JPS63186102A - Steering angle detector - Google Patents

Abstract

PURPOSE:To allow a one-rotation potentiometer to function normally as a multirotation type by deciding whether or not a 1st current collection member contacts a resistor finely or not, and precluding the malfunction of steering angle arithmetic. CONSTITUTION:When a steering wheel 2 is rotated for steering, a shaft member rotates on a supporting member, and a ring-shaped resistor, the shaft member, and 1st and 2nd current collection members 60a and 60b fixed to the other side of the supporting member come into slide contact, so that the 1st and 2nd current collection members 60a and 60b outputs out-of-phase detection signals corresponding to the steering angle. Further, a fine contact state deciding means (arithmetic processor, etc.) positions the 1st current collection member 60a at the border part of the electric blind zone of the ring-shaped resistor according to the detection signals of the 1st and 2nd current collection members 60a and 60b and when it is decided that the member is in slight contact with the ring-shaped resistor, a steering angle correcting value arithmetic means (microcomputer) calculates the correcting value for a steering force according to the detection signal of the 2nd current collection member 60b.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a multifunction device that detects the steering angle of a steering wheel that rotates multiple times using a ring-shaped one-turn potentiometer used in vehicles such as automobiles. Regarding the improvement of a rotary steering angle detection device, in particular, a current collecting member that slides on a ring-shaped potentiometer that partially has an electrical dead zone is located at the boundary between the electrical dead zone and the resistor, and the current collecting member is located at the boundary between the electrical dead zone and the resistor. The present invention relates to a steering angle detection device that prevents misdetection of a steering angle caused by contact.

[Conventional technology]

As a conventional multi-rotation type steering angle detecting device as described above, for example, Japanese Patent Application No. 61-1981 filed by the present applicant is known.
There is one disclosed in the specification of No. 1005.

In this conventional device, a disk-shaped substrate (shaft member) is fixed to the outer periphery of a stub shaft that rotates together with the steering wheel, and a ring-shaped electrical resistance member having a part of the electrical dead zone is attached to one surface of this disk-shaped substrate. The other end sides of the first and second current collecting members, one end of which is fixed to the gear box (supporting member) side, are brought into sliding contact with the ring-shaped electrical resistance member and the electrical dead zone. When the current collecting member is in contact with the electrical resistance member, the steering angle is calculated based on the detection signal of the first current collecting member, and when the first current collecting member is in contact with the electrical dead zone, A correction value for the steering angle is calculated based on the detection signal of the second current collecting member.

In addition, the above-mentioned conventional device transmits the steering torque input from the steering wheel to the same side or the opposite side of the one side on which the potentiometer for detecting the steering angle is printed on the disk-shaped substrate. A resistor is printed to detect the torsion angle of the torsion bar connected between the stub shaft and the pinion shaft, which is the relative rotation angle between the stub shaft and the pinion shaft. I'm trying to detect it.

[Problem that the invention seeks to solve]

However, in such a conventional steering angle detection device, as shown in FIG. 12, the current collecting member is actually electrically connected to the resistor (area AL and area A When located at the boundary of the Fuwazai zone (Area C), especially at the boundary between the maximum voltage side end of the resistor (Area AM) and the electrical Fuwazawa zone (Area C), the steering speed should be reduced to almost 0. Then, there is an area B where the current collecting member makes slight contact with the resistor and the detection signal slopes from the maximum voltage to 0 during a change in steering angle of about 1°. A voltage value equal to voltage a may be detected in area B.

However, in the conventional device, the voltage value caused by such a slight contact between the current collecting member and the resistor was not distinguished from the voltage value a caused by normal contact. If this is detected, the subsequent steering angle calculation process will malfunction, and in particular, the zone that determines the number of rotations of the steering wheel relative to the ring potentiometer will be incorrectly judged. There was a problem in that once the value was read, all subsequent calculations of the absolute steering angle would be incorrect.

This invention was made by focusing on such conventional problems, and the current collecting member is located at the boundary between the resistor and the electrical dead zone of the ring-shaped potentiometer, and is in slight contact with the resistor. It is an object of the present invention to provide a steering angle detection device that distinguishes a detection signal in a steering wheel, prevents malfunction of steering angle calculation due to such a detection signal, and enables a single-turn potentiometer to function normally as a multi-turn potentiometer. It is something.

