KR102420320B1 - Power steering apparatus for vehicle and control method thereof - Google Patents

Abstract

Without installing a steering angle sensor for detecting the steering angle of the steering shaft and a torque sensor for detecting the steering torque of the steering shaft on the steering shaft, the steering angle and steering torque of the steering shaft are calculated through the sensor provided in the motor of the power steering device. , a vehicle power steering apparatus capable of assisting the steering torque and a control method thereof are provided.
To this end, the power steering device for a vehicle according to the present invention is a power steering device for a vehicle in which a driver assists a steering torque for rotating a steering shaft by using a driving force of a motor, wherein the motor by the steering torque for rotating the steering shaft A first sensor for detecting the rotation speed of the rotation shaft when the rotation shaft of A controller for calculating an assist torque using the rotational speed of the rotational shaft detected by the first sensor and the rotational position of the rotational shaft detected by the second sensor and controlling the rotational shaft to rotate with the calculated assist torque, The first sensor and the second sensor are disposed within the motor.

Description

Power steering device for vehicle and control method thereof

The present invention relates to a vehicle power steering apparatus and a control method thereof, and more particularly, to a vehicle power steering apparatus using a motor and a control method thereof.

In general, a steering system of a vehicle is a system in which a driver steers wheels in a direction in which a driver turns a steering wheel left and right. and a steering gear having a shaft, a pinion shaft coupled to a lower end of the intermediate shaft through a universal joint, and a rack meshing with a pinion formed on the pinion shaft.

When the driver rotates the steering wheel, the steering shaft, the intermediate shaft, and the pinion shaft are rotated together in the same direction as the steering wheel, and accordingly, the rack bar included in the steering gear is linearly moved left and right, and the When the tie rods respectively coupled to both ends of the rack bar rotate the knuckles coupled to the wheel of the wheel, the wheel is steered in the rotational direction of the steering wheel.

Meanwhile, when the driver rotates the steering wheel, a power steering device is installed in the steering system so that the steering wheel can be rotated with a small force.

In the power steering apparatus, when the driver rotates the steering shaft, the electric motor installed on the pinion shaft is controlled according to the detection value of the sensor for detecting the driver's steering intention, size, and direction, so that the electric motor rotates the pinion shaft By doing so, the driver can rotate the steering wheel with little force.

As an example of a steering system for a vehicle in which a power steering device using the electric motor is installed, Republic of Korea Patent Publication No. 10-1713265 (2017.03.07. Announcement) (hereinafter referred to as 'prior art 1') has a 'planetary gear' A reduced gear and a steering device for a vehicle including the same are disclosed.

The prior art 1 includes an input shaft and a pinion shaft connected to the input shaft via a torsion bar. After the input shaft and the pinion shaft are first integrally coupled, the integrally coupled input shaft and the pinion shaft are integrated into the motor and the reducer. rotatably installed on the

As such, in the prior art 1, since the input shaft and the pinion shaft were first coupled and then rotatably installed inside the motor and the reducer, the installation work of the input shaft and the pinion shaft was complicated.

Meanwhile, the power steering apparatus uses a torque and angle sensor to transmit the driver's steering intention, size, and direction to an electronic control unit (ECU). Using these sensors, the steering torque, which is the physical energy applied by the driver to the steering wheel, generates an electrical resistance difference according to the amount of mechanical torsion, and the resulting voltage change is converted into electrical energy and output.

The EUC receives 12V electrical energy and controls the rotation speed and position of the motor according to the vehicle speed according to the gain map designed in advance. The driver is helped to change the direction of travel of the vehicle with the help of the torque generated by controlling the rotational speed and position of the motor.

As an example of a device that assists a driver's steering force through the motor control using the torque and angle sensor, Korean Patent Publication No. 10-2026601 (2019.09.30. Announcement) (hereinafter referred to as 'prior art 2') 'MDPS motor control method' is disclosed. However, the power steering device using a motor as in the prior art 2 helps to reduce steering force, provides steering control force, and driving stability to the driver, but the system configuration (parts) price (unit price) is relatively higher than that of the hydraulic steering control device. In addition, there is a problem in that the failure rate due to the sensor is high.

On the other hand, the electric steering control apparatus as in the prior art 1 and the prior art 2 is applied to most internal combustion engine vehicles and electric vehicles, and is a device that provides a driver with reduced steering force, steering operation force, and driving stability.

This is not a problem because internal combustion engine vehicles and current electric vehicles have a separate space for installing the battery for the power steering device. It is difficult, and if the current steering system is applied as it is, problems such as efficiency and heat generation may occur because the high voltage battery used for driving driving has to be used for the power steering device by deliberately dropping the voltage according to the supply voltage.

Republic of Korea Patent Publication No. 10-1713265 (2017.03.07. Announcement) Republic of Korea Patent Publication No. 10-2026601 (2019.09.30. Announcement)

The problem to be solved by the present invention is, without installing a steering angle sensor for detecting a steering angle of a steering shaft and a torque sensor for detecting a steering torque of the steering shaft on the steering shaft, through a sensor provided in a motor of a power steering device. An object of the present invention is to provide a power steering apparatus for a vehicle capable of calculating a steering angle and a steering torque of an axis to assist the steering torque, and a method for controlling the same.

