JP3132096B2 - Steering force control device for power steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power steering apparatus for controlling an assist force provided by a booster in accordance with an applied current calculated based on a running state such as a vehicle speed, a steering angle, a steering wheel torque and the like. The present invention relates to a steering force control device.

[0002]

2. Description of the Related Art For example, in a hydraulic power steering device having a steering force control device using a reaction force mechanism, as shown in FIG. 7, an electric current applied to an electromagnetic control valve of the reaction force mechanism in accordance with an increase in vehicle speed. Is reduced to increase the hydraulic pressure supplied to the reaction force mechanism, and gradually reduce the assist force to control the steering wheel torque. In this method, even if the steering wheel is turned to a large extent, the increase in the steering wheel torque at the steering wheel is small, and a good steering feeling is not always obtained. Therefore, the current applied to the electromagnetic control valve is changed to the steering shaft rotation angle (or In some cases, the steering torque is decreased by increasing the steering angle (i.e., the steering angle) and also by decreasing the assisting force in accordance with the increase of the steering shaft rotation angle and the vehicle speed. Further, with this technique, satisfactory results can be obtained with respect to the characteristics when the steering wheel is cut, but there is a problem that the steering wheel is felt heavy in the returning state of the steering wheel. Therefore, for example, as disclosed in JP-A-62-279170, When the steering angle is changing in the direction approaching the neutral position, the current applied to the electromagnetic control valve is reduced, the assist force is reduced, and the steering when returning to the steering wheel can be felt well. is there. In these techniques, the later, the more sensitive to the running condition, the better steering feeling can be obtained.

[0003] In the above-mentioned system for controlling the steering wheel torque in accordance with the steering shaft rotation angle (or the steering angle), a steering neutral position which is a reference for detecting the steering angle is required. For example, as disclosed in Japanese Patent Application Laid-Open No. 61-28811, a neutral range detector for detecting that the rotation angle position of the handle shaft is within a predetermined angle range near the steering neutral position is provided. Average value of the steering angle detected by the steering angle detector for each predetermined small traveling distance when the vehicle is within the angle range, that is, when the neutral range detector generates a neutral range signal (hereinafter, also simply referred to as SSC signal). Is calculated, and the angular position is set as a steering neutral position.

[0004]

However, in the above-described steering neutral position detecting device, it is necessary to travel a certain distance before the correct neutral position is determined. If the current applied to the electromagnetic control valve is controlled in accordance with the steering angle before the correct neutral position is determined, sensitive steering wheel torque control will be performed based on the uncertain steering angle. May cause sensation. For this reason, the current applied to the electromagnetic control valve of the reaction force mechanism is calculated according to the vehicle speed until the vehicle travels for a predetermined time or a predetermined distance from the start of travel, and thereafter, the current is calculated according to the steering angle. It is also conceivable that the applied current of the former gradually changes to the applied current of the latter in the middle. However, since the time or traveling distance until the neutral position is determined by the steering neutral position detecting device differs depending on the traveling state, if the above-mentioned predetermined time or the prescribed distance is set short, a feeling of strangeness may occur in the steering depending on the traveling state. In addition, there is a problem that if the length is set to be long, the time required for obtaining a good steering feeling increases.

According to the present invention, the timing at which the applied current applied to the control device of the power steering device is shifted from the one calculated mainly according to the vehicle speed to the one calculated according to the steering angle is changed according to the running state. The purpose is to solve each of these problems.

