DE19758104A1 - Determining absolute rotation angle of motor vehicle steering - Google Patents

Abstract

The method involves using a code device (2) which moves relative to a detector. The code device is detected by a photodetector arrangement (7). A connected segment of the code track is projected on at least one photodetector line, and at least one code word is detected corresponding to a predetermined angle. The position of the code word is measured with respect to the fixed position of the photodetector line. An adaptive absolute angle sensor is also claimed.

Description

The invention relates to a method for absolute determination an angle of rotation according to the preamble of claim 1 as well as an adaptive absolute angle sensor according to the upper concept of claim 11.

EP 0 377 097 B1 describes a steering angle sensor for a Motor vehicle known. This has a steering wheel side arranged ring on the one-track bar code has strips parallel to the steering column. The dispute fencode extends over 360 ° and this is a station  associated sensor arrangement. This shows several times, in Angle spacing arranged sensors. The stripe structure tur forms such a code, which in cooperation with enables the sensors to detect absolute values.

The disadvantage of this arrangement is that a adequate resolution of z. B. 0.8 degrees only with erhebli chem effort is possible because nine sensors in the must have the same angular distance.

The invention is therefore based on the object Determination of the absolute angular position of a rotor, esp special of the steering wheel of a motor vehicle, with less Allow effort.

According to the invention that is according to the features of the claims 1 and 11 reached.

In a method for the absolute determination of a rotation kels, especially for determining the steering angle in one Motor vehicle by means of an angular range of 360 ° attached codes for determining the angle, the code and a detector arrangement relative to one another which are rotatably arranged, the code by means of a a single location photodetector assembly determined and used to determine the angle, and a together dependent segment of the code track is on at least one Mapped photo detector line, with at least one code word is detected, which corresponds to a predetermined angle, and the location of the code word with respect to the fixed position of the Photodetector arrangement is measured.  

For this purpose, the code is chosen so that it covers the total th scope in the viewing area of the photodetector arrangement not repeated. The code is single-track, clear and closed. The method has the advantage that compared to known methods, the angular resolution is not the resolution of the code of the code track and not of the Number of code words but only from the resolution of the Sensors of the photodetector array depends, d. that is, the Angle resolution is independent of the code. Without the use The reference mark depends on the angular resolution of the Number of code words. If at least one code word of Code track would be detected by the photodetector arrangement an angular resolution of one degree for 360 code words.

Because the angular resolution does not depend on the number of code words depends on as few code words as possible the to the sensor sensitivity to environmental influences sen, such as B. pollution. That is z. B. by using 6-bit or 7-bit codes instead reached by 8-bit codes.

The measurement is carried out in software in a microcontroller made the image data of the Photodetector arrangement used.

To further increase the resolution, at least two different images of one or more extent co of the are mapped onto the photodetector arrangement.

The code track can be illuminated with parallel light or be illuminated from one side.  

In a further embodiment of the method, it is provided hen that the code through optics so on the photo detector line is shown that with a readout cycle of Line determines both the absolute angle information as also checked and adjusted the overall function of the system becomes.

At least one Re projected silhouette on the photo detector line become. With contamination in the area of optical Components can then e.g. B. the performance of the light sources can be easily adjusted by increasing the control current. Even the failure of individual detectors from Fotodetek Gate arrangement is noticed and can be calculated were compensated. The reference silhouettes can be cyclical through appropriate software as well as by individually switching on a computer controlled monitoring device are generated.

Furthermore, it is possible for optical compensation and mechanical tolerances, the steepness and Figil size of the signals shown on the detector line be evaluated.

The angular range is within 0 ° to 360 ° over the driving speed of the vehicle determined. To capture the absolute steering angle even when the vehicle system is switched off the steering angle is activated by briefly switching on the steering angle sensor at time intervals when there is no rotation preferably greater than 180 ° is determined.  

