JP4443585B2 - Sensor system for variable transmission ratio mechanism and steering device using the same - Google Patents

Description

  The present invention is a vehicle steering apparatus configured to mechanically add a sub-rotation angle that can be electrically controlled by a transmission ratio variable mechanism to a steering angle of a driver and to steer a wheel. The present invention relates to a sensor system for a variable transmission ratio mechanism that detects a steering angle of a driver and a steering angle of a wheel, and a steering device using the same.

Conventionally, as a steering device that is equipped with a variable transmission ratio mechanism between the steering wheel and the steering wheel, and changes the transmission characteristic of the steering wheel turning angle with respect to the steering angle of the driver according to the driving state of the vehicle. For example, there is a steering device as described in Patent Document 1.
Since this apparatus uses a relative angle sensor to detect the steering angle of the steering wheel, the steering angle of the steering wheel at the time of activation cannot be detected as an absolute angle. Therefore, when the device is started, the control is started by estimating the steering wheel angle and the turning angle using the sub rotation angle stored as the absolute angle, and based on the difference between the left and right wheel speeds while the vehicle is running. In this document, a steering angle is detected to correct the steering angle and the steering angle.
Moreover, there exists an apparatus described in patent document 2 as an apparatus which detects the absolute angle also including multiple rotations of a shaft.
In this apparatus, a configuration is shown that includes a gear that rotates together with a shaft and two gears that rotate while meshing with the gear. An absolute angle including multiple rotations of the shaft is detected by detecting an absolute angle of one rotation of the rotation angles of the two gears using an angle detection element and performing a predetermined calculation.

Japanese Patent No. 3518590 (pages 3-9, FIG. 1) Japanese Patent Publication No. 11-500828 (pages 6-17, FIG. 1)

In such a steering device, the transmission characteristic of the steering wheel to the steering angle with respect to the steering angle of the steering wheel is determined from the vehicle running state such as the vehicle speed and the steering wheel steering speed, and the target rotation is determined from the steering wheel angle θh and the transmission characteristic. The steering angle θpref is determined. Alternatively, the target sub-rotation absolute angle θsref is determined using characteristics determined by the target turning angle and the mechanical configuration of the transmission ratio variable mechanism. As a sensor for detecting the steering wheel angle θh or the turning angle θp of the vehicle, a rotary encoder or the like is used as disclosed in Patent Document 1.
This rotary encoder outputs a two-phase pulse signal as an output. By counting this signal, an angle can be obtained, and an absolute angle cannot be detected at startup. Therefore, in Patent Document 1, the steering wheel angle θh and the turning angle θp are estimated using the sub-rotation absolute angle θs that is recorded as an absolute angle and does not rotate while the apparatus is stopped, and the transmission characteristics. Here, if the steering wheel is steered while the device is stopped, the above assumption is lost and the estimation is incorrect. Therefore, the neutral position of the steering wheel and the neutral position of the steering wheel are set differently from the true neutral position, respectively. It will be.
In order to solve this problem, this Patent Document 1 is configured to detect and correct the turning angle based on the difference between the left and right wheel speeds while the vehicle is traveling. For this reason, immediately after the start of the apparatus, there is a problem that even if the neutral position of the steering wheel and the neutral position of the steering wheel are different from the true neutral position, the detection cannot be performed.
Further, in order to detect the steering wheel steering angle and the turning angle as an absolute angle immediately after startup, the angle sensors described in Patent Document 2 may be installed in each, but the angle sensor detects two angles. Since the elements are necessary, there is a problem that a total of four angle detection elements are necessary.

  The present invention has been made in order to solve the above-described problems. From the time of start-up, the steering absolute angle of the steering wheel, the auxiliary rotation absolute angle of the transmission ratio variable mechanism, and the steering steering absolute angle of the steered wheels can be easily simplified. An object of the present invention is to obtain a sensor system for a transmission ratio variable mechanism that is detected with a simple configuration and a steering device using the same.

In the sensor system for a variable transmission ratio mechanism according to the present invention, the first steering shaft that rotates integrally with the steering handle, and the second steering shaft that rotates integrally with the member that steers the steered wheels. A sensor system for a transmission ratio variable mechanism used in a transmission ratio variable mechanism that changes a transmission characteristic of a rotational operation by superimposing a sub-rotation angle,
A first absolute angle sensor that repeatedly detects an absolute angle within a first predetermined angle range for each first predetermined angle of the first steering shaft, and the second steering shaft in a state where the sub rotation angle is fixed A second absolute angle sensor that repeatedly detects an absolute angle within a second predetermined angle range and a sub-rotation absolute angle detection that detects an absolute angle including multiple rotation components of the sub-rotation angle for each second predetermined angle With means,
Based on the output of the first absolute angle sensor, the output of the second absolute angle sensor, the output of the auxiliary rotation absolute angle detection means, and the characteristics of the transmission ratio variable mechanism, the absolute value including the multi-rotation component of the first steering shaft. One or both of a first steering shaft absolute angle calculating means for calculating an angle and a second steering absolute angle calculating means for calculating an absolute angle including a multi-rotation component of the second steering shaft are provided. .

As described above, according to the present invention, transmission of rotational motion between the first steering shaft that rotates integrally with the steering handle and the second steering shaft that rotates integrally with the member that steers the steered wheels is transmitted. A transmission ratio variable mechanism sensor system used for a transmission ratio variable mechanism that changes characteristics by superimposing a sub-rotation angle,
A first absolute angle sensor that repeatedly detects an absolute angle within a first predetermined angle range for each first predetermined angle of the first steering shaft, and the second steering shaft in a state where the sub rotation angle is fixed A second absolute angle sensor that repeatedly detects an absolute angle within a second predetermined angle range and a sub-rotation absolute angle detection that detects an absolute angle including multiple rotation components of the sub-rotation angle for each second predetermined angle With means,
Based on the output of the first absolute angle sensor, the output of the second absolute angle sensor, the output of the sub-rotation absolute angle detection means, and the characteristics of the transmission ratio variable mechanism, the absolute value including the multi-rotation component of the first steering shaft. Since either or both of the first steering shaft absolute angle calculating means for calculating the angle and the second steering absolute angle calculating means for calculating the absolute angle including the multi-rotation component of the second steering shaft are provided, Even if the steering wheel is steered at the time of control, the absolute angle including the multiple rotations of the first steering shaft and the second steering shaft from the time when the sensor system for the variable transmission ratio mechanism is started is It can be detected by the second absolute angle sensor and the sub-rotation absolute angle detection means.

Embodiment 1 FIG.
1 is a block diagram showing a transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
In FIG. 1, the transmission ratio variable mechanism 1 is driven by a driving means 8 that rotates at a rotation angle of a first steering shaft 2 that rotates together with a steering wheel 3 that is steered by a driver according to a command from a control device (not shown). The second steering shaft 4 that rotates integrally with the member of the steering mechanism 5 that steers the steered wheels is rotated by superimposing the generated sub rotation angle.
The first absolute angle sensor 6 is attached to the first steering shaft 2 and repeatedly detects an absolute angle within a first predetermined angle range, and rotates integrally with the first steering shaft 2. The first gear 601 is engaged with the first gear 601 and the second gear 602 having a predetermined speed increasing ratio and the absolute angle of the rotation angle of the second gear 602 in the range of 0 ° to 360 °. It comprises the 1st angle sensor 603 detected by.
The second absolute angle sensor 7 is attached to the second steering shaft 4 and repeatedly detects an absolute angle within a second predetermined angle range, and rotates integrally with the second steering shaft 4. The third gear 701 is engaged with the third gear 701, the fourth gear 702 having a predetermined speed increase ratio, and the absolute angle of the rotation angle of the fourth gear 702 in the range of 0 ° to 360 °. The second angle sensor 703 detected by

The sub-rotation absolute angle detection means 9 is installed anywhere from the drive means 8 to the member that superimposes the sub-rotation angle in the transmission ratio variable mechanism 1 and is substantially superimposed by the transmission ratio variable mechanism 1. The absolute angle of the sub rotation angle is detected.
The first absolute angle calculation means 10 (first steering shaft absolute angle calculation means) receives the outputs of the first absolute angle sensor 6, the second absolute angle sensor 7, and the auxiliary rotation absolute angle detection means 9, By calculating according to a predetermined procedure, the rotation angle of the first steering shaft 2 is calculated as an absolute angle.
The second absolute angle calculation means 11 (second steering shaft absolute angle calculation means) receives the outputs of the first absolute angle sensor 6, the second absolute angle sensor 7, and the auxiliary rotation absolute angle detection means 9, By calculating according to a predetermined procedure, the rotation angle of the second steering shaft 4 is calculated as an absolute angle.
The steering device sets the target sub-rotation angle based on the output of the first absolute angle calculation means 10, and sets the transmission ratio variable mechanism so that the output of the sub-rotation absolute angle detection means 9 matches the target sub-rotation angle. The target second absolute angle is set based on the first control means to be controlled and the output of the first absolute angle calculation means 10, and the output of the second absolute angle calculation means 11 and the target second absolute angle are set. Is provided with one of the second control means for controlling the transmission ratio variable mechanism (transmission ratio variable mechanism control means) so as to match.

FIG. 2 is a diagram for explaining the processing outline of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
In FIG. 2, the horizontal axis is the first (second) steering shaft rotation angle (°). 2 (a) to 2 (c), FIG. 2 (f), and FIG. 2 (g) are output values (°), and FIG. 2 (d) and FIG. It is.
2A shows the first absolute angle sensor output, FIG. 2B shows the second absolute angle sensor output, and FIG. 2C shows the first absolute angle sensor output and the second absolute angle. The phase difference of the sensor output, FIG. 2 (d) is the first calculated number of iterations, FIG. 2 (e) is the second calculated number of iterations, FIG. 2 (f) is the first calculated steering shaft rotation angle, FIG. 2G shows a second steering shaft rotation angle calculation value.

FIG. 3 is a diagram illustrating a method for calculating the number of repetitions from the deviation of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
In FIG. 3, the first absolute angle sensor 6 and the second absolute angle sensor 7 when the first steering shaft 2 is rotated in a state where the sub rotation angle of the transmission ratio variable mechanism 1 is fixed at 0 °. The output is shown.

FIG. 4 is a diagram showing an output example of the first absolute angle sensor, the second absolute angle sensor, and the auxiliary rotation absolute angle detection means of the sensor system for the transmission ratio variable mechanism according to Embodiment 1 of the present invention.
4A shows the first steering shaft rotation angle (°), FIG. 4B shows the sub-rotation angle (°), FIG. 4C shows the second steering shaft rotation angle (°), and FIG. d) is the first absolute angle sensor output (°), FIG. 4 (e) is the sub rotation angle sensor output (°), and FIG. 4 (f) is the second absolute angle sensor output (°).
FIG. 5 is a flowchart showing the operation of the first absolute angle calculating means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.

FIG. 6 is a characteristic diagram for explaining the operation of the first absolute angle calculation means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
6A is the first absolute angle sensor output (°), FIG. 6B is the sub-rotation absolute angle detection means output (°), and FIG. 6C is the second absolute angle sensor output (°). 6D is a second absolute angle sensor correction output (°), FIG. 6E is a phase difference (°) between the first absolute angle sensor output and the second absolute angle sensor correction output, FIG. 6 (f) is the output (°) of the number of repetitions of the first absolute angle sensor, and FIG. 6 (g) is the first steering shaft rotation angle detection output (°).

FIG. 7 is a flowchart showing the operation of the second absolute angle calculating means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
FIG. 8 is a characteristic diagram for explaining the operation of the second absolute angle calculating means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
8A shows the first absolute angle sensor output (°), FIG. 8B shows the sub-rotation absolute angle detection means output (°), and FIG. 8C shows the second absolute angle sensor output (°). 8D shows the first absolute angle sensor correction output (°), FIG. 8E shows the phase difference (°) between the first absolute angle sensor correction output and the second absolute angle sensor output, and FIG. 8 (f) is a second absolute angle sensor repeat count output (°), and FIG. 8G is a second steering shaft rotation angle detection output (°).

FIG. 9 is a diagram illustrating a problem when there is an error between the first absolute angle sensor output and the second absolute angle sensor output of the sensor system for the variable transmission ratio mechanism according to the first embodiment of the present invention.
In FIG. 9, the horizontal axis is the first (second) steering shaft rotation angle (°). 9 (a) to 9 (c), 9 (f), and 9 (g) are output values (°), and FIGS. 9 (d) and 9 (e) are the number of times. It is.
9A shows the first absolute angle sensor output, FIG. 9B shows the second absolute angle sensor output, and FIG. 9C shows the first absolute angle sensor output and the second absolute angle. The phase difference of the sensor output, FIG. 9 (d) is the first calculated number of iterations, FIG. 9 (e) is the second number of repeated calculations, FIG. 9 (f) is the first steering shaft rotation angle calculated value, FIG. 9G shows the second steering shaft rotation angle calculation value.

FIG. 10 is a diagram for explaining the cause of the problem when there is an error between the first absolute angle sensor output and the second absolute angle sensor output in the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention. .
In FIG. 10, the horizontal axis represents the first (second) steering shaft rotation angle (°). The vertical axis represents the output values (°) in FIGS. 10 (a) and 10 (d). The other is the output of the processing step.
10A shows the output of the first absolute angle sensor, FIG. 10B shows the output of step 1006a, FIG. 10C shows the output of step 1006b, and FIG. 10D shows the second absolute angle. FIG. 10E shows the sensor output, FIG. 10E shows the output of step 1106a, and FIG. 10F shows the output of step 1106b.

FIG. 11 is a diagram for explaining another problem when there is an error between the first absolute angle sensor output and the second absolute angle sensor output of the sensor system for the variable transmission ratio mechanism according to the first embodiment of the present invention. is there.
In FIG. 11, the horizontal axis represents the first (second) steering shaft rotation angle (°). 11 (a) to 11 (c), FIG. 11 (f), and FIG. 11 (g) are output values (°), and FIG. 11 (d) and FIG. It is.
11A shows the first absolute angle sensor output, FIG. 11B shows the second absolute angle sensor output, and FIG. 11C shows the first absolute angle sensor output and the second absolute angle. The phase difference of the sensor output, FIG. 11 (d) is the first calculated number of repetitions, FIG. 11 (e) is the second calculated number of repetitions, FIG. 11 (f) is the first calculated steering shaft rotation angle, FIG. 11G shows a second steering shaft rotation angle calculation value.

FIG. 12 is a diagram for explaining another cause of a problem when there is an error between the absolute angle sensor output 1 and the second absolute angle sensor output in the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention. is there.
In FIG. 12, the horizontal axis represents the first (second) steering shaft rotation angle (°). The vertical axis represents the output value (°) in FIGS. 12 (a) and 12 (d). The other is the output of the processing step.
12A shows the output of the first absolute angle sensor, FIG. 12B shows the output of step 1006a, FIG. 12C shows the output of step 1006b, and FIG. 12D shows the second absolute angle. The sensor output, FIG. 12E shows the output of step 1106a, and FIG. 12F shows the output of step 1106b.

FIG. 13 is a block diagram showing the sub rotation absolute angle detecting means of the sensor system for variable transmission ratio mechanism according to the first embodiment of the present invention.
In FIG. 13, 1, 8, and 9 are the same as those in FIG. FIG. 13 illustrates the details of the sub-rotation absolute angle detection means 9. In the transmission ratio variable mechanism 1, the sub rotation angle is superimposed by the driving means 8. The drive means 8 is mainly composed of an electric motor.
The auxiliary rotation angle sensor 901 detects the rotation angle of the driving means 8 as an absolute angle, and for example, a resolver or the like is used. The sub-rotation absolute angle calculation means 902 receives the output of the sub-rotation angle sensor 901 and outputs the sub-rotation absolute angle φ1 superimposed by the transmission ratio variable mechanism 1. A storage unit 903 is a sub-rotation absolute angle calculation unit 902 that holds a value necessary for calculating the sub-rotation absolute angle at the end of the control, and calculates the sub-rotation absolute angle when control is resumed by the transmission ratio variable mechanism control unit. An initial value in means 902 is provided. The auxiliary rotation angle limiting means 12 limits the rotation of the driving means 8 during non-control. The sub-rotation angle limiting unit 12 is described so as to limit the rotation angle of the driving unit 8, but may be arranged anywhere as long as the sub-rotation angle is limited.

FIG. 14 is a flowchart showing the operation of the sub rotation absolute angle detecting means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
FIG. 15 is a diagram for explaining the operation of the sub-rotation absolute angle detecting means of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.
15A shows the rotation angle (°) of the drive means, FIG. 15B shows the sub rotation angle sensor φs (°), FIG. 15C shows the sub rotation angle repetition count φc, and FIG. 15D. Is the calculated rotation angle φM of the driving means, and FIG. 15E is the calculated sub rotation absolute angle φ1 (°).
FIG. 16 is a diagram for explaining the operation of the encoder of the sensor system for the variable transmission ratio mechanism according to the first embodiment of the present invention.

  FIG. 17 is a flowchart showing the operation of the sub-rotation absolute angle detection means using the encoder of the transmission ratio variable mechanism sensor system according to Embodiment 1 of the present invention.

