Autonomous mobile body

Abstract

This autonomous mobile body comprises: a travel unit that has a drive wheel and a chassis and is capable of moving linearly and turning to the left and right; a second unit that is disposed at the upper part of the travel unit and has a top plate and a swinging mechanism for performing a swing motion to move about an axis extending in the vertical direction with respect to the travel unit; a lower object detection sensor that detects an object existing in the travel direction of the travel unit; an upper object detection sensor that detects an object existing in the vicinity of the top plate; and a control unit that controls at least one of the travel unit and the second unit in accordance with the result of detection of an object by the lower object detection sensor and the result of detection of an object by the upper object detection sensor.

Description

Autonomous Mobile Vehicle

[0001] The present invention relates to an autonomous moving body.

[0002] Research and development of autonomous mobile robots capable of transporting objects such as food and beverages and luggage has been ongoing. Generally, autonomous mobile robots are equipped with object detection sensors that detect surrounding objects and determine their behavior based on the object detection results. For example, when an autonomous mobile robot detects a surrounding object, it assumes that the object is a person and performs a recognition behavior such as a head shake to notify the robot that it has recognized the person.

[0003] Japanese Patent Application Laid-Open No. 2022-51979

[0004] However, with the above-mentioned conventional technology, when an autonomous mobile robot detects a person nearby, it is not possible to distinguish whether the person is trying to place an object on the top surface of the autonomous mobile robot or whether the person is simply passing by the autonomous mobile robot.

[0005] Therefore, for example, even if a person approaches an autonomous mobile robot and tries to place an object on the top plate of the autonomous mobile robot, the autonomous mobile robot may swivel, causing the top plate to move and making it difficult for the person to place the object on the top plate.

[0006] Therefore, the present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an autonomous moving body that can perform appropriate operations in accordance with the contents of detection of surrounding objects.

[0007] The autonomous mobile body of the present invention comprises a running unit having drive wheels and a chassis and capable of moving straight ahead and turning left and right, a second unit arranged on top of the running unit and having a swivel mechanism for performing a swivel motion around a vertical axis based on the top plate and the running unit, a lower object detection sensor that detects objects in the direction of travel of the running unit, an upper object detection sensor that detects objects near the top plate, and a control unit that controls at least one of the running unit and the second unit depending on the object detection results by the lower object detection sensor and the object detection results by the upper object detection sensor.

[0008] According to the present invention, it is possible to provide an autonomous moving body that can perform an appropriate operation in accordance with the contents of detection of surrounding objects.

[0009] Fig. 1A is a diagram showing the structure of an autonomous mobile robot according to an embodiment. Fig. 1B is a diagram showing the structure of an autonomous mobile robot according to an embodiment. Fig. 2 is a diagram showing the functional configuration of an autonomous mobile robot according to an embodiment. Fig. 3 is a flowchart showing processing by the autonomous mobile robot according to an embodiment.

[0010] The autonomous mobile robot (autonomous moving body) of this embodiment will be described below with reference to the drawings. In the following description, "front and back (directions)" refer to directions parallel to the direction of travel of the autonomous mobile robot. Furthermore, "left and right (directions)" refer to directions perpendicular to the direction of travel of the autonomous mobile robot and parallel to the ground. Furthermore, objects around the autonomous mobile robot may be referred to as "obstacles."

[0011] First, the structure and functional configuration of the autonomous mobile robot R will be described with reference to Figures 1A, 1B, and 2. Figures 1A and 1B are diagrams showing the structure of the autonomous mobile robot R according to an embodiment. Figure 2 is a diagram showing the functional configuration of the autonomous mobile robot R according to an embodiment.

[0012] 1A is an external view of an autonomous mobile robot R. The autonomous mobile robot R can carry objects such as food and drink and luggage, and moves autonomously within mobile environments such as restaurants, homes, facilities, warehouses, factories, and outdoors.

[0013] The autonomous mobile robot R includes a transport unit 1 (second unit) and a traveling unit 2. The traveling unit 2 is roughly rectangular with rounded corners, has four drive wheels 21, and a chassis, and is capable of moving straight ahead and turning left and right.

[0014] The transport unit 1 is barrel-shaped and disposed above the traveling unit 2, and includes an upper body 11 and a lower body 12. The housing of the upper body 11 is fixed to a pendulum mechanism 14 (FIG. 1B) and moves in accordance with the movement of the pendulum mechanism 14. The housing of the lower body 12 is fixed to a rotation mechanism 13 (FIG. 1B) and rotates in accordance with the rotation movement of the rotation mechanism 13.

