JP2021142889A - Automatic steering control apparatus, automatic steering control method, and automatic steering program - Google Patents

Abstract

To provide an automatic steering control apparatus, an automatic steering control method, and an automatic steering program, which are capable of improving a trackability to a target locus.SOLUTION: An apparatus includes: a feedback control part 206 for calculating a feedback control amount δFB on the basis of an azimuth measurement value being a measurement value of an azimuth and an azimuth target value for traveling on a target locus; a feedforward control part 207 for calculating a feedforward control amount δFF for correcting a deviation of the feedback control amount δFB by using a motion model in the case of traveling so that a center of gravity of a vehicle 100 goes through the target locus, and calculating a post-compensation feedforward control amount δFF_C that is compensated for an influence of a lateral deviation amount from the target locus of the vehicle 100; and a steering control part 208 for performing steering control on the basis of the feedback control amount and feedforward control amount.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to an automatic steering control device, an automatic steering control method, and an automatic steering program capable of automatically steering a vehicle.

Technology has been developed to automatically drive the vehicle along the target trajectory. In order to automatically drive the vehicle so that it does not deviate from the road or lane, it is necessary to set the steering angle according to the road or lane.

In automatic steering control for automatic driving, it is common practice to use feedforward control and feedback control together. Feedforward control is a control that sets the steering angle in advance (before automatic follow-up driving is performed) so that the vehicle does not deviate from the traveling direction based on the road curvature, the cross slope (the slope in the direction perpendicular to the road route), and the like. Is. The feedback control is a control that measures the amount of the vehicle currently deviating from the target trajectory after the start of the automatic follow-up running, and sets the steering angle so as to eliminate this deviation.

For example, in Patent Document 1, the lane shape such as the lane curvature of the target course, the amount of deviation between the target course and the own vehicle traveling path in the vehicle width direction, the yaw angle deviation of the own vehicle traveling path with respect to the target course, and the like are detected. Disclosed is a technique for performing feedforward control and feedback control based on a value to perform lane keep control for traveling along a set target course and deviation prevention control for preventing deviation from the lane.

Japanese Unexamined Patent Publication No. 2017-171225

In order to drive the vehicle appropriately and automatically, the distance from the center of the lane or the target track to the center of the vehicle, the curvature of the road, the amount of change in curvature, the vehicle speed, the cross slope (inclination in the direction perpendicular to the route direction of the road), etc. It is necessary to calculate the steering angle at any time using various parameters.

Each parameter used for steering control is obtained by, for example, an image captured by a camera, a sensor, or the like, but an error may occur when the parameter is acquired. When the parameters include an error in this way, the steering angle calculated based on the parameters including the error may not be the steering angle for driving the vehicle along the target trajectory. Therefore, even if the parameters include an error, it is required to improve the follow-up performance with respect to the target trajectory.

In view of such circumstances, it is an object of the present disclosure to provide an automatic steering control device, an automatic steering control method, and an automatic steering program capable of further improving the followability to a target trajectory.

The automatic steering control device according to one aspect of the present disclosure is an automatic steering control device that automatically controls the steering angle of the vehicle so that the vehicle follows a target trajectory, and is a measured value of the azimuth angle of the vehicle. Based on the azimuth angle measurement value and the azimuth angle target value for traveling on the target trajectory, the feedback control amount which is the steering angle for correcting the deviation between the azimuth angle measurement value and the azimuth angle target value is calculated. The feedforward control amount for correcting the deviation of the feedback control amount is calculated by using the feedback control unit and the motion model when the center of gravity of the vehicle travels along the target track, and the calculated feedforward is calculated. A feedforward control unit that calculates a compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target track using the control amount, and the feedback control amount and the compensated feedforward control. It includes a steering control unit that performs steering control based on the amount.

The automatic steering control method according to one aspect of the present disclosure is an automatic steering control method that automatically controls the steering angle of the vehicle so that the vehicle follows a target trajectory, and is a measured value of the azimuth angle of the vehicle. Based on the azimuth angle measurement value and the azimuth angle target value for traveling on the target trajectory, the feedback control amount which is the steering angle for correcting the deviation between the azimuth angle measurement value and the azimuth angle target value is calculated. , The feedforward control amount for correcting the deviation of the feedback control amount is calculated by using the motion model when the center of gravity of the vehicle travels along the target track, and the calculated feedforward control amount is used. Therefore, a compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target track is calculated, and steering control is performed based on the feedback control amount and the compensated feedforward control amount.

