ELONGATE BODY COMPRISING A CURSOR BAND FOR A VEHICLE SYSTEM OF A VEHICLE

Abstract

An elongate body for a vehicle system of a vehicle, the body having at least one cursor band for an inductive linear displacement sensor, the at least one cursor band extending in the direction of a longitudinal extent of the body, the at least one cursor band being designed with a plurality of electrically conductive cursor pads in order to inductively couple at least one excitation coil to at least one sensor coil of a stator of the linear displacement sensor and being designed with non-coupling sections which are electrically less conductive or non-conductive with respect to the cursor pads, the cursor pads being spaced apart from one another in the direction of the longitudinal extent in each case by the non-coupling sections, and the cursor pads of the cursor band being formed on the body.

Claims

1. An elongate body for a vehicle system of a vehicle, the elongate body comprising: at least one cursor band for an inductive linear displacement sensor, the at least one cursor band extending in a direction of a longitudinal extent of the body, the at least one cursor band being designed with a plurality of electrically conductive cursor pads in order to inductively couple at least one excitation coil to at least one sensor coil of a stator of the linear displacement sensor and being designed with non-coupling sections which are electrically less conductive or non-conductive with respect to the cursor pads, the cursor pads being spaced apart from one another in the direction of the longitudinal extent by the non-coupling sections, and the cursor pads of the cursor band being formed on the elongate body.

2. The body according to claim 1, wherein the body has at least two cursor bands, the cursor pads of the two cursor bands being arranged offset from one another in the direction of the longitudinal extent of the cursor bands.

3. The body according to claim 2, wherein the at least two cursor bands are arranged on opposite or adjacent sides of the body.

4. The body according to claim 2, wherein the at least two cursor bands each have a different number of cursor pads.

5. The body according to claim 1, wherein the cursor pads are formed as elevations of the body or on elevations of the body which are elevated relative to the non-coupling sections.

6. The body according to claim 5, wherein a cross section of the elevations has a mushroom shape.

7. The body according to claim 5, wherein the elevations are flattened on a top side facing away from the body.

8. The body according to claim 1, wherein the non-coupling sections are formed by grooves between the cursor pads.

9. The body according to claim 1, wherein the cursor pads of the cursor band are integrally bonded to the body.

10. The body according to claim 1, wherein the body and the at least one cursor band are formed in one piece.

11. The body according to claim 1, wherein the body is formed of a support material or of a plastic, to which the cursor pads are applied in the form of conductive platelets and/or conductive coatings.

12. The body according to claim 1, wherein the body is formed as a steering actuator rod, a piston rod, or a rail.

13. A vehicle system assembly comprising: the elongate body according to claim 1; and an inductive linear displacement sensor, wherein the linear displacement sensor has a stator with the at least one excitation coil and the at least one sensor coil as well as an evaluation circuit, wherein the evaluation circuit is configured to detect a linear position of the body based on the at least one cursor band relative to the stator as a function of the inductive coupling between the at least one excitation coil and the at least one sensor coil.

14. A steering system comprising a vehicle system assembly according to claim 13, wherein the steering system is designed as a steer-by-wire system with a control unit and an electromechanical actuator, wherein the control unit is coupled to the linear displacement sensor and is set up to convert the position, detected by the linear displacement sensor, of the body, which is designed as a steering actuator rod, into a steering command for the electromechanical actuator and to transmit it to the electromechanical actuator so that the electromechanical actuator executes a steering movement corresponding to the steering command.

15. A vehicle comprising a vehicle system assembly according to claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0044] FIG. 1 shows a perspective view of a steering actuator rod;

[0045] FIG. 2 shows a cross section of the steering actuator rod of FIG. 1;

[0046] FIG. 3 shows an alternative cross section of the steering actuator rod of FIG. 1;

[0047] FIG. 4 shows a cross section of a steering assembly with the steering actuator rod of FIG. 1;

[0048] FIG. 5 shows a view of a signal-linear path diagram of the sensor coils in the inductive linear displacement sensor of FIG. 4;

[0049] FIG. 6 shows a principal view of a steering system of a vehicle; and

[0050] FIG. 7 shows a principal view of a steering unit of the steering system of FIG. 6.

DETAILED DESCRIPTION

[0051] FIG. 1 shows a steering actuator rod 12 in a perspective view. Steering actuator rod 12 is shown here only in an excerpt or with a partial length of the true length of steering actuator rod 12, which can be significantly longer, as can be gathered in principle from FIG. 7, for example. Steering actuator rod 12 extends along a longitudinal axis L.

