Construction vehicles

Abstract

To provide construction vehicles that can be categorized into levels according to the degree of danger of the object being worked on, thereby achieving a balance between safety and work efficiency. [Solution] A construction vehicle having a braking means for braking the wheels, comprising an object sensor for detecting an object, and a control unit that activates the braking means under predetermined conditions when a detection signal is output from the object sensor, wherein the control unit has multiple levels (levels P1 to P3) set according to the degree of danger of the object detected by the object sensor, and changes the length of the detection area of ​​the object sensor and / or the width perpendicular to the length in accordance with each level.

Description

Technical Field

[0001] The present invention relates to a construction vehicle such as a compaction roller, for example.

Background Art

[0002] In a compaction roller, for example, when compressing while getting as close as possible to a curb, the driver drives while watching the compaction surface around the curb, so it is easy to neglect attention in the traveling direction. Therefore, particularly when the vehicle is reversing, an accident of contacting surrounding workers easily occurs.

[0003] Regarding this problem, an alarm device that uses radio waves or ultrasonic waves and issues an alarm when detecting a person or an object at a certain distance, or an automatic stop device that automatically stops the vehicle is known (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses an emergency stop device including a magnetic field generation device mounted on a vehicle, an IC tag worn by an operator, a detection device that detects radio waves transmitted from the IC tag, and an engine stop device that stops the vehicle when the detection device detects radio waves. Patent Document 2 discloses a stop system including a trigger signal output means mounted on a vehicle, an ID tag worn by an operator, a receiving unit that receives the ID number output by the ID tag, and a stop means that stops the vehicle when the receiving unit receives the ID number.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, conventional emergency braking systems did not distinguish between "people" and "objects" as the objects to be detected (see Figure 5(a)). As a result, even though the degree of danger differs depending on the object, there was no difference in the operation of the emergency braking system or the warning issued between "people" and "objects," and the system activated uniformly when an object was detected. For example, "objects" such as walls and road cones (pylons) pose a lower risk than "people," but if the emergency brake is activated every time an "object" is detected, it reduces work efficiency.

[0006] Furthermore, road surface compaction is carried out by running multiple compaction rollers in parallel in the longitudinal or transverse direction (also known as the Echelon method). In the conventional Echelon method, despite the fact that the degree of danger differs depending on the speed and direction of other vehicles, there was no difference in the activation of the emergency braking system or the warning issued, and it activated uniformly when other vehicles were detected. For example, when another vehicle is traveling in the same direction and at the same speed as the vehicle, the degree of danger is lower than when another vehicle is approaching the vehicle at high speed, but there is a problem that work efficiency decreases if the emergency brake is activated every time another vehicle is detected.

[0007] This invention was created to solve these problems, and aims to provide a construction vehicle that achieves both safety and workability by classifying the target object into levels according to its degree of danger. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides a construction vehicle having a braking means for braking the wheels, comprising: an object sensor for detecting an object; and a control unit that activates the braking means under predetermined conditions when a detection signal is output from the object sensor, wherein the control unit has a plurality of levels set according to the degree of danger of the object detected by the object sensor, and changes the length of the detection area of ​​the object sensor and / or the width perpendicular to the length in accordance with each of the levels.

[0009] According to the present invention, by classifying objects into levels according to their degree of danger and changing the detection area according to these levels, it is possible to improve work efficiency while ensuring safety.

[0010] Furthermore, in the present invention, it is preferable that the degree of risk is classified into levels according to the type of object.

[0011] According to the present invention, safety and work efficiency can be achieved by classifying objects into levels based on their type, such as "people," "other vehicles," and "objects." Further subdivision of these categories is also possible.

[0012] Furthermore, in the present invention, it is preferable that each level is set to a low level with a low degree of risk for stationary objects other than people, a medium level with a moderate degree of risk for moving objects other than people, and a high level with a high degree of risk for people.

[0013] Furthermore, in the present invention, it is preferable that the control unit performs brake control by the braking means when the level is low, performs warning control followed by brake control by the braking means when the level is medium, performs caution control followed by warning control when the level is high, and further performs brake control by the braking means after the warning control.

[0014] Furthermore, in the present invention, it is preferable that the control unit performs a warning control in the case of a low level and then performs brake control by the brake means in the case of a medium level.

[0015] Furthermore, in the present invention, it is preferable that the detection area of ​​the object sensor is narrower at the tip end than at the base end end.

[0016] According to the present invention, for example, when a vehicle turns, low-risk objects are no longer detected on both sides in the width direction at the leading edge of the detection area, thereby improving work efficiency.

[0017] In the present invention, it is preferable that the degree of risk is classified into levels according to the relative speed between the host vehicle and the object.

[0018] According to the present invention, for example, by classifying according to the relative speed with an object (for example, another vehicle), it is possible to achieve both safety and workability.

[0019] Furthermore, in the present invention, when the relative speed between the host vehicle and the object is set such that the side moving away from each other is positive and the side approaching each other is negative, when the relative speed is negative, it is preferable that the length of the detection area of the object sensor and / or the width orthogonal to the length is set larger than when the relative speed is zero or positive.

[0020] Furthermore, in the present invention, when the relative speed between the host vehicle and the object is set such that the side moving away from each other is positive and the side approaching each other is negative, when the relative speed is negative, it is preferable that the length of the detection area of the object sensor and / or the width orthogonal to the length is set larger as the absolute value of the relative speed is larger.

[0021] Furthermore, in the present invention, when the relative speed between the host vehicle and the object is set such that the side moving away from each other is positive and the side approaching each other is negative, when the relative speed is positive, it is preferable that neither caution control nor warning control nor brake control is performed.

[0022] Furthermore, in the present invention, the object is preferably a moving object other than a person.

[0023] Furthermore, in the present invention, the relative speed is preferably acquired based on a detection signal from a relative speed detection sensor installed in the host vehicle or another vehicle.

[0024] Furthermore, in the present invention, the relative speed is preferably obtained by calculating the own speed of the host vehicle and the other speed of the other vehicle.

[0025] Furthermore, in the present invention, the relative speed is preferably acquired by information provided by a third party.

[0026] Furthermore, in the present invention, each of the above levels is preferably set to a low level with a low degree of danger, a medium level with a medium degree of danger, and a high level with a high degree of danger according to the relative speed.

[0027] Furthermore, in the present invention, the control unit performs brake control by the brake means in the case of the low level, performs brake control by the brake means after performing warning control in the case of the medium level, performs caution control and then warning control in the case of the high level, and furthermore, preferably performs brake control by the brake means after the warning control.

[0028] Furthermore, in the present invention, the control unit preferably performs brake control by the brake means after performing warning control in the case of the low level, and performs brake control by the brake means in the case of the medium level.

[0029] Furthermore, in the present invention, it is preferable that the detection area of the object sensor has a narrower width on the tip side than on the base end side.

Advantages of the Invention

[0030] According to the present invention, it is possible to obtain a construction vehicle that classifies levels according to the degree of danger of an object and achieves both safety and workability.