[Means for solving problems]

Therefore, as shown in FIG. 1, the steering angle detection device of the present invention includes: a shaft member that rotates together with the steering wheel; a support member that rotatably supports the shaft member; and an inside of the shaft member and the support member. a ring-shaped resistor having an electrically dead zone in a part, which is fixed concentrically with the shaft member on one side; and a ring-shaped resistor having an electrical dead zone in a part thereof, which is fixed in phase with the other of the shaft member and the support member; First and second current collecting members that are in sliding contact with the side resistor and the electrically unstable band; Steering angle calculation means that calculates the steering angle of the steering wheel based on the detection signal of the first current collecting member; First collection A steering angle detection device comprising: a steering angle correction value calculating means for calculating a steering angle correction value based on a detection signal of the second current collecting member when the electric member is in contact with the electrical dead zone; Based on the detection signals of the current collecting member and the second current collecting member,
The first current collecting member is located at the boundary between the resistor and the electrical dead zone and is in slight contact with the resistor. When it is determined that the first current collecting member is located at the boundary between the resistor and the electrical dead zone and is in slight contact with the resistor, the steering angle correction value calculating means calculates the value of the second current collecting member. The present invention is characterized in that a correction value for the steering angle is calculated based on the detection signal.

[Effect]

When the steering wheel is rotated, the shaft member rotates with respect to the support member. A ring-shaped resistor having an electrical dead zone in a part fixed to one of the shaft member and the support member is in sliding contact with first and second current collecting members fixed to the other of the shaft member and the support member. , detection signals whose phases are shifted according to the steering angle are obtained from the first and second current collecting members. When the first current collecting member is in contact with the resistor, the steering angle of the steering wheel is calculated by the steering angle calculation means based on the detection signal of the first current collecting member, and the first current collecting member is in the electrical dead zone. When the second current collecting member is in contact with the second current collecting member, the steering angle correction value calculation means calculates a correction value of the steering angle based on the detection signal of the second current collecting member.

Further, based on the detection signals of the first current collecting member and the second current collecting member, the first current collecting member is located at the boundary part of the electrically unstable zone of the resistor and slightly contacts the resistor by the slight contact state determination means. It is determined whether or not they are in contact, and the first current collecting member is located at the boundary between the resistor and the electrically unstable zone and is in slight contact with the resistor by the slight contact state determining means. When it is determined that there is a correction value for the steering angle, the steering angle correction value calculation means calculates a correction value for the steering angle based on the detection signal of the second current collecting member.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Note that, like the conventional device mentioned at the beginning, this embodiment has a function of detecting steering torque in addition to the function of detecting the steering angle, and furthermore, it has a function of detecting steering torque using the rotational force of the electric motor. This is applied to an electric power steering device that assists the angle.

First, the configuration will be explained.

In FIGS. 2 and 3, reference numeral 1 denotes a steering shaft. A steering wheel 2 is attached to the upper end of the steering shaft, and a stub shaft 1a serving as an input shaft forming a part of the steering shaft 1 is attached to the lower end of the steering shaft. are spline-coupled, and the lower part of this stub shaft 1a is inserted into a gear box 4 of a rank-and-pinion type steering gear 3.

The stub shaft 1a passes through a hole in a ring-shaped bearing holder 5 that closes an opening 4a on the steering wheel 2 side of the gear box 4, and a bearing 6 is fitted into the hole.
It is rotatably supported by the bearing holder 5 via. The bearing holder 5 is positioned on the gear box 4 by a snap ring 7, and the stub shaft 1a
An oil seal 8 seals between the two.

Further, in the gear box 4, a pinion shaft 9 is disposed coaxially below the stub shaft 1a as an output shaft integrally provided with a pillar-on gear 9a. Two fitted bearings 1
0.11, a pinion shaft 9 is rotatably supported by the gear box 4. The pinion gear 9a is
In addition to meshing with the rack 12a of the rack shaft 12 in the gear box 4, tie rods 13.13 are swingably connected to both ends of the rack shaft 12, and wheels 14.14 are connected to the outside of the tie rods 13.13. A knuckle 15.15 that rotatably supports the is pivotally connected.

