JP2003315096A - Absolute rotation angle detection device and steering angle detection device of steering wheel of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absolute rotation angle detection device which can detect absolute rotation angle of a member whose absolute turning angle is to be detected and which is changed in a range exceeding 360°, without using an absolute angle sensor, and to provide a steering angle detection device of a steering wheel of a vehicle which device uses the absolute rotation angle detection device. <P>SOLUTION: The absolute rotation angle detection device is provided with a relative angle sensor 75a for detecting a rotation angle of a column 44a, and a relative angle sensor 75b for detecting a rotation angle of an output shaft 44ba of an electric motor 44b which rotates by rotation ratio exceeding 1 to rotation of the column 44a. The detection device is set such that a case does not exist that the combination of a value of a rotation angle θsa corresponding to each value of an absolute rotation angle θs, and a rotation angle θsb becomes identical when the absolute rotation angle θs of the column 44a changes in a range of absolute rotation angle. On the basis of combination of the rotation angle θsa and the rotation angle θsb, the absolute rotation angle θs of the column 44a is detected without using an absolute angle sensor. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the absolute rotation angle of an absolute rotation angle detection body whose absolute rotation angle, which is a cumulative rotation angle from a reference angle, changes within an absolute rotation angle range exceeding 360 °. The present invention relates to an absolute rotation angle detection device and a steered wheel steering angle detection device for a vehicle using the absolute rotation angle detection device.

[0002]

2. Description of the Related Art In order to control the turning angle of a steering wheel of a vehicle, it is necessary to detect the turning angle of the steering wheel. For this reason, various types of steering angle detection devices for steered wheels of vehicles have been conventionally developed. For example, the steered wheel steering angle detection device disclosed in Japanese Patent Application Laid-Open No. 4-135979 is a reference for a vehicle to go straight. It rotates from the reference angle (neutral position) according to the turning angle of the steered wheels of the vehicle from the steering angle, and the absolute rotation angle, which is the cumulative rotation angle from the reference angle, exceeds 360 ° within the absolute rotation angle range. The same absolute rotation angle of the steering column that changes with
It is possible to detect the turning angle of the steered wheels of the vehicle based on the detected absolute rotation angle.

In the following, an "absolute angle sensor" can directly detect an absolute rotation angle (cumulative rotation angle from a reference angle) that changes within a range exceeding 360 ° (absolute rotation angle within the same range). There is a one-to-one correspondence with the detected value)
It means a rotation angle sensor, and "relative angle sensor" means 3
A rotation angle sensor that cannot directly detect an absolute rotation angle (cumulative rotation angle from the reference angle) that changes within the range of more than 60 ° (the absolute rotation angle and the detected value do not correspond one-to-one within the same range). I will say.

The steering angle detecting device will be described more specifically. The relative angle sensor is constructed by using a so-called rotary encoder, and the neutral position of the steering column and the relative position of the steering column from the neutral position. The rotation angle can be detected.
Further, the absolute angle sensor is configured by using a so-called potentiometer (variable resistor), and can directly detect the absolute rotation angle which is a cumulative rotation angle from the neutral position of the steering column. .

In this device, while the neutral position of the steering column cannot be confirmed by the relative angle sensor, the absolute angle sensor directly detects the absolute rotation angle of the steering column, and the neutral position is determined by the predetermined method. After the confirmation, the absolute rotation angle of the steering column is detected based on the relative rotation angle of the steering column from the neutral position detected by the relative angle sensor.

By the way, in the absolute angle sensor constructed by using the potentiometer, the resistance value itself of the resistor used for detecting the rotation angle changes with time, and the wear of the tentacle (brush) constantly contacting the resistor. Therefore, there is a problem that the detection accuracy of the rotation angle is generally lower than that of the relative angle sensor configured using the rotary encoder.

Therefore, according to the above apparatus, at least after the neutral position of the steering column can be confirmed by the relative angle sensor, the absolute angle of rotation of the steering column is detected by the relative angle sensor which has a higher detection accuracy of the rotation angle than the absolute angle sensor. Since it can be detected, the turning angle of the steered wheels of the vehicle can be accurately detected.

[0008]

Generally, an absolute angle sensor, which is often constructed by using a potentiometer, has a lower detection accuracy of a rotation angle than a relative angle sensor as described above. In addition, there is a problem that it is more expensive than the relative angle sensor. Therefore, in this type of device, it is desirable that the absolute angle sensor is not used.

However, in the above-mentioned conventional device, while the neutral position of the steering column cannot be confirmed by the relative angle sensor, the relative angle sensor alone cannot detect the absolute rotation angle of the steering column. Is essential for the configuration.

The present invention has been made to solve the above-mentioned problems, and detects the absolute rotation angle of an absolute rotation angle detection target that changes within a range exceeding 360 ° without using an absolute angle sensor. It is an object of the present invention to provide a possible absolute rotation angle detection device and a steered wheel steering angle detection device for a vehicle using the absolute rotation angle detection device.

[0011]

SUMMARY OF THE INVENTION The first feature of the present invention made in order to solve the above problem is that the absolute rotation angle, which is the cumulative rotation angle from the reference angle, changes within a predetermined absolute rotation angle range exceeding 360 °. An absolute rotation angle detection device for detecting the absolute rotation angle of the absolute rotation angle detection body, wherein the first rotation body rotates at a first rotation ratio with respect to the rotation of the absolute rotation angle detection body, A second rotating body that rotates at a second rotation ratio with respect to the rotation of the absolute rotation angle detection body, and a first output value that changes within a predetermined output range according to the rotation angle of the first rotating body. Therefore, when the same first output value becomes any one value within the same output range, there are a plurality of the absolute rotation angles of the absolute rotation angle detection body corresponding to the absolute rotation angle range. First rotation angle detecting means for generating a set first output value, The second output value that changes within a predetermined output range according to the rotation angle of the second rotating body, and corresponds to when the second output value becomes any one value within the same output range. A second rotation angle detection means for generating a second output value set such that the absolute rotation angle of the absolute rotation angle detection object exists in the absolute rotation angle range. The angle detecting means and the second rotation angle detecting means correspond to respective values of the absolute rotation angle when the absolute rotation angle of the absolute rotation angle detection body changes within the absolute rotation angle range. The combination of the first output value and the second output value is set so that there is no case where the combination is the same, and the absolute rotation based on the combination of the first output value and the second output value is set. Equipped with detection means to detect the absolute rotation angle of the angle detector There is something.
Note that, here, the “first rotating body” or the “second rotating body” also includes a case of being a rotating body that rotates integrally with the “absolute rotation angle detecting body” (absolute rotation angle detecting body itself). I'm out.

According to this, the first rotation angle detecting means for detecting the rotation angle of the first rotating body rotating at the first rotation ratio with respect to the rotation of the absolute rotation angle detecting body, and the absolute rotation angle detecting means. The second rotation angle detecting means for detecting the rotation angle of the second rotating body that rotates at the second rotation ratio with respect to the rotation of the detecting body both have their output values (first output value and second output value). Is set so that there is a plurality of absolute rotation angles of the same absolute rotation angle detection body corresponding to the above-mentioned absolute rotation angle detection body. Here, the first and second rotation angle detection means having such output characteristics generate output values that periodically fluctuate, for example, every time the first rotation body and the second rotation body rotate 360 °. It can be easily configured by using a relative angle sensor that operates.

Further, the first and second rotation angle detecting means provide the respective values of the absolute rotation angle when the absolute rotation angle of the detected absolute rotation angle changes within the absolute rotation angle range. The corresponding combination of the first output value and the second output value is set so that there is no case where they are the same combination (hereinafter, the first output value and the second output value are set in this way. The state in which it is present is referred to as "the same combination absent state".)

Therefore, when one combination of the first output value and the second output value, which are the output values of the first and second rotation angle detection means, is determined, the detection means determines the absolute rotation angle to be detected corresponding to the combination. One absolute rotation angle of the detection object can be detected within the absolute rotation angle range, and thus the absolute rotation angle of the absolute rotation angle detection object can be detected.