[0052] Thus, steering actuator rod 12 shown and described herein is merely an exemplary embodiment of an elongate body 12 of the invention. Alternatively, elongate body 12 can be formed, for example, as a piston rod of a shock absorber or a seat rail of a vehicle seat in the vehicle. In this respect, what is shown and described in the context of FIGS. 1 to 7 with respect to the embodiment of elongate body 12 applies analogously to the generic embodiment as an elongate body 12 in a vehicle system of a vehicle as well as to specific embodiments.

[0053] A cursor, which in the present case is formed by two cursor bands 4.1, 4.2, is formed on a part, in particular at or near one end, of steering actuator rod 12. Here, from the perspective shown, only cursor band 4.1 is fully visible, whereas cursor band 4.2 opposite cursor band 4.1 is concealed by steering actuator rod 12 or its rod body. However, the two cursor bands 4.1, 4.2 are basically constructed with the same elements.

[0054] Cursor band 4.1 has linearly cyclically spaced cursor pads 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, wherein one of the plurality of non-coupling sections 6.1, 6.2, 6.3, 6.4, 6.5 is disposed between each two cursor pads 5. Cursor pads 5 serve as inductive coupling regions for stators 2.1, 2.2 with their sensor coil sets 3.1, 3.2, as can be seen in FIG. 4 and explained in more detail later with reference to FIG. 4. Here, the coil sets comprise one to n individual receiver coils each. For the widely used CIPOS® technology, these are three individual receiver coils per receiver coil set.

[0055] In the present case, steering actuator rod 12 with cursor pads 5 is formed in one piece from an electrically conductive material, in particular from a metallic material. For this purpose, steering actuator rod 12 with the area of cursor pads 5 and non-coupling sections 6 can be cut, for example, from a cast or deep-drawn cylindrical rod.

[0056] In principle, the number of cursor pads 5 and non-coupling sections 6 can be freely selected according to the respective requirement, in particular the linear path to be measured in the process. Thus, for example, the number of cursor pads 5 can be between 3 and 30, especially between 5 and 20. Similarly, the number of non-coupling sections 6 can be between 2 and 29, in particular between 4 and 19.

[0057] The non-coupling sections 6 can be formed by a material less electrically conductive than cursor pads 5 or a non-electrically conductive material. In particular, they can be formed by an insulator between cursor pads 5. In the present case, however, non-coupling sections 6 are formed in a simplified manner by grooves in cursor bands 4.1, 4.2 between two cursor pads 5 each of each cursor band 4.1, 4.2, which form free spaces between cursor pads 5. This is a particularly preferred embodiment variant of non-coupling sections 6 because the cursor can be manufactured easily and inexpensively thereby, and good measurement results can be achieved. In particular, because cursor pads 5 project beyond the grooves or groove surfaces of the grooves in the form of elevations 7 (see FIG. 2), in particular elevations 7 which are mushroom-shaped in cross section, no additional insulator needs to be used.

[0058] FIG. 2, in a cross section of steering actuator rod 12, shows elevations 7.1, 7.2 that form the opposite cursor pads 5.1, 5.2. The opposite cursor pads 5.1, 5.2 have a mushroom shape or T-shape with a stem or column 20.1, 20.2, respectively, each extending away from steering actuator rod 12. On column 20.1, 20.2 there is in each case a platform 21.1, 21.2 or a plate-shaped element which extends over the underlying surface of steering actuator rod 12, in particular extends parallel to it. Platforms 21.1, 21.2 are preferably, but not necessarily, flattened or provided with a flat surface on their top sides 23.1, 23.2. Outer edges 24.1, 24.2 located transversely to the extent of steering actuator rod 12 and opposite one another in this transverse direction are beveled. Columns 20.1, 20.2 are formed by slits 22.1, 22.2, 22.3, 22.4 between steering actuator rod 12 or its rod-shaped body and platforms 21.1, 21.2. In other words, due to each of slits 22.1, 22.2, 22.3, 22.4, there is a free space between platforms 21.1, 21.2 and the body of steering actuator rod 12.

[0059] FIG. 3 shows an alternative embodiment for forming the entire steering actuator rod 12 in a one-piece design from a metallic material. In the present case, steering actuator rod 12 and elevations 7.1, 7.2 are made from a support or core of, for example, plastic. In this case, the support or core can be produced inexpensively in an injection molding process. Cursor pads 5.1, 5.2 are then applied by gluing or some other arrangement on elevations 7.1, 7.2, as shown here.

[0060] FIG. 4 shows a steering assembly 50 as an exemplary embodiment of a vehicle system assembly 50, in which an inductive linear displacement sensor 1 is formed by steering actuator rod 12 of FIG. 1 or cursor bands 4.1, 4.2 located thereon and stators 2.1, 2.2. Alternatively, a mutual stator 2 can also be used.