16 denotes two bearings 1 externally fitted on the pinion shaft 9.
0.11 is a nut for applying a preload, 17 is a cap screwed into a screw hole provided in the gear box 4 for attaching and detaching the nut 16, 18 is a rank retainer, and 19 is an adjustment bolt.

Further, the stub shaft 1a has a pipe shape, and a torsion bar 20 as a spring member is inserted into the inside of the stub shaft 1a, and the end of the torsion bar 20 on the steering wheel 2 side and the stub shaft 1a are fastened with a pin 21. Both rotate together, and the opposite end of the torsion bar 20 is connected to the stub shaft l of the pinion shaft 9.
It is inserted into the axial hole 9b facing the end face on the a side, and is fastened to the pinion shaft 9 by the pin 22, so that the two rotate together. Furthermore, a hub 9c that projects toward the stub shaft 1a and a flange 9d that projects radially outward are formed at the end of the pinion shaft 9 on the stub shaft la side, and the stub shaft 1a passes through a hole in the hub 9c.
A needle roller bearing 23 is interposed between the lower end of the hub 9C and the hub 9C.

A notch 9e is provided in the hub 9C of the pinion shaft 9, and a protrusion 1b provided at the lower end of the stub shaft 1a is inserted into the notch 9e. A stopper is formed to prevent the relative rotational displacement between the stub shaft 1a and the pinion shaft 9 from exceeding a predetermined value (for example, about 5 degrees). Further, a worm wheel 24 is fitted on the outside of the hub 9C, and a screw 25 that passes through the worm wheel 24 and screws into the flange 9d allows the worm wheel 24 and the pinion shaft 9 to rotate together. join to. A worm 26 rotatably supported by the gear box 4 is engaged with the worm wheel 24, and a rotating shaft of a motor 27 is connected to a shaft portion of the worm 26. A control device 3o, which will be described later, is connected to the motor 27, and the motor 27 is driven and controlled by a control signal output from the control device 30.

Further, on the outer periphery of the stub shaft 1a, a disc-shaped substrate 2 formed of a highly insulating material such as phenol resin is provided.
8 is fitted onto the outside and placed between the convex portion 1b and the bearing 6. On the radially inner side of this disk-shaped substrate 28, there is a convex portion 1b.
Boss 28a protruding to the side and boss 28 protruding to the bearing 6 side
b is formed, and metal bushes 29a and 29b are fitted onto both bosses 28a and 28b, respectively, and both metal bushes 29b on the bearing 6 side are fixed to the stub shaft 1a by caulking. , the stub shaft 1a and the disc-shaped substrate 28 rotate together and are fixed in the axial direction.

As shown in FIG. 4, a conductive plastic element (Cond.
uctive plastic element; hereinafter referred to as CP element. ), etc. 2 electrical resistance members 31°32
, a good electrical conductor 33.34 with a low resistance value equivalent to a slip ring connecting both electrical resistance members 31.32, and a good electrical conductor 35.36 arranged concentrically outside each electrical resistance member 31.32. printed. Electric resistance member 31
．． 32 are provided concentrically at 180 degrees apart from each other about the axis of the disc-shaped substrate 28, and these serve as resistance members for detecting steering torque, and as will be described later,
The torsion angle of the torsion bar 20, that is, the relative rotational displacement between the stub shaft 1a and the pinion shaft 9, which is proportional to the steering torque input to the steering wheel 2, is detected as a voltage value.

Furthermore, as shown in FIG. 5, on the surface of the disc-shaped substrate 28 on the bearing 6 side, an electrical resistance member 40 made of a CP element or the like is provided by cutting a part of the ring to form an electrically unstable zone C. Four electrically conductive conductors 41 completely continuous in the direction of a ring,
42, 43, and 44 are printed concentrically around the axis. The electrical resistance member 40 is a steering angle detection resistance member, and is located second from the inside, the innermost electrically conductive member 41 is a power supply line, and the third electrically conductive member from the innermost member 42 is an earth line.

