Autonomous traveling device

Abstract

To provide an autonomous traveling device that is able to detect a collision of an object in all directions at a low cost.SOLUTION: An autonomous traveling device (1), which is an autonomous traveling device that autonomously travels on a traveling surface, includes: an acceleration sensor (10) for measuring an acceleration of the autonomous traveling device; and a collision detection unit (31) that detects a collision of the autonomous traveling device with an object. The collision detection unit detects the collision, based on an amount of change per unit time of the acceleration in a direction parallel to the traveling surface, measured by the acceleration sensor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an autonomous driving device. [Background technology]

[0002] An autonomous mobile device that autonomously travels to perform cleaning, etc. is known as conventional technology. In particular, examples of an autonomous mobile device that can detect collisions with objects in all directions are disclosed in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2003-280740 [Patent Document 2] Patent Publication No. 2010-49577 Summary of the Invention [Problem to be solved by the invention]

[0004] The devices disclosed in Patent Documents 1 and 2 have a problem in that the structure for detecting contact with an object is complicated, which significantly increases the cost of the autonomous driving device.

[0005] An object of one aspect of the present invention is to realize an autonomous driving device that can detect collisions with objects in all directions at low cost. [Means for solving the problem]

[0006] In order to solve the above problem, an autonomous driving device according to one embodiment of the present invention is an autonomous driving device that autonomously drives on a driving surface, and is equipped with an acceleration sensor for measuring the acceleration of the autonomous driving device, and a collision detection unit that detects a collision of the autonomous driving device with an object, and the collision detection unit detects the collision based on the amount of change per unit time in acceleration in a direction parallel to the driving surface measured by the acceleration sensor. [Effects of the Invention]

[0007] According to one aspect of the present invention, an autonomous driving device that can detect collisions with objects in all directions can be realized at low cost. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing the configuration of a main part of an autonomous driving device according to a first embodiment. [Figure 2] 5 is a flowchart illustrating an example of a process in which a collision detection unit detects a collision in the autonomous mobile device according to the first embodiment. [Figure 3] FIG. 10 is a block diagram showing the configuration of a main part of an autonomous driving device according to a second embodiment. [Figure 4] FIG. 10 is a block diagram showing the configuration of a main part of an autonomous driving device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0010] (Configuration of autonomous driving device) FIG. 1 is a block diagram showing the configuration of the main parts of an autonomous mobile device 1. The autonomous mobile device 1 autonomously travels on a traveling surface. Specifically, the autonomous mobile device 1 may be a robot vacuum cleaner that cleans the traveling surface. The traveling surface may be, for example, the floor of a building, but is not limited to this. As shown in FIG. 1, the autonomous mobile device 1 includes an acceleration sensor 10, a motor 20, traveling wheels 25, a control unit 30, and a memory unit 40.

[0011] The autonomous mobile device 1 also includes components common to autonomous mobile devices, such as a bumper for protecting the device from impacts due to collisions with objects, and a distance sensor for measuring the distance to surrounding objects. The distance sensor may be, for example, a LIDAR (Laser Image Detection And Ranging) or a 3D camera.

[0012] Furthermore, when the autonomous mobile device 1 is a robot vacuum cleaner, the autonomous mobile device 1 has a cleaning function. Furthermore, the autonomous mobile device 1 preferably has a position identification function such as a global positioning system (GPS), simultaneous localization and mapping (SLAM), or odometry (an encoder provided on the running wheels 25) to identify its own position.

[0013] The acceleration sensor 10 is a sensor for measuring the acceleration of the autonomous mobile device 1. The acceleration sensor 10 may be a so-called IMU (Inertial Measurement Unit). The acceleration sensor 10 can measure acceleration in both directions parallel to and perpendicular to the traveling surface.

[0014] Running wheels 25 are wheels that cause autonomous mobile device 1 to travel on a traveling surface. Motor 20 is a traction motor that drives running wheels 25. Running wheels 25 rotate due to the driving force transmitted from motor 20 to running wheels 25, causing autonomous mobile device 1 to travel on a traveling surface.