The fact that with a single photodetector Angles in the range of 360 ° can be evaluated very quickly can, the system is simply by registering the 360 ° crossing and therefore for several revolutions suitable. In order not only to guarantee this for driving most, the system must be briefly in standby mode be switched on, the switch-on intervals so be selected that no steering wheel rotation in this interval hung greater than 360 ° is possible. Since the system for data transfer has an interface to the vehicle computer from there the vehicle speed is taken over, to define the zero range of the steering angle, because from a certain speed is in normal vehicles no steering angle over z. B. ± 90 ° from the zero position off mobile.

With an adaptive absolute angle sensor, in particular to determine the steering angle in a motor vehicle under Use one on a circular ring over a Winkelbe rich of 360 ° applied codes for the determination of the Angle, the code and a detector arrangement relative are arranged rotatably to each other, min most of all a light source for illuminating an angle area of the code and it is a photo detector Gate arrangement for the detection of the illuminated Winkelbe realm of the code provided, the light source and the A microcontroller is assigned to the photodetector arrangement.

In a first embodiment there are two as the light source light emitting diodes symmetrical to the optical axis arranged, this together with the photodetector on the same side of the annulus are provided.  

In a second embodiment, one is in bright places of the code translucent circular coding ring intended. Furthermore, at least one is emitting light de diode on one side of the coding ring and the photode tector arrangement on the other side of the coding ring orderly. An optic is preferably on the side of the light-emitting diode provided.

To increase the security of the angle sensor and Detection of code errors is in a further embodiment device provided that the photodetector arrangement two Senso ren, which with respect to the course of the code track whose synchronous viewing is arranged vertically one above the other are net and that the images of both sensors together be compared. By comparing the two pictures can local pollution particles (code, optics) as well Sensor errors are recognized. Two can be used as sensors Line sensors or two superimposed sections an area sensor may be provided.

In a further embodiment, two sensors are used synchronous registration of neighboring code words the code track arranged horizontally next to each other.

Charge-coupled are preferably used as photodetectors Elements (CCD) are provided.

The light-dark lines of the code words should be used compared to further decrease in sensor sensitivity Have the largest possible environmental impact. Before the light-dark lines of the code words also indicate a Width of 2 to 3 mm.  

In one embodiment it is provided that between Light source and the transparent coding ring a matt disc is arranged, and that the optics and the photode tector arrangement on the other side of the coding ring are provided.

In a further embodiment, a transparent one Coding ring sections of cylinders lying side by side lenses for generating the code and mapping the light source len on the photodetector array. With this execution an additional look is saved. Through the Cylindrical lenses create stripes of different brightness on the photodetector array.

In a further embodiment it is provided that the Coding ring has a prismatic cross section, wherein a light radiating in the axial direction of the coding ring source is arranged.

In a further embodiment are on a transparent th coding ring in sections lying side by side the or lenses for generating the code and mapping the Light sources arranged on the photodetector arrangement, the cylinders being in the axial direction of the coding ring ges extend and with an end face on the coding ring are attached and assigned to the light sources and with their other, exposed end faces of the Fotodetek gate arrangement are assigned. Through areas with and without Cylinder and design of the density or with and without lenses a code can be applied and detected accordingly become. The exposed end faces of the cylinders are expediently flat or lenticular.  

In one embodiment, the transparent coding ring, the translucent areas and opaque Has areas, at least one point light source assigned. In a first embodiment there are two points shaped light sources next to each other at a constant distance and a single photodetector arrangement is provided. This Arrangement has the advantage that despite the change in radial distance of the coding ring by radial impact the steering wheel or despite changing the distance of the compo ent with each other by mechanical or thermal means flows due to the different shadows of the two light sources, the distance between which remains constant, the Position and angular position of the code on the photodetector arrangement can be precisely detected.

The same advantageous effect can be achieved be that a point light source and two in different distance from the light source one above the other arranged photodetector lines are provided.

In a further embodiment, that the angle-determining code on the coding ring at least one reference code is assigned. The Reference code arranged next to the angle-determining code be, or above and below the angle determining Codes may be provided.

The invention is intended to be used in exemplary embodiments on the basis of Drawings are explained. Show it:

Figure 1 shows the basic structure of a steering angle sensor for performing the method according to the invention in an incident light variant.

