Autonomous mobile device

Abstract

The simple structure ensures reliable detection of steps when moving in all directions. [Solution] An autonomous mobile device 1 having a main direction of movement in one direction, comprising: wheels 32L to 33R that can move in all directions with respect to the main direction of movement without changing their posture; a front step detection sensor 8 that detects steps in the left and right diagonal forward directions with respect to the main direction of movement; and a rear step detection sensor 9 that detects steps in the left and right diagonal rear directions with respect to the main direction of movement.

Description

Technical Field

[0001] The present invention relates to an autonomous mobile device.

Background Art

[0002] Conventionally, autonomous mobile devices such as cleaning robots have been known. In an autonomous mobile device, a method of detecting that there is a step such as a staircase at the travel destination by providing a sensor for measuring the height of the floor surface at the travel destination is known (Patent Documents 1 and 2).

[0003] In addition, there is a mechanism that can move omnidirectionally without depending on the device posture such as an omni-wheel or a mecanum wheel (Patent Document 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the omnidirectionally movable structure described in Patent Document 3, there is a problem that the detection of steps does not work well only with the sensors described in Patent Documents 1 and 2, which assume movement only forward and backward In order to solve this problem, when a sensor capable of detecting omnidirectionally or a sensor capable of changing the detection direction is provided, there is a problem that the structure becomes complicated, the manufacturing cost becomes too high, and the control processing for safe driving becomes too much. In particular, for cleaning robots, lateral movement is not frequent, and the goal is simply to prevent them from falling down steps, so a suitable structure was desired.

[0006] This invention has been made in view of the above circumstances, and aims to provide an autonomous mobile device that can move in all directions, not just the front and back directions, with a simple structure, and that can detect steps while minimizing blind spots that cannot be detected by sensors. [Means for solving the problem]

[0007] (1) An autonomous mobile device according to one aspect of the present invention is A trolley and Wheels attached to the trolley, which move the trolley in all directions on the running surface while maintaining the posture of the trolley, An autonomous mobile device equipped with, If one of the directions of movement of the autonomous mobile device is designated as the primary direction of movement, A forward step detection sensor detects a step in the running surface located diagonally forward to the left and right with respect to the main direction of movement, and which is located outside the trolley when viewed from the main direction of movement. A rear step detection sensor that detects a step in the running surface located diagonally to the left and right rear with respect to the main direction of movement, and located outside the trolley when viewed from the main direction of movement, Equipped with, This resolved the above issues. (2) The autonomous mobile device of the present invention, in the above (1), The aforementioned front step detection sensor and rear step detection sensor are optical sensors (TOF sensors) that measure the distance to the running surface. It is possible. (3) The autonomous mobile device of the present invention, in the case of (1) or (2) above, The autonomous mobile device has a rectangular (square) contour with sides parallel to the main direction of movement when viewed from above, The front step detection sensor and the rear step detection sensor are provided at each corner of the rectangular (square) contour. It is possible. (4) The autonomous mobile device of the present invention, in the above (3), The lower device to which the aforementioned wheels are attached, An upper device having at least the corners spaced apart in the height direction from the lower device, It has, The outer surfaces of the lower device and the upper device have a gap in the height direction at least at the corners. The front step detection sensor and the rear step detection sensor are provided at the lower end of the upper device and emit sensor light from the gap. It is possible. (5) The autonomous mobile device of the present invention, in the above (1) or (2), Of the aforementioned trolley, a suction nozzle is provided at the front lower end position in the main direction of movement, The vacuum cleaner body is detachably mounted on the trolley and connected to the suction nozzle, It is a cleaning robot equipped with It is possible.

