JP7312555B2 - Obstacle detection device for construction vehicles - Google Patents

Description

The present invention relates to an obstacle detection device for construction vehicles.

For example, when rolling the rollers close to a curb, the driver drives the vehicle while watching the rolling surface around the curb, and thus tends to neglect the direction of travel. As a result, accidents involving contact with surrounding workers are likely to occur, particularly when the vehicle is moving backwards.

To address this problem, there are known alarm devices that use radio waves or ultrasonic waves to issue an alarm when a person or object is detected at a certain distance, or an automatic stop device that automatically stops a vehicle (see, for example, Patent Documents 1 to 3). Patent Document 1 describes an emergency stop device that includes a magnetic field generator mounted on a vehicle, an IC tag attached to a worker, a detection device that detects radio waves emitted from the IC tag, and an engine stop device that stops the vehicle when the detection device detects the radio waves. Patent Document 2 describes a stopping system including a trigger signal output means mounted on a vehicle, an ID tag worn by a worker, a receiving section for receiving an ID number output by the ID tag, and stopping means for stopping the vehicle when the receiving section receives the ID number. Patent Literature 3 describes an ultrasonic obstacle detection device.

JP 2016-153558 A JP 2017-10483 A JP-A-2006-17496

Here, since the compaction roller is often used in a narrow area peculiar to road construction, if the detection range in the vehicle width direction is increased more than necessary, there will be a problem that an alarm will be sounded or the vehicle will stop frequently even though there is no danger of collision with curbs, utility poles, colored cones, etc. on the boundary between the roadway and the sidewalk.

Furthermore, when the vehicle moves forward or backward while turning, the travel route of the vehicle differs from that when the vehicle travels straight. As a result, there is a problem that the vehicle stops unnecessarily, an alarm sounds, and an obstacle that should be detected cannot be detected.

SUMMARY OF THE INVENTION The present invention was created to solve such problems, and it is an object of the present invention to provide an obstacle detection device for a construction vehicle that can be easily set to a desired detection range according to the travel route of the vehicle.

In order to solve the above-mentioned problems, the present invention is an obstacle detection device mounted on a construction vehicle, comprising: an object detection sensor that detects an obstacle within a predetermined range; and a control device that calculates an estimated travel route of the construction vehicle based on the turning radius of the construction vehicle and determines the presence or absence of an obstacle based on the detection result of the object detection sensor. is set asThe detection range is set to have a width dimension substantially the same as the vehicle width dimension of the construction vehicle when traveling straight, and is set such that the outer side of the detection range extends beyond the vehicle width so as to correspond to the outermost diameter of the construction vehicle when turning.It is characterized by

According to the present invention, since the detection range is set according to the estimated travel route calculated from the turning radius of the construction vehicle, a desired detection range can be set depending on whether the construction vehicle runs straight or turns.

In addition, according to the present invention, by setting the detection range to have a width dimension that is substantially the same as the vehicle width dimension, it is possible to recognize the presence of an obstacle only when there is a high possibility of colliding with the vehicle, and to take measures such as stopping the vehicle or issuing an alarm. As a result, useless vehicle stops and warnings can be avoided.

Also, when turning, the front-side outermost part of the vehicle travels outside the rear-side outermost part. According to the present invention, the range through which the front-side outermost part of the vehicle passes can be included in the detection range, so the obstacle can be detected more reliably.

Further, the present invention is characterized by comprising braking means for braking the vehicle when the control device determines that there is an obstacle.

According to the present invention, collisions with obstacles can be reduced, and the safety of surrounding workers can be ensured.

Further, the present invention is characterized in that the construction vehicle is a compaction roller, and the braking means is an HST brake acting on a closed circuit of a running pump and a running motor.

According to the present invention, by using the HST brake, it is possible to avoid excessive sudden stops and to reduce flatness defects such as dents on the asphalt paved road surface. In addition, it becomes easy to resume running after the vehicle stops.

Further, the present invention is characterized in that the timing at which the braking of the braking means is started changes according to the running speed of the vehicle.

Even when a worker temporarily enters the detection range and then immediately leaves the detection range, braking the vehicle reduces the work efficiency of the vehicle. On the other hand, for example, by changing the start timing of braking according to the limit braking distance of the vehicle, which changes according to the traveling speed, it is possible to brake the vehicle only when there is a high risk of collision according to the traveling speed, thereby reducing unnecessary vehicle stops.

