JPS63241403A - Controller for load for automobile - Google Patents

Abstract

PURPOSE:To control a load for an automobile with high accuracy by eliminating the error of a position signal indicating the rotational position of a steering wheel obtained by an absolute type encoder. CONSTITUTION:An encoder 17 outputs a voltage signal V1 which varies from zero to Vc every time the steering wheel (SW) is turned by nearly one rotation and an encoder 19 outputs a voltage signal V2 which varies from zero to Vc according to nearly 3.5 rotations of the SW 1. Then the signal V1 within a rotational angle range of + or -45 deg. from the neutral point of the SW 1 or the signal V2 when the rotational angle exceeds + or -45 deg. is outputted from an output terminal 23. Here, a voltage signal Vn is the composite signal of the signals V1 and V2 and a control circuit 30 computes DELTAV=Vn-Vc/2 at the neutral position of the SW 1 to store the DELTAV in an EPROM 27 as an error correcting signal and then generates a correcting signal by subtracting the signal DELTAV from the signal Vn, thereby controlling the automobile load 29 according to it.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a device for controlling an automobile load according to the rotational state of a steering wheel, and in particular, to a device for controlling an automotive load according to the rotational state of a steering wheel. The present invention relates to an automotive load control device in which a signal indicating a signal is detected by an absolute encoder.

(Prior Art) In recent years, in automobiles, in order to obtain better steering stability or a more comfortable ride, damping force control of the suspension, according to the rotation angle (steering angle) of the steering wheel and the running speed, It has been considered to control the shift position of an automatic transmission, control the steering of the rear wheels (control of a so-called four-wheel steering system), and the like.

For the above-described control, a rotation detection device is required to detect the rotation angle (and, if necessary, the rotation direction) of the steering wheel. Conventionally, such rotation detection devices have been used to detect specific positions of the steering wheel (
For example, it has been considered to use an absolute encoder that generates a position signal indicating the absolute amount of rotation from a neutral position. That is, as this type of encoder, for example, one is provided in which a brush is provided on a rotating member that follows the rotation of a steering wheel, and a resistor is provided that generates a resistance value output according to the sliding contact position of this brush. This product outputs a specified resistance value when the steering wheel is in the neutral position (output indicating the origin of the absolute encoder).
In recent years, as the automobile market has matured, it has become necessary to control the automotive load with high precision. When controlling an automotive load using the output of an absolute encoder like the one above,
It is necessary to precisely match the output indicating the origin and the neutral position of the steering wheel. However,
When an absolute type encoder is mounted, dimensional errors of the parts, assembly errors, and errors due to variations in accuracy when assembling to the steering wheel side are small.
There is a risk that the actual neutral position of the steering wheel and the neutral position indicated by the origin output of the absolute encoder may deviate. Therefore, in such a case, the error in the position signal from the absolute encoder becomes large, and the control accuracy of the automobile load deteriorates.

The present invention has been made in view of the above circumstances, and its purpose is to improve position signals from absolute encoders used to control automotive loads, that is, position signals indicating the amount of rotation of a steering wheel from a specific position. It is an object of the present invention to provide a control device for an automobile load that can easily and reliably eliminate errors, thereby achieving effects such as controlling the automobile load with high precision.

[Structure of the Invention] (Means for Solving the Problems) An automotive load control device according to the present invention includes an absolute encoder that is assembled to generate a position signal indicating the amount of rotation of a steering wheel from a specific position. ,
a setting means for outputting a storage command signal while the steering wheel is at the specific position, and an error correction signal corresponding to the position signal from the absolute encoder at the time when the storage command signal is output. In addition to providing storage means for storing the information, a control means is provided for controlling the negative 6f for the automobile based on a signal obtained by correcting the position signal from the absolute encoder using the error correction signal.

(Function) The device signal composed of the absolute type encoder indicates the rotation of the steering wheel from a specific position, but in reality, it is due to the assembly error and assembly error of the parts. etc., the amount of rotation of the steering wheel may deviate from the actual amount. On the other hand, the position signal at the time when the storage command signal is output from the setting means accurately indicates that the steering wheel is at a specific position. Therefore, the signal obtained by correcting the device signal composed of the absolute encoder according to the rotation of the steering wheel by the error correction signal corresponding to the position signal at the above-mentioned time point is the actual signal of the steering wheel. This corresponds accurately to the amount of rotation of the motor vehicle, and the automobile load can be controlled with high precision based on such a corrected signal.

