Driving assistance device

Abstract

When a saddle-type vehicle travels along a curved road, steering assistance control is performed to prevent a driver of the saddle-type vehicle from feeling a difference from the driver's expectations. A driving assistance device comprises: an environmental situation detection section (21) configured to detect an environmental situation of the saddle-type vehicle; a driving state detection section (22) configured to detect a driving state of the saddle-type vehicle;and a control section (23) configured to, when it is recognized from the surrounding situation that the saddle-type vehicle is traveling along a curved road, determine whether a predicted traveling path of the saddle-type vehicle deviates from a lane of interest of the saddle-type vehicle, the predicted traveling path being based on the driving state, the lane of interest being recognized from the surrounding situation, and, when the predicted traveling path deviates from the lane of interest, set a target passing point according to a curvature of the curved road, the target passing point being within the lane of interest in a traveling direction of the saddle-type vehicle, and perform steering assist control that actuates a steering device (42) included in the saddle-type vehicle based on the target passing point;

Description

[Technical field]

[0001] The present invention relates to a driving support device. [Technical background]

[0002] Conventional driving assistance devices for semi-trailer-type vehicles perform a control operation that actuates the steering mechanism of the semi-trailer-type vehicle, causing the vehicle to move within a lane recognized from an image captured by a camera (see, for example, patent literature 1). In patent literature 1, when the semi-trailer-type vehicle moves along a curve (a winding road), the steering mechanism is controlled to operate at times before the vehicle enters the curve, while the vehicle is moving through the curve, and after the vehicle exits the curve, so that the semi-trailer-type vehicle moves within a lane along a path of movement that runs from an outer part to a middle part and then to the outer part of the lane. [List of citations][Patent literature]

[0003] [Patent Literature 1] International Publication WO 2020 / 202266 [Outline of the invention][Technical problem]

[0004] The conventional driving assistance device described above switches a steering control more than once when the saddle-type vehicle moves along a winding road, causing the driver of the saddle-type vehicle to perceive a difference from the driver's expectations.

[0005] The present invention has been made in light of the background described above and has an objective of providing a driving assistance device which can perform steering assistance control and prevent a driver of a semi-trailer-type vehicle from perceiving a difference from the driver's expectations when the semi-trailer-type vehicle is moving along a curved road. [Solution to the task]

[0006] The Japanese patent application No. 2022-201227, filed on December 16, 2022, is included herein in its entirety.

[0007] In one aspect of solving the problem described above, a driving assistance device is provided which assists in steering a semi-trailer-type vehicle (1), wherein the driving assistance device comprises: an environment situation detection section (21) which is configured to detect an environment situation of the semi-trailer-type vehicle; a driving state detection section (22) which is configured to detect a driving state of the semi-trailer-type vehicle;and a control section (23) which is configured, when it is detected from the environment that the semi-trailer-type vehicle is moving along a curved road, to determine whether a predicted movement path of the semi-trailer-type vehicle deviates from a track of interest of the semi-trailer-type vehicle, wherein the predicted movement path is based on the driving condition, wherein the track of interest is detected from the environment, and if the predicted movement path deviates from the track of interest, to set a target crossing point which corresponds to a curvature of the curved road, wherein the target crossing point lies within the track of interest in a direction of movement of the semi-trailer-type vehicle, and to perform a steering assistance control which actuates a steering device (42) which is included in the semi-trailer-type vehicle, based on the target crossing point. [Advantageous effects of the invention]

[0008] The driving assistance device described above can perform steering assistance control and prevent a driver of a saddle-type vehicle from experiencing a difference from the driver's expectations when the saddle-type vehicle travels along a winding road. [Brief description of the drawings] [ Fig. 1] Fig. Figure 1 is a configuration diagram of a driving assistance device and a saddle-type vehicle, which includes the driving assistance device. [ Fig. 2] Fig. Figure 2 is a flowchart for a steering assistance control system implemented by a driving assistance device. [ Fig. 3] Fig. Figure 3 is a diagram describing a recognized aspect of a saddle-type vehicle's movement path with respect to a track of interest. [ Fig. 4] Fig. Figure 4 is a diagram describing a calculation process for a turning radius of the articulated vehicle. [ Fig. 5] Fig. Figure 5 is a diagram to describe a setting aspect of a target crossing point. [ Fig. 6] Fig. Figure 6 is a diagram describing a calculation process for a roll angle of the saddle-type vehicle. [Description of embodiments][1. Configuration of a driving support device]