Another problem to be solved by the present invention is to configure the motor of the power steering device as a high-voltage motor and a low-voltage motor so that it can be operated by the current of the vehicle driving battery or the current of the vehicle's electrical components, thereby operating the power steering device. An object of the present invention is to provide a power steering device for a vehicle that can be operated without a separate battery and a method for controlling the same.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a power steering apparatus for a vehicle according to the present invention assists a steering torque that a driver rotates a steering shaft by using a driving force of a motor. A power steering apparatus for a vehicle according to the present invention includes a first sensor, a second sensor, and a controller. The first sensor is disposed within the motor. The first sensor senses the rotation speed of the rotation shaft when the rotation shaft of the motor is rotated by the steering torque for rotating the steering shaft. The second sensor is disposed within the motor. The second sensor detects a rotational position of the rotation shaft when the rotation shaft is rotated by the steering torque for rotating the steering shaft. The controller calculates an assist torque by using the rotation speed of the rotation shaft detected by the first sensor and the rotation position of the rotation shaft detected by the second sensor, and rotates the rotation shaft with the calculated assistance torque control

The first sensor may be an encoder. The second sensor may be a Hall sensor.

The controller may include a steering angular velocity calculator, a steering angle calculator, an assist torque calculator, and a motor controller. The steering angular velocity calculator may calculate the steering angular velocity of the steering shaft by using the rotational speed of the rotation shaft sensed by the first sensor. The steering angle calculator may calculate the steering angle of the steering shaft by using the rotation position of the rotation shaft detected by the second sensor. The assist torque calculator may calculate the assist torque by using the calculated steering angular velocity and the calculated steering angle. The motor control unit may control the rotation shaft to rotate with the calculated assist torque.

The steering angle calculation unit further uses the speed of the vehicle detected by the vehicle speed sensor, the yaw rate at which the vehicle is rotated based on the vertical axis detected by the yaw rate sensor, and the lateral acceleration of the vehicle detected by the lateral acceleration sensor Thus, the steering angle of the steering shaft may be calculated.

The motor may be composed of a high voltage motor and a low voltage motor. The high voltage motor and the low voltage motor may have the rotation shaft in common. When it is possible to supply a voltage from the driving battery of the vehicle, the controller may control the rotation shaft to rotate with the calculated assist torque by supplying a current of the driving battery to the high voltage motor. In addition, when it is impossible to supply voltage from the driving battery of the vehicle, the controller supplies the electric current operated by the current of the driving battery to the low voltage motor to control the rotation shaft to rotate with the calculated assist torque. have.

In the method of controlling a power steering apparatus for a vehicle according to the present invention, a driver assists a steering torque for rotating a steering shaft by using a driving force of a motor. The control method of a power steering apparatus for a vehicle according to the present invention includes a motor rotation shaft rotation speed sensing step, a motor rotation shaft rotation position detection step, and a steering assistance step. In the step of detecting the rotational speed of the motor rotation shaft, when the rotation shaft of the motor is rotated by the steering torque for rotating the steering shaft, a first sensor disposed in the motor senses the rotation speed of the rotation shaft. In the step of detecting the rotational position of the motor rotational shaft, when the rotational shaft is rotated by the steering torque for rotating the steering shaft, a second sensor disposed in the motor senses the rotational position of the rotational shaft. In the steering assistance step, an assist torque is calculated using the rotation speed of the rotation shaft detected by the first sensor and the rotation position of the rotation shaft detected by the second sensor, and the rotation shaft is control to rotate.

In the steering assist step, when a voltage can be supplied from the driving battery of the vehicle, a current of the driving battery may be supplied to the high voltage motor to control the rotation shaft to rotate with the calculated assist torque. In addition, in the steering assistance step, when it is impossible to supply voltage from the driving battery of the vehicle, the electric current of the electric device operated by the current of the driving battery is supplied to the low voltage motor to control the rotation shaft to rotate with the calculated assist torque. can do.

The details of other embodiments are included in the detailed description and drawings.

A power steering apparatus for a vehicle and a control method thereof according to the present invention include a rotation speed of a rotation shaft of a motor detected by a first sensor disposed in a motor, and a rotation speed of the rotation shaft detected by the second sensor disposed in the motor. Since the assist torque is calculated using the rotation position and the rotation shaft is controlled to rotate with the calculated assist torque, without installing a steering angle sensor and a torque sensor on the steering shaft, the first sensor provided in the motor and There is an effect of assisting the steering torque by calculating the steering angle and the steering torque of the steering shaft through the second sensor.

In addition, in the power steering apparatus for a vehicle and a control method thereof according to the present invention, the motor is composed of a high-voltage motor and a low-voltage motor having a common rotation shaft, so that the high-voltage motor is operated by a current of a vehicle driving battery, When the high-voltage motor cannot be operated by the current of the driving battery of the vehicle, the low-voltage motor is operated by the current of the electrical equipment installed in the vehicle. Accordingly, since a separate battery for operating the power steering device is not required, there is an effect that can be applied to a vehicle with a narrow space, such as an ultra-small electric vehicle.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a perspective view showing a steering system of a vehicle in which a power steering apparatus for a vehicle according to an embodiment of the present invention is installed;
2 is a perspective view showing a state in which the power steering device shown in FIG. 1 is separated from the steering gear;
3 is a view schematically showing a steering system of a vehicle in which a power steering apparatus for a vehicle according to an embodiment of the present invention is installed;
4 is a control block diagram of a power steering apparatus for a vehicle according to an embodiment of the present invention;
5 is a flowchart according to a control method of a power steering apparatus for a vehicle according to an embodiment of the present invention;
6 is a detailed flowchart of the motor control step shown in FIG. 5 .

Hereinafter, a power steering apparatus for a vehicle and a control method thereof according to an embodiment of the present invention will be described with reference to the drawings.

1 is a perspective view illustrating a steering system of a vehicle in which a power steering apparatus for a vehicle according to an embodiment of the present invention is installed, and FIG. 2 is a perspective view illustrating a state in which the power steering apparatus shown in FIG. 1 is separated from a steering gear.

1 and 2 , a steering system of a vehicle in which a power steering apparatus 400 for a vehicle is installed according to an embodiment of the present invention includes a steering column 100 , a steering shaft 200 , and an intermediate shaft. 300 , a power steering device 400 , and a steering gear 500 may be included.

