JP7265372B2 - Steering control device, steering device, and vehicle - Google Patents

Description

The present invention relates to steering control devices, steering devices, and vehicles.

2. Description of the Related Art In automatic driving technology, a steering control device is known that performs steering control so that a moving object follows a target route. In addition, Patent Document 1 is cited as an example of an automatic driving technology that causes a moving object to follow a target route.

Patent No. 4297123

By the way, in a steering control device, it is preferable to perform steering control that provides a comfortable ride.

SUMMARY OF THE INVENTION An object of the present invention is to realize a steering control device that performs steering control that provides a comfortable ride.

For this purpose, a steering control device according to the present invention obtains a captured image of an imaging range including the front of the vehicle in a steering control device that calculates a steering control amount for controlling the steering of the vehicle. a captured image acquisition unit, a vehicle speed information acquisition unit that acquires vehicle speed information indicating the vehicle speed of the vehicle, a map GPS information acquisition unit that acquires map information and GPS information, a captured image acquired by the captured image acquisition unit, and a first target control amount calculation unit for calculating a first target control amount with reference to the vehicle speed information acquired by the vehicle speed information acquisition unit; to obtain the shape of the road in the traveling direction of the vehicle, calculate a route to be traced based on the shape of the road, and calculate a curvature to be traced based on the route to be traced. a second target control amount calculator that calculates a second target control amount based on the curvature to be traced; a first gain that is multiplied by the first target control amount; a gain calculation unit that calculates a second gain to be multiplied by the control amount,
A controlled variable for controlling the steering is calculated based on the first target controlled variable multiplied by the first gain and a second target controlled variable multiplied by the second gain.

According to the present invention, it is possible to perform steering control with good ride comfort.

1 is a diagram showing a schematic configuration of a vehicle according to Embodiment 1 of the present invention; FIG. 1 is a block diagram showing a schematic configuration of an ECU according to Embodiment 1 of the present invention; FIG. 3 is a block diagram showing a configuration example of a steering control unit according to Embodiment 1 of the present invention; FIG. FIG. 4 is a schematic diagram for explaining calculation processing of a curvature to be traced according to the first embodiment of the present invention; FIG. 4 is a schematic diagram for explaining calculation processing of a curvature to be traced according to the first embodiment of the present invention; FIG. 4 is a schematic diagram for explaining calculation processing of a curvature to be traced according to the first embodiment of the present invention; 4 is a flow chart showing the flow of steering control amount calculation processing according to the first embodiment of the present invention.

[Embodiment 1]
Embodiment 1 of the present invention will be described in detail below.

(Configuration of vehicle 900)
FIG. 1 is a diagram showing a schematic configuration of a vehicle 900 according to this embodiment. As shown in FIG. 1, a vehicle 900 includes a suspension system 100, a vehicle body 200, wheels 300, tires 310, a steering member 410, a steering shaft 420, a torque sensor 430, a steering angle sensor 440, a torque application section 460, a rack A pinion mechanism 470 , a rack shaft 480 , an engine 500 , an ECU (Electronic Control Unit) (control device) 600 , a power generator 700 and a battery 800 are provided.

A wheel 300 having a tire 310 mounted thereon is suspended from a vehicle body 200 by a suspension system 100 . Since vehicle 900 is a four-wheeled vehicle, four suspension devices 100, four wheels 300 and four tires 310 are provided.

The tires and wheels of the left front wheel, right front wheel, left rear wheel, and right rear wheel are respectively tire 310A and wheel 300A, tire 310B and wheel 300B, tire 310C and wheel 300C, and tire 310D and wheel. Also referred to as 300D. Hereinafter, likewise, the structures associated with the left front wheel, right front wheel, left rear wheel, and right rear wheel are represented by symbols "A", "B", "C", and "D". There is

Suspension system 100 includes a hydraulic shock absorber, an upper arm and a lower arm. The hydraulic damping device also includes a solenoid valve that adjusts the damping force generated by the hydraulic damping device. However, this does not limit the present embodiment, and the hydraulic shock absorber may use an electromagnetic valve other than the solenoid valve as the electromagnetic valve for adjusting the damping force. For example, as the electromagnetic valve, an electromagnetic valve using an electromagnetic fluid (magnetic fluid) may be provided.

A power generator 700 is attached to the engine 500 , and electric power generated by the power generator 700 is stored in the battery 800 . Further, the engine 500 is configured to be able to control the number of revolutions according to the vehicle speed control amount supplied from the ECU 600 .