[0008] According to the configuration described in (1) above, when the vehicle travels in all directions without changing its posture, not just in the forward and backward directions and the associated diagonal directions, the front step detection sensor and the rear step detection sensor can detect a step in the direction of travel that is lower than the travel surface to the extent that the autonomous mobile device would be unable to travel. This allows the vehicle to stop its travel or change direction before the wheels reach the step. As a result, step detection is possible for all-directional movement with a simple configuration of only four sensors: a mechanism capable of autonomous travel in a linear direction, plus a configuration with a front step detection sensor and a rear step detection sensor. Furthermore, in the primary direction of movement (forward), which has the highest frequency of movement, the front step detection sensors at the left and right positions can detect the step, enabling step detection over a wide range. In addition, in the opposite direction of the primary direction of movement (rearward), which has the next highest frequency of movement, the rear step detection sensors at the left and right positions can detect the step, enabling step detection over a wide range.

[0009] Here, the main direction of movement can be set as the forward direction of the trolley. In this case, for example, the direction perpendicular to the main axle of the wheels may be set as the forward direction. In the autonomous mobile device of the present invention, the trolley can move along the running surface in all directions, including the forward direction. Furthermore, the left and right diagonal forward directions relative to the main direction of movement, and the outside of the trolley as viewed from the main direction of movement, means the range that is outside the outline of the trolley as viewed from above in the lateral direction (left and right direction) perpendicular to the forward direction, and in front of the outline of the trolley as viewed from above in the forward direction. The left and right diagonal forward outward directions relative to the main direction of movement mean the direction that is in front of the outline of the trolley as viewed from above, and the direction that is further outward from the outline of the trolley as viewed from above in the left and right directions. Furthermore, the left and right diagonal rear directions relative to the main direction of movement, and the outside of the vehicle as viewed from the main direction of movement, means the range that is outside the outline of the trolley as viewed from above in the lateral direction (left and right direction) perpendicular to the rear direction, and in the rear of the vehicle as viewed from above. The directions diagonally rearward and outward relative to the main direction of movement are those that are behind the outline of the bogie when viewed from above, and that are also directions that are further outward from the outline of the bogie when viewed from above.

[0010] The wheels only need to be configured to allow the autonomous mobile device's trolley to move in all directions without changing its orientation, and are configured to be appropriately controlled to enable such movement. The autonomous mobile device may have a control unit (control mechanism) that controls the wheels. Furthermore, "moving without changing posture" here means that the autonomous mobile device travels or moves in a predetermined direction without changing the direction in which the main direction of movement of the trolley is facing relative to the travel surface. Furthermore, a step or unevenness in the road surface means that the autonomous mobile device is lower than the driving surface to the extent that it could tip over or become unable to recover.

[0011] According to the configuration described in (2) above, as the front step detection sensor and the rear step detection sensor, an optical sensor, particularly a ToF sensor (Time of Flight sensor) can be adopted. As a result, with an inexpensive optical sensor, accurate measurement can be achieved using sensor light. In addition, since the portion through which the sensor light passes can be small, it becomes easy to enhance the design quality of the autonomous mobile device. Here, the ToF sensor is a sensor that measures the distance to an object (step) by irradiating light such as laser light. The ToF sensor measures the distance to an object by measuring the time it takes for the light irradiated from the light source to be reflected by the object and return to the sensor (photodetector). The ToF sensor focuses on the fact that the speed of light in the air is always constant, and measures the distance based on the round-trip time of light.

[0012] According to the configuration described in (3) above, by simply arranging the front step detection sensor and the rear step detection sensor at the four corners respectively, it becomes possible to install the front step detection sensor and the rear step detection sensor at the position that protrudes most outward from the contour shape when viewed from above, both in the front-rear direction and in the left-right direction. The front step detection sensor and the rear step detection sensor can be positioned outside either of the two sides in the rectangular contour of the autonomous mobile device where their sensing positions intersect at the corners.

