Vehicle system

Abstract

To provide a system that uses a magnetic marker to enable a vehicle to travel automatically, and that can precisely control a vehicle after the vehicle moves from a position outside a route where the magnetic marker is placed until the magnetic marker is detected.SOLUTION: In a vehicle system 1 which causes a vehicle 2 to travel through a movement space 1A having a route 100 with magnetic markers 10 arranged at intervals, the vehicle 2 is controlled using a vehicle position estimated by UWB positioning when the vehicle 2 moves from a position in the movement space 1A that is off the route 100.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for automatically driving a vehicle using a magnetic marker. [Background technology]

[0002] Conventionally, automated guided vehicles have been widely used in factories, logistics warehouses, etc. As a system for automatically driving automated guided vehicles, a system using magnetic markers placed at intervals along a route has been proposed (see, for example, Patent Document 1). In this system, steering control is performed using the lateral deviation of the vehicle relative to the magnetic markers as a control amount, thereby moving the vehicle along the route. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-158109 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional system, when the vehicle starts at a location off the route, such as a waiting area, a challenge is ensuring controllability of the vehicle until it first detects a magnetic marker on the route.

[0005] The present invention has been made in consideration of the above-mentioned problems of the conventional art, and aims to provide a system that uses magnetic markers to automatically drive a vehicle, which can precisely control the vehicle from the time the vehicle moves from a position outside the route where the magnetic markers are placed until the magnetic markers are detected. [Means for solving the problem]

[0006] The present invention provides a vehicle system for a vehicle traveling in a moving space having a path on which magnetic markers are arranged at intervals, the system comprising: a magnetic detection circuit provided in the vehicle for detecting the magnetic marker; a driving control circuit that controls the driving of the vehicle; a plurality of fixed stations arranged to wirelessly communicate with vehicles in a moving space; at least one in-vehicle communication circuit provided in a vehicle for wireless communication with the plurality of fixed stations; a distance measuring circuit that measures a distance between any one of the plurality of fixed stations and the at least one vehicle-mounted communication circuit through wireless communication between the any one of the fixed stations and the at least one vehicle-mounted communication circuit; a positioning circuit that estimates a position of the at least one vehicle-mounted communication circuit in the moving space based on a distance between the at least one vehicle-mounted communication circuit and at least two or more fixed stations among the plurality of fixed stations, and estimates a position of the vehicle based on the position of the at least one vehicle-mounted communication circuit; When the vehicle moves from a position outside the route in the travel space, the travel control circuit controls the vehicle to move to a position where any of the magnetic markers is installed, using the vehicle position estimated by the positioning circuit; After any of the magnetic markers is detected, the vehicle system is configured to control the vehicle to move along the route while detecting magnetic markers placed along the route. [Effects of the Invention]

[0007] The vehicle system of the present invention is a system in which a vehicle moves along a route while detecting magnetic markers. The vehicle in this vehicle system is equipped with a magnetic detection circuit for detecting the magnetic markers and an on-board communication circuit for wireless communication with a fixed station. In the vehicle system of the present invention, the position of the vehicle in a moving space is estimated by measuring the distance through wireless communication between the fixed station and the on-board communication circuit.

[0008] When the vehicle moves from a position off the route, the driving control circuit that controls the vehicle's driving uses the distance measured by wireless communication to estimate the vehicle's position and guides the vehicle to the location of one of the magnetic markers. After one of the magnetic markers is detected, the driving control circuit controls the vehicle to move while detecting the magnetic markers placed along the route.