A steering member 410 operated by a driver is connected to one end of a steering shaft 420 so as to transmit torque, and the other end of the steering shaft 420 is connected to a rack and pinion mechanism 470 .

Rack and pinion mechanism 470 is a mechanism for converting rotation of steering shaft 420 about its axis into displacement along the axial direction of rack shaft 480 . When the rack shaft 480 is axially displaced, the wheels 300A and 300B are steered via the tie rods and knuckle arms.

Torque sensor 430 detects the steering torque applied to steering shaft 420, in other words, the steering torque applied to steering member 410, and provides ECU 600 with a torque sensor signal indicating the detection result. More specifically, torque sensor 430 detects twisting of a torsion bar provided in steering shaft 420 and outputs the detection result as a torque sensor signal. As the torque sensor 430, a well-known sensor such as a Hall IC, MR element, or magnetostrictive torque sensor may be used.

The steering angle sensor 440 detects the steering angle of the steering member 410 and provides the detection result to the ECU 600 .

Torque applying section 460 applies assist torque or reaction torque to steering shaft 420 according to the steering control amount supplied from ECU 600 . Torque application unit 460 includes a motor that generates assist torque or reaction torque according to the steering control amount, and a torque transmission mechanism that transmits the torque generated by the motor to steering shaft 420 .

It should be noted that specific examples of the "controlled amount" in this specification include current value, duty ratio, damping rate, damping ratio, and the like.

The steering member 410, the steering shaft 420, the torque sensor 430, the steering angle sensor 440, the torque applying section 460, the rack and pinion mechanism 470, the rack shaft 480, and the ECU 600 constitute the steering device according to this embodiment.

In the above description, the term "torque-transmittable connection" refers to a connection in which rotation of one member causes rotation of the other member. is integrally molded, the other member is directly or indirectly fixed to one member, and the one member and the other member are interlocked via a joint member, etc. including at least the case where it is connected to

Further, in the above example, the steering device in which the steering member 410 to the rack shaft 480 are always mechanically connected is taken as an example, but this does not limit the present embodiment, and the steering apparatus according to the present embodiment is not limited to this. The device may be, for example, a steer-by-wire steering device. Matters described below in this specification can also be applied to a steer-by-wire steering system.

The vehicle 900 also includes a wheel speed sensor 320 provided for each wheel 300 for detecting the wheel speed of each wheel 300, a lateral G sensor 330 for detecting acceleration in the lateral direction of the vehicle 900, and detecting acceleration in the longitudinal direction of the vehicle 900. A front/rear G sensor 340, a yaw rate sensor 350 that detects the yaw rate of the vehicle 900, an engine torque sensor 510 that detects the torque generated by the engine 500, an engine speed sensor 520 that detects the speed of the engine 500, and a brake device. A brake pressure sensor 530 is provided to detect the pressure applied to the brake fluid. Information output from these various sensors is supplied to the ECU 600 via a CAN (Controller Area Network) 370 .

In addition, the vehicle 900 includes a GPS (Global Positioning System) sensor 550 that identifies the current position of the vehicle 900 and outputs current position information indicating the current position, and a purpose sensor that receives user input regarding a destination and indicates the destination. A user input reception unit 560 for outputting location information is also provided, and current position information and destination information are also supplied to ECU 600 via CAN 370 .

In addition, although not shown, the vehicle 900 includes an ABS (Antilock Brake System) which is a system for preventing wheel lock during braking, a TCS (Traction Control System) which suppresses wheel slippage during acceleration and the like, and It is equipped with a brake device capable of VSA (Vehicle Stability Assist) control, which is a vehicle behavior stabilization control system equipped with an automatic braking function for yaw moment control during cornering, a brake assist function, and the like.

Here, ABS, TCS, and VSA compare the wheel speed determined according to the estimated vehicle speed with the wheel speed detected by the wheel speed sensor 320, and the values of these two wheel speeds are the predetermined values. If there is a difference above, it is determined that the state is in the slip state. Through such processing, ABS, TCS, and VSA aim to stabilize the behavior of vehicle 900 by performing optimum brake control and traction control according to the running state of vehicle 900 .

A braking device provided in vehicle 900 is configured to perform a braking operation according to a vehicle speed control amount supplied from ECU 600 .

ECU 600 centrally controls various electronic devices provided in vehicle 900 . For example, the ECU 600 controls the magnitude of the assist torque or the reaction torque applied to the steering shaft 420 by adjusting the steering control amount supplied to the torque applying section 460 .