[0013] According to the configuration described in (4) above, an optical sensor capable of irradiating measurement light can be arranged at a position that becomes the gap between the lower device and the upper device. As a result, in this gap where the lidar sensor is arranged when performing autonomous movement, it becomes easily possible to provide the front step detection sensor and the rear step detection sensor at a position closer to above than this lidar sensor. Therefore, the sensor light irradiated to detect a step can be irradiated obliquely downward from the gap above the lower device, and detection can be ensured. Here, the lidar sensor detects the surroundings of the autonomous mobile device horizontally from a gap with a certain height, while the front step detection sensor and the rear step detection sensor detect the traveling surface (floor surface) obliquely downward from the gap.

[0014] By irradiating the sensor light obliquely downward from a gap above the lower device, the light transmission part or light transmission hole for irradiating the sensor light is not conspicuous, and the design property can be enhanced. Also, by making the contour of the upper device smaller than the contour of the lower device when viewed from above, it is possible to irradiate the sensor light in an oblique direction from the front step detection sensor and the rear step detection sensor, enabling necessary step detection.

[0015] According to the configuration of (5) above, the autonomous mobile device, which is a cleaning robot, can travel in all directions without changing the posture of the suction nozzle and without being hindered from traveling by steps. As a result, efficient autonomous cleaning can be performed in a short time without leaving unprocessed areas.

Effects of the Invention

[0016] According to the present invention, it is possible to achieve the effect of providing an autonomous mobile device that can detect steps with a simple structure and efficiently perform autonomous travel.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view showing a first embodiment of the autonomous mobile device according to the present invention. [Figure 2] It is a side view showing a first embodiment of the autonomous mobile device according to the present invention. [Figure 3] It is a perspective view showing sensing in a first embodiment of the autonomous mobile device according to the present invention. [Figure 4] It is a side view showing sensing in a first embodiment of the autonomous mobile device according to the present invention. [Figure 5] It is a front view showing sensing in a first embodiment of the autonomous mobile device according to the present invention. [Figure 6] It is a schematic plan view showing sensing in a first embodiment of the autonomous mobile device according to the present invention. [Figure 7]This is a schematic plan view showing the sensing operation in a first embodiment of the autonomous mobile device according to the present invention. [Figure 8] This is a schematic plan view showing the sensing operation in a first embodiment of the autonomous mobile device according to the present invention. [Figure 9] This is a perspective view showing a second embodiment of the autonomous mobile device according to the present invention. [Modes for carrying out the invention]

[0018] A first embodiment of the autonomous mobile device according to the present invention will be described below with reference to the drawings. Figure 1 is a perspective view showing the autonomous mobile device in this embodiment. Figure 2 is a side view showing the autonomous mobile device in this embodiment. In the figures, reference numeral 1 denotes the autonomous mobile device.

[0019] The autonomous mobile device 1 according to this embodiment is various types of robots capable of autonomous movement, such as cleaning robots and security robots. In this embodiment, a cleaning robot will be used as an example. Hereafter, the lower right side of Figure 1 will be considered the front side of the cleaning robot (autonomous mobile device) 1. The cleaning robot 1 cleans offices, commercial facilities, accommodation facilities, etc., by autonomously moving across the floor surface without human intervention and sucking up and collecting dust and dirt that has fallen on the floor. The cleaning robot 1 has a main direction of movement. The main direction of movement is the forward direction for the cleaning robot 1. The forward direction for the cleaning robot 1 is defined by the suction nozzle 71, which will be described later.

[0020] As shown in Figures 1 and 2, the cleaning robot 1 comprises an upper device 2 to which the vacuum cleaner body 70 is fixed, a lower device (cart, mobile cart) 3 with a mobile function, a connecting body 4, lidar sensors (distance sensors) 5 and 6, and step detection sensors 8 and 9. The cleaning robot 1 is configured to be able to move autonomously.

