Object detection system for a semi-trailer-type vehicle and semi-trailer-type vehicle

Abstract

Object detection system for a vehicle (1) of the articulated type, comprising: an object detection means (16, 17) for detecting a tracking target object; wherein the object detection means (16, 17) is provided on a handle (8) which is rotatable on a body of the vehicle (1); a tilt detection means (30) for detecting a tilt of a vehicle (1) of the articulated type; and a steering angle detection means for detecting a steering angle of the handle (8) of the body, characterized by a position specification means (120) for specifying a position of the tracking target object, which has been detected by the object detection means (16, 17), and correcting the position so that the inclination, which has been detected by the inclination detection means (30), is upright, and the steering angle of the handle (8), which is detected by the steering angle detection means, is directed straight ahead, a control device (110) for carrying out acceleration or deceleration control in order to maintain the distance to the tracking target object at a constant distance, and that the inclination detected by the inclination detection means (30) is an inclination caused by rolling of the vehicle (1) of the semi-trailer type and an inclination caused by pitching of the vehicle (1) of the semi-trailer type.

Description

[0001] The present invention relates to an object detection system for a semi-trailer-type vehicle which has a forward-facing detection function, and a semi-trailer-type vehicle which is equipped with the same. State of the art

[0002] An adaptive cruise control (ACC) function (hereinafter referred to as a following vehicle function or simply a following function), which is the function of detecting a vehicle traveling ahead using radar or the like and following the vehicle, has been developed and has begun to be installed in four-wheeled vehicles. The ACC requires a sensor, such as radar, to detect the vehicle ahead. Here, a semi-trailer-type vehicle, such as a two-wheeled vehicle, has a characteristic in that its body, for example when turning, is inclined towards the center of the turn (hereafter referred to as leaning or rolling), unlike a four-wheeled vehicle.Additionally, compared to a four-wheeled vehicle, a semi-trailer-type vehicle has a shorter wheelbase and is more prone to forward and backward tilting during braking or acceleration (referred to hereafter as pitching). Therefore, a sensor, such as a radar, will also be tilted when the vehicle body is tilted due to rolling or pitching, and the position of the detected object, particularly the vehicle ahead, may shift from the position detected when the vehicle is upright, potentially disrupting the tracking function. JP 2017-171 223 A proposes using a mounting module to rotate an image acquisition system in the direction opposite to the direction in which the vehicle body is tilted.

[0003] From DE 11 2015 001 698 T5 it is known to correct an image of a motorcycle taken by a camera with a detected roll angle. Summary of the invention: Technical problem

[0004] However, since JP 2017-171 223 A uses an attachment module, which is a complex mechanism, the system is expensive. Such a mechanism is also likely to be a source of error or similar issues due to its complexity. Furthermore, the image acquisition system rotates around only one axis, namely the roll axis.

[0005] The present invention was made with regard to the conventional example described above and aims to provide an object detection system for a semi-trailer-type vehicle and a semi-trailer-type vehicle which are capable of correcting an inclination using a simple configuration. Solution to the problem

[0006] To solve the problem, an object detection system for a semi-trailer-type vehicle according to claim 1 is provided according to the invention. (1) According to the invention, the object detection system for a semi-trailer-type vehicle comprises: an object detection device for detecting an object; a tilt detection device for detecting a tilt of a semi-trailer-type vehicle; and A position specification means for specifying a position of the object that has been detected by the object detection means, and correcting the position so that the inclination that has been detected by the inclination detection means is upright.

[0007] With this configuration, it is possible to accurately detect the position of another vehicle by performing a rotation-coordinate transformation using position coordinates, without using a separate module.

[0008] (2) According to the invention, the inclination detected by the inclination detection means is an inclination caused by rolling and pitching of the vehicle of the semi-trailer type.

[0009] With this configuration, it is possible to determine the position of another vehicle by performing a rotation-coordinate transformation on the roll and pitch controls using the position coordinates, without using a separate module.

[0010] (3) Preferably the tilt detection means is a gyro sensor which is provided via a power source of the vehicle of the articulated type when viewed from one side of the vehicle.

[0011] With this configuration, in which the tilt detection device is a gyro sensor located at the vehicle's center of gravity, it is possible to detect the tilt of the entire vehicle even more easily.

[0012] (4) Preferably the object detection means is provided at a front position of the semi-trailer-type vehicle and detects an object in front of the semi-trailer-type vehicle.

[0013] With this configuration, in which the object detection device is provided at a front position of the vehicle, it is possible to obtain information about what is in front of the vehicle even more easily and to improve object detection.

[0014] (5) Preferably the object detection means shall be at least one consisting of a radar, a sonar and a camera.