[0009] With reference to Fig. Figure 1 describes a configuration of a driving assistance device according to the present disclosure. The driving assistance device according to the present disclosure is configured as part of the function of a vehicle control device 10, which is included in a vehicle 1 and controls the overall operation of the vehicle 1. The vehicle 1 is a saddle-type vehicle, which is driven by a rider sitting astride a vehicle body. In addition to motorcycles, the vehicle 1 includes three-wheeled vehicles (which have one front wheel and two rear wheels or two front wheels and one rear wheel), which are categorized as ATVs (All-Terrain Vehicles), and four-wheeled vehicles.

[0010] The vehicle 1 comprises: a driving assistance switch 51, which switches a driving assistance function ON / OFF, such as a steering assistance control, which is described below; a throttle sensor 52, which detects a degree of manipulation performed on a throttle by an acceleration manipulation section (such as a throttle grip); a brake sensor 53, which detects a degree of manipulation performed on a brake by a brake manipulation section (such as a brake lever and brake pedal); a speed sensor 54, which detects a propulsion speed of the vehicle 1; an IMU (Inertial Measurement Unit) sensor 55; and an environment view camera 56, which captures an image of the environment of the vehicle 1.The IMU sensor 55 detects an angular velocity and an acceleration of the vehicle 1 by using a gyroscope with three orthogonal axes and an accelerometer.

[0011] The vehicle control device 10 receives: a manipulation signal from the drive assist switch 51; detection signals from the gas sensor 52, the brake sensor 53, the speed sensor 54 and the IMU sensor 55; and a captured image from the surround view camera 56.

[0012] The vehicle 1 further comprises a drive device 40, a brake device 41 and a steering device 42. The operation of the drive device 40, the brake device 41 and the steering device 42 are controlled by respective control signals TR_c, BK_c and ST_c, which are output by the vehicle control device 10.

[0013] The vehicle control device 10 is a control unit comprising a processor 20 and a memory 30. The memory 30 contains a program 31 for controlling the vehicle control device 10. The processor 20 acts as an environment situation detection section 21, a driving state detection section 22, and a control section 23 by reading and executing the program 31.

[0014] The environmental situation detection section 21 detects a lane in which the vehicle 1 is moving (lane of interest) as an environmental situation of the vehicle 1, based on an image captured by the surround view camera 56. The environmental situation detection section 21 detects the position of the lane of interest (the positions of a left boundary line and a right boundary line) relative to the vehicle 1. The driving state detection section 22 detects a driving state of the vehicle 1 based on detection signals from the speed sensor 54 and the IMU sensor 55.When in a driving assistance mode, which is started by switching ON the driving assistance switch 51, the control section 23 performs the steering assistance control, which actuates the steering device 42 to allow the vehicle 1 to prevent leaving the lane of interest, which is detected by the environmental situation detection section 21. [2. Steering Assist Control]

[0015] One in Fig. Following the flowchart shown in section 2 and with reference to Fig. Sections 3 to 6 below describe the steering support control, which is carried out by the vehicle control device 10 when the vehicle 1 is moving along a curved road (a curve).

[0016] In Fig. In step S1, the environmental situation recognition section 21 detects a boundary line of a track of interest in which the vehicle 1 is moving, from an image taken by the environmental view camera 56. Fig. Figure 3 shows a detected situation of a left boundary line SL and a right boundary line SR of the lane of interest, as detected by the environment situation detection section 21, where Y represents a lane width direction of the lane of interest and X represents a direction of travel of vehicle 1.