According to the present invention, a desired detection range can be easily set according to the travel route of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the detection range of the obstacle detection apparatus with which the tire roller which concerns on 1st embodiment of this invention was mounted|worn, (a), (b) is a top view and a side view, respectively. 1 is a configuration block diagram of an obstacle detection device according to a first embodiment; FIG. 1 is a schematic hydraulic circuit diagram of a travel system including brake means; FIG. It is a graph which shows a brake start distance. It is a top view for demonstrating the subject of the obstacle detection apparatus which concerns on 2nd embodiment of this invention. It is a configuration block diagram of an obstacle detection device according to a second embodiment. FIG. 10 is a plan view showing a detection range when turning in the obstacle detection device according to the second embodiment. FIG. 11 is a plan view showing a detection range in the case of going straight in the obstacle detection device according to the second embodiment; FIG. 11 is a plan view showing an estimated travel route when turning in the obstacle detection device according to the third embodiment; FIG. 11 is a plan view showing a detection range when turning in the obstacle detection device according to the third embodiment.

[First embodiment]
An obstacle detection device 1 according to a first embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, an obstacle detection device 1 of the present invention is mounted on a construction vehicle such as a compaction roller that performs work while traveling at a low speed. FIG. 1 shows a case where an obstacle detection device 1 is mounted on a tire roller 10 that rolls an asphalt road surface or the like with a tire 11 . In FIG. 2, an obstacle detection device 1 includes a TOF (Time Of Flight) distance image sensor (3D distance sensor) 2 that measures distance from the time difference between projected light and reflected light, and a control device 3 that determines the presence or absence of an obstacle G based on the measurement data of the distance image sensor 2.

The distance image sensor 2 includes a light-emitting portion that emits projected light such as infrared rays, and a light-receiving portion that receives reflected light when the projected light hits an object. The distance to the object is measured by measuring the time from when infrared rays are sent from the light emitting part to when the reflected light is received by the light receiving part. The projection angle from the distance image sensor 2 is, for example, 95° in the horizontal direction and 32° in the vertical direction (symbol θ1 shown in FIG. 1(b)), and the projection cross section has a horizontally long rectangular shape. The image resolution is, for example, 64 pixels in the horizontal direction and 16 pixels in the vertical direction, for a total of 1024 pixels. The distance image sensor 2 is attached to the central portion in the vehicle width direction of the rear portion of the tire roller 10 so that the projection light is projected obliquely downward in the backward direction.

As for the detection range of the obstacle G, if the projection range of the projection light is set as the detection range as it is, that is, if the dimension L1 in the vehicle width direction is set wider than the vehicle width dimension of the tire roller 10, the obstacle G is recognized even though there is no danger of collision, and the vehicle stops uselessly. Therefore, the dimension L1 of the detection range 4 in the vehicle width direction (indicated by oblique lines in FIG. 1) is set substantially equal to the vehicle width dimension of the tire roller 10 in this embodiment. Since the distance image sensor 2 can measure the distance to the obstacle G, the controller 3 can determine whether or not the obstacle G exists within the detection range 4 set to the width of the vehicle based on the measurement data for each pixel, specifically the distance between the distance image sensor 2 and the obstacle G in the vehicle width direction. By using the distance image sensor 2 in this way, the dimension L1 of the detection range 4 can be kept constant over the vehicle front-rear direction. In other words, the detection range 4 can be easily set to a substantially rectangular range with one side having the dimension L1 in plan view as shown in FIG. 1(a). A dimension L2 of the detection range 4 in the longitudinal direction of the vehicle is appropriately set according to the commonly used running speed, and is set to, for example, about 3 meters in the present embodiment.

In addition, since the projection light from the distance image sensor 2 is projected obliquely downward in the backward direction, the horizontal angle θ2 of the projection light when viewed from above is in a range larger than 95°. Therefore, the distance L3 in the vehicle front-rear direction of the non-detection areas 5, 5 formed between the rear ends of the tire roller 10 and the detection area 4 can be kept small. That is, the undetected blind spots formed on both sides of the rear portion of the vehicle can be reduced.

