Autonomous Mobile Robot System

Abstract

To provide an autonomous travel robot system capable of maintaining an autonomous movement function even if abnormality occurs in a portion of sensors.SOLUTION: A robot system recognizes a self position on the basis of previously stored map information and traveling road information, and detects an obstacle on a traveling road with a main sensor 55 and sub sensors 52, 54 for assisting the main sensor to autonomously travel. Then, the robot system temporarily stops the sub sensors to continue traveling in the case where the sub sensors are affected by disturbance and the self position is in a preset specific area. The operation of the robot system is maintained by stopping the function of a portion of the sub sensors in the specific area in which the sensors easily become an abnormal state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an autonomous mobile robot system that moves autonomously based on pre-created map information and route information. [Background technology]

[0002] As an example of this type of system, Patent Document 1 describes an autonomously traveling work device that performs work while efficiently avoiding obstacles within a work area. This work device performs autonomous traveling cleaning, traveling autonomously and cleaning automatically based on a pre-stored cleaning plan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2020-194415 Summary of the Invention [Problem to be solved by the invention]

[0004] The working device in Patent Document 1 is equipped with obstacle sensors such as an ultrasonic sensor that detects the presence or absence of obstacles within a predetermined distance from the device body, and an infrared sensor that detects steps on the floor near the device body, and by correcting travel data using avoidance data for traveling while avoiding unknown obstacles, the working device is able to maintain a required distance from obstacles.

[0005] However, autonomous driving and automated operations are premised on the obstacle sensors working normally, and if the obstacle sensors go into an abnormal state, autonomous driving cannot be maintained.

[0006] The present invention has been made in consideration of the above circumstances, and its purpose is to provide an autonomous mobile robot system that can maintain its autonomous movement function even if an abnormality occurs in some of the sensors. [Means for solving the problem]

[0007] An autonomous mobile robot system according to one aspect of the present invention includes pre-stored map information and , including the surrounding environment and the specific area Track information and It recognizes its own position based on the main sensor 、 At least one type of sub-sensor , and bumper sensors A system that detects obstacles on the road and travels autonomously, The main sensor and the bumper sensor are always in an activated state, The sub-sensor is affected by a disturbance and its own position is in a predetermined unique region, A location where the bumper can collide with or come into contact with an obstacle and stop In this case, the sub-sensor is temporarily stopped to stop driving. Continue, It is characterized by: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an autonomous mobile robot system that can maintain its autonomous movement function even if an abnormality occurs in some of the sensors. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view illustrating an autonomous traveling robot system according to an embodiment of the present invention, showing a self-propelled floor cleaning device as an example. FIG. [Figure 2] FIG. 2 is a schematic bottom view of the self-propelled floor cleaning device shown in FIG. [Figure 3] 2 is a cross-sectional view showing the main internal parts of the self-propelled floor cleaning device shown in FIG. 1, corresponding to the cross section AA in FIG. 1. FIG. [Figure 4] 2 is a perspective view of a cleaning unit in the self-propelled floor cleaning device shown in FIG. 1. FIG. [Figure 5] 2 is a block diagram showing the configuration of a control system in the self-propelled floor cleaning device shown in FIG. 1. FIG. [Figure 6] 2 is a flowchart illustrating an example of the operation of the self-propelled floor cleaning device shown in FIG. 1, for explaining the operation of the autonomously traveling robot system according to the embodiment of the present invention. [Figure 7] 10 is a flowchart showing the setting of an ultrasonic sensor. [Figure 8] 10 is a flowchart showing the setting of a 3D sensor. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a self-propelled floor cleaning device as an example of an autonomous mobile robot system according to an embodiment of the present invention. Fig. 2 is a schematic bottom view of the self-propelled floor cleaning device shown in Fig. 1. Fig. 3 shows the main internal parts of the self-propelled floor cleaning device, and corresponds to the cross section AA in Fig. 1. Fig. 4 is a perspective view of a cleaning unit in the self-propelled floor cleaning device shown in Fig. 1, and Fig. 5 is a block diagram showing the configuration of a control system in the self-propelled floor cleaning device. The self-propelled floor cleaning device in this embodiment has a built-in power source such as a battery, but this power source is shown as a power supply unit 20 in FIG. 5, and a specific configuration and description thereof will be omitted.