The automatic steering control program according to one aspect of the present disclosure is an automatic steering control program that automatically controls the steering angle of the vehicle so that the vehicle follows a target trajectory, and is a measured value of the azimuth angle of the vehicle. Based on the azimuth angle measurement value and the azimuth angle target value for traveling on the target trajectory, the feedback control amount which is the steering angle for correcting the deviation between the azimuth angle measurement value and the azimuth angle target value is calculated. The procedure, the procedure for calculating the feedforward control amount for correcting the deviation of the feedback control amount using the motion model when the center of gravity of the vehicle travels along the target trajectory, and the calculated feedforward. Based on the procedure for calculating the compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target track using the control amount, and the feedback control amount and the compensated feedforward control amount. The procedure for performing steering control and the procedure for performing steering control are performed by the processor of the vehicle.

According to the present disclosure, it is possible to perform automatic steering control with higher followability to a target trajectory.

The figure for demonstrating the vehicle equipped with the automatic steering control device of embodiment of this disclosure. Functional block diagram of the automatic steering control unit Block diagram for explaining an example of the processing flow of the steering amount calculation unit Diagram for explaining a two-wheeled model The figure for demonstrating the property which each term of the formula (7) has. A flowchart showing the calculation process of the compensation values K _i1 , _{Ki 2} , and _{Ki 3.} A flowchart showing the calculation process of the compensation values K _i1 , _{Ki 2} , and _{Ki 3.} A flowchart showing the calculation process of the compensation values K _i1 , _{Ki 2} , and _{Ki 3.}

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples, and the present disclosure is not limited to these embodiments.

FIG. 1 is a diagram for explaining a vehicle 100 equipped with the automatic steering control device 200 according to the embodiment of the present disclosure. In the embodiment of the present disclosure, as shown in FIG. 1, the vehicle 100 is a commercial vehicle such as a truck.

The vehicle 100 has a cab 101, a loading platform 102, front wheels 103, and rear wheels 104. The cab 101 is provided with a camera 105, which will be described later. The camera 105 is provided at a substantially front end portion of the vehicle 100 and at a position where the front of the vehicle 100 can be seen. More specifically, the camera 105 is provided between the windshield and the dashboard, between the windshield and the rear-view mirror, and the like in the driver's seat in the cab 101.

The front wheel 103 is configured to face a predetermined steering angle. The steering angle (actual steering angle) of the front wheels 103 is automatically controlled according to the shape of the road or lane on which the vehicle 100 travels while the automatic steering control device 200 described later is operating. .. As a result, the vehicle 100 can automatically follow the road or lane.

FIG. 2 is a functional block diagram of the automatic steering control device 200. As shown in FIG. 2, the automatic steering control device 200 includes a lateral position information generation unit 201, an azimuth measurement value information generation unit 202, a road shape information generation unit 203, a vehicle speed sensor 204, and a steering amount calculation unit 205. And a steering control unit 208. The steering amount calculation unit 205 includes a feedback control unit 206 and a feedforward control unit 207.

The lateral position information generation unit 201 generates lateral position information regarding the lateral position of the vehicle 100 based on an image in front of the vehicle 100 (hereinafter, referred to as a front image) taken by the camera 105. The image in front of the vehicle 100 is an image of a road, a lane, another vehicle, or the like existing in front of the vehicle as seen from the camera 105. The lateral position information is information indicating the position of the center of the vehicle 100 as seen from the target track in the lateral direction (width direction) of the road and the vehicle 100. The target track is a target track when the vehicle 100 travels by automatic follow-up running. The target track is set at any time based on, for example, the road shape in front of the vehicle, map information, information on the destination, and the like. When the vehicle 100 automatically follows along the road, the target track is, for example, a line along the center of the road. Further, when the vehicle 100 changes lanes, for example, the target track is a line that gently connects the centers of the lanes, for example.

