Mobile vehicle and driving support system for mobile vehicle

Abstract

To provide a mobile vehicle driving assistance device which enables generation of a good travel route in consideration of road surface conditions, and to provide a mobile vehicle that enables good travel.SOLUTION: A mobile vehicle driving assistance device is provided, comprising a detector for detecting road conditions and a control unit for estimating the location of the mobile vehicle. The detector is mounted on the mobile vehicle, and the control unit is configured to create a road surface database containing a plurality of locations in an area the vehicle is traveling in, in association with corresponding score information indicative of road surface conditions detected by the detector.SELECTED DRAWING: Figure 1

Description

Technical Field

[0005]

[0001] The present invention relates to a moving body and a driving support device for the moving body.

Background Art

[0002] Conventionally, an optimal movement path of a moving body has been generated using a path planning algorithm. Further, Patent Document 1 discloses a search program for a path on which an autonomous mobile robot travels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0007] The mobile body according to the present invention is Movement is based on score information that represents the road surface conditions. It is a mobile object, A detector that detects road surface conditions, A control device for estimating the position of the moving object and a communication unit capable of communicating with it, Equipped with, The detector is mounted on the mobile body, The control device creates a road surface database by associating score information representing the road surface conditions detected by the detector with multiple locations on the area in which the moving body is moving. The control device creates a cost map showing the difficulty of movement for each part on the area based on the road surface database, The control device changes the relationship between the score information in the road surface database and the difficulty of movement in the cost map based on the conditions. The mobile unit moves with driving assistance based on the cost map. . [Effects of the Invention]

[0008] According to the present invention, road surface conditions can be detected by utilizing the movement of a mobile object, and a route database can be created in which multiple locations are associated with road surface conditions. Furthermore, this road surface database enables the generation of a good travel route that takes road surface conditions into account. In addition, the mobile object can achieve good movement based on score information. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing a mobile body and its driving support device according to an embodiment of the present invention. [Figure 2] This figure shows an example of a road surface database. [Figure 3] Figure (A) shows an example of a cost map, and Figure (B) is a magnified view of a part of it. [Figure 4] This figure shows an example of a good path generated by the control unit using a cost map. [Figure 5] This figure shows the cost map (A) created when the moving object meets the second condition and the cost map (B) created when it meets the first condition.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] FIG. 1 is a block diagram showing a moving body 50 and its driving support device 100 according to an embodiment of the present invention.

[0012] The driving support device 100 of the moving body 50 according to the present embodiment includes a road surface condition detector 111 mounted on the moving body 50, a measuring instrument 113 for position estimation mounted on the moving body 50, a road surface database 130, a cost map 140, and a control device 120 for creating a good route 150 used for driving support.

[0013] The moving body 50 is a cargo handling machine that transports loads, and more specifically, is a forklift. The moving body 50 may have an autonomous configuration that can move without a driver, or may have a configuration in which the driver moves while receiving support information.

[0014] The detector 111 detects road surface conditions that can be used to determine the suitability of passage, such as the unevenness, slipperiness, and degree of mud of the road surface. As the detector 111, at least one of an inertial measurement unit (IMU), a camera that photographs the road surface, a distance measuring instrument (such as Light Detection And Ranging) that scans the road surface, and a wheel speed sensor can be applied. The inertial measurement unit can detect the sway of the moving body 50 in the vertical, horizontal, and lateral directions, and can detect the unevenness of the road surface from the sway. The camera can acquire a photographed image of the road surface, and can estimate the road surface condition by analyzing the photographed image or using artificial intelligence for analysis. The distance measuring instrument can measure the unevenness of the road surface based on the scan data of the road surface. The wheel speed sensor can detect the slipperiness of the road surface by discriminating the slip of the wheels from the difference in the wheel speeds of a plurality of wheels. Note that the detector 111 is not limited to the above examples, and any configuration may be applied as long as it can detect the road surface condition.