[0006]

For this purpose, a steering force control apparatus for a power steering apparatus according to the present invention is connected to an operating member 11 for steering a steered wheel and a steering handle 46 as shown in FIG. Handle shaft 4 for operating the operating member
7, an intensifier 12 for applying an assisting force to the operating member 11, a control device 15 for changing the assisting force applied by the intensifier 12 in accordance with the torque applied to the handle shaft 47 and the applied current, and the handle shaft 47. The steering angle detecting unit 35 for detecting the steering angle of the steered wheels by detecting the rotation angle of the steering wheel, and the rotation angle position of the handle shaft 47 near the steering neutral position and the three positions around 360 degrees to both sides of the steering neutral position. A steering sensor 30 comprising a neutral range detector 36 for detecting a position within a predetermined angular range as a center and generating a neutral range signal; and calculating the applied current in accordance with the running state of the vehicle and calculating the applied current by the controller 15 In the power steering apparatus provided with the output means 1 for outputting the rotation angle of the handle shaft 47 detected by the steering angle detection unit 35, The steering angle of the steered wheel by the steering angle detecting unit 35 which has three counters 2a to 2c corresponding to the three positions and which is sequentially performed at a predetermined interval. Counting means 2 for counting the number of detections corresponding to the three positions when the neutral range detection unit 36 generates the neutral range signal out of the number of detections in the counters 2a to 2c corresponding to the positions.
When applied to the calculated by the calculation means 1c in accordance with the difference between the largest value and the next largest difference computation the values Chico <br/> among the detected frequency counted in the counter 2a~2c A control means 3 for outputting a current from the output means 1 to the control device 15 is provided.

Further, as shown in FIG. 2, the steering force control device for a power steering device according to the present invention operates an operating member 11 for steering a steered wheel and a steering wheel 46 to operate the operating member. A handle shaft 47, an intensifier 12 for applying an assist force to the operating member 11, and a handle shaft 4
7 according to the torque applied to the motor 7 and the applied current.
2, a control device 15 for changing the assist force provided by the steering wheel 2, a steering angle detection unit 35 for detecting the rotation angle of the handle shaft 47 to detect the steering angle of the steered wheel, and the rotation angle position of the handle shaft 47 for steering. Neutral position and beyond
A steering sensor 30 including a neutral range detecting unit 36 that detects a position within a predetermined angle range around three positions around 360 degrees and generates a neutral range signal; And a power steering device comprising output means 1 for outputting the output to the control device 15. The output means 1 comprises a first calculation means 1a for calculating the applied current mainly in accordance with a vehicle speed and the steering mechanism. Second calculating means 1b for calculating the applied current according to the rotation angle of the handle shaft 47 detected by the angle detecting unit 35
And three counters 2a corresponding to the three positions.
The steering angle detecting unit 3 having the following order:
5 when the neutral range detecting unit 36 generates a neutral range signal among the number of times the steering angle of the steered wheel is detected by the control unit 5.
Counting means 2 for counting each number of detections corresponding to the position to each of the counters 2a to 2c corresponding to the position, and the largest value and the next largest value among the number of detections counted by each of the counters 2a to 2c response difference of the difference between the arithmetic Chico
Output from the output means 1 to the control device 15
The applied current may be characterized in that it comprises a control unit 3 for changing to the calculated applied current by the second calculation means 1b from the calculated applied current by the first computing means 1a.

[0008]

[Operation] After the operation of the steering force control device of the power steering device is started,
The counting means 2 counts the number of detections when the neutral range detection unit 36 generates the neutral range signal among the number of steering angle detections of the steered wheels sequentially performed by the steering angle detection unit 35 at predetermined intervals.
Each of the counters 2a to 2c corresponding to each of the three rotational angle positions of the handle shaft 47 that generates the neutral range signal is counted. The counter with the largest number of detections corresponds to the steering neutral position. The control means 3
Among the number of detections counted by each of the counters 2a to 2c, a difference between the number of detections of the largest number and the number of detections of the next largest number is sequentially calculated. The applied current calculated by 1c is output from the output means 1 to the control device 15.