The azimuth measurement value information generation unit 202 generates azimuth measurement value information indicating the measurement value of the azimuth angle of the vehicle 100 as seen from the camera 105 based on the front image. The azimuth angle is an angle formed by the direction of the vehicle 100 and the tangential direction of the target track when the vehicle 100 is viewed from above, and is an angle with the position of the camera 105 as the apex. The measured value of the azimuth angle means a value measured based on the front image. The measured value of the azimuth is the measured value of the azimuth seen from the camera 105 located at the front end of the vehicle 100 when the vehicle 100 is viewed from above.

The road shape information generation unit 203 generates various road shape information regarding the road shape based on the front image. In the present embodiment, the road shape information includes at least one of curvature information, curvature change amount information, and cross slope information. The curvature information is information regarding the curvature of the target track in front of the vehicle 100. The curvature change amount information is information on the curvature change amount in the target trajectory. The cross slope information is information about the cross slope which is the lateral slope of the road. The method by which the road shape information generation unit 203 generates curvature information, curvature change amount information, or cross slope information from the front image is not particularly limited in the present disclosure.

The vehicle speed sensor 204 is a sensor that detects the traveling speed of the vehicle 100 (hereinafter referred to as the vehicle speed), and generates vehicle speed information related to the vehicle speed.

The steering amount calculation unit 205 calculates the steering amount for automatically following the vehicle 100 along the target track based on the road shape information and the vehicle speed information. The steering amount calculation unit 205 has a processor and a storage unit that stores the program, and the processor develops and executes the program from the storage unit to execute the operation of the steering amount calculation unit 205.

As shown in FIGS. 2 and 3, the steering amount calculation unit 205 includes a feedback control unit 206 and a feedforward control unit 207. Details of the feedback control unit 206 and the feedforward control unit 207 will be described later.

The steering amount calculation unit 205 is based on the feedback control amount δ _{FB at a certain time point T1 calculated by the feedback control unit 206 and the feedforward control amount δ FF_C} calculated by the feedforward control unit 207 at the time point T1. The steering amount at the time point T1 is determined.

The steering control unit 208 performs automatic steering control of the front wheels 103 based on the steering amount calculated as described above. By repeating such processing by the automatic steering control device 200 in a minute time, the vehicle 100 can automatically follow the target track.

<Feedback control unit 206>
Hereinafter, the feedback control unit 206 included in the steering amount calculation unit 205 will be described. The feedback control unit 206 uses feedback control to control the steering angle for eliminating (correcting) the deviation of the lateral position and azimuth angle measurement values of the vehicle 100 at a certain time point T1 from the lateral position target value and the azimuth angle target value. calculate. In the present disclosure, the steering angle calculated by the feedback control unit 206 is referred to as the feedback control amount δ _FB .

FIG. 3 is a block diagram for explaining an example of the processing flow of the steering amount calculation unit 205.

As shown in FIG. 3, when the lateral position information, the azimuth measurement value information, and the respective target values are input as the parameters for the feedback control, the feedback control unit 206 uses the forward gaze model to obtain the lateral position and the azimuth. _{The feedback control amount δ FB} for eliminating the deviation of the angle measurement value from each target value is calculated. The target values of the lateral position and the azimuth angle are appropriately set based on, for example, the front image.

The forward gaze model is a model for calculating a steering angle that eliminates the deviation in the front by the distance L when it is assumed that the driver is gaze forward by the distance L.

The proportional gain K _p and the differential gain (differential time) K _d used for feedback control may be set to constant values in advance by simulation or the like, or are set to variables that appropriately change according to, for example, vehicle speed. May be good.

<Feedforward control unit 207>
Next, the feedforward control unit 207 included in the steering amount calculation unit 205 will be described. The feedforward control unit 207 uses a motion model that assumes a slip angle (slip angle) of the vehicle 100 when the vehicle 100 travels so that the center of gravity passes through the target trajectory, and steers according to the shape of the road on which the vehicle 100 travels. The first steering angle component that corrects the influence on the angle is calculated. The slip angle of the vehicle 100 is an angle formed by the direction in which the vehicle is currently facing and the tangential direction of the target track, with the position of the center of gravity of the vehicle 100 as the apex.