In addition, ECU 600 controls opening and closing of a solenoid valve provided in a hydraulic shock absorber included in suspension system 100 by supplying a suspension control amount to the solenoid valve. In order to enable this control, a power line is provided for supplying drive power from the ECU 600 to the solenoid valve.

(ECU 600)
In the following, the ECU 600 will be specifically described with reference to different drawings. FIG. 2 is a diagram showing a schematic configuration of the ECU 600. As shown in FIG.

As shown in FIG. 2, the ECU 600 includes a steering control section 630, a suspension control section 650, and a vehicle speed control section 670.

Steering control unit 630 refers to various sensor detection results included in CAN 370 to set steering control amounts for vehicle 900 to travel along the lane. Steering control unit 630 supplies the set steering control amount to torque applying unit 460 . Steering control unit 630 also supplies the set steering control amount to at least one of suspension control unit 650 and vehicle speed control unit 670 . Instead of the set steering control amount, steering control unit 630 calculates the amount of deviation of vehicle 900 from the center of the lane and the curvature R4 to be traced by steering control unit 630 at least in suspension control unit 650 and vehicle speed control unit 670. It may be configured to supply to any one. The "deviation amount of the vehicle 900 from the center of the lane" and the "curvature R4 to be traced" will be described later.

In this specification, the expression "with reference to" may include meanings such as "using", "considering", and "depending on".

The suspension control unit 650 refers to at least one of the detection results of various sensors included in the CAN 370, the steering control amount supplied from the steering control unit 630, the deviation amount of the vehicle 900 from the center of the lane, and the curvature R4 to be traced. Then, the magnitude of the suspension control amount to be supplied to the solenoid valve provided in the hydraulic damping device included in the suspension system 100 is determined.

The vehicle speed control unit 670 refers to at least one of the detection results of various sensors included in the CAN 370, the steering control amount supplied from the steering control unit 630, the deviation amount of the vehicle 900 from the center of the lane, and the curvature R4 to be traced. Then, the magnitude of the vehicle speed control amount to be supplied to the engine 500 and the brake device is determined.

Note that the steering control unit 630, the suspension control unit 650, and the vehicle speed control unit 670 may be implemented as separate ECUs. In such a configuration, steering control unit 630, suspension control unit 650, and vehicle speed control unit 670 communicate with each other using communication means, thereby realizing the control described in this specification.

(Steering control unit)
Subsequently, the steering control unit 630 (the steering control device in the claims) will be described in more detail with reference to FIG. FIG. 3 is a block diagram showing the configuration of steering control section 630. As shown in FIG. As shown in FIG. 3, the steering control unit 630 includes a captured image acquisition unit 11, a vehicle speed information acquisition unit 12, a map GPS information acquisition unit 13, a first target control amount calculation unit 14, a second target control amount calculation unit. 15, gain calculator 16, multipliers 17 and 18, adder 19 (third target control amount calculator in claims), subtractor 20 (fourth target control amount calculator in claims) , and a motor command current calculator 21 . Steering control unit 630 calculates a steering control amount for controlling the steering of vehicle 900 .

The captured image acquisition unit 11 acquires a captured image of an imaging range including the front of the vehicle 900 included in the CAN 370 . The captured image acquisition unit 11 supplies the acquired captured images to the first target control amount calculation unit 14 and the second target control amount calculation unit 15 .

Vehicle speed information acquisition unit 12 acquires vehicle speed information indicating the vehicle speed of vehicle 900 included in CAN 370 . The vehicle speed information acquisition unit 12 supplies the acquired vehicle speed information to the first target control amount calculation unit 14 , the second target control amount calculation unit 15 , and the gain calculation unit 16 .

The map GPS information acquisition unit 13 acquires map information and GPS information included in the CAN 370 . The map GPS information acquisition unit 13 supplies the acquired map information and GPS information to the second target control amount calculation unit 15 . Note that the map-GPS information acquisition unit 13 may be configured to acquire map information and GPS information, respectively, or may be configured to acquire map information including GPS information. Here, the "GPS information" is information indicating the position of the vehicle 900 on the earth, and is, for example, information indicated by the latitude and longitude coordinates of the vehicle 900 at each point in time.