が成り立つように構成されている。 Next, the operation will be described.
First, the transmission ratio variable mechanism 1 will be briefly described.
Conventionally, the first steering shaft 2 that rotates integrally with the handle 1 is superposed with a sub-rotation angle by the driving means 8 such as an electric motor, and rotates together with a member that steers the steered wheels. Many types of mechanisms for rotating the second steering shaft, such as a type using a planetary gear, are disclosed. In this mechanism, if the rotation angle of the first steering shaft 2 is θ, the sub rotation angle is φ, and the rotation angle of the second steering shaft 4 is δ,

Is configured to hold.

※ｍｏｄ（ａ，ｂ）は、ａをｂで割ったときの剰余（正の値）を示す。
となる。この第２の歯車の回転角θ１は、第１の角度センサ６０３により検出される。第１の角度センサ６０３は、第２の歯車６０２の回転角を絶対角（１回転範囲：０°〜３６０°）で検出するものが適用されている。例えば、第２の歯車６０２にＮＳ磁石を配置し、第２の歯車６０２の回転角と一致するＮＳ磁石より生じる磁力線の方向を検出するセンサや、光学的・磁気的に回転角コードを記録した部材を第２の歯車６０２と一体に回転させ、ピックアップにより回転角コードを検出するものがある。いずれのセンサを適用したとしても、第２の歯車６０２は、第１のステアリングシャフト２が、所定の角度（Δθ）

回転する毎に１回転する。
従って、第１の絶対角センサ６は、第１のステアリングシャフト２の第１の所定角度範囲Δθ毎に、第１の所定角度範囲内の絶対角θ１を繰り返し検出することができる。 The first gear 601 of the first absolute angle sensor 6 rotates integrally with the first steering shaft 2, and the rotation is transmitted to the second gear 602 by gear meshing. Here, assuming that the speed increasing ratio between the first gear 601 and the second gear 602 is G1, the rotation angle θ1 of the second gear has an angular range of 0 ° to 360 °.

* Mod (a, b) indicates a remainder (positive value) when a is divided by b.
It becomes. The rotation angle θ1 of the second gear is detected by the first angle sensor 603. As the first angle sensor 603, one that detects the rotation angle of the second gear 602 as an absolute angle (one rotation range: 0 ° to 360 °) is applied. For example, an NS magnet is arranged on the second gear 602, and a sensor for detecting the direction of the lines of magnetic force generated from the NS magnet coinciding with the rotation angle of the second gear 602, or a rotation angle code optically and magnetically recorded. Some members rotate a member integrally with the second gear 602 and detect a rotation angle code by a pickup. Regardless of which sensor is applied, the second gear 602 is such that the first steering shaft 2 has a predetermined angle (Δθ).

One rotation for every rotation.
Therefore, the first absolute angle sensor 6 can repeatedly detect the absolute angle θ1 within the first predetermined angle range for each first predetermined angle range Δθ of the first steering shaft 2.

※ｍｏｄ（ａ，ｂ）は、ａをｂで割ったときの剰余（正の値）を示す。
となる。この第２の歯車の回転角δ１は、第２の角度センサ７０３により検出される。第２の角度センサ７０３は、第４の歯車７０２の回転角を絶対角（１回転範囲：０°〜３６０°）で検出するものが適用されている。例えば、第４の歯車７０２にＮＳ磁石を配置し、第４の歯車７０２の回転角と一致するＮＳ磁石より生じる磁力線の方向を検出するセンサや、光学的・磁気的に回転角コードを記録した部材を第４の歯車７０２と一体に回転させ、ピックアップにより回転角コードを検出するものがある。いずれのセンサを適用したとしても、第４の歯車は、第２のステアリングシャフト４が、所定の角度（Δδ）

回転する毎に１回転する。従って、第２の絶対角センサ７は、第２のステアリングシャフト４の第２の所定角度範囲Δδ毎に、第２の所定角度範囲内の絶対角δ１を繰り返し検出することができる。 The third gear 701 of the second absolute angle sensor 7 rotates integrally with the second steering shaft 4, and the rotation is transmitted to the fourth gear 702 by gear meshing. Here, assuming that the speed increasing ratio of the third gear 701 and the fourth gear 702 is G2, the rotation angle θ2 of the second gear has an angular range of 0 ° to 360 °,

* Mod (a, b) indicates a remainder (positive value) when a is divided by b.
It becomes. The rotation angle δ1 of the second gear is detected by the second angle sensor 703. As the second angle sensor 703, one that detects the rotation angle of the fourth gear 702 as an absolute angle (one rotation range: 0 ° to 360 °) is applied. For example, an NS magnet is arranged on the fourth gear 702, and a sensor for detecting the direction of the lines of magnetic force generated from the NS magnet coinciding with the rotation angle of the fourth gear 702, or a rotation angle code optically and magnetically recorded. Some members rotate a member integrally with the fourth gear 702 and detect a rotation angle code by a pickup. Regardless of which sensor is applied, the fourth steering shaft 4 has a predetermined angle (Δδ).

One rotation for every rotation. Therefore, the second absolute angle sensor 7 can repeatedly detect the absolute angle δ1 within the second predetermined angle range for each second predetermined angle range Δδ of the second steering shaft 4.

図２からも分かるように、第１の絶対角センサ６における増速比Ｇ１と第２の絶対角センサ７における増速比Ｇ２が異なっているので、位相差Δｐは、第１のステアリングシャフト２の回転に伴って変化し、その変化は、所定の角度毎に繰り返される。式６で示した位相差Δｐは、

と同等であり、位相差が３６０°変化する時の第１のステアリングシャフト２は、

回転することになる。図では、Ｇ１＝４，Ｇ２＝４．２なので、第１のステアリングシャフト２の回転幅で１８００°の範囲で位相差が一巡することになる。すなわち、第１のステアリングシャフト２の５回転毎に一巡する。 FIG. 2 shows the outputs of the first absolute angle sensor 6 and the second absolute angle sensor 7 and the phase difference between them when the sub-angle φ in the transmission ratio variable mechanism 1 is 0 °, that is, θ = δ. A calculated example is shown. At this time, the speed increase ratio G1 in the first absolute angle detection sensor 6 is 4, and the speed increase ratio in the second absolute angle detection sensor 7 is 4.2. The phase difference is calculated based on the following equation.

As can be seen from FIG. 2, since the speed increase ratio G1 in the first absolute angle sensor 6 and the speed increase ratio G2 in the second absolute angle sensor 7 are different, the phase difference Δp is equal to the first steering shaft 2. Change with the rotation of, and the change is repeated for each predetermined angle. The phase difference Δp shown in Equation 6 is

The first steering shaft 2 when the phase difference changes by 360 ° is

Will rotate. In the figure, since G1 = 4 and G2 = 4.2, the phase difference makes a round in the range of 1800 ° with the rotation width of the first steering shaft 2. That is, one round is made every five rotations of the first steering shaft 2.

となり、第１の絶対角センサ６の出力は、

となる。
また、この時、第２のステアリングシャフト４も同じだけ回転するのでθ＝δであり、さらに、Ｇ２＞Ｇ１とすると、第２の絶対角センサ７の出力は、

となる。従って、位相差Δｐ１は、式１０と式１１より、

となる。これは、第１の絶対角センサ６の１周期毎に、第１の絶対角センサ６と第２の絶対角センサ７との位相差ΔｐがΔｐ１づつ変化することを示している。よって、第１の絶対角センサ６と第２の絶対角センサ７との位相差ΔｐをΔｐ１で徐したときの商より、第１の絶対角センサ６の出力の繰り返し回数が算出できる。
図２（ｄ）に、この様子を示した。ここで、算出された前記第１の絶対角センサ６の出力の繰り返し回数をθｃ１とすると、θｃ１は、第１の絶対角センサ６の第２の歯車６０２の回転回数に相当し、また、第１の絶対角センサ６の出力は、第２の歯車６０２の回転角θ１に相当するので、第２の歯車の多回転分を含む回転角θｓ’は、

と求められる。従って、第１のステアリングシャフト２の多回転分を含む回転角θｓは、

として求められる。図２（ｆ）にこの様子を示した。図２（ｆ）に示したように、第１のステアリングシャフト２の回転角を±９００°（±２．５回転）の範囲で検出できることを示している。但し、検出可能な回転範囲は、前述したように、Ｇ１とＧ２の選び方で選択することができる。 Next, a method of calculating the number of repetitions of the first absolute angle sensor 6 from the deviation Δp will be described with reference to FIG.
FIG. 3 shows the outputs of the first absolute angle sensor 6 and the second absolute angle sensor when the first steering shaft 2 is rotated in a state where the sub rotation angle of the transmission ratio variable mechanism 1 is fixed at 0 °. Is shown.
Since the sub rotation angle of the transmission ratio variable mechanism 1 is fixed at 0 °, the rotation angle of the first steering shaft 2 and the rotation angle of the second steering shaft 4 coincide with each other as can be seen from Equation 1. ing. The output of the first absolute angle sensor 6 is rotated once after the first steering shaft 2 is rotated from 0 °.

The output of the first absolute angle sensor 6 is

It becomes.
At this time, since the second steering shaft 4 also rotates by the same amount, θ = δ, and if G2> G1, the output of the second absolute angle sensor 7 is

It becomes. Therefore, the phase difference Δp1 is obtained from the equations 10 and 11.

It becomes. This indicates that the phase difference Δp between the first absolute angle sensor 6 and the second absolute angle sensor 7 changes by Δp1 every cycle of the first absolute angle sensor 6. Therefore, the number of repetitions of the output of the first absolute angle sensor 6 can be calculated from the quotient when the phase difference Δp between the first absolute angle sensor 6 and the second absolute angle sensor 7 is gradually decreased by Δp1.
This state is shown in FIG. Here, if the calculated number of repetitions of the output of the first absolute angle sensor 6 is θc1, θc1 corresponds to the number of rotations of the second gear 602 of the first absolute angle sensor 6, and Since the output of the absolute angle sensor 1 of 1 corresponds to the rotation angle θ1 of the second gear 602, the rotation angle θs ′ including the multiple rotations of the second gear is

Is required. Therefore, the rotation angle θs including the multiple rotations of the first steering shaft 2 is

As required. This state is shown in FIG. As shown in FIG. 2 (f), the rotation angle of the first steering shaft 2 can be detected within a range of ± 900 ° (± 2.5 rotations). However, the detectable rotation range can be selected by selecting G1 and G2, as described above.

となり、第２の絶対角センサ６の出力は、

となる。従って、位相差Δｐ２は、式１６と式１５より、

となる。これは、第２の絶対角センサ７の１周期毎に、第１の絶対角センサ６と第の絶対角センサ７との位相差ΔｐがΔｐ２づつ変化することを示している。よって、第１の絶対角センサ６と第２の絶対角センサ７との位相差ΔｐをΔｐ２で徐したときの商より、第２の絶対角センサ７の出力の繰り返し回数が算出できる。図２（ｅ）には、この様子を示した。ここで、算出された前記第２の絶対角センサ７の出力の繰り返し回数をδｃ１とすると、δｃ１は、第２の絶対角センサ７の第４の歯車７０２の回転回数に相当し、また、第２の絶対角センサ７の出力は、第４の歯車の回転角δ１に相当するので、第４の歯車の多回転分を含む回転角δｓ’は、

と求められる。従って、第２のステアリングシャフト４の多回転分を含む回転角δｓは、

として求められる。図２（ｇ）にこの様子を示した。図２（ｇ）に示したように、第２のステアリングシャフト４の回転角を±９００°（±２．５回転）の範囲で検出できることを示している。但し、検出可能な回転範囲は、前述したように、Ｇ１とＧ２の選び方で選択することができる。 Next, a method of calculating the number of repetitions of the second absolute angle sensor 6 from the deviation Δp will be described with reference to FIG.
FIG. 3 shows the first absolute angle sensor 6 and the second absolute angle sensor 7 when the first steering shaft 2 is rotated with the sub rotation angle of the transmission ratio variable mechanism 1 fixed at 0 °. The output is shown. Since the sub rotation angle of the transmission ratio variable mechanism 1 is fixed at 0 °, the rotation angle of the first steering shaft 2 and the rotation angle of the second steering shaft 4 coincide with each other as can be seen from Equation 1. ing. The output of the first absolute angle sensor 7 is rotated once after the second steering shaft 4 is rotated from 0 °.

The output of the second absolute angle sensor 6 is

It becomes. Therefore, the phase difference Δp2 is obtained from the equations 16 and 15.

It becomes. This indicates that the phase difference Δp between the first absolute angle sensor 6 and the second absolute angle sensor 7 changes by Δp2 for each cycle of the second absolute angle sensor 7. Therefore, the number of repetitions of the output of the second absolute angle sensor 7 can be calculated from the quotient when the phase difference Δp between the first absolute angle sensor 6 and the second absolute angle sensor 7 is gradually reduced by Δp2. FIG. 2 (e) shows this state. Here, if the calculated number of repetitions of the output of the second absolute angle sensor 7 is δc1, δc1 corresponds to the number of rotations of the fourth gear 702 of the second absolute angle sensor 7, and Since the output of the absolute angle sensor 2 of 2 corresponds to the rotation angle δ1 of the fourth gear, the rotation angle δs ′ including the multiple rotations of the fourth gear is

Is required. Therefore, the rotation angle δs including the multiple rotations of the second steering shaft 4 is

As required. This state is shown in FIG. As shown in FIG. 2G, the rotation angle of the second steering shaft 4 can be detected within a range of ± 900 ° (± 2.5 rotations). However, the detectable rotation range can be selected by selecting G1 and G2, as described above.

  As described above, when the sub rotation angle in the transmission ratio variable mechanism 1 is 0 °, the rotation angle including the multiple rotations of the first steering shaft 2 and the rotation angle including the multiple rotations of the second steering shaft 4 are the first. The method of calculating from the first absolute angle sensor 6 and the second absolute angle sensor 7 has been described.

Next, in the transmission ratio variable mechanism 1, a process when the sub rotation angle is superimposed will be described.
FIG. 4 shows the rotation of the first steering shaft 2 (FIG. 4A) superimposed on the auxiliary rotation angle (FIG. 4B) by the transmission ratio variable mechanism 1 so that the second steering shaft 4 rotates. (FIG. 4C), the output of the first absolute angle sensor 6 (FIG. 4D), the output of the auxiliary rotation absolute angle detection means 9 (FIG. 4E), the second absolute angle. The state of the output of the sensor 7 (FIG. 3 (f)) is shown. As described above, the first absolute angle sensor 6 repeatedly outputs an absolute angle for each first predetermined angle range of the first steering shaft 2 (FIG. 4E), and the second absolute angle sensor 7 is output. Repeatedly outputs an absolute angle for each second predetermined angle range of the second steering shaft 4 (FIG. 4G), and the auxiliary rotation absolute angle detection means 9 determines the auxiliary rotation angle of the transmission ratio variable mechanism 1. An absolute angle including a multi-rotation component (FIG. 4 (f)) is output.

First, the first absolute angle calculation means 10 for calculating the rotation angle of the first steering shaft 2 will be described with reference to the flowchart of FIG. 5 and the characteristic diagram of FIG.
In step 1001, the output θ1 of the first absolute angle sensor 6 is read. In step 1002, the output δ1 of the second absolute angle sensor 7 is read. Is read. These waveforms are shown in FIGS.
In step 1004, the output δ1 of the second absolute angle sensor 7 read in step 1002 is corrected using the output φ1 of the auxiliary rotation absolute angle detection means 9 read in step 1003.