[0015] The control unit 30 controls the operation of the autonomous mobile device 1. As shown in Fig. 1, the control unit 30 includes a collision detection unit 31 and a travel control unit 32. The control unit 30 also performs control similar to that of a general autonomous mobile device, such as detecting surrounding objects using a distance sensor.

[0016] The collision detection unit 31 detects a collision of the autonomous mobile device 1 with an object. In the first embodiment, the collision detection unit 31 detects a collision of the autonomous mobile device 1 with an object based on the amount of change per unit time in acceleration in a direction parallel to the traveling surface, measured by the acceleration sensor 10.

[0017] When the autonomous mobile device 1 collides with an object, the acceleration of the autonomous mobile device 1 in a direction parallel to the traveling surface changes suddenly. The collision detection unit 31 detects a collision of the autonomous mobile device 1 with the object when the absolute value of the change in acceleration per unit time measured by the acceleration sensor 10 is significantly larger than the value when the autonomous mobile device 1 does not collide with the object.

[0018] Specifically, the autonomous mobile device 1 may have a threshold set to determine whether the absolute value of the amount of change in acceleration per unit time is significantly greater than the value when the autonomous mobile device 1 is not colliding with an object. The threshold may be set taking into consideration the weight of the autonomous mobile device 1, the expected traveling speed, and the like. The collision detection unit 31 may detect a collision of the autonomous mobile device 1 with an object when the absolute value of the amount of change in acceleration per unit time is equal to or greater than the threshold.

[0019] The driving control unit 32 controls the speed and direction of driving of the autonomous driving device 1. Specifically, the driving control unit 32 controls the start and stop of rotation of the motor 20 and the rotation speed during rotation. The driving control unit 32 also controls the orientation of the running wheels 25.

[0020] When the collision detection unit 31 detects a collision, the driving control unit 32 may stop the driving of the autonomous mobile device 1. Furthermore, the driving control unit 32 may cause the autonomous mobile device 1 to drive a certain distance in the opposite direction to the direction in which the autonomous mobile device 1 was driving immediately before being stopped. The certain distance may be, for example, 10 cm, but is not limited to this.

[0021] Furthermore, the driving control unit 32 may turn the autonomous mobile device 1 so that the object that collided with the autonomous mobile device immediately before stopping is within the detection range of a distance sensor provided in the autonomous mobile device 1. Thereafter, the driving control unit 32 may cause the autonomous mobile device 1 to resume driving on a route that avoids the object that collided with the autonomous mobile device immediately before stopping. This allows the autonomous mobile device 1 to continue driving and cleaning, etc., even if it collides with an object.

[0022] The memory unit 40 is a storage device that stores information necessary for control by the control unit 30. For example, the memory unit 40 stores acceleration previously measured by the acceleration sensor 10, which is used by the collision detection unit 31 to calculate the amount of change in acceleration per unit time. However, the autonomous mobile device 1 does not necessarily need to include the memory unit 40. The autonomous mobile device 1 may be communicably connected to, for example, an external storage device that stores information necessary for control by the control unit 30.

[0023] (effect) The autonomous mobile device 1 detects surrounding objects using a distance sensor or the like, and travels in a manner that avoids collisions with the detected objects. However, it is difficult for a distance sensor to detect objects in all directions. For example, if the distance sensor is a LIDAR, the detection range is approximately 180° in front of the autonomous mobile device 1. In addition, a blind spot may be created in the detection range of the distance sensor due to a bumper or the like provided on the autonomous mobile device 1. For this reason, for example, when an object is detected by the distance sensor and the autonomous mobile device 1 changes direction to avoid the object, it may collide with another object that is located near the side of the autonomous mobile device 1 but has not been detected by the distance sensor.

[0024] In the autonomous mobile device 1, the collision detection unit 31 detects a collision of the autonomous mobile device 1 with an object based on the acceleration measured by the acceleration sensor 10. Therefore, even if the autonomous mobile device 1 collides with an object not detected by the distance sensor, for example, when changing direction, the collision can be detected, and the autonomous mobile device 1 can move away from the object to avoid a second collision. In other words, the autonomous mobile device 1 can detect collisions in all directions without using a mechanical bumper or the like.