Therefore, according to the absolute rotation angle detecting device of the first aspect of the present invention, the output values of the first and second rotation angle detecting means (first Based on the combination of the output value and the second output value, without using the absolute angle sensor, to detect the absolute rotation angle of the absolute rotation angle detection object that changes within a predetermined absolute rotation angle range exceeding 360 °. You can

In this case, it is preferable that the first rotation ratio and the second rotation ratio have different values. According to this, when the rotation angle of the absolute rotation angle detection body changes, the change amount of the rotation angle of the first rotating body and the change amount of the rotation angle of the second rotating body are different from each other. Even if the first rotation angle detecting means for detecting the rotation angle of the first rotating body and the second rotation angle detecting means for detecting the rotation angle of the second rotating body are configured by the same component, the first rotation ratio and By properly adjusting the second rotation ratio, it is possible to make the first output value and the second output value the same combination absent state. Therefore, the components can be shared, and the manufacturing cost of the device can be reduced.

Further, it is preferable that the first rotation ratio and the second rotation ratio are different values and both are 1 or more. According to this, in addition to the fact that the components can be made common as described above, the absolute rotation subject to rotation is greater than the case where both the first rotation ratio and the second rotation ratio are less than 1. The amount of change in the rotation angle of the first rotating body and the amount of change in the rotation angle of the second rotating body are large with respect to the change in the rotating angle of the angle detection body.

Therefore, the first rotation of the absolute rotation angle of the absolute rotation angle detection body corresponding to the first output value which is the output value of the first rotation angle detection means for detecting the rotation angle of the first rotation body The detection accuracy (resolution) of the angle detection means is improved, and the absolute value of the absolute rotation angle detection object corresponding to the second output value which is the output value of the second rotation angle detection means for detecting the rotation angle of the second rotation body is increased. The detection accuracy (resolution) of the second rotation angle detecting means with respect to the rotation angle is improved. Therefore, the detection accuracy (resolution) of the detection means for the absolute rotation angle of the absolute rotation angle detection object corresponding to the combination of the output values (first output value and second output value) of the first and second rotation angle detection means. As a result, the accuracy of detecting the absolute rotation angle of the detected absolute rotation angle detector is improved.

A second feature of the present invention is that the absolute rotation angle of the detected absolute rotation angle detecting member changes within a predetermined absolute rotation angle range in which the absolute rotation angle, which is a cumulative rotation angle from the reference angle, exceeds 360 °. An absolute rotation angle detection device for detecting
A rotation angle detection unit that generates an output value that changes according to the rotation of the absolute rotation angle detection body or the rotation of the rotation body that rotates at a predetermined rotation ratio with respect to the rotation of the absolute rotation angle detection body. , At least based on the output value of the rotation angle detection means in a state in which the absolute rotation angle detection body is at the end of the rotatable range of the absolute rotation angle when the absolute rotation angle detection body is in the same state While setting a reference value, based on the reference value and the change amount of the rotation angle of the absolute rotation angle detection body from the same state, which is calculated based on the output value of the rotation angle detection means, The detection means for detecting the absolute rotation angle of the absolute rotation angle detection body is provided.

According to this, the rotation angle detecting means responds to the rotation of the absolute rotation angle detection body or the rotation of the rotation body rotating at a predetermined rotation ratio with respect to the rotation of the absolute rotation angle detection body. It is configured to generate a varying output value. Here, the rotation angle detecting means having such an output characteristic is
For example, the absolute rotation angle detection body or the rotation body is 360 °.
This can be easily configured by using a relative angle sensor that generates an output value that periodically changes with each rotation.

Further, the detection means is in the same absolute rotation angle detection body based on at least the output value of the rotation angle detection means when the absolute rotation angle detection body is at the end of the rotatable range. At the same time, the absolute rotation angle reference value is set, and the absolute rotation angle detection from the same state is calculated based on the output value of the rotation angle detection means that can be configured by the relative angle sensor as described above. The change amount of the rotation angle of the body is detected, and the absolute rotation angle of the same absolute rotation angle detection body is detected based on the same reference value and the same change amount from the same reference value. Therefore, the absolute rotation angle detecting device according to the second aspect of the present invention described above does not require an absolute angle sensor, and is 360 degrees.
It is possible to detect the absolute rotation angle of the absolute rotation angle detection object that changes within a predetermined absolute rotation angle range exceeding 0 °.

A third aspect of the present invention is a steering wheel turning angle detection device for a vehicle, which detects a turning angle of a steered wheel of the vehicle from a reference steering angle at which the vehicle travels straight. Of the absolute rotation angle which is a cumulative rotation angle from the reference angle and which changes in accordance with the turning angle of the steered wheels of the vehicle, and which changes within a predetermined absolute rotation angle range exceeding 360 °. The absolute rotation angle of the rotation angle detector is detected using the absolute rotation angle detection device according to the first feature of the present invention or the absolute rotation angle detection device according to the second feature of the present invention, and the detected absolute rotation angle is detected. The steering angle of the steered wheels of the vehicle is detected based on the absolute rotation angle.

According to this, the absolute rotation angle of the detected absolute rotation angle can be detected without using the absolute angle sensor. As a result, the detected absolute rotation angle can be detected without using the absolute angle sensor. The steering angle of the steered wheels of the vehicle can be detected based on the angle.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First Embodiment) First, referring to FIG. 1, a steering wheel operation including a steering angle detection device for a steering wheel of a vehicle including an absolute rotation angle detection device according to a first embodiment of the present invention. A schematic configuration of a vehicle equipped with the device 10 will be described.
This vehicle has two front wheels (left front wheel Tfl and right front wheel Tfr) which are steered wheels steered by the steering wheel operation device 10 and two rear wheels (left rear wheel Trl and right rear wheel Trr) which are non-steered wheels. ) Is a four-wheel vehicle.

This steered wheel operating device 10 includes steered wheels Tfl,
An operation system input unit 20 for steering Tfr, an operation system actuator 30 for applying an appropriate steering reaction force to the operation system input unit 20, and steered wheels Tfl, Tfr to appropriate steering angles. A front wheel steering mechanism section 40 for steering, a brake hydraulic pressure supply section 50 for generating an appropriate braking force on each wheel, and a throttle valve opening degree of an internal combustion engine (not shown) mounted on the vehicle. For controlling the throttle valve opening control device 60, the operation system actuator 30, the front wheel steering mechanism unit 40, the brake fluid pressure supply unit 50, the throttle valve opening control device 60, etc. 70
The steering wheel operation device 10 is configured such that the operation system input unit 20 and the steered wheels Tfl and Tfr are not mechanically connected.

The operation system input section 20 includes a column 21 fixedly mounted on the vehicle body so as to be rotatable in a vertical plane including the longitudinal direction of the vehicle body in front of the driver's seat DS, and a support point 22 on the column 21. It is composed of the column 21 and a control stick 23 which is rotatably supported integrally with the column 21 as a center. When the steering angle of the steered wheels Tfl and Tfr is at a reference steering angle "0 °" at which the vehicle travels straight (hereinafter, referred to as "vehicle straight traveling state"), the control stick 23 has a vehicle body at the support point 22. The left operation portion 23L having a semi-circular shape is arranged on the left side in the left-right direction, and
The right operation portion 23R having a semi-circular shape is arranged on the right side of the vehicle body in the left-right direction (the position shown in FIG. 1.
It is called the "neutral position". ). This left and right operation unit 23L,
By rotating 23R by a driver sitting in the driver's seat DS, the turning angles of the steered wheels Tfl, Tfr can be changed according to the rotating operation.

The operation system actuator 30 decelerates the rotation of the electric motor 32 and the output shaft (not shown) of the electric motor 32, as shown in FIG. And a speed reducer 34 arranged so as to be able to be transmitted to the column 21. The speed reducer 34 is composed of, for example, a planetary gear mechanism. Since the structure and operation of the planetary gear mechanism are well known, detailed description thereof will be omitted here. In addition, in each configuration shown in FIG.
The same components as those shown in FIG. 1 are assigned the same reference numerals as those in FIG. 1 and their description is omitted.

The electric motor 32 applies an appropriate steering reaction force (force in the direction in which the control stick 23 is restored to the neutral position) to the operation system input section 20 in response to the signal Sstr supplied from the electric control device 70. Can be granted.

The front wheel steering mechanism section 40 includes the left and right front wheels Tfl, T.
Links 41L and 41R that are respectively connected to fr and move with the turning of the left and right front wheels Tfl and Tfr, and a joint 42.
The tie rod 43 is connected to the links 41L and 41R via the L and 42R and is movable in the left-right direction of the vehicle body, and a steering actuator 44 for controlling the tie rod 43 to an appropriate position.

