JP2016065769A - Transport vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transport vehicle capable of further improving correction accuracy for correcting a vehicle position detected by a global coordinate system in response to a vehicle body attitude.SOLUTION: A transport vehicle comprises: a vehicle body frame 40; a deck 90 disposed in an upper portion in front of the vehicle body frame 40; and a driving room mounted on the deck 90. The transport vehicle also comprises: two antennas 101 and 102 receiving positioning satellite radio waves (GPS); and a vehicle-body-attitude detector 200 (inertia measuring unit: IMU). The two GPS antennas 101 and 102 are attached to the deck 90 to be spaced apart from each other in the width direction of the transport vehicle. The vehicle-body-attitude detector 200 is located within a rectangular region 400 having, as a diagonal, a line segment DL that joins installation positions of the two GPS antennas 101 and 102 to each other or within a range in which the deck 90 can be attached.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a position measurement technique for a transport vehicle.

  As a technique for correcting an error in a vehicle position detected by a global positioning system (GPS), Patent Document 1 includes “position detection means for detecting a vehicle position by GPS and position information from an optical beacon. In-vehicle communication means for receiving optical beacon data, imaging means for starting imaging above the vehicle when the optical beacon data is received, extraction means for extracting an optical beacon head image from the captured image, and the vehicle is located directly below the optical beacon A position that the optical beacon head image occupies in the image is set as a reference position in advance, and a right-down determination unit that determines whether or not the extracted optical beacon head image is positioned at the reference position; and an optical beacon head When the image is located at the reference position, the vehicle position at the time when the optical beacon head image is captured is And a position correcting means for correcting the vehicle position so as to coincide with the position indicated by the data ”.

JP 2010-276583 A

  A transport vehicle traveling in a mine changes the body posture of the transport vehicle depending on the loaded state and unloaded state (empty state) of the load. Therefore, an error due to a change in the body posture may be included in the vehicle position calculated by GPS. is there. Therefore, an inertial measurement device (IMU: Internal Measurement Unit) is mounted on the transport vehicle, and the vehicle position detected by the GPS is corrected using the vehicle body posture information detected by the IMU. If the detection accuracy of the vehicle body posture information is low, there is a concern that the accuracy of the corrected vehicle position also decreases.

  In this regard, Patent Document 1 discloses a configuration that corrects the positional deviation between the vehicle position calculated by the GPS and the global coordinates, but does not consider the error included in the vehicle body posture information detected by the IMU. However, when GPS and IMU are used together, there remains a problem that the correction accuracy is reduced due to an error included in the vehicle body posture information.

  The present invention has been made in order to solve the above-described problem, and provides a transport vehicle capable of further improving the correction accuracy when correcting the vehicle position detected in the global coordinate system according to the vehicle body posture. The purpose is to provide.

  The present invention for solving the above-mentioned problems is a transport vehicle comprising a vehicle body frame, a deck disposed at an upper front portion of the vehicle body frame, and a cab mounted on the deck. A positioning satellite radio wave reception antenna and a vehicle body attitude detection device for detecting the attitude of the transport vehicle, wherein the two positioning satellite radio wave reception antennas are spaced apart from each other in the width direction of the transport vehicle, respectively. The vehicle body posture detection device is located in a rectangular area having a line segment connecting the installation positions of the two positioning satellite radio wave receiving antennas as a diagonal line or an attachable range of the deck in a top view of the transport vehicle. It is characterized by.

  According to the present invention, it is possible to provide a transport vehicle that can further improve the correction accuracy when performing correction according to the vehicle body posture with respect to the vehicle position detected in the global coordinate system. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is an overall configuration diagram of a dump vehicle according to an embodiment of the present invention. The block diagram which shows the function structure of the dump dump concerning one embodiment of the present invention. It is a top view of dumping, (a) shows the state where IMU was installed in the overlap area of the rectangular area and deck which set the installation position of two GPS antennas as a diagonal line, (b) is further on a diagonal line Indicates the installed state. FIG. 6A is a top view of a dump, in which (a) shows a y-axis passing through the center of a distance Δx between two rectangular antennas within an overlapping area between a rectangular area and a deck whose diagonals are two GPS antenna installation positions; (B) shows a state where the IMU is installed on the deck when there is no overlapping area between the rectangular area and the deck. It is a top view of a dump truck, and shows a state in which an IMU is installed on a deck when a rectangular area whose diagonal is the installation position of two GPS antennas cannot be formed.