[0015] The measuring instrument 113 may be a camera that acquires images of the surroundings, a receiver for a positioning system that detects position using satellite radio waves or base station radio waves, or a wheel speed log sensor that acquires wheel speed logs. If the measuring instrument 113 is a camera, the position of the moving object 50 can be estimated based on SLAM (Simultaneous Localization and Mapping) from the surrounding images acquired by the measuring instrument 113 (for example, by estimating the current position based on a comparison between the surrounding images or shape detected during prior map generation and the currently detected surrounding images or shape). If the measuring instrument 113 is the above-mentioned receiver, the position of the moving object 50 can be directly estimated from the positioning results of the positioning system. Furthermore, if the measuring instrument 113 is a wheel speed log sensor, the position of the moving object 50 can be estimated from the integration of the relative movement vectors of the moving object 50 based on the wheel speed logs. Note that the measuring instrument 113 is not limited to the above examples, and any configuration that can estimate the position of the moving object 50 may be applied.

[0016] The mobile unit 50 has a communication unit 53, and can send detection data from the detector 111 and measurement data from the measuring instrument 113 to the control device 120 via the communication unit 53.

[0017] The control device 120 is a computer that executes programs and includes a storage device 123 that stores the road surface database 130 and the cost map 140, and a communication unit 125 that exchanges data with the mobile body 50.

[0018] For the communication section 53, 125, for example, a wireless communication device can be applied.

[0019] <Road surface database 130> Figure 2 shows an example of the road surface database 130.

[0020] In order to create the road surface database 130, the control device 120 first receives measurement data from the measuring instrument 113 sequentially and estimates the position of the moving body 50 using the estimation method described above.

[0021] Furthermore, the control device 120 sequentially receives detection data from the detector 111 and creates score information representing the road surface conditions based on the detection data. The score information is a value that represents, for example, whether the road surface is good or bad for the moving object 50 to move on. The score information should be created such that, for example, a large value indicates a high degree of poorness when the road surface is uneven, the unevenness is steep, or the road surface is slippery, and a small value indicates a low degree of poorness when the road surface is uneven, the unevenness is gentle, or the road surface is not slippery. The score information may be a discrete value such as an integer value from 1 to 10, or a continuous value. In addition, the score information may be a set of values ​​that can represent goodness or badness from multiple perspectives (for example, a combination of a first score information indicating the magnitude of vibration and a second score information indicating slipperiness). In the following, the score information will be assumed to be a single value, and the higher the degree of poorness of the road surface, the larger the value will be.

[0022] Then, as shown in Figure 2, the control device 120 registers the date and time, the estimated position of the moving object 50 (X coordinate and Y coordinate position), and score information as a set of record data in the road surface database 130. This collection of record data constitutes the road surface database 130. Once the road surface database 130 is created, it becomes possible to understand the road surface conditions at multiple locations within the area where the moving object 50 is moving, using the score information from the database.

[0023] A set of record data in the road surface database 130 may include attitude data of the moving body 50 (e.g., yaw angle). The moving body 50 may be equipped with an IMU (Inertial Measurement Unit), and the attitude data may be calculated from the IMU's measurement data. Alternatively, the driver assistance device 100 may be equipped with a camera that can provide an overview of the entire movement area of ​​the moving body 50, and the attitude data of the moving body 50 may be calculated from the image from the camera.

[0024] With the attitude data available, the control device 120 can calculate the direction in which the moving body 50 is moving. Therefore, if the detector 111 is configured to detect road surface conditions using video or scan data, the control device 120 can calculate which direction the road surface conditions detected by the detector 111 are located relative to the moving body 50. Consequently, the control device 120 can accurately determine the location of the road surface conditions detected by the detector 111.

[0025] Furthermore, the presence of attitude data allows the control device 120 to accurately calculate the trajectory of the wheels as the mobile body 50 moves. Therefore, if the detector 111 is configured to detect road surface conditions based on vibrations of the mobile body 50, the control device 120 can accurately determine which location of road surface conditions the detector 111 has detected.

[0026] The control device 120 receives detection data and measurement data from the mobile body 50 when the mobile body 50 is working or when the mobile body 50 is moving for reasons other than work, and continuously registers record data in the road surface database 130. When the mobile body 50 is configured to perform cargo handling, "working" means when the mobile body 50 is performing cargo handling (transporting cargo or moving back to pick up cargo). When the mobile body 50 is configured to perform cargo handling, "movement for reasons other than work" means movement other than cargo handling, and may also be movement for creating the road surface database 130.