[0011] 1 to 5, a self-propelled floor cleaning device 1 according to this embodiment (hereinafter simply referred to as the "floor cleaning device") has a traveling unit 2 for self-propelling on a floor surface. The traveling unit 2 is disposed at the bottom of the floor cleaning device 1. In this embodiment, the traveling unit 2 includes traveling motors 21, 21, a pair of left and right drive wheels 22, 22 driven by the traveling motors 21, 21, and a pair of left and right driven wheels 23, 23. The pair of left and right drive wheels 22, 22 are disposed at the bottom rear side of the floor cleaning device 1, and the pair of left and right driven wheels 23, 23 are disposed at the bottom front side of the floor cleaning device 1. The traveling motors 21, 21 drive (rotate) the pair of drive wheels 22, 22 under the control of the control device 10, thereby causing the floor cleaning device 1 to travel on the floor surface. Note that, although a pair of left and right driven wheels 23, 23 are provided here, this is not limiting and the number of driven wheels may be one.

[0012] The floor cleaning device 1 according to this embodiment also includes a cleaning unit 3 therein for cleaning the floor surface, as shown in Fig. 4. The cleaning unit 3 is disposed inside the floor cleaning device 1 between a pair of left and right drive wheels 22, 22 and a pair of left and right driven wheels 23, 23 in the front-to-rear direction.

[0013] Referring mainly to Figures 3 and 4, the cleaning unit 3 has a drive shaft 31 extending in the vertical direction, a shaft drive section 32 that drives the drive shaft 31, and a cleaning pad 33 attached to the drive shaft 31.

[0014] The shaft drive unit 32 accommodates the upper end of the drive shaft 31. The shaft drive unit 32 is configured to be able to move the drive shaft 31 back and forth in the vertical direction and rotate (including pivoting; the same applies below). Specifically, in this embodiment, the shaft drive unit 32 is configured to be able to advance the drive shaft 31 downward, retract the advanced drive shaft 31 upward, and rotate the drive shaft 31 in both forward and reverse directions at any advanced position. For example, the shaft drive unit 32 may include a drive motor capable of forward and reverse rotation, a rotation transmission mechanism that transmits the rotation of the drive motor to the drive shaft 31, a conversion mechanism that converts the rotation of the drive motor into linear motion in the axial direction of the drive shaft 31, and a coupling mechanism that connects the drive motor to the rotation transmission mechanism or the conversion mechanism. However, this is not limited thereto, and the shaft drive unit 32 may separately include a first drive unit that moves the drive shaft 31 back and forth and a second drive unit that rotates the drive shaft 31.

[0015] The cleaning pad 33 is formed in a circular shape in a plan view, and its center is attached to the lower end of the drive shaft 31. The cleaning pad 33 is composed of a pad holding part 331 fixed to the lower end of the drive shaft 31, and a pad member 332 removably attached to the lower surface of the pad holding part 331. The pad holding part 331 is formed as a rigid body. The pad member 332 is a member that comes into contact with the floor surface and is formed of an elastic body.

[0016] When the floor cleaning device 1 cleans the floor surface, the shaft drive unit 32, under the control of the control device 10, advances the drive shaft 31 downward from the initial position to the first advanced position, thereby lowering the cleaning pad 33 from the standby position to the cleaning position and bringing it into contact with the floor surface, and in this state rotates the drive shaft 31 to rotate the cleaning pad 33. In other words, the cleaning unit 3 rotates the cleaning pad 33 (pad member 332) in a state in which it is in contact with the floor surface, or more specifically, in a state in which the cleaning pad 33 (pad member 332) is pressed against the floor surface.

