JP6947563B2 - Mobile robot control device and control method - Google Patents

Description

The present technology relates to a control device and a control method for controlling the movement of a mobile robot so as to avoid a collision with an obstacle.

When a mobile robot such as an unmanned vehicle is autonomously moved, the mobile robot is provided with an obstacle sensor and a control device. The obstacle sensor detects surrounding obstacles from the mobile robot. The control device controls the mobile robot so that the mobile robot moves along a movement path that avoids the detected obstacle. For example, a target position for movement and a plurality of waypoints to pass before reaching this target position are preset, and the control device moves to the next waypoint while avoiding detected obstacles. To generate.

The above-mentioned mobile robot may be configured as a semi-autonomous mobile robot so as to receive an abstract command from the operator. The semi-autonomous mobile robot generates a movement path by itself based on an abstract command. An abstract command is a command such as turning right at the next intersection, and roughly indicates the direction of travel of the mobile robot. In order to enable the operator to give a command to the mobile robot, an image of the moving direction side of the mobile robot is acquired by a camera mounted on the mobile robot. This image is transmitted to the remote control device away from the mobile robot and displayed on the display of the remote control device. The operator sees the displayed image and sets the operation for giving a command to the mobile robot as the operation unit of the remote control device. A command by this operation is transmitted to the mobile robot, and the route generation device of the mobile robot generates a movement route based on this command (for example, a direction command for changing the traveling direction to the right side or the left side). The control device of the mobile robot controls the movement of the mobile robot on this movement path (for example, Patent Document 1).

Patent No. 5494178

When remotely controlling the traveling direction of a semi-autonomous mobile robot, the following can be considered. When a command is given to bend the traveling direction of the mobile robot from the current traveling direction to the right or left by remote control, the route generator provided in the control device bends to the right or left from the current position of the mobile robot according to the command. Generate a route that extends. When there is an obstacle on this route, the route generator forms a plurality of candidate routes on both sides of the reference line using this route as a reference line, and selects a candidate route that does not interfere with the obstacle from these candidate routes. do.

However, candidate routes that do not interfere with obstacles may deviate significantly from the reference line. For example, as shown in FIG. 1, when the curvature of each candidate path is made constant, each candidate path always extends away from the reference line from the current position of the mobile robot. As a result, candidate routes that do not interfere with obstacles may deviate significantly from the reference line. For example, a mobile robot may move along the candidate route to avoid obstacles and then travel toward a roadside wall or curb.

Therefore, the purpose of the present technology is to generate a movement path of a mobile robot that does not interfere with obstacles based on a reference line and control the mobile robot by suppressing deviation from the reference line and providing a movement path along the reference line. The purpose is to increase the possibility of being generated.

In order to achieve the above-mentioned object, the device of the present technology is a control device for a mobile robot and is provided in the mobile robot.
This control device
An obstacle sensor that detects an obstacle from the mobile robot,
A route generator that generates a movement route based on the detected obstacle,
A control unit that controls the mobile robot according to the movement path is provided.
The route generator
A map generator that generates a map showing the position of the obstacle,
Based on a command from the outside of the mobile robot, in the map, a reference line generation unit that generates a reference line of the path of the mobile robot, and a reference line generation unit.
In the map, when the obstacle is present on the reference line, a candidate generation unit that generates a plurality of candidate routes that extend along the reference line and have a portion that bends toward the reference line.
It is provided with a selection unit that selects, as the movement route, the candidate route that does not interfere with the obstacle and has the highest degree of along the reference line from the plurality of candidate routes.

Further, in order to achieve the above-mentioned object, the method of the present technology is a control method of a mobile robot.
(A) An obstacle is detected from the mobile robot by an obstacle sensor provided on the mobile robot.
(B) Based on the detected obstacle, a movement route is generated by a route generator, and a movement route is generated.
(C) The mobile robot is controlled according to the movement path,
In (B) above,
(B1) Generate a map showing the position of the obstacle,
(B2) Based on a command from the outside of the mobile robot, a reference line of the route of the mobile robot is generated on the map.
(B3) In the map, when the obstacle is present on the reference line, a plurality of candidate routes extending along the reference line and having a portion that bends toward the reference line are generated.
(B4) From the plurality of candidate routes, the candidate route that does not interfere with the obstacle and has the highest degree of along the reference line is selected as the movement route.