  In the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. In the following embodiments, when referring to the number of elements, etc. (including the number, numerical value, quantity, range, etc.), unless otherwise specified and in principle limited to a specific number in principle, It is not limited to the specific number, and may be more or less than the specific number. In the following embodiments, the constituent elements (including processing steps and the like) are not necessarily essential unless explicitly stated or considered to be clearly essential in principle.

  In addition, each of the configurations, functions, processing units, processing units, and the like in the following embodiments may be realized in part or in whole as, for example, an integrated circuit or other hardware. In addition, each configuration, function, processing unit, processing unit, and the like, which will be described later, may be realized as a program executed on a computer. That is, it may be realized as software. Information such as programs, tables, files, etc. for realizing each configuration, function, processing unit, processing means, etc. is stored in memory, hard disk, storage device such as SSD (Solid State Drive), storage medium such as IC card, SD card, DVD, etc. Can be stored.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same or related reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof is omitted. In the following embodiments, the description of the same or similar parts will not be repeated in principle unless particularly necessary.

  Hereinafter, a configuration of a dump truck in which the present invention is applied to a transport vehicle (a dump truck, hereinafter abbreviated as “dump truck”) that autonomously travels without being operated by an operator in the mine will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall configuration diagram of a dump truck according to an embodiment of the present invention. FIG. 2 is a block diagram showing a functional configuration of a dump according to an embodiment of the present invention.

  In describing the configuration of the dump 1 in FIG. 1, a coordinate system used in the present embodiment will be described. The coordinate system includes a vehicle body coordinate system of the dump 1 and a local coordinate system. The vehicle body coordinate system includes an x-axis parallel to a rear wheel axis (vehicle width direction), which will be described later, a y-axis parallel to the front-rear axis (longitudinal direction) of the vehicle body frame 40, and the z-axis upward in the vertical direction. An axis is set. The origin of the vehicle body coordinate system can be arbitrarily set within the range of the overall length, width, and height of the vehicle. The local coordinate system is a coordinate system for managing the position of the vehicle, and the E axis is set to the true east, the N axis is set to the true north, and the U axis is set to the upper direction with a certain position on the earth as the origin. Note that the local coordinate system is a relative coordinate having a certain position on the earth as the origin in the global coordinate system that is an absolute coordinate on the earth, and is therefore included in the global coordinate system.

  The dump truck 1 shown in FIG. 1 includes a vehicle body frame 40, a front wheel 10 that is a driven wheel attached to a lower front portion of the vehicle body frame 40, a rear wheel 20 that is a drive wheel attached to a lower rear portion, and a vehicle body frame 40. A loading platform 30 that is rotatably supported via a support shaft 60 and a hoist cylinder 50 that rotates the loading platform 30 about the support shaft 60 by expanding and contracting are provided. When the hoist cylinder 50 is extended, the loading platform 30 operates so as to raise the front end while rotating about the support shaft 60 to increase the inclination angle, and the loading 35 loaded on the loading platform 30 becomes the loading platform 30. It is discharged from the rear end.

  The rear wheels 20 are arranged on both the left and right sides so that the two tires have a wider width, and the rear wheel tire width is approximately twice that of the front wheels (see FIG. 3). The vehicle body frame 40 is mounted with a travel drive device 350 (see FIG. 2) including a brake, a steering, an engine, and the like. When the driving force is transmitted from the traveling drive device 350 to the rear wheel 20, the dump wheel 20 travels on the road surface by the front wheel 10 and the rear wheel 20.

  A front portion 70 of the vehicle body frame 40 includes a building 70 that houses a radiator (not shown), and a deck 90 that is installed on the upper portion and supports the driver's seat 80.

  In front of the dump 1, as a configuration for detecting the vehicle position in the global coordinate system, two GPS antennas (corresponding to positioning satellite radio wave receiving antennas) 101 and 102, and GPS received by the GPS antennas 101 and 102 are provided. Vehicle position detection device 103 that detects the vehicle position of the global coordinate system of dump 1 based on satellite information, vehicle body posture calculation device 200 that calculates the vehicle body posture of the host vehicle, and in-vehicle terminal device that performs autonomous travel control of dump 1 300.

  In this embodiment, GPS is used as a global coordinate system vehicle position detection device. However, the vehicle position calculation device is not limited to GPS, and positioning satellite radio waves are generated from navigation satellites that constitute a global navigation satellite system (GNSS). May be used as long as the position of the host vehicle is acquired, and GLONASS (Global Navigation Satellite System) or GALILEO may be used.