[0015] 1B is a diagram showing the internal structure of the carrying unit 1 of the autonomous mobile robot R. In other words, the housing parts of the upper body 11 and the lower body 12 in FIG. 1A are not shown in FIG. 1B. The carrying unit 1 includes a rotation mechanism 13 and a pendulum mechanism 14.

[0016] The rotation mechanism 13 is a swing mechanism for performing a swing operation around a vertical axis with the traveling unit 2 as a reference.

[0017] The pendulum mechanism 14 is a transport mechanism for transporting luggage, and includes a front-to-back pendulum mechanism 141 and a left-to-right pendulum mechanism 142. The front-to-back pendulum mechanism 141 is a pendulum mechanism for tilting the top surface (top plate) of the upper body 11 in the front-to-back direction. The left-to-right pendulum mechanism 142 is a pendulum mechanism for tilting the top surface (top plate) of the upper body 11 in the left-to-right direction. Note that an object to be transported by the autonomous mobile robot R is placed on the top surface (top plate) of the upper body 11.

[0018] An upper object detection sensor 111 is provided on the top surface (top plate) of the upper body 11. The upper object detection sensor 111 detects an object in the vicinity of the top plate (for example, within one meter from the top plate). The upper object detection sensor 111 is configured, for example, by a LiDAR (Light Detection and Ranging) or millimeter wave sensor, and transmits a detection signal to the pendulum ECU 147. The upper object detection sensor 111 may also be configured by a camera, an ultrasonic sensor, an infrared sensor, or the like, or may be a combination of multiple means.

[0019] As shown in FIG. 2 , the traveling unit 2 includes a traveling drive unit 22 , a position sensor 23 , a lower object detection sensor 24 , and a traveling ECU 25 .

[0020] The travel drive unit 22 includes an electric motor that drives the drive wheels 21 to rotate.

[0021] The position sensor 23 is a sensor that acquires data for the travel ECU 25 to estimate the position of the autonomous traveling robot R. The position sensor 23 is composed of, for example, a GPS (Global Positioning System) sensor or a rotational angular velocity sensor of the drive wheels 21, and transmits a detection signal to the travel ECU 25.

[0022] The lower object detection sensor 24 is a sensor that detects objects around the autonomous traveling robot R (at least objects in the traveling direction of the traveling unit 2). The lower object detection sensor 24 is composed of, for example, a LiDAR or a millimeter wave sensor, and transmits a detection signal to the traveling ECU 25. The lower object detection sensor 24 may also be composed of a camera, an ultrasonic sensor, an infrared sensor, or the like, or may be a combination of multiple means.

[0023] The travel ECU 25 is an information processing device configured using predetermined hardware and software, and is configured using, for example, a CPU (Central Processing Unit), memory, FPGA (Field Programmable Gate Array), ASIC (Application Specific Integrated Circuit), etc.

[0024] The travel ECU 25 executes various controls. For example, the travel ECU 25 estimates the current position of the autonomous traveling robot R based on detection signals acquired from the position sensor 223. The travel ECU 25 also recognizes obstacles around the autonomous traveling robot R based on detection signals acquired from the lower object detection sensor 24. The travel ECU 25 also generates a travel route from the current position to the destination based on the current position, the destination, and the positions of the obstacles. The travel ECU 25 also controls the travel drive unit 22 to cause the travel unit 2 (and thus the autonomous traveling robot R) to travel along the travel route.

[0025] The rotation mechanism 13 also includes a swing drive unit 131, a rotation angle sensor 132, and a swing ECU 133 (control unit).

[0026] The swing drive unit 131 includes an actuator that rotates the rotation mechanism 13 .

[0027] The rotation angle sensor 132 is a sensor that detects the rotation angle of the rotation mechanism 13 and transmits a detection signal to the swing ECU 133 .

[0028] The swing ECU 133 executes various controls. When the travel ECU 25 moves the autonomous traveling robot R to a destination, and the autonomous traveling robot R turns to the left or right, the swing ECU 133 swings the transport unit 1 in the same direction (the same direction as the turning direction; the same applies below) to put it in a swing state, and before the turning movement changes to a straight movement, swings the transport unit 1 in the opposite direction to return it from the swing state to a non-swing state.