となる。すなわち、現在の回転角から、回転することになる。この回転は、第２の絶対角センサ７において、Ｇ２倍されるので、第２の絶対角センサ７の第４の歯車７０２は、回転することになる。よって、第２の角度センサ７０３は、現在の角度からた角度分回転が加わった角度を検出することになるので、

で計算される角度δ２を出力することが導かれる。このような手順で補正された第２の絶対角センサ７の補正出力を図６（ｄ）に示す。ここで、図６（ａ）に示した第１の絶対角センサ６の出力と、図６（ｄ）に示した第２の絶対角センサ７の補正出力は、伝達比可変機構１による副回転角が０°の状態と同等である。よって、ステップ１００５では式６に基づいて位相差Δｐの演算を行う。すなわち、ステップ１００５ａでは、式６（１）に基づいて、第１の絶対角センサ６の出力から、ステップ１００４にて演算された第２の絶対角センサ７の補正出力を減算する。ステップ１００５ｂでは、式６（２）に示された条件の判定を行い、条件を満足すればステップ１００５ｃに進み、ステップ１００５ａにて求めた位相差を、式６（２）に示したように修正する。ステップ１００５ｄでは、式６（３）に示された条件の判定を行い、条件を満足すればステップ１００５ｅに進み、式６（３）に示したように修正する。ステップ１００５ｂ、ステップ１００５ｄのいずれの条件も満足していなければ、式６（４）の条件であるため、ステップ１００５ａにて求めた位相差の修正を行わない。 This correction method will be described. Between the rotation angle of the first steering shaft 2, the rotation angle of the second steering shaft 4, and the sub rotation angle, there is a relationship represented by Equation 1 due to the characteristics of the transmission ratio variable mechanism 1. Accordingly, when the sub-rotation angle is set to 0 ° with the first steering shaft 2 fixed, the rotation angle δ ′ of the second steering shaft 4 is

It becomes. That is, it rotates from the current rotation angle. Since this rotation is multiplied by G2 in the second absolute angle sensor 7, the fourth gear 702 of the second absolute angle sensor 7 rotates. Therefore, since the second angle sensor 703 detects an angle that is rotated by an angle from the current angle,

It is derived to output the angle δ2 calculated by. FIG. 6D shows a correction output of the second absolute angle sensor 7 corrected by such a procedure. Here, the output of the first absolute angle sensor 6 shown in FIG. 6A and the correction output of the second absolute angle sensor 7 shown in FIG. This is equivalent to a state where the angle is 0 °. Therefore, in step 1005, the phase difference Δp is calculated based on Expression 6. That is, in step 1005a, the correction output of the second absolute angle sensor 7 calculated in step 1004 is subtracted from the output of the first absolute angle sensor 6 based on Expression 6 (1). In step 1005b, the condition shown in Expression 6 (2) is determined. If the condition is satisfied, the process proceeds to Step 1005c, and the phase difference obtained in Step 1005a is corrected as shown in Expression 6 (2). To do. In Step 1005d, the condition shown in Expression 6 (3) is determined. If the condition is satisfied, the process proceeds to Step 1005e, and the correction is made as shown in Expression 6 (3). If neither of the conditions of Step 1005b and Step 1005d is satisfied, the condition of Expression 6 (4) is satisfied, and the phase difference obtained in Step 1005a is not corrected.

ｆｌｏｏｒ（ａ，ｂ）は、ａをｂで除したときの剰余演算時の商を示す。
ここで、ａ＝ｍ×ｂ＋ｎ 但し、ｍは整数、ｎはｂと同符号。
により、第１の絶対角センサ６の繰り返し回数θｃ１が求められる。しかし、第１の絶対角センサ６の出力と第２の絶対角センサの出力に誤差がある場合、位相差ｐ１にも誤差が伝搬する。この誤差を含んだ状態で、式２２に基づいて第１の絶対角センサ６の繰り返し回数を求めると、繰り返し回数に誤差が生じ、第１のステアリングシャフト２の検出回転角にも誤差が生じる。 In step 1006, the number of repetitions of the first absolute angle sensor 6 is obtained based on the phase difference p1 obtained in step 1005. In step 1006a, the quotient obtained by dividing the phase difference p1 by Δp1 based on Equation 12

floor (a, b) indicates a quotient at the time of remainder calculation when a is divided by b.
Here, a = m × b + n where m is an integer and n has the same sign as b.
Thus, the number of repetitions θc1 of the first absolute angle sensor 6 is obtained. However, if there is an error between the output of the first absolute angle sensor 6 and the output of the second absolute angle sensor, the error also propagates to the phase difference p1. When the number of repetitions of the first absolute angle sensor 6 is obtained based on Expression 22 in a state including this error, an error occurs in the number of repetitions, and an error also occurs in the detected rotation angle of the first steering shaft 2.

という、剰余演算を行う。 This is shown in FIG. 9 and FIG. As can be seen from the figure, when there is an error, the detected rotation angle of the first steering shaft 2 is not convex as shown in FIG. 9 (f) A or concave as shown in FIG. 11 (f) A. An accurate detection angle appears. The cause of this phenomenon will be described with reference to FIGS. FIG. 10 is a diagram for explaining the convex factor. 10A shows the output θ1 of the first absolute angle sensor 6, and FIG. 10B shows the calculation result θc1 of step 1006a based on Equation 22. As can be seen from the figure, the signal of θc1 changes in FIG. 10A1 part {FIG. 10 (b)}. However, θc1 must change in synchronism with the transition of the output θ1 of the first absolute angle sensor 6 from 0 to 360 ° or from 360 ° to 0 °, that is, in FIG. 10A2. Therefore, between the A1 part and the A2 part in FIG. 10, θc1 is 1 larger than the correct value. Therefore, when the rotation angle including the multiple rotations of the first steering shaft 2 is calculated according to the equation 14, an incorrect angle is output in a convex shape as shown in FIG. Next, a procedure for correcting this error will be described. In FIG. 5 step 1006b,

The remainder operation is performed.

ａｂｓ（）は、絶対値演算を表す。
式２４は、図５のフローチャートにおいて、ステップ１００６ｃ及び、ステップ１００６ｄに相当し、ステップ１００６ｃにおいて式２４（１）による判定を行い、ステップ１００６ｃで条件が満たされれば、ステッププ１００６ｄに進み、式２４（２）に示したように、ステップ１００６ａにて演算された繰り返し回数θｃ１を減算することで正しい値に補正する。 FIG. 10C shows the result θmod of the remainder calculation. As can be seen from FIG. 10B and FIG. 10C, θ mod in step 1006c becomes 0 in the A1 portion where θc1 in step 1006b changes. Further, between the A1 portion where θc1 changes in Step 1006b and the A2 portion where the output θ1 of the first absolute angle sensor 6 changes from 360 ° to 0 °, the absolute value of θmod in Step 1006b is small, and the first The output θ1 of the absolute angle sensor 6 is in the vicinity of 360 °, and θc1 in step 1006a is a value one larger than the accurate value. After the portion A2 where the output θ1 of the first absolute angle sensor 6 transitions from 360 ° to 0 °, θc1 in step 1006a is an accurate value.
Therefore, the range from the A1 part to the A2 part can be determined by θmod and θ1, and specifically, the calculation result θc1 in step 1006a is corrected according to the following equation.

abs () represents an absolute value calculation.
In the flowchart of FIG. 5, Expression 24 corresponds to Step 1006c and Step 1006d. In Step 1006c, the determination according to Expression 24 (1) is performed. If the condition is satisfied in Step 1006c, the process proceeds to Step 1006d and Expression 24 ( As shown in 2), the value is corrected to a correct value by subtracting the number of repetitions θc1 calculated in step 1006a.

式２５は、図５のフローチャートにおいて、ステップ１００６ｅ及び、ステップ１００６ｆに相当し、ステップ１００６ｅにおいて式２５（１）による判定を行い、ステップ１００６ｅで条件が満たされれば、ステップ１００６ｆに進み、式２５（２）に示したように、ステップ１００６ａにて演算された繰り返し回数θｃ１を加算することで、正しい値に補正する。ステップ１００７では、式１４に基づいて第１のステアリングシャフト２の回転角θｓ１が算出され、この様子を図６（ｇ）に示す。
以上の手順を所定時間毎に繰り返すことにより、連続的にステアリングシャフト２の多回転分を含む回転角θを検出することが可能となる。また、検出された回転角θ（＝θｓ１）の角度分解能は、式１４からも分かるように、第１の絶対角センサ６の第１の角度センサ６０３の角度分解能の１／Ｇ１となるため、細かく検出できる特徴もある。 Next, the concave factor shown in FIG. 11 will be described with reference to FIG.
As can be seen from FIGS. 12A and 12B, in the A1 portion where the output of the first absolute angle sensor 6 changes from 360 ° to 0 °, the number of repetitions θc1 in step 1006a does not change, and A2 It varies by part. (FIG. 12 (b)) Accordingly, since the number of repetitions θc1 in step 1006a is 1 smaller than the accurate value in the range from the A1 portion to the A2 portion, the multiple number of rotations of the first steering shaft 2 according to the equation (14). When the rotation angle including is calculated, an incorrect angle is output in a concave shape as shown in FIG. 11A. In the range from the A1 part to the A2 part, the absolute value of the result of the remainder calculation θmod shown in Expression 23 is large (FIG. 12C), and the output of the first absolute angle sensor 6 is in the vicinity of 0 °. Therefore, the range from the A1 part to the A2 part can be determined by θmod and θ1, and specifically, the calculation result θc1 in step 1006a is corrected according to the following equation.

In the flowchart of FIG. 5, Expression 25 corresponds to Step 1006e and Step 1006f. In Step 1006e, the determination by Expression 25 (1) is performed. If the condition is satisfied in Step 1006e, the process proceeds to Step 1006f, and Expression 25 ( As shown in 2), the number of repetitions θc1 calculated in step 1006a is added to correct the value. In Step 1007, the rotation angle θs1 of the first steering shaft 2 is calculated based on Expression 14, and this state is shown in FIG.
By repeating the above procedure every predetermined time, it is possible to continuously detect the rotation angle θ including the multiple rotations of the steering shaft 2. Further, since the angular resolution of the detected rotation angle θ (= θs1) is 1 / G1 of the angular resolution of the first angle sensor 603 of the first absolute angle sensor 6 as can be seen from Equation 14, There is also a feature that can be detected in detail.

となる。すなわち、現在の回転角から、回転することになる。この回転は、第１の絶対角センサ６において、Ｇ１倍されるので、第１の絶対角センサ６の第２の歯車６０２は、回転することになる。よって、第１の角度センサ６０３は、現在の角度から角度分回転が加わった角度を検出することになるので、

で計算される角度θ２を出力することが導かれる。 Next, a second absolute angle calculation means for calculating the rotation angle of the second steering shaft 4 will be described with reference to the flowchart of FIG. 7 and the characteristic diagram of FIG. In step 1101, the output θ1 of the first absolute angle sensor 6 is read. In step 1102, the output δ1 of the second absolute angle sensor 7 is read. In step 1103, the output φ1 of the sub-rotation absolute angle detection means is obtained. Is read.
These waveforms are shown in FIGS. In step 1104, the output θ1 of the first absolute angle sensor 6 read in step 1101 is corrected using the sub rotation read in step 1103 or the output φ1 of the absolute angle detection means 9.
This correction method will be described. Between the rotation angle of the first steering shaft 2, the rotation angle of the second steering shaft 4, and the sub rotation angle, there is a relationship represented by Equation 1 due to the characteristics of the transmission ratio variable mechanism 1. Therefore, when the secondary rotation angle is set to 0 ° with the second steering shaft 4 fixed, the rotation angle θ ′ of the first steering shaft 2 is

It becomes. That is, it rotates from the current rotation angle. Since this rotation is multiplied by G1 in the first absolute angle sensor 6, the second gear 602 of the first absolute angle sensor 6 rotates. Therefore, the first angle sensor 603 detects an angle that is rotated by an angle from the current angle.

It is derived to output the angle θ2 calculated by

ｆｌｏｏｒ（ａ，ｂ）は、ａをｂで除したときの剰余演算時の商を示す。
ａ＝ｍ×ｂ＋ｎ 但し、ｍは整数、ｎは、ｂと同符号である。
で算出されるが、上記で説明した第１のステアリングシャフト２の回転角を算出した場合と同様に、第１の絶対角センサ６の出力と第２の絶対角センサの出力に誤差がある場合、位相差ｐ２にも誤差が伝搬し、凸状の図９Ｂ部及び、凹状の図１１Ｂ部に示すような誤差が生じる。この誤差が生じる原因も図１０Ｂ１部、Ｂ２部、図１２Ｂ１部、Ｂ２部に示したように同等である。よって、式２８にて求めた繰り返し回数δｃ１を、

で示される剰余演算結果と、第２の絶対角センサ７の出力δ１を用い、

に従って、図１０Ｂ１部からＢ２部の範囲を判定して補正する。さらに、

に従って、図１２Ｂ１部からＢ２部の範囲を判定して補正する。 FIG. 8D shows the correction output of the first absolute angle sensor 6 corrected by such a procedure. Here, the correction output of the first absolute angle sensor 6 shown in FIG. 8D and the output of the second absolute angle sensor 7 shown in FIG. This is equivalent to a state where the angle is 0 °. Therefore, the phase difference Δp is calculated in step 1105 (1105a, 1105b, 1105c, 1105d, 1105e) based on Expression 6. The phase difference p2 obtained in this way is shown in FIG. In step 1106, the number of repetitions δc1 of the second absolute angle sensor 7 is obtained. The number of repetitions δc1 is basically a quotient obtained by dividing the phase difference p2 by Δp2 based on Equation 17.

floor (a, b) indicates a quotient at the time of remainder calculation when a is divided by b.
a = m × b + n where m is an integer and n has the same sign as b.
As in the case of calculating the rotation angle of the first steering shaft 2 described above, there is an error between the output of the first absolute angle sensor 6 and the output of the second absolute angle sensor. The error also propagates to the phase difference p2, and an error as shown in the convex part of FIG. 9B and the concave part of FIG. 11B occurs. The causes of this error are the same as shown in FIG. 10B1, B2, FIG. 12B1, and B2. Therefore, the number of repetitions δc1 obtained by Equation 28 is

And the output δ1 of the second absolute angle sensor 7,

Accordingly, the range from the B1 part to the B2 part in FIG. 10 is determined and corrected. further,

Accordingly, the range from the B1 part to the B2 part in FIG. 12 is determined and corrected.

That is, in step 1106a in FIG. 7, the number of repetitions δc1 is calculated based on Expression 28, and in step 1106b, a remainder calculation is performed based on Expression 29. In step 1106c, it is determined whether to correct the number of repetitions δc1 according to Expression 30 (1). In step 1106e, it is determined whether or not the number of repetitions δc1 is corrected according to the equation 31 (1).
The number of repetitions δc1 of the second absolute angle sensor 7 is obtained by the above procedure. FIG. 8F shows δc1 obtained in this way. In step 1107, the rotation angle δs2 of the second steering shaft 4 is calculated based on Expression 19, and this is shown in FIG.
By repeating the above procedure every predetermined time, it is possible to continuously detect the rotation angle δ (= δs2) including the multiple rotations of the steering shaft 4. Further, as can be seen from the equation 17, the angular resolution of the detected rotation angle δ is 1 / G2 of the angular resolution of the second angle sensor 703 of the second absolute angle sensor 7, so that it can be detected finely. There is also.

で算出され、第２のステアリングシャフト４の回転角δを上記に基づいて算出δｓ２した場合は、第１のステアリングシャフト２の回転角θは

で求めることが可能である。 In the above description, the rotation angle θs including the multiple rotations of the first steering shaft 2 and the rotation angle δs including the multiple rotations of the second steering shaft 4 are independently calculated. May be calculated based on Equation (1) and the other may be calculated based on Equation (1). That is, when the rotation angle θ of the first steering shaft 2 is calculated based on the above θs1, the rotation angle δ of the second steering shaft 4 is

And the rotation angle δ of the second steering shaft 4 is calculated δs2 based on the above, the rotation angle θ of the first steering shaft 2 is

It is possible to ask for.

  As described above, in order to detect the absolute angle including the multiple rotations of the first steering shaft 2 and the second steering shaft 4 from the start of the control system, the auxiliary rotation absolute angle detection means 9 includes: It is necessary to be able to detect the absolute angle including multiple rotations from the start. That is, if the sub-rotation absolute angle detection means 9 cannot detect an absolute angle including multiple rotations from the time of activation, the output of the first absolute angle sensor 6 or the second absolute angle sensor 7 is sub-rotation absolute. This is because correction cannot be performed using the output of the corner detection means 9. Hereinafter, the sub rotation absolute angle detection means 9 will be described.

  When the transmission ratio variable mechanism 1 is not controlled (for example, when the vehicle IG is turned off), if the sub-rotation angle can be freely rotated, the sub-rotation angle does not change even if the steering wheel 1 is steered. Since it rotates with the steering, the 2nd steering shaft 4 connected to the steering mechanism 5 which steers a steered wheel cannot be rotated. That is, it means that the steering wheel cannot be steered by the steering of the handle 1. Therefore, when the transmission ratio variable mechanism 1 is not controlled, the driving means 8 rotates with respect to the rotation input from the first steering shaft 2 or the second steering shaft 4 so that the sub rotation angle does not freely rotate. Such as a mechanism having a so-called self-locking property using a worm gear or the like, or when the transmission ratio variable mechanism 1 is not controlled, the auxiliary rotation angle for mechanically prohibiting the rotation of the driving means 8 Limiting means are provided. That is, the transmission ratio variable mechanism 1 is configured such that the sub rotation angle hardly changes when the transmission ratio variable mechanism 1 is not controlled.

にて検出することができる。この駆動手段８の回転角を多回転分も含めた絶対角φＭを検出する方法として、第１の絶対角センサ６、第２の絶対角センサ７と同様に、駆動手段８の回転角の所定角度範囲内の絶対角を繰り返し検出するものが適用可能である。図１３に、その概略構成を示す。 Next, details of the sub-rotation absolute angle detection means 9 will be described. In the transmission ratio variable mechanism 1, the sub rotation angle is superimposed by the driving means 8. The drive means 8 is mainly composed of an electric motor, but the rotation angle of the drive means 8 and the sub-rotation angle actually superimposed by the transmission ratio variable mechanism 1 are determined by the configuration of the transmission ratio variable mechanism 1. There exists a reduction ratio Gs. That is, if the absolute angle including the rotation angle of the driving means 8 including multiple rotations is φM, the sub-rotation angle φ actually superimposed by the transmission ratio variable mechanism 1 is

Can be detected. As a method of detecting the absolute angle φM including the rotation angle of the drive means 8 including multiple rotations, the predetermined rotation angle of the drive means 8 is determined in the same manner as the first absolute angle sensor 6 and the second absolute angle sensor 7. A device that repeatedly detects an absolute angle within an angle range is applicable. FIG. 13 shows a schematic configuration thereof.

