JP2008285030A - Vehicular control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit a rack end feeling suitable for a driver, in a constitution wherein a steering wheel and a steering gear are mechanically separated. <P>SOLUTION: When the steering gear reaches a rack end, a signal is inputted in a rack end signal detecting means 38. The rack end signal detecting means 38 actuates a rack end reaction force signal generating means 37, and inputs a command value increasing an electric current value in a driving signal producing means 36. The driving signal producing means 36 gives a driving force to a steering shaft 3 connected with the steering wheel 2 by the driving motor 12 according to a difference between a steering angle and a turning angle, thereby generating a steering reaction force. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle control device.

  A steer-by-wire vehicle control device has been developed in which a steering wheel and a steering gear for steering a steering wheel are mechanically separated. In this vehicle control device, a sensor for detecting the rotation of the steering wheel is provided, the steering angle of the steering wheel is detected by the sensor, and the steering angle corresponding to this is calculated by the control device. Further, the steering gear is driven so that the steering wheel angle matches the steering angle.

In this type of vehicle control device, a motor is provided so as to apply a reaction force to the steering wheel. When applying the reaction force, the rotation angle of the steering wheel and the vehicle speed are detected, and the target reaction force torque is calculated according to these. Torque corresponding to the target reaction torque is applied to the steering wheel. On the steered wheel side, the motor is steered by servo control (see, for example, Patent Document 1).
JP 2004-218553 A

However, it is difficult to achieve a feeling of hitting the rack end (hereinafter referred to as a rack end feeling) simply by applying a reaction force to the steering wheel by rotating the motor. Depending on the driver, the steering wheel may be turned more than necessary. There was a case. In such a case, the motor that drives the steering gear may be locked.
The present invention has been made in view of such circumstances, and it is a main object of the present invention to transmit an appropriate rack end feeling to the driver.

The invention according to claim 1 of the present invention that solves the above-described problems includes a steering shaft that is rotatably supported on a vehicle body of a vehicle, a steering wheel that is attached to the steering shaft and rotates together with the steering shaft, and the steering A first encoder that detects the rotation of the shaft, a first count means that counts the pulse signal detected by the first encoder, and generates a first count signal; and the first count means that outputs the first count signal. A steering angle calculating means for converting the first count signal into a signal indicating the amount of rotation of the steering wheel and outputting it as a steering angle signal, a steering wheel supported so as to be steerable on the vehicle body, a motor, A driver having a rack and pinion mechanism and changing the steering angle of the steering wheel with respect to the vehicle body of the vehicle And detecting a change in the steering angle of the steering wheel, counting a detection signal supplied from an encoder that generates a detection signal in accordance with the change in the steering angle of the steering wheel, and calculating a second count signal The second count means to output and the second count signal supplied from the second count means are converted into a signal indicating the amount of change in the steering angle of the steering wheel and output as a steering angle signal. Steering angle calculation means, angle difference signal calculation means for generating an angle difference signal corresponding to the difference between the steering angle signal calculated by the steering angle calculation means and the steering angle signal calculated by the steering angle calculation means, An angle difference signal is supplied from the angle difference signal calculating means, a drive signal is generated based on the angle difference signal, and a drive signal is generated so that the steering angle signal matches the steering angle signal. And the drive signal A drive circuit for supplying current to the drive motor upon receipt of power and a current supplied to the drive motor upon receiving a rack end signal indicating that the rack of the rack and pinion mechanism has reached the rack end. The vehicle control device includes a rack end reaction force signal generation unit that generates a reaction force signal that is increased from a value determined by the difference signal.
This vehicle control device increases the current supplied to the drive motor when it is determined that the rack end has been reached, and generates a large reaction force on the steering shaft. Increased reaction force gives the driver a rack-end feeling.

According to a second aspect of the present invention, in the vehicle control device according to the first aspect, a current sensor that detects a current supplied to the steering motor, and a steering angle corresponding to a rack end of the steering motor. Rack end determination means for generating a rack end signal when rotation is not detected and the current supplied to the steering motor exceeds a predetermined value.
When it is determined that the rack end has been reached, if it is determined only by the current value, it may be erroneously determined when the steering is in progress and the angle difference with respect to the target is large. In addition, the encoder output alone may cause an erroneous determination when the steering wheel is stopped. The rack end determination means increases the rack end determination accuracy by monitoring the steering angle, current value, and encoder output.