Brief Description of the Drawings

[0031] [Figure 1] It is an explanatory diagram showing the detection area of an obstacle detection device mounted on a tire roller, and (a) and (b) are a plan view and a side view, respectively. [Figure 2] It is a configuration block diagram of an obstacle detection device according to the present invention. [Figure 3] It is a schematic hydraulic circuit diagram of a traveling system including brake means. [Figure 4]This graph shows the braking start distance. [Figure 5] (a) is a schematic plan view showing each area when the emergency brake is activated in the prior art, (b) is a schematic plan view showing each area at level P1 of the present invention, (c) is a schematic plan view showing each area at level P2 of the present invention, and (d) is a schematic plan view showing each area at level P3 of the present invention. [Figure 6] This is a flowchart for determining each level according to the type of object. [Figure 7] This characteristic diagram shows the relationship between the vehicle's speed and the distance to the object, and the emergency brake activation area, warning area, and attention area. [Figure 8] This is a side view showing the state in which warnings are being issued by speakers SP1 and SP2 installed in the vehicle. [Figure 9] This is a schematic plan view showing the state in which the width dimension of the detection area of ​​the distance image sensor has been expanded from width dimension L1 to width dimension L4. [Figure 10] This is a schematic plan view showing a reduced width dimension of the detection area of ​​the distance image sensor. [Figure 11] This is a schematic plan view showing a reduced width dimension of the detection area of ​​the distance image sensor. [Figure 12A] This is a schematic plan view showing the state in which the width dimension of the detection area of ​​the distance image sensor is reduced when the vehicle is turning. [Figure 12B] This is a schematic plan view showing the expanded width of the detection area of ​​the distance image sensor when the vehicle is turning. [Figure 13] (a) to (d) are schematic plan views showing the levels of the situation according to the relative speed between your vehicle and the other vehicle. [Figure 14] This is a flowchart for determining each level based on the relative speed between your vehicle and the other vehicle. [Figure 15] This is an explanatory diagram for calculating the relative speed between your vehicle and the other vehicle. [Figure 16]This is an explanatory diagram showing the specific calculation methods for Level R2 and Level R3, which correspond to the relative speed between your vehicle and the other vehicle. [Figure 17] (a) is a characteristic diagram showing the relationship between time and speed in both your vehicle and the other vehicle from the moment your vehicle's emergency brakes are applied, and (b) is a characteristic diagram showing the relationship between time and cumulative distance in both your vehicle and the other vehicle from the moment your vehicle's emergency brakes are applied. [Modes for carrying out the invention]

[0032] In Figure 1, the obstacle detection device according to a reference embodiment of the present invention is mounted on a construction vehicle with a compaction roller that performs compaction work while traveling at a low speed. Figure 1 shows the obstacle detection device 1 mounted on a tire roller 10 that compacts asphalt road surfaces with tires. In Figure 2, the obstacle detection device 1 is configured to include a TOF (Time Of Flight) type distance image sensor (3D distance sensor) 2 that measures distance from the time difference between projected light and reflected light, and a control unit 3 that determines the presence or absence of an obstacle G based on the measurement data of the distance image sensor 2.

[0033] The distance image sensor 2 comprises a light-emitting unit that emits projected light such as infrared light, and a light-receiving unit that receives reflected light when the projected light strikes an object. The distance to the object is measured by measuring the time from when the infrared light is sent from the light-emitting unit until the reflected light is received by the light-receiving unit. 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 Figure 1(b)), and the projection cross-section is a horizontally elongated rectangle. 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 mounted on the rear of the tire roller 10 in the center in the vehicle width direction, so that the projected light is projected diagonally downward in the direction of vehicle reversing. The distance image sensor 2 functions as an object sensor that detects objects, as will be described later.

[0034] Regarding the detection area for obstacle G, if the projection range of the projected light is set directly as the detection area, that is, if the width dimension L1 in the vehicle width direction is set wider than the vehicle width dimension of the tire roller 10, the vehicle may stop unnecessarily because it is recognized that there is an obstacle G even though there is no risk of collision. For this reason, it is preferable that the width dimension L1 of the detection area in the vehicle width direction (the area shown by the lanes in Figure 1) be set to be approximately the same as the vehicle width dimension of the tire roller 10. Since the distance image sensor 2 can measure the distance to the obstacle, the control unit 3 can determine whether or not an obstacle G exists in the detection area 4 set to the vehicle width dimension from the measurement data for each pixel, specifically the distance in the vehicle width direction between the distance image sensor 2 and the obstacle G. By using the distance image sensor 2 in this way, the width dimension L1 of the detection area 4 can be kept constant over the vehicle's front-to-rear direction. In other words, the detection area 4 can be easily set to a roughly rectangular area with one side having a width dimension L1 in a plan view, as shown in Figure 1(a). The length L2 of the detection area 4 in the vehicle's longitudinal direction is set appropriately according to the commonly used driving speed, and in this embodiment, it is set to approximately 3 to 8 meters.

[0035] Furthermore, since the light projected by the distance image sensor 2 is projected diagonally downward in the reverse direction, the lateral angle θ2 of the projected light when viewed from above is even larger than 95°. Therefore, the distance L3 in the vehicle's longitudinal direction for 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. In other words, the blind spots of non-detection formed on both sides of the rear of the vehicle can be reduced.

[0036] The control unit 3 is equipped with a braking means 6 that applies the brakes to the vehicle when it determines that there is an obstacle G in the detection area 4 (see Figure 2). An example of the braking means 6 is described below. In Figure 3, a drive pump Q driven by an engine (not shown) and a drive motor M that rotates the tires 11 (Figure 1) are connected in series to form a hydraulic closed circuit U1. The drive pump Q is a swashplate pump. Oil passages T1 and T2 for operating the swashplate are connected to the drive pump Q. A two-position, three-port electromagnetic valve V1 is interposed between oil passages T1 and T2 in parallel with the drive pump Q.

[0037] When the engine is running, the electromagnetic valve V1 is in the right position in Figure 3, and does not connect oil passages T1 and T2. Therefore, when the engine is running, tilting the forward / reverse lever around the driver's seat to the forward position causes the swash plate hydraulic fluid to flow from oil passage T1 to oil passage T2, tilting the swash plate to one side. As a result, the pressurized oil flows in one direction within the closed circuit U1, causing the drive motor M to rotate in one direction and the vehicle to move forward. When the forward / reverse lever is tilted to the reverse position, the swash plate hydraulic fluid flows from oil passage T2 to oil passage T1, tilting the swash plate to the other side. As a result, the pressurized oil flows in the other direction within the closed circuit UI, causing the drive motor M to rotate in the other direction and the vehicle to move backward.

[0038] When the engine is not running, the solenoid valve V1 is in the left position as shown in Figure 3, and oil passages T1 and T2 are in communication. A closed hydraulic circuit U2 is formed between the solenoid valve V1 and the drive pump Q, and since there is no differential pressure between oil passages T1 and T2, the swashplate is in the neutral position. As a result, the HST (Hydro Static Transmission) brake is activated in the closed circuit U1.

[0039] The braking means 6 of this embodiment utilizes the electromagnetic valve V1. When an obstacle is detected while reversing, the control unit 3 outputs a brake signal and switches the electromagnetic valve V1 from the right position to the left position. As a result, even with the engine running and the forward / reverse lever tilted to the reverse position, the swashplate is positioned in the neutral position, the HST brake is activated in the closed circuit U1, and the drive motor M stops. An electromagnetic valve V2 is interposed between the charge pump Q1 built into the drive pump Q and the negative brake M1 built into the drive motor M to activate the negative brake M1 when parked.

