motor vehicle according to one of the preceding claims, characterized by that the first and second steering angle sensor units (10, 20) are galvanically separated from each other. [5] Motor vehicle according to claim 4, characterized bythat the connection between the first and the second steering angle sensor unit (10, 20) comprises an optical and / or magnetic connection. [6] Motor vehicle according to one of the preceding claims, characterized by that the first and / or the second steering angle sensor unit (10, 20) each have at least one independent voltage supply (102, 105, 202, 204) and / or one communication interface (103, 106, 203, 205). [7] Motor vehicle according to one of the preceding claims, characterized by that the first and / or the second steering angle sensor unit (10, 20) comprises an energy store (5) for supplying voltage to the respective evaluation unit (101, 201) and / or at least some of the respective steering angle sensors (21-24). [8] Motor vehicle according to one of the preceding claims, characterized by that the first steering angle sensor unit (10) comprises at least two evaluation units (101, 104). [9] Motor vehicle according to one of the preceding claims, characterized by that the steering angle sensors (21-24) connected to the first evaluation unit (101) are arranged and designed in such a way that even if one of these steering angle sensors (21-24) fails, absolute steering angles greater than 360° can be determined from a combination of information from the other steering angle sensors that have not failed.

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