The invention according to claim 3 is the vehicle control device according to claim 2, wherein the steering angle of the steering wheel does not change and the current supplied to the steering motor exceeds a predetermined value. And a current reduction signal generating circuit for reducing a current supplied to the steering motor.
The vehicle control device reduces the current supplied to the steering motor and prevents the steering motor from being locked when the current value increases while the steering angle does not change.

  According to the present invention, when the rack end is reached during steering, the reaction force applied to the rotating shaft is increased, so that the driver can easily recognize that the rack end has been reached from the change in the reaction force. Become. Steering beyond the rack end is prevented, and excessive current flow when the motor is locked can be prevented.

  As shown in FIGS. 1 and 2, the vehicle control apparatus 1 operates a steering shaft 3 to which a steering wheel 2 as input means operated by a driver is attached, and a steered wheel (hereinafter referred to as a tire) 4. The steering gear 5 to be directed is not mechanically connected, and is electrically connected via the first control device 6 on the steering shaft 3 side and the second control device 7 of the steering gear 5.

  The steering shaft 3 is rotatably supported by a housing 11 fixed to the vehicle body. The housing 11 accommodates a drive motor 12 in which a reduction mechanism is attached to the electric motor, and is coupled to the steering shaft 3 so that the power of the drive motor 12 can be transmitted. Furthermore, a first encoder 13 that outputs a pulse signal according to the rotation of the steering wheel 2 and a third encoder 14 that detects a neutral point of the steering angle of the steering wheel 2 are attached to the housing 11. . The drive motor 12 is connected to the first control device 6 via the drive circuit 15. The drive circuit 15 includes a switching element and the like, and is configured to supply a current from a power source (not shown) to the drive motor 12.

  The first encoder 13 is an optical rotary encoder. The rotary encoder has a disk (not shown) that rotates together with the steering wheel 2, and two rows of patterns are formed on the disk. Each pattern is composed of, for example, slits having substantially the same width formed at equal intervals in the circumferential direction, and the arrangement of the slits in the other pattern is set to 1/4 of the slit width in the circumferential direction with respect to the arrangement of the slits in one pattern. It is arranged just shifted. Therefore, if the light emitting element and the light receiving element are arranged with the disc interposed therebetween, a signal in which the pulse generation timing is shifted by a quarter period corresponding to each pattern is obtained. An example of such a pulse signal is shown in FIG. Hereinafter, a first pulse signal generated by one pattern is referred to as an A-phase rotation detection signal Aw, and a second pulse train signal generated by the other pattern is referred to as a B-phase rotation detection signal Bw.

  The second encoder 14 is used as a center position detection sensor that detects a position at which the steering angle is reset. For example, a sensor is used that provides a marker on a disc that has been decelerated to rotate once when the steering wheel 2 is rotated within a steerable range, and that outputs a pulse signal when this marker is detected. The marker is provided corresponding to the rotational position of the steering wheel 2 when the tire 4 faces in the straight traveling direction. Since the vehicle is configured such that the tire 4 can be steered by the same amount on the right side and the left side with respect to the straight traveling direction, the rotational position of the steering wheel 2 at this time corresponds to a neutral point in the steerable region. To do. Accordingly, when the driver rotates the steering wheel 2, one neutral point position signal Cw (see FIG. 3) is output as the initial position signal each time the neutral point is reached. The neutral point position signal Cw is a pulse signal having a time width longer than ½ of each cycle of the rotation detection signals Aw and Bw and shorter than each cycle of the rotation detection signals Aw and Bw.

The first control device 6 includes, as first counting means, an up / down determination circuit 21 to which the rotation detection signals Aw and Bw are input, an edge detection means 52A to which the rotation detection signal Aw is input, and rotation detection. An edge detection unit 52B to which the signal Bw is input and an up / down counter 24 as a first counter are provided.
The up / down counter 24 is connected to the outputs of the edge detection means 22A and 22B via the OR circuit 25, and to the output of the up / down determination circuit 21 and the output of the reset signal shaping means 23. The reset signal shaping unit 23 generates a reset signal that resets the first count signal of the up / down counter 24 when the neutral point position signal Cw is input, and inputs the reset signal to the reset terminal.

The first count signal output from the up / down counter 24 is connected to the operation angle calculation means 29. The operation angle calculation means 29 searches the steering angle map 27 and calculates the steering angle. The steering angle map 27 has a configuration in which the count value of the up / down counter 24 is associated with the steering angle. The output of the operation angle calculation unit 29 is connected to the output circuit 31 and the angle difference signal calculation unit 32.
In addition to the actual steering angle, the angle difference signal calculating unit 32 receives a steering angle signal of the second control device 7 via the steering angle signal receiving unit 33. The calculation result of the angle difference of the actual steering angle with respect to the steering angle is input to the steering reaction force calculation unit 34 as the output of the angle difference signal calculation unit 32.