FIG. 1a is a plan view of a portion of track code;

FIG. 2 shows the assignment of the photosensitive cells of the CCD line to the voltage amplitudes;

Fig. 3 shows an embodiment of the steering angle sensor, in which in addition a shadow image on a CCD line is projected;

Figure 4 is a plan view of a code with a coarse and a fine range.

Fig. 4a shows a section through the code arrangement with associated optical assemblies.

Fig. 5 is an transmitted light variation of the steering angle sensor;

FIG. 5a is a top view of a portion of track code;

Fig. 6 shows an embodiment of the steering angle sensor with two vertically superimposed CCD lines, to which a code track is assigned;

Fig. 6a is a side view of the embodiment of Fig. 6;

Fig. 7 shows an embodiment of the steering angle sensor with two vertically superimposed CCD lines, each of which a code track is assigned;

Fig. 7a is a side view of the embodiment of Fig. 7;

Fig. 8 shows an embodiment of the steering angle sensor with two horizontally adjacent CCD lines;

Fig. 9 shows an embodiment with injected Codie stanchions in a plastic ring;

FIG. 10a, b, an embodiment of encoding means of cylindrical lenses;

FIG. 11 is a code ring with a prismatic cross-section;

FIG. 12a with a coding ring cylinders;

Fig 12b a coding ring having directly on this angeord Neten lenses.

FIG. 13 is a code ring with a laser diode as a light source;

FIG. 14a, b a coding ring with two laser diodes as a source of light;

FIG. 15a, b a coding ring with a laser diode and two downstream CCD line;

FIG. 16 is the combination of an angle-determining code with an adjacent reference code;

FIG. 17 is the combination of an angle-determining code with it and the underlying Referenzco de;

FIG. 18 is the assignment of the lighting and the CCD line for the combination of Fig. 17;

Fig. 19, the signal generated by the arrangement according to Fig. 19.

A digital, single-track code 2 is attached to the circumference of 360 ° of a rotatable circular ring 1 of a steering device. The code is designed such that it is not repeated over the entire scope in a viewing area 3 . It can be described as single-track, clear and closed. This single-track code is sufficient to determine the absolute steering angle within 360 °.

The viewing area 3 is illuminated by light-emitting diodes 4 and 5 and imaged on a photo detector line 7 via an optical system 6 . This photodetector line is designed as a charge-coupled detector line (CCD line). The code 2 in the viewing area 3 is designed as a black and white code according to FIG. 1a. The code is given as a contrast difference from the photodetector line to a microcontroller 8 . This will differentiate the contrast, decode it and pass the angle of rotation position to the vehicle 10 via an interface 9 .

The entire unit is supplied via a power supply 12 from the 12 volt vehicle network 13 .

To detect the angular position, a coherent segment of the code track, namely the viewing area 3 , is imaged on the photodetector line 7 in this method. Within 0 to 360 °, the absolute steering angle can be clearly determined with a resolution depending on the selected code. The viewing area is selected so that at least one code word 29 ( FIG. 2) of the code track is detected by the CCD line 7 . Each code word corresponds to a steering angle, the angular resolution depending on the number of code words. With 360 code words you have a resolution of one degree. In this way, the Grobwin angle is determined.

With this method, a high resolution, ie a fine angle determination, is achieved regardless of the resolution of the code of the code track and the number of code words. For this purpose, FIG. 2 is a code word of 29 28 measured in the viewing area 3, the position from the beginning 25 and the end 26 relative to a fixed reference mark of the fixed photo detector according to. In this exemplary embodiment, the reference mark is provided at pixel No. 64. The measurement is carried out purely by software in the microcontroller 8 , which uses the image data of the photodetector line 7 for this purpose.

As a result, the position 27 of the code word is obtained with reference to the reference mark 28 of the photodetector line 7 , measured with the resolution of the photodetector. The position or the distance of the code word to the reference mark and thus the angular resolution of the steering angle sensor is therefore only dependent on the resolution with which the photodetector line resolves the viewing area. In the exemplary embodiment, the photodetector line has 128 pixels, with which steering angle resolutions of <0.2 ° can be achieved.

The absolute angle thus consists of the code word and the location of the code word to the photodetector line together.