According to the present technology, since the candidate generation unit forms a plurality of candidate routes having a portion that bends to the reference line side, there is an increased possibility that a plurality of candidate routes in which deviation from the reference line is suppressed can be generated. In addition, the selection unit selects, among these candidate routes, the candidate route that does not interfere with obstacles and has the highest degree of along the reference line as the movement route. Therefore, the possibility that the deviation from the reference line is suppressed and the movement path along the reference line can be generated increases.

It is explanatory drawing of the problem which this technology solves. A mobile robot provided with a control device according to an embodiment of the present technology is shown. It is a block diagram which shows the structure of the control device by embodiment of this technology. An example of the map generated by the map generator is shown. It is explanatory drawing which shows an example of the generation method of a candidate route. It is a flowchart which shows the control method by embodiment of this technique. It is explanatory drawing of the calculation method of the evaluation value which shows the degree along the reference line.

An embodiment of the present technology will be described with reference to the drawings. In addition, the same reference numerals are given to common parts in each figure, and duplicate description is omitted.

(Structure of mobile robot)
FIG. 2 shows a mobile robot 20 provided with a control device 10 according to an embodiment of the present technology. The mobile robot 20 may be a vehicle that has wheels 1 for traveling and travels on the ground surface 2 by being rotationally driven by the wheels 1. Alternatively, the mobile robot 20 may be a traveling device or other device traveling on the ground by a crawler. In the present embodiment, the mobile robot 20 may be configured as a semi-autonomous mobile robot.

(Configuration of control device and remote control device)
<Configuration to detect the status of obstacles and mobile robots>
FIG. 3 is a block diagram showing a configuration of the control device 10 according to the embodiment of the present technology. The control device 10 of this embodiment is provided in the mobile robot 20. The control device 10 includes an obstacle sensor 3, a speed sensor 5, an orientation sensor 7, and a position detection unit 9.

The obstacle sensor 3 detects an obstacle from the mobile robot 20. That is, the obstacle sensor 3 detects the position (coordinates) of the obstacle in the sensor coordinate system fixed to the mobile robot 20.

In the present embodiment, the obstacle sensor 3 acquires obstacle data in which the position of each obstacle existing in the measurement range is represented by the sensor coordinate system by measuring the measurement range seen from the mobile robot 20. do. The measurement range includes the range on the traveling direction side of the mobile robot 20. The origin of the sensor coordinate system is the position of the mobile robot 20 when the obstacle data is acquired. The acquisition of obstacle data by the obstacle sensor 3 is repeatedly performed while the mobile robot 20 is moving.

The obstacle sensor 3 is, for example, a laser radar. The laser radar scans the laser beam (for example, pulsed laser beam) with respect to the measurement range, and acquires the coordinates (for example, three-dimensional coordinates) of each measurement point based on the reflected laser beam from each measurement point on the object surface. do. The laser radar may be, for example, a device called LiDAR (Light Detection and Ranger) or LRF (Laser Range Finder). The obstacle sensor 3 is an imaging device (for example, a stereo camera) that acquires image data by imaging a measurement range and acquires obstacle data indicating the position of an obstacle by processing the image data. You may. Alternatively, the obstacle sensor 3 may be a combination of the above-mentioned laser radar and an imaging device.

The speed sensor 5 detects the magnitude (speed) of the speed of the mobile robot 20. The speed sensor 5 measures, for example, the rotation speed of the wheels 1 of the mobile robot 20 as a vehicle, and obtains the speed of the mobile robot 20 with respect to the map coordinate system fixed to the ground surface 2 from this rotation speed. However, it is not limited to this. For example, the speed sensor 5 may have a configuration for estimating the speed of the mobile robot 20 based on radio waves from a positioning satellite in a satellite navigation system, and this configuration and a configuration for measuring the rotation speed may be used. It may be a combination.

The orientation sensor 7 detects the orientation (that is, the traveling direction) of the mobile robot 20 with respect to the map coordinate system described above. The orientation sensor 7 may be configured using, for example, a gyro sensor, but is not limited thereto. For example, the orientation sensor 7 may have a configuration for estimating the orientation of the mobile robot 20 based on radio waves from a positioning satellite in a satellite navigation system, or may be a combination of this configuration and a gyro sensor. good. In the following, the current traveling direction of the mobile robot 20 may mean the latest orientation of the mobile robot 20 detected by the orientation sensor 7.

The position detection unit 9 obtains the current position of the mobile robot 20 in the above-mentioned map coordinate system. For example, the position detection unit 9 obtains the current position of the mobile robot 20 based on the speed measured by the speed sensor 5 and the direction detected by the orientation sensor 7. That is, the position detection unit 9 assumes that the moving robot 20 in the direction measured by the orientation sensor 7 moves at each time point at the speed detected by the speed sensor 5, and the moving robot is based on the speed and direction at each time point. Find the current position of 20. As an alternative or additional configuration to this configuration, the position detection unit 9 may have a configuration for obtaining the current position of the mobile robot 20 based on the radio waves from the positioning satellite in the satellite navigation system. In the following, the current position may mean the current position of the mobile robot 20 detected by the position detection unit 9.

<Configuration for remote control>
The mobile robot 20 includes a camera 11 and a communication unit 13. While the mobile robot 20 is moving, the camera 11 repeatedly images a region on the traveling direction side of the mobile robot 20. The communication unit 13 transmits / receives data to / from the remote control device 30 existing outside the mobile robot 20. The communication unit 13 sequentially transmits each image data repeatedly captured by the camera 11 to the remote control device 30.

The remote control device 30 includes a communication unit 15, a display 17, an operation unit 19, and a command generation unit 21. The communication unit 15 receives each image data transmitted from the communication unit 13 of the mobile robot 20. The display 17 sequentially displays each image data received by the communication unit 15. The remote control device 30 may be composed of a personal computer or a mobile terminal.

A person can operate the operation unit 19 by looking at the image data displayed on the display 17. In the present embodiment, the operation unit 19 can perform an operation related to the traveling direction of the mobile robot 20.
The command generation unit 21 generates a direction command according to the operation performed by the operation unit 19. The direction command gives direction information indicating whether the moving direction of the mobile robot 20 is bent to the right or left side from the current traveling direction of the mobile robot 20, and the amount of bending in the direction indicated by the direction information (right side or left side). Includes the indicated direction change amount.
The operation unit 19 may be, for example, a handle or a lever. When the operation unit 19 is a handle, the direction indicated by the above-mentioned direction information (that is, the above-mentioned right side or left side) is determined by turning the handle clockwise or counterclockwise from the reference rotation position. Further, the command generation unit 21 generates a larger amount of direction change as the amount of rotation of the handle from the reference rotation position is larger. When the operation unit 19 is a lever, the direction indicated by the above-mentioned direction information (that is, the above-mentioned right side or left side) is determined by operating (for example, tilting) the lever to the right or left side from the reference rotation position. Further, the command generation unit 21 generates a larger amount of direction change as the amount of operation of the lever from the reference rotation position is larger.
The operation unit 19 is not limited to the above-mentioned handle or lever. The generated direction command is transmitted from the communication unit 15 to the mobile robot 20. As a result, the communication unit 13 of the mobile robot 20 receives the direction command transmitted from the communication unit 15.

<Configuration for route generation and movement control based on remote control>
The control device 10 includes a route generation device 23. The route generation device 23 includes a map generation unit 23a, a reference line generation unit 23b, a candidate generation unit 23c, and a selection unit 23d.

The map generation unit 23a converts the obstacle data acquired by the obstacle sensor 3 into the data of the map coordinate system, and based on the converted data, the map generation unit 23a converts the obstacle in the map coordinate system fixed to the ground surface 2. Generate a map showing the position (for example, a local map). The above-mentioned conversion of the obstacle data is a coordinate conversion from the above-mentioned sensor coordinate system, and the direction of the mobile robot 20 detected by the orientation sensor 7 at the time of acquiring the obstacle data and the position detection unit 9 at the time of the acquisition are obtained. It may be performed based on the position of the mobile robot 20. FIG. 4A shows an example of a map generated by the map generation unit 23a. In FIG. 4, the shaded area indicates an obstacle.

The reference line generation unit 23b generates a reference line in the above map according to a command from the outside of the mobile robot 20 (that is, the above-mentioned direction command received by the communication unit 13). The generated reference line is a line extending from the current position of the mobile robot 20 to the side in the current traveling direction of the mobile robot 20 in response to a direction command. That is, the reference line extends from the current traveling direction (direction) of the mobile robot 20 in the direction indicated by the direction information of the direction command (right side or left side) so as to bend to a degree corresponding to the direction change amount of the direction command. ..
The reference line may be a curve (ie, an arc) having a constant curvature. In this case, the tangential direction of the reference line at the current position of the mobile robot 20 may coincide with the current traveling direction (direction) of the mobile robot 20. When the reference line is an arc, the curvature of the reference line increases as the amount of direction change of the direction command increases.
The length of the reference line may be a predetermined constant length, may be a braking distance with respect to the current speed detected by the speed sensor 5, or may be determined by another method. FIG. 4B shows an example of a reference line generated on the map of FIG. 4A.

In the above map, the candidate generation unit 23c has a plurality of candidate routes extending from the current position of the mobile robot 20 along the reference line and having a portion that bends to the reference line side when an obstacle exists on the reference line. To generate. FIG. 4C shows an example of a plurality of candidate routes generated with respect to the reference line of FIG. 4B. The plurality of candidate routes may be dispersedly formed on both sides of the reference line as shown in FIG. 4C, or may be formed only on one side of the reference line.

In the present embodiment, for each candidate route, the curvature of the candidate generation unit 23c continuously changes as it shifts from the start point of the candidate route (that is, the current position of the mobile robot 20) to the end point side of the candidate route. The candidate route may be generated. Each such candidate path may be a curve whose curvature changes continuously throughout the candidate path rather than a monotonous arc. Each candidate route may be, for example, a clothoid curve or a spline curve, but is not limited thereto.

FIG. 5 is an explanatory diagram showing an example of generation of a candidate route. Hereinafter, the method of generating one candidate route shown by the broken line in FIG. 5 will be described, but the method of generating another candidate route may be the same as the following. In FIG. 5, the x-axis and the y-axis are coordinate axes facing the horizontal direction of the above-mentioned map coordinate system, and are orthogonal to each other. The candidate generation unit 23c generates a candidate path having a curvature κ (S) represented by the following cubic polynomial.

κ (S) = a ₁ + a ₂ S + a ₃ S ² + a ₄ S ³

Here, a ₁ , a ₂ , a ₃ , and a ₄ are coefficients. At least one of a ₃ and a _4, may be a value other than zero (i.e., the candidate path both a ₃ and a ₄ becomes zero may not be generated). S is a variable and indicates the length along the candidate path from the current position Ps of the mobile robot 20 to the arbitrary position P on the candidate path. That is, S indicates the partial length of the candidate route. The upper limit value Se of S is the total length of the candidate route. In other words, S represents a position on the candidate route. For example, S = 0 represents the start point Ps of the candidate route (that is, the current position of the mobile robot 20), and S = Se represents the end point Pe of the candidate route.

ここで、θ（Ｓ）は、Ｓの値により定まる（候補経路上の）任意位置Ｐにおける候補経路の接線方向Ｄの向きを示し、ｘ軸とのなす角度θとして表わされる（図５を参照）。θ_０は、候補経路の始点Ｐｓにおける候補経路の接線方向の向きを示す。ｘ（Ｓ）は、地図座標系のｘ軸座標を示し、ｙ（Ｓ）は、地図座標系のｙ軸座標を示す。ｘ_０は、候補経路の始点Ｐｓのｘ座標であり、ｙ_０は、候補経路の始点Ｐｓのｙ座標である。 Candidate routes are specified by the above κ (S). That is, assuming that S is a variable that takes a value from 0 to Se, θ (S), x (S), and y (S) are determined by the following equations.

Here, θ (S) indicates the direction of the tangential direction D of the candidate path at an arbitrary position P (on the candidate path) determined by the value of S, and is represented as an angle θ formed with the x-axis (see FIG. 5). ). θ ₀ indicates the direction of the candidate route in the tangential direction at the start point Ps of the candidate route. x (S) indicates the x-axis coordinate of the map coordinate system, and y (S) indicates the y-axis coordinate of the map coordinate system. x ₀ is the x-coordinate of the start point Ps of the candidate route, and y ₀ is the y-coordinate of the start point Ps of the candidate route.

_{The candidate generation unit 23c obtains four unknown coefficients a 1} , a ₂ , a ₃ , and a ₄ in the equation of κ (S) according to the following four conditions (1) to (4). That is, the candidate generation unit 23c obtains the _{coefficients a 1} , a ₂ , a ₃ , and a ₄ that satisfy the conditions (1) to (4).
(1) The starting point Ps of the candidate route is the current position of the mobile robot 20.
(2) The end point Pe of the candidate route is a point set within the local range R (see FIG. 5) in which the distance from the end point Pr of the reference line is within the set distance.
(3) The tangential direction (direction) of the candidate path at the start point Ps is the current direction of the mobile robot 20.
(4) The tangential direction (direction) of the candidate path at the end point Pe is parallel to the tangential direction of the reference line at the end point Pr of the reference line.

The current position of (1) above is detected by the position detection unit 9 and input to the candidate generation unit 23c. The end point Pe of the above (2) is set by the candidate generation unit 23c, for example, randomly or according to a predetermined rule. The rule stipulates, for example, that the end point Pe is located on a horizontal straight line orthogonal to the reference line at the end point Pr of the reference line (in this case, the end points of the plurality of candidate routes are spaced on this straight line). Can be set). The current orientation of (3) above is detected by the orientation sensor 7 and input to the candidate generation unit 23c. The tangential direction of the reference line at the end point Pr of the reference line in (4) is input from the reference line generation unit 23b to the candidate generation unit 23c.

The selection unit 23d selects from a plurality of candidate routes the candidate route that does not interfere with obstacles and has the highest degree of along the reference line as the movement route. The calculation method of the degree will be described later. In the example of FIG. 4C, the candidate route to the left of the reference line is selected.

The control device 10 includes a control unit 25 that controls the drive device of the mobile robot 20 according to the candidate route selected by the selection unit 23d. By this control, the mobile robot 20 moves on the candidate route. The drive device of the mobile robot 20 is composed of, for example, a plurality of actuators that operate the accelerator, brake, steering, transmission, and the like of the vehicle as the mobile robot 20.

<Configuration for route generation and movement control when not remotely controlled>
The route generation device 23 further includes a route generation unit 23e. The route generation unit 23e generates the movement route of the mobile robot 20 when the communication unit 13 does not receive the above-mentioned direction command. In one example, the route generation unit 23e generates a movement route toward the next waypoint while avoiding obstacles from the current position of the mobile robot 20 in the above-mentioned map generated by the map generation unit 23a. The next waypoint is the waypoint that the mobile robot 20 passes next among the plurality of way points that the mobile robot 20 passes to move to the target position. The target position and a plurality of waypoints are preset.

In this case, the control unit 25 controls the drive device of the mobile robot 20 according to the movement path generated by the route generation unit 23e. By this control, the mobile robot 20 moves on the moving path.

<Configuration that recognizes branch roads>
The mobile robot 20 may be provided with a branch path recognition unit 26. The branch road recognition unit 26 recognizes the branch road based on the obstacle data acquired by the obstacle sensor 3. When the branch path recognition unit 26 recognizes the branch path, the branch path recognition unit 26 determines the position and orientation of the branch path (direction with respect to the current direction of the mobile robot 20) represented by the sensor coordinate system by a corresponding pixel calculation formula obtained in advance. The image data obtained by the camera 11 is converted into a position (pixel position) and orientation in the coordinate system. The positions and directions of the branch paths converted in this way are sent to the display 17 via the communication units 13 and 15, and are displayed on the display 17 overlaid on the above-mentioned image data.

Looking at such a display, the person operates the operation unit 27 for selecting the branch path (for example, the mouse or the touch panel in FIG. 2) to select the branch path on which the mobile robot 20 travels. For example, on the display 17, each mark is superimposed on the above-mentioned image data as the position of each of the above-mentioned branch paths, and the mouse 27 is operated by operating the mouse 27 to position the cursor on the mark of the selected branch path. By clicking, the branch road is selected. As a result, the branch road selection information indicating the selected branch road is transmitted to the route generation unit 23e via the communication units 15 and 13.

The route generation unit 23e, based on the received branch road selection information, passes through the branch road indicated by the branch road selection information to the next waypoint in the map generated by the map generation unit 23a without interfering with obstacles. Generate a moving route to go. The control unit 25 controls the drive device of the mobile robot 20 according to this movement path.

(Processing flow of control method)
<Control method when not receiving a direction command>
FIG. 6 is a flowchart showing a control method of the mobile robot 20 by the control device 10. The control method when the direction command is not received includes steps S1 to S4 shown in FIG. 6 (A).

While performing steps S1 to S4, the position and orientation detection process (hereinafter, simply referred to as detection process) is repeatedly performed. In the detection process, the position detection unit 9 detects the current position of the mobile robot 20, and the orientation sensor 7 detects the orientation of the mobile robot 20.

In step S1, the obstacle sensor 3 acquires obstacle data in which the position of each obstacle existing in the measurement range is represented by the sensor coordinate system as described above. Step S1 is repeated at a cycle longer than the cycle of the detection process described above.

In step S2, based on the obstacle data acquired in step S1 and the current position and orientation of the mobile robot 20 detected by the detection process when the obstacle data is acquired, the map generation unit 23a causes an obstacle in the map coordinate system. Generate a map showing the location of objects. Step S2 may be performed each time step S1 is performed. That is, step S2 may be performed in the same cycle as step S1. In the repeated map generation by the map generation unit 23a, the position of the obstacle in the map generated at each time in the past is also shown in the newly generated map.

In step S3, the route generation unit 23e generates a movement route toward the next waypoint in the map generated in step S2 without interfering with obstacles. Step S3 may be performed each time step S2 is performed, or may be performed in a cycle longer than the cycle of step S2. In the latter case, step S3 may be performed based on the latest map generated in the immediately preceding step S2.

When the route generation unit 23e receives the above-mentioned branch route selection information, the route generation unit 23e may perform step S3 as follows when the branch route selection information is received. Based on the latest map generated in step S2, a movement route to the next waypoint is generated through the branch road indicated by the branch road selection information without interfering with obstacles.

In step S4, the control unit 25 controls the drive device of the mobile robot 20 according to the movement path generated in step S3. As a result, the mobile robot 20 moves on the moving path. When a new movement route is generated in step S3, the control unit 25 switches the movement route used in step S4 to the newly generated movement route.

<Control method when receiving a direction command>
The control method when the direction command is received includes steps S11 to S17 shown in FIG. 6 (B). While the above steps S1 to S4 are being performed, a person can operate the operation unit 19 by looking at the image data of the display 17. By this operation, step S11 is started.

In step S11, the communication unit 13 of the mobile robot 20 receives the above-mentioned direction command.
In step S12, a line extending from the current position of the mobile robot 20 detected by the position detection unit 9, and a direction indicated by the direction information of the direction command from the current traveling direction (direction) of the mobile robot 20 detected by the orientation sensor 7. The reference line generation unit 23b generates a reference line that is bent (on the right side or the left side) to a degree corresponding to the amount of direction change of the direction command on the map. This map may be the latest map generated by the map generation unit 23a. In step S12, a reference line is generated as shown in FIG. 4B, for example.

In step S13, the candidate generation unit 23c determines whether or not an obstacle exists on the reference line generated in step S12. In step S13, if it is determined that an obstacle exists on the reference line, the process proceeds to step S14. If not, the candidate generation unit 23c outputs the reference line as a movement path to the control unit 25 and steps. Proceed to S17.

In step S14, as described above, the candidate generation unit 23c has a plurality of portions extending along the reference line (for example, on both sides of the reference line as shown in FIG. 4C) and having a portion that bends toward the reference line. Generate a candidate route.

In step S15, the selection unit 23d selects a candidate route that does not interfere with obstacles and has the highest degree of along the reference line as the movement route from the plurality of candidate routes. The selected candidate route is output from the selection unit 23d to the control unit 25.

For this selection, the selection unit 23d obtains an evaluation value indicating the degree of along the reference line for each candidate route. However, it is not necessary to obtain this evaluation value for the candidate route that interferes with the obstacle. Further, when there is only one candidate route that does not interfere with the obstacle, the selection unit 23d may select this candidate route without obtaining an evaluation value for this candidate route.

FIG. 7 is an explanatory diagram of a calculation method for obtaining the above-mentioned evaluation value. The selection unit 23d obtains the above-mentioned evaluation value by performing the following (1) and the following (2) to (4) for each candidate route.
(1) On the reference line, a plurality of dividing points spaced apart from each other are generated over the entire reference line. In the example of FIG. 7, each black circle on the reference line is a dividing point.
(2) On the candidate route, a plurality of break points spaced apart from each other are generated over the entire candidate route. In the example of FIG. 7, each black circle on the candidate route is a dividing point.
(3) For each break point on one of the candidate route and the reference line (reference line in FIG. 7), the break point and the other of the candidate route and the reference line (candidate route in FIG. 7) are closest to the break point. The distance from the dividing point (the length of the thin broken line in FIG. 7) is obtained.
(4) For each dividing point on one of the candidate route and the reference line, the total distance obtained in (3) above (the total length of each thin broken line in FIG. 7) is evaluated to the degree along the reference line. Obtain as a value. Assuming that the smaller the evaluation value is, the higher the degree is, the candidate route having the highest degree is selected from among the plurality of candidate routes that do not interfere with obstacles.

The interval between (1) and (2) may be, for example, a constant interval in the coordinate axis direction of the map coordinate system (for example, the vertical direction in FIG. 7). In this case, the interval (1) and the interval (2) may be different from each other. In this case, in (3) above, of the candidate route and the reference line, for each dividing point at the one having the larger interval (reference line in the example of FIG. 7), the dividing point and the candidate route and the reference line are On the other hand, the distance from the dividing point closest to the dividing point is obtained. An evaluation value indicating the degree of along the reference line may be obtained for each candidate route by a method different from the above (1) to (4).

In step S16, the control unit 25 controls the driving device of the mobile robot 20 according to the movement path selected in step S15. As a result, the mobile robot 20 moves on the moving path. As a result, when the mobile robot 20 moves to the end point of the movement path or before the end point, steps S3 and S4 may be performed. While performing steps S11 to S16, the above steps S1 and S2 are repeated as described above without interruption.

On the other hand, in step S17, the control unit 25 controls the driving device of the mobile robot 20 according to the reference line using the reference line generated in step S12 as the movement path. As a result, the mobile robot 20 moves on the reference line.

(effect)
The following is an example of the effect of the embodiment of the present technology, and does not limit the present technology.

In the above-described embodiment, the candidate generation unit 23c forms a plurality of candidate routes having a portion that bends to the reference line side, so that the possibility of generating a candidate route that suppresses deviation from the reference line increases. Further, since the selection unit 23d selects the candidate route having the highest degree of along the reference line as the movement route without interfering with the obstacle, the deviation from the reference line is suppressed and the reference line is suppressed. Can generate a movement path along.

When the selection unit 23d selects the candidate route having the highest degree of along the reference line from the plurality of candidate routes, the selection unit 23d generates a plurality of dividing points for each of the reference line and the candidate route. Then, the selection unit 23d obtains the distance between the dividing point and the dividing point closest to the dividing point on the other side of the candidate route and the reference line for each dividing point on one of the candidate route and the reference line. The selection unit 23d selects the candidate route having the smallest total distance obtained. In this way, since the processing may be performed for a plurality of break points, the time required for the processing for selecting the candidate route can be shortened.

Regarding this, the fixed interval of the dividing points on one of the candidate route and the reference line may be larger than the fixed interval of the other dividing point of the candidate route and the reference line. By increasing the interval between the other delimiters in this way, the time required for the process of selecting the candidate route can be further shortened.

