JP2020166422A - Autonomous mobile robot - Google Patents

Abstract

To achieve an autonomous mobile robot capable of moving at a moving speed without colliding with an obstacle even if manually designated to move.SOLUTION: An autonomous mobile robot (10) which automatically circling around on a floor includes a sensor (13) for sensing a distance to an obstacle existing in a traveling direction of the autonomous mobile robot (10), and a controller (11) for controlling the autonomous mobile robot (10) with reference to an output signal of the sensor (13). The controller (11) executes processing for determining an upper limit speed corresponding to the distance to the obstacle with reference to the output signal of the sensor (13), and processing for controlling a travel speed of the autonomous mobile robot (10) at the upper limit speed or low in a manual mode that travels according to a user operation.SELECTED DRAWING: Figure 1

Description

The present invention relates to an autonomous mobile robot.

In facilities such as medical facilities and long-term care facilities, many staff members come and go in the facility during the daytime, and it is possible for the staff members to quickly find the target person who has a problem in the facility. On the other hand, at night, the staff in charge of night duty patrols the facility at regular intervals to try to find problems.

In order to make up for this situation, a system has been adopted in which a camera is installed at a predetermined position in the facility and the image (still image or moving image) captured by the camera is transferred to the living room where the staff is waiting. There is.

However, in the above-mentioned system, it is difficult to detect the target person in the blind spot of the camera by an image. For example, if the patrol time interval of the staff in charge of night duty is one hour, it may be one hour later to find the subject who has fallen or wandered in the blind spot of the camera immediately after the patrol.

In order to improve this situation, an autonomous mobile robot that automatically patrols the facility can be used. When an autonomous mobile robot that automatically patrols detects an obstacle in the patrol route, it is desired that the robot safely avoids the obstacle without colliding with the obstacle. In addition, even when the staff manually specifies the traveling direction and speed for the autonomous mobile robot, it is required to safely avoid the robot without colliding with an obstacle.

The present invention has been made in view of the above problems, and an object of the present invention is to be able to move at a moving speed that does not collide with an obstacle even when the operation is manually specified. It is to realize an autonomous mobile robot.

In order to solve the above problems, the autonomous mobile robot according to the first aspect of the present invention is an autonomous mobile robot that automatically patrols on the floor, and the distance to an obstacle existing in the traveling direction of the autonomous mobile robot is determined. A sensor for detecting and a controller for controlling the autonomous mobile robot by referring to the output signal of the sensor are provided, and the controller refers to the output signal of the sensor and responds to the distance to the obstacle. It is configured to execute a process of determining the upper limit speed and a process of controlling the running speed of the autonomous mobile robot to be equal to or lower than the upper limit speed in the manual mode of traveling according to the user operation.

According to the above configuration, it is possible to realize an autonomous mobile robot capable of traveling at a speed limited to a distance to an obstacle even while traveling according to a user's request (traveling in a manual mode). it can.

According to the second aspect of the present invention, in the first aspect, the controller has a force for the user to advance the autonomous mobile robot in the manual mode, and the user rotates the autonomous mobile robot. It may be configured to determine at least one of the moving directions and speeds of the autonomous mobile robot according to at least one of the forces to be made.

According to the above configuration, the mode of the manual mode can be determined according to the force applied by the user.

In the autonomous mobile robot according to the third aspect of the present invention, in the above aspect 1 or 2, the upper limit speed is obtained by adding a predetermined distance to the braking distance according to the traveling speed of the autonomous mobile robot traveling on the floor. It is a speed at which the robot stops at a safe stop distance, and when the distance from the autonomous mobile robot running to the obstacle is equal to or less than the safe stop distance, the controller sets the traveling speed of the autonomous mobile robot to the upper limit speed. It may be configured to execute the process to be controlled below.

According to the above configuration, it is possible to realize an autonomous mobile robot that safely executes traveling to avoid obstacles by traveling at a speed in which the distance to an obstacle is longer than the safe stop distance.