The reliability of the detection result of the steering neutral position detected by the steering angle detection unit 35, that is, the reliability of the detection result of the steering angle, increases as the total number of times of detection of the steering angle increases, and the speed of the increase. Becomes larger when the vehicle is traveling near the steering neutral position. On the other hand, the difference in the number of detections also increases as the total number of detections increases, and the speed of the increase increases when the vehicle is traveling near the steering neutral position. Therefore, during the period from the start of the operation until the applied current output from the output means 1 to the control device 15 shifts from a value initially calculated based on the vehicle speed to a value calculated based on the steering angle, the steering operation is started. If the rate of increase in the reliability of the angle detection result is large, the reliability becomes short, and if the rate of increase is small, it becomes long.

Further, in the case where the output means 1 is provided with the first calculation means 1a and the second calculation means 1b, after the operation of the steering force control device of the power steering apparatus starts, the counting means 2 sets the steering angle at a predetermined interval. Of the number of times the steering angle of the steered wheels is sequentially detected by the detector 35, the number of times the neutral range detector 36 generates the neutral range signal is the number of times the steering shaft 47 generates the neutral range signal. Each of the counters 2a to 2c corresponding to the angular position counts. The counter with the largest number of detections corresponds to the steering neutral position. The control means 3 sequentially calculates the difference between the number of detections of the number of detections counted by the counters 2a to 2c and the number of detections next to the number of detections, and while the difference is small, the difference is mainly determined according to the vehicle speed. (1) The applied current calculated by the calculating means 1a is output from the output means 1 to the control device 15. If the difference becomes large, the applied current calculated by the second calculating means 1b in accordance with the rotation angle of the handle shaft 47 is calculated. The output means 1 causes the control device 15 to output.

[0011]

As described above, according to the present invention, immediately after the start of the operation, even when the reliability of the detection result of the steering angle is low, the steering does not feel strange, and a certain period elapses. After the reliability of the detection result of the steering angle is increased, the applied current calculated according to the steering angle is output to the control device, so that a good steering feeling sensitive to the running state can be obtained. Moreover, the period until the applied current output from the output means to the control device shifts to a value calculated according to the steering angle becomes shorter when the rate of increase in the reliability of the detection result of the steering neutral position is large, When the increase speed is small, the time is long, so that the time when a good steering feeling is obtained can be optimized.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. As shown in FIGS. 1, 2, and 3, the power steering device 10 includes a power cylinder (power booster) provided on an operating rod (operating member) 11 connected to a steering wheel (not shown) via a steering link mechanism. Device 12) and a control device 15. The input shaft 16 of the control device 15
The steering wheel 46 is connected to the handle shaft 47 of the steering handle 46 via the zero rotation shaft 31. An output shaft 16a provided coaxially with the input shaft 16 is connected to the operating rod 11 via a rack and pinion mechanism 13, and a servo valve 17 and a reaction force mechanism 18 are provided between the input shaft 16 and the output shaft 16a. Have been.

A supply pump 20 such as a vane pump having a built-in bypass valve 21 supplies a working fluid having a constant flow rate Q to a distribution valve 22 through a discharge passage 23. The flow dividing valve 22 distributes the working fluid having the constant flow rate Q to the servo valve passage 23a and the reaction force control passage 23b by constant flow rates Q1 and Q2, respectively. The servo valve passage 23a is connected to the power cylinder 12 via the servo valve 17, and is connected to the reaction force control passage 23.
The reaction force mechanism 18 and the electromagnetic control valve 26 are connected to b.

The servo valve 17 is a known rotary type open center type 4-port throttle switching valve, and the input shaft 16 based on the steering wheel torque applied to the steering wheel 46.
Each port 17 is operated by the twist between the shaft and the output shaft 16a.
The aperture between a and 17d is controlled. In the steering neutral state where no steering wheel torque is generated, the servo valve 17
Since both distribution ports 17c and 17d have the same low pressure, the power cylinder 12 is not operated. Steering wheel 46
Is turned to one side to generate a steering wheel torque, the servo valve 17 is deviated from the neutral state, and the pressure generated by the gear of the working fluid from the supply port 17a increases, so that one of the distribution ports 1
7c (or 17d) flows into one working chamber of the power cylinder 12 through one distribution passage 24a (or 24b) to generate an assist force, and the working fluid in the other working chamber is supplied to the other distribution passage 24b ( Or 24a) to the other distribution port 17d (or 17c) and discharge port 1
It is discharged to the reservoir 25 through 7b. The steering force acting on the operating rod 11 is increased by the assist force, and is transmitted to the steered wheels via a steering link mechanism (not shown).