[0040] It is preferable that the timing from when the control unit 3 determines the presence of an obstacle G until it outputs a brake signal, that is, the timing at which the brake means 6 starts braking, be changed according to the vehicle's speed. As shown in Figure 4, the control unit 3 compares a preset brake start distance S according to the speed with the distance to the obstacle G in the detection area 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 less than or equal to the brake start distance S.

[0041] The braking initiation distance S is set to a distance that provides a slight margin over the actual limit braking distance T of the vehicle. In Figure 4, the braking initiation distance S is set to approximately 0.5 m at 2 km / h, approximately 1 m at 4 km / h, approximately 1.6 m at 6 km / h, and approximately 2.4 m at 8 km / h. The vehicle speed sensor 7 (Figure 2) that detects the vehicle's speed can be a proximity sensor such as a rotary encoder that detects the rotation speed of the tires.

[0042] As described above, the obstacle detection device 1 for construction vehicles, which includes a TOF (Time of Flight) type distance image sensor 2 that measures distance from the time difference between projected light and reflected light, and a control unit 3 that determines the presence or absence of an obstacle G based on the measurement data from the distance image sensor 2, provides the following effects. (1) The TOF distance image sensor 2 can accurately measure the distance to the target, and therefore has excellent obstacle detection accuracy. (2) Unlike detection methods using radio waves, there is no need to attach detection tags to nearby workers, thus reducing costs. Furthermore, there is no problem of forgetting to attach detection tags, and obstacles can be reliably detected. (3) By using the distance image sensor 2, the detection area 4 can be easily set to a desired size, such as setting the detection area 4 to the width of the vehicle.

[0043] If the distance image sensor 2 is installed so that the projected light is directed diagonally downward in the direction of travel of the vehicle, and the control unit 3 is configured to determine the presence or absence of obstacles in a detection area 4 that is roughly rectangular in plan view and has a width dimension L1 that is roughly the same as the width of the vehicle, then the following effects can be achieved. (1) By creating a detection area 4 that is roughly rectangular in plan view and has a width dimension L1 that is roughly the same as the width of the vehicle, the system can recognize the presence of an obstacle G only when there is a high risk of collision with the vehicle, and take measures such as stopping the vehicle or sounding an alarm. This avoids unnecessary vehicle stops and alarms.

[0044] (2) By projecting the light diagonally downward in the direction of travel of the vehicle, the lateral angle θ2 of the projected light when viewed from above can be increased. This makes it possible to reduce the distance L3 of the undetected range 5 and reduce the undetected blind spots formed on both sides of the rear of the vehicle.

[0045] If the control unit 3 determines that there is an obstacle G, and the system is equipped with a braking means 6 that applies the brakes to the vehicle, collisions with 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 inconvenience of restarting the engine when resuming work.

[0046] In particular, in a compaction roller such as a tire roller 10, if the braking means 6 is an HST brake that acts on the closed circuit U1 of the travel pump Q and the travel motor M, excessive sudden stops can be avoided compared to when the engine is stopped, etc., thereby reducing flatness defects such as depressions in the asphalt pavement surface. Furthermore, restarting the operation becomes easier.

[0047] If the braking start timing of the braking means 6 is configured to change according to the vehicle's speed, the following effects can be achieved. If the brakes are applied to the vehicle even when a worker temporarily enters the detection area 4 and then immediately leaves the detection area 4, the vehicle's work efficiency will decrease. In contrast, by changing the braking start timing according to the vehicle's limit braking distance T, which changes with the speed, the brakes can be applied to the vehicle only when there is a high risk of collision according to the speed, thereby reducing unnecessary vehicle stops.

[0048] Preferred reference embodiments of the present invention have been described above. In the reference embodiments, a braking means 6 is provided to apply the brakes to the vehicle when an obstacle G is detected, but in some cases, a warning may be issued by sound or light instead of the braking means 6. Alternatively, the braking means 6 and the warning may be used in combination. Furthermore, a distance image sensor 2 may be attached to the front of the vehicle to detect the direction of the vehicle's forward movement.

[0049] [First Embodiment] Next, a construction vehicle according to the first embodiment of the present invention will be described. Note that components identical to those in the above-mentioned reference embodiment are given the same reference numerals, and their detailed descriptions are omitted.

[0050] The obstacle detection device 1 according to this embodiment comprises a Time of Flight (TOF) type distance image sensor (3D distance sensor) 2 that measures distance from the time difference between projected light and reflected light, and a control unit 3 that determines the presence or absence of an obstacle G based on the measurement data and imaging data of the distance image sensor 2. The distance image sensor 2 constitutes the "object sensor".

[0051] In this embodiment, multiple levels are set according to the degree of danger of the object detected by the distance image sensor 2, and the length of the detection area 4 of the distance image sensor 2, and / or the width perpendicular to the length are changed according to each level. In this embodiment, the degree of danger is divided into levels according to the type of object detected by the distance image sensor 2.

[0052] The distance image sensor 2 of this embodiment uses 3D-TOF for image processing in addition to distance measurement. The projection range of the distance image sensor 2 of this embodiment is wider than the width of the vehicle and is set to an area within approximately 10m from the rear of the tire roller 10.

[0053] Distance data to the object measured by the distance image sensor 2 and image data of the object are transmitted to the control unit 3. The control unit 3 is equipped with a type determination unit that determines the type of the imaged object. By performing machine learning, the type determination unit can determine whether the imaged object is, for example, a "person," a "moving object other than a person," or a "stationary object." The control unit 3 also stores the type of the imaged object and the distance data in a memory unit in association with each other.

[0054] Figure 5(a) shows the conventional technology. In the conventional technology, detection targets did not distinguish between "people" and "objects (other vehicles, walls, etc.)". Therefore, in the conventional technology, there was no difference in the activation of emergency brakes or warnings between "people" and "objects (other vehicles, walls, etc.)", and the system was activated uniformly when an object was detected. This uniform activation of emergency brakes and warnings regardless of the type of object resulted in decreased work efficiency and increased burden on the operator.

[0055] In road compaction work, many workers are working around the compaction rollers. For example, there are road surface temperature measurers, quality monitors, plate / rammer / hand guide operators, rake operators, security guards, and many other types of workers. In addition, multiple compaction rollers are used for primary compaction, secondary compaction, and finish compaction, and they compact the road by repeatedly going back and forth on the same lane.

[0056] Furthermore, compaction rollers may move towards or away from each other while facing each other, move in the same direction, or move in a transverse direction at joints. In addition, in maintenance and repair work on existing structures, traffic is often stopped on only one side of the road to carry out the work, and the area is often demarcated with road cones. In such cases, the area immediately outside the road cones is made into a temporary sidewalk, where general pedestrians and cyclists use the road, and security guards often work with their backs to the paved surface.

[0057] Furthermore, the operator of a compaction roller has many tasks to perform, including ensuring the safety of the direction of travel, preventing asphalt mixture from sticking to the roll tires, and checking the quality of the compacted surface. Moreover, the compaction work must be completed before the temperature of the asphalt mixture drops, requiring operators to maintain a high level of attention and quick response at all times.