Further, the feedforward control unit 207 calculates a second steering angle component that corrects the influence on the steering angle due to the deviation between the azimuth angle measurement value and the slip angle. The effect of the deviation between the azimuth measurement value and the slip angle on the steering angle will be described in detail later, but the feedback control calculated by the feedback control unit 206 caused by the deviation between the azimuth measurement value and the slide angle The deviation of the quantity δ _FB from the correct feedback control quantity. _{In the following description, the deviation of the feedback control amount δ FB} calculated by the feedback control unit 206 from the correct feedback control amount is referred to as a feedback deviation. Then, the feedforward control unit 207 calculates the feedforward control amount based on the first steering angle component and the second steering angle component.

As shown in FIG. 3, the feedforward control unit 207 includes curvature information, curvature target value, curvature change information, cross slope information, vehicle speed information, lateral position information, and proportional gain used in the feedback control unit 206. (K _p ) is input. The feedforward control unit 207 applies the input parameters to the two-wheel model, which is a general vehicle motion model, to correct the influence of the road shape, the first steering angle component, and the feedback deviation. 2 Steering angle component and. Parameters such as road curvature, curvature change, cross slope, vehicle speed, etc. are parameters used to describe the motion of a vehicle in a two-wheeled model.

FIG. 4 is a diagram for explaining a two-wheeled model. In FIG. 4, TyreF _{y_f} is an external force applied to the front wheels (tire lateral force), TyreF _{y_r} is an external force applied to the rear wheels (tire lateral force), angle β is the sliding angle at the center of gravity of the vehicle, and l _f is the front wheel axle and the center of gravity position. _{, L r} is the distance between the rear wheel axle and the position of the center of gravity, δ is the steering angle of the front wheels, and V is the vehicle speed. In addition, Grav. _{Phy_f} is the lateral force applied to the front wheels due to the cross slope of the road, Grav. _{Phy_r} is the lateral force applied to the rear wheels due to the cross slope of the road.

From such a two-wheel model, the following equations (1) and (2) can be formulated.

In the formula (1) and (2), m is the vehicle weight, gamma yaw angular velocity, [delta] _FF is a feed forward control amount, K _f is the cornering power of the front wheel shaft, K _r is the cornering power of the rear wheel shaft, L is the forward gaze The distance. Further, l _c is the distance between the camera and the position of the center of gravity, ρ is the curvature, I is the moment of inertia, l is the wheelbase, and n is the steering gear ratio. _{The term (−K p} L / n (β + l _c ρ)) in the equations (1) and (2) is a term for correcting the feedback deviation.

Lateral force Grav. On the front and rear wheels due to the cross slope. _{Phy_f} and Grav. _{Phy_r} is represented by the following equations (3) and (4). Note that θ _f indicates the cross slope at the position of the front wheel 103, and θ _r indicates the cross slope at the position of the rear wheel 104.

When the slip angle β is eliminated from the equations (1) to the equation (4) and the following equations (5) and (6) are introduced, the feedforward control amount δ _FF can be expressed by the equation (7).

FIG. 5 is a diagram for explaining the properties of each term of the formula (7). As shown in FIG. 5, the first to third terms of the equation (7) are the three parameters due to the road shape, that is, the first steering for correcting the influence of the curvature, the cross slope, and the change in curvature. It is a horn component. The fourth term of the equation (7) is a second steering angle component for correcting the feedback deviation.

Further, the feedforward control unit 207 feeds back the compensation value calculated based on the parameter error or the like to each term of the _{feedforward control amount δ FF} calculated by the equation (7) using the two-wheel model. Perform compensation processing. The error compensation process, in FIG. 3, the horizontal position information integrator (1 / s) is input calculated the compensation values K _i is the feed forward control amount [delta] _FF is calculated using the two-wheel model On the other hand, it corresponds to the part to be integrated.

In the vehicle 100 traveling by automatic steering control, the causes of the lateral position deviation (deviation) from the target track are as follows, for example. If any of the wheels (front wheels 103 and rear wheels 104) of the vehicle 100 have deteriorated over time, or if the friction coefficient of the road is low, the cornering power used in the above equations (1) and (2). May have an error. Further, if there is an air bleeding from the suspension of the vehicle 100, a measurement error of the vehicle height sensor, or the like, an error may occur in the position of the center of gravity used in the above equations (1) and (2).