[0009] According to the vehicle system of the present invention, even if the vehicle moves from a position outside the route on which the magnetic markers are arranged, the vehicle can be controlled with high precision until one of the magnetic markers is detected. After one of the magnetic markers is detected, the vehicle can be controlled with high precision using the magnetic markers. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram of a vehicle system according to a first embodiment. [Figure 2] FIG. 1 is a configuration diagram of a vehicle in a first embodiment. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the vehicle in the first embodiment. [Figure 4] FIG. 2 is a block diagram showing a magnetic sensor module according to the first embodiment. [Figure 5] FIG. 4 is an explanatory diagram of how the distance between the fixed station and the communication circuit is projected onto a two-dimensional plane in the first embodiment. [Figure 6] FIG. 1 is a diagram illustrating UWB positioning according to the first embodiment. [Figure 7] FIG. 2 is a second explanatory diagram of UWB positioning in the first embodiment. [Figure 8] FIG. 10 is an explanatory diagram of UWB positioning in the second embodiment. [Figure 9] FIG. 11 is an explanatory diagram of coordinate definitions in the third embodiment. [Figure 10] FIG. 10 is an explanatory diagram of UWB positioning in the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The moving space in the present invention may be an indoor moving space in a facility such as a factory or warehouse, or an outdoor moving space such as an airport or port. It may also be a moving space that is both indoors and outdoors. The vehicle may be a work vehicle or a dedicated vehicle such as a bus, and the moving space may be a moving space with a dedicated road for buses and the like to travel on. Furthermore, the vehicle may include a general vehicle, and the moving space may be a moving space including a road on which general roads can be traveled.

[0012] The embodiments of the present invention will be specifically described using the following examples. Example 1 This example relates to a vehicle system for a vehicle 2 traveling in a moving space 1A having a route 100 on which magnetic markers 10 are arranged at intervals. The details of this system will be described with reference to Figs. 1 to 7.

[0013] The vehicle system 1 (FIG. 1) of this example is an example of a vehicle system capable of performing steering control for driving a vehicle 2 along a route 100. The vehicle system 1 is configured by combining an autonomously driving vehicle 2 and two fixed stations 5a and 5b that communicate wirelessly with the vehicle 2. The vehicle 2 is, for example, 2 m long and 1 m wide.

[0014] The vehicle system 1 targets a movement space 1A for a vehicle 2 that is provided indoors, such as in a factory or a logistics warehouse. This movement space 1A is provided with a route 100 along which the vehicle 2 travels, a parking space 102 where the vehicle 2 waits, and the like. The vehicle 2 travels along the route 100 to perform work such as transporting goods, and when the work is completed, moves to the parking space 102 and waits. The parking space 102 is located off the route 100 so that the waiting vehicle 2 does not interfere with the vehicle 2 traveling along the route 100.

[0015] Magnetic markers 10 are placed at intervals along the route 100. The intervals between the magnetic markers 10 are, for example, 2 m. As shown in Figure 3, the magnetic markers 10 are sheet-shaped permanent magnets with a diameter of 100 mm and a thickness of 2 mm. Note that instead of the sheet-shaped magnetic markers 10, columnar magnetic markers may also be used.

[0016] The parking space 102 is a space for parking the vehicle 2 waiting for work. As described above, the parking space 102 is located off the route 100. There are no magnetic markers 10 between the parking space 102 and the route 100. When the vehicle 2 parked in the parking space 102 starts work, it needs to autonomously travel to merge onto the route 100. In the vehicular system 1, information on which side the parking space 102 is located with respect to the line connecting the fixed stations 5A and 5B is stored in advance by the vehicle 2. This information is an example of information regarding the location of the vehicle 2 in the moving space 1A.

[0017] The fixed stations 5a and 5b are wireless communication devices that perform wireless communication with the vehicle 2. In the vehicle system 1A, the absolute positions of the fixed stations 5a and 5b in the moving space 1A are known. The absolute positions of the fixed stations 5a and 5b serve as reference positions when estimating the vehicle position. Position information of the fixed stations 5a and 5b is stored on the vehicle 2 side. The position information also includes altitude information of the fixed stations 5a and 5b.

[0018] In the configuration of this example, fixed stations 5a and 5b are placed at two locations on both sides of the moving space 1A. The fixed stations 5a and 5b each emit their own unique radio waves. In this example, ultra-wideband wireless communication (UWB) is used as the wireless communication method between the fixed station 5 and the vehicle 2. However, the wireless communication method is not limited to UWB. For example, other wireless communication methods such as BLE (Bluetooth Low Energy) and WiFi (Wireless Fidelity) can also be used.

[0019] As shown in Fig. 2, the vehicle 2 is a four-wheel vehicle equipped with a pair of left and right front wheels 211 that are steered wheels and a pair of left and right rear wheels 212 that are drive wheels. The size of the vehicle 2 is 2 m in length and 1 m in width. A rod-shaped magnetic sensor unit 3 is attached to the rear end of the vehicle 2 so as to extend along the vehicle width direction (lateral direction).