The control device 3 is provided with braking means 6 for braking the vehicle when it is determined that there is an obstacle G within the detection range 4 . An example of the braking means 6 will be described. In FIG. 3, a running pump P driven by an engine (not shown) and a running motor M rotating a tire 11 (FIG. 1) are connected in series to form a closed hydraulic circuit U1. The running pump P is a swash plate type pump. The traveling pump P is connected to an oil passage T1 and an oil passage T2 for operating the swash plate. A two-position, three-port electromagnetic valve V1 is interposed in parallel with the traveling pump P between the oil passages T1 and T2.

When the engine is running, the electromagnetic valve V1 is at the right position in FIG. 3, and the oil passages T1 and T2 are not communicated with each other. Therefore, when the forward/reverse lever around the driver's seat is tilted toward the forward position while the engine is running, the swash plate operating oil flows from the oil passage T1 side to the oil passage T2 side and the swash plate tilts to one side. As a result, the pressure oil flows in one direction in the closed circuit U1, the traveling motor M rotates in one direction, and the vehicle moves forward. When the forward/reverse lever is tilted toward the reverse position, the swash plate operating oil flows from the oil passage T2 side to the oil passage T1 side, and the swash plate tilts to the other side. As a result, the pressure oil flows in the other direction in the closed circuit UI, the traveling motor M rotates in the other direction, and the vehicle moves backward.

When the engine is not running, the electromagnetic valve V1 is in the left position as shown in FIG. 3, and the oil passages T1 and T2 are in communication. A closed hydraulic circuit U2 is formed between the electromagnetic valve V1 and the traveling pump P, and no differential pressure is generated between the oil passages T1 and T2, so that the swash plate is positioned at the neutral position. As a result, an HST (Hydro Static Transmission) brake acts in the closed circuit U1.

The brake means 6 of the present embodiment utilizes this electromagnetic valve V1, and when an obstacle is detected during backward movement, the control device 3 outputs a brake signal to switch the electromagnetic valve V1 from the right position to the left position. As a result, even when the engine is running and the forward/reverse lever is tilted toward the reverse position, the swash plate is positioned at the neutral position, the HST brake is applied in the closed circuit U1, and the running motor M is stopped. Between the charge pump P1 built in the running pump P and the negative brake M1 built in the running motor M, an electromagnetic valve V2 is interposed for operating the negative brake M1 during parking.

The timing from when the control device 3 determines that there is an obstacle G to when it outputs the brake signal, that is, the timing at which the braking means 6 starts braking, is preferably changed according to the running speed of the vehicle. As shown in FIG. 4, the control device 3 compares the braking start distance S preset according to the running speed with the distance to the obstacle G existing in the detection range 4 measured by the distance image sensor 2, and outputs a brake signal to the electromagnetic valve V1 when the distance to the obstacle G becomes equal to or less than the braking start distance S.

The braking start distance S is set, for example, to a distance slightly larger than the limit braking distance T actually measured for the vehicle. In FIG. 4, the braking start distance S is set to about 0.5 m at 2 km/h, about 1 m at 4 km/h, about 1.6 m at 6 km/h, and about 2.4 m at 8 km/h. As the vehicle speed sensor 7 (FIG. 2) for detecting the running speed of the vehicle, there is a proximity sensor such as a rotary encoder for detecting the number of revolutions of the tires.

As described above, the obstacle detection device 1 for a construction vehicle, which includes the TOF distance image sensor 2 that measures the distance from the time difference between the projected light and the reflected light, and the control device 3 that determines the presence or absence of the obstacle G based on the measurement data of the distance image sensor 2, has the following effects.
(1) The TOF-type distance image sensor 2 can accurately measure the distance to the object, and therefore has excellent obstacle detection accuracy.
(2) Unlike the detection method using radio waves, there is no need to attach detection tags to surrounding workers, and costs can be reduced. In addition, the problem of forgetting to attach the detection tag does not occur, and obstacles can be reliably detected.
(3) By using the distance image sensor 2, it is possible to easily set the desired detection range 4, such as setting the detection range 4 to the width of the vehicle.