[0015] With this configuration, it is possible to correct the detected position of an object, which is detected by radar, sonar or camera, according to the actions of the vehicle body.

[0016] (6) According to the invention, a vehicle of the semi-trailer type according to claim 5 is specified, which is equipped with the object detection system according to the invention for a vehicle of the semi-trailer type.

[0017] With this configuration, it is possible to correct any shift in the detected position caused by actions of the vehicle body and to track the selected target even more accurately.

[0018] (7) Furthermore, according to the invention, a position correction method according to claim 6 is specified.

[0019] With this configuration, it is possible to accurately detect the position of another vehicle by performing a rotation-coordinate transformation using position coordinates, without using a separate module. Advantageous effects of the invention

[0020] According to the present invention, it is possible to provide an object detection system for a semi-trailer-type vehicle and a semi-trailer-type vehicle which are able to correct an inclination using a simple configuration. Brief description of the drawings Fig. Figure 1 is a graphic showing a right side surface and a control block of a semi-trailer-type vehicle according to an embodiment of the present invention. Fig. Figure 2 is a graphic showing an example of a situation in which the embodiment is assumed. Fig. Figure 3 is a graphic that shows an example of a radar's coordinate space. Fig. Figure 4 is a graphic showing how a detected position is corrected according to a roll angle and a pitch angle of a vehicle body. Fig. Figure 5 is a flowchart that shows a process for correcting the detected position. Description of embodiments

[0021] The following describes a semi-trailer-type vehicle according to an embodiment of the present invention with reference to the drawings. In the description, a direction in the direction of travel of the semi-trailer-type vehicle is referred to as a forward-reverse direction, a left-right direction when a driver is operating the vehicle is referred to as a vehicle width direction (or a left-right direction) of the semi-trailer-type vehicle, and the right and left sides, when viewed from the driver's perspective, are accordingly referred to as a right direction and a left direction. Vehicle of the articulated type

[0022] Fig. Figure 1 is a graphic showing a right-side surface and components, such as ECUs (electronic control units) for controlling various units, of a vehicle of type 1 according to an embodiment of the present invention.

[0023] The vehicle of type 1, a semi-trailer type, is a two-wheeled touring motorcycle suitable for long-distance travel. However, the present invention is applicable to various types of semi-trailer type vehicles, including two-wheeled motorcycles of other designs. Furthermore, the present invention is applicable not only to vehicles using an internal combustion engine as a power source, but also to electric vehicles using a motor as a power source. Hereinafter, the vehicle of type 1 may also be referred to as vehicle 1.

[0024] The vehicle 1 is equipped with a drive unit 2 located between a front wheel FW and a rear wheel RW. In the present embodiment, the drive unit 2 comprises a horizontal motor with six opposed cylinders 21 and a gearbox 22. A driving force from the gearbox 22 is transmitted to the rear wheel RW via a drive shaft (not shown) and rotates the rear wheel RW.

[0025] The drive unit 2 is supported by vehicle body frames 3. The vehicle body frames 3 comprise a pair of left and right main frames, which are positioned to extend in an X direction. A fuel tank 5 and an air purification box (not shown) are provided across the main frames. An instrument panel MP, which displays various types of information to a driver, is provided in front of the fuel tank 5.

[0026] A head tube, which rotatably holds a steering axle (not shown) that is rotated by handlebars 8, is provided at the front side end positions of the main frames. A pair of left and right pivot plates are provided at the rear end sections of the main frames. The lower end sections of the pivot plates and the front end sections of the main frames are connected by a pair of left and right lower arms (not shown), and the power unit 2 is held by the main frames and the lower arms.

[0027] A pair of left and right seat rails, extending rearward, are also provided at the rear end sections of the main frames, and the seat rails support a seat 4a on which a driver can sit, a seat 4b on which a passenger can sit, a rear storage compartment, etc. The rear end sections of the seat rails and the swivel plates are connected by a pair of left and right subframes.

[0028] The front end sections of a rear swingarm (not shown), which extends in the forward-backward direction, are pivotally mounted by the pivot plates. The rear swingarm is pivotable in an up-down direction, and the rear wheel RW is mounted by a rear end section thereof. A muffler 6, which dampens the exhaust noise from the engine 21, is provided on one side of a lower section of the rear wheel RW. Left and right saddlebags are provided on the sides of an upper section of the rear wheel RW.