(Example) Hereinafter, a first example of the present invention will be described with reference to FIGS. 1 to 7.

In FIG. 3, 1 is a steering wheel connected to a steering shaft (not shown), 2 is a plastic annular base fixed to a suitable stationary part (for example, a steering column) while surrounding the steering shaft; It is formed into a double cylindrical shape with a side wall 2a and an inner peripheral side wall 2b. Reference numeral 3 denotes a cylindrical coupling body made of plastic, for example, which is rotatably arranged between the periphery of the steering shaft and the inner periphery of the base 2. This is a cylindrical coupling body made of plastic, for example. When the steering wheel 1 is engaged with the steering wheel 1, the steering wheel 1 rotates integrally with the steering wheel 1.

Reference numeral 4 denotes a cylindrical rotor rotatably disposed on the lower surface side of the base 2 surrounding the connecting body 3, and an engagement groove 4a on the inner circumferential surface of the rotor 4 is connected to an engaging groove protruding from the outer circumferential surface of the connecting body 3. The rotor 4 is engaged with the mating protrusion 3b, so that the rotor 4 is configured to rotate together with the coupling body 3 and, in turn, with the steering wheel 1.

Further, the outer peripheral surface of the rotor 4 is provided with a sun tooth +6 that forms a part of a gear mechanism 5 consisting of a planetary southeast mechanism.

In addition to the sun gear 6, the gear mechanism 5 includes an internal gear 7 formed on the inner periphery of the outer peripheral side wall 2a of the base 2, and an internal gear 7 interposed between the sun gear 6 and the internal gear 7. Play J1 consisting of stepped gears! It has a gear 8. Further, reference numeral 9 denotes a deceleration rotating body which is driven by the gear mechanism 5, and this is made of an annular plate and is arranged within the outer peripheral side wall 2a of the base 2 so as to rotate around the rotor 4. And this deceleration rotating body 9
The planetary gear 8 is rotatably supported on a support shaft 9a that is integrally provided. Here, the small-diameter pinion 8a located at the upper stage of the planetary gear 8 is meshed with the internal gear 7, and the large-diameter pinion 8b located at the lower stage is engaged with the sun gear 6.
In the gear mechanism 5 configured in this way, the rotation of the steering wheel 1 is controlled by the planetary gear 8.
The revolving force is then transmitted to the deceleration rotating body 9. The reduction ratio at this time is set to about 1/4. In this case, in a typical automobile, the movable range of the steering wheel 1 (so-called lock-to-lock range) is set to about 3.5 rotations, and therefore the rotation range of the deceleration rotor 9 is 1 rotation. It will be suppressed to less than a minute.

Reference numeral 10 denotes a composite substrate fixed to the lower surface of the base 2. On the lower surface of this composite substrate, endless annular electrode patterns 11 and 12 arranged concentrically are formed by printing, as shown in FIG. , an annular first resistance pattern 13 with ends, which is a first resistor located inside the electrode pattern 11, and a second annular resistance pattern with ends, which is a second resistor located outside the electrode pattern 12. Patterns 14 are formed by printing (in FIG. 4, each pattern 1
1 to 14 are marked with a diagonal line). Further, the composite substrate 10 is provided with terminals lla and 12a connected to the electrode patterns 11 and 12, respectively, and a first
Terminal 13 connected to both ends of resistor pattern 13 of
Terminals 14a and 14b connected to both ends of resistor pattern a and 13b as well as second resistor pattern 14 are provided, respectively. In addition, in FIG. 4, an insulating coating 15 is applied to a portion indicated by a two-dot chain line.

Now, the rotor 4 is provided with an arm 4b,
This arm 4b is provided with a first brush 16 that bridges between the electrode pattern 11 and the ml resistance pattern 13. And this brush 16. Electrode pattern 11
．． The first resistor pattern 13 and the rotor 4 constitute a first absolute encoder 17 . At this time, the first brush 16 is provided so as to be movable and adjustable in the circumferential direction of the rotor 4, and when the steering wheel 1 is in a specific neutral position, the middle point of the first resistance pattern 13 ( It is adjusted so as to bridge between the point C1 in FIG. 4 and the electrode pattern 11.

Therefore, when the steering wheel 1 is in the neutral position, the resistance value between the terminals lla and 13a and the resistance value between the terminals lla and 13b are equal, but as the steering wheel 1 is rotated to the right or left, Each of the above resistance values changes. In particular, terminal 11a.