As shown in FIG. 3, which is a schematic configuration diagram, the steering actuator 44 includes a rack R integrally formed with the tie rod 43 and a pinion P meshing with the rack R.
A column (absolute rotation angle detection body and first rotating body) 44a which is fixed to one end and extends in the longitudinal direction of the vehicle body which rotates integrally with the pinion P;
A gear G1 that is fixed to the other end of the column 44a and rotates integrally with the column 44a, a gear G2 that meshes with the gear G1, and a gear G2 fixed to one end extend in the vehicle longitudinal direction. An electric motor 44b having an existing output shaft (second rotating body) 44ba is provided (the absolute rotation angle detection body and the first rotating body are integrated, so the first rotation ratio is "1"). is there.).

The tie rod 43 is integrally fixed with a pair of left stopper 43L and right stopper 43R having a predetermined interval in the left-right direction of the vehicle body, and the left end position of the movable range of the tie rod 43 in the left-right direction is the right stopper. 43
R corresponds to the position when it abuts the right end portion 80R of the fixing member 80 fixed to the vehicle body, and the right end position of the movable range is the position when the left stopper 43L abuts the left end portion 80L of the fixing member 80. It corresponds to.

When the tie rod 43 is in the neutral position shown in FIG. 3, the turning angles of the steered wheels Tfl and Tfr become the above-mentioned reference steering angle, and the absolute rotation angle of the column 44a becomes the reference angle "0".
Is configured to be “°”. Also, tie rod 4
When 3 moves from the neutral position to the left end position, the turning angles of the steered wheels Tfl and Tfr change from the same reference steering angle to the right maximum steering angle (a positive value), and the column 44a changes from the same reference angle ( Two rotations clockwise (as seen from the driver) (absolute rotation angle, which is the cumulative rotation angle from the same reference angle, is 72
0 ° ”. (Actually, it does not become “720 °”, but is less than “720 °” and becomes a value near “720 °”.) Then, when the tie rod 43 moves from the neutral position to the right end position. The steering angles of the steered wheels Tfl and Tfr change from the same reference steering angle to the left maximum steering angle (negative value), and the column 44a rotates counterclockwise twice (from the driver's perspective) from the same reference angle. The absolute rotation angle is "-72
0 ° ”. ) Is configured to.

Therefore, the range of the absolute rotation angle (absolute rotation angle range) of the column 44a is "-720 °" or more and "720".
The range is less than 4 ° (4 rotations), and the column 44a
The absolute rotation angle of is changed from the reference angle “0 °” in proportion to the turning angle of the steered wheels Tfl and Tfr from the reference steering angle (the same absolute rotation angle and the same turning angle). Corresponds to one-to-one.).

The ratio of the number of teeth of the gear G2 to the number of teeth of the gear G1 is set to "4/5", and when the column 44a makes four revolutions within the absolute rotation angle range, the output shaft 44ba of the electric motor 44b. Is configured to rotate 5 times (the second rotation ratio, which is the rotation ratio of the rotation of the output shaft 44ba with respect to the rotation of the column 44a, is "5/4"). Further, the electric motor 44b is driven by a signal Ss supplied from the electric control device 70 to control the absolute rotation angle of the column 44a.
fl and Tfr are controlled to be turned.

The brake hydraulic pressure supply unit 50 is a brake hydraulic pressure generator 5 for generating an appropriate braking force for each wheel in response to a signal Sb supplied from the electric control unit 70.
1 and brake fluid pressure pipes 52fl, 52fr for supplying the brake fluid pressure generated by the brake fluid pressure generator 51 for each wheel to the wheel cylinders WCfl, WCfr, WCrl and WCrr arranged on each wheel. 52rl and 52
It consists of rr and. Therefore, a braking force corresponding to the brake fluid pressure supplied by the brake fluid pressure generator 51 is applied to each wheel.

Although the specific construction of the brake fluid pressure generator 51 is not shown, the brake fluid pressure generator 51 is, for example, a fluid pressure pump and a brake fluid of a predetermined high pressure which is constantly operated by the operation of the fluid pressure pump. Accumulator that can be accumulated, and the high pressure supplied from the accumulator can be appropriately reduced for each wheel based on the signal Sb, and the reduced hydraulic pressure can be supplied to each brake hydraulic pressure pipe 52fl, 52fr, 52rl and 52rr. And a pressure adjusting device including a plurality of electromagnetic valves.

The throttle valve opening control device 60 controls the opening of a throttle valve (not shown) arranged in the intake pipe of an engine (not shown) in response to a signal Sa supplied from the electric control device 70 to output the engine. Can be controlled.

The electric control unit 70 includes a microcomputer 71 and wheel speed sensors 72fl, 72fr, 72rl and 72rr capable of detecting wheel speeds Vfl, Vfr, Vrl and Vrr of the wheels Tfl, Tfr, Trl and Trr, respectively. Corresponding to the lateral acceleration sensor 73 capable of detecting the lateral acceleration G generated at the center of gravity of the vehicle, the rotation angle sensor 74 capable of detecting the rotation angle θstr of the control stick 23, and the steering angle θss of the steered wheels Tfl and Tfr. A rotation angle sensor 75 for detecting the absolute rotation angle θs of the column 44a, an angle sensor 76 capable of detecting the accelerator opening θa of the accelerator pedal AP, and a pedaling force sensor 77 capable of detecting the pedaling force Fb of the brake pedal BP. , Tie rod axial force (compressive force or tensile force acting in the axial direction of the tie rod 43) F corresponding to the steering reaction force from the left and right front wheels Tfl, Tfr
Axial force sensors 78L and 78 capable of detecting sl and Fsr, respectively
R and.

The rotation angle θstr of the control stick 23 is determined by the control stick 2
3 becomes "0 °" when in the neutral position, a positive value is obtained when the control stick 23 is rotated in the clockwise direction (as viewed from the driver) from the neutral position, and the control stick 23 is moved from the neutral position. It is set to have a negative value when is rotated counterclockwise.

Specifically, the rotation angle sensor 75 can detect the rotation angle θsa of the column 44a, as shown in FIG.
Relative angle sensor 75 constructed using a so-called resolver
a and a relative angle sensor 75b that can detect the rotation angle θsb of the output shaft 44ba of the electric motor 44b and that is configured by using a resolver. The microcomputer 71 uses these two relative angle sensors 75a, The absolute rotation angle θs of the column 44a can be detected based on the output value of 75b (details will be described later). Further, as described above, since the absolute rotation angle θs and the turning angles θss of the steered wheels Tfl and Tfr have a one-to-one correspondence, the microcomputer 71 detects that the absolute rotation angle θs is the same. The rudder angle θss can also be detected.

The relative angle sensor 75a has 36 columns 44a.
Signal that fluctuates periodically every 0 ° rotation (first output value)
Is set to generate the relative angle sensor 75b
Is set so as to generate a signal (second output value) that periodically changes each time the output shaft 44ba rotates 360 ° (details will be described later). In addition, the relative angle sensor 75a
And the relative angle sensor 75b are composed of the same parts,
The first output value and the second output value change within the same output range.

Although the specific structure of the microcomputer 71 is not shown, the microcomputer 71 is a CP.
U, a ROM that stores beforehand routines (programs), tables (lookup tables, maps), constants, etc., which will be described later, executed by the CPU, RAM for the CPU to temporarily store data when necessary, and an AD converter. It is configured to include the interface including.

The interface is the sensors 72 to 7
8, the signals from the sensors 72 to 78 are supplied to the CPU, and the operation system actuator 30, the steering actuator 44, the brake fluid pressure generation device 51, and the throttle valve opening control device according to the instruction of the CPU. 60
In addition, the control signals Sstr, Ss, Sb, and Sa are respectively transmitted.

The signal Sstr is a signal corresponding to the steering reaction force to be applied to the operation system input section 20.
The signal Ss is a signal for feedback-controlling the same turning angle θss, that is, the absolute rotation angle θs of the column 44a so that the turning angle θss of the steered wheels Tfl and Tfr matches the target steering angle θt. The signal Sb is the pedaling force Fb of the brake pedal BP.
It is a signal corresponding to. Further, the signal Sa is a signal corresponding to the accelerator opening degree θa of the accelerator pedal AP.

Next, the operation of the steered wheel operating device 10 including the steering angle detecting device for the steered wheels of the vehicle including the absolute rotation angle detecting device according to the first embodiment of the present invention configured as described above Will be described with reference to a flowchart showing a routine executed by the CPU of the microcomputer 71.