[0029] Furthermore, when the autonomous traveling robot R turns left or right, the swing ECU 133 swings the transport unit 1 in the same direction to put it in a swinging state, and controls the swing of the transport unit 1 up to a position where the front of the transport unit 1 faces the destination. The travel ECU 25, swing ECU 133, and pendulum ECU 147 can communicate with each other via a CAN (Controller Area Network) or the like, and send and receive necessary information.

[0030] The pendulum mechanism 14 includes a left-right pendulum drive unit 143 , a front-rear pendulum drive unit 144 , a position sensor 145 , an acceleration sensor 146 , and a pendulum ECU 147 .

[0031] When the autonomous mobile robot R moves in a left-right direction, left-right acceleration occurs in the autonomous mobile robot R. The left-right pendulum drive unit 143 is a mechanism that causes the upper body 11 to perform left-right pendulum motion to offset the effect of this acceleration so that objects placed on the top surface (top plate) of the upper body 11 do not fall in the left-right direction due to this effect.

[0032] When the autonomous traveling robot R accelerates or decelerates in the forward or backward direction, forward or backward acceleration occurs in the autonomous traveling robot R. The forward or backward pendulum drive unit 144 is a mechanism that causes the upper body 11 to perform a forward or backward pendulum motion to offset the effect of this acceleration so that objects placed on the top surface (top plate) of the upper body 11 do not fall in the forward or backward direction due to this effect.

[0033] The left-right pendulum drive unit 143 and the front-back pendulum drive unit 144 can be controlled in parallel. Therefore, even if acceleration occurs in any direction around 360 degrees around the autonomous mobile robot R, by controlling the left-right pendulum drive unit 143 and the front-back pendulum drive unit 144 in parallel to cancel out the effect of the acceleration, it is possible to prevent an object placed on the top surface (top plate) of the upper body 11 from falling.

[0034] The position sensor 145 is a sensor that acquires data for estimating the position of the pendulum mechanism 14. The position sensor 23 is configured, for example, with a rotational angular velocity sensor or the like, and transmits a detection signal to the pendulum ECU 147. Note that the position sensor 145 may be provided for each of the front-rear pendulum mechanism 141 and the left-right pendulum mechanism 142.

[0035] The acceleration sensor 146 detects the acceleration occurring in the pendulum mechanism 14 and transmits a detection signal to the pendulum ECU 147 .

[0036] The pendulum ECU 147 executes various controls. Based on detection signals acquired from the position sensor 145 and the acceleration sensor 146, the pendulum ECU 147 controls the left-right pendulum drive unit 143 and the front-rear pendulum drive unit 144 to make the upper body 11 perform pendulum motion so that an object placed on the top surface (top plate) of the upper body 11 does not fall due to acceleration generated in the autonomous traveling robot R.

[0037] For the sake of simplicity, the term "controller" hereinafter refers to at least one of the travel ECU 25, the swing ECU 133, and the pendulum ECU 147. The travel ECU 25, the swing ECU 133, and the pendulum ECU 147 are capable of sharing information and operating in cooperation with each other through communication.

[0038] The control unit controls at least one of the traveling unit 2 and the transport unit 1 according to the object detection results of the lower object detection sensor 24 and the object detection results of the upper object detection sensor 111 .

[0039] For example, if the lower object detection sensor 24 detects an object, the upper object detection sensor 111 detects an object, and the time it takes for the upper object detection sensor 111 to detect the object is less than a predetermined time (for example, if a person near the autonomous mobile robot R makes a predetermined non-contact hand motion near the top plate (upper object detection sensor 111)), the control unit controls at least one of the traveling unit 2 and the transport unit 1 to perform a set action (for example, an action corresponding to the hand motion, such as a head-shaking action to express joy or an action to move to a predetermined destination).

[0040] Furthermore, for example, when the lower object detection sensor 24 detects an object, the upper object detection sensor 111 detects an object, and the time it takes for the upper object detection sensor 111 to detect the object is equal to or longer than a predetermined time (for example, when a person near the autonomous mobile robot R places (or is about to place) an object on the top plate), the control unit controls at least one of the traveling unit 2 and the transport unit 1 to operate in a stable traveling mode that is set assuming that an object will be placed on the top plate. In the stable traveling mode, for example, when the top plate is moved, the movement of the traveling unit 2 and the transport unit 1 is reduced so that the object on the top plate does not move easily, and when the autonomous mobile robot R is traveling, the traveling speed is slowed so that the object on the top plate does not move easily.