[0061] Linear displacement sensor 1 is designed to determine the linear position and/or the linear path of the cursor covered in a direction of movement X with cursor bands 4.1, 4.2 relative to stators 2.1, 2.2. Stators 2.1, 2.2 each have an excitation coil 9.1, 9.2 and a sensor coil set 3.1, 3.2, which are arranged in a manner known to the skilled artisan on or in the respective stator 2.1, 2.2, which in the present case is formed by printed circuit boards. The two sensor coil sets 3.1, 3.2 are each assigned to one of cursor bands 4.1, 4.2 or are arranged parallel to them.

[0062] Cursor pads 5, which are adjacent to one another and transverse to the longitudinal extent of cursor bands 4.1, 4.2, are arranged with an offset V to one another. This is shown, by way of example, by cursor pads 5.1, 5.7, between which the offset V is marked. In other words, cursor pads 5 of the respective cursor bands 4.1, 4.2 are each attached at different lengths or positions of steering actuator rod 12 when considered in terms of the extent. In addition, cursor band 4.2 has fewer cursor pads 5 than cursor band 4.1, in the present case, for example, five cursor pads 5 in cursor band 4.2 and six cursor pads 5 in cursor band 4.1.

[0063] In the present case, cursor pads 5 and non-coupling sections 6 have a rectangular shape. Although this is easy to implement in terms of production technology, it is not necessary for the function in cursor bands 4.1, 4.2. Thus, for example, it is alternatively possible to form cursor pads 5 and/or non-coupling sections 6 with a rectangular shape with rounded corners, with an elliptical shape, or with some other shape.

[0064] Stators 2.1, 2.2 are located at a distance from cursor bands 4.1, 4.2 and parallel thereto. In addition, stators 2.1, 2.2 have a common evaluation circuit 8 or individual evaluation circuits 8.1, 8.2 in each case, which can, however, be interconnected or work together. Evaluation circuit 8 is set up to determine the relative position of the cursor of steering actuator rod 12 or a covered linear path relative to stators 2.1, 2.2 as a function of the inductive coupling between excitation coils 9.1, 9.2 and the two sensor coil sets 3.1, 3.2 of stators 2.1, 2.2 by means of the cursor in an operating state of inductive linear displacement sensor 1 according to the present exemplary embodiment, therefore, when inductive linear displacement sensor 1 is turned on. From the linear position of steering actuator rod 12 relative to stators 2.1, 2.2 determined in this way, the linear position, linear path, and/or linear speed of steering actuator rod 12 relative to stators 2.1, 2.2 can then be determined in a manner known to the skilled artisan by means of evaluation circuit 8.

[0065] Depending on the linear location or linear position of steering actuator rod 12 relative to stators 2.1, 2.2, one or more cursor pads 5 of cursor bands 4.1, 4.2 are operatively connected to the respective excitation coils 9.1, 9.2 and sensor coil sets 3.1, 3.2. Non-coupling sections 6 located between cursor pads 5 are substantially not operatively connected to excitation coils 9.1, 9.2 and sensor coil sets 3.1, 3.2. Cursor pads 5 thus establish an inductive coupling of excitation coils 9.1, 9.2 with sensor coil sets 3.1, 3.2, respectively, which ensures a unique combination of output signals of sensor coil sets 3.1, 3.2, as can be gathered from FIG. 4.

[0066] FIG. 5 shows the signal strength S in % of the output signals 31, 32 of sensor coil sets 3.1, 3.2 generated as triangular signals over the covered linear path X in the direction of motion X. These output signals 31, 32 are passed to evaluation circuit 8 for evaluation. Output signals 31, 32 of sensor coils 3.1, 3.2 are combined by evaluation circuit 8 to form a resulting signal 30, which gives the linear path X covered.

[0067] Cursor bands 4.1, 4.2 form different nonius tracks with a different number of cursor pads 5 with corresponding non-coupling sections 6, wherein cursor pads 5 and non-coupling sections 6 of the two cursor bands 4.1, 4.2 are designed and arranged relative to each other such that an evaluation of the relative position of the movable part to stators 2.1, 2.2 is made possible by means of evaluation circuit 8 in the manner of the nonius principle.

