JP2010256232A - Rotation angle detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation angle detection device which can suppress malfunction of a control system caused by erroneous assembly into a rotator or the like. <P>SOLUTION: The rotation angle detection device can detect a steering angle of a steering wheel in terms of an absolute angle and a relative angle, and outputs a signal showing a detected absolute angle and a signal showing a detected relative angle to each control device 30, 31. In this case, necessary angle information showing which of the relative angle and the absolute angle is required by each control device 30, 31 is stored beforehand in memories 30a, 31a of each control device 30, 31. It is determined based on the necessary angle information which of the relative angle and the absolute angle of the steering wheel is required by each control device 30, 31, and it is determined based on the determination result which signal between the signal showing the relative angle and the signal showing the absolute angle is to be output to each control device 30, 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device capable of detecting a rotation angle of a rotating body to be detected by a relative angle and an absolute angle.

  2. Description of the Related Art In recent years, a skid prevention system that automatically performs engine output control, brake control of each wheel, and the like to suppress a skid of a vehicle is well known. This skid prevention system determines whether the vehicle is skidding based on the yaw rate of the vehicle or the steering angle of the steering wheel, and performs control to reduce the engine output based on the judgment result. The system usually requires a device for detecting the steering angle of the steering wheel. In addition to such a skid prevention system, for example, various on-vehicle control systems such as a BGM (Back Guide Monitor) system that assists the driver in retreating the vehicle by displaying the expected course when the vehicle retreats on the display are also used for the steering wheel. A device for detecting the steering angle is necessary. Conventionally, as a rotation angle detection device for detecting the steering angle of such a steering wheel, for example, rotation angle detection devices described in Patent Documents 1 and 2 are known.

  The rotation angle detection device described in Patent Document 1 has a main gear that rotates integrally with a steering shaft that is a rotation shaft of a steering wheel of a vehicle, and one detection gear is engaged with the main gear. Further, in this apparatus, a magnet is provided in the detection gear, and a magnetic detection unit that outputs a voltage signal corresponding to the direction of the magnetic field emitted from the magnet is arranged in a manner facing the magnet. Incidentally, the magnetic detection unit is configured by a magnetoresistive element whose resistance value changes due to the magnetoresistive effect according to the direction of the applied magnetic field. That is, in this device, when the detection gear rotates with the rotation of the main gear, the voltage signal output from the magnetic detection unit changes. In this apparatus, the required calculation processing is performed based on the output value of the output signal of the magnetic detection unit and its period, so that the rotation angle of the main gear is a relative angle, in other words, the steering angle of the steering wheel is a relative angle. Detect with. Note that the relative angle of the steering wheel indicates the rotation angle by the amount of change from a certain reference point when the steering wheel rotates, and does not correspond one-to-one with the steering angle of the steering wheel from the straight traveling state of the vehicle. Is an angle. For example, as shown by a solid line in FIG. 7, the relative angle of the steering wheel is set to “60 °” as one cycle with respect to a change in the rotation angle of the steering wheel from a certain position “0 °”. , And an angle within 60 ° and the number of periods.

  And in the said vehicle-mounted control system, the relative angle of a steering wheel is detectable by taking in the signal (relative angle signal) which shows the relative angle output from this rotation angle detection apparatus. Further, in the on-vehicle control system, for example, the number of cycles of the relative angle signal is counted, and the steering angle from the predetermined reference position of the steering wheel based on the count value and the relative angle of the steering wheel, that is, the steering wheel. It is also possible to detect the absolute angle.

  On the other hand, the rotation angle detection device described in Patent Document 2 has a main gear and a detection gear as in the rotation angle detection device described in Patent Document 1, but has two detection gears having different numbers of teeth. Are different in that they mesh with the main gear. In addition, in this apparatus, magnets are provided in the two detection gears, respectively, and magnetic detection units that output voltage signals corresponding to the direction of the magnetic field emitted from the magnets are arranged in a manner opposed to the magnets. Has been. Incidentally, these magnetic detectors are also composed of magnetoresistive elements whose resistance values change due to the magnetoresistive effect according to the direction of the applied magnetic field. In this device, the rotation angle of each detection gear is calculated based on the output signal of each magnetic detection unit, and the required calculation processing is performed using the difference value of the calculated rotation angle, thereby the steering wheel. The steering angle is detected as an absolute angle, and a signal corresponding to the detected absolute angle (absolute angle signal) is output to the in-vehicle control system. The absolute angle of the steering wheel is an angle corresponding to the steering angle of the steering wheel on a one-to-one basis as described above and as shown by the two-dot chain line in FIG.