In the above aspect 3, the autonomous mobile robot according to the fourth aspect of the present invention executes a command for controlling the traveling speed of the autonomous mobile robot to be equal to or lower than the upper limit speed after the sensor detects the obstacle. The sum of the idling distance traveled by the autonomous mobile robot and the braking distance may be shorter than the safe stop distance.

According to the above configuration, by setting a predetermined distance longer than the free running distance, a safety margin is secured, and it is possible to realize an autonomous mobile robot that safely executes running avoiding obstacles.

The autonomous mobile robot according to the fifth aspect of the present invention has the autonomous movement in any one of the above aspects 1 to 4 in the automatic mode in which the controller travels according to a patrol route set independently of the user operation. The robot may be configured to execute a process of controlling the traveling speed of the robot to be equal to or lower than the upper limit speed.

According to the above configuration, it is possible to realize an autonomous mobile robot capable of traveling at a speed limited to a speed according to the distance to an obstacle even in the automatic patrol mode.

In any one of the above aspects 1 to 5, the autonomous mobile robot according to the sixth aspect of the present invention has the controller according to at least one input interface for acquiring the output signal of the sensor and a predetermined program. It may be configured to include at least one processor that executes each of the above processes and at least one memory that stores the program.

According to the above configuration, the processor executes the process by referring to the information stored in the memory, so that the vehicle can travel at a speed limited to the distance to the obstacle even while traveling in the manual mode. It is possible to realize a possible autonomous mobile robot.

The control method according to the seventh aspect of the present invention is a control method for controlling an autonomous mobile robot that automatically patrols on the floor, and uses a sensor that detects a distance to an obstacle existing in the traveling direction of the autonomous mobile robot. The step of detecting the distance to the obstacle and the step of controlling the autonomous mobile robot by referring to the output signal of the sensor are included, and the step of controlling the robot refers to the output signal of the sensor. A method including a process of determining an upper limit speed according to the distance to the obstacle and a process of controlling the traveling speed of the autonomous mobile robot to be equal to or lower than the upper limit speed in a manual mode in which the robot travels according to a user operation. Is.

According to the above method, the same effect as that of the autonomous mobile robot is obtained.

The control program for controlling the autonomous mobile robot according to the eighth aspect of the present invention is the control program for controlling the autonomous mobile robot according to any one of the above aspects 1 to 6, and the controller is subjected to each of the above processes. It may be configured to be executed.

According to the above configuration, the same effect as that of the control method is obtained.

According to the present invention, according to the above configuration, autonomous movement capable of traveling limited to a speed according to the distance to an obstacle even during traveling according to a user's request (traveling in a manual mode). It has the effect of being able to realize a robot.

It is the schematic which shows typically the main structure which the autonomous mobile robot which concerns on one Embodiment of this invention has. It is the schematic which shows typically the main hardware composition provided with the autonomous mobile robot which concerns on one Embodiment of this invention. It is a perspective view which shows typically the state that the autonomous mobile robot which concerns on one Embodiment of this invention is looking around the facility. It is a schematic plan view which shows typically the state of mapping the obstacle detected by the range sensor. It is a flowchart which shows the timing which applies the speed limit. This is an example of a graph showing the relationship between the moving speed of an autonomous mobile robot and the braking distance. This is an example of a graph showing the relationship for deriving the speed limit of an autonomous mobile robot.

The autonomous mobile robot 10 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. The autonomous mobile robot 10 is an autonomous mobile robot for nursing care that performs a tour of the facility on behalf of staff of medical facilities and nursing facilities, and is a self-propelled autonomous movement capable of detecting obstacles in the course. It is a robot.

(Main configuration of autonomous mobile robot 10)
FIG. 1 is a block diagram showing a main hardware configuration 1 of the autonomous mobile robot 10. As shown in FIG. 1, the autonomous mobile robot 10 includes at least a controller 11, a force sensor 12, a range sensor 13, and a drive device 14. In another preferred embodiment, the autonomous mobile robot 10 can further include a contact sensor, a stop signal input interface, and an encoder (not shown).