Since the resolution of the steering angle sensor under the prerequisite that the viewing area 3 detects at least one code word depends only on the resolution of the photodetector line, the light / dark lines of the code word can have large dimensions, for. B. 2-3 mm. It is advisable to use a code with as few code words as possible. That is z. B. by using 6 bit or 7 bit codes instead of z. B. 8 bit codes reached. As a result, the sensor sensitivity to environmental influences, such as. B. pollution.

In Fig. 2 on the x-axis 21, the linear assignment of the photosensitive cells of the CCD line in the viewing area and on the y-axis 22, the associated voltage am plitudes are shown. If the code in the viewing area 3 is mapped very well on the photodetector line 7 , there are very clear contrast differences with correspondingly sharp demarcations. If the image is out of focus due to an excessive radial tolerance or due to contamination, a raw signal of the photodetector line 7 results, the course of which corresponds to the graph 23 . The code is reconstructed by a known curve analysis and evaluation in the microcontroller 8 , so that the signal train 24 is subsequently present. By evaluating the amplitudes as a function of the number of photodetectors in the photodetector line 7 , the gain can be increased or the luminance on the diodes 4 and 5 can be adjusted accordingly in the event of progressive contamination or aging of the components. These settings can also be adjusted via the scope or the area of observation. Axial tolerances are simply compensated for via the height of code track 2 .

To further increase the sensitivity, the steering angle sensor can be further configured according to FIGS . 4 and 4a. The code on a circumference 41 is divided into an upper rough area 42 for recognizing the 0 to 360 ° and into a lower fine area 43 . On the photodetector line 7 is to determine the coarse angle of the coarse Codebe 42 illuminated via a light-emitting diode 45 is imaged by an optics 47 . Subsequently, the fine code area 43 is illuminated by means of a light-emitting diode 46 and a smaller section is imaged on the photodetector line 7 via an optical system 48 . This smaller section can in turn contain a code that covers ± 10 °. Both optics are separated by an aperture 44 . By mapping a smaller section, the resolution and accuracy can be increased accordingly.

Another embodiment of the steering angle sensor is shown in FIG. 3. The arrangement corresponds to that of FIG. 1, however, a monitoring and interface microprocessor 11 is provided for testing the overall system, in which software is installed, which either switch on and / or cyclically switches on one or more light emitting diodes 32 and 33 which are imaged onto the photodetector line 7 via a mask 34 . By sequentially turning on the diodes 32 and 33 , one or more shadow images are successively generated on the photo detector line. The function of the overall arrangement can thus be checked across all components. In the event of contamination in the area of the optical components, z. B. the light output of the light-emitting diodes 4 and 5 can be easily adjusted by increasing the control current accordingly. The failure of individual detectors in the photodetector line is also noticed and can be compensated for by computational measures.

During the entire operating time in which the measurements of the steering angle take place, it is possible not only to diagnose the entire system by evaluating the rise and fall times of the signals according to FIG. 2, the amplitudes of the signals and the mapping of code 2 monitor, but also to compensate for tolerances and to maintain accuracy over almost all operational influences.

While in Fig. 1 an embodiment of the Lenkwin kelsensors is shown that works with incident light, Fig. 5 shows a sensor that works with transmitted light. In this case, a circular ring 54 is translucent in the region of the light lines of a code 53 . A light-emitting diode 52 and an optical system 55 are arranged in the interior of the ring. A photodetector line 51 is assigned to both outside the annulus. The code 53 according to FIG. 5a corresponds to the code of FIG. 1a. In this case, the code track is illuminated with parallel light.

In the embodiment of FIGS. 6 and 6a, two line sensors 65 and 66 are provided, which look at the same code track 62 at different points. Both are arranged vertically with respect to the course of the code track and capture the viewing area 63 synchronously but at different positions 67 , 68 .

By comparing the two images, local dirt particles, e.g. B. on the code or the optics, and sensor errors can be detected. Instead of two single-line sensors 65 and 66 , an area sensor 61 can also be used for this function.