  And in the said vehicle-mounted control system, the absolute angle of a steering wheel is directly detectable by taking in the absolute angle signal output from this rotation angle detection apparatus. For this reason, in the said vehicle-mounted control system, since it is not necessary to perform various arithmetic processing in order to detect the absolute angle of a steering wheel, it becomes possible to reduce the calculation burden of the system.

JP 2004-239670 A JP 2007-127609 A

  By the way, in the rotation angle detection device that detects the absolute angle of the steering wheel, the detection range is set in advance depending on the number of teeth of the main gear and the detection gear. Therefore, it is necessary to accurately match the reference position of the steering wheel and the predetermined reference position of the steering wheel. However, if the reference position of the rotation angle detector is misaligned to the vehicle, the angle exceeding the detection range of the device is detected when the steering wheel is rotated by the driver. There is a possibility that so-called overflow of the output signal that the output signal deviates from an appropriate value occurs. When such an overflow of the output signal occurs, the in-vehicle control system may erroneously detect the steering angle of the steering wheel, which may cause malfunction of the system. Incidentally, such a problem of overflow of the output signal does not occur in the rotation angle detection device that detects the relative angle of the steering wheel. Therefore, from the viewpoint of overflow of the output signal, considering the redundancy when mounting the sensor, it is more advantageous to perform various controls using relative angle signals than to perform various controls using absolute angle signals. I can say that.

  On the other hand, in-vehicle control systems such as the above-mentioned skid prevention system and BGM system, some systems require the relative angle of the steering wheel to execute various controls related to the system, and the absolute angle of the steering wheel is required. There is also a system. Specifically, the system that requires the relative angle of the steering wheel includes, for example, the above-mentioned skid prevention system, and the system that requires the absolute angle of the steering wheel includes, for example, the above-mentioned BGM system.

  Here, among the skid prevention systems, for example, in the system that calculates the absolute angle from the relative angle of the steering wheel described above, even if the signal output from the rotation angle detection device is an absolute angle signal, Thus, it is possible to detect the absolute angle of the steering wheel without any special arithmetic processing. Therefore, in such a skid prevention system, there is no practical problem even if an absolute angle signal is output instead of the relative angle signal.

  For this reason, even if the vehicle is equipped with both the skid prevention system and the BGM system, or the vehicle equipped with either the skid prevention system or the BGM system, the steering wheel By mounting a rotation angle detection device that detects the absolute angle of the vehicle on the vehicle, standardization as a vehicle has been attempted. That is, an absolute angle signal is output to all systems.

  However, if such a configuration is adopted, if the absolute angle signal overflows due to, for example, incorrect assembly of the rotation angle detection device described above to the vehicle, all in-vehicle systems may malfunction. There is. That is, in a skid prevention system that requires the relative angle of the steering wheel, if the input signal is a relative angle signal, the skid prevention system may malfunction even though the overflow problem did not originally occur. There is.

  Such a problem is not limited to a vehicle on which a skid prevention system or a BGM system is mounted, but may similarly occur on a vehicle on which various control systems that require the absolute angle and relative angle of the steering wheel are mounted. Further, the present invention is not limited to the rotation angle detection device for detecting the steering angle of the steering wheel, and may be generated in the same manner as long as the rotation angle detection device detects the rotation angle of a predetermined rotating body.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a rotation angle detection device that can suppress malfunction of a control system due to erroneous assembly to a rotating body.