[0029] A front suspension mechanism 9, which holds the front wheel FW, is formed at the front end sections of the main frame. The front suspension mechanism 9 comprises an upper linkage, a lower linkage, a fork mounting element, a damping unit, and a pair of left and right front forks. Anterior structure

[0030] A headlight unit 11, which emits light forward from the vehicle 1, is provided at the front of the vehicle 1. In the present embodiment, the headlight unit 11 is a twin-eye type headlight unit comprising a right light emission unit 11R and a left light emission unit 11L, which are symmetrical. However, a single-eye type headlight unit, a triple-eye type headlight unit, or an asymmetric twin-eye type headlight unit can also be assumed. Additionally, a multi-eye type headlight unit comprising an even greater number of light emission units can also be assumed.

[0031] The front section of vehicle 1 is covered by a front cover 12 and the front side sections of vehicle 11 are covered by a pair of left and right side covers.

[0032] A disc 13 is provided above the front cover 12. The disc 13 is a windscreen that reduces the wind pressure experienced by the driver while driving and is made, for example, of a transparent resin element. A pair of left and right side mirror units 15 are provided on the sides of the front cover 12. The side mirror units 15 hold side mirrors (not shown) with which the driver can visually check the area behind them.

[0033] Detection units 16 and 17, which detect what is in front of the vehicle 11, are provided behind the front cover 12. In this example, the detection units 16 and 17 are provided at fixed positions relative to the main frame. In the present embodiment, the detection unit 16 is a radar (for example, a millimeter-wave radar). However, another type of sensor that can detect forward through the front cover 12, such as a sonar that performs ultrasonic distance measurement or a lidar that performs image detection and distance measurement using laser light, can be used. If the detection unit 16 detects an obstacle located in front of the vehicle 1, the instrument panel MP can display a warning, for example, to alert the driver.The detection unit 16 is provided in a central position of the front cover 12 between the left and right headlight units.

[0034] In the present embodiment, the detection unit 16 is provided behind a trim element. Due to the presence of the trim element, the detection unit 16 is not visible in a front view of the vehicle 1, thus preventing the vehicle 1's external appearance from being compromised. The trim element is made of a material that allows electromagnetic waves to pass through it, such as a resin.

[0035] The detection unit 16 is located on the central section of the front cover 12. Therefore, the detection unit 16 can cover a wider detection area extending to the left and right in front of the vehicle 1, and can detect what is in front of the vehicle 1 with fewer defects. The single detection unit 16 also makes it possible to monitor the left and right sides in front of the vehicle 1 equally. Therefore, such a configuration is particularly advantageous when only one detection unit 16 is provided, instead of multiple detection units 16.

[0036] The detection unit 17 is a camera that captures an image of what is in front of it. The detection unit 17 can also be referred to as a camera 17. A section of the cladding element positioned in front of the camera 17 is provided with an opening, or the section positioned in front of the camera 17 is formed from a transparent element. The camera 17 captures an image of what is in front of it through the opening or the transparent element.

[0037] Next, the control unit 100 will be described. Vehicle 1 is equipped with the control unit 100, which comprises multiple ECUs 110 to 160 connected via a network within the vehicle to enable communication. Each ECU includes, for example, a processor, typically a CPU, a storage device, such as semiconductor memory, and an interface with an external device. The storage device stores, for example, a program executed by the processor and data used by the processor for processing. Each ECU can include, for example, multiple processors, multiple storage devices, and / or multiple interfaces.

[0038] The following describes the functions and such of ECUs 110 to 160. It should be noted that the number of ECUs and their functions may be appropriately designed for vehicle 1 and may be subdivided or integrated compared to those in the present embodiment.

[0039] The ECU 110 performs control for automated driving, in particular adaptive cruise control (ACC) of the vehicle 1. In the ACC according to the present embodiment, the acceleration and deceleration of the vehicle 1 are controlled automatically. In the example of a control system described below, the speed and acceleration and deceleration of the vehicle are controlled such that the vehicle follows the vehicle ahead, which is detected by the detection unit 16 (radar 16) and / or the detection unit 17 (camera 17), maintaining a defined interval between them. The ECU 110 implements ACC by cooperating with another ECU, such as an ECU 110.It should be mentioned that in this example, when a manual brake operation is performed, the ACC is canceled and a non-ACC manual operation is resumed.