[0021] The upper device 2 is erected on the lower device 3. The connecting body 4 is a connecting part that connects the upper device 2 and the lower device 3. The lidar sensors 5 and 6 are positioned on the front and rear sides of the connecting body 4. The upper device 2 and the lower device 3 are spaced apart from each other in the vertical direction (height direction). A gap G is formed between the upper device 2 and the lower device 3 when viewed from the outer circumference. The lower end of the upper device 2 and the upper end of the lower device 3 are parallel to each other. The lower end of the upper device 2 and the upper end of the lower device 3 are both approximately horizontal. The upper device 2 has a rectangular contour shape when viewed from above. The lower end of the upper device 2 has a rectangular contour shape when viewed from above.

[0022] The upper unit 2 mainly consists of a frame 20, a battery 21, a control unit (control section) 22, a vacuum cleaner body 70, and an outer casing 80. For the sake of explanation, only the outer shapes of the outer casings 80 and 90 are shown with dashed lines in Figure 2.

[0023] The frame 20 is constructed as a rectangular parallelepiped skeleton that is approximately square in shape when viewed from above. The front-to-back dimension of the frame 20 is approximately the same as the left-to-right dimension. In this invention, a frame is considered approximately square if the front-to-back dimension is between 8 / 10 and 12 / 10 of the left-to-right dimension. The frame 20 has a flat mounting surface 20a at its upper end, on which the vacuum cleaner body 70 can be placed. The vacuum cleaner body 70 is surrounded by an outer casing 80 fixed to the frame 20, restricting its movement in the front-to-back and left-to-right directions. The means for fixing the vacuum cleaner body 70 to the frame 20 may be, for example, by using a belt, or by using both the upper outer casing 80 and a belt, and may be changed as appropriate. In addition, a raised piece may be provided on the mounting surface 20a to prevent the vacuum cleaner body 70 from falling.

[0024] The battery 21 is formed in a roughly cubic shape and is positioned and fixed within the frame 20. Furthermore, the battery 21 has a larger storage capacity, is larger and heavier than the battery 31 of the lower device 3 (described later), and is primarily used to power the vacuum cleaner body 70. Note that the battery 21 may also consist of multiple batteries arranged within a battery case.

[0025] The control device 22 is mounted and fixed to the frame 20. The control device 22 controls the power supply to the vacuum cleaner body 70, controls the equipment related to movement (described later), and so on. Alternatively, a separate control device for movement may be provided on the lower device 3, and this control device may be used to control movement.

[0026] The vacuum cleaner body 70 is connected via a pipe 72 to a suction nozzle 71 positioned opposite the floor surface to suck up dust from the floor. The vacuum cleaner body 70 is the main body of a commercial vacuum cleaner that operates on commercial power, and includes a housing for a paper bag, casters, a suction fan (not shown), and a cord with a plug (not shown). The vacuum cleaner body 70 is driven by AC power supplied by an inverter (not shown) via the cord with a plug. The inverter converts the DC current supplied from the battery 21 into AC current. Furthermore, the vacuum cleaner body 70 can also be used for manual operation by electrically connecting the cord with a plug to a commercial power source.

[0027] The lower unit 3 has a rectangular outline when viewed from above. The upper end of the lower unit 3 has a rectangular outline when viewed from above. The lower unit 3 mainly consists of a main body 30, a battery 31, drive wheels 32L, 32R, 33L, 33R, bumpers 34, 35, and an exterior 90 (see Figure 6). The main body 30 is constructed in a box shape that is roughly square when viewed from above.

[0028] The battery 31 is a rectangular parallelepiped that is elongated in the left-right direction and is positioned in the main body 30 between the front drive wheels 32L, 32R and the rear drive wheels 33L, 33R. The battery 31 is smaller than the battery 21 of the upper device 2 and has a shorter height than each of the drive wheels 32L, 32R, 33L, 33R. The main body 30 has a longer height than the battery 31 and a shorter height than each of the drive wheels 32L, 32R, 33L, 33R. The battery 31 supplies power to the equipment related to the movement of the cleaning robot 1. The battery 31 is used to drive, for example, each of the drive wheels 32L, 32R, 33L, 33R, distance sensors 5, 6, etc. Note that power to the distance sensors 5, 6 may be supplied from the battery 21.