  Further, in the present embodiment, an IMU is used as the vehicle body posture calculation device 200, and hence is referred to as an IMU 200 below.

  Although FIG. 1 illustrates a state where the vehicle position detection device 103 and the IMU 200 are installed on the upper surface of the deck 90, the installation positions of the deck 90, the IMU 200 and the vehicle position detection device 103 are limited to the case where they are installed on the upper surface of the deck 90. Instead, it may be installed on the lower surface of the deck 90. The arrangement position of the in-vehicle terminal device 300 is only an example, and is not limited to FIG.

  The front wheel 10 is provided with a wheel speed sensor 210 that measures the speed in the direction in which the wheel faces depending on the number of rotations of the wheel. The wheel speed sensor 210 may be attached to the rear wheel 20 or may be attached to both the front wheel 10 and the rear wheel 20.

  The vehicle body frame 40 is also equipped with a steering angle sensor 220 (see FIG. 2) for detecting the steering angle (tilt of the front wheels relative to the vehicle body axis) and a travel control device 350. I

  The vehicle position detection device 103 detects the position (GPS reference position) of the main GPS antenna 101 based on GPS satellite information obtained from the GPS antennas 101 and 102. Further, a vector from the GPS antenna 101 to 102 is detected.

As shown in FIG. 2, the IMU 200 includes an acceleration sensor 201, a gyro sensor 202, and a vehicle body posture calculation unit 203. The acceleration sensor 201 detects acceleration with respect to at least two axes of the x-axis and y-axis of the vehicle body coordinate system, and the gyro sensor detects an angular velocity around at least the z-axis of the vehicle body coordinate system.
The vehicle body posture calculation unit 203 includes the acceleration including the direction of gravity applied to the vehicle body, the result of measuring the rotational angular velocity of the vehicle body frame 40, the vehicle body velocity in the vehicle movement direction measured by the wheel speed sensor 210, and the steering angle sensor 220. Is used to calculate the pitch angle, roll angle, and yaw angle (collectively referred to as the attitude angle) of the dump truck 1 as the vehicle body posture information of the vehicle body frame 40. Here, the pitch angle is an angle formed by the x axis with the local coordinate system EN plane, the roll angle is a rotation angle around the x axis, and the yaw angle is an angle formed by the x axis with the local coordinate system E axis. is there.

  The in-vehicle terminal device 300 corrects the GPS reference position acquired from the vehicle position detection device 103 using the attitude angle acquired from the IMU 200 and also stores positional deviation information between the GPS reference position stored in advance and the vehicle origin of the dump 1. Based on the vehicle position correction unit 301 that corrects the vehicle position used for the autonomous traveling control of the dump 1 and the operation management server (not shown) that manages the operation of the dump 1, the travel given to the dump 1 A wireless communication control unit 302 that transmits and receives a request and response for travel permission section information indicating a permitted section, a map information storage unit 303 that stores map information indicating a route on which the dump 1 travels autonomously, and a route in the travel permitted section Autonomous traveling that outputs a control signal for traveling along the vehicle position to the traveling drive device 350, such as a steering angle signal, a brake actuation signal, and a fuel injection signal It includes a control unit 304, a.

  The dump truck 10 for mine has a particularly large loading capacity, and a heavy weight is put on the body frame 40 in a loaded state. Therefore, the body frame 40 is not necessarily handled as a rigid body, and in particular, the frame is twisted and undulated on the y-axis of the body frame 40. Further, since the vehicle body frame 40 is connected to the front wheels 10 and the rear wheels 20 via dampers, vibration of the vehicle body frame 40 itself is generated separately from the vehicle motion. Depending on the mounting position of the IMU 200, due to these effects, the measured acceleration / angular velocity includes an error factor other than the vehicle motion, for example, the effects of vibration, swell, and torsion.

  Therefore, when the vehicle position correction unit 301 corrects the vehicle position using the attitude angle including an error factor other than the vehicle motion, the corrected vehicle position is deviated from the actual position of the local coordinate system of the dump truck 1. Thus, the accuracy of position control in autonomous traveling control is reduced.