  In order to solve the above problem, the invention according to claim 1 is capable of detecting the rotation angle of the rotating body to be detected by a relative angle and an absolute angle, and a signal indicating the detected relative angle. And a rotation angle detection device that outputs a signal indicating an absolute angle to a control system that executes various controls based on the rotation angle of the rotating body, whether the control system requires the relative angle or the absolute angle. The gist is to determine whether to output a signal indicating the relative angle or a signal indicating the absolute angle to the control system based on the determination result.

  According to this configuration, a control system that requires the absolute angle of the rotating body requires a relative angle of the rotating body while ensuring proper operation of the system by outputting a signal indicating the absolute angle. A signal indicating the relative angle can be output to the control system. If a signal indicating the relative angle is output to the control system that requires the relative angle of the rotating body in this way, an abnormal situation occurs in which the rotational angle detecting device is erroneously assembled to the rotating body. However, an overflow does not occur in the signal input to the control system that requires the relative angle of the rotating body. Therefore, since it becomes possible to ensure the proper operation of the control system that requires at least the relative angle of the rotating body, the malfunction of the control system can be suppressed.

  According to a second aspect of the present invention, in the rotation angle detecting device according to the first aspect, the control system stores in advance necessary angle information indicating which of the relative angle and the absolute angle is necessary. In determining whether the control system requires the relative angle or the absolute angle, the control system obtains the necessary angle information from the control system, and the control system uses the relative angle information to obtain the relative angle. The gist is to determine which of the angle and the absolute angle is required.

  According to this configuration, the rotation angle detection device can detect which of the relative angle and the absolute angle only by storing the necessary angle information indicating whether the relative angle or the absolute angle is necessary in the control system. You will be able to judge what you need. For this reason, the structure for judging whether the control system requires a relative angle or an absolute angle can be easily realized.

  According to a third aspect of the present invention, in the rotation angle detecting device according to the first or second aspect, when it is detected that at least one system that requires the absolute angle exists in the control system, A signal indicating the absolute angle is output to all of the control systems, and when it is detected that all of the control systems are systems that require the relative angle, the relative angle is displayed to all of the control systems. The gist is to output a signal.

  As described above, by outputting a signal indicating the relative angle to the control system that requires the relative angle of the rotating body, at least the control system that requires the relative angle of the rotating body performs the proper operation. It will be possible to secure. However, for example, a control system that requires the relative angle of the rotating body outputs a signal indicating the relative angle, and a control system that requires the absolute angle of the rotating body outputs a signal indicating the absolute angle. However, if an overflow occurs in the signal indicating the absolute angle, the control system that requires the absolute angle of the rotating body will eventually malfunction. If a control system that requires the absolute angle of the rotating body malfunctions in this way, there is a risk of hindering normal operation of the entire control system. Therefore, as described above, when there is at least one control system that requires the absolute angle of the rotating body in the control system, a signal indicating the absolute angle is given to all of the control systems, and the control system When all of the control systems require a relative angle of the rotating body, an effect of ensuring the normal operation of the entire control system by outputting a signal indicating the relative angle to all of the control systems. Can get enough.

  According to the rotation angle detection device of the present invention, it is possible to suppress malfunction of the control system due to erroneous assembly to the rotating body.

The top view which shows the schematic structure about one Embodiment of the rotation angle detection apparatus concerning this embodiment. Sectional drawing which shows the cross-sectional structure along the II-II line | wire of FIG. The block diagram which shows the system structure about the rotation angle detection apparatus of the embodiment. The wave form diagram which shows the example of a waveform of the relative angle signal output from the rotation angle detection apparatus of the embodiment. The wave form diagram which shows the example of a waveform of the absolute angle signal output from the rotation angle detection apparatus of the embodiment. The flowchart which shows the process sequence about the process which determines which signal of a relative angle signal and an absolute angle signal is output by the rotation angle detection apparatus of the embodiment. The graph which shows the relationship between the steering angle of a steering wheel, its relative angle, and an absolute angle.