[0040] The ECU 120 controls the detection units 16 and 17, which detect the environment around vehicle 1, in particular a target in front of vehicle 1, and process the results of the detection. A target that can be detected in front of the vehicle is primarily the vehicle ahead, and information relating to the vehicle ahead, especially information including its direction and distance relative to vehicle 1, is referred to as information about a vehicle ahead. The detection units 16 and 17 for acquiring such information about a vehicle ahead, and the ECU 120 that controls the detection units 16 and 17, can also be collectively referred to as detection units, forward monitoring devices, or forward monitoring units. Detection unit 17 is a camera that captures an image of what is in front of vehicle 1.In the present embodiment, the detection unit 17 is positioned above the detection unit 16 within the fairing element of the vehicle 1. By analyzing the image captured by the camera 17, it is possible, for example, to extract the contour of the target. Furthermore, it is also possible, for example, by analyzing the characteristics of the detected contour, to specify the type of vehicle detected. Vehicle types include, for example, a two-wheeled vehicle and a four-wheeled vehicle. With regard to a four-wheeled vehicle, it is also possible, for example, to detect its size based on the distance detected by the radar 16 and to specify the vehicle as a standard vehicle or a large vehicle.

[0041] In addition to its function as a forward monitoring unit, the ECU 120 processes a signal detected by a gyro sensor 30 to specify the vehicle body's tilt. The gyro sensor 30 is preferably located at the vehicle body's center of gravity and detects at least one tilt about a pitch axis and one tilt about a roll axis. The roll axis extends in a direction of travel, and the pitch axis extends in the direction of the vehicle body's width and is orthogonal to the roll axis.It should be noted that if a device, such as a motor (i.e., the drive source) or an accessory, is located at the center of gravity, the gyro sensor 30 only needs to be positioned near the center of gravity of the vehicle body. This is among the possible positions where the gyro sensor 30 can be located, and is preferably located in the position closest to the center of gravity. Conveniently, the gyro sensor 30 can be located near the center of gravity, for example, above the drive source.

[0042] The detection unit 16 is, for example, a millimeter-wave radar and detects a target around the vehicle 1 in order to measure its direction and distance. In the present embodiment, the radar 16 is configured to point forward, but can also be configured to point in another direction. The radar 16 scans a predetermined area extending in front of the vehicle in the width direction to detect a target within the scan area. The scan area is roughly fan-shaped, with the radar 16 located at its corner. The ECU 120 controls the camera 17 and the radar 16 and, for example, performs information processing on the results of a detection.

[0043] The ECU 130 controls the drive unit 2. The drive unit 2 is a mechanism that outputs driving force to rotate a driven wheel of the vehicle 1 and includes, for example, the motor 21 and the transmission 22. The ECU 130 controls the output of the motor 21 according to the driving operation of a driver (an acceleration operation or a multi-speed operation), which is detected by an operation detection sensor 8a of a throttle grip, which is provided, for example, on the handlebars 8. When the driving state of the vehicle 1 is ACC (automated driving), the ECU 130 automatically controls the power unit 2 according to an instruction from the ECU 110 to control the speed, acceleration, and deceleration of the vehicle 1.Furthermore, in ACC mode, the ECU 130 can shift the gear level of the transmission 22 based on information such as the vehicle speed, which is detected by a vehicle speed sensor 7c.

[0044] The ECU 140 controls braking devices 10. The brakes 10 are, for example, disc brake devices and are provided accordingly for the wheels of the vehicle 1, and decelerate or stop the vehicle by counteracting the rotation of the wheels. The ECU 140 controls the action of the braking device 10 according to a driving operation by the driver (brake operation), which is detected by an operation detection sensor 7b provided at a brake pedal. When the vehicle 1 is in an ACC driving state, the ECU 140 automatically controls the braking device 10 according to an instruction from the ECU 110 to control the deceleration and stopping of the vehicle 1. The braking device 10 can also perform an action to hold the vehicle 1 in a stopped state.

[0045] The ECU 150 controls an input device 153 and an output device, which includes a speech output device 151 and a display unit 152. The input device 153 receives information entered by the driver. In the example in Fig. The input device 153 comprises a selection and input button (also referred to as a cross button) 152a and an ACC instruction button 153b. The voice output device 151 is a voice output device and notifies the driver of information by voice. It should be noted that in the case of a two-wheeled vehicle, it can be difficult to hear speech. Therefore, a picture display device can be used instead. The display unit 152 notifies the driver of information by displaying a picture. The display unit 152 is provided in the instrument panel MP and is used in particular to determine the tracking target and is used in the ACC mode in this example. The input device 153 is preferably a set of switches arranged such that the driver can operate the switches while holding the handlebars and is used to input a command to the vehicle 1.It is possible to switch the ACC mode ON and OFF by pressing button 153. For example, if button 153b is pressed in a non-ACC mode (a manual driving mode), the mode is switched to ACC mode, and if button 153b is pressed in ACC mode, the mode is switched back to non-ACC mode. In ACC mode, vehicle 1 follows the vehicle ahead, which is detected by radar 16. It should be noted that the display unit 152 is not necessarily provided in the instrument panel MP and may, for example, be provided in a head-up display, a windshield mirror, or a visor.