The controller 11 has a route information generation unit 15, a determination unit 16, an output control unit 17, and a map information input unit 18 as main configurations. In FIG. 1, the controller 11 is functionally shown by using a functional block diagram, but in FIG. 2, the hardware configuration of the controller 11 is shown.

(Hardware configuration of controller)
FIG. 2 is a schematic view schematically showing a main hardware configuration included in the autonomous mobile robot 10 according to the embodiment of the present invention. As shown in FIG. 2, the autonomous mobile robot 10 has at least one controller 110. A plurality of controllers 110 may be provided depending on the target of information processing.

For example, a first controller 110a that processes information about the force sensor 12, a second controller 110b that processes information about the range sensor 13, and a third controller 110c that processes information about the drive device 14. The control may be shared by a plurality of controllers.

The program that executes the algorithm that executes the processing of the information input from the input interface 113 is stored in the memory 112. By executing the program stored in the memory 112 on the processor 111, the input information can be processed. The processed information is output from the output interface 114 as output information. The drive device 14 can be controlled by the information output from the output interface 114.

The map information is preferably input to the map information input unit 18 via the input interface 113, but the map information generated by the processor 111 can also be input. The route information generation unit 15, the determination unit 16, and the map information input unit 18 are preferably executed by the processor 111 as functions.

(Implementation mode of autonomous mobile robot 10)
FIG. 3 is a perspective view schematically showing how the autonomous mobile robot 10 according to the embodiment of the present invention is looking around the facility. FIG. 3 schematically shows how the autonomous mobile robot 10 detects the facility user P lying on the floor.

As shown in FIG. 3, the autonomous mobile robot 10 is mounted on the floor of the facility. The autonomous mobile robot 10 can self-propell in the facility by using the drive device 14.

In FIG. 3, the plane along the surface of the floor is defined as the xy plane, and the direction from the surface to the zenith among the normal directions of the surface of the floor is defined as the z-axis positive direction. Further, as shown in FIG. 3, the forward direction of the autonomous mobile robot 10 is defined as the x-axis positive direction. Further, among the directions included in the xy plane, the direction forming the right-handed Cartesian coordinate system together with the above-mentioned x-axis positive direction and z-axis positive direction is defined as the y-axis positive direction.

The housing of the autonomous mobile robot 10 includes a range sensor 13, and the exterior of the housing can be used as a contact sensor. In the autonomous mobile robot 10 illustrated in FIG. 3, it is preferable to provide the force sensor 12 at the upper end of the housing, but the specific location is not shown, and the other hardware is not shown. Further, the illustration of the internal structure of the housing of the autonomous mobile robot 10 is also omitted.

The range sensor 13 can be arranged at an arbitrary position in the housing of the autonomous mobile robot 10, but it is preferably arranged in front of the autonomous mobile robot 10 in the forward direction. The contact sensors are preferably arranged at a plurality of locations on the surface of the housing of the autonomous mobile robot 10.

An embodiment in which the autonomous mobile robot 10 having the above-described configuration can travel at a safe speed without colliding with an obstacle will be described below. First, the speed limit in the automatic patrol mode will be described, and then the speed limit in the manual mode will be described. The switching between the automatic patrol mode and the manual mode, and the timing of applying the speed limit will be described with reference to FIG. 5 as appropriate. Regarding the speed limit in the manual mode, the same phenomenon as the speed limit in the automatic patrol mode will not be described.

(Automatic patrol mode)
As shown in FIG. 1, the controller 11 has at least a map information input unit 18, a route information generation unit 15, and an output control unit 17.

The map information in the facility, which will be described later, is acquired via the map information input unit 18. The route information generation unit 15 generates rough route information in which the autonomous mobile robot 10 patrolls in the facility based on the current position information in the facility of the autonomous mobile robot 10 and the map information. The route information generation unit 15 further generates more detailed route information based on the obstacle information detected by the range sensor 13.