[0029] Each drive wheel 32L, 32R, 33L, and 33R is a so-called Mecanum wheel or omniwheel, having multiple rollers. Each drive wheel 32L, 32R, 33L, and 33R is equipped with its own individual drive motor. Each drive motor is connected to the control device 22 of the upper unit 2. The magnitude and input direction of the applied voltage supplied from the battery 31 to each drive motor are individually switched by the control device 22 of the upper unit 2. As a result, the rotation speed and rotation direction of each drive wheel 32L, 32R, 33L, and 33R are individually controlled. The cleaning robot 1 combines the driving of each drive wheel 32L, 32R, 33L, and 33R with the rolling of each roller in contact with the floor surface. This allows the cleaning robot 1 to move smoothly in all directions, including lateral movement.

[0030] The front bumper 34 is formed in a U-shape when viewed from above and is fixed to the main body 30, enclosing the outside of the exterior 90 which is fixed to the front drive wheels 32L, 32R and the main body 30. The bumper 34 is also provided with a switch (not shown) that turns ON when it comes into contact with an obstacle. The rear bumper 35 is formed in a U-shape when viewed from above and is fixed to the main body 30, enclosing the outside of the rear drive wheels 33L, 33R and the exterior 90. It is also provided with a switch (not shown) similar to the front bumper 34.

[0031] When the control device 22 detects that the switch on at least one of the bumpers 34 or 35 is turned ON, it selects an appropriate avoidance action, such as stopping or reversing, and determines the magnitude and direction of the voltage applied to the drive motor. The main body 30 of the lower device 3 is positioned slightly rearward from the center in the front-rear and left-right directions within the rectangular frame formed by the front and rear bumpers 34 and 35. A nozzle 71 is positioned between the main body 30 and the front bumper 34, and on the front right end of the main body 30. The right end of the nozzle 71 is exposed outside the front right corner of the front bumper 34. This makes it possible to clean the area to the right and outside of the bumper 34.

[0032] The connecting body 4 mainly consists of a base material 40, an overhanging member 43 fixed to the front of the left and right wall portions 40a and 40b of the base material 40 with a portion of it extending forward, and an overhanging member 44 fixed to the rear ends of the left and right wall portions 40a and 40b with a portion of it extending rearward. The base material 40 is formed in a U-shape when viewed from above, and has left and right wall portions 40a and 40b, and a flat plate-shaped connecting portion 40c that is continuous with their rear ends at approximately perpendicular angles. The structural strength of the base material 40 is enhanced because it is formed in a U-shape. The right wall portion 40a and the left wall portion 40b are symmetrical. These will be explained using the right wall portion 40a as an example, and the explanation of the left wall portion 40b will be omitted.

[0033] The right-side wall section 40a is formed in a U-shape, having flanges extending vertically to the right when viewed from the front, and vertical sections extending vertically across them. The upper flange is fixed to the frame 20 of the upper device 2, and the lower flange is fixed to the main body 30 of the lower device 3. Furthermore, the structural strength of the wall section 40a is enhanced by its U-shape. The front half and upper half of the wall section 40a is cut out in a roughly rectangular shape, and the height at the rear is greater than the front, so to speak, it is formed in a sideways P-shape.

[0034] The overhanging member 43, positioned on the front side, has a connecting portion 43a fixed to the front of the wall portions 40a and 40b, and an overhanging portion 43b that extends forward, approximately perpendicular to the lower end of the connecting portion 43a. A distance sensor 5 is fixed to the upper surface of the overhanging portion 43b. The connecting body 4 has a roughly square horizontal cross-section, formed by the vertical portions of the wall portions 40a and 40b of the base material 40, the connecting portion 40c of the connecting portion 40c of the overhanging member 43. The overhanging member 44, positioned on the rear side, has fixing portions 44a, 44a fixed below the rear ends of the wall portions 40a and 40b, and a flat plate-shaped overhanging portion 44b that extends further rearward from the fixing portions 44a, 44a. A distance sensor 6 is fixed to the upper surface of the overhanging portion 44b (see Figure 6).