[0046] The ECU 160 controls communication carried out by a communication device 160a. This communication can, for example, be communication with a server device to acquire map information from a navigation device (not shown), or it can be receiving signals from a satellite using a GPS antenna. It should be noted that the control configuration, which is in Fig. Figure 1 is an example, and the objectives controlled by an ECU can be further subdivided or, conversely, integrated. Additionally, other components, such as lights, can be included in the objectives of an automatic control system. High-speed chase in ACC mode

[0047] Next, a pursuit run conducted by vehicle 1 in ACC mode will be described. Fig. Figure 2 shows an example of such a situation, viewed from above. Vehicle 1 is a two-wheeled vehicle capable of driving in ACC mode, and Vehicle 202 is a four-wheeled vehicle traveling in the lane close to Vehicle 1. Vehicle 201 is a two-wheeled vehicle traveling in the same lane as Vehicle 1. Vehicle 1 is equipped with Radar 16, which detects a target in front of Vehicle 1, and a detectable area of ​​Radar 16 is a scan area 210. Although Radar 16 has a limit regarding detectable distance, such a limit is not present in Fig. 2 not specifically shown.

[0048] In the situation which arises in Fig. As shown in Figure 2, both vehicle 201 and vehicle 202 are within the scan range of radar 16. When vehicle 1 performs a pursuit in ACC mode, it can follow a selected vehicle or a vehicle positioned at a pre-specified location as a pursuit target vehicle. For the vehicle designated as the pursuit target, vehicle 1's ECU 110 maintains the speed and performs acceleration or deceleration control, if necessary, to maintain a constant distance to the pursuit target vehicle—for example, the distance at the time an ACC command was issued. The distance to be maintained could be a distance L between the vehicles. However, in this example, the distance is set to a distance Zp in the direction of travel.Even if the direction of the pursued vehicle changes slightly, if the vehicle can be identified as the same, Vehicle 1 continues to follow it. However, if the pursued vehicle deviates from scan area 210 or suddenly changes its position so that it can no longer be identified as the same vehicle, Vehicle 1 ceases pursuit. At this time, it is dangerous, especially on highways, because the acceleration is quickly cut and Vehicle 1 suddenly decelerates due to the lost (missing) pursued vehicle. Therefore, to avoid sudden deceleration even in such a case, it is preferable to notify the driver of the loss and to initiate a moderate deceleration or maintain speed unless the approaching target is detected ahead. Target specification by radar

[0049] First, an example of a coordinate system for specifying the position of the target detected by the radar is given, with reference to Fig. 3 will be described. Fig. 3 is an origin O, the origin of a space that specifies the position of the target detected by the radar 16 (and the camera 17), and can, in particular, be the intersection of a downward vertical line from a central section of the radar 16 and the ground when the vehicle 1 is upright. The Y-axis is an axis that connects the origin O and a center point Or of the radar 16 (referred to as a radar origin) when the two-wheeled vehicle is upright, and corresponds to a height component. The position of the center point of the radar 16 is designated by Yor. It should be noted that Yor is the height of the radar 16 from the ground when the two-wheeled vehicle is upright. It should be noted that Yor is an axis that extends from the origin O to the central line of the scan area in the vehicle width direction of the radar 16 when the two-wheeled vehicle is upright.The Z-axis is an axis parallel to an axis of the vehicle, extending from the origin O in the forward-backward direction, and represents a component in the depth direction as viewed by the driver. The X-axis is orthogonal to the Y-axis and the Z-axis and represents a component in the width direction of the vehicle.

[0050] In this example, radar 16 emits a radio wave (beam) in a certain direction and detects the distance to the target based on the reflection from it. The direction is represented by an azimuth angle α and an elevation angle β. An axis passing through the radar origin Or and parallel to the Z-axis is called the Z'-axis, and an axis passing through the radar origin Or and parallel to the X-axis is called the X'-axis (not shown). The azimuth angle α is the angle formed by a projection line 301, when the radio wave beam is projected to be orthogonal to the X'-Z' plane, and the Z'-axis. The elevation angle β is the angle formed by the projection line 301 and the radio wave beam.