[0020] 3, the vehicle 2 is configured around a control unit 20 that executes vehicle control. The control unit 20 is an example of a driving control circuit that controls the driving of the vehicle 2. The control unit 20 is electrically connected to a magnetic sensor unit 3 that performs magnetic detection, a motor unit 24 that rotates and drives the rear wheels 212, a wheel speed unit 242 that measures the wheel speed, a steering unit 26 that steers the front wheels 211 that are steered wheels, a communication circuit 23 that is an example of an on-vehicle communication circuit, and the like.

[0021] The communication circuit 23 is mounted in a predetermined mounting position at the front of the vehicle 2. The relative positional relationship between the mounting position of the communication circuit 23 and a reference position (reference position) of the vehicle 2 is known. Information representing this positional relationship is stored in advance on the vehicle 2 side. The reference position of the vehicle 2 is a position on the vehicle 2 that is to be measured or controlled as the vehicle position. The height of the reference position is set to the same height as the communication circuit 23.

[0022] The control unit 20 of the vehicle 2 is configured using a CPU that performs various calculations, memory elements such as ROM and RAM, etc. The control unit 20 is equipped with an I / O circuit that performs communication with external units. The control unit 20 performs communication with external units such as the magnetic sensor unit 3 and the communication circuit 23 via the I / O circuit.

[0023] The magnetic sensor unit 3 (FIG. 4) is an example of a magnetic detection circuit for detecting the magnetic marker 10. It includes 15 magnetic sensors Cn (n is an integer between 1 and 15) arranged in a straight line, and a detection processing circuit 32 incorporating a CPU and the like (not shown). In the rod-shaped magnetic sensor unit 3, the 15 magnetic sensors Cn are arranged at 5 cm intervals along its longitudinal direction. When the magnetic sensor unit 3 is attached to the vehicle 2 along the vehicle width direction, the 15 magnetic sensors Cn are arranged in a straight line along the vehicle width direction.

[0024] The magnetic sensor Cn is a sensor that detects magnetism by utilizing the well-known MI effect (Magnet Impedance Effect). The MI effect is a magnetic effect in which the impedance of a magnetically sensitive body such as amorphous wire changes sensitively in response to an external magnetic field. In the magnetic sensor Cn, the amorphous wire, which is the magnetically sensitive body, is linearly incorporated. The magnetic sensor Cn outputs an output signal that represents the magnitude of the magnetism acting in the longitudinal direction of the magnetically sensitive body. In the magnetic sensor unit 3 of this example, each magnetic sensor Cn is incorporated so that the magnetically sensitive body (not shown) is aligned vertically.

[0025] The detection processing circuit 32 (FIG. 4) of the magnetic sensor unit 3 is an arithmetic circuit that executes marker detection processing to detect the magnetic marker 10. Although not shown, the detection processing circuit 32 is configured using a CPU that executes various calculations, memory elements such as ROM and RAM, etc.

[0026] The detection processing circuit 32 acquires the output signal of each magnetic sensor Cn at a frequency of 3 kHz and executes marker detection processing. In the marker detection processing, in addition to detecting the magnetic marker 10, the deviation of the vehicle 2 in the vehicle width direction (called lateral deviation) from the magnetic marker 10 is measured. The detection processing circuit 32 inputs the detection results of the marker detection processing to the control unit 20. The detection results include whether or not the magnetic marker 10 has been detected, as well as the lateral deviation from the magnetic marker 10.

[0027] The control unit 20 (see FIG. 3) of the vehicle 2 realizes various functions by the execution of software programs by the CPU. The functions realized by the control unit 20 include, for example, the functions of the following circuits. (1) Driving control circuit: A circuit that executes vehicle control, including steering control. (2) Distance measurement circuit: A circuit that measures the distance between the fixed station 5 and the communication circuit 23 of the vehicle 2 through wireless communication between the fixed station 5 and the communication circuit 23. The distance measurement circuit measures the distance between each of the two fixed stations 5a and 5b. (3) Positioning circuit: A positioning circuit that estimates the vehicle position (the position of vehicle 2). The positioning circuit estimates the position of the communication circuit 23 in the moving space 1A by using the distance between the communication circuit 23 of vehicle 2 and the two fixed stations A and B5. Then, the vehicle position is estimated based on the position of the communication circuit 23. In the following explanation, such positioning by the positioning circuit is referred to as UWB positioning.