[0025] (Control of autonomous driving devices) FIG. 2 is a flowchart showing an example of a process in which the collision detection unit 31 in the autonomous mobile device 1 detects a collision.

[0026] The collision detection unit 31 acquires a signal indicating the acceleration of the autonomous mobile device 1 from the acceleration sensor 10 (S1). Next, the collision detection unit 31 calculates the amount of change in the acceleration of the autonomous mobile device 1 (S2).

[0027] The collision detection unit 31 calculates whether the amount of change in acceleration calculated in step S2 is equal to or greater than a threshold value (S3). If the amount of change in acceleration is equal to or greater than the threshold value (YES in step S3), the collision detection unit 31 detects a collision of the autonomous mobile device 1 with an object (S4). Thereafter, the collision detection unit 31 ends the process. If the amount of change in acceleration is not equal to or greater than the threshold value (NO in step S3), the collision detection unit 31 ends the process without executing step S4. In other words, if the amount of change in acceleration is not equal to or greater than the threshold value, the collision detection unit 31 does not detect a collision of the autonomous mobile device 1 with an object.

[0028] The collision detection unit 31 executes a series of processes from steps S1 to S4 for each unit time, which may be, for example, 0.1 seconds, but is not limited to this.

[0029] (Prevents false detection when starting or stopping) The acceleration of the autonomous mobile device 1 varies not only due to a collision of the autonomous mobile device 1 with an object, but also due to control by the travel control unit 32. For example, if the autonomous mobile device 1 accelerates or decelerates suddenly when it starts or stops under the control of the travel control unit 32, the amount of change in acceleration may exceed the threshold value. For this reason, in the detection based solely on the amount of change in acceleration described above, the collision detection unit 31 may erroneously detect a collision when the autonomous mobile device 1 starts or stops under the control of the travel control unit 32.

[0030] The collision detection unit 31 does not need to detect a collision of the autonomous mobile device 1 with an object for a predetermined period of time from the time the driving control unit 32 starts or stops the autonomous mobile device 1. The predetermined period may be a period of time in which the impact on acceleration caused by the driving control unit 32 starting or stopping the autonomous mobile device 1 is considered to be sufficiently small. This reduces the possibility that the collision detection unit 31 will erroneously detect a collision of the autonomous mobile device 1 with an object when the driving control unit 32 starts or stops the autonomous mobile device 1.

[0031] (Prevents false detection on inclined surfaces or steps) The surface on which the autonomous mobile device 1 travels is not necessarily horizontal, and may include an inclined surface or a step that the autonomous mobile device 1 can overcome. When the autonomous mobile device 1 travels on such a surface, the amount of change in acceleration of the autonomous mobile device 1 may exceed the threshold value. For this reason, with the detection based solely on the amount of change in acceleration described above, the collision detection unit 31 may erroneously detect a collision of the autonomous mobile device 1 with an object when the autonomous mobile device 1 travels on an inclined surface or a surface that includes a step that the autonomous mobile device 1 can overcome.

[0032] The collision detection unit 31 may further detect a collision of the autonomous mobile device 1 with an object based on the acceleration in a direction perpendicular to the traveling surface measured by the acceleration sensor 10. When the autonomous mobile device 1 is traveling on an inclined surface or a step, the acceleration in the direction perpendicular to the traveling surface will be a different value from when the autonomous mobile device 1 is traveling on a horizontal traveling surface. Therefore, if the acceleration in the direction perpendicular to the traveling surface is significantly different from the value when the autonomous mobile device 1 is traveling on a horizontal traveling surface, the collision detection unit 31 may not detect a collision of the autonomous mobile device 1 with an object. This reduces the possibility that the collision detection unit 31 will erroneously detect a collision of the autonomous mobile device 1 with an object when the autonomous mobile device 1 is traveling on an inclined surface or a step.