[0051] For example, a target at position P is detected by radar 16 and the position is specified as (distance L, azimuth angle α, elevation angle β). In such a case, the position can be transformed to Cartesian coordinates (Xp, Yp', Zp) with respect to the radar origin Or using the following equations. Xp=L⋅cos β⋅sin Yp'=L⋅sin β⋅sin α Zp=L⋅cos β⋅cos α

[0052] By adding the height Yor of radar 16 to the Y component, the coordinates of the three-dimensional Cartesian coordinates (Xp, Yp, Zp) can be transformed with respect to the origin O, which is a point immediately below radar 16 of the two-wheeled vehicle, which is upright, i.e. a point near the grounding point of the front wheel of the two-wheeled vehicle. Xp=L⋅cos β⋅sin α Yp=L⋅sin β⋅sin α+Yor Zp=L⋅cos β⋅sin α

[0053] The position of the target detected by radar 16 is specified in three-dimensional space with respect to vehicle 1, and this specified position is stored as a detected position. Radar 16 scans the scan area in front of the target while the azimuth angle α and the elevation angle β are changed, and the position of the detected target is updated accordingly. It should be noted that scanning does not necessarily have to be performed in the elevation-angle direction and can be performed solely in the azimuth-angle direction. Conversely, by widening the scan area in the elevation-angle direction, objects in front of vehicle 1 are more likely to be included in the detection area, even if vehicle 1 is tilted forward or backward.

[0054] As described above, the target's position, specified by radar 16, is a relative position with respect to vehicle 1. Because the relative position is specified, it is simple to implement adaptive cruise control (ACC) to follow the vehicle ahead, as it is only necessary to maintain the relative position. On the other hand, due to changes in orientation, such as left-right tilt (rolling) and forward-backward tilt (pitching), which are characteristics of two-wheeled vehicles, the coordinate space is also tilted with respect to the vehicle body, and the position of the vehicle ahead shifts rapidly. Fig. Figure 4 represents a tilt in the left-right direction and a tilt in the forward-backward direction. Fig. Figure 4A is an example, a graphic focusing on radar 16 in a front view of vehicle 1. The origin O is the grounding point of the front wheel FW, and radar 16 is tilted to radar 16' by pivoting about origin O through an angle θ (referred to as a roll angle). Example 4B shows vehicle 1 viewed from the left. In this case, radar 16 is tilted to radar 16'' by pivoting about an origin O' of vehicle 1, instead of the origin O of coordinate space, through an angle Ψ (referred to as a pitch angle). Naturally, each tilt occurs not only in one direction but also in the opposite direction to the direction shown in the figure. Correction of the position coordinates of a target

[0055] Therefore, in the present embodiment, the coordinates of the target detected by the radar 16 are corrected to return through a roll angle of θ and a pitch angle of Ψ. Fig. Figure 5 shows an example of a processing operation performed to correct the coordinates of the target detected by radar 16 (referred to as radar coordinates). This procedure is performed, for example, by ECU 120. However, this procedure can also be performed by another ECU, such as ECU 110. First, ECU 120 detects the instantaneous tilt of the vehicle body using gyro sensor 30 (S501). The detected tilt includes at least a roll angle and a pitch angle. Next, ECU 120 detects the target using a sensor, namely radar 16, and detects its coordinates (S503). The coordinates detected for this point can be polar or Cartesian. Polar coordinates are transformed to Cartesian coordinates, as described in the example above.In the case of Cartesian coordinates, the origin of the coordinates is also transformed to be moved to the origin O, as shown in . Fig. 3, etc., if necessary. Next, the ECU 120 corrects the coordinates of the target detected by radar 16 (S505). Finally, the ECU 120 updates the target's position information with the corrected coordinates (S507) and completes processing.

[0056] The correction processing in step S505 will be described here. As with reference to Fig. As described in section 4, the roll angle θ and the pitch angle Ψ are angles with respect to different rotation axes. Therefore, in a strict sense, a correction is necessary when considering the rotation axes. However, the distance by which radar 16 moves due to a pitch is sufficiently smaller than the distance measured by radar 16. Therefore, it can be considered that the accuracy will not be significantly reduced even when correcting for a displacement about the origin O resulting from the pitch angle Ψ. Therefore, such a simplified correction will be described in this example.

[0057] Correcting the roll angle θ is a rotation transformation performed to convert the angle back to the roll angle θ. Therefore, if the coordinates before a correction are denoted as (X, Y, Z) and the coordinates after a correction are denoted as (X', Y', Z'), a correction can be performed using Equation 1. X'=X⋅cos(−θ)−Y⋅sin(−θ)Y'=X⋅sin(−θ)+Y⋅cos(−θ)Z'=Z

[0058] According to a simple procedure, a correction of the pitch angle Ψ is also performed as a rotation transformation to reduce the angle by the pitch angle Ψ. Therefore, if the coordinates before a correction are denoted as (X', Y', Z') and the coordinates are denoted as (X'', Y'', Z''), a correction can be performed using equations 2. X'' =

[0059] These equations can be combined into equation 3. X"=X⋅cos(−θ)−Y⋅sin(−θ)

[0060] The coordinates obtained in this way (X'', Y'', Z'') are the coordinates after a correction. Although linear equations for transforming the corresponding coordinate are shown in this example, a transformation can of course be performed that uses a two-level matrix to correct the inclination angles.