[0028] The control of the vehicle 2 in the vehicle system 1 configured as above will now be described. The control of the vehicle 2 can be broadly categorized into (1) control of traveling along the route 100 and (2) control of traveling outside the route 100. (1) Control of traveling along the route 100 is control for traveling along the route 100 while detecting the magnetic markers 10. (2) Control of traveling outside the route 100 is control from, for example, starting to move from a parking space 102 to joining the route 100.

[0029] (1) Travel control along route 100 As described above, the magnetic markers 10 are placed at intervals along the route 100. While the vehicle 2 is traveling along the route 100, the magnetic markers 10 are repeatedly detected. When the magnetic markers 10 are detected, the lateral deviation of the vehicle 2 relative to the magnetic markers 10 is measured. The control unit 20 steers the front wheels 211, which are steerable wheels, so as to bring the lateral deviation of the vehicle 2 relative to the magnetic markers 10 closer to zero. This allows the vehicle 2 to travel along the route 100 while slightly meandering.

[0030] (2) Driving control outside route 100 In the vehicle system 1 of this example, a parking space 102 where a vehicle 2 waiting for work waits is located off the route 100. The vehicle 2 needs to move between the route 100 and the parking space 102 without relying on the magnetic marker 10. For example, when the vehicle 2 waiting in the parking space 102 resumes work, the vehicle 2 needs to merge with the route 100 in accordance with a work instruction and move to the destination. Once the vehicle 2 merges with the route 100, the above-described vehicle control allows the vehicle 2 to travel along the route 100 using the magnetic marker 10. On the other hand, after starting to move from the parking space 102 located off the route 100, the vehicle 2 needs to move without using the magnetic marker 10 until it merges with the route 100.

[0031] When starting to move from the parking space 102, the vehicle 2 first estimates its position by performing positioning processing (UWB positioning) based on wireless communication with the fixed stations 5a and 5b. The control unit 2 determines, by calculation, the driving route for merging with the route 100, using the vehicle's position at the start of movement as the starting position. The control unit 2 controls the vehicle 2 so that it can move along the set driving route while repeatedly performing UWB positioning to estimate the vehicle's position.

[0032] Next, we will explain the details of UWB positioning using the fixed stations 5a and 5b. UWB positioning is based on measuring the distance between the fixed stations 5a and 5b and the communication circuit 23 installed in the vehicle 2. In response to wireless communication between the communication circuit 23 and each fixed station 5, the control unit 20 measures the distance da' between the communication circuit 23 and the fixed station 5a and the distance db' between the communication circuit 23 and the fixed station 5b.

[0033] Methods for measuring the distance between the fixed stations 5a and 5b and the communication circuit 23 include, for example, propagation delay measurement (ToF: Time of Flight) or RSSI (Received Signal Strength Indicator). The method for measuring distance is not particularly limited, and various methods for measuring distance can be adopted.

[0034] As described above, the vehicle 2 stores position information including the height of the fixed station 5. As shown in FIG. 5, the control unit 20 obtains the distances da and db on a two-dimensional plane P1, which is the horizontal plane to which the on-board communication circuit 23 belongs, by projecting the distances da' and db' from the fixed station 5 onto this two-dimensional plane P1. The distances da and db can be calculated based on the distances da' and db' using Pythagoras' theorem. The two-dimensional plane P1 is a horizontal plane parallel to the road surface Rs.

[0035] If the distances (projection distances) da and db between the communication circuit 23 and the fixed stations 5a and 5b, whose absolute positions in the mobile space 1A are known, can be determined, then the candidate positions of the communication circuit 23 can be limited to two locations on the two-dimensional plane by graphical processing, as shown in Figure 6. The two candidate locations are located on both sides of the line L1 connecting the fixed stations 5a and 5b.

[0036] In the vehicle system 1, information regarding which side of the line L1 connecting the fixed station 5a and the fixed station 5b in the moving space 1A the parking space 102 is located on is known in advance. This information is an example of information regarding the location of the vehicle 2 in the moving space 1A. By using this information, one of the two candidate locations can be selected as the location of the communication circuit 23. If the location of the communication circuit 23 in the moving space can be estimated in this way, the vehicle location can be estimated based on the location of the communication circuit 23.