[0058] In situations like this, if only "people" such as workers are detected, "objects" (other vehicles, walls, etc.) will not be detected. Eliminating reactions from "objects" improves work efficiency and, at first glance, appears to improve safety. However, at paving construction sites, plates, rammers, hand-guided rollers, etc., are sometimes temporarily placed and installed very close to walls and guardrails. Operators may become so focused on the quality of the paving surface that they fail to notice an obstacle and make contact. In that case, they may not know what they touched, or they may not even realize they touched anything, only becoming suspicious due to an unusual noise. Alternatively, they may take evasive action in a state of mild panic in response to emergency stop signals from people around them, potentially causing secondary damage. Therefore, it is important to make operators aware of obstacles in their path using an emergency braking system. Furthermore, by reacting not only to workers but also to "objects" and issuing alarms, it is possible to immediately connect this to hazard prediction activities throughout the entire site by identifying locations and arrangements that could lead to danger. Furthermore, in the event of a potential collision, the emergency brakes will activate, contributing to improved safety.

[0059] In light of these challenges, in this embodiment, objects detected by the distance image sensor 2 (object sensor) are classified into levels, and the size of the detection area 4 is changed according to each level, such as a caution area, an alarm area, and an emergency braking area (see Figures 5(b) to (d)). In the following example, a smaller number indicates a higher level and higher priority (higher danger) than a larger number.

[0060] (Example of level classification 1) The level classification can be set appropriately according to the type of object detected. In this example, Level 1 (Level P1) is defined as "people". Level 2 (Level P2) is defined as moving objects other than people (for example, other vehicles excluding your own car). Level 3 (Level P3) is defined as stationary objects (for example, structures such as walls and guardrails, road cones). In this example of level classification 1, each level is composed of Level 1, Level 2, and Level 3 (see Figures 5(b) to (d)). Level 1 (Level P1) functions as a "high level" with a high degree of risk, targeting people. Level 2 (Level P2) functions as a "medium level" with a moderate degree of risk, targeting moving objects other than people. Level 3 (Level P3) functions as a "low level" with a low degree of risk, targeting stationary objects other than people.

[0061] For example, as shown in Figure 5(b), when the distance image sensor 2 determines that an object detected within its projection range is a "person," the length of the detection area 4 for activating the emergency brake is set to 1.9m from the rear of the vehicle, the length of the detection area 4 for activating the alarm is set to 3.5m from the rear of the vehicle, and the length of the detection area 4 for issuing a warning is set to 7.4m from the rear of the vehicle. The width of the detection area 4 is set to be the same as the width of the vehicle. In other words, since contact with a person must be avoided at all costs, the warning area is set to be wider, and a warning is issued when a person enters the warning area. In the example in Figure 5(b), a person is inside the warning area, so the control unit 3 performs the warning process.

[0062] For example, as shown in Figure 5(c), if the object detected within the projection range by the distance image sensor 2 is determined to be "another vehicle (a moving object other than a person)", the length of the detection area 4 for activating the emergency brake is set to 1.9m from the rear of the vehicle, and the length of the detection area 4 for activating the alarm is set to 3.5m from the rear of the vehicle. No warning area is set for issuing a warning. This is because other vehicles (moving objects other than people) pose less danger than people, so a warning area is not provided to reduce the burden on the operator (a warning is issued even though the danger is low). In the example in Figure 5(c), since no other vehicle is inside the alarm area, the control unit 3 does not perform any alarm processing in this state.

[0063] Furthermore, as shown in Figure 5(d), for example, if the object detected within the projection range by the distance image sensor 2 is determined to be a "wall (stationary object)", the length of the detection area 4 for activating the emergency brake is set to 1.3m from the rear of the vehicle, and the length of the detection area 4 for issuing a warning is set to 3.0m from the rear of the vehicle. No warning area is set for activating an alarm. This is because walls (stationary objects) pose less danger than other vehicles (moving objects other than people), so an alarm area is not provided to reduce the burden on the operator (an alarm being issued despite the low level of danger). Also, because the level of danger is low, safety can be ensured by activating the emergency brake after issuing a warning without issuing an alarm. In addition, because the level of danger is low, the distance of the warning area is also set to be short. Note that in the example in Figure 5(d), there is no wall within the warning area, so in this state the control unit 3 does not issue a warning or anything like that.

[0064] (Example of level classification 2) Although specific illustrations are omitted, in Example 2 of the level classification, the first level is defined as moving objects approaching the vehicle (people + moving objects), the second level as moving objects crossing the vehicle (other vehicles, etc.), the third level as stationary objects (e.g., walls, guardrails and other structures, road cones), and the fourth level as moving objects moving away from the vehicle (other vehicles). In this Example 2 of the level classification, the levels are divided into four stages, from the first to the fourth level.

[0065] (Example of level classification 3) Although specific illustrations are omitted, in Example 3 of the level classification, Level 1 is defined as "people," Level 2 as moving objects other than people approaching the vehicle (other vehicles), Level 3 as moving objects other than people crossing the vehicle (other vehicles), Level 4 as stationary objects (e.g., walls, guardrails and other structures, road cones), and Level 5 as moving objects other than people moving away from the vehicle (other vehicles). In this Example 3 of the level classification, levels 1 through 5 are used to divide the vehicle into five stages.

[0066] (Example of level classification 4) Although specific illustrations are omitted here, in example 4 of the level classification, Level 1 is defined as "general pedestrians," Level 2 as "persons indirectly involved in construction, such as security guards," and Level 3 as "construction personnel familiar with the work." In this example of level classification, there are three levels: Levels 1 through 3.

[0067] (Example of level classification 5) Although specific illustrations are omitted, in example 5 of the level classification, Level 1 is defined as "people facing backward, crouching, or lying down," Level 2 as "people standing with more than half of their body facing forward," and Level 3 as "people standing, looking forward, and recognizing the vehicle." In this example of level classification, there are three levels: Levels 1 to 3.

[0068] Thus, the level classifications for each type of object can be set as appropriate, based on factors such as how the object is categorized, whether it is stationary or moving, and in which direction it is moving.

[0069] More specifically, as phenomena unique to road construction, the risk levels within the construction area can be categorized as follows, from least to most dangerous: 1. Existing structures such as walls, signs, and buildings as stationary objects. When working with existing structures, it may be necessary to work in close proximity, or to work in other areas while working in close proximity. Furthermore, there may be cases where work is performed on existing structures themselves, or where work is performed while maintaining contact with existing structures. 2. Signs, road cones, or other objects that clearly demarcate areas, or stationary machinery operating simultaneously. The reason for approaching objects that demarcate sections is the same as in point 1 above. Additionally, some construction projects require coordination with stationary machinery. 3. Mobile machinery operating simultaneously Because the work is confined to a limited area, vehicles frequently pass each other. Additionally, some construction projects require coordination with mobile machinery. 4. Workers Even with safety training, predicting their actions is difficult. While accidents involving personal injury will result in a halt to construction, accidents involving property damage may not necessarily require a halt.