One end of the electrical resistance member 40 for detecting the steering angle is connected to a good electrical conductor 41 for a power supply line through a terminal 41a, and the other end is connected to a good electrical conductor 42 for a ground line through a terminal 42a. The terminal 41a of the electrically conductive conductor 41 for the power line is connected to the electrically conductive conductor 34 for connection formed on the opposite side via the rivet 45, and the terminal 41a of the electrically conductive conductor 42 for the earth line
a is connected via a rivet 46 to a good electrical conductor 33 for connection formed on the opposite surface. Furthermore, from the inside 4
The electrically conductive conductor 43 located at the th position is connected to the electrically conductive conductor 36 for steering torque detection formed on the opposite surface via a rivet 47.
The electrically conductive conductor 44 located at the outermost side is connected via a rivet 48 to an electrically conductive conductor 35 for steering torque detection formed on the opposite surface.

Returning to FIG. 3, the aforementioned metal bushes 29a and 29
A rotary member 50 and a ring member 51 made of a highly insulating resin are rotatably fitted onto b, and a sixth Wave springs 52 and 53 each having a ring shape as shown in the figure are interposed, and the axial movement of the rotating member 50 toward the worm wheel 24 due to the biasing force of the wave spring 52 is snapped via a flat washer. In addition to being restricted by the ring 54, the axial movement of the ring member 51 toward the bearing 6 due to the biasing force of the wave spring 53 is restricted by the snap knob ring 55 via a flat washer.

The rotating member 50 has a protrusion 50a that protrudes toward the worm wheel 24, and a peripheral edge 50b that extends to cover the outside of the disk-shaped substrate 28 and the ring member 51.
A coupling pin 56, which is inserted into a hole provided in the worm wheel 24 and whose tip protrudes toward the bearing 6, is press-fitted into the hole a, thereby integrating the worm wheel 24 and the rotating member 50 in the rotational direction. A seal ring 57 that contacts the inner peripheral surface of the opening 4a of the gear box 4 is attached to the peripheral edge 50b of the rotating member 50, so that the lubricant stored on the worm wheel 24 side is transferred to the disk-shaped substrate. This prevents it from entering the 28 side.

Further, two comb-shaped current collecting members 58 and 59 are attached to the rotating member 50 at two locations, as shown in FIG. is in sliding contact with the electrical resistance member 31 for detecting steering torque and a good electrical conductor 35, and the current collecting piece at the tip of the other current collecting member 59 is in sliding contact with the electrical resistance member 32 for detecting steering torque and a good electrical conductor 36. .

Further, the ring member 51 is a projection 5a provided on the bearing holder 5.
This prevents the ring member 51 from rotating with respect to the bearing holder 5.

At six locations on the ring member 51, there are comb-shaped current collecting members 60a, 60b, 61, shaped as shown in FIG.
62, 63, and 64 are attached. The two current collecting members 60a and 60b are arranged so as to be in sliding contact with the electrical resistance member 40 for detecting the steering angle at positions rotated 180 degrees from each other, and when the steering wheel 2 is in the neutral position when the vehicle is traveling straight, One first current collecting member 60a is set to be located at the center of the electrical resistance member 40. The other four current collecting members 61, 62, 63, and 64 are arranged so as to be in sliding contact with the four electrically conductive members 41, 42, 43, and 44 individually.

These six current collecting members 60a, 60b, 61°62.6
3.64 is connected to the control device 30 via six harnesses 65.
and a power source 66 such as a battery, the electric circuit configuration of which is shown in FIG.

In FIG. 9, two fixed resistors 6 are installed before and after the power source 66 in series with the steering torque detection electric resistance member 31, 32 and the steering angle detection electric resistance member 40, respectively.
7.68 is provided, and by applying a potential difference to each electrical resistance member 31, 32.40 with a refixing resistor 67.68, when the electrical circuit is in a normal state, the output voltage according to the steering torque is , as shown in FIG. 10, changes between the maximum output value Tll and the minimum output value TL, and the output voltage according to the steering angle varies from the maximum output value V14AX to as shown in FIG. It is set to change up to the minimum output value VHIN.

That is, as shown in FIG. 10, the output voltage according to the steering torque varies from the maximum output value T corresponding to the maximum steering torque when turning right to the minimum output value TL corresponding to the maximum steering torque when turning left. It changes between. In this embodiment, two sets of electrical resistance members 31, 32 and current collecting members 58, 59 are provided, but this is done in consideration of the safety of steering torque detection, and as long as there is at least one set, Steering torque can be detected.