In the exemplary embodiment of FIGS. 7 and 7a, a code 73 with two tracks 71 , 72 is provided, as can be seen from FIG. 7a. Each of the two code tracks is viewed with a line sensor 65 , 66 or different lines of an area sensor 61 . The code of the second Co despur can now z. B. be inverse to that of the first code track, so that simple subtraction of the measured values in the microcontroller 8 results in simple control of the sensor inputs.

Another arrangement is shown in FIG. 8. To increase the sensor safety, a second CCD sensor 85 is placed horizontally next to the first CCD sensor 84 in this embodiment. Due to the horizontal arrangement, different code words are registered at two different locations on the code track 82 . The difference in the measurement results of both CCD sensors must result in the difference viewing angle of both photodetectors to the code track. This angle is known due to the position of the CCD sensors.

Instead of a second CCD sensor, a correspondingly larger linear CCD sensor can also be used. Furthermore, the combination of two photodetector lines in an integrated circuit 81 with a common housing is possible.

In the exemplary embodiment in FIG. 9, one or more LEDs 86 are imaged directly on a photodetector arrangement 89 or via a focusing screen 87 via optics 88 . The coding consists of a ring 90 , in which translucent angular areas 91 and opaque angular areas 92 are generated by injected recesses or by correspondingly translucent and opaque plastics.

In the embodiment of Fig. 10a and b one or more LED's are imaged 86 directly or through the ground glass screen 87 or the Fresnel lens by means of an array of similar or differently shaped cylindrical lenses 93 without further optics on the photodetector array 89th The cylindrical lenses 93 produce stripes of different brightness on the photodetector arrangement 89 . By appropriate arrangement and distribution of the cylindrical lenses 93 on the dierring 94 made of a transparent medium, a corresponding code is generated which is used to scan the steering angle. The arrangement of the cylinder lenses is shown in Fig. 10b.

Instead of mapping the LEDs onto a ground glass as in FIGS . 9 and 10, a coding ring 95 can be made so that it consists of a prismatic arrangement in which one or more LEDs 86 z. B. axially irradiate the arrangement ( Fig. 11). The light rays are deflected at the hypotenuse 95 a of the prism. The radial light emission on the circumference of the coding ring 95 is designed in such a way that quasi-planar surface areas 96 and cylindrical lens arrangements 93 are located there. The flat surfaces create a homogeneous light emission onto the radially attached photodetector arrangement 89 . The cylinder lenses 93 produce 89 areas of low and high luminance on the photodetector arrangement. The coding for steering angle determination is carried out by appropriate distribution of the quasi-planar surfaces and by the same or differently designed cylindrical lenses.

In a further embodiment according to FIG. 12a, light is radiated in the axial direction via LEDs 86 in a transparent coding ring 97 and this coding ring has a number of cylinders 98 which are connected directly to the coding ring at one end and at the other end are either flat or lenticular. A corresponding luminance will thus occur at each of these cylinders, which can be detected via the photodetector arrangement 89 . Areas can be applied to areas with and without cylinders and the density can be designed and detected accordingly. A variant of this embodiment is shown in FIG. 12b, in which lenses 99 are provided directly on the coding ring 97 instead of the cylinder 98 . The effect corresponds to that of the arrangement with cylinders described above.

In addition to the embodiments shown in the figures, the serve as an example for the embodiment according to the invention, can arrange the arrangements in radial or axial form tet, the direction of light passage in two possible directions can be selected.

In the embodiment of FIG. 13, no lens arrangement is required. An almost punctiform light source, e.g. B. by using a laser diode 101 with a light centering surface of z. B. 2µ × 3µ with the barrier layer z. B. parallel to the axis illuminates the coding ring 90 , which consists of the translucent areas 91 and the translucent areas 92 . Behind the coding ring 90 , a linear photodetector arrangement 89 is provided, on which a luminance distribution is produced by the coding in the translucent areas. This luminance distribution is evaluated.