A bracket may be installed on the outer periphery of the steering column 100 , and the bracket may be coupled to a vehicle body to support the steering column 100 . The steering column 100 may rotatably support the steering shaft 200 .

The steering shaft 200 may vertically penetrate the steering column 100 . The upper end of the steering shaft 200 may protrude toward the upper end of the steering column 100 , and the lower end of the steering shaft 200 may protrude toward the lower end of the steering column 100 .

A steering wheel 10 that the driver holds by hand and rotates left or right to steer the wheel of the vehicle may be coupled to the upper end of the steering shaft 200 .

The lower end of the steering shaft 200 may be coupled to the intermediate shaft 300 through the universal joint 310 . That is, the upper end of the intermediate shaft 300 may be coupled to the lower end of the steering shaft 200 through the universal joint 310 .

The lower end of the intermediate shaft 300 may be coupled to the input shaft 420 of the power steering apparatus 400 through the universal joint 320 . That is, the input shaft 420 of the power steering device 400 is disposed to protrude toward the upper end of the power steering device 400 , and may be coupled to the lower end of the intermediate shaft 300 through the universal joint 320 .

A pinion shaft 440 may be protruded from the lower end of the power steering device 400 . A pinion gear 441 may be formed on the outer periphery of the pinion shaft 440 . The pinion shaft 440 may be inserted into the housing 510 of the steering gear 500 , and in this state, the pinion gear 441 is disposed movably left and right inside the housing 510 of the steering gear 500 . It may mesh with a rack (not shown) formed on the rack bar 520 .

Tie rods 530 and 540 may be coupled to the left and right ends of the rack bar 520 , respectively. The tie rods 530 and 540 may include a left tie rod 530 connected to the knuckle of the left wheel and a right tie rod 540 connected to the knuckle of the right wheel.

When the pinion shaft 440 is rotated in one direction, the rack bar 520 may be linearly moved to the left, and accordingly, the left tie rod 530 and the right tie rod 540 are linearly moved to the left and coupled to the left and right wheels, respectively. By rotating the used knuckle to the left, the left and right wheels can be steered to the left.

In addition, when the pinion shaft 440 is rotated in the other direction, the rack bar 520 may be linearly moved to the right, and accordingly, the left tie rod 530 and the right tie rod 540 are linearly moved to the right to move the left and right wheels. By rotating the knuckles respectively coupled to the right side, the left and right wheels can be steered to the right.

3 is a diagram schematically illustrating a steering system of a vehicle in which a power steering apparatus for a vehicle according to an embodiment of the present invention is installed.

1 to 3 , the power steering apparatus 400 for a vehicle according to an embodiment of the present invention may include a motor 410 , an input shaft 420 , a reducer 430 , and a pinion shaft 440 . have.

The motor 410 may be an electric motor driven by electric energy. The motor 410 may have a hollow rotating shaft 411 . The hollow of the rotating shaft 411 may be formed to be long in the axial direction. The rotating shaft 411 may be formed to be elongated vertically, and the hollow of the rotating shaft 411 may be formed to be elongated vertically.

The motor 410 may be formed as a dual motor including a high voltage motor 41 and a low voltage motor 42 . The high voltage motor 41 and the low voltage motor 42 may have a rotation shaft 411 in common. Here, it should be noted that the meaning of having the rotating shaft 411 in common does not necessarily mean a single integrated rotating shaft. That is, the rotation shaft of the high voltage motor 41 and the rotation shaft of the low voltage motor 42 may be separately configured. In this case, the rotation shaft of the high voltage motor 41 and the rotation shaft of the low voltage motor 42 are coupled to each other and disposed on the same axis. it might be

The high voltage motor 41 may be operated by power of 144V, which is the voltage of the vehicle driving battery. In addition, the low-voltage motor 42 may be operated by a 12V power source used to operate the vehicle electrical equipment by dropping the voltage of the vehicle driving battery. A detailed description thereof will be described later with reference to FIG. 6 .

The input shaft 420 may pass through the hollow of the rotation shaft 411 . The input shaft 420 may be vertically elongated. The upper end of the input shaft 420 may protrude toward the upper end of the motor 410 .

The upper and lower ends of the input shaft 420 may be rotatably coupled to the inside of the housing of the power steering apparatus 400 through bearings.

In a state in which the input shaft 420 is installed to pass through the rotation shaft 411 of the motor 410 , the rotation shaft 411 and the input shaft 420 may be rotatable independently of each other. That is, the input shaft 420 passes through the hollow of the rotation shaft 411 , but may be rotatable with respect to the rotation shaft 411 .

The motor 410 may include a motor housing having upper and lower ends opened, respectively, and a motor cover covering the opened upper end of the motor housing. The motor housing and the motor cover may form an exterior of the motor 410 . The motor housing may have a cylindrical shape with upper and lower ends opened, respectively, and the motor cover may have a cylindrical shape with an open lower end to cover the opened upper end of the motor housing.

The upper end of the motor housing and the lower end of the motor cover may be fastened through a plurality of bolts.

The upper end of the input shaft 420 may pass through the center of the motor cover of the motor 410 to protrude upward of the motor 410 .

The reducer 430 may be coupled to the lower end of the motor 410 . A lower end of the input shaft 420 may be protruded from the lower end of the reducer 430 .

The reducer 430 may include a reduction gear housing having upper and lower ends opened, respectively, and a reduction gear cover covering the open lower end of the reduction gear housing. The reducer housing and the reducer cover may form the appearance of the reducer 430 . The reducer housing may be formed in a cylindrical shape with upper and lower ends opened, respectively, and the reducer cover may have a cylindrical shape with an open upper end to cover the open lower end of the reducer housing.