[0070] Furthermore, as a phenomenon specific to road construction, the areas outside the construction zone can be classified as follows, in order of increasing risk: 1. General vehicles passing outside the area as objects. The risk of contact is low. 2. Guard Although safety training is provided, the duties of monitoring and directing traffic both inside and outside the designated area can sometimes lead to distractions. 3. Ordinary people Its actions are difficult to predict. Furthermore, accidents involving civilians must be avoided.

[0071] Next, the flowchart for level determination will be explained below based on Example 1 of level classification (see Figure 6).

[0072] First, the control unit 3 determines whether or not an object has been detected by the distance image sensor 2 (step S1). In step S1, if the control unit 3 determines that an object has been detected by the distance image sensor 2 (step S1 → Yes), it proceeds to step S2. Conversely, in step S1, if the control unit 3 determines that an object has not been detected by the distance image sensor 2 (step S1 → No), it proceeds to return and returns to start.

[0073] In step S2, the control unit 3 determines whether the object detected by the distance image sensor 2 is a "person". If the control unit 3 determines that the object detected by the distance image sensor 2 is a "person" (step S2 → Yes), it proceeds to step S3 and determines that the danger level is level P1. Then, the control unit 3 proceeds to step S4 and performs the processing corresponding to level P1.

[0074] In step S2, if the control unit 3 determines that the object detected by the distance image sensor 2 is not a "person" (step S2 → No), it proceeds to step S5. In step S5, the control unit 3 determines whether or not the object detected by the distance image sensor 2 is a "moving object".

[0075] In step S5, if the control unit 3 determines that the object detected by the distance image sensor 2 is a "moving object" (step S5 → Yes), it proceeds to step S6 and determines that the danger level is level P2. Therefore, the control unit 3 proceeds to step S4 and performs the processing corresponding to level P2.

[0076] In step S5, if the control unit 3 determines that the object detected by the distance image sensor 2 is not a "moving object" (step S5 → No), it proceeds to step S7 and determines that the danger level is level P3. Therefore, the control unit 3 proceeds to step S4 and performs the processing corresponding to level P3.

[0077] In this way, the control unit 3 can classify objects into levels P1 to P3 based on the judgment flowchart described above. According to the first embodiment, the degree of danger can be determined according to the type of object detected by the distance image sensor 2. As a result, in this embodiment, work efficiency can be improved while ensuring safety by changing the operation of warnings, alarms, and emergency brakes according to the degree of danger.

[0078] In this embodiment, at a predetermined vehicle speed, the activation distance for the warning alert and the activation distance for the emergency brake become shorter as the level increases from low (level P3) to high (level P1).

[0079] Furthermore, the control unit 3 can appropriately select whether to perform one of the following actions: alerting (attention control), warning (warning control), or emergency braking (brake control). For example, in the case of a low level (level P3), the detected object is a stationary object, so the operator wants to compact the area close to the stationary object. In such a case, issuing warnings or alarms would result in unnecessary alarms sounding continuously, placing a heavy burden on the operator. Therefore, the control unit 3 may set the detection area 4 to omit warnings and alerts and only apply emergency braking in the case of a low level (level P3). Alternatively, the control unit 3 may set the detection area 4 to issue a warning and then apply emergency braking in the case of a low level (level P3).

[0080] Furthermore, for example, in the case of a medium level (level P2), the detected object is another vehicle (a moving object other than a person), which has a lower priority than a person. Therefore, the control unit 3 may set the detection area 4 to omit the warning and apply emergency braking after issuing an alarm. Furthermore, the control unit 3 may set the detection area 4 to perform emergency braking without issuing warnings or alarms when the level is moderate (level P2).

[0081] Furthermore, for example, in the case of a high level (level P1), the detected object is a person, and therefore has a high priority. For this reason, the control unit 3 may set the detection area 4 to issue a warning after providing a cautionary alert, and then to apply emergency braking after the warning.

[0082] Figure 7 shows the relationship between the vehicle's speed on the horizontal axis and the distance between the vehicle and the object on the vertical axis. In Figure 7, the area is divided into three regions: region 102 where the warning is activated, region 103 where the alarm is activated, and region 104 where the emergency brake is activated. The white area 101 is the region where neither the warning nor the alarm is sounded. This helps to maintain quietness in the surrounding area during nighttime work. In addition, in this embodiment, the conditions for issuing a warning or alarm for a stationary object have been narrowed (the alarm will not be triggered unless the object is quite close), so region 101 tends to be larger when dealing with a stationary object.

[0083] As shown in Figure 8, in this embodiment, when the detected object is a "person" or a "moving object," the operator can be alerted by speaker SP1 mounted around the driver's seat of the vehicle, and the obstacle (surrounding workers) G located in the direction of travel can be alerted by speaker SP2 mounted at the rear of the vehicle. Furthermore, when the detected object is a "stationary object," the operator can be alerted primarily by speaker SP1 alone.

[0084] Furthermore, if the detected object is a "person," speaker SP1 will alert the operator, and speaker SP2 will alert any obstacles (surrounding workers) G located in the vehicle's direction of travel. If the detected object is a "moving object," the alert to the operator may be modified depending on the situation. If the detected object is a "stationary object," speaker SP1 may be used to alert only the operator.

[0085] Furthermore, the control unit 3 may expand and / or shrink the detection area 4 (caution area, alarm area, emergency brake area) in accordance with each level it has been classified into. That is, the control unit 3 can change (expand or shrink) the length of the detection area 4 of the distance image sensor 2 and the width perpendicular to this length in accordance with each level. In addition, the control unit 3 can change (expand or shrink) either the length of the detection area 4 of the distance image sensor 2 or the width perpendicular to this length in accordance with each level.

[0086] As shown in Figure 9, in this embodiment, when the object to be detected is a "person", the detection area 4 of the distance image sensor 2 may be expanded in the width direction. That is, in Figure 9, the width of the detection area 4 of the distance image sensor 2 is expanded from width dimension L1 to width dimension L4. In other words, the width dimension of the detection area 4 is expanded and set to be wider than the width of the vehicle. In Figure 9, G1 represents a "person".

[0087] In this way, by setting the detection area 4 to be wider than the vehicle width, detection is possible even when a person G1 is outside the vehicle width, thereby further enhancing safety. The widthwise expansion of the detection area 4 may be increased in the order of warning, alarm, and emergency braking, or it may be increased only for emergency braking.

[0088] On the other hand, in this embodiment, if the detected object is a "stationary object," the detection area 4 of the distance image sensor 2 may be reduced in the width direction. In other words, if the detected object is a "stationary object," the degree of danger is small, and there are cases where it is desirable to compact the material close to the "stationary object," so the detection area 4 can be reduced to prioritize work efficiency.

[0089] Furthermore, as shown in Figure 10, if the detected object is a "stationary object (wall)", only one side of the detection area 4 in the width direction may be reduced. In Figure 10, since wall G2 is only on the right side in the direction of travel, the boundary on the right side of detection area 4 is set inward from the vehicle width position. Thus, the width of detection area 4 may be asymmetrical. Also, as shown in Figure 10, when the tire roller 10 turns along wall G2, detection area 4 tends to detect wall G2 more easily, leading to a higher rate of false detections. For this reason, a portion of the rear end of detection area 4 may be further reduced (changed from point B3 to point B4 in Figure 10).