The CPU repeatedly executes the steering control routine shown by the flowchart in FIG. 4 every time a predetermined time elapses. This steering control routine turns the steered wheels Tfl, Tfr to an appropriate turning angle θss according to the rotation angle θstr from the neutral position when the driver rotates the control stick 23 from the neutral position, and It is a routine that executes a process for applying an appropriate steering reaction force Fstr to the control stick 23.

When the predetermined timing comes, the CPU starts the process from step 400 and proceeds to step 405 to calculate the axial force Fs acting on the tie rod 43. The axial force Fs is a larger value of the axial force Fsl from the left front wheel Tfl detected by the axial force sensor 78L and the axial force Fsr from the right front wheel Tfr detected by the axial force sensor 78R. .

Next, the CPU proceeds to step 410 to calculate an estimated vehicle speed V of the vehicle. The estimated vehicle speed V is an average value obtained by summing the values of the wheel speeds Vfl, Vfr, Vrl, and Vrr of each wheel and dividing by four. It should be noted that the estimated vehicle speed V may be a minimum value of the respective values during traveling at a constant vehicle speed and during acceleration, and may be the maximum value of the respective values during deceleration.

The CPU then proceeds to step 415,
Steering wheels Tfl, Tfr with respect to the rotation angle θstr of the control stick 23
The steering angle ratio R, which is the ratio of the turning angle θss of the above, is calculated from the map corresponding to the graph shown in FIG. The steering angle ratio R is set to a maximum value R1 when the estimated vehicle speed V is "0" and decreases as the estimated vehicle speed V increases. That is, for the same rotation angle θstr of the control stick 23, the smaller the estimated vehicle speed V is, the steered wheels Tf
l and Tfr are steered largely, and the steered wheels Tfl and Tfr are steered smaller as the estimated vehicle speed V increases.

Next, the CPU proceeds to step 420 to calculate the steering reaction force Fstr to be applied to the control stick 23. The steering reaction force Fstr is the axial force Fs calculated in step 405,
It is calculated based on the lateral acceleration G at this point and the function fstr (Fs, G, V) of the estimated vehicle speed V calculated in step 410. The function fstr (Fs, G, V) has a larger proportional value of the axial reaction force Fs, a larger value of the lateral acceleration G, and a larger value of the estimated vehicle speed V. The value is set to be large. After that, the CPU proceeds to step 425 to steer wheels Tfl and Tfr.
The target steering angle θt of is calculated. The target rudder angle θt is the control rod 23
The rotation angle θstr is calculated by multiplying the steering angle ratio R calculated in step 415.

The CPU then proceeds to step 430 and
The steering reaction force Fstr calculated in step 420 is used as the control stick 2
Add to 3. More specifically, the CPU controls the electric motor 32 in the operation system actuator 30 shown in FIG.
The steering reaction force Fstr in the direction of returning θstr to “0 °”
The electric motor 32 supplies the signal Sstr for generating the steering force to the control rod 23, which causes the steering reaction force Fstr.
Is given.

Then, the CPU proceeds to step 435,
The steered wheels Tfl and Tfr are steered so that the steered angles θss of the steered wheels Tfl and Tfr become the target steered angle θt calculated in step 425. Specifically, the CPU is the steering actuator 4
4, the column 44a is calculated by a routine described later so that the target steering angle θt and the turning angle θss match.
A signal Ss for feedback-controlling the absolute rotation angle θs is supplied to control the steering angle θss. Then CP
U proceeds to step 495 to end the present routine tentatively. As described above, the steered wheels Tfl and Tfr are steered to the appropriate turning angle θss according to the rotation angle θstr of the control stick 23, and an appropriate steering reaction force Fstr is applied to the control stick 23.

<Principle of Computing Absolute Rotation Angle θs> Next, the computation (detection) of the absolute rotation angle θs of the column 44a will be described. First, the absolute rotation angle θs of the column 44a (-720 °
≦ θs <720 °) corresponding to each value, the first output value of the relative angle sensor 75a (a signal indicating the rotation angle θsa of the column 44a) and the second output value of the relative angle sensor 75b (rotation of the output shaft 44ba). The principle by which the CPU calculates (detects) the absolute rotation angle θs of the column 44a will be described with reference to FIG. 6, which is a graph showing the transition of the signal indicating the angle θsb).

The value of the rotation angle θsa of the column 44a indicated by the first output value of the relative angle sensor 75a is shown by the solid line in FIG. 6, and the value of the absolute rotation angle θs of the column 44a is "-7".
20 ° ”(when the steered wheels Tfl and Tfr are steered at the left maximum steering angle), it becomes“ 0 ° ”, and from this state, the column 44a rotates clockwise (when viewed from the driver) by 3 °.
Every time it rotates by 60 °, “0 °” to “36” are periodically repeated four times.
Up to 0 °, it is set to increase in proportion to the increase of the absolute rotation angle θs (the value of the rotation angle θsa is “3
Since it becomes “0 °” when it becomes “60 °”, it does not actually become “360 °”. ).

Therefore, the value of the rotation angle θsa is determined by the column 44a.
When the value of the absolute rotation angle θs is between “0 °” and “360 °”, it becomes the same value as the same absolute rotation angle θs, and the value of the same absolute rotation angle θs is “360 °”-“720”. If it is between "°", it becomes a value obtained by subtracting "360 °" from the value of the same absolute rotation angle θs, and the value of the same absolute rotation angle θs is "-360 °"
When it is between "0 °" and "0 °", it becomes a value obtained by adding "360 °" to the value of the same absolute rotation angle θs, and the value of the same absolute rotation angle θs is from "-720 °" to "-360 °". When it is in between, the absolute rotation angle θs becomes a value obtained by adding “720 °”.

As described above, regardless of the value of the rotation angle θsa (first output value) between "0 °" and "360 °", the absolute rotation angle θs of the column 44a corresponding to that value. Is
Within absolute rotation angle range (-720 ° ≤ θs <720 °)
There are four of them, and the value of the absolute rotation angle θs is “720” from the value of the rotation angle θsa at that time.
The value obtained by subtracting “°”, the value obtained by subtracting “360 °” from the value of the same rotation angle θsa, the same value as the value of the same rotation angle θsa, and the value obtained by adding “360 °” to the value of the same rotation angle θsa. The value is one of the values (hereinafter, these four cases are referred to as “classification 1”, “classification 2”, “classification 3”, and “classification 4”, respectively). .

The value of the rotation angle θsb of the output shaft 44ba indicated by the second output value of the relative angle sensor 75b is shown by the alternate long and short dash line in FIG. 6, and the value of the absolute rotation angle θs of the column 44a is "-720 °. When the output shaft 44ba rotates 360 degrees counterclockwise (as viewed from the driver) from this state, the output shaft 44ba is periodically cycled five times to "0 degrees".
Up to "360 °" is set to increase in proportion to the increase of the absolute rotation angle θs (the value of the rotation angle θsb becomes "0 °" when it becomes "360 °". Actually, it will never be "360 °".)

As described above, regardless of the value of the rotation angle θsb (second output value) between “0 °” and “360 °”, the absolute rotation angle θs of the column 44a corresponding to that value. Is
Within absolute rotation angle range (-720 ° ≤ θs <720 °)
There are 5 of them. Further, when the absolute rotation angle θs of the column 44a changes within the absolute rotation angle range, the value (first output value) of the rotation angle θsa corresponding to each value of the absolute rotation angle θs and the rotation angle The combination with the value of θsb (second output value) does not exist in the same combination (the same combination does not exist).

Therefore, when the rotation angle θsa (first output value) has a certain value, there are four absolute rotation angles θs of the corresponding column 44a. There are four angles θsb (second output value). Therefore, for each value of the rotation angle θsa, by predefining in the map which of the above-described categories 1 to 4 the four cases existing as a combination correspond to, the rotation angle θsa From the combination of the rotation angle θsb and the rotation angle θsb, one of the same classifications 1 to 4 is selected, and the value of the same absolute rotation angle θs is calculated (detected) from the value of the same rotation angle θsa and the selected classification. To be done.

For example, the case where the value of the rotation angle θsa is “180 °” will be described. In this case, as shown in FIG. 6, the rotation angle θsb existing as the combination target exists.
There are four types, “225 °”, “315 °”, “45 °” and “135 °”. Then, in the above map, the combination of the rotation angle θsa and the rotation angle θsb is “1.
"80 °" and "225 °" correspond to classification 1, "180 °" and "315 °" correspond to classification 2, and "180 °" and "45 °" If it is, it corresponds to classification 3, "180 °" and "135 °"
If it is, it is specified in advance that it corresponds to the classification 4, so the corresponding classification is selected by the same map. For example, if category 2 is selected, column 44
The absolute rotation angle θs of a is “180” which is the value of the rotation angle θsa.
"-180 °" which is the value obtained by subtracting "360 °" from "°"
Is calculated (detected) as The above is the CPU in column 4
This is the principle of calculating (detecting) the absolute rotation angle θs of 4a.