It is preferable that various processes are executed by the processor 111, and a program that defines various information and algorithms for executing the processes is stored in the memory 112.

Based on the route information generated by the route information generation unit 15 as described above, the output control unit 17 calculates the moving speed of the automatic patrol mode (S21 in FIG. 5).

The output interface 114 outputs output information corresponding to the generated route information to the drive device 14. The autonomous mobile robot 10 patrols by driving the drive device 14 based on the output information. As will be described later, the encoder (not shown) generates mileage information and movement direction information of the autonomous mobile robot 10 based on the amount of movement of the drive device 14 for the autonomous mobile robot 10 to patrol the facility. To do. The controller 11 generates the position information of the autonomous mobile robot 10 based on the information of the mileage and the moving direction generated by the encoder.

(Map information)
As described above, the map information in the facility is acquired via the map information input unit 18. In the present invention, the map information refers to a map that simplifies the floor information in the facility.

In a preferred embodiment, the generation of a movement route combining the movement direction information can be artificially set, but the movement block route is automatically set by an algorithm that generates the shortest route by setting a target point. You can also. The map information generated in this way is input via the map information input unit 18.

(Obstacle detection by range sensor)
The autonomous mobile robot 10 detects obstacles in the facility by the range sensor 13 while patrolling. As described above, the range sensor 13 can be arranged at an arbitrary position in the housing of the autonomous mobile robot 10, but it is preferable that the range sensor 13 is arranged so as to be able to measure a horizontal plane having a height of about 35 cm from the floor. As the range sensor 13, for example, a laser type range sensor such as UST-10LX manufactured by Hokuyo Electric Co., Ltd. can be adopted. Even when the autonomous mobile robot 10 is not patrolling, the range sensor 13 can detect an obstacle in the facility.

FIG. 4 schematically shows how an obstacle in the facility is detected by the range sensor 13. FIG. 4 is a plan view of the floor surface from the positive direction of the z-axis. At a height of +35 cm in the z-axis direction from the floor surface, the origin is the position of the range sensor 13 mounted on the housing of the autonomous mobile robot 10, the forward direction of the autonomous mobile robot 10 is the x-axis, and the plane direction is The direction orthogonal to the x-axis was defined as the y-axis. In FIG. 4, obstacles are indicated by small circles. As shown in FIG. 4, the scanning angle of the range sensor 13 is shown by ± θ °. In a preferred embodiment, the range sensor 13 detects an obstacle in the range of ± θ = ± 115 degrees. Further, the range sensor 13 preferably has a detection distance of about 0.06 m to 10 m. The scanning time of the range sensor 13 is preferably 25 ms. The angular resolution of the range sensor 13 is preferably 0.25 degrees. Without being limited to these values, the range sensor 13 can have any detection distance, scanning angle, scanning time, and angular resolution.

(Speed limit)
As described above, the output control unit 17 calculates the moving speed of the automatic patrol mode based on the route information generated by the route information generation unit 15 (S21 in FIG. 5). FIG. 5 is a flowchart showing the timing of applying the speed limit. When the force sensor 12 is not effective (No in S23), the output control unit 17 controls the drive device 14 via the output interface 114 with the above-calculated movement speed as the command speed of the automatic patrol mode.

While the autonomous mobile robot 10 is patrolling at the movement speed calculated in this way, an obstacle in the facility is detected by the range sensor 13, and the distance between the detected obstacle and the autonomous mobile robot 10 is a predetermined distance. When it becomes shorter than, the output control unit 17 executes the limitation of the traveling speed.

(Relationship between running speed and braking distance)
Generate speed limit parameters in advance to implement speed limit. In the present invention, the speed limit parameter is a parameter that determines the upper speed limit according to the distance to the obstacle. As will be described later, the controller 11 refers to the output signal of the range sensor 13, and applies the speed limit parameter to the upper limit speed according to the distance from the output signal of the range sensor 13 to the obstacle. To determine.