13 b + i3], the resistance increases linearly as the steering wheel 1 is rotated to the right (rotation in the direction of arrow A in Fig. 4), and increases linearly as the steering wheel 1 is rotated to the left. It will decrease linearly according to In this case, a constant voltage Vc (terminal 13b is at ground potential) is applied between the terminals 13a and 13b, and therefore a voltage is applied between the terminals lla and 13b according to the rotation of the steering wheel 1. A first voltage signal vl, which is a position signal that changes as shown by a solid line in FIG. 5, is output. In other words, the first voltage signal V1 is
V from zero every time the steering wheel 1 is rotated approximately once.
By this, the rotation angle and direction of rotation h'' of the steering wheel 1 can be detected.

On the other hand, a second brush 18 is provided on the deceleration rotating body 9 to bridge between the electrode pattern 12 and the second resistance pattern 14.
is provided, and this brush 18, electrode pattern 12
．． A second absolute encoder 19 is configured by the second resistance pattern 14 and the deceleration rotating body 9. At this time, the second brush 18 is provided so as to be able to move 21 sections in the circumferential direction of the deceleration rotary body 9, and when the steering wheel 1 is in the neutral position, the second brush 18 is located at the midpoint of the second resistance pattern 14 ( 02 in FIG. 4) and the electrode pattern 12.

Therefore, when the steering wheel 1 is in the neutral position, the resistance value between the terminals 12a and 14a and the resistance value between the terminals 12a and 14b are equal, but as the steering wheel 1 is rotated to the right or left, 1) Each resistance value changes. In particular, terminal 12a.

When focusing on the resistance value between 14b, the resistance value increases linearly as the steering wheel 1 is rotated to the right, and decreases linearly as the steering wheel 1 is rotated to the left. Also in this case, the terminals 14a and 14b
A constant voltage Vc (terminal 14b is at ground potential) is applied between the terminals 12a and 12a.
, 14b outputs a second voltage signal v2, which is a position signal that changes as shown by the two-dot chain line in FIG. 5 in accordance with the rotation of the steering wheel 1. In other words, the second voltage signal v2 changes from zero to Vc as the steering wheel 1 is rotated approximately 3.5 degrees.
This makes it possible to detect the rotation angle and rotation Jj direction of the steering wheel 1 from the neutral position.

FIG. 6 schematically shows the configuration of a signal processing circuit 20 for synthesizing the first and second voltage signals v1 and v2. In this FIG. 6, 21 and 22 are analog switches that become conductive only when a high level signal is received at the gate terminal, and one analog switch 21 is the first
The other analog switch 22 is interposed between the second absolute encoder 19 and the output terminal 23. 24 is a discrimination circuit that receives the second voltage signal 2 from the second absolute encoder 19, and this determines whether the rotation angle of the steering wheel 1 from the neutral position indicated by the bipedal voltage signal V2 is ±45''. It is configured to output a discrimination signal Sd (high level signal) only when it is within the range.
-1- The discrimination signal Sd is directly applied to the gate terminal of the analog switch 21, and is also applied directly to the gate terminal of the analog switch 21.
The signal is applied to the gate terminal of No. 2 through an inverter 25, and is applied to an external circuit through an auxiliary output terminal 26.

As a result of this configuration, when the rotation angle of the steering wheel 1 from the neutral position is within ±45°, the analog switch 21 becomes conductive and the first voltage signal 1 from the first absolute encoder 17 is output. is output through the output terminal 23. Also, at this time,
A discrimination signal Sd is output from the auxiliary output terminal 26. When the rotation angle of the steering wheel 1 from the neutral position exceeds ±45°, the analog switch 22 becomes conductive and the second voltage signal v1 from the second absolute-1 type encoder 19 is output to the output terminal. 23. That is, as the steering wheel 1 is rotated, the output terminal 23 outputs a composite voltage, which is a position signal obtained by combining the first and second voltage signals 1 and v2, as shown in FIG. 7(a). The signal Vn is output, and the auxiliary output terminal 26 outputs the discrimination signal Sd as shown in FIG.
is output. Note that the composite voltage signal V from the output terminal 23
n is used for vehicle load control (suspension control, automatic transmission control, etc.) as described later, and the discrimination signal Sd from the auxiliary output terminal 26 indicates that the composite voltage signal Vn is It is used to determine which of the voltage signals 1 and v2 corresponds to the voltage signal 1 and the second voltage signal v2.