The reaction force mechanism 18 includes a plunger 18b fitted in an insertion hole 18c formed in the input shaft 16,
6a, which is a well-known one having a slanted surface 18d inclined to both sides in the circumferential direction engaging with the tip of the plunger 18b as a main component. Then, the pressure of the working fluid introduced into the rear part of the plunger 18b through the port 18a is changed by the electromagnetic control valve 26 so that the input shaft 16 and the output shaft 1 are changed.
The torsion spring characteristic during 6a is changed, thereby changing the operation characteristic of the servo valve 17 for controlling the supply and discharge of the working fluid to both working chambers of the power cylinder 12. The electromagnetic control valve 26 is normally fully closed, and its opening increases with an increase in the current applied to the solenoid 26a, and finally becomes fully open.

Next, the steering sensor 30 will be described with reference to FIGS. 1, 2 and 4. FIG. The rotating shaft 3 connecting the handle shaft 47 provided with the steering handle 46 and the input shaft 16 of the control device 15
A large number of slits 35a are formed at equal angular intervals along the entire circumferential direction of the slit disk 32, which is fixed concentrically to 1, and a sector notch 36a is formed in a part of the outer periphery. The U-shaped 2 is sandwiched between the slit disks 32.
The photoelectric pickups 35b and 36b are provided on the fixed member. Long-lasting first photoelectric pickup 35b
A light emitting element and a light receiving element are provided at opposite ends of the slit 35a at positions opposite to both sides of the slit 35a. The slit 35a and the first photoelectric pickup 35b correspond to the rotation angle of the rotating shaft 31 fixed to the handle shaft 47. A steering angle detector 35 that generates a steering angle pulse signal is configured. The steering angle of the steered wheels is detected by the steering angle detector 35. A plurality of light emitting elements and light receiving elements are provided to detect the rotation direction of the rotating shaft 31.

A slit disk 32 having a fan-shaped notch 36a is formed at the tip of the shallow second photoelectric pickup 36b.
A light emitting element and a light receiving element are provided at positions sandwiching the outer peripheral portion of
A neutral range detector that generates a neutral range signal (SSC signal) when the rotary shaft 31 fixed to the handle shaft 47 is within a predetermined angle range near the steering neutral position by the sector notch 36a and the second photoelectric pickup 36b. 36 are configured. In this embodiment, the central angle α of the fan-shaped notch 36a is 60 degrees. The fan-shaped notch 36a is used not only when the handle shaft 47 is near the steering neutral position, but also when the handle shaft 47
The second photoelectric pickup 36b even in the vicinity of rotation by
As shown in FIG. 5, in addition to generating the SSC signal SSCo in a 60-degree angle range near the steering neutral position, as well as in the vicinity of a rotation of about 360 degrees left and right, each has a 60-degree angle range. Generates SSC signals SSCa and SSCb. Note that the steering angle detection unit 35 and the neutral range detection unit 36 may be integrally configured.

As shown in FIG. 3, the electronic control unit 50 includes a central processing unit (hereinafter simply referred to as CPU) 51, a read-only memory (hereinafter simply referred to as ROM) 52, and a writable memory (hereinafter simply referred to as RAM) 53. The solenoid 51a of the electromagnetic control valve 26 is connected to the CPU 51 via an interface (not shown) and a solenoid drive circuit to control the applied current. Further, the steering angle detection unit 35 and the neutral range detection unit 36 of the steering sensor 30 and the vehicle speed sensor 40 are connected to the CPU 51 via an interface (not shown). The vehicle speed sensor 40 is provided on the output shaft 43 of the transmission 42 that transmits the driving force of the engine 41 to the rear wheels, and detects the vehicle speed v.