[0090] Furthermore, as shown in Figure 11, if the detected object is a "stationary object (e.g., a wall)", the detection area 4 may be reduced on one side in the width direction and expanded on the other side. In Figure 11, since wall G2 is only on the right side in the direction of travel, the boundary of the detection area 4 is set to be inside the vehicle width position only on the right side. In other words, on the wall G2 side, boundary C3 is set inside the vehicle width position (vehicle width boundary) C1, which is an extension of the vehicle width. On the opposite side of wall G2, boundary C2 is set outside the vehicle width position (vehicle width boundary) C1, which is an extension of the vehicle width. The width dimension of the detection area 4 is set to the width dimension L5 from boundary C3 to boundary C2. When compaction is performed along wall G2 as in Figure 11, it is desirable to perform compaction as close to wall G2 as possible. In such cases, the detection area 4 on the wall G2 side may be reduced so as not to detect wall G2. Also, since attention will be focused on the wall G2 side, the detection area 4 on the opposite side of wall G2 may be expanded to enhance safety.

[0091] Furthermore, as shown in Figure 12A, if the detected object is only a "stationary object (e.g., a wall)", the width of the detection area 4 may be narrowed on both sides of the tip compared to the base end. In other words, only the corners of the tip end of the detection area 4 may be reduced so that the tip end becomes roughly trapezoidal. In Figure 11, compaction is performed while turning along the wall G2. As shown in the assumed movement route 21 when the tire roller 10 turns, the tire roller 10 does not come into contact with the wall G2 during this turn. However, if the tip end of the detection area 4 is rectangular (see the dashed line in Figure 12A), the wall G2 is included within the detection area 4, which may cause the emergency brake or the like to activate, potentially reducing work efficiency.

[0092] In contrast, according to the embodiment shown in Figure 12A, the corners on both sides of the leading edge of the detection area 4 are trimmed to make it narrower, so the wall G2 is not detected. This ensures safety with the detection area 4, while allowing compaction to be performed right up to the wall G2 without reducing work efficiency. The assumed movement route 21 of the tire roller 10 can be calculated by the steering angle of the handle. Therefore, the degree to which the width of the leading edge of the detection area 4 is narrowed (how much of the corners of the detection area 4 are outside the detection range) can be kept constant or can be changed in conjunction with the assumed movement route 21.

[0093] Furthermore, as shown in Figure 12B, if the detected object is a "person" or a "stationary object (e.g., a wall)", the width of the detection area 4 may be extended beyond the width of the vehicle. In other words, by extending the width of the detection area 4 beyond the width of the vehicle (see dashed line), the wall G2 and person G1 can be detected when the vehicle turns. In the embodiment shown in Figure 12B, since safety for person G1 is to be ensured, the width of the detection area 4 may be widened beyond the width of the vehicle.

[0094] Thus, the widthwise expansion or contraction of the detection area 4 can be appropriately changed based on the type of object detected, whether safety is prioritized or work efficiency is prioritized, etc.

[0095] In this embodiment, objects are detected by the distance image sensor 2, but this is not the only method. For example, "people" and "objects" may be determined by a camera, AI camera, template matching, etc.

[0096] In this embodiment, objects are detected by the distance image sensor 2, but this is not limited to this. For example, "people" and "objects" may be determined by a camera, AI camera, template matching, etc. Also, when using LIDAR (Light Detection and Ranging), a reflective vest worn at the work site may be determined as a "person".

[0097] When determining that a "moving object" is the object to be detected, the relative speed and direction of movement of the object may be detected. Alternatively, these may be calculated by comparing them with the vehicle's direction of travel, speed, and direction of travel. Furthermore, when the vehicle is driving autonomously, if the distance image sensor 2 detects the presence of a "person" around the vehicle, the engine driving the vehicle may be prevented from starting, or the vehicle may be prevented from starting.

[0098] [Second Embodiment] Next, a construction vehicle according to the second embodiment of the present invention will be described. Note that components identical to those in the first embodiment described above are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0099] In this embodiment, multiple levels are set according to the degree of danger of the object detected by the distance image sensor 2, and the length of the detection area 4 of the distance image sensor 2, and / or the width perpendicular to the length, are changed according to each level. In this embodiment, the degree of danger is determined by the relative speed between the vehicle and the other vehicle (opposing vehicle).

[0100] Figures 13(a) to (d) are schematic plan views showing the levels divided according to the relative speed between the vehicle and the opposing vehicle. In Figures 13(a) to (d), the left side of the diagram represents the vehicle, and the right side represents the opposing vehicle. As shown in Figure 13, compaction machines such as tire rollers 10 may have multiple vehicles traveling in parallel in the direction of travel to perform compaction. In this compaction method, there is a risk of contact between the vehicle and the opposing vehicle depending on the direction of travel and speed. Therefore, in this compaction method, it is desirable to ensure safety by preventing contact between each tire roller 10, and to improve work efficiency by preventing unnecessary alarm sounds or emergency brake activation.

[0101] In this embodiment, after the distance image sensor 2 (object sensor) detects that the object is a "moving object other than a person" (the opposing vehicle), instead of processing it uniformly, the system categorizes it into levels based on the relative speed between the vehicle and the opposing vehicle.

[0102] More specifically, in this embodiment, levels are assigned based on the relative speed between the vehicle and the other vehicle, and the caution area, warning area, and emergency braking area are changed according to each level. In the following example, a smaller number indicates a higher level and higher priority than a larger number.

[0103] Furthermore, in this embodiment, the control unit 3 is equipped with a "relative speed acquisition means" as a functional unit. The "relative speed acquisition means" acquires the relative speed between the vehicle and the other vehicle. For example, a relative speed detection sensor can be used for the "relative speed acquisition means". The relative speed may be acquired by calculating the vehicle's own speed and the other vehicle's speed, or it may be acquired by information provided by a third party. After the control unit 3 detects that the object is a "moving object other than a person" (the other vehicle) using the distance image sensor 2 (object sensor), it performs level classification based on the acquired relative speed.

[0104] (Example of level classification) Figure 13(d) shows the Level R4 situation. Here, the vehicle is traveling backward at 4 km / h, and the other vehicle is traveling forward at 6 km / h. In other words, the other vehicle is on the extension of the direction of travel of the vehicle, and the other vehicle is traveling at a higher speed. Relative speed is defined as "+" for the vehicle moving away from the vehicle and "-" for the vehicle moving closer. In Figure 13(d), the relative speed is "+2".

[0105] Thus, the relative speed is "+2", and the distance between your vehicle and the other vehicle gradually increases, so there is no risk of contact. Therefore, this case is designated as Level R4. As shown in Figure 13(d), in Level R4, there is no risk of contact, so detection area 4 is not set. Also, when the relative speed is "0", there is no risk of contact, so it is also designated as Level R4. In other words, if the relative speed is "0" or greater, it is designated as Level R4.

[0106] Figure 13(c) shows the Level R3 condition. Here, your vehicle is traveling backward at 4 km / h, and the other vehicle is traveling forward at 6 km / h. In other words, the other vehicle is on the extension of your vehicle's direction of travel, and your vehicle is traveling at a higher speed. In Figure 13(c), the relative speed is "-2".