The first target control amount calculation unit 14 refers to the captured image acquired from the captured image acquisition unit 11 and the vehicle speed information acquired from the vehicle speed information acquisition unit 12, and performs steering control for the vehicle 900 to travel along the lane. A first target control amount, which is a control amount, is calculated. Specifically, the first target control amount calculation unit 14 refers to the captured image acquired from the captured image acquisition unit 11, calculates the position of the lane in the vertical direction, and calculates the deviation amount of the vehicle 900 from the center of the lane. Calculate More specifically, the first target control amount calculation unit 14 identifies lane markings such as a roadway outer line and a roadway center line on the road included in the captured image acquired from the captured image acquisition unit 11 by image analysis. do. Subsequently, the first target control amount calculation unit 14 refers to the inclination and position of the identified lane marking on the captured image to determine the position of the vehicle 900 on the road and the center of the lane on the road. Identify location. Subsequently, the first target control amount calculation unit 14 compares the specified position of the vehicle 900 and the position of the center of the lane, thereby calculating the amount of deviation of the position of the vehicle 900 from the center of the lane. In this specification, the term "vertical direction of the lane" refers to the direction perpendicular to the traveling direction of the lane, and the term "displacement amount" refers to the displacement of the vehicle position in the direction perpendicular to the lane.

Subsequently, the first target control amount calculator 14 refers to the calculated deviation amount and the acquired vehicle speed information to calculate the first target control amount. Note that the first target control amount calculator 14 may be configured to calculate the first target control amount by referring only to the calculated deviation amount. The first target control amount calculator 14 supplies the calculated first target control amount to the multiplier 17 . The first target control amount calculator 14 also supplies the calculated deviation amount to the gain calculator 16 . Here, the first target control amount calculated by the first target control amount calculating section is used as a control amount to be referred to, for example, when feedback control is performed.

The second target control amount calculation unit 15 refers to at least one of the map information and the GPS information acquired from the map GPS information acquisition unit 13 to specify the position of the vehicle 900 on the map indicated by the map information. Subsequently, the second target control amount calculation unit 15 refers to the identified position of the vehicle 900 and the map information to acquire the shape of the road in the traveling direction of the vehicle 900 . Here, the "shape of the road" includes, for example, a straight road, a curved road, and the like. The second target control amount calculation unit 15 calculates a route to be traced by the vehicle 900 by referring to the lane center position calculated from the obtained shape of the road in the traveling direction. The second target control amount calculator 15 calculates the curvature to be traced from the calculated route to be traced by the vehicle 900 . In this way, the second target control amount calculation unit 15 refers to the map information and the GPS information acquired from the map GPS information acquisition unit 13 to determine the curvature to be traced by the vehicle 900, that is, the curvature to be traveled by the vehicle 900. Calculate the curvature. Subsequently, the second target control amount calculator 15 calculates a second target control amount, which is a steering control amount for tracing the calculated curvature. Here, the second target control amount calculated by the second target control amount calculating section is used as a control amount to be referred to, for example, when performing feedforward control. The second target control amount calculation unit 15 refers to at least one of the captured image acquired from the captured image acquisition unit 11 and the vehicle speed information acquired from the vehicle speed information acquisition unit 12 in addition to the map information and the GPS information. The configuration may be such that the curvature to be traced is calculated. More specifically, the second target control amount calculation unit 15 identifies the position of the vehicle 900 on the road by referring to the acquired captured image, and identifies by referring to GPS information and map information. The position of the vehicle 900 on the map is corrected. In addition, the second target control amount calculation unit 15 identifies the lane center position in the traveling direction of the vehicle 900 by referring to the acquired captured image, and identifies the vehicle by referring to the GPS information and the map information. The lane center position in the traveling direction of 900 is corrected. Subsequently, the second target control amount calculator 15 supplies the calculated second target control amount to the multiplier 18 . A method of calculating the "curvature to be traced" will be described later. Further, the calculation process with reference to the vehicle speed information will be described later in different embodiments.

The gain calculation unit 16 refers to the deviation amount acquired from the first target control amount calculation unit 14, and calculates a first gain by which the first target control amount is multiplied and a second gain by which the second target control amount is multiplied. and Here, in FIG. 3, the first gain is indicated by 1-α and the second gain is indicated by α. The sum of the first gain and the second gain is 1, and α decreases as the deviation amount of vehicle 900 from the lane center increases. In other words, as the deviation amount of vehicle 900 from the lane center increases, the ratio of the first gain to the sum of the first gain and the second gain increases, and the ratio of the second gain decreases. The gain calculator 16 supplies the calculated first gain to the multiplier 17 and supplies the calculated second gain to the multiplier 18 .

The multiplication unit 17 multiplies the first target control amount obtained from the first target control amount calculation unit 14 and the first gain obtained from the gain calculation unit 16, and supplies the calculation result to the addition unit 19. .