The steering angle detector 35 detects the rotation angle θ of the handle shaft 47 every time the vehicle travels a predetermined small distance.
3, the neutral range detector 36 of the number of detections
The number of detections during signal generation is determined by the SSC signal SS
Three counters 2a to 2c counting for each of Co, SSCa, and SSCb
(See FIG. 1). The ROM 52 stores the characteristics of the reliability coefficient K and the solenoid 26a of the electromagnetic control valve 26.
The characteristics of the applied currents i1 and i2 to be output are stored. The characteristic of the reliability coefficient K is, as shown in FIG.
The difference d between the largest value and the next largest value among the number of detections counted in a to 2c is 0 when the difference d is equal to or less than d1, 1 when the difference d is greater than d1 and greater than d2, and between d1 and d2. It is a property that gradually increases. The applied current i1 has a characteristic of decreasing as the vehicle speed v increases as shown in FIG. 7, and is used when the reliability coefficient K is still small immediately after the start of operation. As shown in FIG. 8, the applied current i2 has a characteristic of decreasing with an increase in the rotation angle θ of the handle shaft 47 and the vehicle speed v, and is used when the reliability coefficient K increases after traveling to some extent. It is. Further, the ROM 52 stores a control program for executing the operation of the present embodiment described below.

Next, the operation of the above embodiment will be described with reference to the flowchart shown in FIG. When the main switch of the automobile is turned on, the electronic control unit 50 firstly operates the respective counters 2a.
2c is reset to 0, and other variables are set to 0
Alternatively, reset to a predetermined initial value. The rotation angle θ of the handle shaft 47, the SSC signal, the vehicle speed v, and the like, which change every moment in the running state of the automobile, are detected by the steering angle detection unit 35, the neutral position detection unit 36, the vehicle speed sensor 40, and the like of the steering sensor 30, respectively. Is input to a predetermined register. Then, the CPU 51 starts executing the processing operation based on the control program shown in the flowchart of FIG.

The CPU 51 first performs steps 100 to 102
In each time, it is determined whether or not the SSC signal from the neutral range detector 36 is input every time the vehicle travels a predetermined small distance (see above) from the previous sampling, and if the SSC signal is input, the steering shaft at that time is determined. 47 (or the steering angle) is read. At this time, the reference value of the rotation angle θ may be set to an appropriate temporary value (for example, a value when the main switch is turned on). When the SSC signal has not been input in step 101, the CPU 51 temporarily stops executing the control program shown in FIG.
From 00, the control program is executed. Next step 1
03, the CPU 51 determines this SSC based on the rotation angle θ.
It is determined which of the three SSC signals the signal is. If the signal is the first SSC signal, the number of detections n1 of the first counter 2a is counted up by 1 in step 104 and the second
In the case of the SSC signal, the number of detections n2 of the second counter 2b is counted up by 1 in step 105, and in the case of the third SSC signal, the number of detections n3 of the third counter 2c is counted up by 1 in step 106. The control operation proceeds to step 107. In addition, the first to third
The counters 2a to 2c may be arbitrarily made to correspond to the three SSC signals SSCo, SSCa, SSCb each time the execution of each control program is started, and the correspondence may be different at each start of operation. Alternatively, three counters 2a, 2
b and 2c are converted into three SSC signals SSCo, SSCa and SS, respectively.
You may make it correspond to Cb.