  The steering reaction force calculation means 34 searches the steering reaction force map 35 and calculates the steering reaction force generated by the drive motor 12. The steering reaction force map 35 has a configuration in which the angle difference and the steering reaction force are associated with each other. The magnitude and direction of the steering reaction force are selected so that the steering angle matches the steering angle. The output of the steering reaction force calculation means 34 is connected to the drive signal generation means 36. The drive signal generation unit 36 receives the output of the steering reaction force calculation unit 34 and the output of the rack end reaction force signal generation unit 37, generates a drive signal for the drive motor 12, and outputs the drive signal to the drive circuit 15. The rack end reaction force signal generator 37 is connected to the output of the rack end signal detector 38. The rack end signal detection means 38 receives a rack end signal output from the second control device 7 when it hits the rack end.

  As shown in FIG. 2, the steering gear 5 includes a steering motor 41 in which a reduction mechanism is attached to an electric motor as driving means, and a rack and pinion mechanism that converts rotation of the steering motor 41 into linear motion of the steering rod 42. I have. The tire 4 is connected to both ends of the steering rod 42 via a tie rod 43 and a knuckle arm 44. The steering motor 41 is connected to the second control device 7 via the drive circuit 45. The drive circuit 45 includes a switching element and the like, and is configured to supply a current from a power source (not shown) to the steering motor 41.

A third encoder 46 that detects the steering angle from the rotation of the steering motor 41 is attached to the steering motor 41. The third encoder 46 uses an optical rotary encoder as described above. From the third encoder 46, the A-phase rotation detection signal Ag, which is the fourth pulse train signal, and the B-phase rotation detection signal Bg, which is the fifth pulse train signal whose pulse generation timing is shifted by ¼ cycle, Is output.
A fourth encoder 47 that detects a neutral point of the steering angle is attached to the steering gear 5 as a center position detection sensor that detects a position at which the steering angle is reset. The fourth encoder 47 detects the neutral point of the steering angle by detecting the intermediate point between the rack end where the tie rod 43 has moved to the right and the rack end where it has moved to the left. A marking (not shown) that moves together with 43 is detected, and one neutral point position signal Cg (see FIG. 3) is output as an initial position signal. The neutral point position signal Cg is a pulse signal having a duration that is longer than ½ of each cycle of the rotation detection signals Ag and Bg and shorter than each cycle of the rotation detection signals Ag and Bg.

The second control device 7 includes, as second counting means, an up / down determination circuit 51 to which the rotation detection signals Ag and Bg are input, an edge detection means 52A to which the rotation detection signal Ag is input, and rotation detection. An edge detecting means 52B to which the signal Bg is inputted and an up / down counter 54 as a second counter are provided.
The output of the up / down determination circuit 51 is connected to an up / down counter 54 as a second counter and a rack end determination means 71.
The up / down counter 54 is connected to the outputs of the edge detection means 52A and 52B via the OR circuit 55, and to the output of the up / down determination circuit 51 and the output of the reset signal shaping means 53. The reset signal shaping means 53 generates a reset signal for resetting the second count signal of the up / down counter 54 when the neutral point position signal Cg is inputted, and inputs the reset signal to the reset terminal.

The second count signal output from the up / down counter 54 is input to the steering angle calculation means 59. The steering angle calculation means 59 searches the steering angle map 60 and calculates the steering angle. The steering angle map 60 has a configuration in which the second count value of the up / down counter 54 is associated with the steering angle. The steering angle signal is output to the steering angle signal receiving means 33 (see FIG. 1) of the first control device 6 through the output circuit 61 and also to the rack end determination means 71. Further, it is also connected to the angle difference signal calculation means 62 and the angle comparison means 72.
The rack end determination unit 71 sends a signal to the rack end signal generation unit 74 when the count value of the timer 73 reaches a predetermined value. The rack end signal generation means 74 generates a rack end signal and transmits it to the first control device 6 through the output circuit 61.
The angle comparison means 72 is configured to be able to refer to data registered in the memory 75. The memory 75 stores the steering angle before a predetermined time. The data in the memory 75 is rewritten as needed by the angle comparison means 72.