It is preferable that various processes are executed by the processor 111, and a program that defines various information and algorithms for executing the processes is stored in the memory 112.

FIG. 6 is an example of a graph showing the relationship between the moving speed and the braking distance when the autonomous moving robot 10 is run on a certain floor. The relationship between the moving speed and the braking distance can be measured on any floor, but it is preferable to measure on a hard floor having a small coefficient of friction. From the viewpoint of ensuring a safety margin that does not collide with obstacles, it is preferable to use the speed limit parameters obtained on the floor having a small friction coefficient on other floors as well.

The horizontal axis of the graph of FIG. 6 is the traveling speed of the autonomous mobile robot 10 traveling on the floor, and the vertical axis represents the braking distance. In FIG. 6, a stop command is executed by the autonomous mobile robot 10 traveling on the floor, and the distance (braking distance) from the position at the time of the stop command to the position where the autonomous mobile robot 10 actually stops is measured for each traveling speed. The measured values are indicated by ○. From the measured values in FIG. 6, it can be confirmed that the braking distance increases as the traveling speed increases.

FIG. 7 is a graph in which the horizontal axis is the braking distance and the vertical axis is the traveling speed with respect to the measurement result of FIG. Multiple regression analysis is performed on the relationship shown in FIG. In a preferred embodiment, multiple regression analysis of the polynomial is performed by the least squares method. In this embodiment, the result of performing multiple regression analysis by the least squares method using a quadratic function is shown by a broken line (see FIG. 7).

When the stop command is executed, the autonomous mobile robot 10 traveling on the floor at the speed of the broken line indicated by the quadratic function then travels a braking distance and comes into contact with an obstacle when stopped. In this embodiment, the broken line showing the result of performing the multiple regression analysis by the least squares method using the quadratic function is referred to as a collision velocity curve. In the present invention, a variable that secures a predetermined safety margin with respect to the collision speed curve is referred to as a speed limit parameter. The safety margin can be arbitrarily set according to the free running distance and the like, but in the example shown in FIG. 7, the safety margin is uniformly set to 200 mm regardless of the speed. In FIG. 7, the speed limit parameter is shown by a solid line shifted in the positive direction of the x-axis by 200 mm from the broken line showing the collision speed curve. By determining the speed limit parameter in this way, it can be applied as a function for determining the upper limit speed according to the distance to the obstacle.

(Relationship between running speed, free running distance and safety margin)
As described above, the range sensor 13 mounted on the autonomous mobile robot 10 traveling on the floor at a predetermined traveling speed detects an obstacle in the facility, and the output control unit 17 applies the speed limit parameter. To determine the upper speed limit. The scanning time of the range sensor 13 (for example, 25 ms), the clock frequency of the processor 111 of the second controller 110b that controls the range sensor 13, and the speed limit parameter generated by the output control unit 17 are applied to the drive device 14. Due to the superposition relationship such as the clock frequency of the processor 111 of the third controller 110c, there is a time lag between the time when the range sensor 13 detects an obstacle and the time when the drive device 14 actually executes the speed limit command. .. In the present embodiment, the distance traveled by the autonomous mobile robot 10 during this time lag is referred to as a free running distance. Further, the sum of the free running distance and the braking distance is referred to as a stop distance in the present embodiment. The sum of the braking distance and the safety margin is referred to as a safe stop distance in this embodiment.

The safety margin is preferably set longer than the free running distance at the maximum speed of the autonomous mobile robot 10. As a result, the safe stop distance, which is the sum of the braking distance and the safety margin, is longer than the stop distance, which is the sum of the free running distance and the braking distance. Therefore, the upper limit speed is a speed at which the autonomous mobile robot 10 traveling on the floor stops at a shorter distance than the safe stop distance according to the traveling speed.