[0017] In the subsequent step S2, the vehicle state detection section 22 detects the speed of vehicle 1 based on a detection signal from the speed sensor 54 and detects the yaw rate, pitch rate, and roll angle of vehicle 1 based on a detection signal from the IMU sensor 55. In the subsequent step S3, the control section 23 calculates a turning radius of vehicle 1 using expression (1) and expression (2), which are shown below. [Expression 1] ω=(ωy×sin φ+ωz×cos φ)×2π360 where ω represents a yaw rate (degrees / s) of vehicle 1 with respect to a horizontal plane; ωy represents a pitch rate (degrees / s) of vehicle 1; ωz represents a yaw rate (degrees / s) of vehicle 1 and φ represents a roll angle (degrees) of vehicle 1. [Expression 2] R=Vω where R represents the turning radius of vehicle 1; V represents the speed of vehicle 1 and ω represents the yaw rate of vehicle 1 with respect to the horizontal plane.

[0018] In the subsequent step S4, the control section 23 calculates a predicted movement path DT of vehicle 1 according to the turning radius R, which is in Fig. Figure 3 is shown. In the subsequent step S5, control section 23 determines whether the predicted locomotion path DT deviates from the track of interest. Specifically, control section 23 determines whether the predicted locomotion path DT deviates from the track of interest by checking whether the passage points P1, P2, and up to P5 of the predicted locomotion path DT, at their respective passage lines L1-R1, L2-R2, and up to L5-R5, are located on a left side of the left boundary line SL or on a right side of the right boundary line SR (outside the track of interest) in a locomotion direction along the track of interest.

[0019] Fig. Figure 4 shows a method for calculating a distance Y_tg in the track width direction from vehicle 1 to a crossing point P, where the crossing point P is located X away from vehicle 1 in the direction of travel of vehicle 1. Fig. 4 represents CC, the center of rotation of vehicle 1, and R represents the radius of rotation. From the in Fig. The relationship shown in 4 can be calculated using expression (3) shown below. [Expression 3] Y_tg=R−R2−X2 where Y_tg represents the distance in the track width direction from vehicle 1 to the crossing point P; R represents the turning radius of vehicle 1 and X represents a distance in the direction of movement of vehicle 1 from vehicle 1 to the crossing point P.

[0020] Assume that a lateral left turn of vehicle 1 is positive and a lateral right turn of vehicle 1 is negative. When vehicle 1 turns left, the position of the point of transition P in the track's width direction is the position of vehicle 1 plus Y_tg. When vehicle 1 turns right, the position of the point of transition P in the vehicle's width direction is the position of vehicle 1 minus Y_tg.

[0021] Control section 23 determines that the point of passage P deviates from the track of interest if the position of the point of passage P in the vehicle's transverse direction falls on the right side of a corresponding point on the right boundary line SR, or if the position of the point of passage P in the vehicle's transverse direction falls on the left side of the left boundary line SL. For example, determined in an example in Fig. 3, if the position of the point of passage P5 in a Y direction is on the right side of R5 (if the Y coordinate value for P5 is less than the Y coordinate value for R5), or if the position of the point of passage P5 in the Y direction is on the left side of L5 (if the Y coordinate value for P5 is greater than the Y coordinate value for L5), the control section 23 indicates that the point of passage P5 deviates from the track of interest.

[0022] If control section 23 determines that any point of transit deviates from the track of interest, control section 23 determines that the predicted path of motion DT of vehicle 1 deviates from the track of interest, and processing proceeds from step S5 to step S6. If control section 23 determines that all points of transit lie within the track of interest, control section 23 determines that the predicted path of motion of vehicle 1 does not deviate from the track of interest, and processing proceeds from step S5 to step S1.

[0023] In step S6, the control section 23 calculates a target turning radius and a target yaw rate, which bring the predicted movement path of vehicle 1 into the track of interest. Fig. Figure 5 shows an example situation in which the predicted path DT of vehicle 1 deviates from the track of interest at a point DP located outside the path. In this case, the control section 23 sets a target crossing point TP on the line L5-R5 that is furthest from vehicle 1. Normally, the control section 23 sets a midpoint between LR and R5 on the line LR-R5 as the target crossing point TP; however, in accordance with a situation such as a curve in the track of interest, which is detected by the environment situation detection section 21, the control section 23 sets the position of the target crossing point using one of a first through a fourth pattern, which are described below.

[0024] The first pattern: the track of interest curves to the right and the radius of rotation R is small (a large curvature), (a tight curve, which, for example, has a radius equal to or less than 300 m).