Next, the operation of the sub rotation absolute angle detecting means 9 will be described with reference to the flowchart of FIG. 14 and the characteristic diagram of FIG. When control is started, processing is started from step 901. In step 902, the sub rotation repetition count end value of the sub rotation angle sensor 901 held in the storage means 903 when the control is completed is called, and the initial value φc of the sub rotation angle repetition count value is set. This φc is a value when the time of FIG. 15C is zero.
In step 903, the sub rotation angle end value held in the storage means 903 is called, and the sub rotation angle previous detection value φsb is set. In step 904, the output φs of the sub rotation angle sensor 901 is read. This φs is output in the range of 0 to 360 ° for each rotation of the drive unit 8 when the rotation angle of the drive unit 8 changes as shown in FIG. 15A, and has a waveform as shown in FIG. It becomes. In FIG. 15, the output of the sub rotation angle sensor 902 assumes one rotation of the driving means 8 as one cycle.

但し、ｎは、駆動手段８の１回転当たりの、副角度センサ９０１の繰り返し回数
にて算出する。この算出された駆動手段８の回転角を図１５（ｄ）に示す。ステップ９１０では、ステップ９０９にて算出した駆動手段８の回転角φＭと、伝達比可変機構１の構成により決定される駆動手段８の回転角と重畳される副回転角φとの関係である式２８を用いて、

にて算出される。 Steps 905 to 908 are processes for counting the number of repetitions of the output of the sub rotation angle sensor 901.
In step 905, the sub-rotation repetition count value is counted up. That is, the sub rotation repetition count value needs to be counted up when the output of the sub rotation angle sensor 901 transitions from 360 ° to 0 °, so that the previous value φsb of the sub rotation angle sensor 901 is equal to or greater than the predetermined value φHth. If the current value φs of the sub rotation angle sensor 901 read in step 904 is equal to or smaller than the predetermined value φLth, it is determined that the output of the sub rotation angle sensor 901 has transitioned from 360 ° to 0 °, and step 906 is performed. Advancing and counting up the sub rotation angle repetition count value. In step 907, the sub-rotation repetition frequency count value is counted down. That is, the sub-rotation repetition count value countdown needs to be performed when the output of the sub-rotation angle sensor 901 transitions from 0 ° to 360 °, so that the previous value φsb of the sub-rotation angle sensor 901 is equal to or less than the predetermined value φLth, If the current value φs of the sub rotation angle sensor 901 read in step 904 is equal to or greater than the predetermined value φHth, it is determined that the output of the sub rotation angle sensor 901 has shifted from 0 ° to 360 °, and the process proceeds to step 908. The sub rotation angle repeat count value is counted down.
Here, the predetermined values φHth and φLth are appropriately set according to the maximum rotation speed of the driving unit 8 and the processing period so that the count-up or count-down is not mistakenly performed. The output of the sub rotation angle repetition counting means is shown in FIG.
In step 909, the rotation angle φM of the driving means 8 is determined from the output φs of the sub rotation angle sensor 901 read in step 904 and the sub rotation repetition count value φc counted in steps 905 to 908.

However, n is calculated by the number of repetitions of the sub-angle sensor 901 per one rotation of the driving unit 8. The calculated rotation angle of the driving means 8 is shown in FIG. In step 910, an equation representing the relationship between the rotation angle φM of the driving means 8 calculated in step 909 and the auxiliary rotation angle φ superimposed on the rotation angle of the driving means 8 determined by the configuration of the transmission ratio variable mechanism 1. 28,

It is calculated by.

The calculated sub rotation angle φ1 is shown in FIG.
In this way, the rotation angle of the first steering shaft 2 and the rotation angle of the second steering shaft 4 are calculated according to the above procedure using the detected sub rotation angle φ1.
In step 911, the output φs of the sub rotation angle sensor 901 read in step 904 is recorded as the previous value φsb used in the next sub rotation angle calculation. In step 912, it is determined whether or not the control is completed. If the control is being performed, the process proceeds to step 904, and the sub rotation angle φ1 is continuously calculated by repeating the calculation of the sub rotation angle φ1 every predetermined time. Is calculated.
On the other hand, when the control is completed, the process proceeds to step 913, where it is determined whether the drive unit 8 stops driving the transmission ratio variable mechanism 1. That is, it is determined whether inertial rotation or the like of the drive unit 8 is stopped, or completion of the sub rotation angle limitation by the sub rotation angle limitation unit 12 is completed. While the drive unit 8 is rotating, the process proceeds to step 904, and the calculation of the sub rotation angle φ1 is continued until the rotation stops.
If it is determined that the sub rotation angle is stopped, the process proceeds to step 914, where the sub rotation angle repetition count value φc is stored. The stored sub rotation repetition count value φc is read in step 902 when the control is resumed. Similarly, in step 915, the sub rotation angle sensor output φs is stored. The stored auxiliary rotation angle sensor output φs is called at step 903 when the control is resumed and used as the previous output value of the auxiliary rotation angle sensor 901.
The sub rotation angle repetition count value φc and the sub rotation angle sensor output φs are stored in an EEPROM or a flash ROM that can be electrically erased / written and can store values without a power source.

Next, a case where a so-called incremental encoder (rotary encoder) is applied to the sub rotation angle sensor 9 will be described.
The incremental encoder outputs two pulses having a phase difference of 90 °, and is configured to detect an angle by counting up or counting down a count value depending on the state of the pulse. FIG. 16 shows an outline of the operation.
16 (a) and 16 (b) show two pulse trains that are 90 ° out of phase, and when the A phase (a) or B phase (b) changes, the direction of the change and the other level Accordingly, the angle is relatively counted as shown in FIG. 16C by counting up or down based on the truth table of FIG. The angle is obtained by multiplying the count value by the angle per count of the encoder.
As described above, since the encoder relatively counts the angle, it cannot count the absolute value of the angle alone.

FIG. 17 shows a flowchart when this encoder is applied to the sub-rotation absolute angle detecting means 9.
In FIG. 17, the process is started from step 951. In step 952, the sub rotation angle count value φe stored at the end of the previous control is read. As described above, the sub-rotation angle hardly rotates when it is not controlled, but includes some errors due to backlash of the sub-rotation angle limiting means 12. In step 953, the sub rotation angle φ1 to be superimposed is calculated by dividing the stored sub rotation angle φe by the gear ratio Gs determined by the characteristics of the transmission ratio variable mechanism 1. In step 954, the first absolute angle calculation process is performed using the auxiliary rotation angle φ1, and the absolute angle θs including the multiple rotations of the first steering shaft 2 is calculated.
Similarly, in step 955, the absolute angle δs including the multiple rotations of the second steering shaft 4 is calculated. In these two processes, the error of the sub rotation angle φ1 is calculated only by the calculation using the sub rotation angle φ1, for example, the calculation of the number of repetitions of the first angle sensor 603 in the first absolute angle sensor process. And is not directly used for calculating the absolute angle δs. That is, there is no problem as long as the error of the auxiliary rotation angle φ1 does not affect the process of calculating the number of repetitions, and the absolute angle θs including the multiple rotations of the first steering shaft 2 and the second steering shaft are accurate. That is, the absolute angle δs including four multi-rotations is calculated.

In step 956, an accurate sub rotation absolute angle φ 1 is calculated based on Equation 1. In step 957, the gear ratio Gs is multiplied to calculate an accurate auxiliary rotation angle φe, and the count value is reset to this value. In step 958, the above-described phase counting process is performed, and an accurate sub rotation angle φe is counted with the rotation of the sub rotation angle. Here, although the phase counting process has been described as a process on the flowchart for the sake of explanation, it may be performed by H / W (hardware). When counting by H / W, step 958 is a process of reading the count value from the phase count H / W. In step 959, the sub rotation absolute angle superimposed by the transmission ratio variable mechanism 1 is calculated by dividing the counted sub rotation angle φ1 by the gear ratio Gs. Using the sub rotation absolute angle φ1 thus calculated, the rotation angle of the first steering shaft 2 and the rotation angle of the second steering shaft 4 are calculated according to the above procedure.
In step 960, it is determined whether or not the control is finished. If the control is being performed, the process proceeds to step 958, and the sub rotation angle φ1 is continuously calculated by repeating the calculation of the sub rotation angle φ1 every predetermined time. Is calculated.
Here, when the phase counting process (step 958) is performed by S / W (software), the predetermined time needs to be equal to or shorter than the shortest time during which the pulse changes so that there is no counting omission in the phase counting process (step 958). There is.

On the other hand, when the control is completed, the process proceeds to step 961 to determine whether or not the drive unit 8 stops driving the transmission ratio variable mechanism 1. That is, it is determined whether inertial rotation or the like of the drive unit 8 is stopped, or completion of the sub rotation angle limitation by the sub rotation angle limitation unit 12 is completed.
While the drive unit 8 is rotating, the process proceeds to step 958, and the calculation of the sub rotation angle φ1 is continued until the rotation stops. If it is determined that the sub rotation angle is stopped, the process proceeds to step 959, and the sub rotation angle φe is stored. The stored sub rotation angle φe is read in step 952 when the control is resumed.
The sub rotation angle φe is stored in an EEPROM or a flash ROM that can be electrically erased / written and can store a value without a power source.

  According to the first embodiment, even if the steering wheel is steered at the time of non-control, the absolute angle including the multiple rotations of the first steering shaft and the second steering shaft from the time when the sensor system is started is set to the first angle. The absolute angle sensor, the second absolute angle sensor, and the sub-rotation absolute angle detection means can be used for detection.

Embodiment 2. FIG.
FIG. 18 is a block diagram showing a transmission ratio variable mechanism sensor system according to Embodiment 2 of the present invention.
FIG. 18 is different from Embodiment 1 in the method of calculating the absolute angle of the first steering shaft 2 and the method of calculating the absolute angle of the second steering shaft 4.
In FIG. 18, the third absolute angle calculation means 13 receives the outputs of the first angle sensor 6, the second angle sensor 7, and the auxiliary rotation absolute angle detection means 9 as in the first embodiment. The absolute angle including the multiple rotations of the rotation angle of the first steering shaft 2 is output. As in the first embodiment, the fourth absolute angle calculation means 14 receives the outputs of the first angle sensor 6, the second angle sensor 7, and the auxiliary rotation absolute angle detection means 9, The absolute angle including the rotation angle of the steering shaft 4 including multiple rotations is output.

FIG. 19 is a flowchart showing the operation of the third absolute angle calculation means of the transmission ratio variable mechanism sensor system according to Embodiment 2 of the present invention.
FIG. 20 is an explanatory diagram showing a method of counting the number of repetitions of the third absolute angle calculating means of the sensor system for variable transmission ratio mechanism according to Embodiment 2 of the present invention.
FIG. 21 is a flowchart showing the operation of the fourth absolute angle calculating means in the transmission ratio variable mechanism sensor system according to Embodiment 2 of the present invention.

First, the 3rd absolute angle detection means 13 is demonstrated based on the flowchart shown in FIG.
The flowchart of FIG. 19 is roughly divided into an initialization part from step 1301 to step 1306 and a processing loop from step 1312 to step 1318.
The initialization part of steps 1301 to 1306 is the output of the first absolute angle sensor 6, the second absolute angle sensor 7, and the auxiliary rotation absolute angle detection means 9 at the start of control, as in the first embodiment. Thus, the number of repetitions θc2 of the first absolute angle sensor 6 is calculated. (Step 1306) In step 1307, the value θ1 of the first absolute angle sensor 6 read in step 1301 is recorded and becomes the previous value θ1b. In step 1308, the value θ1 of the first absolute angle sensor 6 is read and set as the current value θ1.
In steps 1309 to 1311, the current value θ1 of the first absolute angle sensor 6 read in step 1308 and the previous value θ1b of the first absolute angle sensor 6 recorded in step 1307 or step 1314 described later. And the number of repetitions θc2 of the first absolute angle sensor 6 is counted.
The counting method will be described with reference to FIG. As shown in FIG. 20, the number of repetitions θc2 of the first absolute angle sensor 6 is counted up when the output θ1 of the first absolute angle sensor 6 transitions from 360 ° to 0 °. It is necessary to count down when transitioning to 360 °.

にて算出する。ステップ１３１４では、次回の検出のため、ステップ１３０８にて読み込んだ第１の絶対角センサ６の今回値θ１を、次回の前回値θ１ｂとして記録し、ステップ１３１２にループする。このステップ１３１２〜ステップ１３１８までの処理を、所定時間毎に繰り返すことにより、連続的且つ、第１の絶対角センサ６の出力のみで、第１のステアリングシャフト２の多回転分も含めた絶対角θ（＝θｓ３）を検出する。 Step 1309 in FIG. 19 determines that the output θ1 of the first absolute angle sensor 6 has transitioned from 360 ° to 0 °. That is, if the previous value θ1b of the absolute angle sensor 6 is equal to or larger than θHth and the current value θ1 of the absolute angle sensor 6 is equal to or smaller than θLth, the process proceeds to step 1310 on the assumption that a transition has occurred from 360 ° to 0 °, and the number of repetitions θc2 is counted up. This is points (a) and (b) in FIG.
Similarly, in step 1311, it is determined that the output θ1 of the first absolute angle sensor 6 has transitioned from 0 ° to 360 °. That is, if the previous value θ1b of the absolute angle sensor 6 is equal to or smaller than θLth and the current value θ1 of the absolute angle sensor 6 is equal to or greater than θHth, it is determined that a transition has occurred from 0 ° to 360 °, and the process proceeds to step 1312 and the number of repetitions θc2 is counted down. This is points (c) and (d) in FIG.
If the above conditions are not satisfied, the number of repetitions θc2 does not change. In step 1317, the number of repetitions θc2 thus counted, the output θ1 of the first absolute angle sensor 6, the rotation angle of the first steering shaft 2, and the detection angle of the first absolute angle sensor 6 are gears. Using the ratio G1, the absolute angle θ including the multiple rotations of the rotation angle of the first steering shaft 1 is

Calculate with In step 1314, for the next detection, the current value θ1 of the first absolute angle sensor 6 read in step 1308 is recorded as the next previous value θ1b, and the process loops to step 1312. By repeating the processing from step 1312 to step 1318 every predetermined time, the absolute angle including the multiple rotations of the first steering shaft 2 continuously and only by the output of the first absolute angle sensor 6. θ (= θs3) is detected.

Next, the operation of the fourth absolute angle calculation means 14 will be described using the flowchart of FIG.
The operation of the fourth absolute angle calculation means 14 is the same as the operation of the third absolute angle calculation means 13, and the first absolute angle sensor 6, the second absolute angle sensor 7, and the auxiliary rotation absolute angle detection at the start of control. From the means 9, the initialization part (step 1401 to step 1407) for setting the initial value of the number of repetitions δc2 of the second absolute angle sensor 7, the previous value δ1b and the current value δ1 of the second absolute angle sensor 7, A processing loop that counts the number of repetitions δc2 and repeatedly calculates an absolute angle δs4 including multiple rotations of the second steering shaft 2 every predetermined time from the number of repetitions δc2 and the output δ1 of the second absolute angle sensor 7 (step 1408) To Step 1414).
Therefore, similarly to the third absolute angle calculation means, the absolute angle δ (= δs4) including the multiple rotations of the second steering shaft 4 is detected only by the output of the second absolute angle sensor 7.

According to the second embodiment, even if the steering wheel is steered during non-control, immediately after the sensor system is started, the absolute angle including the multiple rotations of the first steering shaft is set to the first absolute angle sensor and the second absolute angle sensor. It can be detected by three absolute angle sensors and sub-rotation absolute angle detection means, and thereafter can be detected by one first absolute angle sensor.
Further, even when the steering wheel is steered at the time of non-control, immediately after the sensor system is started, the absolute angle including the multiple rotations of the second steering shaft is set to the first absolute angle sensor, the second absolute angle sensor, and the auxiliary rotation. It can be detected by three of the absolute angle detecting means, and thereafter can be detected by one second absolute angle sensor.

Embodiment 3 FIG.
FIG. 22 is a block diagram showing a transmission ratio variable mechanism sensor system according to Embodiment 3 of the present invention.
In FIG. 22, 1 to 11, 601 to 603, and 701 to 703 are the same as those in FIG. 1, and 13, 14 are the same as those in FIG.
22A shows a sensor system for a variable transmission ratio mechanism similar to FIG. 1, and FIG. 22B shows a portion of the variable transmission ratio mechanism 1. FIG. In FIG. 22B, absolute angle sensors 604 and 704 of a type that directly detect the rotation angle of the steering shaft are provided. The absolute angle sensor 604 and the absolute angle sensor 704 are sensors having the same specifications.