In addition, the output voltage according to the steering angle is shown in Figures 11 and 12.
As shown in the figure, there is an output voltage e (k) obtained from the first current collecting member 60a indicated by a solid line, and an output voltage f (k) obtained from the second current collecting member 60b indicated by a broken line. Here, k indicates the th sampling period in the microcomputer 70 included in the control device 30. The output voltages e(k) and f(k) have the same shape with a phase difference of 180 degrees, and the output voltages e(k) and f(k) have the same shape with a phase difference of 180 degrees, and
In other words, the same output waveform is exhibited every time the steering wheel 201 rotates.

If the area is defined here, the first and second current collecting members 60
When the current collector pieces a and 60b are in contact with the electrical resistance member 40 shown in FIG. 5, e (k) and f (k) change from the minimum output voltage VMIN = 0.5 V to the maximum output voltage VM.
When AX changes between 4.5 V and the current collector piece is in the middle position of the electrical resistance member 40, e(k) and r(k)
becomes e+=2.5v. And e(k) and f(k
) is VMIN~e1. The steering angle range exhibiting values between I is defined as area AL, and the steering angle range exhibiting values between eH-■ and 4AX is defined as area A. In addition, the minimum output voltage VM
eL=1.4V between IN and intermediate voltage eH, and eH=3.6 between intermediate voltage eM and maximum output voltage VW□
Set V respectively. Further, when the current collector piece is in the electrical dead zone C between the electrical resistance members 400 in a range of about 10 to 20 degrees, the output voltage becomes 0, and this area is designated as C.

When the current collector piece is in slight contact with the electrical resistance member 40 at the boundary between the end of the electrical resistance member 40 on the maximum output voltage side and the electrical dead zone C, the output voltage is at the maximum value V.
Although the steering angle varies between WAX and the minimum value VMIN, the range of the steering angle that exhibits this slight contact state is about 1 degree, and this area is designated as B.

Furthermore, when the zone is defined, when the vehicle is traveling straight and the steering wheel 2 is at a steering angle of 0 degrees, which is the neutral position of steering, the first current collecting member 60a is at the intermediate position of the electrical resistance member 40. The mutual rotational positions of the steering wheel 2, the first current collecting member 60a, and the electrical resistance member 40 are set as shown in FIG. From the steering angle position on the boundary of area AL, turn right 3
Zone (0) when it is within the range of 60 degrees, and zone (
0), turn further to the right to create a 360 degree zone (+I
The zone (+2) is a 360 degree range by turning further to the right than the L zone (+1). Also, by turning further to the left from zone (0), the range of 360 degrees is zone (-1), zone (-
Turn further left than 1) to create a 360 degree zone (-2
).

Each zone is located at the boundary position between area C and area AL, that is, (-180±360n) degrees (where n=0.1.2
) to the right by C/2 as the starting and ending points,
Area AL% as you steer to the right from the start point to the end point
Pass through area AH% area B and area C.

As described above, the second current collecting member 60b is positioned 180 degrees opposite to the first current collecting member 60a.

Further, the output value e(k) by the first current collecting member 60a is the main detection value for detecting the steering angle, and the output value e(k) by the first current collecting member 60a is the main detection value for detecting the steering angle.
The output value f (k) is used as a sub-detection value to obtain a steering angle correction value as an auxiliary when the main detection value e (k) is in area B or C and an accurate steering angle value cannot be detected. do.

Returning to FIG. 9, 30 is a control device, and this control device 30 includes a microcomputer 70 and a first current collecting member 6.
An A/D converter 71 that converts an analog voltage signal from 0a into a digital signal, an A/D converter 72 that converts an analog voltage signal from the second current collecting member 6Qb into a digital signal, An A/D converter 73 that converts the analog voltage signals from the current collecting members 58 and 64 into digital signals, and an A/D converter that converts the analog voltage signals from the current collecting members 59 and 63 into digital signals. 74.

The microcomputer 70 includes at least an interface circuit 75, an arithmetic processing unit 76, and a RAM.

The interface circuit 75 includes a storage device 77 such as a ROM, and A/D converters 71 to 74 are connected to the interface circuit 75.