The multiplication unit 18 multiplies the second target control amount obtained from the second target control amount calculation unit 15 and the second gain obtained from the gain calculation unit 16, and supplies the calculation result to the addition unit 19. .

The addition unit 19 adds the first target control amount multiplied by the first gain acquired from the multiplication unit 17 and the second target control amount multiplied by the second gain acquired from the multiplication unit 18. Then, the first target steering control amount (the third target control amount in the claims) is calculated. The adding section 19 supplies the calculated first target steering control amount to the subtracting section 20 . Here, the "first target steering control amount" indicates a steering control amount necessary to control the steering member 410 to a desired steering angle when the vehicle 900 is caused to travel along the lane.

Subtraction unit 20 acquires information indicating the actual rack stroke of vehicle 900 included in CAN 370 . Information indicating the actual rack stroke includes, for example, steering angle information of the steering member 410 acquired from the steering angle sensor 440 . The subtraction unit 20 obtains a second target steering control amount (claim 4th target control amount in) is calculated. The subtraction unit 20 supplies the calculated second target steering control amount to the motor instruction current calculation unit 21 . Here, the "second target steering control amount" indicates a steering control amount required to control the current steering angle of the steering member 410 to the desired steering angle of the steering member 410 described above.

The motor instruction current calculation unit 21 refers to the second target steering control amount acquired from the subtraction unit 20 to calculate the third target steering control amount. As an example, the motor instruction current calculation section 21 includes a proportional gain multiplication section, an integration section, an integral gain multiplication section, and an addition section. The motor instruction current calculator 21 supplies the second target steering control amount obtained from the subtractor 20 to the proportional gain multiplier and the integrator. The proportional gain multiplication section multiplies the second target steering control amount supplied from the subtraction section 20 by a predetermined gain, and supplies the calculation result to the addition section. The integrating section integrates the second target steering control amount supplied from the subtracting section 20 and supplies the calculation result to the integral gain multiplying section. The integral gain multiplying section multiplies the integrated second target steering control amount by a predetermined gain, and supplies the calculation result to the adding section. The addition section calculates a third target steering control amount by adding the calculation result supplied from the proportional gain multiplication section and the calculation result supplied from the integral gain multiplication section. The motor instruction current calculator 21 supplies the third target steering control amount calculated as described above to the steering controller 630 . Here, the predetermined gain is an arbitrarily set fixed value.

The configuration of the motor command current calculation unit 21 described above is an example of the configuration of the motor command current calculation unit 21 in this embodiment, and does not limit this embodiment. The motor instruction current calculator 21 in this embodiment includes, for example, a first proportional gain multiplier, a subtractor, a second proportional gain multiplier, an integrator, an integral gain multiplier, and an adder. good too. In this configuration, the motor instruction current calculator 21 supplies the second target steering control amount acquired from the subtractor 20 to the first proportional gain multiplier. The first proportional gain multiplication section multiplies the second second target steering control amount supplied from the subtraction section 20 by a predetermined gain, and supplies the calculation result to the subtraction section. The subtraction unit acquires the motor angular velocity of vehicle 900 included in CAN 370 . Information indicating the motor angular velocity includes, for example, steering angle information of the steering member 410 acquired from the steering angle sensor 440 . The subtraction section subtracts the motor angular velocity from the calculation result by the first proportional gain multiplication section and supplies the calculation result to the second proportional gain multiplication section and the integration section. The second proportional gain multiplication section multiplies the calculation result supplied from the subtraction section by a predetermined gain, and supplies the calculation result to the addition section. The integrating section integrates the calculation result supplied from the subtracting section and supplies the integrated result to the integral gain multiplying section. The integral gain multiplying section multiplies the result of integration by the integrating section by a predetermined gain, and supplies the calculation result to the adding section. The addition section calculates a third target steering control amount by adding the calculation results supplied from the second proportional gain multiplication section and the integral gain multiplication section. The motor instruction current calculator 21 supplies the third target steering control amount calculated as described above to the steering controller 630 . Here, the predetermined gain is an arbitrarily set fixed value.

The steering control unit 630 according to the present embodiment refers to the first target control amount, the second target control amount, the first gain, and the second gain to calculate the steering control amount. , the amount of deviation of the vehicle 900 can be kept within the allowable error, and smoother vehicle control can be performed.

(Specific example of calculation processing of curvature to be traced)
Below, the calculation processing of the curvature to be traced by the second target control amount calculation section 15 provided in the steering control section 630 will be described in more detail with reference to FIGS. 4 to 6. FIG. 4 to 6 are schematic diagrams for explaining the calculation processing of the curvature to be traced.