FIG. 23 is a diagram illustrating detection characteristics of the first absolute angle sensor and the second absolute angle sensor of the sensor system for the transmission ratio variable mechanism according to Embodiment 3 of the present invention.
In FIG. 23, the horizontal axis represents the first steering shaft rotation angle (°).
23A shows the rotation angle (°), FIG. 23B shows the first absolute angle sensor output (°), and FIG. 23C shows the first absolute angle sensor output (°). It is.

FIG. 24 is an explanatory diagram of a method for detecting the absolute angles of the first and second steering shafts of the sensor system for the variable transmission ratio mechanism according to the third embodiment of the present invention.
In FIG. 24, the horizontal axis represents the first steering shaft rotation angle (°). 24 (a) to 24 (c), 24 (f), and 24 (g) are the respective output values (°), and FIGS. 24 (d) and 24 (e) are the number of times. It is.
24A shows the first absolute angle sensor output, FIG. 24B shows the second absolute angle sensor output, and FIG. 24C shows the first absolute angle sensor output and the second absolute angle. FIG. 24D shows a first iteration count calculation value, FIG. 24E shows a second iteration count calculation value, FIG. 24F shows a first steering shaft rotation angle calculation value, FIG. FIG. 24G shows a second steering shaft rotation angle calculation value.

FIG. 25 is a flowchart showing the operation of the first absolute angle calculation means of the transmission ratio variable mechanism sensor system according to Embodiment 3 of the present invention.
FIG. 26 is a flowchart showing the operation of the second absolute angle calculating means of the sensor system for variable transmission ratio mechanism according to the third embodiment of the present invention.

で表される。
よって、図２３（ａ）に示したように、副回転角φを０°に固定した状態で、第１のステアリングシャフト２を回転させると、第２のステアリングシャフト４の回転角δは、式３８に示されたＧ倍される。このことより、実施の形態１、実施の形態２では、第１の絶対角センサ６内の増速比Ｇ１と、第２の絶対角センサ７内の増速比Ｇ２を異ならせていたのに対し、実施の形態３では、第１の絶対角センサ６内の増速比と第２の絶対角センサ７内の増速比を同じにしても良い。
このように同じにした時の第１絶対角センサ６と第２の絶対角センサ７の出力の様子を、図２３（ｂ）、図２３（ｃ）に示した。 In the third embodiment, the characteristics of the transmission ratio variable mechanism 1 are different from those in the first and second embodiments. That is, in the first embodiment, the relationship between the rotation angle θ of the first steering shaft 2, the rotation angle δ of the second steering shaft 4, and the auxiliary rotation angle φ superimposed by the driving means 8 is expressed by Equation 1. On the other hand, in the third embodiment,

It is represented by
Therefore, as shown in FIG. 23A, when the first steering shaft 2 is rotated in a state where the sub rotation angle φ is fixed at 0 °, the rotation angle δ of the second steering shaft 4 is expressed by the equation It is multiplied by G shown in 38. Thus, in the first and second embodiments, the speed increase ratio G1 in the first absolute angle sensor 6 is different from the speed increase ratio G2 in the second absolute angle sensor 7. On the other hand, in the third embodiment, the speed increasing ratio in the first absolute angle sensor 6 and the speed increasing ratio in the second absolute angle sensor 7 may be the same.
FIGS. 23B and 23C show the output states of the first absolute angle sensor 6 and the second absolute angle sensor 7 when they are the same in this way.

Further, since the speed increasing ratio in the first absolute angle sensor 6 and the speed increasing ratio in the second absolute angle sensor 7 may be the same G3, as schematically shown in FIG. Absolute angle sensors 604 and 704 of a type that directly detect the rotation angle of the steering shaft may be used without detecting the angle by increasing the speed with a gear. In this case, a member that records an absolute angle code on the steering shaft and reads the code (so-called absolute encoder), or a ring magnet that is attached to the steering shaft and detects the absolute angle using a magnetic sensor is there.
At this time, the number of repetitions of absolute angle detection per one rotation of the steering shaft corresponds to the speed increasing ratio G3 in the absolute angle sensors 6 and 7.
By using such an absolute angle sensor, it is not necessary to attach a gear member, and by integrating the absolute angle sensor integrally with a bearing that supports the steering shaft to be rotated, the number of parts can be reduced and the assembly can be improved. Is possible.

Next, a method for calculating the rotation angles of the first steering shaft 2 and the second steering shaft 4 will be described with reference to the description of the first embodiment.
FIG. 24 shows a state where the first steering shaft 2 is rotated with the sub rotation angle φ fixed at 0 ° in the transmission ratio modification mechanism 1. FIG. 24A shows the output of the first absolute angle sensor 6, and FIG. 24B shows the output of the second absolute angle sensor 7.
This figure also shows that the ratio G of the rotation angle of the second steering shaft to the rotation angle of the first steering shaft 2 in the transmission ratio variable mechanism 1 is G = 1.05, and the acceleration of the steering shaft and each absolute angle sensor The ratio G3 is G3 = 4.
Therefore, the speed increase ratio of the first absolute angle sensor with respect to the rotation angle of the first steering shaft 2 is 4, and the speed increase ratio of the second absolute angle sensor with respect to the rotation angle of the first steering shaft 2 is G × G3 = 1.05 × 4 = 4.2. That is, the output of the first absolute angle sensor 6 and the output of the second absolute angle sensor 7 with respect to the rotation angle of the first steering shaft 2 are the same as those shown in FIG. 2A and FIG. Same as (b). Therefore, the number of repetitions of the first angle sensor 6 and the number of repetitions of the second angle sensor can be calculated in the same manner from the phase difference between the output of the first angle sensor 6 and the output of the second absolute angle sensor. It becomes possible.

を代入して、

で得られるΔｐ３で、位相差を徐すことで、第１の絶対角センサ６の繰り返し回数θｃ１を算出することができる。この繰り返し回数θｃ１の算出例を、図２４（ｄ）に示す。従って、実施の形態１と同様に、第１のステアリングシャフト１の多回転分を含む回転角度θは、

にて算出ができる。このようにして算出した第１のステアリングシャフトの回転角を図２４（ｆ）に示す。 FIG. 24C shows the phase difference obtained by performing the same calculation as in the first embodiment. In the first embodiment, the number of repetitions is calculated from the quotient obtained by dividing this phase difference by Δp1 shown in Expression 12. In Embodiment 3, Equation 12

Substituting

The number of repetitions θc1 of the first absolute angle sensor 6 can be calculated by slowing down the phase difference by Δp3 obtained in the above. An example of calculating the number of repetitions θc1 is shown in FIG. Therefore, as in the first embodiment, the rotation angle θ including the multiple rotations of the first steering shaft 1 is

Can be calculated. FIG. 24F shows the rotation angle of the first steering shaft thus calculated.

で得られるΔｐ３で、位相差を徐すことで、第２の絶対角センサ７の繰り返し回数δｃ１を算出することができる。この繰り返し回数δｃ１の算出例を図２４（ｅ）に示す。よって、第２のステアリングシャフト２の多回転分を含む回転角度δは、

にて算出できる。このようにして算出した第２のステアリングシャフト４の回転角を図２４（ｇ）に示す。 Next, the number of repetitions of the second absolute angle sensor 7 is calculated by substituting Equation 40 into Equation 17;

The number of repetitions δc1 of the second absolute angle sensor 7 can be calculated by slowing the phase difference by Δp3 obtained in step (3). An example of calculating the number of repetitions δc1 is shown in FIG. Therefore, the rotation angle δ including the multiple rotations of the second steering shaft 2 is

Can be calculated. The rotation angle of the second steering shaft 4 calculated in this way is shown in FIG.

となる。この補正された第２の絶対角センサ７の出力δ２は、第１のステアリングシャフト２を固定して、副回転角を０°にした時の値となるので、実施の形態１と同様に、第１の絶対角センサ６の出力θ１と、第２の絶対角センサ７の補正出力δ２の位相差ｐ１を算出し、（ステップ１００５）、位相差ｐ１を式４０に示したΔｐ３で除した商を基に繰り返し回数θｃ１を算出する。（ステップ１００６’）
さらに、ステップ１００７’では、式４１に基づいて第１のステアリングシャフト２の多回転分を含む回転角θｓ１を算出する。
以上を所定時間毎に繰り返すことにより、第１のステアリングシャフト２の多回転分を含む回転角θ（＝θｓ１）を連続的に検出できる。 Next, calculation of the rotation angle of the first steering shaft 2 when the sub rotation angle is superimposed in the transmission ratio variable mechanism 1 will be described.
The basic processing of the first absolute angle calculation means 10 shown in FIG. 22 is as shown in the first embodiment. The operation will be described with reference to the flowchart of FIG.
Steps 1001 to 1003 read the outputs of the first absolute angle sensor 6, the second absolute angle sensor, and the sub-rotation absolute angle detection means, and are the same as those in the first embodiment. Step 1004 ′ corrects the second auxiliary steering angle sensor δ1 using the output φ1 of the auxiliary rotation absolute angle detection means 9. At this time, since the speed increasing ratio to the second absolute angle sensor 7 with respect to the rotation angle of the second steering shaft 4 is G3, the corrected output of the second absolute angle sensor 7 is the same as that in the first embodiment. Similar to Equation 21 described,

It becomes. Since the corrected output δ2 of the second absolute angle sensor 7 is a value when the first steering shaft 2 is fixed and the sub rotation angle is 0 °, as in the first embodiment, The phase difference p1 between the output θ1 of the first absolute angle sensor 6 and the correction output δ2 of the second absolute angle sensor 7 is calculated (step 1005), and the quotient obtained by dividing the phase difference p1 by Δp3 shown in Equation 40. Based on the above, the number of repetitions θc1 is calculated. (Step 1006 ')
Further, in Step 1007 ′, a rotation angle θs1 including the multiple rotations of the first steering shaft 2 is calculated based on the equation 41.
By repeating the above every predetermined time, the rotation angle θ (= θs1) including the multiple rotations of the first steering shaft 2 can be continuously detected.

が成り立ち、これをθ’について解くと

が得られる。よって、第１の絶対角センサ６の出力は、第１のステアリングシャフト２と第１の絶対角センサ６との増速比Ｇ３を考慮して、

に補正される。（ステップ１１０４’）この補正された第１の絶対角センサ６の出力θ２は、第２のステアリングシャフト２を固定して、副回転角を０°にした時の値となるので、実施の形態１と同様に、第１の絶対角センサ６の補正出力θ２と、第２の絶対角センサ７の出力δ１の位相差ｐ２を算出し、（ステップ１１０５）、位相差ｐ２を式４２に示したΔｐ４で除した商を基に繰り返し回数δｃ１を算出する。（ステップ１１０６’）
さらに、ステップ１００７’では、式４３に基づいて第２のステアリングシャフト４の多回転分を含む回転角δを算出する。
以上を所定時間毎に繰り返すことにより、第２のステアリングシャフト４の多回転分を含む回転角δ（＝δｓ１）を連続的に検出できる。 Next, calculation of the rotation angle of the second steering shaft 4 when the sub rotation angle is superimposed in the transmission ratio variable mechanism 1 will be described. The basic processing of the first absolute angle calculating unit 11 shown in FIG. 22 is as shown in the first embodiment.
The operation will be described with reference to the flowchart of FIG.
Steps 1101 to 1103 read the outputs of the first absolute angle sensor 6, the second absolute angle sensor, and the sub-rotation absolute angle detection means, and are the same as in the first embodiment. Step 1004 ′ corrects the first auxiliary steering angle sensor θ1 using the output φ1 of the auxiliary rotation absolute angle detection means 9. As in the first embodiment, the correction is performed by calculating the output of the first absolute angle sensor 6 when the sub rotation angle φ is set to 0 ° with the second steering shaft 4 fixed. The That is, if the rotation angle of the first steering shaft 2 when the sub rotation angle φ is 0 ° is θ ′,

And solving for θ ′

Is obtained. Therefore, the output of the first absolute angle sensor 6 takes into account the speed increase ratio G3 between the first steering shaft 2 and the first absolute angle sensor 6,

It is corrected to. (Step 1104 ′) The corrected output θ2 of the first absolute angle sensor 6 is a value obtained when the second steering shaft 2 is fixed and the auxiliary rotation angle is set to 0 °. 1, the phase difference p2 between the correction output θ2 of the first absolute angle sensor 6 and the output δ1 of the second absolute angle sensor 7 is calculated (step 1105), and the phase difference p2 is expressed by Equation 42. The number of repetitions δc1 is calculated based on the quotient divided by Δp4. (Step 1106 ′)
Further, in step 1007 ′, the rotation angle δ including the multiple rotations of the second steering shaft 4 is calculated based on the equation 43.
By repeating the above every predetermined time, the rotation angle δ (= δs1) including the multiple rotations of the second steering shaft 4 can be continuously detected.

  As described in the second embodiment, when the control is started, the number of repetitions of each of the first absolute angle sensor 6 and the second absolute angle sensor 7 is set by the above method, and the first absolute angle sensor is set. The rotation angles θ and δ of the first steering shaft 2 and the second steering shaft 3 are detected by counting the number of repetitions in the time series processing of the outputs of the angle sensor 6 and the second absolute angle sensor 7. Is also possible.

  According to the third embodiment, even when the steering wheel is steered at the time of non-control, the absolute angle including the multiple rotations of the first steering shaft and the second steering shaft is set to the same configuration from when the sensor system is activated. The first absolute angle sensor, the second absolute angle sensor, and the sub-rotation absolute angle detection means can be used for detection.

Embodiment 4 FIG.
FIG. 27 is a diagram for explaining a problem when the three sensors of the sensor system for a transmission ratio variable mechanism according to the fourth embodiment of the present invention are not adjusted.
In FIG. 27, the horizontal axis represents the first steering shaft rotation angle (°). 27 (a) to 27 (c), FIG. 27 (f), and FIG. 27 (g) are output values (°), and FIG. 27 (d) and FIG. It is.
27A shows the first absolute angle sensor output, FIG. 27B shows the second absolute angle sensor output, and FIG. 27C shows the first absolute angle sensor output and the second absolute angle. FIG. 27D shows a first iteration count calculation value, FIG. 27E shows a second iteration count calculation value, FIG. 27F shows a first steering shaft rotation angle calculation value, FIG. FIG. 27G shows a second steering shaft rotation angle calculation value.

FIG. 28 is a diagram for explaining the cause of the problem when the three sensors of the transmission ratio variable mechanism sensor system according to the fourth embodiment of the present invention are not adjusted.
28A and 28B, the horizontal axis represents the first steering shaft rotation angle (°), and FIGS. 28C and 28D represent the second steering shaft rotation angle (°). °).
28A shows the first absolute angle sensor output (°), FIG. 28B shows the first calculated number of iterations (times), and FIG. 28C shows the second absolute angle sensor output (°). FIG. 28D shows the second iteration count calculation value (times).

FIG. 29 is a flowchart showing an adjustment method when the handle of the sensor system for a variable transmission ratio mechanism according to Embodiment 4 of the present invention is neutral and the steering wheel is neutral.
FIG. 30 is a flowchart showing an operation of correcting three sensor outputs using adjustment values of the transmission ratio variable mechanism sensor system according to the fourth embodiment of the present invention.

FIG. 31 is a diagram for explaining a sensor adjustment method of the transmission ratio variable mechanism sensor system according to Embodiment 43 of the present invention.
In FIG. 31, the horizontal axis represents the rotation angle, and the vertical axis represents the sensor output.

When the sensor system of the present invention is mounted on a vehicle, when the steering wheel 3 is neutral and the steering wheel of the steering mechanism 5 is neutral, the output of the first absolute angle sensor 6 is 0 °, and the second absolute angle sensor 7 Must be 0 ° and the output of the sub-rotation absolute angle detection means 9 must be 0 °.
However, it is difficult to physically mount the three outputs at 0 ° on the vehicle. That is, there is a high possibility that the first absolute angle sensor 6 and the second absolute angle sensor are mounted on the vehicle in a state where the correlation between the first absolute angle sensor 6 and the second absolute angle sensor is broken.
In the fourth embodiment, a method of adjusting the sensor system in signal processing after each output is mounted on the vehicle in an arbitrary output state will be described.

FIG. 27 shows detection characteristics when the sub-rotation angle by the transmission ratio variable mechanism 1 is 0 °, and the output of the first absolute angle sensor 6 and the output of the second absolute angle sensor 7 at the handle neutral point are not zero. ing. FIG. 27 (f) and FIG. 27 (g) include the absolute angle including the multiple rotations of the first steering shaft 2 and the multiple rotations of the second steering shaft 4 based on the fourth embodiment, respectively. This is an absolute angle detection result. As can be seen from the figure, not only the detection value is offset from the true value, but also, for example, as shown in the A and B portions, discontinuous points occur in the detection value.
Here, the reason why the detection value is offset from the true value is that the outputs of the first absolute angle sensor 6 and the second absolute angle detection sensor 7 shown in FIGS. 27A and 27B are neutral points. It is not 0 ° when (0 °).