  Hereinafter, an embodiment in which a rotation angle detection device according to the present invention is embodied as a device for detecting the steering angle of a steering wheel of a vehicle will be described with reference to FIGS. Here, FIG. 1 shows a planar structure of the rotation angle detection device according to the present embodiment, and FIG. 2 shows a cross-sectional structure taken along the line II-II of FIG. With reference to FIG. 1 and FIG. 2, a schematic configuration of the rotation angle detection device according to the present embodiment will be described. In FIG. 1, for the sake of convenience, the illustration of a housing (housing 15 in FIG. 2) that protects various components constituting the rotation angle detection device from the external environment is omitted.

  As shown in FIG. 1, this rotation angle detection device is also basically the same in configuration for detecting the steering angle of the steering wheel as the rotation angle detection device described in Patent Document 2 above. That is, the rotation angle detection device has a main gear 10 that is integrally fitted to the outer periphery of a steering shaft S that functions as a rotation shaft of a steering wheel (not shown) of a vehicle. Accordingly, the main gear 10 is configured to rotate in the direction indicated by the arrows c1 and c2 in the drawing around the central axis C in the drawing. Further, the first detection gear 11 is meshed with the outer teeth of the main gear 10, and the second detection gear 12 having a different number of teeth from the first detection gear 11 is also meshed. Incidentally, as shown in FIG. 2, a convex portion 11 a that engages a concave portion 15 a formed on the inner wall surface of the housing 15 is provided at the center of the first detection gear 11. The first detection gear 11 is supported so as to be rotatable about the convex portion 11 a by the combined structure and the holding member 19 that holds the bottom of the first detection gear 11. In addition, a first magnet 13 is fixedly disposed on the surface of the first detection gear 11 opposite to the surface on which the convex portion 11 a is formed, and the first detection gear 11 is rotated. Accordingly, the first magnet 13 rotates around the convex portion 11a. That is, the direction of the magnetic field emitted from the first magnet 13 changes as the first detection gear 11 rotates. Further, a substrate 18 is disposed in a portion of the housing 15 that faces the first magnet 13, and the first detection gear according to the direction of the magnetic field emitted from the magnet 13 is arranged on the substrate 18. A first magnetic detection unit 16 that outputs a voltage signal corresponding to the rotation angle of 11 is mounted.

  Incidentally, the structure of the second detection gear 12 is similar to the structure of the first detection gear 11, and the second detection gear 12 also rotates around a convex portion 12a formed at the center thereof. The second magnet 14 is fixedly disposed on the second detection gear 12 while being supported. Further, the housing 15 receives a voltage signal corresponding to the direction of the magnetic field emitted from the magnet 14 so as to face the second magnet 14, in other words, the voltage signal corresponding to the rotation angle of the second detection gear 12. A second magnetic detector 17 for outputting is disposed.

  The first and second magnetic detectors 16 and 17 have a resistance value due to the magnetoresistive effect in accordance with the direction of the applied magnetic field, as in the rotation angle detectors described in Patent Documents 1 and 2 above. It consists of a changing magnetoresistive element.

  In this rotation angle detection device, when the steering shaft S is rotated in accordance with the rotation operation of the steering wheel by the user, the main gear 10 is rotated, and accordingly, the first and second detection gears 11 and 12 are rotated. Move. Further, when the first and second magnets 13 and 14 are rotated as the first and second detection gears 11 and 12 are rotated, the directions of the magnetic fields generated from the magnets 13 and 14 are changed. The voltage signals of the first and second magnetic detectors 16 and 17 change, respectively. In this rotation angle detection device, the rotation angle of the main gear 10 based on the voltage signals of the first and second magnetic detectors 16 and 17, in other words, the steering angle of the steering wheel is determined as an absolute angle and a relative angle. Detect by angle.

  FIG. 3 is a block diagram showing the system configuration of the rotation angle detection device. Next, with reference to FIG. 3, the configuration of the rotation angle detection device according to the present embodiment will be described more specifically. To do.