  Therefore, in order to reduce the fact that the error angle is included in the attitude angle of the IMU 200, a rectangular area or deck 90 having a line segment connecting the installation positions of the two GPS antennas 101 and 102 as a diagonal line when the dump 1 is viewed from above. A configuration in which the IMU 200 is positioned within the attachable range will be described with reference to FIGS. 3 to 5. The above-mentioned “within the mountable range of the deck 90 includes not only directly provided on the deck but also provided via a support (post) or a handrail.” FIG. 3 is a top view of the dump truck. (A) shows the state where the IMU is installed in the overlapping area between the rectangular area and the deck where the installation positions of the two GPS antennas are diagonal lines, and (b) shows the state where they are further installed on the diagonal line. FIG. 4 is a top view of the dump, in which (a) shows the center of the distance Δx between the two GPS antennas in the overlapping area between the rectangular area and the deck whose diagonal is the installation position of the two GPS antennas. The state where the IMU is installed on the passing y-axis (front-rear axis) is shown, and (b) shows the state where the IMU is installed on the deck when there is no overlapping area between the rectangular area and the deck. FIG. 5 is a top view of the dump truck and shows a state in which an IMU is installed on the deck when a rectangular area whose diagonal line is the installation position of the two GPS antennas cannot be formed.

  3 (a), 3 (b), and 4 (a), the GPS antennas 101 and 102 protrude from the front of the dump 1 and from the body frame 40 of the dump 1 to the deck 90 when the dump 1 is viewed from above. It is attached. The GPS antennas 101 and 102 are attached with a distance Δx in the x-axis direction and a distance Δy in the y-axis direction. In FIG. 3, two points of the attachment positions of the GPS antennas 101 and 102 are represented by DL as a line segment, and a rectangular region having the diagonal line as a line is represented by reference numeral 400.

Errors due to undulation and torsion included in the attitude angle are considered to be a pitch angle error and a roll angle error, respectively, when modeled simply. Further, when viewed from the vicinity of the main GPS antenna 101, the undulation and torsion errors can be handled as waves having a certain amplitude, and can be expressed as follows.
Swell error [deg] = swell amplitude × sin (distance / period from GPS antenna)
Twist error [deg] = torsion amplitude × sin (distance / period from GPS antenna)

  Since the swell and twist cycles are considered to be sufficiently longer than the dump vehicle body length, the longer the distance from the GPS antenna 101, the greater the error. Therefore, the IMU 200 is arranged so that the distance from the GPS antenna 101 to the IMU 200 is shortened. As a guideline of the arrangement at this time, a distance that is considered to have little swell and twist error. This can be rephrased as a length (allowable error distance) that is considered to have little torsional or undulating error.

  For example, as shown in FIGS. 3 (a), 3 (b), and 4 (a), if another GPS antenna 102 is installed with a shift of the depth of the deck 90 (Δy), the difference between the GPS antennas can be reduced. The slope can be approximated. The inclination with respect to the local coordinate system EN plane to the GPS antenna 101 and the other GPS antenna 102 is calculated from a vector output by the vehicle position detection device 103. If the IMU 200 exists between them, the GPS is received from the IMU 200 at the timing of receiving the GPS. The obtained inclination including the error can be corrected. By this processing, errors due to waviness and torsion appearing on the moving body frame 40 approach a static state, and the influence on position correction (conversion between the local coordinate system and the vehicle body coordinate system) is reduced. Can do. Similarly, the same effect can be obtained by shifting the body frame 40 in the width direction by shifting the width of the cab deck (Δx).

  3A, 3B and 4A, a plane surrounded by a plurality of GPS antennas 101 and 102 (a plane including the rectangular region 400) is assumed, and it is assumed that there is no distortion in the plane. Then, the calculation is performed assuming that the IMU 200 exists on the plane. Therefore, the IMU 200 may be arranged on the plane. More specifically, as shown in FIG. 3A, the IMU 200 is arranged in an overlapping area between the rectangular area 400 and the deck 90. Thereby, the influence of the wave | undulation and twist included in a posture angle can be reduced.

  In more detail, since this plane is a plane formed by the GPS antenna 100 and the GPS antenna 101, an error is included if the plane is separated from this axis. Ideally, it is more desirable that the IMU 200 exists on a line connecting the GPS antenna 100 and the GPS antenna 101 (see FIG. 3B). Thereby, IMU200 can be arrange | positioned on the diagonal line DL which is the shortest distance with GPS antenna 101,102, and the influence of a twist and a wave | undulation can be reduced rather than the case of (a) of FIG.

  Further, the posture detection error due to the vibration of the vehicle body frame 40 itself is caused by an error other than the undulation and torsion of the acceleration sensor 201 in the IMU 200. For example, the roll angular velocity generated around the x-axis of the body frame 40 is generated separately from the lateral acceleration calculated by the wheel speed sensor 210 and the steering angle sensor 220, and this is relatively larger than the output value of the acceleration sensor 201. Affect.