On the other hand, the cause of the discontinuity will be described with reference to FIG.
FIG. 28 shows the first absolute angle sensor output, the first iteration count calculation value, the second absolute angle sensor output, and the second iteration count calculation value extracted from FIG.
First, discontinuous points in the detected value of the first steering shaft 2 will be described. FIG. 28A shows the output of the first absolute angle sensor 2, and FIG. 28B shows the output of the first absolute angle sensor 2 and the second absolute angle as described in the fourth embodiment. It is a calculated value of the number of repetitions of the first absolute angle sensor 2 calculated from the deviation of the output of the angle sensor 4. Originally, the change point (for example, B) of the first number of repetitions shown in FIG. 28 (b) must coincide with the 0 point (for example, A) of the output of the first absolute angle sensor 2, Since the correlation between the first absolute angle sensor 2 and the second absolute angle sensor 4 is shifted, a different result is obtained as shown in the figure. Therefore, between A and B in the figure, as shown in A of FIG. 27F, the rotation angle of the first steering shaft 2 is detected as a discontinuous output.
The same applies to the second steering shaft 4, and as shown in FIGS. 28 (c) and 28 (d), between C and D in the figure, as shown in B of FIG. 27 (g). In addition, the rotation angle of the second steering shaft 4 is detected as a discontinuous output.

Next, an adjustment method will be described. The adjustment method described below mainly considers adjustment at the time of vehicle manufacture. That is, at the time of manufacturing the vehicle, the steering wheel is attached and fixed to the steering shaft so as to be neutral when the steering wheel is neutral, and adjustment is performed in this state.
FIG. 29A shows a flowchart during adjustment. Step 2901 determines the presence / absence of an adjustment instruction. The adjustment instruction here is, for example, when the apparatus is started for the first time, external input by a switch or the like, reception of an adjustment command via a communication line, and the like. If the adjustment instruction is confirmed in step 2901, the process proceeds to step 2902, where the output θ1o of the first absolute angle sensor 6 is read. In step 2903, the read output θ1o of the first absolute angle sensor 6 is obtained. Recorded as an adjustment value θcal. Here, the adjustment value θcal is described so as to be set based on one output of the first absolute angle sensor 6, but may be an average value of the output of the first absolute angle sensor 6 a predetermined number of times.
In step 2904, the output δ1o of the second absolute angle sensor 7 is read. In step 2905, the read output δ1o of the second absolute angle sensor is recorded as the adjustment value δcal. Here, the adjustment value δcal has been described so as to be set based on one output of the second absolute angle sensor 7, but may be an average value of the output of the second absolute angle sensor 7 a predetermined number of times.

In step 2906, the output of the sub rotation absolute angle detection means 9 is reset to 0 °.
A method for resetting the sub-rotation absolute angle detection means 9 of the fourth embodiment will be described. The case where the sub rotation absolute angle detecting means 9 uses the sub rotation angle sensor 901 that repeatedly outputs an absolute angle within a predetermined angle every predetermined angle will be described.
In step 2906a, the output φso of the sub rotation angle sensor 901 is read. In step 2906b, the read output φso of the sub rotation angle sensor 901 is recorded as the adjustment value φcal. Here, the adjustment value φcal is described as being set based on the output of the single auxiliary rotation angle sensor 901, but may be an average value of the output of the auxiliary rotation angle sensor 901 of a predetermined number of times.
In step 2906c, φc in which the number of repetitions of the sub rotation angle sensor 901 is recorded is cleared to zero. On the other hand, if the sub-rotation absolute angle detecting means 9 is constituted by a so-called encoder that counts two pulses, the count value φe is set to 0 in step 2906d as shown in FIG. clear.

であり、０°ではない。そこで、読み込まれた第１の絶対角センサ６の出力θ１ｏと、記録された第１の絶対角センサ調整値θｃａｌより、

という演算をすると、第１のステアリングシャフト２が０°（中立）の時の演算結果は０°となる。しかし、式４９の演算のみでは、その演算結果範囲が −θｃａｌ〜３６０−θｃａｌとなり、そのままでは実施の形態１で示した図５のステップ１００１や、図７のステップ１１０１の置き換えとならない。そのため、ステップ３００２では、

という演算をすることにより、結果範囲が０〜３６０になるように変換している。 FIG. 30 is a flowchart for adjusting each sensor using the adjustment value set above. FIG. 30A is an output conversion flow of the first absolute angle sensor 6, and FIG. 5 step 1001 shown in the first embodiment, step 1101 in FIG. 7, and FIG. 19 shown in the second embodiment. This is a replacement of step 1301, step 1401 in FIG. 21, and step 1001 in FIG. 25 and step 1101 in FIG.
In step 3001, the output θ1o of the first absolute angle sensor 6 is read. Next, in step 3002, the output is converted using θcal which is the output of the first absolute angle sensor 6 described above when the recorded first steering shaft 2 is 0 ° (neutral). As described above, the first absolute angle sensor 6 must have an output of 0 ° when the first steering shaft 2 is 0 ° (neutral). However, the output at this time is

It is not 0 °. Therefore, from the read output θ1o of the first absolute angle sensor 6 and the recorded first absolute angle sensor adjustment value θcal,

The calculation result when the first steering shaft 2 is 0 ° (neutral) is 0 °. However, with only the calculation of Expression 49, the calculation result range becomes −θcal to 360−θcal, and as it is, the step 1001 of FIG. 5 and the step 1101 of FIG. Therefore, in step 3002,

Is converted so that the result range is 0 to 360.

This is shown in FIG.
In FIG. 31, θ1o is not 0 ° output when the first steering shaft 2 is 0 ° (neutral), but repeatedly outputs 0 to 360 ° for each predetermined angle. Since θcal is the output of the first absolute angle sensor 6 when the first steering shaft 2 is 0 ° (neutral), the point shown in the figure is the value θcal. The result θ1 calculated from the output θ1o of the first absolute angle sensor 6 and the first absolute angle sensor adjustment value θcal according to the equation 50, and 0 ° when the first steering shaft 2 is 0 ° (neutral). The output is converted so that 0 to 360 ° is repeatedly output at every predetermined angle.
The conversion methods of the second absolute angle sensor 7 and the sub rotation angle sensor 901 are also equivalent to the conversion method of the first absolute angle sensor 6, and the flowcharts thereof are FIGS. 30 (b) and 30 (c). The input step of each sensor in the first embodiment, the second embodiment, and the third embodiment is replaced. An outline of the operation is shown in FIG. 31 as with the first absolute angle sensor 6.

The first absolute angle sensor adjustment value, the second absolute angle adjustment value, and the auxiliary rotation angle adjustment value are recorded in an electrically rewritable EEPROM or flash memory. Similarly, the adjusted flag is recorded in an electrically rewritable EEPROM or flash memory.
If the adjusted flag is not set, it is better to inhibit the driving means 8 from driving the sub rotation angle. If the end value of the sub-rotation angle is not recorded because the power is turned off during the sub-rotation angle drive control by the driving means 8, an accurate sub-rotation angle cannot be obtained when the control is resumed.
In preparation for this case, during the drive control of the sub rotation angle by the driving means 8, the adjusted flag is cleared and recorded, and when the sub rotation angle is stored at the end of the control, the adjusted flag is set again. It is better to set and record.

  According to the fourth embodiment, there is no need to adjust the mechanical rotation angles of the three sensors of the first absolute angle sensor, the second absolute angle sensor, and the auxiliary rotation absolute angle detection means and mount them on the vehicle.

Embodiment 5 FIG.
FIG. 32 is a flowchart showing an adjustment method for adjusting the sensor system individually when the steering wheel of the transmission ratio variable mechanism sensor system according to Embodiment 5 of the present invention is neutral and when the steering wheel is neutral.

In the fourth embodiment, the adjustment method when the steering wheel and the steering wheel are simultaneously neutral is shown.
In the fifth embodiment, a method of individually adjusting the neutral position of the steering wheel and the neutral position of the steering wheel will be described.
Next, the operation will be described with reference to the flowchart shown in FIG.
In step 3201, it is determined whether or not a steering wheel neutral adjustment instruction has been issued. That is, when the steering wheel is neutral with the steering wheel in a neutral state, the process proceeds to step 3202. In step 3202, the output θ1o of the first absolute angle sensor 6 is read. In step 3203, the output θ1o of the first absolute angle sensor 6 read in step 3202 is recorded as the first absolute angle sensor adjustment value θcal, and the first absolute angle calculation means in step 3206 uses the first absolute angle calculation means. The absolute angle sensor repetition number θc2 is set to zero.
In step 3204, a handle neutral adjusted flag indicating that the handle neutral point adjustment has been completed is set. In step 3205, it is determined from the handle adjustment completed flag whether or not the adjustment has been made.

In step 3206, the steering wheel angle is calculated based on steps 1308 to 1314 of FIG. 19 which is the flowchart of the third absolute angle calculating means described in the second embodiment. However, step 1308 is replaced with FIG. 30A using the first absolute angle sensor output adjustment value θcal set in step 3203 as in the fourth embodiment.
Therefore, the steering wheel angle calculated in step 3206, that is, the rotation angle θ of the first steering shaft 2 is a value adjusted to be 0 ° at the neutral position of the steering wheel. In step 3207, it is determined whether or not a steering wheel neutral adjustment instruction has been issued. That is, in a state where the steering wheel is neutralized by steering the steering wheel, the steering wheel neutral instruction is given, and the process proceeds to step 3208.
In step 3208, the output δ1o of the second absolute angle sensor 7 is read. In step 3209, the output δ1o of the second absolute angle sensor 7 read in step 3208 is recorded as the second absolute angle sensor adjustment value δcal, and used in the process of the fourth absolute angle calculation means in step 3212. The absolute angle sensor repetition number δc2 of 2 is set to zero.

にて算出する。ステップ３２１５では、式５１にて求めた副回転角φが得られるよう、副回転絶対角検出手段８の調整を行う。 In step 3210, a steering wheel neutral adjusted flag indicating that the steering wheel neutral point adjustment has been completed is set. In step 3211, it is determined from the steering wheel adjusted flag whether or not it has been adjusted. If it has been adjusted, the process proceeds to step 3212. In Step 3212, the steering wheel angle is calculated based on Steps 1408 to 1414 in FIG. 20 of the fourth absolute angle calculation means described in the second embodiment. However, step 1408 is replaced with FIG. 30B using the second absolute angle sensor output adjustment value δcal set in step 3209 as in the fourth embodiment.
Therefore, the steered wheel angle calculated at step 3212, that is, the rotation angle δ of the second steering shaft 4 is a value adjusted to be 0 ° at the neutral of the steered wheel. In step 3213, it is determined whether or not both the steering wheel angle adjusted flag and the steering wheel angle adjusted flag are set. If both are standing, since the adjusted rotation angle θ of the first steering shaft 2 and the adjusted rotation angle δ of the second steering shaft 4 are both calculated, the process proceeds to step 3214. In step 3214, the sub rotation angle φ is

Calculate with In step 3215, the sub-rotation absolute angle detection means 8 is adjusted so that the sub-rotation angle φ obtained by Expression 51 is obtained.

にて求める。さらに、ステップ３２１５ｂでは、副回転角センサ９０１の出力が、駆動手段８の回転１回転当たり、ｎ回の繰り返しであるとして、副回転角センサの多回転分を含む回転角φｓｃを、

にて求める。ステップ３２１５ｃでは、

にて、副回転角センサ９０１の期待される繰り返し回数が演算され、ステップ３２１５ｄでは、

にて、期待される副回転角センサ９０１の出力値が演算される。すなわち、式５４、式５５にて求めたφｓ、φｃを用いて、実施の形態１の図９のステップ９０９、ステップ９１０の処理を行って求めたφ１が、式５２にて求めたと一致する。ステップ３２１５ｄでは、副回転角センサ９０１の出力φｓｏが読み込まれる。φｓｏは、副回転角センサ９０１の組み込まれた状態により決定される出力なので、式５５で求められたφｓとは異なる。
ステップ２８１５ｅでは、

より、を調整値φｃａｌとして記録する。（ステップ３２１５ｇ）一方、副回転絶対角検出手段９が、２つのパルスを位相計数する所謂エンコーダで構成されている場合は、図３２（ｃ）に示したように、ステップ３２０６ｄにて、計数値φｅを式５２に基づいて計算されたφにセットする。 The case where the sub rotation absolute angle detecting means 9 uses the sub rotation angle sensor 901 that repeatedly outputs an absolute angle within a predetermined angle every predetermined angle will be described. In step 3215a, the rotation angle φM of the driving means 8 is set based on the equation 34.

Ask for. Further, in step 3215b, assuming that the output of the sub rotation angle sensor 901 is repeated n times per rotation of the driving means 8, the rotation angle φsc including the multiple rotations of the sub rotation angle sensor is obtained.

Ask for. In step 3215c,

In step 3215d, the expected number of repetitions of the sub rotation angle sensor 901 is calculated.

Thus, the expected output value of the sub rotation angle sensor 901 is calculated. That is, φ1 obtained by performing the processing of Step 909 and Step 910 in FIG. 9 of the first embodiment using φs and φc obtained by Equation 54 and Equation 55 coincides with that obtained by Equation 52. In step 3215d, the output φso of the sub rotation angle sensor 901 is read. Since φso is an output determined by the state in which the auxiliary rotation angle sensor 901 is incorporated, it is different from φs obtained by Expression 55.
In step 2815e,

Is recorded as an adjustment value φcal. (Step 3215g) On the other hand, when the sub-rotation absolute angle detection means 9 is constituted by a so-called encoder that counts two pulses, as shown in FIG. Set φe to φ calculated based on Equation 52.

  Using the adjustment values θcal, δcal, and φcal set in this way, the output value of each sensor is corrected based on FIG. 30 described in the fourth embodiment, and the accurate first steering shaft 2 A rotation angle including multiple rotations and a rotation angle including multiple rotations of the second steering shaft 4 are detected.

The first absolute angle sensor adjustment value, the second absolute angle adjustment value, and the auxiliary rotation angle adjustment value are recorded in an electrically rewritable EEPROM or flash memory. Similarly, the adjusted flag is recorded in an electrically rewritable EEPROM or flash memory.
If the adjusted flag is not set, it is better to inhibit the driving means 8 from driving the sub rotation angle. If the end value of the sub-rotation angle is not recorded because the power is turned off during the sub-rotation angle drive control by the driving means 8, an accurate sub-rotation angle cannot be obtained when the control is resumed.
In preparation for this case, during the drive control of the sub rotation angle by the driving means 8, the adjusted flag is cleared and recorded, and when the sub rotation angle is stored at the end of the control, the adjusted flag is set again. It is better to set and record.

  According to the fifth embodiment, the sensor system can be adjusted even in a situation where the rotation angle of the first steering shaft and the rotation angle of the second steering shaft cannot be adjusted to zero simultaneously.

Embodiment 6 FIG.
FIG. 33 is a schematic diagram showing a method for detecting a failure in the transmission ratio variable mechanism sensor system according to Embodiment 6 of the present invention.
In FIG. 33, the first absolute angle calculation means 10 (first calculation means) is the same as that described in Embodiment 1, and the third absolute angle calculation means 13 (third calculation means) The fifth absolute angle calculation means 15 (fifth calculation means) outputs the output θ1 of the first absolute angle sensor 6 and the output of the second absolute angle sensor 7, respectively. δ1 and the output φ1 of the sub-rotation absolute angle detection means 9 are input.
The first failure detection means 17 receives the output of the first absolute angle calculation means 10 and the output of the third absolute angle calculation means 13. The second failure detection means 18 receives the output of the first absolute angle calculation means 10 and the output of the fifth absolute angle calculation means 15. The third failure detection means 19 receives the output of the third absolute angle calculation means 13 and the output of the fifth absolute angle calculation means 15.
The second absolute angle calculation means 11 (second calculation means) is the same as that described in the first embodiment, and the fourth absolute angle calculation means 14 (fourth calculation means) is the same as in the second embodiment. As described above, the sixth absolute angle calculation means 16 (sixth calculation means) includes an output θ1 of the first absolute angle sensor 6, an output δ1 of the second absolute angle sensor 7, and a sub-rotation, respectively. The output φ1 of the absolute angle detection means 9 is input.
The fourth failure detection means 20 receives the output of the second absolute angle calculation means 11 and the output of the fourth absolute angle calculation means 14. The fifth failure detection means 21 receives the output of the second absolute angle calculation means 11 and the output of the sixth absolute angle calculation means 16. The sixth failure detection means 22 receives the output of the fourth absolute angle calculation means 14 and the output of the sixth absolute angle calculation means 16.

FIG. 34 is a flowchart showing the operation of the fifth absolute angle calculating means of the sensor system for variable transmission ratio mechanism according to the sixth embodiment of the present invention.
FIG. 35 is a flowchart showing the operation of the sixth absolute angle calculating means of the sensor system for variable transmission ratio mechanism according to the sixth embodiment of the present invention.