[0037] As described above, the vehicle system 1 of this example is a system that targets an indoor travel space 1A that includes a route 100 on which magnetic markers 10 are laid, and a parking space 102 located off the route 100. This vehicle system 1 executes travel control using the magnetic markers 10 and travel control based on the vehicle position determined by wireless communication with fixed stations 5a and 5b.

[0038] In the vehicle system 1, when the vehicle 2 in the parking space 102 starts, the vehicle 2 merges with the route 100 while repeatedly estimating the vehicle's position (UWB positioning) through wireless communication with the fixed stations 5a and 5b. According to this vehicle system 1, when the vehicle 2 waiting in the parking space 102 resumes work, it can move with high accuracy to merge with the route 100.

[0039] Generally, in a vehicle system 1 using a magnetic marker 10, for example, when a vehicle 2 starts with its main power off, the magnetic marker 10 cannot be used until the vehicle joins the route 100, which tends to make vehicle control more difficult. By combining UWB positioning as in this example, the vehicle 2 can move with high precision even when the magnetic marker 10 is not detected, and can join the route 100 with high reliability. The vehicle system 1 of this example is particularly effective in indoor environments where it is difficult to determine the vehicle's position using, for example, a Global Navigation Satellite System (GNSS).

[0040] The vehicle system 1 of this example is effective in outdoor environments and in environments spanning indoor and outdoor environments. The vehicle system 1 of this example is particularly effective in outdoor environments where the reception of GNSS satellite radio waves is unstable. Even in environments where satellite radio waves can be received, the number of satellites from which satellite radio waves can be received may decrease depending on the time of day, resulting in a decrease in positioning accuracy. In contrast, the vehicle system 1 of this example, which estimates the vehicle position using UWB positioning or the like, reduces the risk of the vehicle position estimation accuracy fluctuating depending on the time of day.

[0041] As shown in Figure 7, after performing UWB positioning, it is also possible to drive vehicle 2 straight for a specified distance D and then perform UWB positioning again. When performing UWB positioning again, two locations are identified as candidates for the vehicle's position, as in the case of Figure 6. As described above, when performing UWB positioning previously, knowledge about the location of parking space 102 can be used to select one of the two candidate locations. When performing UWB positioning again, it is preferable to select the candidate of the two candidate locations whose distance from the vehicle's position estimated by the previous UWB positioning is closest to the specified distance.

[0042] It is also possible to assume that the vehicle 2 travels a straight line while traveling the specified distance D (see FIG. 7). In this case, the direction connecting the start point and end point of the travel section of the specified distance D can be estimated as the yaw angle of the vehicle 2.

[0043] In this example, a configuration example in which two fixed stations 5a and 5b are provided has been described, but it is also possible to provide three or more fixed stations. By using three or more appropriately placed fixed stations 5, the vehicle position can be uniquely estimated by UWB positioning.

[0044] It is also possible to provide the vehicle 2 with an IMU (Inertial Measurement Unit) that realizes inertial navigation. If the vehicle 2 is equipped with an IMU, it is possible to estimate the relative position and vehicle direction of the vehicle 2. By using the IMU, (1) in driving control along the route 100, the controllability of the vehicle 2 between adjacent magnetic markers 10 can be improved. (2) Even in driving control outside the route 100, the accuracy of vehicle control can be improved by estimating the relative position of the vehicle 2 based on the position where it started moving.

[0045] Example 2 This example is based on the vehicle system of the first embodiment and is an example in which a plurality of communication circuits 23 are provided in a vehicle 2. The details of this example will be described with reference to FIG.

[0046] The vehicle 2 of this example (FIG. 8) is equipped with two communication circuits 23A and 23B (examples of in-vehicle communication circuits). The communication circuit 23A is located at the front of the vehicle 2, and the communication circuit 23B is located at the rear of the vehicle 2. The positions of the communication circuits 23A and 23B in the vehicle 2 are known. Position information of the communication circuits 23A and 23B in the vehicle 2 is digitized and stored in advance on the vehicle 2 side.