Further, in the front image of the vehicle 100 taken by the camera 105, for example, when the white line drawn on the road cannot be accurately recognized, the center position of the road cannot be accurately known, so that the horizontal is derived based on the front image. There may be an error in the position information. In addition, the cross slope information, which is a parameter generated based on the image, may have an error if the road cannot be accurately recognized from the front image.

As described above, when there is an error in the parameters used for the automatic steering control, the steering amount calculated by the steering angle calculation unit 205 is a value including the error. Deviation from the orbit can occur.

Further, when the steering of the vehicle 100 has more play than necessary, the actual steering angle of the vehicle 100 may differ from the steering angle calculated by the steering amount calculation unit 205. Even in such a case, the lateral position of the vehicle 100 may be displaced.

Error compensation processing by the feedforward controller 207, by the compensation value K _i which is calculated based on such displacement of the lateral position, is a process of compensating for the effect [delta] _FF to the feed forward control amount due to the deviation of the lateral position. Hereinafter, the error compensation processing will be described in detail.

In the equation (8), assuming that the transverse gradient θ is uniform in the front and rear of the vehicle 100 in the above equation (7), the transverse gradient θ _{f of the} front wheels and the transverse gradient θ _{r of the} rear wheels are set to the entire vehicle 100. After simplifying to one value in, the equation is modified so as to be divided into three parameters of curvature ρ, cross slope θ, and curvature change dρ / dx.

In the equation (8), the first term is a term relating to the curvature ρ, the second term is a term relating to the cross slope θ, and the third term is a term relating to the curvature change dρ / dx. In the formula (8), the fourth term (second steering angle component for correcting the feedback deviation) in the formula (7) is assigned to any of the first to third terms.

Is calculated by the error compensation process, compensated feedforward control amount [delta] _{FF_C} the first term of equation (8), the second term, and the third term, the compensation value _{K i1, K i2,} and _{K i3} It is the value obtained by adding the totals of each. Equation (9) is an equation for calculating the _{compensated feedforward control amount δ FF_C.} In this specification, the compensation value _{K i1, K i2,} and are collectively _{K i3,} sometimes simply referred to as a compensation value _{K i.}

In the equation (9), the compensation value _{Ki 1} is a value for correcting the influence of the error on the curvature ρ, and the compensation value _{Ki 2} is a value for correcting the influence of the error on the cross slope θ, and is compensated. the value K _i3 is a value for correcting the influence of an error related to the curvature change dp / dx. In this way, the error compensation processing is calculated for each of the three parameters of the curvature ρ, the transverse gradient θ, and the curvature change dρ / dx, which greatly contribute to the calculation of _{the feedforward control amount δ FF.} It is done by accumulating the compensation values.

The initial values of the compensation values K _i1 , _{Ki 2} , and _{Ki 3} are set to 1.0, and the lateral position deviation is integrated by the integrator to obtain a predetermined range (for example, 0.5 to 1.5). Range). The compensation values K _i1 , _{Ki 2} , and _{Ki 3} are calculated as follows, for example.

6A, 6B, and 6C are flowcharts showing the calculation processing of _{the compensation values Ki1} , _Ki2 , and _Ki3. The processes shown in FIGS. 6A to 6C are repeated at predetermined minute time intervals.

As shown in FIG. 6A, in the calculation process of the compensation values K _i1 to correct the influence of the error for the curvature [rho, the curvature [rho at that time T1, the curvature change dp / dx, and lateral position of the displacement amount Lat. Only when the magnitude of error satisfies the condition, the integration of the lateral position deviation is performed, and when the condition is not satisfied, the integration is not performed. In addition, in FIGS. 6A to 6C, the threshold values th1 to th4 are predetermined threshold values set in advance. Further, in the processing shown in FIG. 6C from FIG. 6A, as the compensation values K _i of when the integration is not performed, which is calculated before a minute time, the previous compensation values K _i are used as it is.