[0025] In this case, the target crossing point TP is shifted in the direction of the right boundary line SR. For example, the position of the target crossing point TP in the Y-direction Y-TP is calculated using expression (4) described below. [Expression 4] Y_TP=(Y_L5−Y_R5)×0.25+Y_R5 where Y_TP represents the position of the target crossing point TP in the Y direction (Y-coordinate position); Y_L5 represents the position of L5 in the Y direction (Y-coordinate position); T_R5 represents the position of R5 in the Y direction (Y-coordinate position); and 0.25 is an adjustment factor. If the adjustment factor is set to 0.5, Y_TP is located midway between Y_L5 and Y_R5, and if the adjustment factor is set greater than 0.5, Y_TP is shifted towards Y_L5.

[0026] The second pattern: the trace of interest curves to the left and the rotary radio R is small (a large curvature).

[0027] In this case, the adjustment factor in expression (4) is set to 0.75, so that the target crossing point TP is shifted in the direction of the left boundary line SL.

[0028] The third pattern: the track of interest is straight and vehicle 1 is approaching the left boundary line SL.

[0029] In this case, the adjustment factor in expression (4) is set to 0.75, so that the target crossing point TP is shifted in the direction of the right boundary line SR.

[0030] The fourth pattern; the track of interest is straight and vehicle 1 is approaching the right boundary line SR.

[0031] In this case, the adjustment factor in expression (4) is set to 0.25, so that the target crossing point TP is shifted in the direction of the left boundary line SL.

[0032] Furthermore, the adaptation factor in expression (4) can be varied linearly in accordance with the state of curvature or straightness of the track of interest. By varying the adaptation factor, the degree of intervention of the steering control to prevent lane departure can be changed. For example, by placing the target crossing point TP at a position where the distance from the target crossing point TP to the boundary line closer to the center of rotation decreases as the curvature of the track of interest (the curvature of the curved road) increases, assistance can be provided to steer vehicle 1 to a large extent.By placing the target crossing point TP at a position where the distance from the target crossing point TP to the boundary line closer to the center of rotation increases as the curvature of the track of interest decreases, the steering of vehicle 1 can be assisted while preventing excessive steering input. Furthermore, by placing a point close to vehicle 1 at a distance in the Y-direction than the target crossing point, the intervention of the steering assist control can be reduced.

[0033] Control section 23 calculates a target turning radius R_tg from the target crossing point TP, which has been set. From the relationship between the target crossing point TP and the turning radius R of vehicle 1, which is in Fig. As shown in 4, the following expression (5) is obtained. [Expression 5] R_tg2=X2+(R_tg−Y_tg)2 where R_tg represents the target turning radius; X represents a distance in the direction of travel of vehicle 1 between vehicle 1 and the target crossing point TP; and Y_tg represents a distance in the track width direction of the track of interest between vehicle 1 and the target crossing point TP.

[0034] The target turning radius R_tg can be calculated using expression (6) shown below, which is a transformation of expression (5). [Expression 6] R_tg=X2+Y_tg22×Y_tg

[0035] The control section 23 calculates a target yaw rate ω_tg using an expression (7) shown below. [Expression 7] ω_tg=VR_tg where ω_tg represents the target yaw rate; V represents the speed of vehicle 1; and R_tg represents the target turning radius.

[0036] In step S7, the control section 23 determines the control signal ST_c for the steering device 42 and the control signal TR_c for the drive device 40, so that the vehicle 1 moves along a predetermined movement path which corresponds to the target turning radius R_tg at the target yaw rate w_tg, and outputs the determined control signals ST_c and TR_c to the steering device 42 and the drive device 40 respectively.

[0037] In the subsequent step S8, the control section 23 calculates the roll angle of vehicle 1, which occurs when vehicle 1 moves at the target turning radius R_tg, using an expression (8) shown below. Fig. Figure 6 shows a state in which vehicle 1 is rolling, where the roll angle φ, a centrifugal acceleration M, and a gravitational acceleration g of vehicle 1 with respect to a center of mass 70 of vehicle 1 are shown, where Z represents a vertical direction. The centrifugal acceleration M can be calculated using expression (8) shown below. [Expression 8] M=V2|R| where M represents the centrifugal acceleration; V represents the speed of vehicle 1 and R represents the turning radius of vehicle 1.