[0027] Furthermore, if the mobile body 50 moves over the same location multiple times, multiple score entries for approximately the same location will be registered in the road surface database 130. In this case, the control device 120 may be configured to treat the most recent score entry as the score entry for that location. Alternatively, it may be configured to extract a predetermined number of score entries from among multiple score entries for approximately the same location, perform statistical processing (e.g., averaging or excluding outliers), and then treat the resulting score entry as the score entry for that location. In other words, the control device 120 may update the score entry associated with the first location based on the road surface conditions detected in the first period, based on the road surface conditions of the first location detected in a second period that follows the first period.

[0028] Road surface conditions can change over time. For example, uneven road surfaces may be compacted by the movement of the mobile body 50, or muddy areas may dry up. Therefore, by continuously updating the score information in the road surface database 130 as described above, it is possible to obtain a road surface database 130 that better reflects the road surface conditions at each point in time, in response to the changing road surface conditions. Then, by using this road surface database 130 to perform the driving assistance described later, it is possible to realize driving assistance that better reflects the road surface conditions at each point in time.

[0029] <Cost Map> Figure 3 shows an example of cost map 140 (A), and a magnified view of a part of it (B).

[0030] The control device 120 creates a cost map 140 based on the road surface database 130. The cost map 140 is a map that shows the difficulty of movement of each part on area A. This difficulty of movement will be referred to as the "cost value" below, and a higher cost value indicates a higher degree of difficulty in movement. Area A corresponds to the workplace where the mobile unit 50 works, and if the mobile unit 50 is a cargo handling machine, it corresponds to a cargo handling area. The cost map 140 may also be configured such that each part on area A is represented by a fine grid gd, and a cost value is shown for each grid gd, as shown in Figure 3(B).

[0031] The cost values ​​for each part of the cost map 140 may be discrete values, such as integers from 1 to 10, or continuous values. The control device 120 determines the cost values ​​for each part based on the score information in the road surface database 130. Specifically, if the score information for a location registered in the road surface database 130 is high, the control device 120 increases the cost value for that location; if the score information is low, it leaves the cost value for that location unchanged or decreases it.

[0032] The control device 120 may determine the cost value of the cost map 140 by comprehensively considering the difficulty of moving each part based on the layout of area A (boundaries of area A, layout of walls and pillars, etc.) and the difficulty of moving each part based on various other factors, in addition to the score information. For locations not registered in the road surface database 130, the control device 120 may maintain the cost value determined based on the layout or other factors, or it may perform a predetermined addition or subtraction to the said cost value.

[0033] As shown in Figure 3(A), the cost value calculation process described above results in a cost map 140 in which the cost values ​​for areas a1 and a2, where the road surface conditions are poor, are increased.

[0034] <Good route> Figure 4 shows an example of a good route generated by the control device 120 using the cost map 140.

[0035] The control device 120 uses a cost map 140 and a path planning algorithm to create a suitable route 150 for the movement of the mobile unit 50. Various known algorithms can be applied as the path planning algorithm. The path planning algorithm extracts a suitable route 150 that connects the starting point P0 to the ending point P1, such that the sum of the cost values ​​along the route is small. The suitable route 150 avoids locations with large score information (locations with poor road conditions) and minimizes the travel distance. The control device 120 sends the information of the created suitable route 150 to the mobile unit 50. The above starting and ending points correspond to the cargo receiving point and cargo transport destination when the mobile unit 50 is a cargo handling machine.

[0036] The mobile unit 50 receives driving support information, including information on a good route 150, from the control device 120 via the communication unit 53. The mobile unit 50 then moves based on this information. That is, if the mobile unit 50 is equipped with an autonomous driving system 55, the autonomous driving system 55 automatically drives along the good route 150. Also, if the mobile unit 50 is equipped with a display device 56 that outputs driving support information and is driven by a driver, the mobile unit 50 outputs information on the good route 150 to the control device 120, and the driver drives the mobile unit 50 relying on the information on the good route 150. Instead of, or in addition to, driving support by display, driving support by voice or driving assist functions may be provided. Driving support using the good route 150 enables the mobile unit 50 to move in a manner suitable for the road surface conditions in area A.

[0037] <Creating a cost map 140 based on conditions> When the mobile body 50 is loaded, it is undesirable for vibrations of a certain magnitude or greater to be applied to the mobile body 50 during its movement. If vibrations of a certain magnitude or greater may occur at a location where "score information ≥ first value", the above can be rephrased as saying that when the mobile body 50 is loaded, it is unsuitable for it to pass through a location with score information equal to or greater than the first value.