As shown in FIG. 6A, in the calculation process of the compensation values K _i1 to correct the influence of the error for the curvature [rho, and the curvature [rho threshold th1 or more and curvature change dp / dx is the threshold th2 or less, and the lateral position Amount of deviation Lat. Integral is performed only when the error is equal to or higher than the threshold value th3. That is, when the ratio of the curvature ρ _{contributing to the calculation of the feedforward control amount δ FF} is relatively large compared to other parameters, in other words, only when the influence of the curvature ρ is large as the cause of the lateral position deviation. , It means that the compensation value _Ki1 is set to the value obtained by integrating the amount of deviation of the lateral position. Conversely, if the ratio of the curvature ρ _{contributing to the calculation of the feedforward control amount δ FF} is relatively small compared to other parameters, in other words, the influence of the curvature ρ is the cause of the lateral displacement. If it is small, it means that the compensation value _Ki1 is not set to the value obtained by integrating the amount of deviation of the lateral position, but is set to a value close to the initial value of 1.0. By such a process, the influence of the error of the curvature ρ on the feedforward control amount δ _FF can be preferably compensated.

Further, as shown in FIG. 6B, in the process of calculating the compensation values K _i2 to correct the influence of errors regarding cross slope theta, cross slope theta at that time T1, the curvature change dp / dx, and lateral position of the displacement amount Lat. Only when the magnitude of error satisfies the condition, the integration of the lateral position deviation is performed, and when the condition is not satisfied, the integration is not performed.

As shown in FIG. 6B, in calculation of the compensation value K _i2 to correct the influence of errors regarding cross slope θ is the cross slope θ is a threshold value th4 or more, the curvature change dp / dx is the threshold th2 or less, Horizontal position deviation amount Lat. Integral is performed only when the error is equal to or higher than the threshold value th3. That is, when the ratio of the cross slope θ _{contributing to the calculation of the feedforward control amount δ FF} is relatively large as compared with other parameters, in other words, the influence of the cross slope θ is large as a cause of the lateral position deviation. Only in the case, _{it means that the compensation value Ki2} is set to the value obtained by integrating the amount of deviation of the lateral position. Conversely, if the _{ratio of the cross slope θ contributing to the calculation of the feedforward control amount δ FF} is relatively small compared to other parameters, in other words, the cause of the lateral position shift is the cross slope θ. When the influence is small, it means that the compensation value _Ki2 is not set to the value obtained by integrating the amount of deviation of the lateral position, but is set to a value close to the initial value of 1.0. By such a process, the influence of the error of the cross gradient θ on the feedforward control amount δ _FF can be preferably compensated.

Furthermore, as shown in FIG. 6C, the process of calculating the compensation values K _i3 to correct the influence of errors related to curvature change dp / dx, the curvature ρ at the time T1, the curvature change dp / dx, and the lateral positional deviation amount Lat .. Only when the magnitude of error satisfies the condition, the integration of the lateral position deviation is performed, and when the condition is not satisfied, the integration is not performed.

As shown in FIG. 6C, with calculation of the compensation value K _i3 to correct the influence of the error is related to the curvature change dp / dx, and the curvature ρ is the threshold value th1 or more and is greater than the threshold value th2 curvature change dp / dx, and, Horizontal position deviation amount Lat. Integral is performed only when the error is equal to or higher than the threshold value th3. That is, when the ratio of the curvature change dρ / dx _{contributing to the calculation of the feedforward control amount δ FF} is relatively large as compared with other parameters, in other words, the curvature change dρ / dx is the cause of the lateral position deviation. _{It means that the compensation value Ki3} is set to the value obtained by integrating the amount of deviation of the lateral position only when the influence of is large. Conversely, if the ratio of the curvature change dρ / dx _{contributing to the calculation of the feedforward control amount δ FF} is relatively small compared to other parameters, in other words, the curvature change is the cause of the lateral position shift. If the influence of dp / dx is small, the compensation value K _i3 is not is set to a value obtained by integrating the deviation amount in the lateral position, which means that it is set to a value close to the initial value 1.0. By such processing, the influence of the error of the curvature change dρ / dx on the feedforward control amount δ _FF can be preferably compensated.