The distance image sensor 2 is provided so that the projected light is projected obliquely downward in the traveling direction of the vehicle, and the control device 3 determines the presence or absence of an obstacle within the range of the projected light, which has a width dimension L1 substantially equal to the width dimension of the vehicle and has a substantially rectangular shape in a plan view.
(1) By making the detection range 4 substantially rectangular in plan view with a width dimension L1 that is substantially the same as the vehicle width dimension, it is possible to recognize the presence of an obstacle G only when there is a high possibility of colliding with the vehicle, and to take measures such as stopping the vehicle or sounding an alarm. As a result, useless vehicle stops and warnings can be avoided.
(2) By projecting the projection light obliquely downward in the traveling direction of the vehicle, it is possible to increase the horizontal angle θ2 of the projection light in a plan view. As a result, the distance L3 of the non-detection range 5 can be kept small, and the non-detection blind spots formed on both sides of the rear portion of the vehicle can be reduced.

When the control device 3 determines that there is an obstacle G, if the vehicle is provided with the braking means 6 that brakes the vehicle, collisions with the obstacle G can be reduced, and the safety of surrounding workers can be ensured. In particular, if the vehicle is stopped by braking without stopping the engine, there is no need to restart the engine when resuming work.

In particular, in the pressure roller such as the tire roller 10, if the brake means 6 is an HST brake that acts on the closed circuit U1 of the running pump P and the running motor M, excessive sudden stopping can be avoided compared to the case where the engine is stopped. In addition, the operation of resuming traveling is facilitated.

If the timing for starting the braking of the braking means 6 is changed according to the running speed of the vehicle, the following effects can be obtained. Even when a worker temporarily enters the detection range 4 and then immediately leaves the detection range 4, if the vehicle is braked, the work efficiency of the vehicle is reduced. On the other hand, for example, by changing the start timing of braking according to the limit braking distance T of the vehicle that changes with the traveling speed, the vehicle can be braked only when the possibility of collision is high according to the traveling speed, and useless stopping of the vehicle can be reduced.

The preferred embodiments of the present invention have been described above. In the present embodiment, the brake means 6 for braking the vehicle when it is determined that there is an obstacle G is provided. Also, the brake means 6 and the alarm may be used together. Also, the distance image sensor 2 may be attached to the front portion of the vehicle to detect the forward direction of the vehicle.

[Second embodiment]
Next, a construction vehicle obstacle detection device according to a second embodiment of the present invention will be described. FIG. 5 is a plan view for explaining problems of the obstacle detection device according to the second embodiment of the present invention. As shown in FIG. 5, when there is a wall W at the construction site, there is a case where the tire roller (construction vehicle) 10 is rotated while moving backward, and the work of rolling a position near the wall W is carried out. For example, when the tire roller 10 turns at a predetermined travel steering angle, an estimated travel route 21 (details will be described later) along which the tire roller 10 travels can be determined according to the rotation radius of the tire roller 10 .

At this time, as shown in FIG. 5, if both sides in the width direction of the detection range 4 for detecting obstacles remain parallel to the side portions of the tire roller 10, a deviation occurs between the estimated travel route 21 and the detection range 4. Therefore, in this configuration, although the tire roller 10 turns without contacting the wall W, the detection range 4 detects the wall W as an obstacle, so there is a problem that an alarm sounds or the vehicle stops. Also, in this configuration, the obstacle G on the inner wheel side is not included in the detection range 4 even though it is included in the estimated travel route 21, so it is not detected, and there is a risk that the vehicle and the obstacle G will come into contact with each other. In other words, in this configuration, there are problems such as the vehicle stopping or sounding an alarm unnecessarily, and on the other hand, the obstacle G that should be detected cannot be detected.

Therefore, as shown in FIG. 6, an obstacle detection device 1A according to the second embodiment is mainly composed of a distance image sensor 2, a control device 3, braking means 6, a vehicle speed sensor 7, and an angle sensor 8. An obstacle detection device 1A according to the second embodiment mainly differs from the first embodiment in the configuration of the control device 3 and the provision of an angle sensor 8. FIG. In the second embodiment, the description will focus on the parts that are different from the first embodiment.