  As shown in FIG. 3, the output signals of the first and second magnetic detectors 16 and 17 function as a part for detecting the steering angle of the steering wheel based on these signals as an absolute angle and a relative angle. Is input to a microcomputer 20. In other words, the microcomputer 20 executes the calculation process according to the calculation process by the rotation angle detection device described in Patent Document 1 based on the output signal of the first magnetic detection unit 16, thereby rotating the main gear 10. A signal indicating a relative angle is generated. In other words, a signal indicating the relative angle of the steering wheel steering angle (relative angle signal) is generated. In addition, the microcomputer 20 executes arithmetic processing according to the arithmetic processing by the rotation angle detection device described in Patent Document 2 based on the output signals of the first and second magnetic detection units 16 and 17. Thus, a signal indicating the absolute angle of the rotation angle of the main gear 10 is generated. In other words, a signal (absolute angle signal) indicating the absolute angle of the steering angle of the steering wheel is generated.

  In addition, the vehicle includes a skid prevention system control device 30 that comprehensively executes various controls related to the above-described skid prevention system, and a BGM system control device 31 that collectively executes various controls related to the above-described BGM system. Is installed. However, some vehicles are equipped only with a skid prevention system, and such a vehicle has only the skid prevention system control device 30. Some vehicles have only the BGM system installed, and such vehicles have only the BGM system control device 31. The skid prevention system control device 30 executes various controls related to the skid prevention system based on the relative angle of the steering wheel, and the BGM system control device 31 applies the BGM system based on the absolute angle of the steering wheel. Perform various controls.

  The non-volatile memory 30a built in the skid prevention system control device 30 includes necessary angle information indicating that the relative angle of the steering wheel is necessary, and the non-volatile memory built in the BGM system control device 31. The required memory information indicating that the absolute angle of the steering wheel is required is stored in the memory 31a. Here, the microcomputer 20 acquires the necessary angle information stored in the memories 30a and 31a of the respective control devices 30 and 31, and based on the acquired necessary angle information, either the relative angle signal or the absolute angle signal. It is determined whether or not the signal is output to the control devices 30 and 31. Further, the microcomputer 20 generates either a relative angle signal or an absolute angle signal based on the determination result, and outputs the generated signal to the control devices 30 and 31.

  Incidentally, as shown in the figure, the rotation angle detection device according to the present embodiment is provided with a constant voltage circuit 21 that outputs a constant voltage based on the voltage of the in-vehicle battery 40. A driving power supply for the first and second magnetic detectors 16 and 17 and the microcomputer 20 is secured by the output constant voltage. Moreover, in the same figure, the code | symbol 41 has shown the ignition switch of the said vehicle.

  Next, the relative angle signal α and the absolute angle signal β generated through the microcomputer 20 will be described with reference to FIGS. 4 and 5 show examples of signal waveforms of the relative angle signal α and the absolute angle signal β, respectively, with the steering angle θ of the steering wheel as the horizontal axis and the relative angle signal α and the absolute angle signal β as the vertical axis. It is a thing. 4 and 5, the steering angle θ when the steering wheel is located at a predetermined reference position is indicated as “0 °”. The steering angle θ of the steering wheel is shown as changing to a positive value when the main gear 10 rotates in the direction indicated by the arrow c1.

  As shown in FIG. 4, the relative angle signal α indicates that, for example, the steering angle θ of the steering wheel has an output resolution of “1 °” and a range of “0 ° to 89 °” or “90 ° to 179 °”. It is a signal that changes linearly in the range of “0 to 89” when it changes in the range. In other words, the relative angle signal α is a signal that changes monotonically and changes in a sawtooth shape every time the steering angle θ of the steering wheel changes by “90 °”.

  On the other hand, as shown in FIG. 5, the absolute angle signal β changes linearly in the range of “0 to 1620” when the steering angle θ of the steering wheel changes in the range of “0 ° to 1620 °”, for example. And a value corresponding to the steering angle θ on a one-to-one basis. Incidentally, if the steering angle θ of the steering wheel takes a value outside the range of “0 ° to 1620 °”, this absolute angle signal β does not correspond to the value of the steering angle θ on a one-to-one basis. Overflow occurs.