[0017] 1, an operation panel 4 is provided on the top of the floor cleaning device 1. In this embodiment, the operation panel 4 has a touch panel unit 41 that allows various information to be input and can display various information. The operation panel 4 also has various operation units arranged thereon, including a mode selection switch 42 for selecting the operation mode of the floor cleaning device 1 and an emergency stop button 43 for emergency stopping the floor cleaning device 1.

[0018] Additionally, on the front of the floor cleaning device 1, an information display unit 51, a 3D sensor 52, a camera 53, ultrasonic sensors 54, 54, a 2D-LiDAR (Light Detection And Ranging) 55, and a bumper sensor 56 are arranged in this order from top to bottom. The 2D-LiDAR 55 is used as the main sensor, and the 3D sensor 52 and the ultrasonic sensors 54, 54 are used as sub-sensors that assist the main sensor. The floor cleaning device 1 recognizes its own position using these sensors and detects obstacles on the running path to travel autonomously. The operating conditions of this floor cleaning device 1 can be recorded (video recorded) by the camera 53.

[0019] The information display unit 51 is configured to be able to display the status of the floor cleaning device 1, for example, that the floor cleaning device 1 is currently cleaning or that an abnormality has occurred in the floor cleaning device 1. The 3D sensor 52 detects steps on the floor surface and obstacles ahead of the floor cleaning device 1. The 2D-LiDAR 55 is used to estimate the self-position and detect obstacles ahead of the floor cleaning device 1. The 2D-LiDAR 55 and 3D sensor 52 are also used mainly to acquire shape data and the like of a predetermined range ahead of the floor cleaning device 1.

[0020] The ultrasonic sensors 54, 54 are used to detect objects at close range and are mainly used to detect obstacles in front of the floor cleaning device 1. The ultrasonic sensors 54, 54 are suitable for detecting transparent glass and the like that is difficult to detect with optical sensors such as the 2D-LiDAR 55 and the 3D sensor 52. The bumper sensor 56 is used for safety stopping in the event of a collision, and if the floor cleaning device 1 is about to collide with or come into contact with an obstacle or the like, it detects this situation and outputs an emergency stop signal to the control device 10 to bring the floor cleaning device 1 to an emergency stop.

[0021] The operation of the floor cleaning device 1 is controlled comprehensively by a control device 10. As shown in Fig. 5, the control device 10 is provided with an operation control unit 101, a work path setting and storage unit 102, a sensor condition setting unit 103, a sensor processing unit 104, and the like. The operation control unit 101 controls the driving of the traveling motors 21, 21 to control the traveling of the traveling unit 2, and also controls the driving of the shaft driving unit 32 to perform cleaning by the cleaning unit 3. The work path setting and storage unit 102 stores map information previously stored by traveling along a work path, and travel path information including the surrounding environment and unique areas.

[0022] Here, the peculiar area refers to a dead end or narrow section of the roadway, or a location where reflected light or ambient light may be received. For example, the ultrasonic sensors 54, 54 may falsely detect a vehicle in a dead end near a wall due to the echo of ultrasonic waves, and may also falsely detect a vehicle when passing through a narrow section such as a door or gate due to the echo of ultrasonic waves. On the other hand, the 3D sensor 52 may falsely detect a vehicle when receiving reflected light or ambient light from glass or a mirrored surface.

[0023] Furthermore, various conditions such as data and information obtained from the 2D-LiDAR 55, the 3D sensor 52, and the ultrasonic sensors 54, 54, as well as threshold values, are set in the sensor condition setting unit 103. The sensor processing unit 104 processes the data and information obtained by the 2D-LiDAR 55, the 3D sensor 52, and the ultrasonic sensors 54, 54, and calculates the self-position, the presence or absence of an obstacle, the distance to the obstacle, etc. Furthermore, when the bumper sensor 56 detects a situation in which the floor cleaning device 1 is about to collide with or come into contact with an obstacle or the like, an emergency stop signal is input to the operation control unit 101, and the operation control unit 101 stops the traveling unit 2 and the cleaning unit 3, thereby bringing the floor cleaning device 1 to an emergency stop.