In a preferred embodiment, a collision speed curve is generated for each floor of the facility in which the autonomous mobile robot 10 is used, and a safety margin is obtained from the free running distance due to a time lag of the range sensor 13 and the controller 11 mounted on the autonomous mobile robot 10. Is determined, and a speed limit parameter can be generated for each floor by adding a safety margin to the collision speed curve. It is preferable to carry out an experiment for obtaining the braking distance as in the example shown in FIG. 6 in advance for each floor, and store the speed limit parameter in the memory 112 in advance via the input interface 113.

As a result, when the autonomous mobile robot 10 travels on the floor and the range sensor 13 detects an obstacle, the controller 11 refers to the speed limit parameter. When the distance to the obstacle is shorter than the safe stop distance, the output control unit 17 controls the drive device 14 so as to reduce the speed to the speed limit or less according to the referenced speed limit parameter.

(Speed limit in automatic patrol mode)
In this way, when the autonomous mobile robot 10 patrols and detects an obstacle in the facility by the range sensor 13, and the distance between the detected obstacle and the autonomous mobile robot 10 becomes shorter than a predetermined distance. , The output control unit 17 executes the limitation of the traveling speed (S26).

(Manual mode)
As shown in FIG. 3, the autonomous mobile robot 10 has a substantially columnar shape in which the upper end thereof is rounded into a hemisphere. The force sensor 12 can be arranged at the upper end portion rounded to a hemisphere. In order to transmit the force to the force sensor 12 more accurately, it is also preferable to arrange a lever (not shown) connected to the force sensor 12 at the upper end of the autonomous mobile robot 10. The force sensor 12 senses the force urged to the upper end portion, and the determination unit 16 determines the force urged from the outside as an input signal.

In the present embodiment, the force sensor 12 is arranged at the upper end of the autonomous mobile robot 10, but the arrangement location is not limited to the upper end, and the autonomous mobile robot 10 can be located at any place where an external force can be detected. Can be placed anywhere in.

The staff of the facility can change the moving speed and moving direction of the autonomous moving robot 10 by urging the upper end of the autonomous moving robot 10. In a preferred embodiment, the staff can stand beside the autonomous mobile robot 10 and urge the force sensor 12 located at the upper end of the autonomous mobile robot 10. In this case, the force urged by a human hand such as an employee in the traveling direction of the autonomous mobile robot 10 with respect to the force sensor 12, and the force applied by a human hand such as an employee from around the central axis of the autonomous mobile robot 10 in the z-axis direction. The determination unit 16 of the controller 11 determines the magnitude of the rotational moment as an input signal.

The route information generation unit 15 of the controller 11 calculates the movement speed and / or the movement direction in the manual mode based on the magnitude of the input signal determined by the determination unit 16, and the movement direction information and the movement speed are supplied to the output interface 114. Output information.

Based on the route information generated by the route information generation unit 15 as described above, the output control unit 17 calculates the movement speed in the manual mode (S22 in FIG. 5).

As in the case of the automatic patrol mode, the output control unit 17 outputs the output information corresponding to the generated route information to the drive device 14 via the output interface 114. The encoder generates mileage information and movement direction information of the autonomous mobile robot 10 based on the movement amount of the drive device 14 in the manual mode of the autonomous mobile robot 10. The controller 11 generates the position information of the autonomous mobile robot 10 based on the information of the mileage and the moving direction generated by the encoder.

(Switching between automatic patrol mode and manual mode)
The mode of switching to the manual mode when the autonomous mobile robot 10 is autonomously moving toward a predetermined target in the above-mentioned automatic patrol mode will be described below.

FIG. 5 is a flowchart showing a method of switching between the automatic patrol mode and the manual mode for drive control.

The route information generation unit 15 generates the patrol route information in the automatic patrol mode based on the map information input via the map information input unit 18, the obstacle information detected by the range sensor 13, and the current position information. To do. Based on the generated patrol route in the automatic patrol mode, the route information generation unit 15 calculates the movement speed in the automatic patrol mode (S21).

As described above, when the autonomous mobile robot 10 is autonomously moving toward a predetermined target in the automatic patrol mode, it is based on the magnitude of the force urged by the force sensor 12 at regular intervals. The route information generation unit 15 calculates the movement speed in the manual mode (S22).