Thus, the feed-forward controller 207, the curvature [rho, calculated cross slope theta, every three parameters curvature change dp / dx, the compensation value _{K i1, K i2, K i3} based on the size of each parameter Then, the compensated feedforward control amount δ _{FF_C} is calculated using the compensation value. By such an error compensation process, it is possible to suitably suppress the deviation of the lateral position of the vehicle 100 from the target track due to a parameter error or the like.

In the error compensation process described above, it was determined whether or not to integrate each of the three parameters of curvature ρ, cross slope θ, and curvature change dρ / dx based on the condition of the magnitude of each parameter. However, for example, the following judgment may be added. For example, when the reliability of the front image of the vehicle 100 used for calculating parameters such as curvature ρ, cross slope θ, and curvature change dρ / dx is smaller than a predetermined threshold value, all compensation values K _i1 and K _The integration may not be performed in the calculation processing of i2 and _Ki3. The reliability of the front image is a value calculated based on the image quality of the front image captured by the camera 105, the degree of clarity of the object (road shape, white line, etc.) captured in the image, and the camera 105 or. It can be calculated by a reliability calculation unit (not shown). By adding such a judgment, when the reliability of the image is low and it is expected that the error compensation is not preferably performed, the influence of the error compensation processing on the steering amount can be reduced.

<Action, effect>
The automatic steering control device 200 according to the embodiment of the present disclosure is an automatic steering control device 200 that automatically controls the steering angle of the vehicle 100 so that the vehicle 100 follows a target trajectory, and is an automatic steering control device 200 of the azimuth angle of the vehicle 100. _{Feedback control amount δ FB,} which is a steering angle that corrects the deviation between the measured azimuth angle value and the azimuth angle target value based on the measured azimuth angle measured value and the azimuth angle target value for traveling on the target trajectory. _{The feedforward control amount δ FF} for correcting the deviation of the _{feedback control amount δ FB} is calculated by using the feedback control unit 206 for calculating the feedback control unit 206 and the motion model when the vehicle 100 travels so as to pass through the target trajectory. Then, using the calculated feedforward control amount δ _FF , the feedforward control unit 207 calculates _{the compensated feedforward control amount δ FF_C} that compensates for the influence of the lateral deviation amount of the vehicle 100 from the target track. It includes a steering control unit 208 that performs steering control based on a feedback control amount and a feedforward control amount.

With such a configuration, automatic steering control based on _{the compensated feedforward control amount δ FF_C} that compensates for the influence of the lateral deviation amount of the vehicle 100 from the target trajectory, which is caused by, for example, a parameter error, is performed. Can be done. Therefore, it becomes possible to improve the follow-up performance to the target trajectory in the automatic steering control.

Further, according to the automatic steering control device 200 according to the embodiment of the present disclosure, the feedforward control unit 207 has at least the curvature and curvature of the road among a plurality of parameters for describing the motion of the vehicle 100 in the two-wheel model. The amount of change in the amount of change or the feedforward control amount having the components calculated for each of the three parameters of the cross slope of the road is calculated, and the lateral deviation of the vehicle 100 from the target track calculated for each of these three parameters. _{The compensated feedforward control amount δ FF_C} is calculated by integrating the compensation value K for compensating for the influence of the quantity into the components calculated for each of the three parameters. The compensation value is calculated by integrating the amount of lateral displacement of the vehicle for each parameter.

With such a configuration, it is possible to suitably compensate for parameters such as the curvature of the road, the amount of change in curvature, or the cross slope of the road, which have a large effect on the feedforward control amount when an error occurs. become.

(Modification example)
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

In the embodiment described above, it is not assumed that the driver controls the vehicle 100, but the automatic steering running by the automatic steering control device of the present disclosure and the running driven by the driver are arbitrarily switched. You may be able to do it.

The present disclosure can be applied to an automatic steering control device that performs steering control that automatically follows a lane or a road.