[0024] In the above configuration, for example, when the manual cleaning mode is selected by the mode selection switch 42, the control device 10 operates the floor cleaning device 1 in the manual cleaning mode. In this case, the operator grips the pair of left and right handles 5, 5 provided on the upper rear side of the floor cleaning device 1, and the control device 10 operates the floor cleaning device 1 based on input by the operator via the operation panel 4 or the like. In the manual cleaning mode, when the operator inputs a cleaning start command, the control device 10 controls the shaft drive unit 32 of the cleaning unit 3 to start cleaning the floor surface with the cleaning unit 3, and controls the travel motors 21, 21 of the traveling unit 2 to start traveling of the floor cleaning device 1. Furthermore, when the operator inputs a command to change the traveling direction, the control device 10 controls the travel motors 21, 21 of the traveling unit 2 to change the traveling direction of the floor cleaning device 1 in accordance with the change command. Then, when the worker inputs a command to end cleaning, the control device 10 controls the shaft drive unit 32 of the cleaning unit 3 to end cleaning of the floor surface by the cleaning unit 3, and controls the running motors 21, 21 of the running unit 2 to stop the running of the floor cleaning device 1.

[0025] On the other hand, when the automatic cleaning mode is selected by the mode selection switch 42, the control device 10 operates the floor cleaning device 1 in the automatic cleaning mode. In this case, the control device 10 estimates the position (self-position) of the floor cleaning device 1 based on map information of the target cleaning area and information acquired by the 2D-LiDAR 55, and cleans the floor surface with the cleaning unit 3 while causing the floor cleaning device 1 to travel along a cleaning route in the cleaning area that has been created in advance. Furthermore, if the control device 10 detects an obstacle ahead of the floor cleaning device 1, it stops the travel of the floor cleaning device 1 and puts the floor cleaning device 1 into a standby state, and then resumes the travel of the floor cleaning device 1 when an obstacle is no longer detected ahead of the floor cleaning device 1. Furthermore, the control device 10 brings the floor cleaning device 1 to an emergency stop when the emergency stop button 43 is operated or an emergency stop signal is input from the bumper sensor 56.

[0026] FIG. 6 is a flowchart showing in detail an example of the operation of the floor cleaning device 1 in the automatic cleaning mode described above. First, a travel route (cleaning route) for the target cleaning area is created (step S1). The travel route is created by acquiring map information and travel path information based on the target cleaning area being operated by an operator or autonomously traveling under the operator's supervision. At this time, the shaft drive section 32 of the cleaning unit 3 may or may not lower the cleaning pad 33 from the standby position to the cleaning position by advancing the drive shaft 31 downward from the initial position to the first advanced position. In other words, the cleaning pad 33 (pad member 332) may or may not come into contact with the floor surface to actually perform cleaning.

[0027] When creating this travel route, the characteristics of the travel route are confirmed in advance, and the presence or absence of peculiar areas where sub-sensors are affected by disturbances is confirmed. If a peculiar area is detected, the location and the malfunctioning sub-sensor are stored. Generally, in the case of ultrasonic sensors 54, 54, peculiar areas are dead ends and narrow sections of the travel path. In the case of 3D sensors 52, these are places that may be subject to reflected light and disturbance light. Then, in these peculiar areas, sub-sensors whose functioning can be disabled without causing any major problems are identified, and the location information of the peculiar area and information on which sub-sensors to disable are stored.

[0028] In the next step S2, cleaning is performed while autonomously moving based on the map information and road information previously acquired in the above-mentioned step S1 (start of traveling). While the floor cleaning device 1 is traveling, all sensors are activated and these sensors detect obstacles to determine whether or not the device has stopped traveling (step S3). That is, based on the map information and travel route information previously stored in the work route setting and storage unit 102, the sensor processing unit 104 determines whether or not the device's own position acquired from the 2D-LiDAR 55 is in a previously set peculiar area. At this time, the 3D sensor 52, ultrasonic sensors 54, 54, and bumper sensor 56 are activated to ensure safety by anticipating all possible situations.