  A steering angle signal transmitted from the output circuit 31 of the first control device 6 is input to the angle difference signal calculating means 62 via the steering angle signal receiving means 63. The output of the angle difference signal calculating means 62 is connected to the steering angle determining means 64. The steering angle determination means 64 searches the target steering angle map 65 and calculates the target steering angle. The target steering angle map 65 is set so that the output becomes large when the angle difference with respect to the actual steering angle is large. The target steering angle signal is converted into a drive signal by the drive signal generation means 66 and output to the drive circuit 45.

The current supplied from the drive circuit 45 to the steering motor 41 is monitored by a current sensor 81. The output of the current sensor 81 is input to the current comparison unit 83 via the current detection circuit 82. The current comparison unit 83 compares the current value detected by the current sensor 81 with the threshold value registered in the memory 84. When the current value exceeds the threshold value, a signal is output to the rack end determination means 71 and the current reduction signal generation circuit 85.
The current reduction signal generation circuit 85 also receives the outputs of the rack end determination means 71 and the angle comparison means 72, outputs a current reduction signal to the drive signal generation means 66, and outputs a current command value. Reduce.

Next, the operation of this embodiment will be described.
When the driver rotates the steering wheel 2, two pulse train signals (rotation detection signals Aw, Bw) are output to the first control device 6 according to the rotation angle from the first encoder 13. The up / down determination circuit 21 determines the rotation direction of the steering wheel 2 from the order in which the signal levels of the pulse train signals of the rotation detection signal Aw and the rotation detection signal Bw change. In the direction indicated by the arrow AA1 in FIG. 3, the rotation detection signal Bw becomes high level after the rotation detection signal Aw becomes high level. In this case, for example, it is assumed that the steering wheel 2 is steered rightward, and the up / down counter 24 is instructed to count up. When the steering wheel 2 is rotated in the reverse direction, each pulse is output in the direction opposite to the arrow AA1, that is, in the direction indicated by the arrow AA2. In this case, since the rotation detection signal Aw becomes high level after the rotation detection signal Bw becomes high level, the up / down determination circuit 21 instructs the up / down counter 24 to count down.

The edge detection unit 22A detects the rising edge and the falling edge of the pulse of the rotation detection signal Aw, and outputs them to the OR circuit 25. Similarly, the edge detection unit 52B detects the rising edge and the falling edge of the pulse of the rotation detection signal Bw, and outputs them to the OR circuit 25. The OR circuit 25 calculates the logical sum of the signals of both edge detection means 52A and 22B, and creates a signal such that a pulse rises when one of the edge detection means 22A and 22B detects an edge. As a result, the resolution of the pulse signal output from the first encoder 13 is quadrupled.
The up / down counter 24 counts pulse signals output from the OR circuit 25 with reference to a neutral point position corresponding to straight traveling of the vehicle. When the up / down determination circuit 21 instructs to count up, the input pulse is added to the count value of the number of pulses up to the previous time. When the up / down determination circuit 21 instructs to count down, the input pulse is subtracted from the count value of the number of pulses up to the previous time.

  The operation angle calculation means 29 searches the steering angle map 27 with the first count signal output as the count value of the up / down counter 24, and acquires the actual steering angle corresponding to the first count signal. An actual steering angle signal (steering angle degree signal) is transmitted from the output circuit 31 to the second control device 7.

In the second control device 7, the steering angle signal is received by the steering angle signal receiving means 63. The angle difference signal calculation means 62 calculates a steering angle corresponding to the actual steering angle (hereinafter referred to as a target steering angle). Further, the difference between the current steering angle of the tire 4 calculated by the steering angle calculation means 59 (hereinafter referred to as the actual steering angle) and the target steering angle is calculated and output as an angle difference signal.
The steering angle determination means 64 searches the target steering angle map 65 with the angle difference signal to determine the steering angle command value. This command value corresponds to a steering angle such that the angle difference is zero. The drive signal generating unit 66 creates a drive signal corresponding to the command value and outputs it to the drive circuit 45, rotates the steering motor 41, and moves the steering rod 42. As a result, the angle of the tire 4 connected by the tie rod 43 or the like changes.