100 Vehicle 101 Cab 102 Loading platform 103 Front wheel 104 Rear wheel 105 Camera 200 Automatic steering control device 201 Lateral position information generation unit 202 Azimuth measurement value information generation unit 203 Road shape information generation unit 204 Vehicle speed sensor 205 Steering amount calculation unit 206 Feedback control unit 207 Feedforward control unit 208 Steering control unit

Claims (10)

An automatic steering control device that automatically controls the steering angle of the vehicle so that the vehicle follows the target trajectory.
The deviation between the azimuth measurement value and the azimuth target value is corrected based on the azimuth measurement value which is the measurement value of the azimuth angle of the vehicle and the azimuth target value for traveling on the target track. A feedback control unit that calculates the feedback control amount, which is the steering angle,
The feedforward control amount for correcting the deviation of the feedback control amount is calculated by using the motion model when the center of gravity of the vehicle travels along the target trajectory, and the calculated feedforward control amount is used. , A feedforward control unit that calculates a compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target track.
A steering control unit that performs steering control based on the feedback control amount and the compensated feedforward control amount, and
An automatic steering control device. The feedforward control unit
Among the plurality of parameters for describing the motion of the vehicle in the motion model, the feedforward control amount having a component calculated for at least one of the parameters is calculated.
The compensated feed is calculated by integrating the compensation value calculated for each parameter for compensating for the influence of the lateral deviation amount of the vehicle from the target track into the component calculated for each parameter. Calculate the forward control amount,
The automatic steering control device according to claim 1. The plurality of parameters include at least one of the curvature of the road, the amount of change in the curvature, or the cross slope of the road.
The automatic steering control device according to claim 2. The compensation value is a value obtained by integrating the lateral displacement amount of the vehicle for each of the parameters.
The automatic steering control device according to claim 2 or 3. The effect on the steering angle is caused by the deviation between the measured azimuth angle and the slip angle of the vehicle when the center of gravity of the vehicle travels along the target trajectory, and the feedback control amount is correct. Deviation from feedback control amount,
The automatic steering control device according to any one of claims 1 to 4. The feedforward control unit calculates the feedforward control amount based on the distance between the apex position of the azimuth angle and the position of the center of gravity.
The automatic steering control device according to any one of claims 1 to 5. The feedback control unit corrects the deviation between the azimuth measurement value and the azimuth target value by using proportional control.
The feedforward control unit calculates the feedforward control amount based on the distance between the apex position of the azimuth angle measurement value and the position of the center of gravity, and the proportional gain of the proportional control.
The automatic steering control device according to any one of claims 1 to 6. The feedback control unit calculates the feedback control amount using the forward gaze model, and obtains the feedback control amount.
The feedforward control unit uses the feedforward control amount based on the distance between the apex position of the azimuth measurement value and the position of the center of gravity, the proportional gain of the proportional control, and the forward gaze distance in the forward gaze model. To calculate,
The automatic steering control device according to claim 7. It is an automatic steering control method that automatically controls the steering angle of the vehicle so that the vehicle follows the target trajectory.
The deviation between the azimuth measurement value and the azimuth target value is corrected based on the azimuth measurement value which is the measurement value of the azimuth angle of the vehicle and the azimuth target value for traveling on the target track. Calculate the feedback control amount, which is the steering angle,
The feedforward control amount for correcting the deviation of the feedback control amount is calculated by using the motion model when the center of gravity of the vehicle travels along the target trajectory.
Using the calculated feedforward control amount, a compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target track is calculated.
Steering control is performed based on the feedback control amount and the compensated feedforward control amount.
Automatic steering control method. An automatic steering control program that automatically controls the steering angle of the vehicle so that the vehicle follows the target trajectory.
The deviation between the azimuth measurement value and the azimuth target value is corrected based on the azimuth measurement value which is the measurement value of the azimuth angle of the vehicle and the azimuth target value for traveling on the target track. The procedure for calculating the feedback control amount, which is the steering angle, and
A procedure for calculating a feedforward control amount for correcting a deviation of the feedback control amount using a motion model when the center of gravity of the vehicle travels along the target trajectory, and a procedure for calculating the feedforward control amount.
Using the calculated feedforward control amount, a procedure for calculating a compensated feedforward control amount that compensates for the influence of the lateral deviation amount of the vehicle from the target trajectory, and a procedure for calculating the compensated feedforward control amount.
A procedure for performing steering control based on the feedback control amount and the compensated feedforward control amount, and
An automatic steering control program that causes the processor of the vehicle to execute.

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