<Actual Operation> Next, the steering wheel operating device 1 described above.
Regarding the actual operation of the absolute rotation angle detection device (steering wheel steered angle detection device) according to the first embodiment, which is installed in No. 0, refer to the flowchart showing the routine executed by the CPU of the microcomputer 71. While explaining.

The CPU repeatedly executes the absolute rotation angle θs calculation routine shown by the flowchart in FIG. 7 every time a predetermined time elapses. Therefore, at a predetermined timing, the CPU starts the process from step 700, proceeds to step 705, and based on the classification selection map shown in FIG. 8 stored in the ROM, the first output value of the relative angle sensor 75a. Column 44a at the moment indicated by
From the value of the rotation angle θsa of, the integer angle θ closest to the value of the rotation angle θsa is selected.

In this processing, the angle value corresponding to the rotation angle θsa stored in the map is "0 °" to "360 °".
Since there is only an integer angle θ that is an integer value up to
If the value of rotation angle θsa is a real value that is not an integer value, it is necessary to use the same integer angle θ that is the closest integer value to the value of rotation angle θsa, instead of the value of rotation angle θsa. Is executed.

As described above, the value of the rotation angle θsa is
Although it does not become “360 °”, the value of the integer angle θ closest to the value of the rotation angle θsa may be “360 °”. Therefore, the integer angle θ is “360 °” in the map. It also stores the classification in case of.

Next, the CPU proceeds to step 710, and selects the selected integer angle θ and the second value of the relative angle sensor 75b.
Electric motor 44b at the present time indicated by the output value
From the combination with the value of the rotation angle θsb of the output shaft 44ba of
The corresponding classification is selected based on the map shown in FIG. 8. When the corresponding classification is classification 1, the variable CLASS is set to “1”, and when it is classification 2, the variable CLASS is set to “2”. , The variable CLASS is set to “3” in the case of classification 3, and the variable CLASS is set to “4” in the case of classification 4.

The values of the four rotation angles θsb to be combined with respect to the respective values of the rotation angle θsa (integer angle θ) due to the play generated between the gears in the steering actuator 44 are as follows: Since it is possible that there is a slight deviation from the expected value (calculated value), in the map in this example, as shown in FIG. 8, the value of the rotation angle θsb corresponding to each classification is centered on the calculated value. The calculated value has a width of 90 ° (the calculated value is shown in parentheses in FIG. 8). Here, this width is set to 90 ° because of the four rotation angles θsb to be combined.
The difference between the values that are closest to each other must be 90
It is based on the relationship of becoming °.

For example, the rotation angle θsa (integer angle θ) is "1.
In the case of “80 °”, the calculated values of the four rotation angles θsb for selecting the classifications 1 to 4 are “225 °” and “315”, respectively.
Where the rotation angle θsb is 180 ° to 270 ° (225 ° ± 45 °).
Class) is selected when the value of the rotation angle θsb is “270 ° to 360 ° (315 ° ± 45 °)”, and the value of the rotation angle θsb is “0 °”. ~ 90 °
(45 ° ± 45 °) ”, classification 3 is selected, and the value of the rotation angle θsb is“ 90 ° to 180 ° (135 ° ± 45 °).
°) ”, category 4 is selected.

Next, the CPU proceeds to step 715, step 720, and step 725 to determine whether the value of the variable CLASS is "1", "2", "3", or "4". Then, the CPU uses the variable CLA
If the SS value is "1", step 730
Then, the value of the absolute rotation angle θs is set to a value obtained by subtracting “720 °” from the value of the rotation angle θsa, and when the value of the variable CLASS is “2”, the process proceeds to step 735.
The value of the absolute rotation angle θs is calculated from the value of the rotation angle θsa as “360
The value of the variable CLASS is set to "3".
If it is, the process proceeds to step 740, the value of the absolute rotation angle θs is set to the value of the rotation angle θsa, and the variable CLAS is set.
When the value of S is “4”, the process proceeds to step 745, and the value of the absolute rotation angle θs is changed to the value of the rotation angle θsa by “36”.
After setting the value to which "0 °" is added, the routine proceeds to step 795 to end this routine once. From the above, column 44a
The absolute rotation angle θs of is calculated (detected).

As described above, according to the absolute rotation angle detecting device (steering wheel steering angle detecting device of the vehicle) according to the first embodiment, the column 44a indicated by the first output value of the relative angle sensor 75a. Based on the combination of the value of the rotation angle θsa and the value of the rotation angle θsb of the output shaft 44ba of the electric motor 44b indicated by the second output value of the relative angle sensor 75b, 360 ° is obtained without using the absolute angle sensor. Within absolute rotation angle range (-
It is possible to detect the absolute rotation angle θs of the column 44a, which is the absolute rotation angle detection body that changes in the range of 720 ° ≦ θs <720 °), and also to detect the turning angle θss of the steered wheels Tfl and Tfr. did it.

Further, according to the first embodiment, the rotation angle θsa
When determining the combination of the value (first output value) and the value of the rotation angle θsb (second output value), a plurality of (four )
The other value (the value of the rotation angle θsb) is recognized as the calculated value when it is within a predetermined range (a range having a width of 90 ° centering on the calculated value) including the expected calculated value. It
Therefore, the other value (rotation angle θs is caused by backlash generated between the gears in the steering actuator 44).
Even when b) is slightly deviated from the calculated value, the combination of the value of the rotation angle θsa (first output value) and the value of the rotation angle θsb (second output value) can be accurately determined. It was

Further, according to the first embodiment, the column 44
The second rotation ratio, which is the rotation ratio of the rotation of the output shaft 44ba of the electric motor 44b with respect to the rotation of a, is an appropriate value "5/4" different from the first rotation ratio "1". . Therefore, when the rotation angle θsa of the column 44a changes, the change amount of the rotation angle θsa of the column 44a and the output shaft 44b
Since the amount of change in the rotation angle θsb of a differs from each other, the relative angle sensor 75a that detects the rotation angle θsa of the column 44a and the relative angle sensor 75b that detects the rotation angle θsb of the output shaft 44ba.
Even if and are composed of the same component, the rotation angle θsa (first output value) and the rotation angle θsb (second output value) can be in the same combination absent state. Therefore, the components can be made common, and the manufacturing cost of the device can be reduced.

Further, according to the first embodiment, the second
Since the rotation ratio of is “5/4”, which is a value exceeding 1, compared with the case where the second rotation ratio is less than 1,
Output shaft 44ba for changes in rotation angle θsa of column 44a
The amount of change in the rotation angle θsb of is large. Therefore, the rotation angle θ
Regarding the absolute rotation angle θs of the column 44a corresponding to sb,
The detection accuracy (resolution) of the relative angle sensor 75b is improved.
Therefore, the detection accuracy (resolution) of the device (CPU) for the absolute rotation angle θs of the column 44a corresponding to the combination of the rotation angle θsa (first output value) and the rotation angle θsb (second output value) is also improved. As a result, the absolute rotation angle θs of the column 44a
And the steering angle θss of the steered wheels Tfl and Tfr are improved.

In addition, according to the first embodiment, the column 4
When the absolute rotation angle θs of 4a changes within the absolute rotation angle range, the rotation angle θs corresponding to the change of the absolute rotation angle θs
The rate of change of a (first output value) is always constant (changing linearly), and the rate of change of rotation angle θsb (second output value) with respect to the change of absolute rotation angle θs is It is always constant (changing linearly). Therefore, the detection accuracy (resolution) of the device (CPU) for the absolute rotation angle θs of the column 44a corresponding to the combination of the rotation angle θsa (first output value) and the rotation angle θsb (second output value) is the absolute rotation angle range. Becomes constant over time, resulting in column 44
The detection accuracy of the absolute rotation angle θs of a and the detection accuracy of the turning angles θss of the steered wheels Tfl and Tfr are stable.

Although the second rotation ratio is set to "5/4" in the first embodiment, the rotation angle θsa (first output value) and the rotation angle θsb (second output value) are set. ) Can be freely set as long as they are values that can make the same combination absent (for example, 6/5).