First, the second target control amount calculator 15 sets a representative point A of the vehicle 900 as shown in FIG. The position of the representative point A of the vehicle 900 may be any point that indicates the position of the vehicle 900 . For example, the center of gravity of the vehicle 900 may be the representative point of the vehicle 900 .

Subsequently, the second target control amount calculator 15 sets a plurality of reference points. The second target control amount calculator 15 sets at least three reference points. It is preferable that the number of reference points set by the second target control amount calculator 15 is three. As a result, the processing load on the second target control amount calculator 15 can be reduced. The calculation process of the curvature to be traced when there are three reference points will be described below.

The second target control amount calculation unit 15 sets a reference point at a lane center position a predetermined distance away from the representative point A of the vehicle 900 . For example, as shown in FIG. 4 , the second target control amount calculator 15 sets the reference point B at the center of the lane, which is a straight line distance L1 from the representative point A of the vehicle 900 . Further, the second target control amount calculation unit 15 sets the reference point C at the lane center position which is separated from the representative point A of the vehicle 900 by the straight line distance L2. Further, the second target control amount calculation unit 15 sets the reference point D at the lane center position which is separated from the representative point A of the vehicle 900 by the distance L3 in the straight line. Here, the predetermined distance is an arbitrarily set fixed value. As described above, the second target control amount calculation unit 15 obtains the map information and the GPS information obtained from the map GPS information obtaining unit 13. Based on the shape of the road in the traveling direction of the vehicle 900, The lane center position in the traveling direction of the vehicle 900 may be set, or the lane center position in the traveling direction of the vehicle 900 may be set by referring to the captured image acquired from the captured image acquisition unit 11. good.

Subsequently, as shown in FIG. 5, the second target control amount calculator 15 sets a plurality of curves passing through the representative point A of the vehicle 900 and arbitrary two points among the plurality of reference points. More specifically, the second target control amount calculator 15 sets a circular curve passing through the representative point A of the vehicle 900 and the reference points B and C. As shown in FIG. Further, the second target control amount calculation unit 15 sets a curve of a circle passing through the representative point A of the vehicle 900 and the reference points C and D. As shown in FIG. Further, the second target control amount calculation unit 15 sets a curve of a circle passing through the representative point A of the vehicle 900 and the reference points B and D. The second target control amount calculator 15 calculates the curvatures R1 to R3 of each of the set curves.

Subsequently, as shown in FIG. 6, the second target control amount calculator 15 calculates the curvature R4 to be traced by averaging the curvatures R1 to R3 of the plurality of set curves. The steering control unit 630 according to this embodiment can perform smoother vehicle control by referring to the second target control amount calculated based on the average value of the curvatures of a plurality of curves.

In the present embodiment, the configuration for calculating the curvature to be traced by setting three reference points set by the second target control amount calculating unit 15 has been described, but this does not limit the present embodiment. The second target control amount calculator 15 according to the present embodiment may be configured to set three or more reference points and calculate the curvature R4 to be traced.

(Flow of Steering Control Amount Calculation Processing)
An example of the flow of steering control amount calculation processing executed by the steering control unit 630 according to this embodiment will be described below with reference to FIG. 7 . FIG. 7 is a flowchart showing an example of the flow of steering control amount calculation processing by the steering control unit 630. As shown in FIG.

The steering control unit 630 according to the present embodiment calculates the steering control amount necessary for the vehicle 900 to travel along the lane by executing steps S11 to S19 described below. In the flow of the steering control amount calculation process below, a case where the reference points set by the second target control amount calculation unit 15 are three will be described as an example.

(Step S11)
First, in step S11, the second target control amount calculation unit 15 refers to at least one of the map information and the GPS information included in the CAN 370 acquired via the map GPS information acquisition unit 13, and Reference points BD are set at a predetermined distance from the representative point A of . Here, the second target control amount calculation unit 15 calculates at least the captured image included in the CAN 370 acquired via the captured image acquisition unit 11 and the vehicle speed information included in the CAN 370 acquired via the vehicle speed information acquisition unit 12. A reference point may be set by further referring to any of them.

(Step S12)
Next, in step S12, the second target control amount calculator 15 sets a plurality of curves passing through the representative point A of the vehicle 900 and any two of the set reference points BD.

(Step S13)
Subsequently, in step S13, the second target control amount calculator 15 calculates curvatures R1 to R3 of each of the plurality of set curves.