[0041] Furthermore, for example, if the lower object detection sensor 24 detects an object and the upper object detection sensor 111 does not detect an object (for example, if a person near the autonomous mobile robot R does not make a hand motion near the top plate or place an object on the top plate), the control unit instructs the traveling unit 2 to stop traveling or to avoid the obstacle (detected object).

[0042] Next, processing by the autonomous traveling robot R will be described with reference to Fig. 3. Fig. 3 is a flowchart showing processing by the autonomous traveling robot R according to the embodiment. It is assumed that before this processing starts, the traveling ECU 25 generates a traveling route from the current position to the destination based on the current position, the destination, and the positions of obstacles.

[0043] First, in step S1, it is assumed that the lower object detection sensor 24 detects an object.

[0044] Next, in step S2, the control unit determines whether the upper object detection sensor 111 has detected an object for less than a predetermined time, and if the answer is Yes (for example, if a person near the autonomous mobile robot R makes a predetermined hand motion near the top plate (upper object detection sensor 111)), the control unit proceeds to step S3, and if the answer is No, the control unit proceeds to step S4.

[0045] In step S3, the control unit executes a set operation (for example, an operation corresponding to a hand motion) for at least one of the traveling unit 2 and the transporting unit 1.

[0046] In step S4, the control unit determines whether the upper object detection sensor 111 has detected an object for a predetermined period of time or longer, and if the answer is Yes (for example, if a person near the autonomous mobile robot R places an object on the top plate), the control unit proceeds to step S5, and if the answer is No (for example, if a person near the autonomous mobile robot R does not make a hand motion near the top plate or place an object on the top plate), the control unit proceeds to step S7.

[0047] In step S5, the control unit determines that a person has placed an object on the top plate. Next, in step S6, the control unit transitions to a stable driving mode that is set assuming that an object will be placed on the top plate, and controls at least one of the driving unit 2 and the transport unit 1 to operate in the stable driving mode.

[0048] In step S7, the control unit determines that there is an obstacle (such as a person) in front of (in the direction of travel of) the autonomous mobile robot R. Next, in step S8, the control unit instructs the traveling unit 2 to stop traveling or to avoid the obstacle (object obstructing traveling).

[0049] In this way, the autonomous mobile robot R of this embodiment controls at least one of the traveling unit 2 and the transport unit 1 in accordance with the object detection results of the lower object detection sensor 24 and the upper object detection sensor 111. This allows the autonomous mobile robot R to perform appropriate operations in accordance with the detection results of surrounding objects. Specifically, this is as follows.

[0050] For example, if the lower object detection sensor 24 detects an object, the upper object detection sensor 111 detects an object, and the time it takes for the upper object detection sensor 111 to detect the object is less than a predetermined time, the control unit 2 controls at least one of the traveling unit 2 and the transport unit 1 to execute a set action. This makes it possible, for example, for a person near the autonomous mobile robot R to make a predetermined hand motion near the top board (upper object detection sensor 111), to cause the autonomous mobile robot R to execute an action corresponding to the hand motion.

[0051] Furthermore, if the lower object detection sensor 24 detects an object, the upper object detection sensor 111 detects an object, and the time it takes for the upper object detection sensor 111 to detect the object is equal to or longer than a predetermined time, the system controls at least one of the traveling unit 2 and the transporting unit 1 to operate in a stable traveling mode that is set assuming that an object will be placed on the top plate. This makes it possible to cause the autonomous traveling robot R to operate in the stable traveling mode, for example, when a person near the autonomous traveling robot R places an object on the top plate. This makes it possible to avoid a situation where the autonomous traveling robot R begins to swing its head when a person approaches the autonomous traveling robot R and attempts to place an object on the top plate of the autonomous traveling robot R.

[0052] Furthermore, if the lower object detection sensor 24 detects an object and the upper object detection sensor 111 does not detect an object, the autonomous mobile robot R is instructed to stop traveling or to avoid the obstacle (object obstructing traveling). As a result, for example, if a person near the autonomous mobile robot R does not make a hand motion near the tabletop or place an object on the tabletop, the autonomous mobile robot R can be caused to stop traveling or to avoid the obstacle (object obstructing traveling).

[0053] The program executed by the autonomous mobile robot R of this embodiment can be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD (Compact Disc)-ROM (Read Only Memory), a flexible disk (FD), a CD-R (Recordable), or a DVD (Digital Versatile Disk).The program may also be provided or distributed via a network such as the Internet.