Now, FIG. 1 shows an outline of a control system for an automobile load using a composite voltage signal Vn and a discrimination signal Sd. In this FIG. 1, 27 is an EPR which is a storage means.
OM, 28 is a setting means comprising a switch element such as a wire cut switch, and this is configured to output a memory command signal Sa when the signal wire in the wire cut switch is cut by a tool or the like. . At this time, the cutting of the signal wire as shown in ";" is carried out, for example, on an automobile production line when the steering wheel 1 is in the neutral position (straight-ahead position). Reference numeral 29 denotes an automobile load, such as an electromagnetic solenoid for changing the damping force of a suspension or an electromagnetic solenoid for changing the shift position of an automatic transmission. Reference numeral 30 denotes a control circuit as a control means, which is configured using a microcomputer, and is configured to control the composite voltage signal Vn from the signal processing circuit 20, the discrimination signal Sd, the storage contents of the EPROM 27, the storage command signal Sa from the setting means 28, and The vehicle load 29 is controlled based on a control program stored in advance.

Therefore, in the following, the control circuit 3 described in 2.
The contents of the portions of the control program 0 that are related to the gist of the present invention will be explained with reference to FIG.

That is, the control circuit 30 first receives the storage command signal S.
When a is input, in other words, when the steering wheel 1 is in the neutral position, the composite voltage signal Vn input at that time is read and temporarily stored (steps a, b). Then, ΔV m V n −
V c /'l is calculated, and the calculation result ΔV is stored in the EPROM 27 as an error correction signal (steps c and d).

Here, Vc/2 is determined from FIGS. 5 and 7.

Since it corresponds to the neutral position of the steering wheel 1 indicated by the composite voltage signal Vn, the error correction IE signal Δ■ corresponds to the actual neutral position of the steering wheel 1 and the first and the neutral position detected by the second absolute encoders 17 and 19. In other words, the composite voltage signal Vn indicates the amount of rotation of the steering wheel from the neutral position, but in reality it is due to dimensional errors, assembly errors, and assembly errors of components in the first and second absolute encoders 17 and 19. Due to variations in accuracy, the characteristic curve may deviate from the originally required characteristic curve as shown by the broken line in FIG. 7, and the voltage value shown by ΔV in FIG. 7 appears as an error.

The control circuit 30 includes the EPROM 27 as described above.
After storing the error correction signal Δ■ for , the composite voltage signal Vn is read and the composite voltage signal, V
A correction signal v'n is obtained by subtracting the error correction signal ΔV from n (steps e and f), and a control routine for the vehicle load 29 is executed based on the +fi positive signal V'n. After this, a loop is formed that sequentially executes steps e and f and the control routine g.

In the configuration of the present embodiment described above, the error correction signal ΔV stored in the EPROM 27 is calculated based on the difference between the actual neutral position of the steering wheel 1 and the neutral position indicated by the composite voltage signal Vn that is input manually. Since it corresponds to the error, the correction signal V'n obtained by subtracting this error correction signal ΔV from the composite voltage signal Vn is the one in which the error described in is eliminated and the actual value of the steering wheel 1 is It corresponds accurately to the amount of rotation. Therefore, the control accuracy of the automobile load 29 by the control circuit 30 becomes extremely high. Further, the second voltage signal v2 from the second absolute encoder 19 changes linearly even when the steering wheel 1 is rotated multiple times, and therefore, the second voltage signal v2 Based on this, the rotation angle and rotation direction of the steering wheel 1 from the neutral position can be detected in real time over a wide range. However, since the second voltage signal v2 is obtained by decelerating the rotation of the steering wheel 1, it has a weak point in that its resolution, that is, its accuracy is low. On the other hand, the first voltage signal v1 output from the first absolute type encoder 17 is
Since the information is obtained from the rotor 4 that rotates integrally with the rotor 4, there is a drawback that the neutral position of the steering wheel 1 cannot be specified, but the information on the rotation angle and rotation direction of the steering wheel 1 obtained based on this information is becomes high.

Therefore, ':51 and the second voltage signal V1. The composite voltage signal Vn, which is synthesized by the signal processing circuit 20 so as to complement each other, is a composite voltage signal Vn that indicates the rotation angle and rotation direction of the steering wheel 1 from the neutral position over a wide range with high accuracy and in real time. becomes. In this case, in this embodiment, the rotation range of the steering wheel 1, which requires particularly high precision, is ± from the neutral position.
Since the second voltage signal v2 is used in the range of 45 degrees), the suspension of the automobile can be controlled.