The arrangement according to FIG. 13 can be improved by using two laser diodes 101 and 102 arranged next to one another and at a known distance, as is shown in FIGS. 14a and b. The evaluation is carried out as described in the embodiment of FIG. 13. However, the radial distance of the coding ring 90 changes due to radial impact of the steering wheel or changes due to mechanical or thermal influences the distance between the components, which is indicated in Fig. 14a by items 1 and 2 of the photodetector arrangement, so by the different shadow formation of the two laser diodes 101 and 102 , the distance between which remains constant, the position and angular position of the code can nevertheless be detected precisely on the photodetector arrangement 89 . The laser diodes 101 and 102 can be excited quickly in succession, the time being chosen to be so short, e.g. B. 10 microseconds-100 microseconds that during this time there is no restriction on the angle change on the steering wheel. Instead of the laser diodes, it is of course also possible to use a monolithic LED in a double or triple arrangement, in which light-emitting surfaces with a very small extent in the axial direction are generated by appropriate masks.

The same effect is also achieved by using a single laser diode 101 or LED when the shadow image is formed on two photodetector lines 103 and 104 which are attached at different distances from the code ring 90 (FIGS . 15a and 15b). The code can be determined precisely through the ratios of the shadow structure. Due to the absolute extent of the code on the photo detector lines, the distance of the code ring in the event of an axial stroke is determined.

The embodiment in FIG. 16 shows a combination of an angle-determining code 105 with a reference code de 106 . By projecting the code over a length that at least covers the angle code and the reference code, both the angle can be evaluated and the CCD or the photodetector arrangement can be checked on the one hand, and the distance and the other on the known distances of the reference code the exact angle can be determined.

The angle-determining code 105 can also be applied parallel to the reference code 106 , as is shown in FIG. 17. If the reference code 106 , as shown here, is applied at the top and bottom at the edge of the angle encodings, then an axial tolerance does not affect the mapping of the reference code 106 .

Both codes can be mapped together and illuminated by means of LEDs 86 , as can be seen in FIG. 18. An angle signal 107 and reference signal 108 corresponding to FIG. 19 can thus be generated and evaluated on the photodetector arrangement 89 .

Claims (30)