The reducer housing and the reducer cover may be fastened through a plurality of bolts.

In addition, the open lower end of the motor housing and the open upper end of the reducer housing may be disposed to contact each other. The lower end of the motor housing and the reducer housing may be fastened through a plurality of bolts.

The lower end of the input shaft 420 may pass through the center of the reducer cover of the reducer 430 to protrude downward of the reducer 430 .

The reducer 430 may reduce the rotation speed of the rotation shaft 411 and transmit it to the input shaft 420 . The reducer 430 may reduce the rotation speed of the rotation shaft 411 through a plurality of gears disposed therein and transmit it to the input shaft 420 . Here, the plurality of gears may be a planetary gear or a harmonic gear.

The plurality of gears include a sun gear (not shown) coupled to the outer periphery of the rotating shaft 411 and having gear teeth formed on the outer periphery, a ring gear (not shown) coupled to the inside of the reduction gear housing and formed with gear teeth on the inner periphery, the sun gear and It may include a plurality of planetary gears (not shown) disposed between the ring gears, and a carrier (not shown) connecting the plurality of planetary gears.

The plurality of planetary gears may be disposed to be spaced apart from each other along an outer periphery of the sun gear. The ring gear may be fixed to the inside of the reduction gear housing so as not to rotate in the circumferential direction. Each of the plurality of planetary gears may have gear teeth formed on its outer periphery, and gear teeth formed on the outer periphery of each of the plurality of planetary gears may mesh with the gear teeth of the sun gear and the gear teeth of the ring gear. The carrier may be coupled to the plurality of planetary gears and coupled to the outer periphery of the input shaft 420 .

Accordingly, when the rotation shaft 411 of the motor 410 rotates, the sun gear may rotate in the same direction as the rotation shaft 411 , and accordingly, the plurality of planetary gears may rotate in the opposite direction to the sun gear. Since the carrier is coupled to the plurality of planetary gears, when the plurality of planetary gears are rotated, they are rotated in the same direction as the plurality of planetary gears to rotate the input shaft 420 .

A pinion gear 441 may be formed on the outer periphery of the pinion shaft 440 . The pinion gear 441 may mesh with the rack of the rack bar 520 provided to be linearly movable in the left and right directions inside the housing 510 of the steering gear 500 .

The lower end of the input shaft 420 and the upper end of the pinion shaft 440 may be coupled by a coupling pin. That is, the coupling pin may couple the upper end of the pinion shaft 440 to the lower end of the input shaft 420 , which is a portion protruding toward the lower end of the reduction gear 430 . Accordingly, the pinion shaft 440 can be easily coupled to the input shaft 420 from the outside of the motor 410 and the reducer 430 .

A groove is formed at the upper end of the pinion shaft 440 in the axial direction, and the lower end of the input shaft 420 has a smaller diameter than the rest of the input shaft 420, so that the lower end of the input shaft 420 is the pinion shaft 440. It can be inserted into the groove formed at the top of the. Conversely, a groove may be formed at the lower end of the input shaft 420 in the axial direction, and in this case, the upper end of the pinion shaft 440 may be inserted into the groove formed at the lower end of the input shaft 420 .

At the lower end of the input shaft 420 and the upper end of the pinion shaft 440 , a coupling pin coupling hole into which the coupling pin is inserted and coupled may be formed. Each of the coupling pin coupling holes may be formed to radially communicate with the outer periphery of the lower end of the input shaft 420 and the outer periphery of the upper end of the pinion shaft 440 .

That is, the operator inserts the lower end of the input shaft 420 into the groove formed at the upper end of the pinion shaft 440, and then inserts the coupling pin into each of the coupling pin coupling holes, so that the upper end of the pinion shaft 440 is the input shaft. It can be coupled to the lower end of the (420).

Meanwhile, a power steering device mounting part 511 may be formed in the housing 510 of the steering gear 500 , and a screw thread may be formed on an inner circumferential surface of the power steering device mounting part 511 . In addition, on the outer circumferential surface of the portion inserted into the power steering device mounting part 511 of the housing of the power steering device 400, a thread screwed with the screw thread formed on the inner circumferential surface of the power steering device mounting part 511 is formed. The power steering device 400 according to the embodiment of the present invention may be installed in the power steering device mounting unit 511 of the steering gear 500 without a separate bracket.

As described above, in the power steering apparatus 400 for a vehicle according to an embodiment of the present invention, the driver uses the driving force of the motor 410 to apply the steering torque for rotating the steering shaft 200 while holding the steering wheel 10 by hand. can assist you. Conventionally, a torque sensor for detecting a steering torque for a driver to rotate the steering shaft 200 and a steering angle sensor for detecting a steering angle at which the driver rotates the steering shaft 200 were installed directly connected to the steering shaft 200 . . However, the power steering apparatus 400 of the vehicle according to the embodiment of the present invention uses the detection value of the sensor provided in the motor 410 without installing the torque sensor and the steering angle sensor on the steering shaft 200 . By controlling the motor 410, the steering torque may be assisted. This will be described in detail below.

4 is a control block diagram of a power steering apparatus for a vehicle according to an embodiment of the present invention.

Referring to FIG. 4 , the power steering apparatus 400 for a vehicle according to an embodiment of the present invention may further include a first sensor 480 , a second sensor 490 , and a controller 700 . Of course, since the controller 700 is a control unit for controlling the motor 410 using the respective detection values of the first sensor 480 and the second sensor 490, it is necessarily provided in the power steering device 400. It may be an ECU (Electronic Control Unit), which is a representative control unit of the vehicle.

The first sensor 480 and the second sensor 490 may be installed in the motor 410 . The first sensor 480 may be an encoder, and the second sensor 480 may be a Hall sensor.