[0038] On the other hand, if the mobile body 50 is not carrying a load, a certain degree of vibration during its movement is not a problem, but a larger vibration can lead to an undesirable situation. If a larger vibration occurs at a position where "score information ≥ second value", the above can be rephrased as saying that when the mobile body 50 is not carrying a load, it is not suitable for it to pass through a position with score information of second value or higher.

[0039] Thus, the relationship between the score information in the road surface database 130 and the difficulty of movement in the cost map 140 changes depending on the conditions. Therefore, the control device 120 can create a cost map 140 that is appropriate to the conditions by changing the relationship between the score information in the road surface database 130 and the cost values ​​in the cost map 140 according to the conditions.

[0040] Next, we will explain the process by which the control device 120 creates cost maps 140a and 140b according to the conditions. Below, we will show an example in which a first condition indicating the presence of cargo and a second condition indicating the absence of cargo are applied as conditions.

[0041] Figure 5 shows cost map 140a, which is created when the mobile unit 50 meets the second condition, and cost map 140b, which is created when it meets the first condition, respectively. In Figures 5(A) and 5(B), areas with high cost values ​​are indicated by shading and solid lines.

[0042] The control device 120 further includes a condition input function in order to create a cost map 140 according to the conditions. The condition input function may be configured to send information indicating the conditions from the mobile body 50 to the control device 120 by data transmission via the communication units 53 and 125, or it may be configured to input information indicating the conditions to the control device 120 by manual operation by an operator or driver.

[0043] When the control device 120 receives the first condition that there is a load, it sets the threshold for the score information used to determine the cost value to a low first threshold, such as the first value mentioned above. The control device 120 then creates a cost map 140b such that the cost value increases at locations with score information values ​​greater than the first threshold, and decreases at locations with score information values ​​less than the first threshold. As shown in Figure 5(B), the cost map 140b created in this way is a map in which the cost value increases at locations with moderate to severe road surface conditions. The good route 150b created based on this cost map 140b is a travel route that avoids areas with moderately severe road surface conditions.

[0044] On the other hand, when the second condition of "no cargo" is input, the control device 120 sets the threshold for score information used to determine the cost value to a second threshold that is higher than the first threshold. The control device 120 then creates a cost map 140a such that the cost value is higher at locations with score information values ​​greater than the second threshold, and lower at locations with score information values ​​less than the second threshold. As shown in Figure 5(A), the cost map 140a created in this way is a map in which the cost value is higher at locations with very poor road conditions, and the cost value is kept low at locations with moderately poor road conditions. The good route 150a created based on this cost map 140a is a short travel route that passes through areas with moderately poor road conditions.

[0045] Then, the control device 120 provides driving support for the mobile body 50 according to the favorable paths 150a and 150b, thereby providing driving support that is appropriate to the state of the load on the mobile body 50.

[0046] In the example above, the condition of whether or not there is cargo was applied, but the above conditions may include various cargo-related conditions such as the amount of cargo, the height of the cargo, and the degree of unevenness in the arrangement of the cargo. Furthermore, any conditions other than cargo that relate to the degree of poor road conditions that should be avoided may be included.

[0047] As described above, the driving support device 100 for the mobile body 50 of this embodiment includes a detector 111 for detecting road surface conditions and a control device 120 for estimating the position of the mobile body 50. The detector 111 is mounted on the mobile body 50, and the control device 120 creates a road surface database 130 that associates multiple locations in area A with score information representing the road surface conditions detected by the detector. Therefore, the control device 120 can grasp the road surface conditions at multiple locations on area A where the mobile body 50 is moving using the road surface database 130, and can provide driving support according to the road surface conditions.

[0048] Furthermore, according to the driving support device 100 of the mobile body 50 of this embodiment, the control device 120 creates a cost map 140 that shows the difficulty of moving each part on area A based on the road surface database 130. Therefore, the cost map 140 makes it possible to create a good route 150 that takes road surface conditions into account, and driving support according to road surface conditions can be realized.