[0038] In a state where vehicle 1 has a stable tilt, expression (9), which is an approximate expression, is considered to express the equilibrium in a lateral vehicle body direction. Thus, the roll angle φ can be calculated using expression (10) shown below. [Expression 9] g×sin φ≈M×cos φ where φ represents the roll angle; g represents the center-of-mass acceleration and M represents the centrifugal acceleration. [Expression 10] φ=tan−1Mg

[0039] In the subsequent step S9, the control section 23 determines whether the roll angle φ is greater than a predetermined angle (for example, 20 degrees), and thus whether excessive speed leads to excessive bank angle.

[0040] If excessive lean angle occurs, control section 23 proceeds to step S10. If no excessive lean angle occurs, control section 23 proceeds to step S1.

[0041] In step S10, the control section 23 determines the control signal BK_c for the brake device 41 such that the roll angle φ is equal to or less than the predetermined angle, and outputs the determined control signal BK_c to the brake device 41 to perform deceleration control for the vehicle 1. The control section 23 repeats the steering assist control according to the Fig. 2 shown in the flowchart, and when the yaw rate of vehicle 1 with respect to the horizontal plane converges to the target yaw rate w_tg, the control section 23 terminates the steering support control.

[0042] By adjusting the steering assist control according to the in Fig. By following the flowchart shown in section 2, vehicle 1 can be made to move continuously within the target lane of interest along the turning radius. Therefore, it can be prevented that the driver of vehicle 1 experiences a difference from their expectations due to frequent steering control changes. [3. Other embodiments]

[0043] While control section 23 handles the delay control at steps S8 to S10 in Fig. 2, in order to prevent excessive tilting of the vehicle 1 in the embodiment described above, the processing of steps S8 to S10 can be omitted.

[0044] It should be noted that Fig. Figure 1 is a schematic diagram showing a functional configuration of the driving support device in such a way that the configuration is divided according to a main processing step to simplify understanding of the invention as disclosed herein. The functional configuration of the driving support device may be divided in other ways. The processing of each constituent element may be carried out by one hardware unit or a plurality of hardware units. Processes of each constituent element of the Fig. The driving assistance devices shown in point 2 can be implemented by one program or a plurality of programs. [5. Configurations supported by the embodiments described above]

[0045] The preceding embodiments describe specific examples of the following configurations.

[0046] (First configuration) A driving assistance device which assists in the steering of a semi-trailer-type vehicle (1), wherein the driving assistance device comprises: an environment situation detection section (21) which is configured to detect an environment situation of the semi-trailer-type vehicle; a driving condition detection section (22) which is configured to detect a driving condition of the semi-trailer-type vehicle;and a control section (23) which is configured, when it is detected from the environmental situation that the semi-trailer-type vehicle is moving along a curved road, to determine whether a predicted movement path of the semi-trailer-type vehicle deviates from a track of interest of the semi-trailer-type vehicle, wherein the predicted movement path is based on the driving condition, wherein the track of interest is detected from the environmental situation, and if the predicted movement path deviates from the track of interest, to set a target crossing point according to a curvature of the curved road, wherein the target crossing point lies within the track of interest in a direction of movement of the semi-trailer-type vehicle, and to perform a steering assistance control which actuates a steering device (42) which is included in the semi-trailer-type vehicle on the basis of the target crossing point.

[0047] According to the driving assistance device of the first configuration, steering assistance control can be carried out and it can be prevented that a driver of the saddle-type vehicle feels a difference from the driver's expectation when the saddle-type vehicle moves along a winding road.

[0048] (Second configuration) The driving assistance device according to the first configuration, wherein the control section sets the target crossing point at a position where a distance from a center of rotation of the saddle-type vehicle to the target crossing point in a track width direction of the track of interest decreases as the curvature of the curved road increases.

[0049] According to the driving assistance device of the second configuration, the semi-trailer-type vehicle can be steered to a large extent by shifting the target passage point towards the center of rotation of the semi-trailer-type vehicle in the lane width direction when a curved road has a large curvature (a tight curve).

[0050] (Third configuration) The driving assistance device according to the first configuration or the second configuration, wherein the control section sets the target crossing point at a position where a distance from a center of rotation of the saddle-type vehicle to the target crossing point in a track-width direction of the track of interest increases as the curvature of the curved road decreases.