  FIG. 6 shows the processing procedure for determining which of the relative angle signal α and the absolute angle signal β is generated and outputted to each of the control devices 30 and 31, which is executed through the microcomputer 20. Is shown as a flowchart, and the specific procedure of the process will be summarized below based on FIG. The process shown in FIG. 6 is executed when the ignition switch 41 is turned on for the first time after the vehicle is assembled and a constant voltage is first supplied to the microcomputer 20 via the constant voltage circuit 21.

  As shown in FIG. 6, in this process, first, necessary angle information of each control system is acquired (step S1). Specifically, for example, in a vehicle equipped with both a skid prevention system and a BGM system, necessary angle information is acquired from the memories 30a and 31a of the control devices 30 and 31. On the other hand, for example, in a vehicle equipped with only a skid prevention system, necessary angle information is acquired only from the skid prevention system control device 30.

  Then, following the process of step S1, it is determined whether or not there is a control system that requires the absolute angle of the steering wheel based on the acquired necessary angle information (step S2). Specifically, first, based on the acquired necessary angle information, it is determined whether each of the control devices 30 and 31 requires a relative angle or an absolute angle of the steering wheel. Subsequently, when it is detected that there is at least one control device that requires the absolute angle of the steering wheel based on the determination result, there is a control system that requires the absolute angle of the steering wheel. Is determined.

  When it is determined that there is a control system that requires an absolute angle signal (step S2: YES), the absolute angle signal β is generated and the generated absolute angle signal β is The microcomputer 20 is set in a state of outputting to the control devices 30 and 31 (step S3), and the microcomputer 20 ends this series of processes.

  On the other hand, if it is detected in the process in step S2 that there is no control system that requires the absolute angle of the steering wheel based on the acquired necessary angle information, in other words, the relative angle of the steering wheel is determined. When it is detected that only the necessary control system exists, it is determined that there is no system that requires the absolute angle (step S2: NO). In this case, the relative angle signal α is generated, and the generated relative angle signal α is set to be output to the control devices 30 and 31 (step S4). Exit.

  According to such a configuration as the rotation angle detection device, the absolute angle signal β is output to each of the control devices 30 and 31 in a vehicle in which both the skid prevention system and the BGM system are mounted. Similarly, the absolute angle signal β is output to the BGM system control device 31 even in a vehicle on which only the BGM system is mounted. For this reason, normal operation of the BGM system control device 31 can be ensured. On the other hand, in a vehicle equipped with only the skid prevention system, the relative angle signal α is output to the skid prevention system control device 30. As a result of the relative angle signal α being output to the skid prevention system control device 30 in this way, even if an abnormal situation occurs in which the rotation angle detection device is erroneously assembled to the steering shaft S. The signal input to the skid prevention system control device 30 does not overflow. Therefore, even if such an abnormal situation occurs, the proper operation of the skid prevention system control device 30 can be ensured, so that the malfunction of the skid prevention system can be suppressed.

  The rotation angle detection device according to the present embodiment employs a configuration in which, for example, the relative angle signal α is output to the skid prevention system control device 30 and the absolute angle signal β is output to the BGM system control device 31. It is also possible for the time being. However, even if such a configuration is adopted, if the absolute angle signal β overflows, the BGM system control device 31 will eventually malfunction. If the BGM system control device 31 malfunctions in this way, the function of the BGM system of the vehicle will not operate normally, and there is a risk of hindering normal operation of the entire vehicle. Therefore, as in the rotation angle detection device according to the present embodiment, a configuration in which the relative angle signal α is output to the skid prevention system control device 30 only when only the skid prevention system is mounted on the vehicle is adopted. By doing so, it is possible to sufficiently obtain the effect of ensuring the normal operation of the entire vehicle.

As described above, according to the rotation angle detection device according to the present embodiment, the following effects can be obtained.
(1) Each control device 30, 31 determines which of the steering wheel relative angle or absolute angle is required, and at least one control system that requires the absolute angle of the steering wheel based on the determination result. When detected, an absolute angle signal β is output to each of the control devices 30 and 31. When only a system that requires the relative angle of the steering wheel is detected, the relative angle signal α is output to each of the control devices 30 and 31. Accordingly, normal operation of the BGM system control device 31 can be ensured in a vehicle in which both the skid prevention system and the BGM system are mounted, or in a vehicle in which only the BGM system is mounted. Further, in a vehicle equipped with only a skid prevention system, even if an abnormal situation occurs in which the rotation angle detection device is erroneously assembled to the steering shaft S, proper operation of the skid prevention system control device 30 is ensured. Therefore, the malfunction of the skid prevention system can be suppressed. Further, if such a configuration is adopted, it is possible to sufficiently obtain an effect of ensuring normal operation of the entire vehicle.