When the steering motor 41 rotates, two types of rotation detection signals Ag and Bg are output from the third encoder 46. The second control device 7 determines the rotation direction from the change in the signal level of each pulse train signal of each rotation detection signal Ag, Bg by the up / down determination circuit 51. The determination algorithm is the same as that of the up / down determination circuit 21 of the first control device 6. Further, the edge detection means 52A, 52B and the OR circuit 55 generate a pulse signal having a resolution four times that of the rotation detection signals Ag, Bg.
The up / down counter 54 counts up or down the pulse signal output from the OR circuit 55 in accordance with a command from the up / down determination circuit 51. The steering angle calculation means 59 searches the steering angle map 60 with the second count signal output as the count value of the up / down counter 54, and the steering angle calculation means 59 searches the steering angle map 60 with the count value. And determine the actual steering angle. The actual steering angle signal (steering angle signal) is input to the angle difference signal calculating means 62 and the steering angle determining means 64 and used for controlling the steering motor 41. Further, it is sent from the output circuit 61 to the first control device 6.

  In the first control device 6, the steering angle signal is received by the steering angle signal receiving means 33, and the steering angle corresponding to the actual steering angle (hereinafter referred to as the target steering angle) is calculated by the angle difference signal calculating means 32. To do. Further, an actual steering angle (hereinafter referred to as an actual steering angle) calculated by the operation angle calculation unit 29 is acquired as a steering angle signal, and an angle difference between the actual steering angle and the target steering angle is calculated. The steering reaction force calculation means 34 searches the steering reaction force map 35 using the angle difference signal obtained at this time, and the steering reaction force is determined. The drive signal generation unit 36 generates a drive signal for the drive motor 12 according to the steering reaction force, and energizes the drive motor 12 from the drive circuit 15. A force is generated by the rotation of the drive motor 12 on the steering shaft 3 that is a rotating shaft connected to the drive motor 12. This force acts as a load for the driver who operates the steering wheel 2. As a result, the steering angle of the steering wheel 2 and the actual steering angle of the tire 4 quickly coincide with each other. In addition, information such as road surface conditions is transmitted to the driver, improving operability.

  Here, when the steering gear 5 moves to the rack end, the tire 4 cannot be steered any further. In this case, since the second encoder 46 attached to the steering motor 41 does not output a pulse signal, the pulse signal is not output from the OR circuit 55 to the rack end determination means 71.

  At this time, if the steering wheel 2 is further rotated without noticing that the driver has reached the rack end, the steering angle of the tire 4 cannot be increased any more, and therefore the difference between the steering angle and the steering angle becomes large. The current supplied to the directional motor 41 increases. When the detection value of the current sensor 81 exceeds the data registered in the memory, the current comparison unit 83 outputs a signal to each of the rack end determination unit 71 and the current reduction signal generation circuit 85.

  The rack end determination unit 71 monitors the steering angle signal input from the steering angle calculation unit 59 and the outputs of the OR circuit 55 and the current comparison unit 83. When the steering angle is an angle corresponding to the rack end, and the pulse signal from the OR circuit 55 is not input and the signal from the current comparison unit 83 is input, the timer 73 is started to wait in advance. Wait until time has passed. When there is no change in the steering angle signal, the pulse signal from the OR circuit 55, and the signal input from the current comparison means 83 even after the standby time has elapsed, the rack end signal generation means 74 and the current reduction signal generation circuit A signal is output to 85, and a rack end signal notifying that the rack end has been reached is output from the rack end signal generating means 74. The rack end signal is transmitted from the output circuit 61 to the first control device 6 and input to the rack end signal detecting means 38.

  When the current reduction signal generation circuit 85 receives a signal from the angle comparison means 72 in addition to the signal from the current comparison means 83, the current reduction signal generation circuit 85 outputs a current reduction signal to the drive signal generation means 66. The angle comparison means 72 outputs a signal when there is no difference between the steering angle registered in the memory 75 for a predetermined time and the current steering angle newly input. For this reason, the current reduction signal generation circuit 85 exceeds the rack end when the rack end determination means 71 outputs the rack end signal when the current input to the drive motor 41 is large and there is no change in the angle of the tire 4. It determines that it is going to steer and outputs a current reduction signal. Receiving this, the drive signal generating means 66 causes the drive circuit 45 to output a drive signal with a reduced current target value, and reduces the current input to the steering motor 41.

  In the first control device 6, when a signal indicating that the rack end has been reached is received by the rack end signal detection means 38, a rack end reaction force signal is output from the rack end reaction force signal generation means 37 to the drive signal generation means 36. Let When the drive signal generating means 36 receives the rack end reaction force signal, the current instruction value corresponding to the steering reaction force determined by the steering reaction force calculating means 34 is multiplied by a predetermined count to increase the current instruction value. Then, a drive signal based on the increased current command value is created. As a result, the current supplied to the drive motor 12 increases, and a steering reaction force larger than the reaction force due to the angle difference is generated in the steering shaft 3. The driver feels that the reaction force has increased and hit the rack end, and returns the steering wheel 2 or stops the rotation.