[0107] As described above, the relative speed is "-2", and the distance between the vehicle and the other vehicle gradually decreases, thus creating a risk of collision. Therefore, this case is designated as Level R3. When the object detected within the projection range by the distance image sensor 2 is determined to be a "moving object other than a person (the other vehicle)" and the level is R3, the length of the detection area 4 for activating the emergency brake is set to 1.3m from the rear of the vehicle, and the length of the detection area 4 for activating the alarm is set to 2.1m from the rear of the vehicle. No warning area is set for alerting the driver. This is because the degree of danger based on relative speed is small, and therefore a warning area is not provided to reduce the burden on the operator (a warning is issued even though the degree of danger is low). In the example in Figure 13(c), the other vehicle is not within the alarm area, so in this state, the control unit 3 does not perform any alarm processing.

[0108] Figure 13(b) shows the Level R2 condition. Here, your vehicle is traveling backward at 4 km / h, and the other vehicle is stopped. In Figure 13(b), the relative speed is "-4".

[0109] As described above, the relative speed is "-4", and the distance between the vehicle and the other vehicle gradually decreases, creating a risk of collision. Furthermore, since the relative speed is greater than that of Level R3, this case is classified as Level R2. When the object detected within the projection range of the distance image sensor 2 is determined to be a "moving object other than a person (other vehicle)" and the level is R2, the length of the detection area 4 for activating the emergency brake is set to 1.9m from the rear of the vehicle, and the length of the detection area 4 for activating the alarm is set to 3.5m from the rear of the vehicle. In other words, since Level R2 is more dangerous than Level R3, the lengths of the alarm area and emergency brake area are set to be larger. Similar to Level R3, no warning area is set to alert the driver. Note that in the example in Figure 13(b), the other vehicle is not within the alarm area, so in this state, the control unit 3 does not perform any alarm processing.

[0110] Figure 13(a) shows the Level R1 condition. Here, your vehicle is traveling backward at 4 km / h, and the other vehicle is traveling backward (towards approaching) at 2 km / h. In Figure 13(a), the relative speed is "-6".

[0111] As shown above, the relative speed is "-6", and the distance between the vehicle and the other vehicle decreases rapidly, creating a risk of collision. Furthermore, since the relative speed is greater than that of Level R2, this case is classified as Level R1. When the object detected within the projection range by the distance image sensor 2 is determined to be a "moving object other than a person (other vehicle)" and is classified as Level R1, the length of the detection area 4 for activating the emergency brake is set to 2.5m from the rear of the vehicle, the length of the detection area 4 for activating the alarm is set to 5.0m from the rear of the vehicle, and the warning area for issuing a warning is set to 10m. In other words, since Level R1 is more dangerous than Level R2, a warning area is set, and the lengths of the alarm area and emergency brake area are set to be larger. In the example in Figure 13(a), the other vehicle is within the warning area, so the control unit 3 performs a warning process.

[0112] The aforementioned example of level division is merely an example; for example, the relative velocity thresholds for each level can be set as appropriate. The length of the detection area 4 for each level can also be set as appropriate. Furthermore, in this embodiment, the detection area 4 may be expanded or reduced in the width direction.

[0113] Next, a flowchart for setting the emergency operating distance based on the relative speed between your vehicle and the other vehicle will be explained in detail below, based on Figure 14.

[0114] First, in step S11, the following predetermined values ​​are set. Vm; Vehicle's speed (detected by a vehicle speed sensor installed on the vehicle) Vr; Measurement / Calculation of Relative Velocity (Detection Sensor) Vset1, 2; arbitrary threshold (usually 0 is fine) The relative speed Vr is calculated as V0 (the other vehicle's speed) - Vm (your vehicle's speed) (see Figure 15). In this way, relative speed can be obtained by calculating your own vehicle's speed and the other vehicle's speed.

[0115] In step S12, the control unit 3 monitors the relative velocity Vr and determines whether the relative velocity is less than Vset1. Normally, Vset1 = 0, so if the relative velocity is a negative value less than 0 (step S12 → Yes), the process proceeds to step S13. Conversely, as will be described later, if the relative velocity is a value greater than or equal to 0 (positive) (step S12 → No), the process proceeds to step S20.

[0116] When the relative speed is a negative value less than 0, the other vehicle is approaching your vehicle (step S13). The control unit 3 also calculates the other vehicle's travel speed V0 using the following equation 1 (step S14). V0=Vr+Vm (Equation 1).

[0117] Next, in step 15, the control unit 3 monitors the direction of travel of the opposing vehicle and determines whether the opposing vehicle's speed V0 is less than Vset2. Normally, Vset2 = 0, so if the opposing vehicle's speed is a negative value less than 0 (step S15 → Yes), the system proceeds to step S16. In step S16, the opposing vehicle is traveling towards the system, and the level is set to R1.

[0118] In step 15, if the other vehicle's speed is 0 or greater (step S15 → No), proceed to step S17. In step S17, determine whether the other vehicle is stopped (V0=0?) or not.

[0119] In step S17, when the control unit 3 determines that the other vehicle is stopped (V0=0) (step S17→Yes), it determines that its own vehicle is moving towards the other vehicle and sets the level to R2 (step S18).

[0120] Furthermore, in step S17, if the control unit 3 determines that the other vehicle is traveling in the same direction as its own vehicle but at a slower speed than its own vehicle (step S17 → No), it sets the level to R3 (step S19).

[0121] On the other hand, if the relative speed is greater than or equal to 0 (positive) in step S12 (step S12 → No), the system proceeds to step S20. In step S20, if the other vehicle is moving away from the other vehicle, or is traveling at a very low speed that the system does not want to trigger, the control unit 3 does not activate the emergency brake and / or alarm (level R4).

[0122] Thus, in this embodiment, the control unit 3 can classify the relative speed between its own vehicle and the other vehicle into levels R1 to R4. The control unit 3 may expand and / or shrink each area (caution area, warning area, emergency brake area) in accordance with each level it has classified. That is, the control unit 3 can change (expand or shrink) the length of the detection area 4 of the distance image sensor 2 and the width perpendicular to this length in accordance with each level. In addition, the control unit 3 can change (expand or shrink) either the length of the detection area 4 of the distance image sensor 2 or the width perpendicular to this length in accordance with each level.

[0123] In this embodiment, the degree of danger can be determined according to the acquired relative speed. This allows for improved work efficiency while ensuring safety by changing the operation of warnings, alarms, and emergency brakes according to the degree of danger.

[0124] In this embodiment, when the relative speed between your vehicle and the other vehicle is negative (-), the length of the detection area of ​​the distance image sensor 2, and / or the width perpendicular to the length, is set to be larger than when the relative speed is zero or positive (+). This enhances safety.

[0125] Furthermore, in this embodiment, when the relative speed between your vehicle and the other vehicle is negative (-), the larger the absolute value of the relative speed, the larger the length of the detection area of ​​the distance image sensor 2 and / or the width perpendicular to the length are set to be. This further enhances safety.

[0126] Furthermore, in this embodiment, if the relative speed between your vehicle and the other vehicle is positive (+), the control unit 3 does not perform any control such as warning, alarm, or emergency braking. This improves work efficiency.