[0047] In the vehicle system 1 of this example, as shown in Fig. 8, for the communication circuit 23A, distances da1 and db1 to the fixed station 5a and fixed station 5b are measured. For the communication circuit 23B, distances da2 and db2 to the fixed station 5a and fixed station 5b are measured. If the positions of the communication circuits 23A and 23B in the vehicle 2 are estimated as described above, it is possible to estimate the yaw angle, which is the orientation of the vehicle 2 in the fore-and-aft direction, using the line connecting the fixed stations 5a and 5b as a reference. The other configurations and effects are the same as those of the first embodiment.

[0048] Example 3 This example is an example in which the method of estimating the vehicle position is changed based on the vehicle system of the first embodiment, and the details thereof will be described with reference to FIG.

[0049] As shown in FIG. 9, the vehicle 2 in this example is a vehicle having a pair of left and right drive wheels 250, 252. The left and right drive wheels 250, 252 can be controlled to rotate independently. By rotating the left and right drive wheels 250, 252 in the same manner, the vehicle 2 can move forward or backward. By creating a difference in the rotational speeds (Vr, Vl) of the left and right drive wheels 250, 252, the direction (yaw angle) of the vehicle 2 can be changed. Using the rotational speeds (Vr, Vl) of the left and right drive wheels 250, 252, the velocity Vk and yaw rate γk of the vehicle 2 can be expressed by Equation 1. Note that the subscripts k and k-1 represent time points. The time point of subscript k-1 described below is the time point immediately before the time point of subscript k.

[0050]

number

[0051] In this example, similar to the first embodiment, when the vehicle 2 restarts, the initial position of the vehicle 2 is estimated by UWB positioning, and after the initial position is estimated, the vehicle position is estimated using a state space model. When the state and input are expressed by Equation 2 and Equation 3 under the coordinate definitions shown in FIG. 9, the state equation can be expressed by Equation 4, and the observation equation can be expressed by Equation 5. In the figure, the target position to be estimated as the vehicle position is expressed as three-dimensional coordinates (xc, yc, zc), the three-dimensional coordinate position of the communication circuit 23 is expressed as (xi, yi, zi), and the three-dimensional coordinate position of the fixed station 5 is expressed as (xj, yj, zj). The distance measured by wireless communication is expressed as dij.

[0052]

number

number

number

number

[0053] By using the state space model, it is possible to reduce positioning errors caused by errors in distance measurement by wireless communication. According to the vehicle system 1 of this example, the vehicle position can be estimated with high accuracy even when noise is superimposed on the radio waves for wireless communication. The other configurations and effects are the same as those of the first embodiment.

[0054] Example 4 This example is based on the vehicle system of the first embodiment and is configured so that the positions of the fixed stations 5a and 5b can be estimated while the vehicle 2 is traveling along a route 100. This will be described with reference to FIG.

[0055] In this example, the positions of the fixed stations 5a and 5b are not known in advance, and the vehicle 2 is configured to estimate the positions of the fixed stations 5a and 5b. In this configuration, the positions of the fixed stations 5a and 5b are not specified, but the positions of at least two of the magnetic markers 10 arranged on the route 100, 10A and 10B, are known. The magnetic markers 10A and 10B are equipped with wireless tags that output position information of their installation positions. Note that magnetic markers other than the magnetic markers 10A and 10B are not shown in Figure 10.

[0056] The vehicle 2 in this example is equipped with a tag reader that acquires tag information (location information) from a wireless tag. Since the installation position of the magnetic marker 10 is utilized, a communication circuit for distance measurement is located at a position corresponding to the center of the magnetic sensor unit in the vehicle 2. When such an arrangement is adopted, the position of the communication circuit when the magnetic marker 10 is detected will approximately coincide with the installation position of the magnetic marker 10.

[0057] While traveling along route 100, vehicle 2 detects magnetic markers A and B. When magnetic marker 10A is detected, distance measurement is performed by wireless communication to determine distance daA between fixed station 5a and the communication circuit and distance dbA between fixed station 5b and the communication circuit. As described above, distances daA and dbA can be treated as the distance between fixed station 5a or 5b and magnetic marker 10A.

[0058] Furthermore, when a magnetic marker 10B is detected while traveling along the route 100, distance measurement is performed by wireless communication to determine the distance daB between the fixed station 5a and the communication circuit and the distance dbB between the fixed station 5b and the communication circuit. As with the detection of the magnetic marker 10A, the distances daB and dbB can be treated as the distance between the fixed station 5a or 5b and the magnetic marker 10B.