When the rotation shaft 411 of the motor 410 is rotated by the steering torque that the driver rotates the steering shaft 200, the first sensor 480 detects the rotation speed of the rotation shaft 411 of the motor 410. can

When the rotation shaft 411 of the motor 410 is rotated by the steering torque that the driver rotates the steering shaft 200, the second sensor 490 detects the rotational position of the rotation shaft 411 of the motor 410. can

The rotation speed of the rotation shaft 411 detected by the first sensor 480 may be input to the controller 700 . Also, the rotation position of the rotation shaft 411 sensed by the second sensor 490 may be input to the controller 700 .

The controller 700 may calculate the assist torque using the rotation speed of the rotation shaft 411 detected by the first sensor 480 and the rotation position of the rotation shaft 411 detected by the second sensor 490 . The controller 700 has a function for calculating the assist torque by using the rotational speed of the rotational shaft 411 detected by the first sensor 480 and the rotational position of the rotational shaft 411 detected by the second sensor 490 as variables. A value can be set. Of course, in this embodiment, the input shaft 420 may be rotated at the same speed and the same angle as the steering shaft 200 , and by the gear ratio of the gear assembly 433 , the rotational speed of the rotating shaft 411 of the motor 410 is higher than that of the input shaft 420 . The rotation speed is reduced, and the rotation angle may be smaller than the rotation angle of the rotation shaft 411 of the motor 410 by the gear ratio of the gear assembly 433 . Accordingly, in the function value, the gear ratio of the gear assembly 433 may be further set to a fixed value.

When the rotation speed of the rotation shaft 411 is input from the first sensor 480 and the rotation position of the rotation shaft 411 is inputted from the second sensor 490, the controller 700 has the function value set in the controller 700 The assist torque may be calculated through .

The controller 700 may control the rotation shaft 411 of the motor 410 to rotate with the calculated assist torque. When the controller 700 controls the rotation shaft 411 of the motor 410 to rotate with the calculated assist torque, the driver may rotate the steering shaft 200 with a small force. Therefore, by controlling the motor 410 using the first sensor 480 and the second sensor 490 installed in the motor 410 without installing the torque sensor and the steering angle sensor on the steering shaft 200, The driver may assist the steering torque, which is a force that rotates the steering shaft 200 .

The controller 700 may include a steering angular velocity calculator 710 , a steering angle calculator 720 , an assist torque calculator 730 , and a motor controller 740 .

The rotation speed of the rotation shaft 411 detected by the first sensor 480 may be input to the steering angular velocity calculator 710 , and the steering angular velocity calculator 710 may be inputted from the first sensor 480 to the rotation shaft 411 . ) can be used to calculate the steering angular velocity of the steering shaft 200 .

In the steering angular velocity calculator 710 , a function value for calculating the steering angular velocity of the steering shaft 200 by using the rotational speed of the rotation shaft 411 sensed by the first sensor 480 as a variable may be set. Of course, the function value set in the steering angular velocity calculator 710 may further set the gear ratio of the gear assembly 433 to a fixed value.

When the rotation speed of the rotation shaft 411 is input from the first sensor 480 , the steering angular velocity calculation unit 710 calculates the steering angular velocity of the steering shaft 200 through the function value set in the steering angular velocity calculation unit 710 . can do.

The rotational position of the rotation shaft 411 detected by the second sensor 480 may be input to the steering angle calculator 720 , and the steering angle calculator 720 may be inputted from the second sensor 490 to the rotation shaft 411 . ) can be used to calculate the steering angle of the steering shaft 200 .

In the steering angle calculator 720 , a function value for calculating the steering angular velocity of the steering shaft 200 by using the rotation position of the rotation shaft 411 sensed by the second sensor 490 as a variable may be set. Of course, in the function value set in the steering angle calculator 720 , the gear ratio of the gear assembly 433 may be further set to a fixed value.

When the rotation position of the rotation shaft 411 is input from the second sensor 490 , the steering angle calculator 720 calculates the steering angle of the steering shaft 200 through the function value set in the steering angle calculator 720 . can do.

The steering angular velocity of the steering shaft 200 calculated by the steering angular velocity calculator 710 may be input to the assist torque calculator 730 , and the steering angle of the steering shaft 200 calculated by the steering angle calculator 720 . may be input to the assist torque calculator 730 . The assist torque calculator 730 includes the calculated steering angular velocity of the steering shaft 200 input from the steering angular velocity calculator 710 and the calculated steering angular velocity of the steering shaft 200 input from the steering angle calculator 720 . The assist torque may be calculated using the steering angle.

In the assist torque calculator 730 , the steering angular velocity of the steering shaft 200 calculated by the steering angular velocity calculator 710 is used as a variable, and the steering angle of the steering shaft 200 calculated by the steering angle calculator 720 . As a variable, a function value for calculating the assist torque may be set.

The assist torque calculator 730 receives the steering angular velocity of the steering shaft 200 from the steering angular velocity calculator 710 and the steering angle of the steering shaft 200 from the steering angle calculator 720. When the steering angle is input, assist torque The assist torque may be calculated through the function value set in the calculator 730 .

The assist torque calculated by the assist torque calculating unit 730 may be input to the motor control unit 740 , and the motor control unit 740 may use the calculated assist torque input from the assist torque calculating unit 730 for the motor 410 . ) of the rotation shaft 411 can be controlled to rotate.

Meanwhile, the power steering apparatus 400 may control the motor 410 in association with the vehicle posture control apparatus (ESC). The attitude control device ESC may include a vehicle speed sensor 610 , a yaw rate sensor 620 , and a lateral acceleration sensor 630 . The vehicle speed sensor 610 may detect the speed of the vehicle, the yaw rate sensor 620 may detect the yaw rate at which the vehicle is rotated based on a vertical axis, and the lateral acceleration sensor 630 may detect the lateral speed of the vehicle. Directional acceleration can be detected.