[0049] Furthermore, according to the driving support device 100 for the mobile body 50 of this embodiment, the detector 111 includes at least one of an inertial measuring instrument, a camera for photographing the road surface, a rangefinder for scanning the road surface, and a wheel speed sensor for the mobile body 50. This configuration also enables the detection of road surface conditions when the mobile body 50 is moving.

[0050] Furthermore, according to the driving support device 100 of the mobile body 50 of this embodiment, the control device 120 handles the road surface database 130 such that the score information registered in the road surface database 130 is updated based on the road surface conditions detected thereafter. Therefore, even if the road surface conditions change over time, the road surface database 130 can reflect the changed road surface conditions. And by providing driving support based on such a road surface database 130, driving support that responds to changes in road surface conditions can be realized.

[0051] Furthermore, according to the driving support device 100 of the mobile body 50 of this embodiment, the control device 120 changes the relationship between the score information of the road surface database 130 and the cost value (difficulty of movement) of the cost map 140 based on the conditions, and creates a cost map 140. Even if the road surface conditions are the same, depending on the state of the cargo, it may be difficult to pass through or it may be possible to pass through without any problems. In other words, the relationship between the road surface conditions and the difficulty of movement may change depending on the conditions. With the above configuration, it is possible to create a cost map 140 that is suitable for the conditions in response to such cases.

[0052] Specifically, the control device 120 calculates a good route 150 for the mobile body 50, which is a cargo handling machine, and inputs the status of the cargo held by the mobile body 50 (for example, whether there is a load or not) as one of the above conditions, and creates a cost map 140. Therefore, the control device 120 can provide driving support that is appropriate to the status of the cargo.

[0053] Furthermore, according to the mobile body 50 of this embodiment, since movement is performed based on score information representing road surface conditions, optimal movement according to road surface conditions can be achieved.

[0054] Embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. For example, in the above embodiments, an example was described in which the mobile body is a cargo handling machine. However, the mobile body may be a mobile robot that provides various services and does not transport cargo. Also, in the above embodiments, the control device 120 is shown to be located away from the mobile body 50, but the control device 120 may be mounted on the mobile body 50. Alternatively, the control device 120 may be provided on a cloud located away from the area A in which the mobile body 50 moves. Furthermore, details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0055] 50 Mobile Units 53 Communications Department 55 Autonomous driving systems 56 Display device 100 Driving support devices 111 detector 113 Measuring Instruments 120 Control device 123 Storage device 125 Communications Department 130 Road surface database 140, 140a, 140b Cost Map 150, 150a, 150b Good routes Area A a1, a2 Areas with poor road surface conditions gd grid

Claims

1. A detector that detects road surface conditions, A control device for estimating the position of a moving object, Equipped with, The detector is mounted on the mobile body, The control device creates a road surface database by associating score information representing the road surface conditions detected by the detector with multiple locations on the area in which the moving body is moving. The control device creates a cost map showing the difficulty of movement for each part on the area based on the road surface database, The control device changes the relationship between the score information in the road surface database and the difficulty of movement in the cost map based on the conditions. The mobile body moves with driving assistance based on the cost map. A driving assistance system for mobile vehicles.

2. The detector includes at least one of the following: an inertial measuring device, a camera for photographing the road surface, a rangefinder for scanning the road surface, and a wheel speed sensor for the moving object. A driving support device for a mobile body according to claim 1.

3. The control device updates the score information associated with the first position based on the road surface conditions detected in the first period, based on the road surface conditions of the first position detected in the second period which is later than the first period. A driving support device for a mobile body according to claim 1 or claim 2.

4. The control device calculates the best path for the moving object based on the cost map, The aforementioned mobile body is a cargo handling machine, The aforementioned condition is the state of the load held by the moving body. A driving support device for a mobile body according to claim 1 or claim 2.

5. A mobile body that moves based on score information representing road surface conditions, A detector that detects road surface conditions, A control device for estimating the position of the moving object and a communication unit capable of communicating with it, Equipped with, The detector is mounted on the mobile body, The control device creates a road surface database by associating score information representing the road surface conditions detected by the detector with multiple locations on the area in which the moving body is moving. The control device creates a cost map showing the difficulty of movement for each part on the area based on the road surface database, The control device changes the relationship between the score information in the road surface database and the difficulty of movement in the cost map based on the conditions. The mobile body moves with driving assistance based on the cost map. A mobile object.

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