In step 107, the CPU 51 sets the largest value and the next largest value among the numbers of detections n1 to n3 counted by the counters 2a to 2c in variables N1 and N2. The difference d is calculated, and in step 109, the reliability coefficient K is calculated based on the difference d and the characteristic map of FIG. Next step 110
Where CPU 51 is

[Number 1] by i = K × i 2 + ( 1-K) × i 1 calculates the applied current i, the power cylinder 12 and outputs the applied current i to the solenoid 26a of the solenoid control valve 26 in step 11 1 To control the assist force. Then, the CPU 51 determines whether or not the reliability coefficient K has reached 1 in Step 112, and repeatedly executes the above-described control program for each predetermined small traveling distance until K reaches 1; The applied current i is output to the solenoid 26a. When the reliability coefficient K reaches 1, the CPU 51 ends the execution of the control program according to the flowchart of FIG.

In parallel with the execution of the control program shown in the flowchart of FIG. 9, the CPU 51 uses the control program (not shown) to apply the applied currents i1 and i2 used in step 110.
Is repeatedly calculated for each predetermined small traveling distance. Applied current i1
And i2 are the characteristic maps of FIGS. 7 and 8 according to the rotation angle θ of the handle shaft 47 detected by the steering angle detection unit 35 based on the steering neutral position calculated separately and the vehicle speed v detected by the vehicle speed sensor 40. It is calculated by The steering neutral position serving as a reference for detecting the rotation angle θ of the handle shaft 47 is obtained by separately calculating the average value of the rotation angle θ detected by the steering angle detection unit 35 when the SSC signal SSCo is generated by a control program (not shown). It is obtained by calculating. After the execution of the control program according to the flowchart of FIG. 9, the CPU 51 repeatedly applies the applied current i1 calculated for each predetermined small traveling distance to the solenoid 26a of the electromagnetic control valve 26.
Output to Instead of executing the control program of FIG. 9 every predetermined short traveling distance as in this embodiment, the control program may be executed every predetermined short time.

In the operation described above, the counter that counts the largest value among the numbers of detections n1 to n3 corresponds to the steering neutral position.
The number of times the steering angle is detected by the steering angle detector 35 when the signal SSCo is generated is counted. The reliability of the detection result of the steering neutral position detected by the steering angle detection unit 35, that is, the reliability of the detection result of the steering angle, increases as the total number of detections increases, and the vehicle may travel near the steering neutral position. Obviously, the larger the number, the faster the increase. On the other hand, when the vehicle frequently travels near the steering neutral position, the number of times the steering angle is detected while the SSC signal is being generated is mainly counted by the counter (for example, the first counter 2a) corresponding to the steering neutral position. The difference between the number of detections of that counter and the number of detections of other counters increases quickly. That is, the difference d between the largest value (the value when the SSC signal SSCo is generated) and the next largest value among the detection counts counted by the counters 2a to 2c is the reliability of the steering angle detection result. They are in a proportional relationship. Therefore, as in the above embodiment, the electromagnetic control valve 26
The applied current i to the solenoid 26a of the values i1 computed according to the vehicle speed v when the difference d is d 1 below, this difference d is
If d 2 or more, the rotation angle θ of the handle shaft 47 and the vehicle speed v
A value i2 calculated in accordance with, between d 1 and d 2 applied current i
Is gradually changed from i1 to i2 as the difference d increases, so that a feeling of strangeness of steering does not occur immediately after the start of operation, and after a certain period of time, a good steering feeling that responds sensitively according to the steering angle. Can be obtained, and the transition timing between these two characteristics can be set to the optimal timing based on the reliability of the detection result of the steering angle that differs depending on the traveling state.

In the above embodiment, the case where a reaction force type steering force control device is used has been described. However, the present invention bypasses between the two distribution ports of the servo valve or between the discharge side and the suction side of the pump. The present invention can be applied to a system using a bypass-type steering force control device provided with an electromagnetic control valve.
The present invention can also be implemented in an electric power steering device. Further, in the present embodiment, the control in the case of low reliability is performed based on the vehicle speed. However, the present invention is not limited to this. The control may be performed based on the engine speed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a steering force control device for a power steering device according to a first invention.

FIG. 2 is a diagram showing an overall configuration of a steering force control device for a power steering device according to a second invention.