[0033] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0034] Fig. 3 is a block diagram showing the configuration of the main parts of an autonomous mobile device 1A according to embodiment 2. As shown in Fig. 3, the autonomous mobile device 1A differs from the autonomous mobile device 1 in that it further includes a load sensor 50 and a control unit 30A instead of the control unit 30.

[0035] The load sensor 50 measures the load on the motor 20. The load sensor 50 may be, for example, an ammeter that measures the current value in the motor 20, or may be a sensor that measures other parameters related to the load on the motor 20.

[0036] Control unit 30A differs from control unit 30 in that it includes collision detection unit 31A instead of collision detection unit 31. Collision detection unit 31A uses the same process as collision detection unit 31 to detect a collision of autonomous mobile device 1 with an object based on the amount of change per unit time in acceleration in a direction parallel to the traveling surface measured by acceleration sensor 10. Collision detection unit 31A further detects a collision of autonomous mobile device 1A with an object based on the load on motor 20 measured by load sensor 50.

[0037] When the autonomous mobile device 1A collides with a soft object, the change in acceleration of the autonomous mobile device 1A per unit time is smaller than when the autonomous mobile device 1A collides with a hard object. In this case, the collision detection unit 31A may not be able to detect the collision of the autonomous mobile device 1A with the object based on the change in acceleration per unit time in the direction parallel to the traveling surface measured by the acceleration sensor 10.

[0038] When autonomous mobile device 1A collides with an object and its travel is interrupted, the load on motor 20 becomes larger compared to when travel is not interrupted, regardless of the hardness of the object. When the load on motor 20 measured by load sensor 50 is significantly larger compared to when travel is not interrupted, collision detection unit 31A detects the collision of autonomous mobile device 1A with an object, regardless of the acceleration measured by acceleration sensor 10. Therefore, collision detection unit 31A can detect the collision of autonomous mobile device 1A with an object, regardless of the hardness of the object with which autonomous mobile device 1A has collided.

[0039] Furthermore, when the traveling surface is inclined, the load on the motor 20 measured by the load sensor 50 may become large. The collision detection unit 31A may be configured not to detect a collision of the autonomous mobile device 1 with an object when the acceleration in the direction perpendicular to the traveling surface varies significantly compared to the value when traveling on a horizontal traveling surface.

[0040] [Embodiment 3] Fig. 4 is a block diagram showing the configuration of the main parts of an autonomous mobile device 1B according to embodiment 3. As shown in Fig. 4, autonomous mobile device 1B differs from autonomous mobile device 1A in that it includes control unit 30B instead of control unit 30A. Control unit 30B differs from control unit 30 in that it includes collision detection unit 31B instead of collision detection unit 31A, and in that it further includes attitude monitoring unit 33.

[0041] The attitude monitoring unit 33 monitors the attitude of the autonomous mobile device 1B based on the acceleration measured by the acceleration sensor. When a change occurs in the attitude of the autonomous mobile device 1B, the collision detection unit 31B detects a collision of the autonomous mobile device 1B with an object based on the acceleration of the autonomous mobile device 1B and the load on the motor 20, as described in the first and second embodiments.

[0042] When autonomous mobile device 1B collides with an object, there is a high possibility that a change will occur in the attitude of autonomous mobile device 1B. However, when a change occurs in the attitude of autonomous mobile device 1B, it is not necessarily caused by autonomous mobile device 1B colliding with an object, and it may also be caused by, for example, a change in the topography of the traveling surface.

[0043] In autonomous mobile device 1B, collision detection unit 31B detects a collision of autonomous mobile device 1B with an object when a change occurs in the attitude of autonomous mobile device 1B, based on the measurement results from acceleration sensor 10 and load sensor 50. In other words, when a change occurs in the attitude of autonomous mobile device 1B, collision detection unit 31B determines whether the change in attitude of autonomous mobile device 1B is due to a collision or a change in the topography of the traveling surface, based on the measurement results from acceleration sensor 10 and load sensor 50. This enables collision detection unit 31B to reduce the number of processes for detecting a collision of autonomous mobile device 1B with an object, and to detect collisions with high accuracy.