(Step S14)
Subsequently, in step S14, the second target control amount calculator 15 calculates the average value of the curvatures R1 to R3 of the plurality of curves as the curvature R4 that the vehicle 900 should trace.

(Step S15)
Subsequently, in step S15, the second target control amount calculator 15 refers to the calculated curvature R4 to be traced to calculate a second target control amount.

(Step S16)
Subsequently, in step S16, the first target control amount calculation unit 14 refers to the captured image included in the CAN 370 acquired via the captured image acquisition unit 11, and calculates the deviation amount of the vehicle 900 from the center of the lane. do.

(Step S17)
Subsequently, in step S17, the first target control amount calculation unit 14 refers to the calculated deviation amount and the vehicle speed information included in the CAN 370 acquired via the vehicle speed information acquisition unit 12, and calculates the first target control amount. Calculate the amount of control.

(Step S18)
Subsequently, in step S18, the gain calculation unit 16 refers to the deviation amount acquired from the first target control amount calculation unit 14 and the vehicle speed information included in the CAN 370 acquired via the vehicle speed information acquisition unit 12. , a first gain by which the first target control amount is multiplied, and a second gain by which the second target control amount is multiplied.

(Step S19)
Subsequently, in step S<b>19 , the multiplication unit 17 multiplies the first target control amount obtained from the first target control amount calculation unit 14 and the first gain obtained from the gain calculation unit 16 . Subsequently, the multiplication unit 18 multiplies the second target control amount obtained from the second target control amount calculation unit 15 and the second gain obtained from the gain calculation unit 16 . Subsequently, the adding unit 19 adds the first target control amount multiplied by the first gain acquired from the multiplication unit 17 and the second target control amount multiplied by the second gain acquired from the multiplication unit 18. is added to calculate the first target steering control amount. Subsequently, the subtraction unit 20 calculates the second target steering control amount by taking the difference between the first target steering control amount acquired from the addition unit 19 and the information indicating the actual rack stroke acquired from the CAN 370. . Subtraction unit 20 outputs the calculated second target steering control amount as the steering control amount required to control steering member 410 .

In the flow of the steering control amount calculation process described above, the steering control unit 630 performs the first target control amount calculation process of steps S16 to S17 after the second target control amount calculation process of steps S11 to S15. However, the steering control unit 630 according to the present embodiment may be configured to perform the first target control amount calculation process before the second target control amount calculation process. Alternatively, the second target controlled variable and the first target controlled variable may be calculated at the same time.

[Embodiment 2]
Embodiment 2 of the present invention will be described in detail below. In the following description, descriptions of matters that have already been described in the above embodiment will be omitted, and differences from the above embodiment will be described.

The second target control amount calculator 15 according to the present embodiment calculates the curvature R4 to be traced by taking the weighted average of the curvatures of the plurality of set curves. More specifically, the second target control amount calculating unit 15 sets a larger weighting factor to be multiplied by the curve passing through the reference point closer to the vehicle 900 among the plurality of set curves. , compute the curvature to be traced by taking a weighted average of the curvatures of multiple curves.

A method of calculating a weighted average when there are three reference points will be described below with reference to FIG. In the following, a method of calculating the weighted average when the straight-line distances from the representative point A to the reference points B to D are 10 m, 20 m, and 30 m, respectively, will be described.

The curvature R1 is the curvature of the curve passing through the representative point A and the reference points B and C, and the total value of the straight line distances from the representative point A to the reference points B and C is 30 m. The curvature R2 is the curvature of the curve passing through the representative point A and the reference points C and D, and the total straight line distance from the representative point A to the reference points C and D is 50 m. The curvature R3 is the curvature of the curve passing through the representative point A and the reference points B and D, and the total value of the straight line distances from the representative point A to the reference points B and D is 40 m. Here, in the present embodiment, since the weighting factor to be multiplied by the curve passing through the reference point closer to the vehicle 900 is set larger, the total value of the straight-line distances from the representative point A to the reference point and the weighting factor are set to be larger. A curvature R4 is calculated by setting weighting coefficients of the curvatures R1 to R3 so as to have a negative correlation. As an example, the curvature R4 to be traced is calculated based on the following formula.

Curvature R4 = 50/120 x R1 + 30/120 x R2 + 40/120 x R3
The steering control unit 630 according to the present embodiment can perform smoother vehicle control along the lane by setting a larger weighting factor to be multiplied by the curve passing through the reference point closer to the vehicle 900. .