The force urged by the staff in the direction of travel of the autonomous mobile robot 10 and the rotational moment urged by the staff from around the central axis in the z-axis direction of the autonomous mobile robot 10 with respect to the force sensor 12. The determination unit 16 determines the threshold value using the magnitude of and as an input signal. The threshold value can be arbitrarily set in advance. When the input signal is larger than the threshold value, the force sensor 12 is determined to be effective (YES in S23). If the input signal is smaller than the threshold value, the force sensor 12 is not determined to be valid (NO in S23).

When the force sensor 12 is not determined to be valid (NO in S23), the output interface 114 calculates the moving speed in the automatic patrol mode as the motor command speed (S24). When the force sensor 12 is determined to be effective (YES in S23), the output interface 114 calculates the moving speed in the manual mode as the motor command speed (S25).

(Speed limit in manual mode)
In the manual mode as well, as in the automatic patrol mode described above, the autonomous mobile robot 10 detects an obstacle in the facility by the range sensor 13 while traveling in the manual mode, and the detected obstacle and the autonomous mobile robot 10 When the distance between them becomes shorter than a predetermined distance, the output control unit 17 executes the limitation of the traveling speed (S26).

Even when the distance between the detected obstacle and the autonomous mobile robot 10 becomes shorter than the predetermined distance, the speed limit is higher than the speed limit determined by the output control unit 17 with reference to the speed limit parameter by the controller 11. If the traveling speed in the manual mode is slower, the traveling speed in the manual mode is prioritized without increasing the speed to the speed limit determined by the output control unit 17.

Further, an obstacle is detected by the range sensor 13 during the automatic patrol mode, the speed limit in the automatic patrol mode is executed by the output control unit 17, and the manual mode is applied via the force sensor 12 during the speed limit running. If so, the output control unit 17 determines to prioritize the traveling speed at the indicated speed urged in the manual mode.

However, since the traveling is switched to the manual mode, the output control unit 17 compares the indicated speed urged in the manual mode with the speed limit speed. If the indicated speed urged in the manual mode is slower than the speed limit determined with reference to the speed limit parameter, the output control unit 17 determines the traveling speed at the urged indicated speed in the manual mode. Make a priority decision. On the other hand, when the speed limit is slower than the indicated speed urged in the manual mode, the output control unit 17 is determined by referring to the speed limit parameter than the indicated speed urged in the manual mode. Make a decision to prioritize the running speed at the speed limit.

(Acceleration limit)
As described above, the speed limits in the automatic patrol mode and the manual mode have been described, but the signals instructing these speed limits are input discretely from the individual sensors. In addition, noise from the force sensor 12 is often included, such as when the automatic patrol mode and the manual mode are suddenly switched. Further, even after the speed is limited, when the change in speed with respect to the time change is examined, the speed waveform may be rectangular with respect to the time axis.

When the motor of the drive device 14 is operated by speed switching based on such discrete instruction signals, the traveling mode of the autonomous mobile robot 10 becomes awkward.

In order to realize a smooth velocity change, it is preferable to limit the velocity with an appropriate acceleration and convert the velocity waveform into a continuous wave velocity waveform instead of a rectangular velocity waveform with respect to the time axis (S27).

(Motor drive)
The output control unit 17 converts (D / A conversion) the speed limit information (digital signal) that has been subjected to the acceleration limitation (S27) processing as described above into an analog signal (S28). The motor driver is controlled by the speed limit information of the D / A converted analog signal and output to the drive device 14, and the motor (not shown) is rotated (S29).

(Current location information)
In the preferred drive device 14, motors for driving the left and right independent wheels can be arranged on each wheel. Each motor can be equipped with an encoder (not shown) that detects the number of rotations of the rotation shaft of the motor. Based on the number of rotations of the rotation axes of the left and right motors, the encoder generates mileage information and movement direction information of the autonomous mobile robot 10. The position information generation unit generates the position information of the autonomous mobile robot 10 based on the information of the mileage and the movement direction generated by the encoder. The position information generation process is repeated at regular intervals to update the current position of the autonomous mobile robot 10.