(Second Embodiment) Next, a turning angle detecting device for a steering wheel of a vehicle including an absolute rotation angle detecting device according to a second embodiment of the present invention (a steering wheel operating device 1 for a vehicle including these).
0) will be described. The second embodiment differs from the first embodiment only in the configuration of the steering actuator 44, and is the same in other configurations, operations, and the like.

Steering actuator 4 according to the second embodiment
As shown in FIG. 9 showing a schematic configuration thereof, 4 is a gear G3 meshing with the gear G1 and one end of the gear G3 with respect to the steering actuator 44 (see FIG. 3) according to the first embodiment. The electric motor 44c having the output shaft (first rotating body) 44ca extending in the vehicle front-rear direction fixed to the vehicle is added, and the rotation angle detection target of the relative angle sensor 75a is changed from the column 44a to the output shaft 44ca. Only the points differ. In FIG. 9, the same components as those in FIG. 3 are designated by the same reference numerals as those in FIG. Hereinafter, in the second embodiment, the same components as those in the first embodiment will be described with reference to the same symbols as those in the first embodiment, and the differences will be mainly described.

The ratio of the number of teeth of the gear G3 to the number of teeth of the gear G1 is set to "1". When the column (absolute rotation angle detector) 44a makes four revolutions within the absolute rotation angle range, the electric motor The output shaft 44ca of the 44c is configured to rotate four times (the first rotation ratio, which is the rotation ratio of the rotation of the output shaft (first rotating body) 44ca with respect to the rotation of the column 44a, is “1”). Further, similarly to the first embodiment, the ratio of the number of teeth of the gear G2 to the number of teeth of the gear G1 is “4/5”.
The second rotation ratio, which is the rotation ratio of the rotation of the output shaft (second rotating body) 44ba with respect to the rotation of the column 44a, is “5/4”.

Therefore, the absolute rotation angle θs (-of the column 44a is
720 ° ≤ θs <720 °),
The transition of the first output value of the relative angle sensor 75a (a signal indicating the rotation angle θsa of the output shaft 44ca) and the second output value of the relative angle sensor 75b (a signal indicating the rotation angle θsb of the output shaft 44ba) is
This is the same as that in the first embodiment shown in FIG. 6 described above. Therefore, as the map stored in the ROM used when the CPU selects the above classification, the same map as that in the first embodiment shown in FIG. 8 is used, and C
PU is based on the rotation angle θsa (first output value) of the output shaft 44ca, the rotation angle θsb (second output value) of the output shaft 44ba, and the map, and the absolute rotation angle θs and the steering wheel Tf of the column 44a.
The steering angle θss of l and Tfr is detected, and the absolute rotation angle θs and the steering angles θss of the steered wheels Tfl and Tfr are controlled.

The electric motor 44c is the electric motor 4c.
It is not driven while 4b is functioning normally,
The output shaft 44ca of the electric motor 44c is an electric motor 44b.
The column 44a is rotated only passively in association with the rotation of the column 44a whose absolute rotation angle is controlled by the drive of the. On the other hand, when the electric motor 44b fails, the CPU supplies the signal Ss to the electric motor 44c to control the absolute rotation angle θs of the column 44a and the steered angles θss of the steered wheels Tfl and Tfr. Therefore, the electric motor 44c functions as a fail safe when the electric motor 44b fails.

As described above, the absolute rotation angle detecting device (steering wheel steering angle detecting device for a vehicle) according to the second embodiment is substantially the same as the function and effect of the first embodiment. The operating effect was played.

(Modification of Second Embodiment) In the second embodiment, the absolute rotation angle θs of the column 44a (−720 ° ≦
The first output value (θsa) of the relative angle sensor 75a and the second output value (θsb) of the relative angle sensor 75b corresponding to each value of θs <720 °) are as shown in FIG.
The output value (θsa) indicates that the absolute rotation angle θs of the column 44a is “-
720 ° ”to“ 720 ° ”has a sine waveform with one cycle, and the second output value (θsb) has the same absolute rotation angle θs of“ −720 ° ”to“ 360 ° ”. The absolute rotation angle θs is the same as the sine waveform whose half-cycle range is
The range may be set so that the range of 0 ° to “720 °” is a waveform obtained by combining sine waveforms having a half cycle.

In order to set the first output value and the second output value as described above, the first rotating body and the second rotating body are configured to rotate once when the column 44a makes four rotations (the first rotating body and the second rotating body). Both the rotation ratio and the second rotation ratio are "1/4"),
The relative angle sensor 75a that outputs the first output value has a predetermined distance with respect to the rotation axis of the first rotating body having the outer peripheral surface whose profile is shaped so as to generate the above-mentioned sine waveform as the output value. A relative angle sensor 75b configured to use a gap sensor fixed at a distant position and outputting a second output value has an outer peripheral surface whose profile is shaped so as to generate a composite waveform as described above as an output value. It suffices to use a gap sensor fixed at a position separated by a predetermined distance with respect to the rotation axis of the second rotating body having.

In this case, the first rotation ratio and the second rotation ratio have the same value ("1/4"), but the first output value and the second output value are in the same combination nonexistent state. Therefore, the absolute rotation angle θs of the column 44a can be detected based on the combination of the first output value and the second output value.

(Third Embodiment) Next, a turning angle detecting device for a steered wheel of a vehicle including an absolute rotation angle detecting device according to a third embodiment of the present invention (a steered wheel operating device 10 including these). explain. The third embodiment differs from the first embodiment only in the method of calculating the absolute rotation angle θs of the column 44a, and the other configurations, operations, and the like are the same. Hereinafter, in the third embodiment, the same components as those in the first embodiment will be described with the same reference numerals as those in the first embodiment, and the difference will be mainly described.

<Principle of calculating absolute rotation angle θs> First, C
The principle by which the PU calculates (detects) the absolute rotation angle θs of the column 44a will be described. The absolute rotation angle range of the column 44a corresponds to the movable range of the tie rod 43 in the left-right direction, that is, the steerable range of the steered wheels Tfl and Tfr. The maximum and minimum values of the absolute rotation angle range are It is known in advance when the absolute rotation angle detection device (steering wheel steering angle detection device) is designed.

Therefore, the steering angle of the steered wheels Tfl, Tfr is the left or right maximum steering angle, that is, the column 44a is at the end of the rotatable range (hereinafter, if necessary, The state where the left maximum steering angle is the “left end state” and the state where the right maximum steering angle is the “right end state” are referred to as the “right end state.”).
The value (reference value) of the absolute rotation angle θs is the minimum value or the maximum value of the known (design value) absolute rotation angle range, and thus can be detected (set).

After the reference value is set, the change amount of the rotation angle θsa of the column 44a from the left end state or the right end state is detected by the relative angle sensor 75a (electric motor 44b) for detecting the rotation angle θsa of the column 44a. The absolute rotation angle θs of the column 44a can be calculated based on the same reference value and the same change amount by sequentially calculating based on the output value of the relative angle sensor 75b that detects the rotation angle of the output shaft 44ba. Computation (detection)
it can. The above is the CPU's absolute rotation angle θs of the column 44a.
Is the principle of calculating (detecting).

<Actual Operation> Next, the steering wheel operating device 1
11 is a flowchart showing a routine executed by the CPU of the microcomputer 71 for the actual operation of the absolute rotation angle detection device (steering wheel steering angle detection device for a vehicle) according to the third embodiment mounted on the No. 0. Also, description will be made with reference to FIG.

The CPU uses the absolute rotation angle θs shown in FIG.
The driver performs a routine to set the reference value of the ignition switch (not shown) from "OFF" to "ON".
Execute only once immediately after changing to. Therefore, the driver turns the ignition switch from "OFF" to "ON".
If changed to, the CPU starts the process from step 1100 and proceeds to step 1105 to change the signal Sa supplied to the throttle valve opening control device 60 to “accelerator OFF”.
The signal Sb supplied to the brake fluid pressure generation device 51 is fixed to the signal corresponding to "brake ON".

Therefore, thereafter, the throttle valve opening control device 60 maintains the state in which the throttle is closed,
The brake fluid pressure generation device 51 provides a wheel fluid cylinder WCf of each wheel with a brake fluid pressure equal to or higher than a predetermined value capable of maintaining the vehicle in a stopped state even when the brake pedal BP is released.
l, WCfr, WCrl and WCrr will continue to be supplied. As a result, the state in which the vehicle can be kept stopped during the execution of this routine continues.

Next, the CPU proceeds to step 1110 to supply the signal Ss to the electric motor 44b to cause the steering wheel Tfl,
The Tfr is automatically steered to the maximum left steering angle. To determine whether the steered wheels Tfl and Tfr have been steered to the left maximum steering angle, the left stopper 43L of the tie rod 43 is fixed by the fixing member 80.
Is performed based on a sensor that detects whether or not the left end portion 80L of the fixed member 80 is in contact with the left end portion 80L of the fixed member 80. Determined to be complete, step 1115
Proceed to. The driver may manually steer the steered wheels Tfl and Tfr to the maximum left steering angle.

At step 1115, the CPU sets the value of the absolute rotation angle θs of the column 44a in the left end state to the minimum value (design value) of the absolute rotation angle range stored in advance in the ROM-- N (“-720 °”, reference value)
Set to. As a result, the absolute rotation angle θs of the column 44a
The reference value of is set.

Next, the CPU proceeds to step 1120,
The variable K is set to "0", and step 1125 is executed.
Then, the reference angle θref is set to the value of the rotation angle θsb of the output shaft 44ba at the present time (when the column 44a is in the left end state). Here, the variable K and the reference angle θref are values used in an absolute rotation angle θs calculation routine, which will be described later, which is repeatedly executed after the end of this routine, and these processes are initially performed for the variable K and the reference angle θref. It is executed to give a value.

Next, the CPU proceeds to step 1130 to cancel the fixing process of the signals Sa and Sb executed in step 1105. Therefore, after this, the signal Sa
Is a signal corresponding to the accelerator opening degree θa of the accelerator pedal AP, and the signal Sb is a signal corresponding to the pedaling force Fb of the brake pedal BP. Therefore, the throttle valve opening control device 60 adjusts the throttle opening according to the accelerator opening θa, and the brake fluid pressure generation device 51 provides the brake fluid pressure according to the pedaling force Fb to the wheel cylinders WCfl and WC of each wheel.
will be supplied to fr, WCrl and WCrr. As a result, the state in which the vehicle can be maintained in the stopped state ends. Then, the CPU proceeds to step 1195 to end the present routine.

After completion of the reference value setting routine for the absolute rotation angle θs, the CPU repeatedly executes the routine for calculating the absolute rotation angle θs shown in FIG. 12 every time a predetermined time elapses. Therefore, when the predetermined timing comes, the CPU starts the process from step 1200, and proceeds to step 1205.
Proceeding to 1210, whether the value of the rotation angle θsb of the output shaft 44ba has changed from “360 °” to “0 °” and whether the value of the rotation angle θsb has changed from “0 °” to “360 °”. It is determined whether or not.

Then, the CPU determines that the value of the rotation angle θsb is “3.
If it has changed from "60 °" to "0 °", step 12
Proceed to step 15, and add K to the current value of K and add 1 to K.
If the value of the rotation angle θsb has shifted from “0 °” to “360 °” after setting to 1, the process proceeds to step 1220 and “1” is subtracted from the current value of K. After setting the value to K, the process proceeds to step 1225, and the value of the rotation angle θsb is also “0 °” from “360 °” to “0 °”.
If it has not changed from "360 °" to "360 °", the process proceeds to step 1225 while maintaining the current K value.

When the value of the rotation angle θsb shifts from “360 °” to “0 °”, in this example, the output shaft 44ba
However, the column 44a is in the left end state (the value of the absolute rotation angle θs is “-
720 ° ”) corresponding to the rotation of the column in the direction in which the value of the absolute rotation angle θs increases (the direction in which the output shaft 44ba rotates counterclockwise when viewed from the driver). 44a is in the right end state (the same absolute rotation angle θs
Occurs 4 times in total (see FIG. 6) until the value of is 720 °).

Further, the value of the rotation angle θsb changes from "0 °" to "3".
In the case of shifting to "60 °", in this example, the output shaft 44ba
However, the column 44a is in the right end state (the value of the absolute rotation angle θs is “7
20 ° ”), it occurs every one rotation in the direction in which the value of the absolute rotation angle θs decreases (the direction in which the output shaft 44ba rotates clockwise as viewed from the driver) from the corresponding state, and the column 44a Occurs 4 times in total until the state reaches the left end state (the value of the absolute rotation angle θs is “−720 °”) (see FIG. 6).

Immediately after the execution of the reference value setting routine for the absolute rotation angle θs shown in FIG. 11 described above, the value of K is “0” (see step 1120). By repeatedly executing the processing up to step 1220, K becomes the output shaft 44ba.
However, at the present time, in the direction in which the absolute rotation angle θs increases from the state corresponding to when the column 44a is in the left end state (the output shaft 44ba is counterclockwise when viewed from the driver).
It is a value (an integer of "0" or more and "4" or less) indicating how many times one rotation (360 ° rotation) is performed.

When the CPU proceeds to step 1225, the rotation angle θ of the output shaft 44ba from the time when the output shaft 44ba is in the state corresponding to when the column 44a is in the left end state.
The change Δθsb (cumulative change from the same state) of sb is calculated. Specifically, the change Δθsb is calculated by the relative angle sensor 75b.
The value of the reference angle θref set in step 1125 of FIG. 11 described above is subtracted from the value of the rotation angle θsb of the output shaft 44ba which is the output value at the present time, and the value after the subtraction is set to “360 It is calculated by adding a value obtained by multiplying "°" by K.

Next, the CPU proceeds to step 1230 to calculate (detect) the absolute rotation angle θs of the column 44a at the present time. More specifically, the change amount of the rotation angle θsa of the column 44a (cumulative change amount from the same state) since the column 44a is in the left end state is the rotation of the output shaft 44ba relative to the rotation of the column 44a. Considering that the ratio (second rotation ratio) is “5/4”, the above Δθ
It is a value obtained by multiplying sb by "4/5". Therefore, the absolute rotation angle θs of the column 44a at this time is calculated by adding a value obtained by multiplying Δθsb by “4/5” to the value of the reference value “−N”. Then, the CPU proceeds to step 1295 to end the present routine tentatively.

As described above, the absolute rotation angle detecting device according to the third embodiment (steering wheel steering angle detecting device for a vehicle) does not use an absolute angle sensor, and the absolute rotation angle exceeds 360 °. Within the angular range (-720 ° ≤ θs <720
It is possible to detect the absolute rotation angle θs of the column 44a that changes with the rotation angle θss of the steered wheels Tfl and Tfr.
Was able to be detected.

In the third embodiment, the relative angle sensor 75b for detecting the rotation angle θsb of the output shaft 44ba of the electric motor 44b detects the change in the rotation angle θsa of the column 44a. The change amount of the rotation angle θsa of the column 44a may be directly detected by the relative angle sensor 75a that detects the rotation angle θsa of.

In this case, "θsb" in step 1125 of the routine shown in FIG.
Step 1205, Step 12 of the routine shown in FIG.
10 is replaced with “θsa” and step 1225 is replaced with “Δθsa ← θsa−θref + K × 3.
Instead of 60 °, step 1230 is replaced by “θs ← Δθsa
-N "instead of the routine shown in FIG.
The routine shown in 1 may be executed.

(Modification of Third Embodiment) In the third embodiment, when setting the above-mentioned reference value of the absolute rotation angle θs of the column 44a, the column 44a is in the right end state and the left end state. The (cumulative) change amount of the rotation angle θsa of the column 44a is calculated, and the half value (absolute value) of the change amount becomes the same reference value (absolute value) of the absolute rotation angle θs of the column 44a. May be used to set the same reference value.

In this case, the CPU executes a routine for setting the reference value of the absolute rotation angle θs shown in FIG. 13 instead of the routine for setting the reference value of the absolute rotation angle θs shown in FIG. , It is executed only once immediately after the driver changes the ignition switch (not shown) from “OFF” to “ON”.

Therefore, when the driver changes the ignition switch from "OFF" to "ON", the CPU starts the processing from step 1300, and proceeds to step 1305.
Then, as in step 1105 in FIG. 11 described above, a vehicle stop maintaining instruction is issued to bring the vehicle into a stopped state.

Next, the CPU proceeds to step 1310 to automatically steer the steered wheels Tfl and Tfr to the right maximum steering angle, and then proceeds to step 1315 to rotate the output shaft 44ba in the right end state. The value of the angle θsb is set in the variable θ1. Then, the CPU proceeds to step 1320 to automatically steer the steered wheels Tfl and Tfr to the maximum left steering angle, and then proceeds to step 1325 to determine the value of the rotation angle θsb of the output shaft 44ba in the left end state. Is set to the reference angle θref.

Next, the CPU proceeds to step 1330 to calculate the cumulative change θn of the rotation angle θsb of the output shaft 44ba when the column 44a moves from the right end state to the left end state. Specifically, the cumulative change amount θn is calculated in the column 44a.
Output shaft 44ba while moving from the right end state to the left end state
Is known to perform one rotation (rotation of 360 °) four times, the value of the reference angle θref is subtracted from the value of the variable θ1, and the value obtained by subtracting “360 °” is 4 It is calculated by adding the multiplied value.

Then, the CPU proceeds to step 1335 to set the reference value of the absolute rotation angle θs of the column 44a in the left end state. Here, considering that the rotation ratio (second rotation ratio) of the rotation of the output shaft 44ba with respect to the rotation of the column 44a is “5/4”, when the column 44a moves from the right end state to the left end state, Column 44a
Since the cumulative change in the rotation angle θsa of is θn × 4/5, this reference value is calculated as “−θn / 2 × 4/5”.

Next, the CPU proceeds to step 1340 to set the initial value "0" to the variable K, proceeds to step 1345, cancels the vehicle stop maintaining instruction executed in step 1305, and then proceeds to step 1395. The process proceeds to end this routine.

After the above-described reference value setting routine for the absolute rotation angle θs shown in FIG. 13, the CPU executes the routine for calculating the absolute rotation angle θs shown in FIG. 12 every time a predetermined time elapses. To repeat. in this case,
Step 1230 of the routine shown in FIG. 12 is executed with “θs ←
4/5 × Δθsb−θn / 2 × 4/5 ”,
The routine shown in FIG. 12 is executed.

In the third embodiment, column 4 is used.
An absolute angle sensor that can directly detect the absolute rotation angle θs of 4a may be provided. In this case, the ignition switch is
If the absolute angle sensor is functioning normally when it is changed from "FF" to "ON", the CPU uses the absolute rotation angle θs of the column 44a at that time as a reference value, and the rotation angle of the column 44a thereafter. The absolute rotation angle θs of the column 44a is calculated by detecting the cumulative change from the same reference value by the relative angle sensor 75a or 75b (hence, the column 44a).
The operation that puts a in the leftmost state or the rightmost state is not executed).

On the other hand, the ignition switch turns "OF".
If the absolute angle sensor is out of order at the time of changing from “F” to “ON”, CP according to the third embodiment described above.
U calculates the absolute rotation angle θs of the column 44a by operating the column 44a to the left end state or the right end state.

Although the first to third embodiments of the present invention have been described above, the embodiments of the present invention are not limited to these, and may be appropriately modified within the scope of the claims. It goes without saying that it can be changed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a vehicle equipped with a steered wheel operation device that includes a steered wheel steering angle detection device for a vehicle that includes an absolute rotation angle detection device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of the operation system actuator shown in FIG.

3 is a schematic configuration diagram of the steering actuator shown in FIG. 1. FIG.

FIG. 4 is a flowchart showing a steering control routine executed by a CPU of the electric control device shown in FIG.

5 is a graph showing a relationship between an estimated vehicle speed V and a steering angle ratio R used when the CPU of the electric control device shown in FIG. 1 calculates a steering angle ratio R. FIG.

6 is a first output value (θsa) of the relative angle sensor 75a corresponding to each value of the absolute rotation angle of the column shown in FIG.
6 is a graph showing a transition of the second output value (θsb) of the relative angle sensor 75b.

7 is a flowchart showing an absolute rotation angle calculation routine executed by a CPU of the electric control device shown in FIG.

8 is a map used by the CPU of the electric control device shown in FIG. 1 when executing the absolute rotation angle calculation routine shown in FIG. 7.

FIG. 9 is a schematic configuration diagram of a steering actuator of a steering wheel steering angle detection device for a vehicle including an absolute rotation angle detection device according to a second embodiment of the present invention.

FIG. 10 is a first output value (θsa) of a relative angle sensor 75a and a second output value (θsb) of a relative angle sensor 75b corresponding to respective absolute rotation angle values of a column according to a modification of the second embodiment. ) Is a graph showing the transition.

FIG. 11 is a flowchart showing a reference value calculation routine of an absolute rotation angle, which is executed by a CPU of a steering angle detection device for a steered wheel of a vehicle including an absolute rotation angle detection device according to a third embodiment of the present invention.

FIG. 12 is a flowchart showing an absolute rotation angle calculation routine executed by a CPU of a steered wheel steering angle detection device for a vehicle including an absolute rotation angle detection device according to a third embodiment of the present invention.

FIG. 13 is a flowchart showing a reference value calculation routine of an absolute rotation angle executed by a CPU of a steering angle detection device for a steered wheel of a vehicle including an absolute rotation angle detection device according to a modification of the third embodiment of the present invention. Is.

[Explanation of symbols]

20 ... Operation system input section, 30 ... Operation system actuator, 4
0 ... Front wheel steering mechanism section, 44 ... Steering actuator, 44
a ... column, 44b ... electric motor, 44ba ... output shaft, 44
c ... Electric motor, 44ca ... Output shaft, 70 ... Electric control device, 71 ... Microcomputer, 75a ... Relative angle sensor, 75b ... Relative angle sensor.

Claims (5)

[Claims] 1. An absolute rotation angle detection for detecting the absolute rotation angle of an absolute rotation angle detection object, wherein an absolute rotation angle, which is a cumulative rotation angle from a reference angle, changes within a predetermined absolute rotation angle range exceeding 360 °. A first rotating body that rotates at a first rotation ratio with respect to the rotation of the absolute rotation angle detection body; and a second rotation ratio that rotates with respect to the rotation of the absolute rotation angle detection body. And a first output value that changes within a predetermined output range according to a rotation angle of the first rotating body, and the first output value is any one value within the same output range. First rotation angle detection means for generating a first output value set so that a plurality of the absolute rotation angles of the absolute rotation angle detection body correspond to A first value that changes within a predetermined output range according to the rotation angle of the second rotating body 2 output values, the absolute rotation angle of the absolute rotation angle detection object corresponding to when the second output value becomes any one value within the output range is a plurality within the absolute rotation angle range. Second rotation angle detecting means for generating a second output value set to exist, the first rotation angle detecting means and the second rotation angle detecting means are provided for the absolute rotation angle detecting body. When the absolute rotation angle changes within the absolute rotation angle range, the combination of the first output value and the second output value corresponding to each value of the same absolute rotation angle may be the same combination. The absolute rotation angle detection device is set so that it does not exist, and includes a detection unit that detects an absolute rotation angle of the absolute rotation angle detection body based on a combination of the first output value and the second output value. . 2. The absolute rotation angle detection device according to claim 1, wherein the first rotation ratio and the second rotation ratio have different values. 3. The absolute rotation angle detection device according to claim 2, wherein both the first rotation ratio and the second rotation ratio have a value of 1 or more. apparatus. 4. An absolute rotation angle detection for detecting the absolute rotation angle of an absolute rotation angle detection object, wherein an absolute rotation angle, which is a cumulative rotation angle from a reference angle, changes within a predetermined absolute rotation angle range exceeding 360 °. A device that rotates to generate an output value that changes according to the rotation of the absolute rotation angle detection body or the rotation of the rotation body that rotates at a predetermined rotation ratio relative to the rotation of the absolute rotation angle detection body. Angle detection means, based on at least the output value of the rotation angle detection means in a state where the absolute rotation angle detection body is at the end of the rotatable range, when the absolute rotation angle detection body is in the same state While setting the reference value of the absolute rotation angle, the same reference value,
The absolute rotation angle of the absolute rotation angle detection body is detected based on the change in the rotation angle of the absolute rotation angle detection body from the same state calculated based on the output value of the rotation angle detection means. Absolute rotation angle detecting device having a detecting means for 5. The vehicle rotates from a reference angle according to the turning angle of the steered wheels of the vehicle from a reference steering angle at which the vehicle goes straight, and the absolute rotation angle, which is a cumulative rotation angle from the reference angle, is 360 °. An absolute rotation angle detection body that changes within a predetermined absolute rotation angle range that exceeds the absolute rotation angle detection device, and the absolute rotation angle detection device according to any one of claims 1 to 4. A steering wheel of a vehicle that detects the absolute rotation angle of the detection body by using the absolute rotation angle detection device and that detects the turning angle of the steering wheel of the vehicle based on the detected absolute rotation angle. Steering angle detection device.