The power steering apparatus 400 may include a power steering communication unit for receiving each of the detection values of the vehicle speed sensor 610 , the yaw rate sensor 620 , and the lateral acceleration sensor 630 . Here, the power steering communication unit may be a CAN communication unit.

The posture control device ESC may include an attitude control communication unit that communicates with the power steering communication unit of the power steering apparatus 400 . Here, the posture control communication unit may be a CAN communication unit.

When the detection value of each of the vehicle speed sensor 610, the yaw rate sensor 620, and the lateral acceleration sensor 630 is within the set value range, the controller 700 includes the first sensor 480, the second sensor 490, The motor 410 may be controlled using the respective detection values of the vehicle speed sensor 610 , the yaw rate sensor 620 , and the lateral acceleration sensor 630 . In addition, when at least one of the detection values of the vehicle speed sensor 610 , the yaw rate sensor 620 , and the lateral acceleration sensor 630 is out of the set value range, the controller 700 controls the vehicle speed sensor 610 , the yaw rate It is determined that at least one of the sensor 620 and the lateral acceleration sensor 630 has failed, and the motor 410 may be controlled using only the respective detection values of the first sensor 480 and the second sensor 490 .

When the power steering device 400 controls the motor 410 in conjunction with the attitude control device ESC, the vehicle speed detected by the vehicle speed sensor 610 and the yaw rate sensor 620 detected The yaw rate and the lateral acceleration of the vehicle detected by the lateral acceleration sensor 630 may be input to the steering angle calculator 720 .

When the power steering device 400 controls the motor 410 in conjunction with the posture control device ESC, the steering angle calculator 720 rotates the rotation shaft 411 input from the second sensor 490 . Using the position, the vehicle speed inputted from the vehicle speed sensor 610, the yaw rate inputted from the yaw rate sensor 620, and the lateral acceleration of the vehicle inputted from the lateral acceleration sensor 630, The steering angle of the steering shaft 200 may be calculated.

When the power steering device 400 controls the motor 410 in conjunction with the posture control device ESC, the steering angle calculator 720 includes the rotation position of the rotation shaft 411 detected by the second sensor 490 . and the vehicle speed detected by the vehicle speed sensor 610, the yaw rate detected by the yaw rate sensor 620, and the lateral acceleration of the vehicle detected by the lateral acceleration sensor 630. A function value for calculating the steering angular velocity of the shaft 200 may be set. Of course, in the function value set in the steering angle calculator 720 , the gear ratio of the gear assembly 433 may be further set to a fixed value.

When the power steering device 400 controls the motor 410 in conjunction with the posture control device (ESC), the steering angle calculation unit 720 determines the rotation position of the rotation shaft 411 from the second sensor 490 and, When the speed of the vehicle from the vehicle speed sensor 610, the yaw rate from the yaw rate sensor 620, and the lateral acceleration of the vehicle from the lateral acceleration sensor 630 are input, the steering angle calculation unit 720 is set The steering angle of the steering shaft 200 may be calculated through the function value.

5 is a flowchart illustrating a method for controlling a power steering apparatus for a vehicle according to an embodiment of the present invention. Here, the method for controlling the power steering apparatus for a vehicle according to an embodiment of the present invention will be described in connection with the operation of the power steering apparatus for a vehicle according to the embodiment of the present invention.

Referring to FIG. 5 , in the method of controlling the power steering apparatus 400 for a vehicle according to an embodiment of the present invention, the motor 410 is controlled using the detection step S10 and the detection value of the detection step S10 . It may include a steering assistance step (S20).

The detection step (S10) includes a motor rotation shaft rotation speed detection step (S11), a motor rotation shaft rotation position detection step (S12), a vehicle speed detection step (S13), a yaw rate detection step (S14), and a lateral acceleration detection step (S15) may be included.

In the motor rotation shaft rotation speed sensing step (S11), when the rotation shaft 411 of the motor 410 is rotated by the steering torque that the driver rotates the steering shaft 200, the first sensor disposed in the motor 410 ( 480 may detect the rotation speed of the rotation shaft 411 of the motor 410 . The sensed value for the rotation speed of the rotation shaft 411 of the motor 410 detected by the first sensor 480 in the motor rotation shaft rotation speed detection step S11 is input to the steering angular velocity calculation unit 710 of the controller 700 can be

In the motor rotation shaft rotation position sensing step (S12), when the rotation shaft 411 of the motor 410 is rotated by the steering torque that the driver rotates the steering shaft 200, the second sensor disposed in the motor 410 ( 490 may detect the rotational position of the rotation shaft 411 of the motor 410 . The sensed value for the rotational position of the rotational shaft 411 of the motor 410 detected by the second sensor 490 in the motor rotational shaft rotational position detection step S12 is input to the steering angle calculator 720 of the controller 700 can be

The vehicle speed detection step S13, the yaw rate detection step S14, and the lateral acceleration detection step S15 can be performed only when the left-right gradient of the driving road surface is equal to or greater than the set value, which is the value set in the controller 700.

In the vehicle speed detection step S13 , the vehicle speed sensor 610 may detect the speed of the vehicle. The sensed value for the vehicle speed detected by the vehicle speed sensor 610 in the vehicle speed detecting step S13 may be input to the steering angle calculating unit 720 of the controller 700 .

In the yaw rate detection step (S14), the yaw rate sensor 620 may detect the yaw rate. The sensed value for the yaw rate detected by the yaw rate sensor 620 in the yaw rate detection step S14 may be input to the steering angle calculator 720 of the controller 700 .