  (2) Necessary angle information indicating which of the steering wheel relative angle and absolute angle is necessary is stored in advance in the memories 30a and 31a of the control devices 30 and 31, respectively. And the required angle information memorize | stored in memory 30a, 31a is acquired, and it is judged whether each control apparatus 30 and 31 requires a relative angle or an absolute angle based on the acquired required angle information. did. Thereby, it becomes possible to easily determine which of the relative angle and the absolute angle each control device 30, 31 requires.

  (3) The relative angle and absolute angle of the steering wheel are detected using the rotation angle detection device described in the above-mentioned Patent Document 2. Thereby, the relative angle and absolute angle of the steering wheel can be easily detected.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In a vehicle equipped with both a skid prevention system and a BGM system, the relative angle signal α is output to the skid prevention system control device 30 and the absolute angle signal β is output to the BGM system control device 31. Also good. By adopting such a configuration, even if an abnormal situation occurs in which the rotation angle detection device is erroneously assembled to the steering shaft S and an overflow occurs in the absolute angle signal β, at least the skid prevention system control device 30 Since proper operation can be ensured, it is possible to avoid malfunction of the skid prevention system.

  In the above embodiment, when the ignition switch 41 is turned on for the first time after the vehicle is assembled and a constant voltage is supplied to the microcomputer 20 for the first time through the constant voltage circuit 21, the processing illustrated in FIG. I did it. Instead of this, for example, the process illustrated in FIG. 6 may be executed every time the ignition switch 41 is turned on.

  -In the above embodiment, the necessary angle information indicating which of the steering wheel relative angle and absolute angle is necessary is stored in advance in the memories 30a, 31a of the control devices 30, 31, and this is necessary. By acquiring angle information, it is determined whether each control device requires a relative angle or an absolute angle. Instead of this, for example, information indicating which of the relative angles or absolute angles of the steering wheels is required for each of the control devices 30 and 31 is stored in a memory built in the microcomputer 20. And based on the information memorize | stored in the memory of this microcomputer 20, you may make it judge whether each control apparatus 30 and 31 requires a relative angle or an absolute angle. In short, any rotational angle detection device that can determine which of the relative angle and absolute angle of the steering wheel each control device 30, 31 is required in the microcomputer 20 may be used.

  In the above embodiment, the absolute angle and the relative angle of the steering wheel are detected by using the rotation angle detection device described in Patent Document 2, that is, the rotation angle detection device including one main gear 10 and two detection gears. I tried to do it. Instead of this, for example, a plurality of slit rows having different patterns are provided in the circumferential direction of the main gear 10, and a photosensor is disposed at a position corresponding to each slit row. And you may make it detect the relative angle and absolute angle of a steering wheel based on the signal output from each optical sensor according to the presence or absence of the slit of these slit rows. In short, any rotation angle detection device capable of detecting the steering angle of the steering wheel as a relative angle and an absolute angle may be used.

  -Even if the skid prevention system control device 30 requires an absolute angle of the steering wheel and the BGM system control device 31 requires the relative angle, the present invention can be similarly applied. it can. Moreover, even if each control device 30, 31 requires the absolute angle of the steering wheel, or even if they require the relative angle of the steering wheel, the present invention is similarly applied. Can do.

  In the above-described embodiment, the skid prevention system control device 30 and the BGM system control device 31 are employed as the targets for outputting the relative angle signal or the absolute angle signal. Instead of or in addition to these control devices, for example, after eliminating mechanical connection between the steering wheel and the steering wheel of the vehicle, the steering wheel is changed based on the steering angle of the steering wheel. You may make it employ | adopt the control apparatus which manages the various control collectively about what is called steer-by-wire system made to steer. That is, the target for outputting the relative angle signal or the absolute angle signal may be a control device that executes various controls based on the relative angle or the absolute angle of the steering wheel.