The angle sensor 8 is a sensor that detects the steering angle (rudder angle) of the front tires 11 . As the angle sensor 8, for example, a steering angle sensor installed on the steering shaft of the tire roller 10 can be used. A steering angle signal detected by the angle sensor 8 is transmitted to the control device 3 . The angle sensor 8 may be configured to detect the steering angle of the tire 11 from the amount of expansion and contraction of the cylinder when the steering mechanism is provided with a steering cylinder.

As shown in FIG. 6, the control device 3 includes estimated travel route calculation means 31 and detection range calculation means 32 in addition to the configuration of the control device 3 described in the first embodiment. The estimated travel route calculation means 31 is means for calculating the rotation radius of the tire roller 10 and the estimated travel route 21 based on the steering angle signal transmitted from the angle sensor 8 .

In the present embodiment, the estimated running path 21 of the tire roller 10 shown in FIG. 7 means the trajectory that the trailing edge 21a passes after t seconds when the tire roller 10 moves forward or backward. The time t may be set as appropriate, and is set between 3 and 10 seconds, for example. That is, the estimated travel route 21 is an area surrounded by the first virtual line 21b and the second virtual line 21c.

The dimension of the rear end portion 21a of the tire roller 10 is the same as the width dimension L1 of the tire roller 10 (see FIG. 1(a)). Here, the portion at the left end and the rear end in the traveling direction of the vehicle is defined as the first corner portion 10a, and the portion at the right end and the rear end in the traveling direction is defined as the second corner portion 10b. The first imaginary line 21b is the turning radius R1 of the trajectory of the first corner portion 10a, which is calculated based on the steering angle (for example, the steering angle α) of the front tire 11, the wheelbase, and the like. The second imaginary line 21c is the turning radius R2 of the locus of the second corner portion 10b, which is calculated based on the steering angle (for example, the steering angle α) of the front tire 11, the wheelbase, and the like.

As shown in FIG. 8, when the tire roller 10 travels straight, the turning angle of the front tire 11 is 0°, so the estimated travel route calculation means 31 calculates the estimated travel route 21 so that the first virtual line 21b and the second virtual line 21c are parallel along the vehicle width from the first corner 10a and the second corner 10b of the tire roller 10.

The detection range calculation means 32 is means for calculating the detection ranges 4A and 4B for detecting the presence or absence of obstacles based on the projection range N1 and the estimated travel route 21, respectively. The detection range calculator 32 calculates the portions where the projection range N1 and the estimated travel route 21 overlap as detection ranges 4A and 4B for detecting the presence or absence of obstacles. As shown in FIG. 7, the detection range 4A (hatched portion in FIG. 7) when the tire roller 10 turns has a generally arc shape. The rear end of the detection range 4A is set to a third virtual line 21d perpendicular to the tangent line of the second virtual line 21c at the intersection Q between the second virtual line 21c and the projection range N1. The position of the third imaginary line 21d may be appropriately set in the portion where the projection range N1 and the estimated travel route 21 overlap, depending on the travel speed commonly used.

As shown in FIG. 8, even when the tire roller 10 travels straight, the detection range calculation means 32 calculates the portion where the projected range N1 and the estimated travel route 21 overlap as the detection range 4B (hatched portion in FIG. 8) for detecting the presence or absence of an obstacle. The detection range 4B has a substantially rectangular shape. The rear end of the detection range 4B may be appropriately set in the portion where the projection range N1 and the estimated travel route 21 overlap, according to the commonly used travel speed.

According to the obstacle detection device 1A described above, in addition to the effects of the obstacle detection device 1 of the first embodiment, the following effects can be obtained.
(1) Since the detection ranges 4A and 4B are set according to the estimated travel route 21 calculated from the turning radius of the tire roller (construction vehicle) 10, the desired detection ranges can be set depending on whether the vehicle is going straight or turning. That is, the detection ranges 4A and 4B can be set according to the width of the vehicle both when the tire roller 10 moves straight and when it turns, so that the travel route of the vehicle and the detection range can be matched just enough. As a result, it is possible to prevent useless warnings and vehicle stoppages both when the tire roller 10 is traveling straight and when turning, and to reliably detect obstacles included in the estimated travel route 21 when turning.