(Stopping action by contact sensor)
As described above, one or more contact sensors can be mounted on the surface of the housing of the autonomous mobile robot 10. When the contact sensor on the surface of the housing of the autonomous mobile robot 10 detects a reaction, the controller 11 outputs a stop signal to the output control unit 17 to stop the drive device 14.

The control for stopping the drive device 14 by the contact sensor is preferably executed in preference to the speed limit control described above.

[Example of realization by software]
The controller 11 of the autonomous mobile robot 10 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the autonomous mobile robot 10 includes a computer that executes instructions of a program that is software that realizes each function. The computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, in addition to a "non-temporary tangible medium" such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

10 Autonomous mobile robot 11 Controller 12 Force sensor 13 Range sensor 14 Drive device 15 Path information generation unit 16 Judgment unit 17 Output control unit 18 Map information input unit 110a First controller 110b Second controller 110c Third controller 111 Processor 112 Memory 113 Input interface 114 Output interface

Claims (8)

An autonomous mobile robot that automatically patrols the floor
A sensor that detects the distance to an obstacle in the direction of travel of the autonomous mobile robot,
A controller that controls the autonomous mobile robot with reference to the output signal of the sensor is provided.
The controller
The process of determining the upper limit speed according to the distance to the obstacle with reference to the output signal of the sensor, and
An autonomous mobile robot characterized by executing a process of controlling the traveling speed of the autonomous mobile robot to be equal to or lower than the upper limit speed in a manual mode in which the robot travels according to a user operation. In the manual mode, the controller moves the autonomous mobile robot according to at least one of a force by which the user advances the autonomous mobile robot and a force by which the user rotates the autonomous mobile robot. Determine at least one of direction and speed,
The autonomous mobile robot according to claim 1, wherein the robot is characterized by the above. The upper limit speed is a speed at which the robot stops at a safe stop distance obtained by adding a predetermined distance to the braking distance corresponding to the traveling speed of the autonomous mobile robot traveling on the floor.
The controller
When the distance from the autonomous mobile robot while traveling to the obstacle is equal to or less than the safe stop distance, a process for controlling the traveling speed of the autonomous mobile robot to the upper limit speed or less is executed. Item 2. The autonomous mobile robot according to Item 1 or 2. The free running distance and the braking distance that the autonomous mobile robot travels between the time when the sensor detects the obstacle and the time when the command for controlling the traveling speed of the autonomous mobile robot is executed to be equal to or lower than the upper limit speed are executed. The autonomous mobile robot according to claim 3, wherein the sum with and is shorter than the safe stopping distance. The controller executes a process of controlling the traveling speed of the autonomous mobile robot to be equal to or lower than the upper limit speed in an automatic mode in which the robot travels according to a patrol route set independently of the user operation.
The autonomous mobile robot according to any one of claims 1 to 4, wherein the robot is characterized by the above. The controller
With at least one input interface that acquires the output signal of the sensor,
At least one processor that executes each of the above processes according to a predetermined program, and
It comprises at least one memory that stores the program.
The autonomous mobile robot according to any one of claims 1 to 5, wherein the robot is characterized by the above. It is a control method that controls an autonomous mobile robot that automatically patrols on the floor.
A process of detecting the distance to the obstacle by using a sensor that detects the distance to the obstacle existing in the traveling direction of the autonomous mobile robot, and
A step of controlling the autonomous mobile robot with reference to the output signal of the sensor is provided.
The control step is
The process of determining the upper limit speed according to the distance to the obstacle with reference to the output signal of the sensor, and
A control method comprising a process of controlling the traveling speed of the autonomous mobile robot to or less than the upper limit speed in a manual mode of traveling according to a user operation. A control program for controlling an autonomous mobile robot according to any one of claims 1 to 6, wherein the controller executes each of the above processes.

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