[0068] Now, in vehicle system 10, in the present example in the form of steering system 10, in vehicle 100 as shown in FIGS. 6 and 7, stator 2 or stators 2.1, 2.2 can be attached to an immovable or non-movable part. When steering actuator rod 12 is moved, the cursor also moves with it, namely, past stators 2.1, 2.2. In a manner known to the skilled artisan, excitation coils 9.1, 9.2 provide excitation or eddy current generation in cursor pads 5, which in turn are each detected by sensor coil sets 3.1, 3.2. As a result, evaluation circuit 8 can measure a linear path of the movement of the cursor in the direction of movement X or a linear position, therefore, a position in the linear direction of movement X, of the cursor relative to the corresponding linear position of stators 2.1, 2.2 according to the nonius principle with cursor bands 4.1, 4.2 having cursor pads 5 which are offset relative to one another and differ in number. The linear position or linear path of steering actuator rod 12 or rack can be inferred from this.

[0069] FIG. 6 shows a steering system 10 of a vehicle in the form of an automobile, which is designed in the form of a steer-by-wire system.

[0070] In so-called steer-by-wire systems, in which the steering column is omitted, the system is provided first by a man-machine interface and second by a positioning device on the wheels of the vehicle. The first-mentioned unit is located in the vehicle interior and preferably includes a steering wheel with steering angle sensor technology and a reset device. The second-mentioned positioning device is connected to the preferably two front wheels and is formed by a position control loop with a target value and an actual value. As is common in a position control loop, control takes place in digital form using a position control algorithm in a microprocessor or other digital control or a hardwired algorithm in a so-called state machine. In principle, however, analog controls or analog/digital hybrid controls are also conceivable for the control task.

[0071] In order to be able to carry out the control precisely, the position sensor is of great importance. In principle, angle sensors or linear displacement sensors can be considered as position sensors. The embodiment chosen here provides linear displacement sensor 1 of FIG. 1 on steering actuator rod 12 of steering system 10 (see FIG. 7).

[0072] Steering system 10 comprises a steering element 11, which in the present case is designed as a steering wheel. The driver of vehicle 100 wishes to steer the vehicle by means of steering element 11, and for this purpose turns the steering wheel in a certain direction by a certain steering angle. This steering angle and the steering torque are captured by a sensor system installed on the steering wheel. To be precise, a control unit 15 (also known as an electronic control unit, or ECU for short) of steering system 10 is electronically connected to the corresponding sensor system and receives the driver's steering request (steering angle and steering torque) and forwards it to a power unit 13, which is in turn connected to control unit 15 and is often referred to as a power pack.

[0073] The steering is based on a position control loop with a target value and an actual value. By means of inductive linear displacement sensor 1 in power unit 13 (see FIG. 7), the actual position of the wheels of the vehicle can be determined. Steering actuator 16 (see FIG. 7), also in power unit 13, is then controlled by control unit 15 to actuate the steering according to the driver's request. This is done by moving steering actuator rod 12 linearly to the right or left, and thereby moving the wheels of vehicle 100 accordingly. This continues until linear displacement sensor 1 informs control unit 15 that the target position, which control unit 15 has specified according to the driver's steering wheel actuation, has been reached.

[0074] FIG. 7 shows a more detailed schematic diagram of steering system 10, which also shows the components of power unit 13. Linear displacement sensor 1 is located with stator 2 (which can be formed by multiple stators 2.1, 2.2) on a housing 14 of power unit 13, wherein cursor bands 4.1, 4.2 are fastened to steering actuator rod 12 and are arranged to be movable relative to stator 2. For example, housing 14 can include a recess or pocket in which stator 2 or stators 2.1, 2.2 can be embedded.

[0075] The otherwise necessary and costly cabling is eliminated by the integration of linear displacement sensor 1 into power unit 13, because the cabling existing in power unit 13 can be used or advantageously expanded. In addition, the interfaces and the supply lines of the electronics on stators 2.1, 2.2 of linear displacement sensor 1 do not need be protected against short circuits of the supply lines and output lines of linear displacement sensor 1. This usually allows simplified electronics and a simpler and more cost-effective manufacturing process for the semiconductor technologies used. Due to a more compact design of this embodiment, the overall arrangement is also less sensitive to electromagnetic radiation from interference fields, by which an increase in the operational robustness of the sensor technology is achieved.

[0076] The operating principle of steering unit 10, as described above, is such that control unit 15 of steering system 10 within power unit 13 receives the driver's steering request when the driver of vehicle 100 actuates steering element 11. Control unit 15 can then use the linear position or linear path of steering actuator rod 12, which it obtains or can calculate from the measurements of linear displacement sensor 1, to actuate the electromechanical actuator or steering actuator 16 to control the steering of vehicle 100 in accordance with the steering request expressed by the driver by actuating steering element 11.

[0077] Actuator 16 is actuated until the target position according to the driver's steering request is reached. This is the case when the control difference E=actual position—target position is zero. The actual position in turn emerges from the measurements of linear displacement sensor 1.

[0078] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.