Automatic transmission control etc. can be performed in detail.

In addition, in the second embodiment, ΔV(-
Vn-Vc/2) is stored in the EPROM 27, but the composite voltage signal Vn at the time when the storage command signal Sa is output is directly used as an error correction signal in the EPRO.
It may be stored in M27, and in this case, the control circuit 30 may calculate the error based on the stored contents each time the composite voltage signal Vn is read. Also,
In the above embodiment, the EPROM 27 is used as a storage means, but other storage means such as a RAM with a backup power supply may be used instead.

FIG. 8 shows a second embodiment of the present invention, and hereinafter only the differences from the first embodiment will be explained. That is, 31 is a setting means, which has a function of detecting the distance traveled by the automobile 7, and is configured to output a storage command signal S'a when the distance traveled reaches a certain value. 32 is an average value calculation circuit, which calculates the average value of the composite voltage signal Vn in real time, and
It is configured to output the calculation result as an average position signal Vna. The control circuit 30 has a function of storing the average position signal Vna in the EPROM 27 when the storage command signal S'a is applied. At this time, since the average position signal Vna obtained when the automatic width travels a certain distance is approximate to the composite voltage signal Vn when the steering wheel 1 is in the neutral position, such average position signal Vna is composited. It can be used to correct errors in the voltage signal Vn. Therefore, in this embodiment as well, the same effects as in the first embodiment can be achieved.

In this second embodiment, the function of the average value calculation circuit 32 may be obtained by a control program of the control circuit 30.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings; for example, it is not necessary to provide two types of absolute encoders, and the present invention can be implemented with various modifications without departing from the gist thereof. be able to.

[Effects of the Invention] As is clear from the above description, according to the present invention, a position signal indicating the rotational position of the steering wheel is obtained by an absolute encoder, and the automobile load is controlled using the position signal. In this apparatus, the error in the position signal can be easily and reliably eliminated, and the automatic heavy load control can be performed with high precision, which is an excellent effect.

[Brief explanation of drawings]

1 to 7 show a first embodiment of the present invention, FIG. 1 is a block diagram showing the outline of the electrical configuration, and FIG. 2 shows the main part of the control content by the control means. Flowchart, FIG. 3 is a vertical cross-sectional view of the absolute encoder and related parts, FIG. 4 is a front view showing the main parts in FIG. 3, FIG. 5 is an output characteristic diagram of the absolute encoder, and FIG. The figure is an electrical configuration diagram showing an outline of the signal processing circuit, and FIG. 7 is an output characteristic diagram of the signal processing circuit. Further, FIG. 8 is a diagram corresponding to FIG. 1 of the second embodiment of the present invention. In the figure, 1 is a steering wheel, 2 is a base, 4 is a rotor, 5 is a gear mechanism, 6 is a sun gear, 7 is an internal gear, 8 is a planetary gear, 9 is a reduction rotor, 10 is a composite substrate,
11.12 is an electrode pattern, 13 is a first resistance pattern, 14 is a second resistance pattern, 16 is a first brush, 1
7 is a first absolute encoder, 18 is a second brush, 19 is a second absolute encoder, 2
0 is a λ processing circuit, 27 is an EPROM (storage means),
28 is a set means, 29 is an automobile load, 30 is a control circuit (control means), 31 is a set means, and 32 is an average value calculation circuit. Applicant Toyota Motor Corporation Tokai Rika Electric Manufacturing Co., Ltd. Figure 2 Figure 3 Voltage Figure 5 Figure 7

Claims (1)

[Scope of Claims] 1. In a device configured to control an automobile load according to the rotational state of a steering wheel, a position signal indicating the amount of rotation from a specific position is generated according to the rotation of the steering wheel. an absolute type encoder assembled in such a manner, a setting means for outputting a storage command signal with the steering wheel at the specific position, and a position signal from the absolute encoder at the time when the storage command signal is output. and a control means for controlling the automotive load based on a signal obtained by correcting the position signal from the absolute encoder using the error correction signal. An automotive load control device characterized by: 2. The automobile load control device according to claim 1, wherein the specific position corresponding to the absolute encoder is a neutral position of the steering wheel. 3. The automobile load control device according to claim 1, wherein the setting means includes a switch element that generates a storage command signal in response to a manual operation. 4. The setting means is configured to generate a storage command signal when the vehicle has traveled a certain distance or more, and the storage means is configured to store the average value of the position signals from the absolute encoder. An automobile load control device according to claim 1, characterized in that: