JP7527856B2 - Working robot - Google Patents

Description

The present invention relates to a work robot that can navigate autonomously while performing tasks such as mowing grass.

Conventionally, there are known work robots that autonomously navigate within a work area and perform tasks such as weeding along a travel path (see, for example, Patent Document 1 below).

The work robot uses a satellite positioning system such as GPS, or detects reference positions such as electronic tags or wires installed at the work site, and navigates autonomously to position itself within the set work area.

Patent No. 5973608

When the aforementioned work robot reaches the boundary of the work area, it turns (pivots) the body a specified angle so that the direction of travel of the body faces into the work area.

At this time, the direction of the aircraft, which determines the direction of travel, is determined by the angle count of the turning operation and the detection value of the orientation sensor, but due to various factors such as the road surface conditions at the work site and sensor errors, a discrepancy may occur between the aircraft's orientation after turning and the set direction of travel.

When such a directional deviation occurs, the autonomous driving control is performed to correct it, but until the directional deviation is corrected, the work robot will be performing work outside of the set driving path. In particular, when trying to obtain a linear work trajectory by moving the robot in a straight line, the work trajectory will become meandering until the directional deviation after the turn is corrected, and a stable, linear work trajectory cannot be formed for several meters immediately after the turn.

Furthermore, many work robots that perform tasks such as mowing the grass have a circular working range when stopped. With such work robots, the working trajectory formed by autonomous driving becomes arc-shaped at the ends, so when the robot turns at the boundary position of the working area to work the entirety of the working area, there is a problem that unworked areas (in the case of mowing the grass, areas left uncut) are generated outside the arc-shaped working trajectory at the turning point.

Such unworked areas can be eliminated by having a work robot autonomously navigate along the outer edge of the work area to perform additional work, but this type of additional work inevitably results in many of the work trajectories overlapping with areas that have already been worked on, making the work inefficient.

The present invention has been proposed to address these problems. In other words, the objective of the present invention is to enable a work robot to form a work trajectory that follows a set travel route, and to efficiently eliminate unworked areas that remain outside the work trajectory.

In order to solve such problems, the present invention has the following configuration.
a control unit that controls the running unit to run autonomously, wherein the control unit controls a turning operation that turns the forward facing direction of the machine body toward inside a work area near a work boundary position, and controls a reverse operation that causes the machine body to run in a direction opposite to the forward facing direction before or after the turning operation , and the control of the reverse operation involves a reverse operation a distance equal to the radius of the working range of the working unit, thereby eliminating any unworked areas that occur outside the work trajectory .

A work robot with these characteristics can form a work trajectory along a set travel path, even when it repeatedly performs turning movements. In addition, a work robot with these characteristics can efficiently eliminate unworked areas that remain outside the work trajectory.

1A and 1B are explanatory diagrams showing the body configuration of a working robot ((a) is a side view, and (b) is a plan view). FIG. 1 is an explanatory diagram showing an example of a system configuration of a working robot. FIG. 1 is a block diagram of the system configuration of a work robot. FIG. 4 is an explanatory diagram showing an example of a program executed by a control unit. FIG. 4 is an explanatory diagram showing an example of a work operation of the working robot. 1A to 1C are explanatory diagrams showing basic movements performed by a working robot ((a) is a forward movement, (b) is a turning movement, and (c) is a backward movement). 1A and 1B are explanatory diagrams showing the basic movements of a work robot ((a) is a forward overrun movement, (b) is a backward movement, and (c) is a turning movement). FIG. 13 is an explanatory diagram of an example of a work operation incorporating a basic operation. FIG. 13 is an explanatory diagram of an example of a work operation incorporating a basic operation. FIG. 13 is an explanatory diagram of an example of a work operation incorporating a basic operation. FIG. 13 is an explanatory diagram of an example of a work operation incorporating a basic operation. FIG. 13 is an explanatory diagram of an example of a work operation incorporating a basic operation.

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts with the same function, and duplicate descriptions in each drawing will be omitted as appropriate.

As shown in FIG. 1, the working robot 1 includes a machine body 10. The machine body 10 includes a running unit 2 capable of autonomous running, a working unit 3 that performs tasks such as mowing, spraying, and collecting while running, and a drive unit 4 that drives the running unit 2 and the working unit 3. In the example shown in FIG. 1, the machine body 10 includes a control unit 5 that controls the running unit 2 to run autonomously. Here, an example is shown in which the control unit 5 is mounted on the machine body 10, but the control unit 5 may be provided away from the machine body 10 so as to remotely control the autonomous running of the running unit 2.

In the example shown in FIG. 1, the traveling unit 2 includes a front wheel traveling unit 2A and a rear wheel traveling unit 2B. The traveling unit 2 includes equipment that allows the machine body 10 to travel autonomously in any direction within a set working area. In the example shown in FIG. 1, the drive unit 4 includes a pair of front wheel drive units 4A and rear wheel drive units 4B on the left and right, and further includes a work drive unit 4C that drives the working unit 3. The machine body 10 is also provided with a battery 11 that serves as a power source for the front wheel drive unit 4A, rear wheel drive unit 4B, work drive unit 4C, control unit 5, etc.

In the working robot 1, the movements of the running unit 2 when running autonomously are forward movement, backward movement, and turning movement. The body 10 of the working robot 1 is structurally configured with a front side 10f and a rear side 10b. The movement of the running unit 2 that moves the body 10 toward the front side 10f of the body 10 is a forward movement, and the movement of the running unit 2 that moves the body 10 toward the rear side 10b of the body 10 is a backward movement. The movement of the running unit 2 that changes the direction of the front side 10f (or rear side 10b) of the body 10 while suppressing the progress of the body 10 is a turning movement (rotating movement).

The control unit 5 controls the forward, reverse, and turning motions of the traveling unit 2. In the example shown in FIG. 1, the front wheel drive unit 4A and the rear wheel drive unit 4B are controlled by a control signal from the control unit 5, thereby controlling the forward, reverse, and turning motions of the traveling unit 2. The control unit 5 also controls the work drive unit 4C.

The control unit 5 controls the left and right front wheel drive units 4A and the left and right rear wheel drive units 4B to operate the front wheel drive units 2A and the rear wheel drive units 2B so that the wheel circumferential speeds of the left and right wheels are all the same, allowing for straight forward movement. The control unit 5 controls the reverse movement by rotating the front wheel drive units 2A and the rear wheel drive units 2B in the opposite direction to the forward movement. The control unit 5 controls the turn movement by independently controlling the left and right front wheel drive units 4A or the left and right rear wheel drive units 4B, respectively, to create a difference in circumferential speed between the left and right front wheel drive units 2A and the left and right rear wheel drive units 2B.

The control signal output by the control unit 5 is, for example, output by calculation processing of the control unit 5, and as another example, is output based on a control signal (instruction signal) from a server (computer) that remotely controls the control unit 5 via a communication means, as described below.

The working unit 3 performs various tasks to form a work trajectory along the travel path of the machine body 10. The following describes an example of the working unit 3 performing grass cutting work. In the example shown in FIG. 1, the working unit 3 has a circular work range in a plan view, and cuts grass directly below the working unit 3 by rotating a grass cutting blade (not shown) around a vertical axis. As a result, when the working unit 3 is driven while the machine body 10 is traveling, a work trajectory of the completed grass cutting work is formed along the travel path of the machine body 10, with a width equal to the diameter of the circular work range of the working unit 3 in a plan view.

The body 10 of the working robot 1 is provided with a sensor unit 6. The sensor unit 6 is provided with various detection means for causing the traveling unit 2 to travel autonomously or for controlling the drive of the working unit 3. The sensor unit 6 is provided in the front of the body 10, and the detection signal of the sensor unit 6 is transmitted to the control unit 5.

Figure 2 shows an example of a system configuration for autonomous driving. In this example, a satellite positioning system (GNSS: Global Navigation Satellite System) such as GPS is used to detect the current position of the aircraft 10.

At this time, the sensor unit 6 of the aircraft 10 is provided with a GNSS sensor 6A that receives radio signals transmitted from GNSS satellites 100, and the signal received by the GNSS sensor 6A is transmitted to the control unit 5. The aircraft 10 is equipped with a communication unit 5A, and a server 101 in a remote location and a mobile information terminal 102 carried by a user at the work site can be connected to the control unit 5 via the communication unit 5A via the network NT.

An example of the configuration (block diagram) of the system shown in Fig. 2 is shown in Fig. 3. The control unit 5 of the machine body 10 is connected to the drive unit 4, sensor unit 6, and battery 11 described above, as well as to the communication unit 5A described above, the input unit 5B that inputs information to the control unit 5, and the memory unit 5C that stores the information input to the control unit 5.

The sensor unit 6 is provided with the GNSS sensor 6A described above, as well as a direction sensor 6B for detecting the direction in which the aircraft 10 is moving, and a boundary detection sensor 6C for physically detecting electronic tags and wires installed at the work boundary position.

The server 101 is provided with a control unit 50, which is connected to a communication unit 51 for connecting the server 101 to a network, an input unit 54 for inputting information to the control unit 50, a memory unit 52 for storing information input to the control unit 50, a display unit 53 for displaying the control status of the control unit 50 or the control unit 5, etc.

The communication unit 5A provided in the machine 10 and the communication unit 51 of the server 101 are connected via a network, so that the control unit 5 provided in the machine 10 and the control unit 50 of the server 101 can send and receive signals (information) to each other, forming a single integrated control unit 5U.

The control of the work robot 1 is executed by incorporating a program with the functions shown in FIG. 4 into the control unit 5U. The program executed by the control unit 5U shown in FIG. 4 can be incorporated in part or in whole into the control unit 5 mounted on the machine body 10, and can also be incorporated in part or in whole into the control unit 50 of the server 101. Also, a program with the same functions as the program incorporated into the control unit 5U can be incorporated into the control unit of the mobile information terminal 102 shown in FIG. 2.

When map information of the work site is already stored in the memory unit 5C (52), the map information acquisition means P1 imports the map information required to set the work area into the control unit 5U (5, 50). When map information is not stored in the memory unit 5C (52), the map information acquisition means P1 imports the necessary map information via the network NT and stores it in the memory unit 5C (52).

The work area setting means P2 sets a work area surrounded by a work boundary line (work boundary position) based on the imported map information and various input information.

The travel route setting means P3 sets a route along which the machine 10 will travel and perform work within the set work area.

The aircraft position detection means P4 detects the current position of the aircraft 10 within the working area based on the reception results of the GNSS sensor 6A and the acquired map information.

The boundary arrival detection means P5 detects that the current position of the aircraft 10 detected by the aircraft position detection means P4 has reached the vicinity of the work boundary position of the work area set by the work area setting means P2.

The forward movement execution means P6 executes a forward movement when it recognizes that the position of the machine 10 detected by the machine position detection means P4 is on the travel route set by the travel route setting means P3 along which the machine should move forward. In addition, when random travel is performed without setting a travel route before work, the machine 10 is made to travel straight after executing a turn operation described below.

When the boundary arrival detection means P5 detects that the machine body 10 has reached the vicinity of the work boundary position, the turn operation execution means P7 executes a turn operation at a predetermined timing to turn the forward direction of the machine body 10 toward the inside of the work area. When a travel route is set by the travel route setting means P3, the turn angle (rotation angle) when performing the turn operation is set so that the direction of the machine body 10 follows the route. When random travel is performed without setting a travel route before work, a predetermined turn angle is set for each turn operation so that work can be performed efficiently within the work area.

The reverse motion execution means P8 executes a reverse motion after or before the turn motion execution means P7 executes a turn motion. The travel distance when executing a reverse motion is set to the minimum distance required, for example, set to a travel distance of 1/2 the diameter (radius) of the circular working range of the working unit 3.

When the reverse motion execution means P8 executes a reverse motion before a turn motion, the overrun running execution means P9 causes the machine body 10, which has reached the work boundary position, to overrun the work boundary position by a set movement distance. The movement distance during overrun is set to the minimum distance required, for example, to a movement distance of 1/2 the diameter (radius) of the circular work range of the working unit 3.

The work operation execution means P10 starts driving the work drive unit 4C at a predetermined timing relative to the travel of the machine body 10, and stops driving the work drive unit 4C at a predetermined timing.

Below, an example of the work motion of the work robot 1 is described. In the example shown in FIG. 5, a work area Wa surrounded by a rectangular work boundary line (work boundary position) Wb is set, and a travel path Dr shown by a wavy line is set. Then, the machine body 10 travels straight ahead to form a linear work trajectory Wt, and then a work motion is performed in which the machine body 10 is turned near the work boundary position to change the forward direction of the machine body 10 to a substantially perpendicular direction, and the work motion is repeated.

In this type of work movement, if work is performed only with a straight forward movement and a turning movement with a turn angle of 90°, an unworked area (an area left uncut) Ua will be generated at the turning movement because the working unit 3 has a circular working range. Also, in the straight forward movement immediately after the turning movement, a directional deviation that occurs during the turning movement may not be able to be corrected by the detection of the orientation sensor 6B, and a stable linear work path may not be formed.

To eliminate such problems, the work robot 1 performs the basic operations shown in FIG. 6 or FIG. 7 when performing a turning operation under the control of the control unit 5U (5, 50).

The basic operation shown in FIG. 6 is as follows: As shown in FIG. 6(a), the working unit 3 of the machine body 10 moves forward until the working range of the working unit 3 reaches the work boundary line Wb, and when the working range of the working unit 3 reaches the work boundary line Wb, as shown in FIG. 6(b), it turns toward the working area Wa at a predetermined turn angle (90° in the illustrated example), and then, as shown in FIG. 6(c), it moves backwards the machine body 10 a distance equal to the radius of the working range. The operations at this time are performed in the order of (a), (b), and (c).

The basic operation shown in FIG. 7 is as follows: As shown in FIG. 7(a), the working unit 3 of the machine body 10 moves forward until the working range of the working unit 3 reaches the working boundary line Wb. When the working range of the working unit 3 reaches the working boundary line Wb, the machine body 10 overruns and moves forward a distance equal to the radius of the working range. Then, as shown in FIG. 7(b), the machine body 10 moves backward a distance equal to the radius of the working range. Then, as shown in FIG. 7(c), the machine body 10 turns toward the working area Wa at a predetermined angle (90° in the illustrated example). The operations are performed in the order of (a), (b), and (c).

By performing these basic operations while autonomously traveling in the work area Wa, the work robot 1 can efficiently eliminate the unworked area Ua shown in FIG. 5. Furthermore, when performing a reverse movement after a turn movement, as in the basic operation shown in FIG. 6, the direction deviation that occurs during the turn movement can be corrected by detection from the orientation sensor 6B based on the positional fluctuation of the body 10 detected by the GNSS sensor 6A while performing the reverse movement. This allows a stable, linear work trajectory to be formed from the start of the movement when a forward movement is subsequently performed.

Figures 8 to 12 show examples of work movements that incorporate one or both of the two basic movements described above. Each basic movement is performed in the order of (a), (b), and (c). The example shown in Figure 8 incorporates the basic movements shown in Figure 6 to form a straight striping work trajectory in which the moving direction of the working unit 3 alternates within the work area Wa surrounded by the rectangular work boundary line Wb.

The example shown in Figure 9 incorporates the basic operations shown in Figure 7 to form a straight striping work trajectory in which the working unit 3 moves in alternating directions within a work area Wa surrounded by a rectangular work boundary line Wb.

The example shown in Figure 10 incorporates the basic operations shown in Figures 6 and 7 to form a straight striping work trajectory in which the direction of movement of the working unit 3 alternates within a work area Wa surrounded by a rectangular work boundary line Wb, and also forms a neat overall pattern outside the work area Wa.

The example shown in Figure 11 incorporates the basic operations shown in Figure 7 to form a rotating stripe-shaped work trajectory within a work area Wa surrounded by a rectangular work boundary line Wb.

The example shown in Figure 12 incorporates the basic movements shown in Figure 7 and creates a work trajectory for random straight-line work by setting the turn angle appropriately.

In the above explanation, an example is given in which a global navigation satellite system (GNSS) is utilized, but the GNSS sensor 6A in the sensor unit 6 may be omitted, and the aforementioned boundary arrival detection means P5 may be executed using only the boundary detection sensor 6C that physically detects electronic tags and wires installed at the work site.

In this case, the work robot 1 is provided with a boundary detection sensor 6C in front of the machine body 10, and the boundary detection sensor 6C detects when the work robot 1 is heading toward the wire or the like and performs overrun driving. Since the work robot 1 always approaches the wire or the like by moving forward, there is no need to provide a boundary detection sensor 6C behind the work robot 1.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention includes design changes and the like that do not deviate from the gist of the present invention. In addition, the above-mentioned embodiments can be combined by reusing each other's technologies, as long as there are no particular contradictions or problems in the purpose, configuration, etc.

1: Working robot,
2: Running section, 2A: Front wheel running section, 2B: Rear wheel running section,
3: Working section,
4: Drive unit, 4A: Front wheel drive unit, 4B: Rear wheel drive unit,
4C: Work drive unit,
5, 50, 5U: control unit, 5A, 51: communication unit,
5B, 54: input section, 5C, 52: memory section, 53: display section,
6: sensor unit, 6A: GNSS sensor,
6B: orientation sensor, 6C: boundary detection sensor,
10: fuselage, 10f: front side, 10b: rear side,
11: Battery,
100: GNSS satellite, 101: server, 102: mobile information terminal,
NT: Network,
P1: map information acquisition means, P2: work area setting means,
P3: travel route setting means, P4: aircraft position detection means,
P5: boundary arrival detection means, P6: forward motion execution means,
P7: turn operation execution means, P8: reverse operation execution means,
P9: overrun running execution means, P10: work operation execution means

Claims (9)

An aircraft equipped with a traveling unit capable of autonomous traveling;
A working unit provided on the machine body and forming a working trajectory along a travel path of the machine body;
A drive unit provided on the machine body and configured to drive the traveling unit and the working unit;
A control unit that controls the traveling unit to perform autonomous traveling,
The control unit controls a turning operation that turns the forward facing of the machine body toward inside the work area near a work boundary position, and controls a reverse operation that causes the machine body to travel in the opposite direction to the forward facing direction before or after the turning operation , and the control related to the reverse operation involves a reverse operation a distance equal to the radius of the work range of the working unit, thereby eliminating unworked areas that occur outside the work trajectory . The control unit is
2. The work robot according to claim 1, wherein the reverse movement performed after the turning movement is controlled in order to adjust the forward direction of the body to match the intended direction of travel based on the detected positional fluctuation of the body. The control unit is
2. The working robot according to claim 1, wherein the control relating to the reverse movement, which is performed before the turning movement, is performed after the robot body has overrun a working boundary position. The work robot according to claim 3, characterized in that a sensor that physically detects the work boundary position is provided at the front of the body. The control unit is
5. The working robot according to claim 1, wherein the robot is controlled so that the body travels in a straight line to form the linear working trajectory, and then the body is controlled so as to repeatedly change the forward orientation to a substantially perpendicular orientation by the turning motion. The control unit is
5. The working robot according to claim 1, wherein the robot is controlled so that the body travels in a straight line to form the linear working trajectory, and then the body is controlled so as to repeatedly change the forward orientation in any direction by performing the turning motion. The work robot according to any one of claims 1 to 6, characterized in that the control unit is mounted on the machine body. The working robot according to any one of claims 1 to 6, characterized in that the control unit is provided in a server that remotely controls the autonomous driving of the driving unit via a communication means. The working robot according to any one of claims 1 to 8, characterized in that the working unit is equipped with a grass cutting blade that rotates around a vertical axis.