In the lateral acceleration detection step S15 , the lateral acceleration sensor 630 may detect the lateral acceleration of the vehicle. The sensed value for the rotational acceleration of the vehicle detected by the lateral acceleration sensor 630 in the lateral acceleration detection step S15 may be input to the steering angle calculator 720 of the controller 700 .

In the steering assistance step (S20), the assist torque is calculated using the rotational speed of the rotational shaft 411 detected by the first sensor 480 and the rotational position of the rotational shaft 411 detected by the second sensor 490. and the rotation shaft 411 of the motor 410 may be controlled to rotate with the calculated assist torque.

The steering assistance step S20 may include a steering angular velocity calculation step S21 , a steering angle calculation step S22 , an assist torque calculation step S23 , and a motor control step S24 .

In the steering angular velocity calculation step S21 , the steering angular velocity of the steering shaft 200 may be calculated using the rotational speed of the rotation shaft 411 detected by the first sensor 480 .

In the steering angle calculation step S22 , the steering angle of the steering shaft 200 may be calculated using the rotation position of the rotation shaft 411 detected by the second sensor 480 .

In the assist torque calculating step S23, the assist torque may be calculated using the steering angular speed calculated in the steering angular speed calculating step S21 and the steering angle calculated in the steering angle calculating step S22.

In the motor control step ( S24 ), the rotation shaft 411 of the motor 410 may be controlled to rotate with the calculated assist torque.

On the other hand, when the left-right gradient of the driving road surface is equal to or greater than the set value, which is the value set in the controller 700, in the steering angle calculation step S22, the vehicle speed detected by the vehicle speed sensor 610 and the yaw rate sensor 620 are The steering angle of the steering shaft 200 may be calculated by further using the detected yaw rate and the lateral acceleration of the vehicle detected by the lateral acceleration sensor 630 .

6 is a detailed flowchart of the motor control step shown in FIG. 5 . Here, the method for controlling the power steering apparatus for a vehicle according to an embodiment of the present invention will be described in connection with the operation of the power steering apparatus for a vehicle according to the embodiment of the present invention.

Referring to FIG. 6 , in the motor control step S24 , first, the controller 700 may determine whether the high voltage relay switch is in the ON state ( S241 ). Here, the high voltage relay switch may be a switch electrically connected to the driving battery of the vehicle. That is, when the high voltage relay switch is in an ON state, the current of the driving battery may be supplied to the controller 700 . Also, when the high voltage relay switch is in an OFF state, the current of the driving battery may not be supplied to the controller 700 .

That is, when a voltage can be supplied from the driving battery, the controller 700 may control the rotation shaft 411 to rotate with the calculated assist torque by supplying a current of the driving battery to the high voltage motor 41 .

In addition, when it is impossible to supply voltage from the driving battery, the controller 700 supplies the electric device current operated by the current of the driving battery to the low voltage motor 42 so that the rotation shaft 411 provides the calculated assist torque. can be controlled to rotate. Here, the electric device may be a component used in an air conditioning system of a vehicle, but is not limited thereto, and may be a multimedia device such as an audio device or a navigator installed in the vehicle, and is installed in the vehicle and operated by the current of the driving battery It can include all electrical equipment that can be used. Hereinafter, the current of the electric device will be described by limiting it to an air conditioning power source that is a current for operating a component used in the air conditioning system.

If the high voltage relay switch is not in the ON state as a result of the determination in step S241, the controller 700 may restart the motor 410 control system.

If the high voltage relay switch is in the ON state as a result of the determination in step S241, the controller 700 may determine whether a high voltage can be supplied from the driving battery (S242).

When it is determined that the high voltage can be supplied from the driving battery as a result of the determination in step S242, the controller 700 may receive the high voltage 144V power from the driving battery (S243).

The controller 700 may control the rotation shaft 411 to rotate with the calculated assist torque by supplying the 144V power supplied from the driving battery to the high voltage motor 41 ( S244 ).

The controller 700 may measure the voltage of the power supplied to the high voltage motor 41 and monitor it in units of 10 ms (S245).

Thereafter, the controller 700 may determine whether the high voltage motor 41 is a normal control operation (S246).

If the voltage measurement value of the power supplied to the high voltage motor 41 is within the first set value range for the first set time, the controller 700 may determine that the high voltage motor 41 is in normal control operation, and in this case, the controller ( 700) may end the logic.

In addition, if the voltage measurement value of the power supplied to the high voltage motor 41 is outside the first set value range for the first set time, the controller 700 may determine that the high voltage motor 41 is abnormally controlled. In this case, the controller 700 may output a failure notification to the user (S2421). Here, the failure notification may be at least one of a visual notification and an audible notification.

Meanwhile, when it is determined that the high voltage cannot be supplied from the driving battery as a result of the determination in step S242, the controller 700 may output a failure notification to the user (S2421).

After outputting the failure notification, the controller 700 may receive power of 12V, which is the air conditioning power, from the air conditioning system (S2422).

The controller 700 may control the rotation shaft 411 to rotate with the calculated assist torque by supplying the 12V power supplied from the air conditioning system to the low voltage motor 42 (S2423).

The controller 700 may measure the voltage of the power supplied to the low voltage motor 42 and monitor it in units of 5 ms (S2424).

The controller 700 may determine the normal control operation of the low voltage motor 42 when the voltage measurement value of the power supplied to the low voltage motor 42 is within the second set value range for the second set time. Here, the second set time may be a shorter time than the first set time, and the second set value may be a value lower than the first set value.

The controller 700 may determine whether the failure is recovered when the low-voltage motor 42 is normally operated (S2425).

The controller 700 may restart the control system of the motor 410 within 2 ms when it is determined that the failure is recovered as a result of the determination in step S2425 (S2426). After this, the logic may proceed to step S243.

On the other hand, if it is determined that the failure is not recovered as a result of the determination in step S2425, the controller 700 may output a failure notification to the user again (S2421).