[0044] [Software implementation example] The functions of the autonomous driving devices 1, 1A, 1B (hereinafter referred to as "devices") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device (particularly each part included in the control units 30, 30A, 30B).

[0045] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program, thereby realizing the functions described in each of the above embodiments.

[0046] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0047] Furthermore, some or all of the functions of the control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of the control blocks can also be realized by, for example, a quantum computer.

[0048] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0049] 〔summary〕 The present invention can also be expressed as follows.

[0050] An autonomous driving device according to aspect 1 of the present invention is an autonomous driving device that autonomously drives on a driving surface, and is equipped with an acceleration sensor for measuring the acceleration of the autonomous driving device, and a collision detection unit for detecting a collision of the autonomous driving device with an object, and the collision detection unit detects the collision based on the amount of change per unit time in acceleration in a direction parallel to the driving surface measured by the acceleration sensor.

[0051] In addition, the autonomous driving device of aspect 2 of the present invention is the same as in aspect 1, and further includes a driving control unit that controls the driving of the autonomous driving device, and the collision detection unit does not detect the collision for a predetermined period of time from the time the driving control unit starts or stops the autonomous driving device.

[0052] Furthermore, in the autonomous driving device according to aspect 3 of the present invention, in aspect 1 or 2, the collision detection unit further detects the collision based on acceleration measured by the acceleration sensor in a direction perpendicular to the driving surface.

[0053] In addition, the autonomous driving device of aspect 4 of the present invention, in any of aspects 1 to 3, further includes a motor that drives running wheels that cause the autonomous driving device to run on the running surface, and a load sensor that measures the load on the motor, and the collision detection unit further detects the collision based on the magnitude of the load measured by the load sensor.

[0054] In addition, the autonomous driving device of aspect 5 of the present invention is, in aspect 1, further equipped with a motor that drives the running wheels that cause the autonomous driving device to run on the running surface, a load sensor that measures the load on the motor, and an attitude monitoring unit that monitors the attitude of the autonomous driving device based on the acceleration measured by the acceleration sensor, and the collision detection unit detects the collision based on the measurement results by the acceleration sensor and the load sensor when a change occurs in the attitude of the autonomous driving device.

[0055] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0056] 1, 1A, 1B Autonomous Driving Device 10 Acceleration Sensor 20 motors 25 Running wheels 31, 31A, 31B Collision detection unit 32 Driving control unit 33 Posture Monitoring Department 50 Load Sensor

Claims

1. An autonomous driving device that autonomously travels on a travel surface, an acceleration sensor for measuring the acceleration of the autonomous driving device; a collision detection unit that detects a collision of the autonomous driving device with an object, The collision detection unit detects the collision based on a change in acceleration per unit time in a direction parallel to the traveling surface measured by the acceleration sensor.

2. Further, a driving control unit is provided to control the driving of the autonomous driving device, The autonomous driving device according to claim 1 , wherein the collision detection unit does not detect the collision for a predetermined period of time from the time the driving control unit starts or stops the autonomous driving device.

3. The autonomous driving device according to claim 1 , wherein the collision detection unit further detects the collision based on acceleration measured by the acceleration sensor in a direction perpendicular to the driving surface.

4. a motor that drives running wheels that cause the autonomous driving device to travel on the travel surface; a load sensor for measuring a load on the motor; The autonomous driving device according to claim 1 , wherein the collision detection unit further detects the collision based on the magnitude of the load measured by the load sensor.

5. a motor that drives running wheels that cause the autonomous driving device to travel on the travel surface; a load sensor for measuring the load on the motor; further comprising an attitude monitoring unit that monitors the attitude of the autonomous driving device based on the acceleration measured by the acceleration sensor; The autonomous mobile device according to claim 1 , wherein the collision detection unit detects the collision based on measurement results from the acceleration sensor and the load sensor when a change occurs in the attitude of the autonomous mobile device.

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