The sixth embodiment shows a method for detecting a failure in a sensor system, and an outline is shown in FIG.
Next, the operation of the sixth embodiment will be described. First, the first failure detection means 17 will be described.
The output of the first absolute angle calculation means 10 and the means of the third absolute angle calculation means 13 are input to the first failure detection means 17. As described in the first embodiment, the first absolute angle calculation means 10 is configured so that the rotation angle of the first steering shaft 2, the auxiliary rotation angle, and the rotation angle of the second steering shaft are the same as those of the transmission ratio variable mechanism 1. By utilizing the fact that Equation 1 always holds depending on the characteristics, the first absolute angle sensor 6 output, the second absolute angle sensor 7 output, and the sub-rotation absolute angle detection means 9 output are determined in a predetermined procedure. The absolute angle of one steering shaft 2 is calculated.
On the other hand, as described in the second embodiment, the third absolute angle calculation means 14 is similar to the output of the first absolute angle sensor 6 when the sensor system is activated, like the first absolute angle calculation means. The absolute angle of the first steering shaft 2 is calculated according to a predetermined procedure from the output of the second absolute angle sensor 7 and the output of the sub-rotation absolute angle detection means 9, and thereafter, the first absolute angle sensor 6 Is processed in time series to calculate the absolute angle of the first steering shaft 2.
The output of the first absolute angle detection means 10 and the output of the third absolute angle detection means are as long as the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 are normal. Will output the same result.
Here, let us consider a case where any one of the first absolute angle sensor 6, the second absolute angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails and outputs an incorrect detection value.

The first absolute angle calculation means 10 corrects the output of the second absolute angle sensor 7 with the output of the sub-rotation absolute angle detection means (step 1004 in FIG. 5), and the output of the first absolute angle sensor 6 Since the phase difference of the output of the corrected second absolute angle sensor 7 is calculated (step 1005 in FIG. 5), the calculated phase difference is also incorrect.
Therefore, since the calculation of the number of repetitions based on the incorrect phase difference (step 1006 in FIG. 5) is also incorrect, the calculation is performed from the number of incorrect repetitions and the output of the first absolute angle sensor 6 (step 1007 in FIG. 5). The absolute angle of the first steering shaft 2 is also incorrect.

On the other hand, since the third absolute angle calculation means 13 processes the output of the first absolute angle sensor 6 in time series, it outputs a correct value when a sensor other than the first absolute angle sensor 6 fails. In addition, an incorrect value is output when the first absolute angle sensor 6 is faulty, but since the procedure for calculating the absolute angle is different, the output is different from the output of the first absolute angle calculating means 10. .
Therefore, the first failure detection means 17 calculates the deviation between the output of the first absolute angle calculation means 10 and the output of the third absolute angle calculation means 13, and if this deviation is equal to or greater than a predetermined value, the sensor Determine a system failure.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

Next, the second failure detection means 18 will be described.
The output of the first absolute angle calculation means 10 and the means of the fifth absolute angle calculation means 15 are input to the second failure detection means 18. The operation of the first absolute angle calculation means 10 is as described above.

にて、第１の絶対角センサ６の多回転分を含む回転角が求められる。第１のステアリングシャフト１と第１の絶対角センサ６の間には、減速比Ｇ１があるので、第１のステアリングシャフト２の多回転分を含む絶対角θｓ５は、

にて求められる。すなわち、第５の絶対角算出手段は、式５８に示すように位相差ｐ１のみから第１のステアリングシャフト２の多回転分を含む回転角度を算出する点が、第１の絶対角算出手段１０と異なっている。
第１の絶対角検出手段１０の出力と第５の絶対角検出手段の出力は、第１の絶対角センサ６、第２の接待角センサ７、副回転絶対角検出手段９が正常であれば、同等の結果を出力することになる。
ここで、第１の絶対角センサ６、第２の接待角センサ７、副回転絶対角検出手段９のいずれかが故障して不正な検出値を出力した場合について考える。 Next, the operation of the fifth absolute angle calculation means 15 will be described using the flowchart of FIG.
Steps 1501 to 1505 are the same as steps 1001 to 1005 in FIG. 5 showing the flowchart of the first absolute angle calculation means in the first embodiment, and the first difference from the phase difference P1 obtained in step 1505 is the first. The method of calculating the rotation angle of the steering shaft 2 is different. As described in the first embodiment, this phase difference P1 changes by Δp1 shown in Expression 12 every time the first absolute angle sensor 6 makes one rotation.

Thus, the rotation angle including the multiple rotations of the first absolute angle sensor 6 is obtained. Since there is a reduction ratio G1 between the first steering shaft 1 and the first absolute angle sensor 6, the absolute angle θs5 including the multiple rotations of the first steering shaft 2 is

Is required. That is, the fifth absolute angle calculation means 10 calculates the rotation angle including the multiple rotations of the first steering shaft 2 from only the phase difference p1 as shown in the equation 58. The first absolute angle calculation means 10 Is different.
The output of the first absolute angle detection means 10 and the output of the fifth absolute angle detection means are as long as the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 are normal. The equivalent result will be output.
Here, consider a case where any one of the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails and outputs an incorrect detection value.

  Since the first absolute angle calculating means 10 and the fifth absolute angle calculating means 15 are the same until the phase difference p1 is obtained, they have the same value until the phase difference p1 is obtained. Here, the first absolute angle calculation means 10 calculates only the number of repetitions θc1 of the first absolute angle sensor 6 from the quotient obtained by dividing the phase difference p1 by Δp1 shown in Equation 12, as shown in Equation 22. (Step 1006 in FIG. 5), and the absolute angle including the multiple rotations of the first steering shaft 2 is calculated by the calculation shown in Expression 14, so that it is included in the remainder when the phase difference p1 is divided by Δp1. It can be seen that the rotation angle component is not used.

On the other hand, the fifth absolute angle calculation means 15 calculates the absolute angle including the multiple rotations of the first steering shaft 2 from only the phase difference p1 as shown in the equation 58, so the first absolute angle When any one of the angle sensor 6, the second entertainment angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails, the output of the first absolute angle calculation means 1 and the output of the fifth absolute angle calculation means 15 are used. Deviation occurs.
Therefore, the second failure detection means 18 calculates the deviation between the output of the first absolute angle calculation means 10 and the output of the fifth absolute angle calculation means 15, and if this deviation is greater than or equal to a predetermined value, the sensor Determine a system failure.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

Next, the third failure detection means 19 will be described.
The output of the third absolute angle calculating means 13 and the means of the fifth absolute angle calculating means 15 are input to the third failure detecting means 19. The operations of the third absolute angle calculation means 13 and the fifth absolute angle calculation means 15 are both as described above, and the third absolute angle calculation means 13 includes the first absolute angle sensor 6 and the second absolute angle calculation means 13. The initial value of the number of repetitions of the first absolute angle sensor 6 is set from the outputs of the reception angle sensor 7 and the sub-rotation absolute angle detection means 9, and thereafter the output of the first absolute angle sensor 6 is processed in time series. Thus, while the absolute angle including the multiple rotations of the first steering shaft 2 is calculated, the fifth absolute angle calculating means 15 outputs the output of the first absolute angle sensor 6 and the second absolute angle. An absolute angle including multiple rotations of the twenty-first steering shaft 2 is calculated using a phase difference p1 with a correction output obtained by correcting the output of the sensor 7 using the output of the sub-rotation absolute angle detection means 9.
Therefore, in the same manner as the failure detection principle of the first failure detection means 17 and the second failure detection means 18, the third failure detection means 19 outputs the output of the third absolute angle calculation means 13 and the fifth The deviation of the output of the absolute angle calculation means 15 is calculated, and if this deviation is greater than or equal to a predetermined value, it is determined that the sensor system has failed.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

Next, the fourth failure detection means 20 will be described.
The output of the second absolute angle calculation means 11 and the means of the fourth absolute angle calculation means 14 are input to the fourth failure detection means 20. As described in the first embodiment, the second absolute angle calculation unit 11 is configured so that the rotation angle of the first steering shaft 2, the auxiliary rotation angle, and the rotation angle of the second steering shaft are the same as those of the transmission ratio variable mechanism 1. Using the fact that Equation 1 always holds depending on the characteristics, the first absolute angle sensor 6 output, the second absolute angle sensor 7 output, and the sub-rotation absolute angle detection means 9 output in a predetermined procedure. The absolute angle of the second steering shaft 4 is calculated.
On the other hand, as described in the second embodiment, the fourth absolute angle calculation means 14 is similar to the output of the first absolute angle sensor 6 when the sensor system is activated, like the first absolute angle calculation means. The absolute angle of the second steering shaft 4 is calculated according to a predetermined procedure from the output of the second absolute angle sensor 7 and the output of the sub-rotation absolute angle detection means 9. The absolute angle of the second steering shaft 4 is calculated by processing the output in time series.
The output of the second absolute angle detection means 11 and the output of the fourth absolute angle detection means are as long as the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 are normal. Will output the same result.
Here, consider a case where any one of the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails and outputs an incorrect detection value.

The second absolute angle calculation means 11 corrects the output of the first absolute angle sensor 6 with the output of the sub-rotation absolute angle detection means (step 1104 in FIG. 7), and the corrected first absolute angle sensor 6 Is calculated (step 1105 in FIG. 7), and the calculated phase difference is also incorrect.
Therefore, since the calculation of the number of repetitions based on the incorrect phase difference (step 1106 in FIG. 7) is also incorrect, the calculation is performed from the number of incorrect repetitions and the output of the second absolute angle sensor 7 (step 1107 in FIG. 7). The absolute angle of the second steering shaft 4 is also incorrect.

On the other hand, since the fourth absolute angle calculation means 14 processes the output of the second absolute angle sensor 7 in time series, it outputs a correct value when a sensor other than the second absolute angle sensor 7 fails. In addition, an incorrect value is output when the second absolute angle sensor 6 is faulty, but since the procedure for calculating the absolute angle is different, the value is different from the output of the second absolute angle calculating means.
Therefore, the fourth failure detection means calculates the deviation between the output of the second absolute angle calculation means 11 and the output of the fourth absolute angle calculation means 14, and if this deviation is greater than or equal to a predetermined value, the sensor system It is determined that there is a failure.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

Next, the fifth failure detection means 18 will be described.
The fifth failure detection means 21 receives the output of the second absolute angle calculation means 11 and the means of the sixth absolute angle calculation means 16. The operation of the second absolute angle calculation means 11 is as described above.

にて、第２の絶対角センサ７の多回転分を含む回転角が求められる。第２のステアリングシャフト４と第２の絶対角センサ６の間には、減速比Ｇ２があるので、第２のステアリングシャフト４の多回転分を含む絶対角δｓ６は、

にて求められる。すなわち、第６の絶対角算出手段は、式６０に示すように位相差ｐ２のみから第２のステアリングシャフト４の多回転分を含む回転角度を算出する点が、第２の絶対角算出手段１１と異なっている。 The operation of the sixth absolute angle calculation means 16 will be described using the flowchart of FIG.
Steps 1601 to 1605 are the same as Steps 1101 to 1105 in FIG. 7 showing the flowchart of the second absolute angle calculation means 11 in Embodiment 1, and the first difference is calculated from the phase difference P2 obtained in Step 1605. The method of calculating the rotation angle of the two steering shafts 4 is different. As described in the first embodiment, the phase difference P2 changes by Δp2 expressed by Expression 17 every time the second absolute angle sensor 6 makes one rotation.

Thus, the rotation angle including the multiple rotations of the second absolute angle sensor 7 is obtained. Since there is a reduction ratio G2 between the second steering shaft 4 and the second absolute angle sensor 6, the absolute angle δs6 including the multiple rotations of the second steering shaft 4 is

Is required. That is, the sixth absolute angle calculation means 11 calculates the rotation angle including multiple rotations of the second steering shaft 4 from only the phase difference p2 as shown in the equation 60. Is different.

The output of the second absolute angle detection means 11 and the output of the sixth absolute angle detection means are as follows if the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 are normal. The equivalent result will be output.
Here, consider a case where any one of the first absolute angle sensor 6, the second reception angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails and outputs an incorrect detection value.
Since the second absolute angle calculation means 11 and the sixth absolute angle calculation means 16 are the same until the phase difference p2 is obtained, they have the same value until the phase difference p2 is obtained. Here, in the second absolute angle calculation means 11, only the number of repetitions δc1 of the second absolute angle sensor 7 is calculated from the quotient obtained by dividing the phase difference p1 by Δp1 shown in Equation 17 as shown in Equation 28 ( Step 1106 in FIG. 7), and the absolute angle including the multiple rotations of the second steering shaft 4 is calculated by the calculation shown in Equation 19, so the rotation included in the remainder when the phase difference p2 is divided by Δp2. It can be seen that the angle component is not used.

On the other hand, the sixth absolute angle calculation means 16 calculates the absolute angle including the multiple rotations of the second steering shaft 4 from only the phase difference p2 as shown in the equation 60. If any one of the angle sensor 6, the second entertainment angle sensor 7, and the auxiliary rotation absolute angle detection means 9 fails, the output of the second absolute angle calculation means 11 and the output of the sixth absolute angle calculation means 16 are used. Deviation occurs.
Therefore, the fifth failure detection means 21 calculates the deviation between the output of the second absolute angle calculation means 11 and the output of the sixth absolute angle calculation means 16, and if this deviation is greater than or equal to a predetermined value, the sensor system It is determined that there is a failure.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

Next, the sixth failure detection means 22 will be described.
The output of the fourth absolute angle calculation unit 14 and the output of the sixth absolute angle calculation unit 16 are input to the sixth failure detection unit 22. The operations of the fourth absolute angle calculating means 14 and the sixth absolute angle calculating means 16 are both as described above, and the fourth absolute angle calculating means 14 includes the first absolute angle sensor 6 and the second absolute angle sensor 6. The initial value of the number of repetitions of the second absolute angle sensor 7 is set based on the outputs of the reception angle sensor 7 and the sub-rotation absolute angle detection means 9, and thereafter the output of the second absolute angle sensor 7 is processed in time series. Thus, while the absolute angle including the multiple rotations of the second steering shaft 4 is calculated, the sixth absolute angle calculation means 16 uses the output of the first absolute angle sensor 6 as the auxiliary rotation absolute angle detection means. The absolute angle including the multiple rotations of the second steering shaft 4 is calculated using the phase difference p2 between the corrected output corrected using the output 9 and the output of the second absolute angle sensor 7.
Accordingly, in the same manner as the failure detection principle of the fourth failure detection means 20 and the fifth failure detection means 21, the sixth failure detection means 22 outputs the output of the fourth absolute angle calculation means 14 and the sixth The deviation of the output of the absolute angle calculation means 16 is calculated, and if this deviation is greater than or equal to a predetermined value, it is determined that the sensor system has failed.
Further, even if the failure is determined after the deviation continues for a predetermined time by a predetermined value or more, the time when the deviation is a predetermined value or more is integrated, and the failure is determined when the integrated time becomes a predetermined value or more, or Alternatively, a low-pass filter may be applied to the deviation, and a failure may be determined when the output of the filter becomes a predetermined value or more, or when the predetermined value or more continues for a predetermined time.

  Although the first to sixth failure detection means have been described above, at least one or more of these may be provided as the failure detection means of the sensor system.

  According to the sixth embodiment, it is possible to accurately detect a failure of any sensor constituting the sensor system.

In the above description, the characteristic of the transmission ratio variable mechanism 1 has been described on the premise that it is the expression 1. However, the characteristic is not captured by this characteristic but given by the expression 38 as described in the third embodiment. It also applies to those with
In this case, although the formula for calculating the rotation angle of the steering shaft in the fifth absolute angle calculation means 15 and the sixth absolute angle calculation means 16 is changed, it can be obtained by applying the same concept. .
Furthermore, the output of the first absolute angle sensor 6, the output of the sub-rotation absolute angle detection means 9, and the output of the second absolute angle sensor 7 used in the above description are the same as those in the fourth and fifth embodiments. As shown, the output may be adjusted.
In addition, in the state where the adjustment as shown in the fourth and fifth embodiments is not performed, the failure determination condition may be satisfied even if no failure has occurred in each sensor. It is better not to judge the failure.