  Therefore, as shown in FIG. 4A, the IMU 200 is installed on the y-axis (shown as ax1) of the vehicle body frame 40 passing through the midpoint of Δx, thereby minimizing the influence of the angular velocity due to the roll angular motion of the vehicle body. Can be suppressed.

  Further, as shown in FIG. 4B, a support body 102 a protruding forward of the deck 90 is provided, the GPS antenna 102 is attached to the front end of the support body 102, and the GPS antenna 101 is attached to the y-axis of the deck 90. When the front end portion of the deck 90 on the opposite side of the GPS antenna 102 with the ax1 interposed is provided, there is no overlapping area between the rectangular area 400 and the deck 90, that is, the rectangular area 400 protrudes from the dump 1. In this case, the IMU 200 may be installed on the deck 90. Further, the deck 90 may be installed on the front-rear axis ax1. The installation positions of the GPS antennas 101 and 102 are such that the dump 1 does not interfere with the rotation range of the loading platform 30 and is restricted by the area of the deck 90 and the like. , 102 may have to be provided. In this case, by installing the IMU 200 on the deck 90, the GPS antennas 101 and 102 can be brought closer, and the detection error between the GPS satellite signal and the IMU can be further reduced.

  Further, as shown in FIG. 5, when the GPS antennas 101 and 102 are installed on the deck 90 without being spaced apart in the front-rear axis ax1 direction, the rectangular area 400 cannot be formed, and the rectangular area 400 overlaps with the deck 90. There is no. In this case, by installing the IMU 200 on the deck 90, the distance between the GPS antennas 101 and 102 and the IMU 200 can be made shorter than when the IMU 200 is installed outside the deck 90, and the influence of error factors on the posture angle can be reduced. .

  According to the present embodiment, posture detection error due to vibration of the vehicle body frame itself included in vehicle body posture information, posture detection error due to waviness error, posture detection error due to torsion can be reduced, and vehicle position detection accuracy is improved. Can be made.

  The above-described embodiment is an example for explaining the present invention, and is not intended to limit the scope of the present invention to the above-described embodiment. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

  As an example, the IMU mounting position examples shown in FIGS. 3 and 4 may be appropriately combined. For example, the IMU 200 may be installed on the diagonal line DL shown in FIG. 3B and the intersection of the y-axis ax1 shown in FIG. Thereby, IMU can be arrange | positioned in the position which reduces the vibration of a vehicle body frame, a wave | undulation, and a twist.

In FIGS. 3 and 4A, the GPS antennas 101 and 102 are attached at positions protruding from the deck 90, but may be attached on the deck 90. In this case, the area of the rectangular area 400 is smaller than the upper surface of the deck 90, but the IMU 200 is installed in the rectangular area 400 on the deck 90, that is, in the overlapping area of the deck 90 and the rectangular area 400. The same effect as described in the above can be obtained.

  In the present embodiment, the example in which the present invention is applied to a dump truck has been described. However, the present invention can also be applied to detection of a vehicle position such as a hydraulic excavator or a wheel loader that is a working machine other than the dump truck.

1: dump, 40: body frame, 90: deck, 101, 102: GPS antenna, 200: IMU, 400: rectangular area,

Claims (3)

A transport vehicle comprising a vehicle body frame, a deck disposed at an upper front portion of the vehicle body frame, and a cab mounted on the deck,
Two positioning satellite radio receiving antennas,
A vehicle body posture detection device for detecting the posture of the transport vehicle,
The two positioning satellite radio wave receiving antennas are attached to the deck, with an interval in the width direction of the transport vehicle,
The vehicle body posture detection device is located in a rectangular area having a line connecting the installation positions of the two positioning satellite radio wave reception antennas as diagonal lines or in an attachable range of the deck in a top view of the transport vehicle.
A transport vehicle characterized by that. The vehicle body posture detection device is disposed on the longitudinal axis of the vehicle body frame passing through the midpoint of the distance along the width direction of the two positioning satellite radio wave receiving antennas within the rectangular area or the mountable range of the deck. The
The transport vehicle according to claim 1. The two positioning satellite radio wave receiving antennas are respectively attached to the deck with an interval in the front-rear direction of the transport vehicle,
The vehicle body posture detection device is installed in the overlapping area when there is an overlapping area between the rectangular area and the deck, and is installed in the deck when there is no overlapping area.
The transport vehicle according to claim 1.