[0061] If the pitch angle Ψ is strictly corrected, (X'', Y'', Z'') are calculated from (X', Y', Z') to correct the pitch angle Ψ about the center of gravity O' (see Example 4B in Fig. 4), viewed from the side of vehicle 1, assuming that the center of gravity O' is the center of pitch rotation. For example, the origin O is shifted to O', a rotation correction is performed with respect to the origin, and the origin O' is shifted back to the origin O. It should be noted that a shift / translation can be implemented using an affine mapping, and therefore this correction can also be implemented using a two-stage matrix to correct the roll angle θ and the pitch angle Ψ.

[0062] The roll angle and pitch angle can be corrected as described above. As a result, it is possible to prevent the position of the target detected by the radar, especially the vehicle ahead, from changing rapidly due to the roll or pitch of vehicle 1, and to avoid losing (missing) the tracking target due to changes in the orientation of vehicle 1.

[0063] The position of the preceding vehicle, which has been corrected in this way, is updated at predetermined time intervals, for example, intervals ranging from several tenths of milliseconds to 100 milliseconds. The object's identity is determined based on its proximity and a predicted movement of the detected position at each update or image captured by camera 17. The preceding tracking target vehicle is identified, and its position is specified. Given that the specified preceding vehicle is the tracking target, ECU 110 controls, for example, the acceleration device, the brakes, etc., and therefore it is possible to drive while maintaining a preset distance to the preceding tracking target vehicle.The distance can be set, for example, to the distance to the tracking target when the tracking target is selected and an instruction is given to start ACC. Even if the tracking target detected by radar 16 is lost during a pursuit, ACC will be terminated at that point. In this way, the position of the tracking target detected by radar 16 is corrected according to the orientation of vehicle 1, and ACC is performed based on the corrected position, thus enabling a more precise and continuous pursuit. [Other embodiments]

[0064] Although both the roll angle and the pitch angle are corrected in the embodiment above, only the pitch angle needs to be corrected. In such a case, the roll angle can be the same as in the embodiment above. On the other hand, the pitch angle can be corrected by substituting X', Y', and Z' on the right-hand side of equations 2, which are used to obtain the corrected coordinates (X'', Y'', Z'') with X, Y, and Z, respectively.

[0065] Furthermore, although a change in position in the left-right direction (the angle of this change is called a yaw angle, and a movement that causes this change is called a yaw or yaw action) is left unchanged in the above embodiment, such a change can be corrected. As shown in Fig. In the present embodiment, the radar 16 is mounted on an element extending forward from the main frame, and its position relative to the main frame is fixed. However, in the case of a vehicle type without a front cover, the radar 16 can be mounted on the grab handles, and its orientation can be changed by operating the grab handles. In such a case, the orientation of the vehicle 1 and the orientation of the grab handles are different, and therefore the change in position detected by the radar 16 resulting from such operation of the grab handles can be corrected.

[0066] In such a case, the difference between the direction in which the main frame points and the direction in which the handlebars point is the yaw angle that needs to be corrected. In this case, the state in which the steering axis of the handlebars is straight ahead is used as a reference (the yaw angle is 0 degrees), and the rotation angle of the steering axis relative to the head tube attached to the frame is detected as the yaw angle. Therefore, a detection unit (for example, a rotation encoder) is provided for this purpose near the steering axis. The yaw angle is measured on the XZ plane in the coordinate space in Fig. 3 corrected if the vehicle 1 in Fig. 1, for example, viewed from above. Since the head tube is slightly tilted backwards, the tilt caused by operating the handles includes not only a yaw component but also a certain amount of a roll component. However, only the yaw angle, which is the main component, is considered in this example. Although the steering axis and the origin O are also slightly offset from each other, such an offset becomes sufficiently small relative to the detection distance of the radar 16. Therefore, the yaw angle is also transformed by a rotation about the origin O into Fig. 3 corrected.