In the present embodiment, the configuration for calculating the curvature to be traced by setting three reference points set by the second target control amount calculating unit 15 has been described, but this does not limit the present embodiment. The second target control amount calculator 15 according to the present embodiment may be configured to set three or more reference points and calculate the curvature R4 to be traced.

[Embodiment 3]
Embodiment 3 of the present invention will be described in detail below. In the following description, description of matters already described in the second embodiment will be omitted, and differences from the second embodiment will be described.

The second target control amount calculation unit 15 according to the present embodiment refers to the vehicle speed information acquired from the vehicle speed information acquisition unit 12, calculates a predetermined distance from the representative point A of the vehicle 900 to a plurality of reference points, Set multiple reference points. More specifically, the second target control amount calculator 15 refers to the vehicle speed information acquired from the vehicle speed information acquirer 12 and calculates the distance that the vehicle 900 reaches after a predetermined time has passed. The second target control amount calculator 15 sets the calculated distances as predetermined distances from the representative point A of the vehicle 900 to the plurality of reference points. That is, the second target control amount calculation unit 15 sets the distances from the representative point of the vehicle 900 to the plurality of reference points longer as the vehicle speed of the vehicle 900 increases. Here, the predetermined time is an arbitrarily set time.

The steering control unit 630 according to this embodiment can perform smoother vehicle control according to the vehicle speed of the vehicle 900 by setting a plurality of reference points according to the vehicle speed of the vehicle 900 .

[Example of realization by software]
The control blocks (steering control unit 630, suspension control unit 650, vehicle speed control unit 670) of the ECU 600 may be implemented by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be implemented by a CPU (Central It may be realized by software using a processing unit).

In the latter case, the ECU 600 includes a CPU that executes instructions of a program, which is software that implements each function, and a ROM (Read Only Memory) or storage device that stores the program and various data so that they can be read by a computer (or CPU). (these are referred to as “recording media”), RAM (Random Access Memory) for developing the above programs, and the like. The object of the present invention is achieved by a computer (or CPU) reading and executing the program from the recording medium. As the recording medium, a "non-temporary tangible medium" such as a tape, disk, card, semiconductor memory, programmable logic circuit, or the like can be used. Also, the program may be supplied to the computer via any transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that the present invention can also be implemented in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

11 captured image acquisition unit 12 vehicle speed information acquisition unit 13 map GPS information acquisition unit 14 first target control amount calculation unit 15 second target control amount calculation unit 16 gain calculation unit 19 addition unit (third target control amount calculation unit )
20 subtraction unit (fourth target control amount calculation unit)
630 steering control unit (steering control device)
900 vehicle

Claims (5)

In a steering control device that calculates a steering control amount for controlling steering of a vehicle,
a captured image acquisition unit that acquires a captured image of an imaging range including the front of the vehicle;
a vehicle speed information acquisition unit that acquires vehicle speed information indicating the vehicle speed of the vehicle;
a map GPS information acquisition unit that acquires map information and GPS information;
a first target control amount calculation unit that calculates a first target control amount by referring to the captured image acquired by the captured image acquisition unit and the vehicle speed information acquired by the vehicle speed information acquisition unit;
referring to the map information and GPS information acquired by the map GPS information acquiring unit, acquiring the shape of the road in the traveling direction of the vehicle, calculating a route to be traced based on the shape of the road, and performing the tracing; a second target control amount calculation unit that calculates a curvature to be traced based on the path to be traced and calculates a second target control amount based on the curvature to be traced;
a gain calculation unit that calculates a first gain by which the first target control amount is multiplied, and a second gain by which the second target control amount is multiplied,
Steering control for calculating a controlled variable for controlling the steering based on the first target controlled variable multiplied by the first gain and a second target controlled variable multiplied by the second gain. Device. The first target control amount calculation unit refers to the captured image acquired by the captured image acquisition unit to calculate the amount of deviation of the vehicle from the center of the lane,
The steering control device according to claim 1, wherein the gain calculator calculates the first gain and the second gain by referring to the deviation amount calculated by the first target control amount. A third target control amount is calculated by adding the first target control amount multiplied by the first gain and the second target control amount multiplied by the second gain. a third target control amount calculation unit;
A fourth target control amount calculation for calculating a fourth target control amount by obtaining a difference between a desired steering angle at which the steering is controlled by the third target control amount and an actual steering angle of the steering. Department and
The steering control device according to claim 1 or 2, further comprising: A steering device comprising the steering control device according to any one of claims 1 to 3 . A vehicle comprising the steering control device according to any one of claims 1 to 4 .

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