The arithmetic processing unit 76 connects the first current collecting member 60a, the second current collecting member 60b, and the current collecting member 5 via the interface circuit 75.
8 and the detection signals of the current collecting member 59 are read, and based on these, calculations and other processing to be described later are performed. Further, the storage device 77 stores predetermined programs necessary for the execution of these processes in the arithmetic processing unit 76, and sequentially stores processing results of the arithmetic processing unit 76.

Next, the operation of the above embodiment will be explained.

When the ignition switch is turned on, the control device 30
The power is turned on, and the first power construction member 60a is turned on.

Detection signals from the second current collecting member 60b, the current collecting member 58, and the current collecting member 59 are supplied to the ear face circuit 75 of the microcomputer 70.

FIG. 13 shows the procedure of processing executed in the microcomputer 70. This process is preferably executed as a timer interrupt at predetermined intervals.

Here, to explain the basic outline of the steering angle detection processing operation, the sign of any function F (k) (i.e. +
When sgn (F(k)) is expressed as sgn (F(k)),
To determine the steering angle area, sgn Ce(k)-e(k-1)) = sgn
(f(k)-f(k-1)) and e(k)>
When e H, area Ao and sgn (e(
k)-e(k-1)) = sgn(f(k)-
f(k-1)) and e(k)<eH, the area is AL, and sgn(e(k)-e(k-1)
) = −sgn (f(k)−f(k−1
)), it is area B, and e(k)-e(k-1)=O and f(k)-f(k-1)
≠0 or e(k)-e(k-1)≠O and f (k)-f (k-
1) When = 0, it is area C.

Also, the zone is -180@+C/2≦e(k)<180”+C/2
If so, it is zone (0), and 180'+C/2≦e(k)<540' +C/2
If 540°+C/2≦e(k) then it is zone (2), and if -540'+C/2≦e(k)<-180'+C/
2, it is zone (-1), and if e(k)<-540@+C/2, it is zone (-2).

Furthermore, the zone change is based on the past value of e(k) (e(k
-1)) When expressing the latest value among the values in area A (that is, area A and A11) in eALA quality, e A LAsT = A L to e (k) =
A ) I and e(k)>e, 4, it is determined that zone - zone - 1, that is, the zone has changed by one to the left-cut side, and e A LAST = A H to e ( k) = A L, and e(k)<eL
At time O, it is determined that zone - zone +1, that is, the zone has been changed by one to the right cutting side.

With this zone changing method, malfunctions will not occur unless the steering angle changes by about 90 degrees or more during one sampling time. Furthermore, with control using a microcomputer, one sampling time can be less than Ioms, so there is almost no risk of malfunction in this method.

To explain the above-mentioned operation in detail, in FIG. 13, first, in step (2), zone=O1e A LA!
IT=O1 Main detection value e(
0)-0, opening value f(0) by the second current collecting member 60b
= 0 and steering angle value θ(0) = O, respectively, are set as initial values.

Next, in step (2), the main detection value e (k) and the uncorked output value f (k) in the current sampling period are read, and then the process moves to step (2), where the value of e (k) read in step (2) and the memory are stored. The difference between the main detection values e(k-1) in the previous sampling period stored in a predetermined storage area of the device 77 is calculated, and the difference value is set as Δe(k). Similarly, in step (3), The opened value f in the previous sampling cycle is stored in the predetermined storage area of the storage device 77 and the read value of f (k).
(k-1), and calculate the difference value as Δf (k
).

Next, proceed to step ■, and calculate the product of the difference value Δe (k) and Δf (k) calculated in step ■, Δe*f=Δ
Calculate e(k)*Δf(k), then step ■
Check whether the product Δe*f is positive or not.

If Δ6*f>O in step ■, then this is Δe (k
) and Δf (k) have the same sign, indicating that it is area A as shown in step ■, and then in step ■, e (k) read in step
It is checked whether it is larger than M, and if e (k)≦e14, the area is AL as shown in step (2).