It is a block diagram which shows the sensor system for transmission ratio variable mechanisms by Embodiment 1 of this invention. It is a figure explaining the process outline | summary of the sensor system for transmission ratio variable mechanisms by Embodiment 1 of this invention. It is a figure explaining the method of calculating the frequency | count of repetition from the deviation of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a figure which shows the example of an output of the 1st absolute angle sensor of the transmission ratio variable mechanism sensor system by Embodiment 1 of this invention, a 2nd absolute angle sensor, and a subrotation absolute angle detection means. It is a flowchart which shows operation | movement of the 1st absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a characteristic view explaining operation | movement of the 1st absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the 2nd absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a characteristic view explaining operation | movement of the 2nd absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a figure explaining the problem in case there exists an error in the 1st absolute angle sensor output of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention, and a 2nd absolute angle sensor output. It is a figure explaining the factor of a problem when there is an error in the 1st absolute angle sensor output of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention, and the 2nd absolute angle sensor output. It is a figure explaining another problem when there is an error in the 1st absolute angle sensor output and the 2nd absolute angle sensor output of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a figure explaining the factor of another problem when there is an error in the 1 absolute angle sensor output and the 2nd absolute angle sensor output of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a block diagram which shows the subrotation absolute angle detection means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the subrotation absolute angle detection means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a figure explaining operation | movement of the subrotation absolute angle detection means of the sensor system for variable transmission ratio mechanisms by Embodiment 1 of this invention. It is a figure explaining operation | movement of the encoder of the sensor system for transmission ratio variable mechanisms by Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the subrotation absolute angle detection means using the encoder of the sensor system for transmission ratio variable mechanisms by Embodiment 1 of this invention. It is a block diagram which shows the sensor system for transmission ratio variable mechanisms by Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the 3rd absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 2 of this invention. It is explanatory drawing which shows the repetition count method of the 3rd absolute angle calculation means of the sensor system for transmission ratio variable mechanisms by Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the 4th absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 2 of this invention. It is a block diagram which shows the sensor system for transmission ratio variable mechanisms by Embodiment 3 of this invention. It is a figure explaining the detection characteristic of the 1st absolute angle sensor and 2nd absolute angle sensor of the sensor system for transmission ratio variable mechanisms by Embodiment 3 of this invention. It is explanatory drawing of the method to detect the absolute angle of the 1st and 2nd steering shaft of the sensor system for transmission ratio variable mechanisms by Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the 1st absolute angle calculation means of the sensor system for transmission ratio variable mechanisms by Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the 2nd absolute angle calculation means of the sensor system for transmission ratio variable mechanisms by Embodiment 3 of this invention. It is a figure explaining the problem when not adjusting three sensors of the sensor system for transmission ratio variable mechanisms by Embodiment 4 of this invention. It is a figure explaining the factor of a problem when the three sensors of the sensor system for variable transmission ratio mechanisms by Embodiment 4 of this invention are not adjusted. It is a flowchart which shows the adjustment method when the steering wheel of the sensor system for variable transmission ratio mechanisms by Embodiment 4 of this invention is neutral, and the steering wheel is neutral. It is a flowchart which shows the operation | movement which correct | amends three sensor outputs using the adjustment value of the sensor system for transmission ratio variable mechanisms by Embodiment 4 of this invention. It is a figure explaining the adjustment method of the sensor of the sensor system for transmission ratio variable mechanisms by Embodiment 4 of this invention. It is a flowchart which shows the adjustment method which adjusts a sensor system separately when the handle | steering wheel of the sensor system for transmission ratio variable mechanisms by Embodiment 5 of this invention is neutral, and a steering wheel is neutral. It is the schematic which shows the method of detecting the failure of the sensor system for transmission ratio variable mechanisms by Embodiment 6 of this invention. It is a flowchart which shows operation | movement of the 5th absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 6 of this invention. It is a flowchart which shows operation | movement of the 6th absolute angle calculation means of the sensor system for variable transmission ratio mechanisms by Embodiment 6 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission ratio variable mechanism 2 1st steering shaft 3 Handle 4 2nd steering shaft 5 Steering wheel 6 1st absolute angle sensor 7 2nd absolute angle sensor 8 Drive means 9 Subrotation absolute angle detection means 10 1st Absolute angle calculating means 11 Second absolute angle calculating means 12 Sub rotation angle limiting means 13 Third absolute angle calculating means 14 Fourth absolute angle calculating means 15 Fifth absolute angle calculating means 16 Sixth absolute angle calculating Means 17 First failure detection means 18 Second failure detection means 19 Third failure detection means 20 Fourth failure detection means 21 Fifth failure detection means 22 Sixth failure detection means 601 First gear 602 First Second gear 603 First absolute angle sensor 604 Absolute angle sensor 701 of the type that directly detects the rotation angle of the steering shaft Third gear 702 Fourth gear 703 Second absolute angle sensor 704 Absolute angle sensor 901 auxiliary rotary angle sensor 902 auxiliary rotary absolute angle calculation unit 903 storage unit of the type which detects the rotation angle of the tangent steering shaft

Claims (17)

By superimposing the sub-rotation angle on the transmission characteristics of the rotational motion between the first steering shaft that rotates integrally with the steering wheel and the second steering shaft that rotates integrally with the steering wheel. A transmission ratio variable mechanism sensor system used for a variable transmission ratio variable mechanism,
For each first predetermined angle of the first steering shaft, a first absolute angle sensor that repeatedly detects an absolute angle within the first predetermined angle range, the sub rotation angle being fixed, A second absolute angle sensor that repeatedly detects an absolute angle within the second predetermined angle range, and an absolute angle including a multi-rotation component of a sub rotation angle, for each second predetermined angle of the second steering shaft. With a sub-rotation absolute angle detection means,
Based on the output of the first absolute angle sensor, the output of the second absolute angle sensor, the output of the auxiliary rotation absolute angle detection means, and the characteristics of the transmission ratio variable mechanism, the number of the first steering shafts can be increased. Either or both of the first steering shaft absolute angle calculating means for calculating the absolute angle including the rotation component and the second steering absolute angle calculating means for calculating the absolute angle including the multiple rotation component of the second steering shaft. A sensor system for a transmission ratio variable mechanism. By superimposing the sub-rotation angle on the transmission characteristics of the rotational motion between the first steering shaft that rotates integrally with the steering wheel and the second steering shaft that rotates integrally with the steering wheel. A transmission ratio variable mechanism sensor system used for a variable transmission ratio variable mechanism,
In the transmission ratio variable mechanism, the transmission ratio between the rotation angle of the first steering shaft and the rotation angle of the second steering shaft in a state where the sub rotation angle is fixed is not 1: 1 or 1: -1. Configured,
A first absolute angle sensor for repeatedly detecting an absolute angle within the first predetermined angle range for each first predetermined angle of the first steering shaft; a first predetermined angle of the second steering shaft; A second absolute angle sensor that repeatedly detects an absolute angle within the second predetermined angle range for each second predetermined angle that is the same value, and a sub rotation that detects an absolute angle including multiple rotation components of the sub rotation angle With absolute angle detection means,
From the output of the first absolute angle sensor, the output of the second absolute angle sensor, the output of the sub-rotation absolute angle sensor, and the characteristics of the transmission ratio variable mechanism, the multiple rotation of the first steering shaft. One or both of a first steering shaft absolute angle calculating unit that calculates an absolute angle including a component and a second steering absolute angle calculating unit that calculates an absolute angle including a multi-rotation component of the second steering shaft are provided. A transmission ratio variable mechanism sensor system comprising:   The first steering shaft absolute angle calculation means corrects the output of the second absolute angle sensor by using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism. First iteration number calculating means for calculating the number of repetitions of the first predetermined angle of the first absolute angle sensor from the difference between the output of the second absolute angle sensor and the output of the first absolute angle sensor. And the absolute angle of the first steering shaft is calculated from the output of the first iteration number calculating means and the output of the first absolute angle sensor. The sensor system for a transmission ratio variable mechanism according to claim 1 or 2.   The first steering shaft absolute angle calculating means includes third repetition count counting means for counting the number of repetitions of the first predetermined angle based on a time series change in the output of the first absolute angle sensor. When the sensor system is activated, the output of the second absolute angle sensor is corrected using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and the corrected second absolute angle is corrected. A first iteration number calculating means for calculating the number of repetitions of the first predetermined angle of the first absolute angle sensor from the difference between the output of the sensor and the output of the first absolute angle sensor; The output of the first iteration count calculation means is the initial iteration count value of the third iteration count counting means, and the output of the first absolute angle sensor and the third iteration count count means Ste Claim 1 or claim 2, wherein the sensor system for the transmission ratio variable mechanism and calculates the absolute angle of the ring shaft. As the first steering shaft absolute angle calculation means, the output of the second absolute angle sensor is corrected by using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism. First iteration number calculating means for calculating the number of repetitions of the first predetermined angle of the first absolute angle sensor from the difference between the output of the second absolute angle sensor and the output of the first absolute angle sensor. First calculation means for calculating the absolute angle of the first steering shaft from the output of the first iteration number calculation means and the output of the first absolute angle sensor;
Third sub-counting means for counting the number of repetitions of the first predetermined angle based on a time-series change of the output of the first absolute angle sensor, and detecting the sub-rotation absolute angle when the sensor system is activated The output of the second absolute angle sensor is corrected using the output of the means and the characteristics of the transmission ratio variable mechanism, and the corrected output of the second absolute angle sensor and the first absolute angle sensor are corrected. The first repetition number calculation means for calculating the number of repetitions of the first predetermined angle of the first absolute angle sensor from the difference in output of the first absolute angle sensor, and the output of the first repetition number calculation means is the third number of repetitions. And a third calculation means for calculating the absolute angle of the first steering shaft from the output of the first absolute angle sensor and the third repetition number counting means. When,
The output of the second absolute angle sensor is corrected using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, the corrected output of the second absolute angle sensor, A fifth calculating means for calculating an absolute angle of the first steering shaft from a difference in output of the first absolute angle sensor;
2. A failure detection means for detecting a failure of the transmission ratio variable mechanism sensor system from an absolute angle deviation calculated by at least two of the three calculation means. The sensor system for a transmission ratio variable mechanism according to claim 2.
  The first repetition number calculation means corrects the output of the second absolute angle sensor by using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and the corrected first value of the second rotation angle sensor. 6. The number of repetitions is calculated from the difference between the output of the second absolute angle sensor, the output of the first absolute angle sensor, and the output of the first absolute angle sensor. The sensor system for a transmission ratio variable mechanism according to any one of the above.   The second steering shaft absolute angle calculation means corrects the output of the first absolute angle sensor by using the output of the auxiliary rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and this correction is performed. Second iteration number calculating means for calculating the number of repetitions of the second predetermined angle of the second absolute angle sensor from the difference between the output of the first absolute angle sensor and the output of the second absolute angle sensor. And the absolute angle of the second steering shaft is calculated from the output of the second iteration number calculating means and the output of the second absolute angle sensor. The sensor system for a transmission ratio variable mechanism according to any one of claims 1 to 6.   The second steering shaft absolute angle calculating means has fourth repetition count counting means for counting the number of repetitions of the second predetermined angle based on a time-series change in the output of the second absolute angle sensor. When the sensor system is activated, the output of the first absolute angle sensor is corrected using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and the corrected first absolute angle is corrected. A second repetition number calculating means for calculating the number of repetitions of the second predetermined angle of the second absolute angle sensor from the difference between the output of the sensor and the output of the second absolute angle sensor; The output of the second iteration count calculation means is the initial iteration count value of the fourth iteration count counting means, and the output of the second absolute angle sensor and the output of the fourth iteration count counting means 2 steals A sensor system for a transmission ratio variable mechanism according to any one of claims 1 to 6, characterized in that to calculate the absolute angle of Gushafuto. As the second steering shaft absolute angle calculation means, the output of the first absolute angle sensor is corrected by using the output of the auxiliary rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and the corrected Second iteration number calculating means for calculating the number of repetitions of the second predetermined angle of the second absolute angle sensor from the difference between the output of the first absolute angle sensor and the output of the second absolute angle sensor. Second calculating means for calculating the absolute angle of the second steering shaft from the output of the second iteration number calculating means and the output of the second absolute angle sensor;
And a fourth repetition number counting means for counting the number of repetitions of the second predetermined angle based on a time series change of the output of the second absolute angle sensor, and detecting the sub rotation absolute angle when the sensor system is activated. The output of the first absolute angle sensor is corrected using the output of the means and the characteristics of the transmission ratio variable mechanism, and the corrected output of the first absolute angle sensor and the second absolute angle sensor are corrected. From the output difference of the second absolute angle sensor, the second repetition number calculating means for calculating the number of repetitions of the second predetermined angle of the second absolute angle sensor. 4 is used to calculate the absolute angle of the second steering shaft from the output of the second absolute angle sensor and the output of the fourth iteration count counting means. Means for calculating
The output of the first absolute angle sensor is corrected using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, the corrected output of the first absolute angle sensor, Sixth calculating means for calculating the absolute angle of the second steering shaft from the difference in output of the second absolute angle sensor;
2. A failure detection means for detecting a failure of the transmission ratio variable mechanism sensor system from deviations of absolute angles calculated by at least two of the three calculation means. A sensor system for a variable transmission ratio mechanism according to claim 6.   The second repetition number calculation means corrects the output of the first absolute angle sensor by using the output of the sub-rotation absolute angle detection means and the characteristics of the transmission ratio variable mechanism, and the corrected first of the second is calculated. 10. The number of repetitions is calculated from the difference between the output of the first absolute angle sensor, the output of the second absolute angle sensor, and the output of the second absolute angle sensor. The sensor system for a transmission ratio variable mechanism according to any one of the above. The sub rotation absolute angle detecting means includes a sub rotation angle sensor that repeatedly detects an absolute angle within the third predetermined angle range for each third predetermined angle of the sub rotation angle, and a sub rotation angle sensor that counts the number of repetitions. A rotation angle repetition number counting means, configured to detect an absolute angle of the sub rotation angle from the sub rotation angle sensor and the sub rotation angle repetition number counting means;
When the control of the transmission ratio variable mechanism control means for controlling the transmission ratio variable mechanism of the vehicle equipped with the transmission ratio variable mechanism is stopped, the sub rotation angle of the transmission ratio variable mechanism is Sub-rotation angle limiting means for preventing rotation beyond a third predetermined angle, and holding means for holding the output of the sub-rotation angle sensor and the output of the sub-rotation angle repetition counting means,
When the control of the transmission ratio variable mechanism control unit is resumed, the holding value of the output of the sub rotation angle sensor, the holding value of the output of the sub rotation angle repeat counting unit, and the output of the sub rotation angle sensor 11. The sensor system for a variable transmission ratio mechanism according to claim 1, wherein the output of the sub-rotation angle repetition counting means is initialized. The sub-rotation absolute angle detection means has two pulse outputs, and is constituted by a rotary encoder that determines forward rotation and reverse rotation from the two pulse outputs and counts the pulse outputs.
When the control of the transmission ratio variable mechanism control means for controlling the transmission ratio variable mechanism of the vehicle equipped with the transmission ratio variable mechanism is stopped, the sub rotation angle of the transmission ratio variable mechanism is predetermined from the sub rotation angle at the stop. Sub-rotation angle limiting means for preventing rotation beyond the angle, and holding means for holding the output of the rotary encoder,
11. The control unit according to claim 1, wherein when the control of the transmission ratio variable mechanism control unit is resumed, the holding value of the sub rotation angle detection unit is set as the initial value of the rotary encoder. The sensor system for the transmission ratio variable mechanism described. The sensor system for a transmission ratio variable mechanism according to any one of claims 1 to 12, the first steering shaft that rotates integrally with the steering handle, and the member that steers the steered wheels rotate integrally. A transmission ratio variable mechanism that changes the transmission characteristic of the rotational operation with the second steering shaft by superimposing the sub-rotation angle;
Based on the output of the first steering shaft absolute angle calculating means, a target auxiliary rotation angle is set, and the transmission ratio variable mechanism is controlled so that the output of the auxiliary rotation absolute angle detecting means coincides with the target auxiliary rotation angle. A target second steering shaft absolute angle is set based on the first control means and the output of the first steering shaft absolute angle calculation means, and the output of the second steering shaft absolute angle calculation means and the above A steering apparatus comprising: a control unit that is one of second control units that controls the transmission ratio variable mechanism so that a target second steering shaft absolute angle matches. The first steering shaft absolute angle calculating means and the second steering shaft absolute angle calculating means each have an offset adjusting means for adjusting an offset,
The offset adjusting means gives an adjustment instruction when the rotation angle of the first steering shaft is 0 ° and the rotation angle of the second steering shaft is 0 °, whereby the first steering shaft absolute angle 13. The three means are adjusted so that outputs of the calculating means, the second steering shaft absolute angle calculating means, and the auxiliary rotation angle detecting means are each 0 °. The transmission ratio variable mechanism sensor system according to any one of the above. The first steering shaft absolute angle calculating means and the second steering shaft absolute angle calculating means each have an offset adjusting means for adjusting an offset,
The offset adjusting means gives an adjustment instruction when the rotation angle of the first steering shaft is the first reference angle, whereby the output of the first steering shaft absolute angle calculating means sets the first reference angle to The second steering shaft absolute angle calculating means outputs the second reference angle by giving an adjustment instruction when the rotation angle of the second steering shaft is the second reference angle. The sub-rotation absolute angle is transmitted from the adjusted output of the first steering shaft absolute angle calculation means and the output of the adjusted second steering shaft absolute angle calculation means. Calculated using the characteristics of the variable ratio mechanism, and adjusted so that the sub-rotation absolute angle detection means outputs the sub-rotation absolute angle. Transmission ratio variable mechanism sensor system according to any one of claims 1 to 12 that.   The control of the transmission ratio variable mechanism by the transmission ratio variable mechanism control means is prohibited when the adjustment is not performed by the offset adjustment means of the transmission ratio variable mechanism sensor system according to claim 14 or 15. A steering apparatus characterized by the above.   16. The fault of the transmission ratio variable mechanism sensor system is not detected when the sensor system for the transmission ratio variable mechanism is not adjusted by the offset adjusting means. The sensor system for the transmission ratio variable mechanism described.

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