[0067] Therefore, if only the yaw angle needs to be corrected, coordinates are calculated using equations 4 as shown below, where the coordinates detected by radar 16 are (X, Y, Z), the corrected coordinates are (X''', Y''', Z'''), and the yaw angle is φ. X''' = By applying (X'', Y'', Z'') in equations 3 to X, Y and Z in equations 4 it is possible to obtain coordinates in which the yaw angle (the steering angle of the handles) is also corrected in addition to the pitch angle and the roll angle (5). " Y'''=(X⋅sin(−θ)+Y⋅cos(−θ))⋅sin(−ψ)+(X⋅sin(−θ)+Y⋅cos(−θ))⋅cos(−ψ) Z'''=(X⋅cos(−θ)−Y⋅sin(−θ))⋅sin(−φ)−(Z⋅cos(−ψ)+Z⋅sin(−ψ))⋅cos(−φ)

[0068] These equations 5 can also be realized using a three-stage matrix transformation. Furthermore, it is possible to correct a desired change in state in the roll angle, pitch angle, or yaw angle by combining these equations.

[0069] In this embodiment, the coordinate system for the position detected by the radar is a Cartesian coordinate system. However, a polar coordinate system can also be used, which specifies the position by the distance, azimuth angle, and altitude angle of an object. In such a case, a displacement caused by the pitch and yaw angles can be corrected by subtracting the pitch angle from the altitude angle and the yaw angle from the azimuth angle. A displacement caused by the roll angle affects both the altitude angle and the azimuth angle. Therefore, the simplest way to transform the polar coordinate system into a Cartesian coordinate system is to perform a rotational transformation of the Cartesian coordinate system to remove the roll angle, and then convert the Cartesian coordinate system back to the polar coordinate system.

[0070] As described above, equations 5, etc., are simple equations that allow the centers of rotation of the pitch and yaw angles and the center of a rotation transformation for correction to be shifted relative to each other. To achieve higher accuracy for each transformation, the shift from the actual axis of rotation can be adjusted by performing a translation transformation when a rotation transformation is performed for correction. Such simple expressions are used because the distance to the target detected by radar 16 is large, and therefore the shift caused by a change in the orientation of radar 16 is particularly large, whereas the shift in the radar position is sufficiently small in comparison.

Claims

[1] Object detection system for a vehicle (1) of the articulated type, comprising: an object detection means (16, 17) for detecting a tracking target object; wherein the object detection means (16, 17) is provided on a handle (8) which is rotatable on a body of the vehicle (1); a tilt detection means (30) for detecting a tilt of a vehicle (1) of the articulated type; and a steering angle detection means for detecting a steering angle of the handle (8) of the body, characterized by a position specification means (120) for specifying a position of the tracking target object, which has been detected by the object detection means (16, 17), and correcting the position so that the inclination, which has been detected by the inclination detection means (30), is upright, and the steering angle of the handle (8), which is detected by the steering angle detection means, is directed straight ahead, a control device (110) for carrying out acceleration or deceleration control in order to maintain the distance to the tracking target object at a constant distance, and that the inclination detected by the inclination detection means (30) is an inclination caused by rolling of the vehicle (1) of the semi-trailer type and an inclination caused by pitching of the vehicle (1) of the semi-trailer type. [2] Object detection system for a vehicle (1) of the semi-trailer type according to claim 1, characterized by, that the tilt detection means is a gyro sensor (30) which is provided above a drive source (21) of the vehicle (1) of the semi-trailer type when viewed from one side of the vehicle (1). [3] Object detection system for a vehicle (1) of the semi-trailer type according to claim 1 or 2, characterized by , that the object detection means (16, 17) is provided at a front position of the vehicle (1) of the semi-trailer type and detects an object in front of the vehicle (1) of the semi-trailer type. [4] Object detection system for a semi-trailer-type vehicle according to one of claims 1 to 3, characterized by , that the object detection means (16, 17) is at least one consisting of a radar (16), a sonar and a camera (17). [5] Semi-trailer-type vehicle, characterized by , that it is equipped with the object detection system for a vehicle (1) of the semi-trailer type according to one of claims 1 to 4. [6] Position correction procedure, which is carried out by an object detection system for a vehicle (1) of the articulated type, and comprises: Detecting a tracking target object using an object detection device (16, 17), wherein the object detection device (16, 17) is provided on a handle (8) which is rotatable on a body of the vehicle (1); Detecting an inclination of a vehicle (1) of the articulated type using an inclination detection device (30); Detecting a steering angle (8) of the body, Specifying a position of the tracking target object, which is detected by the object detection means (16, 17), and correcting the position so that the inclination, which is detected by the inclination detection means (30), is upright, and the steering angle of the handlebar (8), which is detected by the steering angle detection means, is directed straight ahead, and Performing acceleration or deceleration control to maintain a constant distance to the tracking target object, characterized by , that the inclination detected by the inclination detection means (30) is caused by an inclination caused by rolling of the vehicle (1) of the semi-trailer type and an inclination caused by pitching of the vehicle (1) of the semi-trailer type.

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