In this embodiment, the steering reaction force applied to the steering wheel 2 is increased when it is determined that the rack end is reached on the steering gear 5 side. The rack end reaction force, which is the steering reaction force at this time, is larger than the reaction force generated based on the difference between the steering angle and the steering angle, so that the driver can easily feel the rack end feeling. It is possible to prevent the steering wheel 2 from being turned more than necessary, and to prevent the current from continuing to flow when the steering motor 41 is locked.
The determination of the rack end arrival is made by monitoring the current input to the steering motor 41 and the steering angle, so that the current only increases during the steering, When the angle does not change, it is not determined that the rack end has been reached, and the accuracy of the determination process is improved. The rack end determination means 71 uses the timer 73 to generate a rack end signal when a predetermined time elapses in which it can be considered that the rack end has been reached, so that malfunction is prevented.
When it is determined that the rack end is reached, the current supplied to the steering motor 41 is reduced by the current reduction signal generation circuit 85, so that the steering motor 41 can be prevented from being locked. Since the current reduction signal is output when the current value increases while the steering angle does not change, the actual steering angle with respect to the target steering angle or when the tire 4 is not being steered. Malfunctions can be prevented when the difference is only large.

Note that the present invention can be widely applied without being limited to the above-described embodiment.
For example, you may comprise the 1st, 2nd control apparatuses 6 and 7 from one control apparatus.

It is a block diagram which shows the structure by the side of the steering wheel of the control apparatus for vehicles which concerns on embodiment of this invention. It is a block diagram which shows the structure by the side of the steering gear of the control apparatus for vehicles. It is a figure explaining the signal input into an up / down counter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus for vehicles 2 Steering wheel 3 Steering shaft 4 Tire (steering wheel)
5 Steering gear (drive means)
6 first control device 7 second control device 12 drive motor 13 first encoder 15 drive circuit 24 up / down counter (first count means)
29 steering angle calculation means 32 angle difference signal calculation means 36 drive signal generation means 37 rack end reaction force generation means 41 steering motor (drive means)
46 Third encoder 54 Up / down counter (second counting means)
59 Steering angle calculation means 71 Rack end determination means 72 Angle comparison means 74 Rack end signal generation means 81 Current sensor 83 Current comparison means 85 Current reduction signal generation circuit

Claims (3)

A steering shaft rotatably supported on the vehicle body;
A steering wheel attached to the steering shaft and rotating together with the steering shaft;
A first encoder for detecting rotation of the steering shaft;
First counting means for counting pulse signals detected by the first encoder and generating a first count signal;
Steering angle calculation means for converting the first count signal output from the first counting means into a signal indicating the amount of rotation of the steering wheel and outputting as a steering angle signal;
A steering wheel supported to be steerable by a vehicle body;
A drive unit having an electric motor and a rack and pinion mechanism, and changing a steering angle of the steering wheel with respect to a vehicle body;
A change in the steering angle of the steering wheel is detected, a detection signal supplied from an encoder that generates a detection signal in accordance with a change in the steering angle of the steering wheel is counted, and a second count signal is output. A second counting means;
Steering angle calculation means for converting the second count signal supplied from the second counting means into a signal indicating the amount of change in the steering angle of the steering wheel, and outputting as a steering angle signal;
An angle difference signal calculating means for generating an angle difference signal corresponding to a difference between the steering angle signal calculated by the steering angle calculating means and the steering angle signal calculated by the steering angle calculating means;
An angle difference signal is supplied from the angle difference signal calculating means, a drive signal is generated based on the angle difference signal, and a drive signal is generated so that the steering angle signal matches the steering angle signal. When,
A drive circuit for receiving a drive signal and supplying a current to the drive motor;
When receiving a rack end signal indicating that the rack of the rack and pinion mechanism has reached the rack end, the rack end generates a reaction force signal that increases the current supplied to the drive motor from a value determined by the angle difference signal. A vehicle control device comprising reaction force signal generating means.   A current sensor for detecting a current supplied to the steering motor; and a rotation angle of the steering motor at a steering angle corresponding to a rack end; and the current supplied to the steering motor has a predetermined value. The vehicle control apparatus according to claim 1, further comprising a rack end determination unit that generates a rack end signal when exceeding.   A current reduction signal generating circuit for reducing a current supplied to the steering motor when a current supplied to the steering motor exceeds a predetermined value without changing a steering angle of the steering wheel; The vehicle control device according to claim 2.

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