[0029] If it is determined that there is no travel stop, in other words that the robot is not in a peculiar area, it continues to travel along the travel route while continuing to perform cleaning, and when the robot has traveled the entire travel route, cleaning is completed (step S4). On the other hand, if it is determined in step S3 that the vehicle has stopped traveling, it is determined whether or not the control device 10 has detected an abnormality (step S5). If it is determined that an abnormality has been detected, the sensor is identified (step S6), and it is determined whether or not the on / off setting of the sensor can be changed (step S7).

[0030] If it is determined in step S7 that the change is possible, the sensor on / off setting is changed and the process returns to step S2 (step S8). The sensor on / off setting is changed as follows: The 2D-LiDAR 55, which is the main sensor, is kept in a constant operating state. Furthermore, the bumper sensor 56 is used for a safety stop in the event of a collision or contact with an obstacle, and is therefore kept in a constant operating state. In contrast, the 3D sensor 52, which is a sub-sensor, turns off in narrow areas such as dead ends and doors, and the ultrasonic sensors 54, 54, which are also sub-sensors, turn off in places affected by reflected light or ambient light.

[0031] However, the sub-sensor is turned off only in places where it is acceptable for the bumper of the floor cleaning device 1 to collide with or come into contact with an obstacle and stop. It is not turned off when there is a possibility that something that the sensor should detect is located there. Furthermore, it is turned on as normally as possible or as necessary, but is turned off when there is any doubt in light of the surrounding sensors and the device's own position.

[0032] If it is determined in step S5 that no abnormality has been detected, or if it is determined in step S7 that it is not possible, the environment or conditions are changed, such as by correcting the travel route or removing obstacles, and the process returns to step S2 (step S9).

[0033] Conventionally, vehicles are equipped with multiple types of sensors as safety features to anticipate all possible situations, but this can also lead to situations where factors that hinder driving increase. Therefore, the use of sub-sensors is controlled on / off based on map information and self-location information. In other words, the main sensor is always active, and in specific locations where it is prone to malfunction, the system determines whether the sub-sensors are on / off, and if it determines that a malfunction has occurred or is likely to occur, the system turns off the sub-sensor, allowing the vehicle to maintain autonomous driving (operation).

[0034] Fig. 7 is a flowchart showing on / off settings when the sensor identified in step S6 of Fig. 6 is the ultrasonic sensor 54, and corresponds to the steps enclosed by the dashed line in Fig. 6. When an abnormality occurs in the ultrasonic sensor 54, it is first determined whether obstacle detection is being covered by other sensors (step S11), and if so, it is determined whether a transparent object such as glass will be installed later (step S12). If a transparent object such as glass will not be installed later, the ultrasonic sensor 54 in the false detection section (peculiar area) is turned off (step S13).

[0035] If it is determined in step S11 that the obstacle detection is not covered by the other sensors, it is determined whether there is a detection target for the ultrasonic sensor, such as glass (step S14). If it is determined in step S14 that there is a detection target, or if it is determined in step S12 that a transparent object such as glass will be installed later, it is determined whether there will be any problems if the vehicle collides with the bumper (step S15).

[0036] If it is determined in step S15 that there is no problem, the process proceeds to step S13, where the ultrasonic sensors 54 in the erroneous detection section are turned off, and the setting is completed. If it is determined in step S15 that there is a problem, the environment or conditions are changed, such as by correcting the travel route or removing obstacles (step S16), and the setting is completed. When the ultrasonic sensor 54 is stopped, an alert is displayed on the touch panel unit 41 to notify the operator that the sub-sensor has been stopped and driving is continuing, and a release mark is displayed on the map to let the operator know that the release has been intentionally made.