The width dimension of the estimated travel route 21 may be set to be wider than the vehicle width dimension by several centimeters or several tens of centimeters. Alternatively, the angle sensor 8 may be omitted and a sensor or mechanism capable of obtaining the rotation radius of the tire roller 10 may be used. The present invention can also be applied to construction vehicles other than compaction machines, and can also be applied to articulated construction vehicles.

[Third Embodiment]
Next, a construction vehicle obstacle detection device according to a third embodiment of the present invention will be described. FIG. 9 is a plan view showing an estimated travel route when turning in the obstacle detection device according to the third embodiment. FIG. 10 is a plan view showing the detection range when turning in the obstacle detection device according to the third embodiment.

As shown in FIG. 9, an obstacle detection device 1B according to the third embodiment is mainly composed of a distance image sensor 2, a control device 3, braking means 6, a vehicle speed sensor 7, and an angle sensor 8. The obstacle detection device 1B according to the third embodiment differs from the second embodiment in the estimated travel route calculation means 31 and the detection range calculation means 32 of the control device 3 . In the third embodiment, the description will focus on the parts that are different from the second embodiment.

In the present embodiment, the estimated running path 21A of the tire roller 10 shown in FIG. 9 means the trajectory that the first corner portion 10a and the front outermost portion 10c pass after t seconds when the tire roller 10 moves forward or backward. The first corner portion 10a is the innermost part of the vehicle that travels when turning. The front-side outermost portion 10c is a portion that runs on the outermost side of the vehicle when turning. The time t may be set as appropriate, and is set between 3 and 10 seconds, for example. That is, the estimated travel route 21A is an area surrounded by the first virtual line 21b and the fourth virtual line 21e.

As in the second embodiment, the first imaginary line 21b is the turning radius R1 of the locus of the first corner portion 10a, which is calculated based on the turning angle (for example, turning angle α) of the front tire 11, the wheelbase, and the like. The fourth imaginary line 21e is the turning radius R3 of the trajectory of the front outermost portion 10c, which is calculated based on the steering angle (for example, steering angle α) of the front tire 11, the wheelbase, and the like. That is, the fourth imaginary line 21e is the turning radius (outermost diameter) of the outermost portion of the vehicle.

When the tire roller 10 travels straight, as in the second embodiment (see FIG. 8), the turning angle of the front tire 11 is 0°, so the estimated travel route calculation means 31 calculates the estimated travel route 21A so that the first virtual line 21b and the second virtual line 21c are parallel along the vehicle width from the first corner 10a and the second corner 10b of the tire roller 10. That is, in the third embodiment, when turning, the estimated travel route 21A is calculated based on the first corner 10a and the front outermost portion 10c, and when going straight, the estimated travel route 21A is calculated based on the first corner 10a and the second corner 10b.

The detection range calculation means 32 is means for calculating detection ranges 4B and 4C for detecting the presence or absence of obstacles based on the projection range N1 and the estimated travel route 21A. The detection range calculation means 32 calculates the portions where the projection range N1 and the estimated travel route 21A overlap as detection ranges 4B and 4C for detecting the presence or absence of obstacles. As shown in FIG. 10, the detection range 4C (hatched area in FIG. 10) when the tire roller 10 turns is a range in which the outer diameter side is expanded outward compared to the second embodiment (see FIG. 7). The rear end of the detection range 4C is set to a fifth virtual line 21g perpendicular to the tangent line of the fourth virtual line 21e at the intersection QA between the fourth virtual line 21e and the projection range N1. The position of the fifth imaginary line 21g may be appropriately set in the portion where the projection range N1 and the estimated travel route 21A overlap, depending on the travel speed that is commonly used.

When the tire roller 10 travels straight, similarly to the second embodiment (see FIG. 8), the detection range calculation means 32 calculates the portion where the projection range N1 and the estimated travel route 21A overlap as the detection range 4B (hatched portion in FIG. 8) for detecting the presence or absence of an obstacle. The detection range 4B has a substantially rectangular shape. The rear end of the detection range 4B may be appropriately set in the portion where the projection range N1 and the estimated travel route 21 overlap, according to the commonly used travel speed.