[0059] Using distances daA and daB, the absolute position of fixed station 5a in movement space 1A can be estimated based on the installed positions of magnetic markers 10A and 10B. Also, using distances dbA and dbB, the absolute position of fixed station 5b in movement space 1A can be estimated based on the installed positions of magnetic markers 10A and 10B.

[0060] In this way, in the vehicle system 1 of this example, a vehicle traveling along the route 100 can estimate the absolute positions of the fixed stations 5a and 5b. There is no need to know the absolute positions of the fixed stations 5a and 5b in advance. In other words, the vehicle system 1 can be easily constructed because it is sufficient to install the fixed stations 5a and 5b in appropriate positions in the moving space 1A. The other configurations and effects are the same as those of the first embodiment.

[0061] Although specific examples of the present invention have been described in detail as examples, these examples merely disclose examples of the technology encompassed by the claims. Needless to say, the scope of the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that are obtained by variously modifying, changing, or appropriately combining the specific examples using publicly known technology and the knowledge of those skilled in the art. [Explanation of symbols]

[0062] 1 Vehicle Systems 1A moving space 10, 10A, 10B magnetic markers 100 routes 102 parking spaces 2 vehicles 20 Control unit (driving control circuit) 23 Communication circuit (vehicle communication circuit) 3 Magnetic sensor unit (magnetic detection circuit) 211 Front wheels (steering wheels) 212 rear wheel 3 Magnetic sensor unit (magnetic measurement circuit) 5, 5A, 5B fixed station Cn (n is an integer between 1 and 15) Magnetic sensor P1 2D plane Rs road surface

Claims

1. A vehicle system for a vehicle traveling in a moving space having a path on which magnetic markers are arranged at intervals, a magnetic detection circuit provided in the vehicle for detecting the magnetic marker; a driving control circuit that controls the driving of the vehicle; a plurality of fixed stations arranged to wirelessly communicate with vehicles in a moving space; at least one in-vehicle communication circuit provided in a vehicle for wireless communication with the plurality of fixed stations; a distance measuring circuit that measures a distance between any one of the plurality of fixed stations and the at least one vehicle-mounted communication circuit through wireless communication between the any one of the fixed stations and the at least one vehicle-mounted communication circuit; a positioning circuit that estimates a position of the at least one vehicle-mounted communication circuit in the moving space based on a distance between the at least one vehicle-mounted communication circuit and at least two or more fixed stations among the plurality of fixed stations, and estimates a position of the vehicle based on the position of the at least one vehicle-mounted communication circuit; When the vehicle moves from a position outside the route in the travel space, the travel control circuit controls the vehicle to move to a position where any of the magnetic markers is installed, using the vehicle position estimated by the positioning circuit; After any of the magnetic markers is detected, the vehicle system is configured to control the vehicle to move along the route while detecting magnetic markers positioned along the route.

2. According to claim 1, the positioning circuit projects the distances between two fixed stations as the any two or more fixed stations and the at least one vehicle-mounted communication circuit onto a two-dimensional plane corresponding to the moving space, thereby identifying a plurality of candidate positions for the position of the at least one vehicle-mounted communication circuit on the one two-dimensional plane, and A vehicle system that estimates the position of the at least one on-board communication circuit by selecting one of the plurality of candidate positions using information regarding the position of the vehicle in the moving space.

3. 2. The method according to claim 1, wherein the at least one vehicle-mounted communication circuit is provided in the vehicle with at least two vehicle-mounted communication circuits mounted at different positions, The positioning circuit estimates the vehicle's direction using the positions of the two on-board communication circuits in the moving space.

4. 2. The positioning circuit according to claim 1, wherein when the vehicle moves from a position outside the route in the movement space, a first process for estimating a position of a vehicle based on a position of the at least one in-vehicle communication circuit estimated based on a distance between the at least one in-vehicle communication circuit and any two or more fixed stations; A vehicle system configured to execute a second process for estimating the position of the vehicle using a state space model until the vehicle reaches the location where any of the magnetic markers is installed.

5. 5. The vehicle system according to claim 1, wherein the fixed station and the in-vehicle communication circuit are configured to perform wireless communication using ultra-wideband wireless communication technology.

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