[0037] Fig. 8 is a flowchart showing on / off settings when the sensor identified in step S6 of Fig. 6 is the 3D sensor 52, and corresponds to the steps surrounded by the dashed line in Fig. 6. When an abnormality occurs in the 3D sensor 52, it is first determined whether obstacle detection is covered by other sensors (step S21), and if so, it is determined whether an object smaller than the height of the 2D-LiDAR 55 is placed (step S22). If no small object is placed, the 3D sensor 52 in the false detection section (peculiar area) is turned off (step S23).

[0038] If it is determined in step S21 that the other sensors cannot cover obstacle detection, it is determined whether or not there is a detection target for the 3D sensor 52, such as a step (step S24). If it is determined in step S24 that there is a detection target, or if it is determined in step S22 that an object smaller than the height of the 2D-LiDAR 55 will be placed, it is determined whether or not there will be any problems if the vehicle collides with the bumper (step S25).

[0039] If it is determined in step S25 that there is no problem, the process proceeds to step S23, where the 3D sensors 52 in the erroneous detection section are turned off, and the setting is completed. If it is determined in step S25 that there is a problem, the environment or conditions are changed, such as by correcting the travel route or removing obstacles (step S26), and the setting is completed. In this case, too, when the 3D sensor 52 is stopped, an alert is displayed on the touch panel unit 41 to notify the operator that the sub-sensor has been stopped and driving is continuing, and a release mark is displayed on the map to let the operator know that the release has been intentional.

[0040] In this way, in an autonomous mobile robot system, by determining whether to turn on or off some sensor functions while taking into consideration the characteristics of the route to be traveled and safety, it is possible to simplify the travel control program and reduce costs, while also allowing the robot to continue traveling even in places where sensor abnormalities are likely to occur. Therefore, it is possible to provide an autonomous mobile robot system that can maintain its autonomous movement function even if an abnormality occurs in some of the sensors.

[0041] The configurations and control procedures described in the above embodiments are merely schematic illustrations to enable the present invention to be understood and implemented. Therefore, the present invention is not limited to the described embodiments, and can be modified in various forms without departing from the scope of the technical idea set forth in the claims.

[0042] For example, the above explanation has been given using a self-propelled floor cleaning device as an example, but it is not limited to self-propelled floor cleaning devices, and can of course be similarly applied to other autonomous mobile robot systems, such as security robots that patrol the floor. [Explanation of symbols]

[0043] 1...Self-propelled floor cleaning device (floor cleaning device), 2...Traveling unit, 3...Cleaning unit, 4...Operation panel, 10...Control device, 21...Travel motor, 22...Drive wheel, 23...Driven wheel, 31...Drive shaft, 32...Shaft drive unit, 33...Cleaning pad, 51...Information display unit, 52...3D sensor (sub-sensor), 53...Camera, 54...Ultrasonic sensor (sub-sensor), 55...2D-LiDAR (main sensor), 56...Bumper sensor, 101...Operation control unit, 102...Work path setting / storage unit, 103...Sensor condition setting unit, 104...Sensor processing unit

Claims

1. A system that recognizes its own position based on pre-stored map information and road information including the surrounding environment and unique areas, and detects obstacles on the road using a main sensor, at least one type of sub-sensor, and a bumper sensor, and autonomously travels, The main sensor and the bumper sensor are always in an activated state, An autonomous driving robot system that temporarily stops the sub-sensor and continues driving when the sub-sensor is affected by external disturbances, the robot's own position is in a predetermined unique area, and it is acceptable for the bumper to collide with or come into contact with an obstacle and stop.

2. The autonomous mobile robot system according to claim 1 , wherein the main sensor is a 2D-LiDAR (light detection and ranging).

3. The autonomous mobile robot system according to claim 2 , wherein the at least one type of sub-sensor includes an ultrasonic sensor, and the unique area is a dead end or a narrow section of a road.

4. The autonomous mobile robot system according to claim 2 , wherein the at least one type of sub-sensor includes a 3D sensor, and the unique region is a location that may receive reflected light and ambient light.

5. The autonomous mobile robot system according to claim 1 , wherein the at least one type of sub-sensor is stopped to notify the robot that it is continuing to travel.

Images