[0051] According to the driving assistance device of the third configuration, adequate assistance can be provided in steering the saddle-type vehicle, preventing excessive steering by shifting the target passage point away from the center of rotation of the saddle-type vehicle in the track width direction when a curved road has a small curvature (a gentle curve).

[0052] (Fourth configuration) The driving assistance device according to one of the first configurations up to the fourth configuration, wherein, when the control section performs the steering assistance control and a yaw rate of the saddle-type vehicle with respect to a horizontal plane converges to a target yaw rate, the control section terminates the steering assistance control, the yaw rate being detected from the driving state.

[0053] According to the driving assistance device of the fourth configuration, the steering assistance control can be prevented from being performed repeatedly, and thus it can be expected that a driver of the saddle-type vehicle will receive a natural steering feel.

[0054] (Fifth configuration) The driving assistance device according to one of the first configurations up to the fourth configuration, wherein, when the control section performs the steering assistance control and a roll angle of the saddle-type vehicle is equal to or greater than a predetermined angle, the control section actuates a braking device which is included in the saddle-type vehicle, wherein the roll angle is detected from the driving state.

[0055] According to the fifth configuration of the driving support device, it is possible to prevent the roll angle of the saddle-type vehicle from becoming equal to or greater than the predetermined angle, and thus prevent the saddle-type vehicle from assuming an excessive tilt by applying the braking device to slow the saddle-type vehicle. [Commercial Applicability]

[0056] The driving assistance device according to the present disclosure can be used for the purpose of carrying out steering assistance control and to prevent a driver of a semi-trailer-type vehicle from feeling a difference from the driver's expectations when the semi-trailer-type vehicle is moving along a winding road. [List of reference symbols]

[0057] 1 Saddle-type vehicle, 10 Vehicle control device (driving assistance device), 20 Processor, 21 Environmental situation detection section, 22 Driving condition detection section, 23 Control section, 30 Memory, 31 Program, 40 Drive device, 41 Brake device, 42 Steering device, 51 Driving assistance switch, 52 Throttle sensor, 53 Brake sensor, 54 Speed ​​sensor, 55 IMU sensor, 56 Surround view camera QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 202266

[0003] JP 2022-201227

[0006]

Claims

[1] Driving assistance device which assists in steering a saddle-type vehicle (1), the driving assistance device comprising: an environmental situation detection section (21) which is designed to detect an environmental situation of the articulated vehicle; a driving condition detection section (22) which is designed to to recognize the driving condition of the articulated vehicle; and a control section (23) which is configured, when it is detected from the environmental situation that the semi-trailer-type vehicle is moving along a curved road, to determine whether a predicted movement path of the semi-trailer-type vehicle deviates from a track of interest of the semi-trailer-type vehicle, wherein the predicted movement path is based on the driving condition, wherein the track of interest is detected from the environmental situation, and if the predicted movement path deviates from the track of interest, to set a target crossing point according to a curvature of the curved road, wherein the target crossing point lies within the track of interest in a direction of movement of the semi-trailer-type vehicle, and to perform a steering assistance control which actuates a steering device (42) which is included in the semi-trailer-type vehicle, based on the target crossing point. [2] Driving support device according to claim 1, wherein the control section sets the target crossing point at a position where a distance from a center of rotation of the saddle-type vehicle to the target crossing point in a track width direction of the track of interest decreases as the curvature of the curved road increases. [3] Driving support device according to claim 1, wherein the control section sets the target crossing point at a position where a distance from a center of rotation of the saddle-type vehicle to the target crossing point in a track width direction of the track of interest increases as the curvature of the curved road decreases. [4] Driving assistance device according to one of claims 1 to 3, wherein, when the control section performs the steering assistance control and a yaw rate of the saddle-type vehicle with respect to a horizontal plane converges to a target yaw rate, the control section terminates the steering assistance control, wherein the yaw rate is detected from the driving state. [5] Driving assistance device according to one of claims 1 to 3, wherein, when the control section performs the steering assistance control and a roll angle of the saddle-type vehicle is equal to or greater than a predetermined angle, the control section actuates a braking device which is included in the saddle-type vehicle, wherein the roll angle is detected from the driving state.

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