FIG. 3 is an overall view of an embodiment of a steering force control device for a power steering device according to the present invention.

FIG. 4 is a cross-sectional view showing a main part of the steering sensor.

FIG. 5 is a diagram showing a relationship between a rotation angle of a handle shaft and an SSC signal.

FIG. 6 is a characteristic map of a reliability coefficient.

FIG. 7 is a characteristic map of an applied current used when the reliability coefficient is low.

FIG. 8 is a characteristic map of an applied current used when the reliability coefficient is high.

FIG. 9 is a diagram showing a flowchart of a control program.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Output means, 1a ... 1st arithmetic means, 1b ... 2nd arithmetic means, 1c ... arithmetic means, 2 ... counting means, 2a ... 1st counter, 2b ... 2nd counter, 2c ... 3rd counter, 3 ... control Means, 11: operating member (operating rod), 12: booster (power cylinder), 15: control device, 30: steering sensor, 35: steering angle detector, 36: neutral range detector, 46
... steering wheel, 47 ... handle shaft.

Continuation of the front page (56) References JP-A-61-211167 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B62D 6/00-6/06

Claims (2)

(57) [Claims] 1. An operating member for steering a steered wheel, a handle shaft connected to a steering handle to operate the operating member, a booster for applying an assist force to the operating member, and a torque and a torque applied to the handle shaft. A control device that changes an assist force provided by the booster in accordance with an applied current;
A steering angle detector for detecting a steering angle of the steering wheel by detecting a rotation angle of the handle shaft, and three positions near a neutral position of the handle shaft and a position rotated 360 degrees to both sides from the steering neutral position; A steering sensor consisting of a neutral range detector that detects a neutral angle range and detects a neutral range signal, and calculates the applied current according to the running state of the vehicle and outputs it to the controller. A power steering device comprising an output unit that performs an operation of the applied current in accordance with a rotation angle of the handle shaft detected by the steering angle detection unit; The neutral range detecting unit generates a neutral range signal among the number of times the steering angle detecting unit detects the steering angle of the steered wheel, which has three counters corresponding to positions and is sequentially performed at predetermined intervals. Counting means for counting the respective counters corresponding to the respective detection times corresponding to Kino the 3 position to that position, the difference between the largest value and the next larger value of the detection frequency counted in the respective counter steering force control device for a power steering apparatus according to claim the computed applied current by the calculation means according to a difference between arithmetic Sico from said output means further comprising a control means for outputting to the control unit. 2. An operating member for steering a steered wheel, a handle shaft connected to a steering wheel to operate the operating member, a booster for applying an assist force to the operating member, and a torque and a torque applied to the handle shaft. A control device that changes an assist force provided by the booster in accordance with an applied current;
A steering angle detector for detecting a steering angle of the steering wheel by detecting a rotation angle of the handle shaft, and three positions near a neutral position of the handle shaft and a position rotated 360 degrees to both sides from the steering neutral position; A steering sensor consisting of a neutral range detector that detects a neutral angle range and detects a neutral range signal, and calculates the applied current according to the running state of the vehicle and outputs it to the controller. A power steering device comprising an output unit that calculates the applied current mainly according to a vehicle speed.
A second calculating means for calculating the applied current in accordance with a rotation angle of the steering wheel shaft detected by a calculating means and the steering angle detecting section;
Calculating means for detecting the steering angle of the steered wheel by the steering angle detecting unit, which has three counters corresponding to the three positions and which is sequentially performed at a predetermined interval; Counting means for counting each number of detections corresponding to the three positions when a signal is generated in each counter corresponding to the position; and the largest value among the number of detections counted in each counter and the next Large value difference
Said control device from said output means in response to the difference computation Sico the
Control means for changing the applied current to be output to the applied current calculated by the first calculating means from the applied current calculated by the first calculating means to the applied current calculated by the second calculating means. apparatus.