Next, the process moves to step ■, and it is checked whether or not eA1□1=0. If eAtAsA≠0, then the process moves to step 0, and e ALAS? = 8 laps to see if it is AL or not
c% e AL713y+A L or e A163
If y = AH, then move to step ■ and e (
Check whether e(k) is smaller than a predetermined value el, and
If < e L, it is determined that the zone has changed from A□ to AL to the right cutting side, and in the next step @, the zone is set to - zone +1, and then the process moves to step 0.

Also, if eALA3A=0 in step ■, or if eAtast=AL in step [phase], or if I3ALAST=AM but e
If (k)≧e, it is assumed that there is no change in the zone, and step @ is skipped, and the process proceeds to step 0.

In step 0, eAtAs=AL is updated and stored, and then in step 2, based on the main detection value e (k) and the zone updated in step @ or not updated in step @, the same as described above is performed. Then, the steering angle value θ(k) is calculated.

That is, when zone = 0, θ(k)-K (e(k)-eM) When zone = 1, θ(k) = (180+C/2)+K [e(k)-V
Ht, 4) When zone = 2, θ(k)□ (540+C/2)+K (e(k)-V
s+s) When zone=-1, θ(k)□-(180+C/2)+K(e(k)-V
, Ax) When zone=-2, θ(k)=-(540+C/2)+K(e(k)-V
, Ax), the steering angle θ(k) is calculated and detected.

Here, K is K(VMAX − VMIN )=(36
0-C) 'T: defined as the conversion coefficient between output voltage and steering angle.

In addition, if e(k)>e in step (2), the area is AH as shown in step (2), and in this case, the process moves to step [phase] and e AtAst=O. Check whether "ALASf≠O", then proceed to step 0, e A LAST = A I4
Check 8 times whether eALast≠A, that is, e A
If LAst = A, then move to step [phase] to check whether e (k) is greater than a predetermined value eH, and if e (k) > e u, this means that the zone is At
It is determined that the change has been made from AM to the left cutting side, and in the next step [phase], the zone is changed to zone-r1, and then the process moves to step [phase].

Also, if e AL7137'=Q in step [phase], or e ALA! in step @. 17 = AM, or if eALAs = AL in step [phase] but e (k)≦eH, it is assumed that there is no zone change, skip step [phase], and go to step 0. Transition.

In step [phase], eAL□A=Ai is updated and stored,
Then in step [phase] 1. Main detection value e (k)
and updated in step [phase] or step 0
The steering angle value θ(k) is calculated based on the zone that was not updated in the same manner as described above.

If it is determined in step ■ that Δ6 * f > 0, then proceed to step ■ and check whether Δe*f = 0. If No, this is Δe (k)
Since and Δf (k) have different signs, it is determined that either e (k) or f (k) is in area B, as shown in step [phase], and then the process moves to step [phase]. do.

If it is determined that Δe*f=Q in step ■,
Next, move to step 0 and check whether Δe(k)=0 or not, and if Δe(k)≠0, this is Δf(k)
= O, so as shown in step [phase], f
(k) is determined to be in area C, and then step [
phase].

In addition, if it is determined that Δe(k)=O in step 0, then proceed to step ■ and test 8 times to see if Δe(k)=0, and Δf(k)≠ If it is 0, then Δe(k)=0, so as shown in step [phase], it is determined that e (k) is in area C, and then the process moves to step [phase].

At step 0 or 0, e (k) or f (k)
If it is determined that is in area B or C, then move to step [phase] and e L < e A LAST
Check whether < e o or not eight times, and if YES, as shown in step 0, e (k) is continuous and f
Since (k) is in area B or C, next step ■
Then, in the same manner as described above, the main detected value e(k)
and the steering angle value θ(
k).

eALAsT≦eL or eALAst in step [phase]
If it is determined that ≧e8, as shown in step [phase], e (k) is in area B or C and is discontinuous, so move to the next step [phase] and open. A steering angle correction value θ(k) is calculated based on the stopper value f (k) and the zones that have not been updated.

That is, when zone=0, θ(k) = 180+K (f(k)-eH) When zone=1, θ(k) □ 540+K(f(k)-eH) When zone=-1 is calculated and detected as θ(k)=-180+K (f(k)-e, 4) When zone=-2, θ(k)□-540+K (f(k)-eM).

Furthermore, if Δf(k) = O in step [phase], this means Δe(k) = Δf(k) = O, and as shown in step [phase], there is no change in the steering angle. Since the area is unknown, the process moves to step (2) and sets the steering angle value θ(k-1) in the previous sampling period to the steering angle value θ(k·) in the current sampling period.

In addition, in FIG. 1, FIG. 3, FIG. 5, FIG. 8, FIG. 9, and FIG. 28 is a specific example of a shaft member, the electric resistance member 40 is a specific example of a resistor, the processing in steps ①, ② and [phase] is a specific example of a slight contact state determination means, and the processing in step [phase] is a specific example of a steering wheel. A specific example of the angle calculation means is shown, and the process of step 0 is a specific example of the steering angle correction value calculation means.

In addition, although a configuration using a microcomputer is shown as a control device, instead of this, electronic circuits such as addition circuits, subtraction circuits, multiplication circuits, division circuits, command value setting circuits, comparison circuits, logic circuits, etc. It is also possible to configure a controller by combining circuits.

〔Effect of the invention〕

As explained above, in the steering angle detection device of the present invention, the first current collecting member is located at the boundary between the ring-shaped resistor and a part of the electrically unstable zone, and makes slight contact with the resistor. The micro-contact state discriminating means determines whether the first current collecting member is located at the boundary between the resistor and the electrically unstable zone and comes into slight contact with the resistor. When it is determined that the steering angle is in a state where the To prevent malfunction of steering angle calculation caused by a voltage signal detected by slight contact with a resistor located at the boundary with an electrically unstable zone, and to allow a single-turn potentiometer to function normally as a multi-turn potentiometer. This has the effect of being able to.

[Brief explanation of the drawing]

, FIG. 1 is a block diagram showing the basic configuration of the steering angle detection device of the present invention, and FIG. 2 is a schematic explanation showing the overall configuration of an electric power steering device equipped with an embodiment of the steering angle detection device of the present invention. 3 is an enlarged sectional view taken along the line mm in FIG. 2, FIG. 4 is an enlarged view of one side of the disk-shaped substrate shown in FIG. 3, and FIG. 5 is an enlarged sectional view of the disk-shaped substrate shown in FIG. 6 is an enlarged perspective view showing the wave spring shown in FIG. 3, FIGS. 7 and 8 are enlarged perspective views showing the current collecting member shown in FIG. 3, and FIG. 9 is an enlarged perspective view showing the current collecting member shown in FIG. 10 is a diagram showing the relationship between steering torque and output voltage. FIG. 11 is a diagram showing the relationship between steering angle and output voltage. FIG. 12 is a diagram showing the relationship between the steering angle area and the output voltage, and FIG. 13 is a flowchart showing the procedure of processing executed in the microcomputer included in the control device. 1a... Stub shaft, 2... Steering wheel, 4... Gear box, 5... Bearing holder, 2
8... Disc-shaped substrate, 30... Control device, 40...
Electrical resistance member, 51... Ring member, 60a...
First current collecting member, 60b...Second current collecting member, 70...
Microcomputer, 75...Interface circuit, 76...Arithmetic processing unit, 77...Storage device, C.
...Electric Fuwabelt.

Claims (1)

[Scope of Claims] A shaft member that rotates together with a steering wheel; a support member that rotatably supports the shaft member; and a support member that is fixed to one of the shaft member and the support member concentrically with the shaft member. a ring-shaped resistor having an electrical dead zone in a part thereof; one end is fixed to the other of the shaft member and the support member with a mutual phase shift, and the other end is fixed to the resistor and the electrical dead zone; first and second current collecting members that are in sliding contact with the dead zone; steering angle calculation means that calculates the steering angle of the steering wheel based on the detection signal of the first current collecting member; a steering angle correction value calculation means for calculating a correction value of the steering angle based on a detection signal of the second current collecting member when the second current collecting member is in contact with a target dead zone, based on the signal; a slight contact state determining means for determining that the first current collecting member is located at a boundary between the resistor and the electrical dead zone and is in slight contact with the previous year's resistor; When the determining means determines that the first current collecting member is located at the boundary between the resistor and the electrical dead zone and is in slight contact with the resistor, the steering angle correction value A steering angle detection device characterized in that the calculation means calculates a correction value for the steering angle based on the detection signal of the second current collecting member.