As shown in FIG. 10, when the vehicle turns, the front outermost portion 10c travels further outside than the second corner portion 10b, but the worker working behind the vehicle tends to concentrate on the rear end portion 21a of the vehicle and tend to neglect the front outermost portion 10c. In this regard, according to the obstacle detection device 1B according to the third embodiment, since the outer side of the detection range 4C is set to extend outside the vehicle width, the obstacle G in the range outside the second virtual line 21c and inside the fourth virtual line 21e (hereinafter, this range is also referred to as the "outermost diameter range") can be reliably detected.

When the steering wheel is turned largely (when the steering angle of the front tire 11 is large), the width dimension of the outermost diameter range becomes larger. However, if this setting is made according to all the steering angles, there is a risk that an unnecessary alarm will be sounded or a sudden stop will be unnecessary when rolling near the wall W, for example, due to the widening of the outer detection range.

Therefore, when the vehicle is traveling straight and when the steering angle (steering angle of the front tire 11) is smaller than a predetermined threshold value, the estimated travel routes 21 and 21A may be calculated based on the first virtual line 21b and the second virtual line 21c as in the second embodiment. This makes it possible to further prevent unnecessary alarms and unnecessary sudden stops.

Also, different estimated travel routes 21 and 21A may be set depending on whether the vehicle is moving forward or backward. For example, when the vehicle turns while moving forward, the estimated travel route 21 may be calculated based on the first virtual line 21b and the second virtual line 21c as in the second embodiment, and when the vehicle makes a turn while moving backward, the estimated travel route 21A may be calculated based on the first virtual line 21b and the fourth virtual line 21e as in the third embodiment, and the respective detection ranges may be set. Conversely, when the vehicle turns while moving forward, the estimated travel route 21A may be calculated based on the first virtual line 21b and the fourth virtual line 21e as in the third embodiment, and when the vehicle makes a turn while moving backward, the estimated travel route 21 may be calculated based on the first virtual line 21b and the second virtual line 21c as in the second embodiment, and the respective detection ranges may be set.

Also, just to be sure, in the second embodiment and the third embodiment, as in the first embodiment, when the control device 3 determines that there is an obstacle, braking means (for example, an HST brake, a parking brake device, a drum brake device, etc.) that brakes the vehicle may be provided. Also in the second embodiment and the third embodiment, as in the first embodiment, the braking start timing may be changed according to the limit braking distance T of the vehicle, which changes depending on the running speed.

In the second and third embodiments, the TOF (Time Of Flight) type distance image sensor (3D distance sensor) 2 capable of measuring the distance to an object using projection and reflection is illustrated as an object detection sensor, but the present invention is not limited to this. The object detection sensor may be, for example, an ultrasonic sensor, microwave sensor, laser light sensor, infrared sensor, radar system, lidar system, stereo camera system, monocular camera system, or the like that can detect an object within a predetermined range.

1 obstacle detection device 1A obstacle detection device 2 distance image sensor (object detection sensor)
3 control device 4 detection range 4A detection range 4B detection range 5 non-detection range 6 braking means 7 vehicle speed sensor 8 angle sensor 10 tire roller (construction vehicle)
21 Estimated travel route 21A Estimated travel route

Claims (4)

An obstacle detection device mounted on a construction vehicle,
an object detection sensor that detects an obstacle within a predetermined range;
a control device that calculates an estimated travel route of the construction vehicle based on the turning radius of the construction vehicle and determines the presence or absence of an obstacle based on the detection result of the object detection sensor;
The control device sets a range in which the projection range of the object detection sensor and the estimated travel route overlap as a detection range for detecting the presence or absence of the obstacle, and a non-overlapping range as a non-detection range,
The detection range is
When traveling straight, the width is set to be approximately the same as the width of the construction vehicle,
An obstacle detection device for a construction vehicle, wherein an outer side of the detection range is set wider than a width of the vehicle so as to correspond to an outermost diameter of the construction vehicle when turning. 2. The obstacle detection device for a construction vehicle according to claim 1 , further comprising braking means for applying a brake to the vehicle when said control device determines that there is an obstacle. The construction vehicle is a compaction roller,
3. The obstacle detection device for a construction vehicle according to claim 2 , wherein said braking means is an HST brake acting on a closed circuit of a running pump and a running motor. 4. The obstacle detection device for a construction vehicle according to claim 2, wherein the braking start timing of said braking means changes according to the running speed of the vehicle.

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