As described above, in the vehicle power steering apparatus and the control method thereof according to the embodiment of the present invention, the rotation of the rotation shaft 411 of the motor 410 sensed by the first sensor 480 disposed in the motor 410 . Using the speed and the rotation position of the rotation shaft 411 sensed by the second sensor 490 disposed in the motor 410, an assist torque is calculated, and the rotation shaft 411 is controlled to rotate with the calculated assist torque. Therefore, the steering angle and steering of the steering shaft 200 through the first sensor 480 and the second sensor 490 provided in the motor 410 without installing the steering angle sensor and the torque sensor on the steering shaft 200 . It is possible to assist the steering torque by calculating the torque.

In addition, the vehicle power steering apparatus and the control method thereof according to the embodiment of the present invention, the motor 410 is composed of a high voltage motor 41 and a low voltage motor 42 having a common rotation shaft 411, When the high voltage motor 41 is operated by the current of the vehicle driving battery and the high voltage motor 41 cannot be operated by the current of the driving battery of the vehicle, the low voltage motor 42 is the current of the electric equipment installed in the vehicle. is operated by Accordingly, since a separate battery for operating the power steering apparatus 400 is not required, it can be applied to a vehicle having a narrow space, such as a micro electric vehicle.

Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

41 high voltage motor 42 low voltage motor
200: steering shaft 400: power steering device
410: motor 411: rotation shaft
480: first sensor 490: second sensor
610: vehicle speed sensor 620: yaw rate sensor
630: lateral acceleration sensor 700: controller
710: steering angular velocity calculation unit 720: steering angle calculation unit
730: assist torque calculation unit 740: motor control unit

Claims (7)

In the power steering apparatus 400 for a vehicle in which a driver assists a steering torque for rotating a steering shaft 200 by using a driving force of a motor 410,
When the rotating shaft 411 of the motor 410 is rotated by the steering torque for rotating the steering shaft 200, a first sensor 480 for detecting the rotational speed of the rotating shaft 411;
a second sensor 490 for detecting a rotational position of the rotating shaft 411 when the rotating shaft 411 is rotated by the steering torque for rotating the steering shaft 200; and
The assist torque is calculated using the rotation speed of the rotation shaft 411 detected by the first sensor 480 and the rotation position of the rotation shaft 411 detected by the second sensor 490, and the calculation A controller 700 for controlling the rotation shaft 411 to rotate with the assist torque;
The first sensor 480 and the second sensor 490 are disposed in the motor 410,
The motor 410 includes a high voltage motor 41 and a low voltage motor 42,
The high voltage motor 41 and the low voltage motor 42 have the rotating shaft 411 in common,
The controller 700,
When voltage supply is possible from the driving battery of the vehicle, the current of the driving battery is supplied to the high voltage motor 41 to control the rotation shaft 411 to rotate with the calculated assist torque,
When it is impossible to supply voltage from the driving battery of the vehicle, the electric current of the electric device operated by the current of the driving battery is supplied to the low voltage motor 42 to control the rotation shaft 411 to rotate with the calculated assist torque The vehicle's power steering system. The method according to claim 1,
The first sensor 480 is an encoder,
The second sensor 490 is a hall sensor, a power steering device for a vehicle. 3. The method according to claim 2,
The controller 700,
a steering angular velocity calculator 710 for calculating the steering angular velocity of the steering shaft 200 by using the rotational speed of the rotation shaft 411 sensed by the first sensor 480;
a steering angle calculator 720 for calculating a steering angle of the steering shaft 200 using the rotation position of the rotation shaft 411 detected by the second sensor 490;
an assist torque calculator 730 for calculating the assist torque by using the calculated steering angular velocity and the calculated steering angle; and
and a motor control unit (740) for controlling the rotation shaft (411) to rotate with the calculated assist torque. 4. The method of claim 3,
The steering angle calculator 720 includes the vehicle speed detected by the vehicle speed sensor 610, the yaw rate detected by the yaw rate sensor 620 at which the vehicle is rotated based on the vertical axis, and the lateral acceleration sensor 630 . ) further using the lateral acceleration of the vehicle sensed by ) to calculate the steering angle of the steering shaft 200 . delete In the control method of the power steering apparatus 400 of a vehicle, the driver assists the steering torque for rotating the steering shaft 200 by using the driving force of the motor 410,
When the rotation shaft 411 of the motor 410 is rotated by the steering torque that rotates the steering shaft 200 , the first sensor 480 disposed in the motor 410 moves the rotation shaft 411 . Motor rotation shaft rotation speed sensing step (S11) for detecting the rotation speed;
When the rotation shaft 411 is rotated by the steering torque for rotating the steering shaft 200, the second sensor 490 disposed in the motor 410 detects the rotational position of the rotation shaft 411 Motor rotation shaft rotation position detection step (S12); and
The assist torque is calculated using the rotation speed of the rotation shaft 411 detected by the first sensor 480 and the rotation position of the rotation shaft 411 detected by the second sensor 490, and the calculated A steering assistance step (S20) of controlling the rotation shaft 411 to rotate with an assist torque; and
The motor 410 includes a high voltage motor 41 and a low voltage motor 42,
The high voltage motor 41 and the low voltage motor 42 have the rotating shaft 411 in common,
In the steering assistance step (S20),
When voltage supply is possible from the driving battery of the vehicle, the current of the driving battery is supplied to the high voltage motor 41 to control the rotation shaft 411 to rotate with the calculated assist torque,
When it is impossible to supply voltage from the driving battery of the vehicle, the electric current of the electric device operated by the current of the driving battery is supplied to the low voltage motor 42 to control the rotation shaft 411 to rotate with the calculated assist torque A method of controlling a power steering device of a vehicle. delete

Images