[0127] Furthermore, in this embodiment, relative speed is calculated by combining the vehicle's own speed and the other vehicle's speed, but the invention is not limited to this. Relative speed may also be obtained based on detection signals from relative speed detection sensors (not shown) installed on the vehicle or the other vehicle. In addition, relative speed may be obtained through information provided by a third party.

[0128] Next, the specific calculation methods for Level R2 and Level R3 will be explained based on Figure 14. It will be assumed that both your vehicle and the other vehicle are traveling in the same direction.

[0129] First, the time Ta required to decelerate your vehicle's speed to the speed of the other vehicle can be calculated using the following formula. Ta = (V0 - Vm) / α However, "α" refers to the acceleration (deceleration) when the emergency brake is applied.

[0130] Next, the required distance La for emergency braking can be calculated using the following formula. La=(V0 2 -Vm 2 ) / (2α)

[0131] Next, the distance at which the emergency brakes are activated can be calculated using the following formula. JudgA=La+Ka However, "Ka" refers to the safety correction factor (f(Vm)). The correction factor (f(Vm)) is a function of the vehicle's speed. For example, even if the relative speed is the same, if the vehicle's speed or the other vehicle's speed is high, the kinetic energy is also high, resulting in a longer braking distance. Conversely, if the vehicle's speed or the other vehicle's speed is low, the opposite is true. Taking this effect into account, the correction factor is set so that the distance at which emergency braking is activated can be changed.

[0132] Figure 17(a) is a characteristic diagram showing the relationship between time and speed for both your vehicle and the other vehicle from the moment your vehicle's emergency brakes are applied, and Figure 17(b) is a characteristic diagram showing the relationship between time and accumulated distance for both your vehicle and the other vehicle from the moment your vehicle's emergency brakes are applied. In Figures 17(a) and 17(b), solid lines represent your vehicle, and dashed lines represent the other vehicle.

[0133] The opposing vehicle is traveling in the same direction ahead of your vehicle, and the initial distance between your vehicle and the opposing vehicle is 1.5m (see Figure 17(b)). The opposing vehicle's speed is 3km / h, and your vehicle's speed is 6km / h (see Figure 17(a)). Furthermore, your vehicle's emergency brakes are activated at time 0.0 on the horizontal axis (see the "Brake Activation" description in Figures 17(a) and (b)).

[0134] As shown in Figure 17(a), activating the emergency brakes of your vehicle causes your vehicle's speed to decrease linearly until it comes to a complete stop (speed 0.0). The other vehicle's speed remains constant at 3 km / h. At approximately 0.7 seconds on the horizontal axis, the characteristic lines of your vehicle and the other vehicle intersect at a crossover point (CP).

[0135] As shown in Figure 17(b), when the time (hours) at the crossing point CP in Figure 17(a) is approximately 0.7 seconds, the distance between the opposing vehicle and your vehicle is minimized.

[0136] In this invention, a first embodiment in which multiple levels are set according to the type of object, and a second embodiment in which multiple levels are set according to the relative speed between the vehicle and the other vehicle are described separately. However, these first and second embodiments may be combined to set multiple levels. [Explanation of Symbols]

[0137] 1. Obstacle detection device 2. Distance image sensor (object sensor) 3. Control Unit (Relative Velocity Acquisition Means) 4. Detection Area 5. Non-detection range 6. Braking means 7. Vehicle speed sensor 10. Tire Roller (Construction Vehicle) G Obstacle G1 people G2 wall

Claims

1. A construction vehicle having a braking mechanism for stopping the wheels, An object sensor that detects an object, A control unit that activates the braking means under predetermined conditions when a detection signal is output from the object sensor, Equipped with, The control unit is configured to have multiple levels set according to the degree of danger of the object detected by the object sensor, and is characterized by changing the length of the detection area of ​​the object sensor and / or the width perpendicular to the length in accordance with each level of the control unit.

2. In the construction vehicle according to claim 1, A construction vehicle characterized in that the aforementioned level of risk is classified into levels according to the type of object.

3. In the construction vehicle according to claim 2, A construction vehicle characterized in that each of the aforementioned levels is set to a low level with a low degree of risk for stationary objects other than people, a medium level with a moderate degree of risk for moving objects other than people, and a high level with a high degree of risk for people.

4. In the construction vehicle described in claim 3, A construction vehicle characterized in that the control unit performs brake control by the braking means when the level is low, performs warning control and then brake control by the braking means when the level is medium, performs caution control and then warning control when the level is high, and further performs brake control by the braking means after the warning control.

5. In the construction vehicle described in claim 3, The construction vehicle is characterized in that the control unit performs a warning control when the level is low, and then performs brake control using the brake means when the level is medium.

6. In the construction vehicle according to claim 2, A construction vehicle characterized in that the detection area of ​​the object sensor is narrower at the tip end than at the base end.

7. In the construction vehicle according to claim 1, The aforementioned level of risk is characterized by being categorized into levels based on the relative speed between the vehicle and the object.

8. In the construction vehicle described in claim 7, When the relative speed between the vehicle and the aforementioned object is defined as positive for the side moving away from each other and negative for the side moving towards each other, A construction vehicle characterized in that, when the relative speed is negative, the length of the detection area of ​​the object sensor and / or the width perpendicular to the length are set to be larger than when the relative speed is zero or positive.

9. In the construction vehicle described in claim 7, When the relative speed between the vehicle and the aforementioned object is defined as positive for the side moving away from each other and negative for the side moving towards each other, A construction vehicle characterized in that, when the relative velocity is negative, the length of the detection area of ​​the object sensor and / or the width perpendicular to the length are set to be larger as the absolute value of the relative velocity increases.

10. In the construction vehicle described in claim 7, When the relative speed between the vehicle and the aforementioned object is defined as positive for the side moving away from each other and negative for the side moving towards each other, A construction vehicle characterized by not performing any attention control, warning control, or brake control when the relative speed is positive.

11. In the construction vehicle described in claim 7, The aforementioned object is a construction vehicle characterized by being a moving object other than a person.

12. In the construction vehicle described in claim 7, The construction vehicle is characterized in that the relative speed is obtained based on detection signals from relative speed detection sensors installed on the vehicle itself or other vehicles.

13. In the construction vehicle described in claim 7, The construction vehicle is characterized in that the aforementioned relative speed is obtained by calculating the vehicle's own speed and the other vehicle's speed.

14. In the construction vehicle described in claim 7, The construction vehicle is characterized in that the aforementioned relative speed is obtained through information provided by a third party.

15. In the construction vehicle described in claim 7, A construction vehicle characterized in that each of the aforementioned levels is set to a low level of low risk, a medium level of moderate risk, and a high level of high risk, depending on the relative speed.

16. In the construction vehicle according to claim 15, A construction vehicle characterized in that the control unit performs brake control by the braking means when the level is low, performs warning control and then brake control by the braking means when the level is medium, performs caution control and then warning control when the level is high, and further performs brake control by the braking means after the warning control.

17. In the construction vehicle according to claim 15, The construction vehicle is characterized in that the control unit performs a warning control when the level is low, and then performs brake control using the brake means when the level is medium.

18. In the construction vehicle described in claim 7, A construction vehicle characterized in that the detection area of ​​the object sensor is narrower at the tip end than at the base end.

Images