1. A method for absolute determination of an angle of rotation, in particular for determining the steering angle in a motor vehicle by means of a code applied over an angle range of 360 ° for determining the angle, the code and a detector arrangement being arranged rotatably relative to one another, characterized in that that the code is determined by means of a photodetector arrangement attached at a single point and is used for angle determination that a coherent segment of the code track is mapped onto at least one photodetector line, at least one code word being detected which corresponds to a predetermined angle, and that Location of the Codewor tes measured with respect to the fixed position of the photodetector line. 2. The method according to claim 1, characterized in that that the measurement software in a microcon troller is made, this the image data the photo detector line used.   3. The method according to claim 1 or 2, characterized records that to increase the resolution at least two different images of one or more rer range codes on the photodetector line be det. 4. Method according to at least one of the preceding Claims, characterized in that a 6-bit or 7-bit code word is used. 5. Method according to at least one of the preceding Claims, characterized in that the code track Illuminated with parallel light or by one Side is illuminated. 6. Method according to at least one of the preceding Claims, characterized in that the code Abge optics on the photodetector line is that with a read cycle of the line both the absolute angle information is determined as also checked the overall function of the system and is adjusted. 7. Method according to at least one of the preceding Claims, characterized in that for monitoring system functions at least one reference Silhouette projected onto the photo detector line becomes.   8. The method according to at least one of the preceding Claims, characterized in that for the Compensation of optical and mechanical tolerances Slope and image size of the on the Mapped signals evaluated detector line become. 9. The method according to at least one of the preceding Claims, characterized in that the Winkelbe range within 0 ° to 360 ° above the driving speed vehicle is determined. 10. The method according to at least one of the preceding Claims, characterized in that for Detection of the absolute steering angle also at switched off vehicle systems the steering angle by briefly turning on the steering angle sensor in Time intervals in which no rotation greater than 180 ° is possible is determined. 11. Adaptive absolute angle sensor, in particular for determining the steering angle in a motor vehicle, using a code attached to a circular ring over an angular range of 360 ° for determining the angle, the code and a detector arrangement being arranged rotatably relative to one another, in particular for Implementation of the method according to at least one of procedural claims 1 to 10, characterized in that at least one light source ( 4 , 5 ) is provided for illuminating an angular region ( 3 ) of the code ( 2 ), and in that a photodetector arrangement ( 7 ) is provided for the detection of the illuminated angular range ( 3 ) of the code ( 2 ), the light source and the photo detector arrangement being assigned a microcontroller ( 8 ). 12. Adaptive absolute angle sensor according to claim 11, characterized in that two light-emitting diodes ( 4 , 5 ) are arranged symmetrically to the optical axis as the light source, these together with the photodetector arrangement ( 7 ) and optics ( 6 ) on the same side of the Coding ring ( 1 ) are arranged. 13. Adaptive absolute angle sensor according to claim 11, characterized in that a translucent at bright spots of the code circular coding ring ( 54 ) is provided that at least one light-emitting diode ( 52 ) on one side of the Co dierringes and the photodetector arrangement ( 51 ) the other side of the coding ring is arranged. 14. Adaptive absolute angle sensor according to claim 13, characterized in that an optical system ( 55 ) is provided on the side of the light-emitting diode ( 52 ). 15. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that the photodetector arrangement has two sensors ( 65 , 66 ) which are arranged vertically one above the other with respect to the course of the code track ( 62 ) for their synchronous viewing and that the images ( 67 , 68 ) of the two sensors are compared. 16. Adaptive absolute angle sensor according to claim 15, characterized in that as sensors two line sensors ( 65 , 66 ) or two superimposed sections of a surface sensor ( 61 ) are hen vorgese. 17. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that two sensors ( 84 , 85 ) for the synchronous registration of adjacent code words of the code track ( 82 ) are arranged horizontally next to one another. 18. Adaptive absolute angle sensor after at least one of the preceding claims, characterized records that charge-coupled as photodetectors Elements (CCD) are provided.   19. Adaptive absolute angle sensor after at least one of the preceding claims, characterized draws the light-dark lines of the code words have a width of 2 to 3 mm. 20. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that between the light source ( 86 ) and the coding ring ( 90 ) a matt screen ( 87 ) is arranged, and that the optics ( 88 ) and the photodetector arrangement ( 89 ) the other side of the coding ring ( 90 ) are provided. 21. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that a transparent coding ring ( 94 ) sectionally adjacent cylinder lenses for generating the code and imaging the light sources ( 86 ) on the photodetector arrangement ( 89 ). 22. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that the coding ring ( 95 ) has a prismatic cross section, wherein a light source ( 86 ) radiating in the axial direction of the coding ring is arranged. 23. Adaptive absolute angle sensor according to at least one of claims 11 to 21, characterized in that sections of cylinders ( 98 ) or lenses ( 99 ) lying side by side on a transparent coding ring ( 97 ) for generating the code and imaging the light sources ( 86 ) the photodetector arrangement ( 89 ) are provided, the cylinders extending in the axial direction of the coding ring and being fastened with one end face to the coding ring and being assigned to the light sources and with their other, the end face of the photodetector arrangement ( 89 ) being exposed. 24. Adaptive absolute angle sensor according to claim 23, characterized in that the exposed The faces of the cylinders are flat or lens-shaped are trained. 25. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that the transparent coding ring ( 90 ), the translucent areas ( 91 ) and opaque areas ( 92 ), at least one point light source ( 101 , 102 ) is assigned. 26. Adaptive absolute angle sensor according to claim 25, characterized in that two point-shaped light sources ( 101 , 102 ) side by side at a constant distance and a single photo detector arrangement ( 89 ) are provided. 27. Adaptive absolute angle sensor according to claim 25, characterized in that a punctiform light source ( 101 ) and two at different distances from the light source ( 101 ) one above the other photo detector lines ( 103 , 104 ) are provided. 28. Adaptive absolute angle sensor according to at least one of the preceding claims, characterized in that at least one reference code ( 106 ) is assigned to the angle-determining code ( 105 ) on the coding ring. 29. Adaptive absolute angle sensor according to claim 28, characterized in that the reference code ( 106 ) is arranged next to the angle-determining code ( 105 ). 30. Adaptive absolute angle sensor according to claim 28, characterized in that the reference code ( 106 ) is provided above and below the angle-determining code ( 105 ).