[0054] Although an embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, and are also included in the invention and its equivalents as defined in the claims.

[0055] For example, the acceleration sensor 146 may be provided in the traveling unit 2 instead of in the pendulum mechanism 14. However, in that case, the acceleration sensor 146 does not detect the acceleration due to the pendulum motion of the pendulum mechanism 14 or the rotational motion of the rotation mechanism 13. However, the pendulum ECU 147 can determine the control content for the left-right pendulum drive unit 143 and the front-rear pendulum drive unit 144 by using not only the detection signal from the acceleration sensor 146, but also previous control signals from the pendulum ECU 147 to the left-right pendulum drive unit 143 and the front-rear pendulum drive unit 144, and previous control signals from the swing ECU 133 to the swing drive unit 131.

[0056] On the other hand, if the acceleration sensor 146 is provided in the pendulum mechanism 14 as in the above-described embodiment, such complicated processing is not necessary because the acceleration sensor 146 detects the acceleration due to the pendulum motion of the pendulum mechanism 14 and the rotational motion of the rotation mechanism 13. In other words, the control contents for the left-right pendulum drive unit 143 and the front-rear pendulum drive unit 144 can be determined by simple processing based only on the detection signal from the acceleration sensor 146.

[0057] Furthermore, the present invention can be widely applied to autonomous mobile bodies in general, in addition to autonomous robots.

[0058] Furthermore, when the lower object detection sensor 24 or the upper object detection sensor 111 detects an object, it may detect the presence of the object, or it may detect a specific movement of the object.

[0059] 3 does not distinguish between cases where the time it takes for the lower object detection sensor 24 to detect an object, but this is not limiting. In other words, when the lower object detection sensor 24 detects an object, the subsequent behavior of the autonomous mobile robot R may be different depending on whether the detection time is long or short.

[0060] 3, steps S2 and S3 are classified based on whether the object detection time by the upper object detection sensor 111 is less than or equal to a predetermined time, but this is not limiting. For example, a first set time and a second set time longer than the first set time may be set in advance, and if the object detection time by the upper object detection sensor 111 is closer to the first set time, step S2 may be answered Yes, and if the object detection time by the upper object detection sensor 111 is closer to the second set time, step S2 may be answered No and step S3 may be answered Yes.

[0061] In addition to the travel ECU 25, swing ECU 133, and pendulum ECU 147 shown in FIG. 2, an integrated ECU that controls them in an integrated manner may be provided separately, and the integrated ECU may execute the processing and control specific to the present invention.

[0062] 1...Transport unit, 2...Travel unit, 11...Upper body (transport mechanism), 12...Lower body (swing mechanism), 13...Rotation mechanism (swing mechanism), 21...Drive wheel, 25...Travel ECU (control unit), 131...Swing drive unit (swing mechanism), 132...Rotation angle sensor (swing mechanism), 133...Swing ECU (control unit), 147...Pendulum ECU, R...Autonomous traveling robot (autonomous mobile body)

Claims

1. An autonomous mobile body comprising: a traveling unit having drive wheels and a chassis and capable of moving straight ahead and turning left and right; a second unit arranged on top of the traveling unit and having a swivel mechanism for swivel movement around a vertical axis based on the top plate and the traveling unit; a lower object detection sensor that detects objects in the direction of travel of the traveling unit; an upper object detection sensor that detects objects in the vicinity of the top plate; and a control unit that controls at least one of the traveling unit and the second unit in accordance with the object detection results by the lower object detection sensor and the object detection results by the upper object detection sensor.

2. The autonomous mobile body described in claim 1, wherein the control unit controls at least one of the traveling unit and the second unit to execute a set action when the lower object detection sensor detects an object, the upper object detection sensor detects an object, and the time it takes for the upper object detection sensor to detect the object is less than a predetermined time.

3. The autonomous mobile body described in claim 1, wherein, when the lower object detection sensor detects an object, the upper object detection sensor detects an object, and the time it takes for the upper object detection sensor to detect the object is longer than a predetermined time, the control unit controls at least one of the traveling unit and the second unit to operate in a stable traveling mode that is set assuming that an object will be placed on the top plate.

4. The autonomous mobile body described in claim 1, wherein, when the lower object detection sensor detects an object and the upper object detection sensor does not detect an object, the control unit instructs the traveling unit to stop traveling or to avoid the detected object.

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