  In the above embodiment, the steering wheel of the vehicle is adopted as the rotating body to be detected. However, the rotation that outputs the angle information to various control systems that require the relative angle or absolute angle of the rotating body such as the shaft. If it is an angle detection apparatus, the rotation angle detection apparatus concerning this invention can be applied suitably.

Using the rotation angle detection device according to the above embodiment, for example, it is detected that the absolute angle signal β may overflow in a situation where the absolute angle signal β is output to each of the control devices 30, 31. Sometimes, it is possible to perform control such that the signal output to each of the control devices 30 and 31 is switched from the absolute angle signal β to the relative angle signal α.
(Appendix)
Next, a technical idea that can be grasped from the above embodiment and its modifications will be additionally described.

  (A) In the rotation angle detection device according to any one of claims 1 to 3, a main gear that rotates integrally with the rotating body, a first detection gear that meshes with the main gear, and the first gear A second detection gear that has a different number of teeth from that of the first detection gear and meshes with the main gear, a first signal output unit that outputs a signal according to a rotation angle of the first detection gear, A second signal output unit that outputs a signal corresponding to the rotation angle of the second detection gear, and based on the output signal of one of the first and second signal output units, A rotation angle detection device that generates a signal indicating a relative angle and generates a signal indicating the absolute angle based on output signals of both the first and second signal output units. According to this configuration, basically, the absolute angle and relative angle of the rotating body can be detected using the rotation angle detecting device described in the above-mentioned Patent Document 2. A rotation angle detection device that can detect both relative angles can be easily realized. That is, the rotation angle detection device according to the first to third aspects can be easily realized.

  (B) The rotation angle detection device according to any one of claims 1 to 3 and appendix i, wherein the rotating body is a steering wheel of a vehicle. As described above, a vehicle may be equipped with a plurality of control systems that perform various controls using the relative angle of the steering angle of the steering wheel or the absolute angle thereof. Therefore, it is significant that the devices according to claims 1 to 3 and the supplementary note (i) are applied to a rotation angle detection device that detects the steering angle of the steering wheel.

  DESCRIPTION OF SYMBOLS 10 ... Main gear, 11 ... 1st detection gear, 11a ... Convex part, 12 ... 2nd detection gear, 12a ... Convex part, 13 ... 1st magnet, 14 ... 2nd magnet, 15 ... Housing, 15a ... Concave part, 16 ... 1st magnetic detection part, 17 ... 2nd magnetic detection part, 18 ... Board | substrate, 19 ... Holding member, 20 ... Microcomputer (microcomputer), 21 ... Constant voltage circuit, 30 ... Side slip prevention system control apparatus , 30a, 31a ... memory, 31 ... BGM system control device, 40 ... in-vehicle battery, 41 ... ignition switch.

Claims (3)

It is possible to detect the rotation angle of the rotating body to be detected as a relative angle and an absolute angle, and various signals indicating the detected relative angle and signals indicating the absolute angle are used based on the rotation angle of the rotating body. In the rotation angle detection device that outputs to a control system that executes control,
It is determined whether the control system requires the relative angle or the absolute angle, and based on the determination result, either a signal indicating the relative angle or a signal indicating the absolute angle is output to the control system. A rotation angle detection device characterized by determining whether to perform. The control system stores in advance necessary angle information indicating whether the relative angle or the absolute angle is necessary, and determines whether the control system requires the relative angle or the absolute angle. 2. The rotation according to claim 1, wherein the required angle information is acquired from the control system, and the control system determines which of the relative angle and the absolute angle is required based on the acquired required angle information. Angle detection device. When it is detected that at least one system requiring the absolute angle exists in the control system, a signal indicating the absolute angle is output to all of the control systems, and all of the control systems 3. The rotation angle detection device according to claim 1, wherein when it is detected that the system requires a relative angle, a signal indicating the relative angle is output to all of the control systems. 4.

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