The present technology is not limited to the above-described embodiment, and it goes without saying that various changes can be made within the scope of the technical idea of the present technology.

1 wheel, 3 obstacle sensor, 5 speed sensor, 7 direction sensor, 9 position detector, 10 control device, 11 camera, 13 communication unit, 15 communication unit, 17 display, 19 operation unit, 20 mobile robot, 21 command generation Unit, 23 route generator, 23a map generator, 23b reference line generator, 23c candidate generator, 23d selection unit, 23e route generator, 25 control unit, 26 branch road recognition unit, 27 operation unit, 30 remote control unit.

Claims (4)

A control device installed in a mobile robot
An obstacle sensor that detects an obstacle from the mobile robot,
A route generator that generates a movement route based on the detected obstacle,
A control unit that controls the mobile robot according to the movement path is provided.
The route generator
A map generator that generates a map showing the position of the obstacle,
Based on a command from the outside of the mobile robot, in the map, a reference line generation unit that generates a reference line of the path of the mobile robot, and a reference line generation unit.
In the map, when the obstacle is present on the reference line, a candidate generation unit that generates a plurality of candidate routes extending along the reference line and having a portion that bends toward the reference line.
A selection unit for selecting one of the plurality of candidate routes as the movement route is provided.
The selection unit
On the reference line, a plurality of dividing points at regular intervals from each other are generated.
For each candidate route that does not interfere with the obstacle
On the candidate route, generate a plurality of break points at regular intervals from each other.
For each of the dividing points on one of the candidate route and the reference line, the distance between the dividing point and the dividing point closest to the dividing point on the other side of the candidate route and the reference line is obtained.
The total of the distances obtained for each of the above-mentioned dividing points was obtained as an evaluation value.
The selection unit selects the candidate route having the smallest evaluation value as the movement route, and then selects the candidate route.
A control device for a mobile robot, wherein the fixed distance between the candidate route and the dividing point on the one of the reference lines is larger than the fixed distance between the candidate route and the other dividing point on the reference line. The map generation unit generates the map showing the position of an obstacle in the map coordinate system, and generates the map.
The fixed distance between the candidate route and the other dividing point of the reference line and the fixed distance between the candidate route and the other dividing point of the reference line are in the coordinate axis direction of the map coordinate system. The control device for a mobile robot according to claim 1 , which is an interval. It is a control method for mobile robots.
(A) An obstacle is detected from the mobile robot by an obstacle sensor provided on the mobile robot.
(B) Based on the detected obstacle, a movement route is generated by a route generator, and a movement route is generated.
(C) The mobile robot is controlled according to the movement path,
In (B) above,
(B1) Generate a map showing the position of the obstacle,
(B2) Based on a command from the outside of the mobile robot, a reference line of the route of the mobile robot is generated on the map.
(B3) In the map, when the obstacle is present on the reference line, a plurality of candidate routes extending along the reference line and having a portion that bends toward the reference line are generated.
(B4) One of the plurality of candidate routes is selected as the movement route, and the movement route is selected.
In (B4), the route generator
On the reference line, a plurality of dividing points at regular intervals from each other are generated.
For each candidate route that does not interfere with the obstacle
On the candidate route, generate a plurality of break points at regular intervals from each other.
For each of the dividing points on one of the candidate route and the reference line, the distance between the dividing point and the dividing point closest to the dividing point on the other side of the candidate route and the reference line is obtained.
The total of the distances obtained for each of the above-mentioned dividing points was obtained as an evaluation value.
The candidate route having the smallest evaluation value is selected as the movement route, and the movement route is selected.
A method for controlling a mobile robot, wherein the fixed distance between the candidate route and the dividing point in the one of the reference lines is larger than the fixed distance between the candidate route and the other dividing point of the reference line. In the above (B1), the map showing the position of the obstacle in the map coordinate system is generated, and the map is generated.
The fixed distance between the candidate route and the other dividing point of the reference line and the fixed distance between the candidate route and the other dividing point of the reference line are in the coordinate axis direction of the map coordinate system. The method for controlling a mobile robot according to claim 3, which is an interval.

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