[0035] Distance sensors 5 and 6 are so-called LiDAR sensors that measure distance using light. Distance sensors 5 and 6 are connected to the control device 22. Distance sensors 5 and 6 are positioned inside the contour of the upper device 2 when viewed from above. Distance sensors 5 and 6 are positioned between the upper device 2 and the lower device 3 in the height direction. Distance sensors 5 and 6 are positioned in the gap G when viewed from the side. Distance sensors 5 and 6 are positioned on the lower side of the gap G. Detection units 5a and 6a of distance sensors 5 and 6 are positioned at approximately the same height. The detection units 5a and 6a are capable of sensing over approximately 360 degrees in the horizontal direction and can measure the distance to obstacles within a sensing range of approximately 0.5m to 10m. The distance sensor may also be capable of measuring in three dimensions. Furthermore, the detectable range in terms of angle, short distance, and long distance may be changed as appropriate.

[0036] Figure 3 is a perspective view showing the sensing in the autonomous mobile device of this embodiment. Figure 4 is a side view showing the sensing in the autonomous mobile device of this embodiment. Figure 5 is a front view showing the sensing in the autonomous mobile device of this embodiment. Figure 6 is a plan view showing the sensing operation in the autonomous mobile device of this embodiment. The step detection sensors 8 and 9 are positioned at the four corners of the upper device 2, which has a rectangular outline when viewed from above. The step detection sensors 8 and 9 consist of a front step detection sensor 8 and a rear step detection sensor 9.

[0037] The front step detection sensor 8 includes a right front step detection sensor 8a located at the right corner of the front lower end of the upper device 2, and a left front step detection sensor 8b located at the left corner of the front lower end of the upper device 2. The rear step detection sensor 9 includes a right rear step detection sensor 9a located at the right corner of the rear lower end of the upper device 2, and a left rear step detection sensor 9b located at the left corner of the rear lower end of the upper device 2. The step detection sensors 8 and 9 are both optical sensors, specifically ToF sensors (Time of Flight sensors). The step detection sensors 8 and 9 measure the distance to the running surface by irradiating sensor light, such as laser light, onto the running surface diagonally below the gap G. Unlike the distance sensors 5 and 6, the step detection sensors 8 and 9 measure the distance to a specific point on the irradiation target, which is the sensing position (described later). The step detection sensors 8 and 9 are connected to the control device 22.

[0038] Furthermore, the step detection sensors 8 and 9 are not limited to ToF sensors; laser displacement sensors, ultrasonic sensors, and other sensors can also be used, as long as they can measure the distance to the sensing position. The step detection sensors 8 and 9 are positioned near the lower end of the upper casing 80. The step detection sensors 8 and 9 are positioned inside the upper casing 80. The step detection sensors 8 and 9 are positioned in a location that is not visible from the outside. Near the lower end of the upper outer casing 80, notches 88 and 89 are formed so that step detection sensors 8 and 9 can sense the difference.

[0039] The notches 88 and 89 are arranged in a shape that allows sensor light from the step detection sensors 8 and 9 to pass through to a predetermined sensing position. The notches 88 and 89 are located at the four corners near the lower end of the upper casing 80. The notches 88 and 89 may be formed in a position visible from the outside on the upper casing 80. The notches 88 and 89 may be formed in a position not visible from the outside on the upper casing 80, such as in a portion where the lower end is folded inward.

[0040] Alternatively, near the lower end of the upper outer casing 80, a transparent portion may be formed instead of the notches 88 and 89, allowing sensor light to pass through so that the step detection sensors 8 and 9 can sense the step. In this case as well, it is preferable that the transparent portion be formed in a shape corresponding to the notches 88 and 89.

[0041] As shown in Figures 3 to 6, the right front step detection sensor 8a is positioned inside the notch 88 at the lower right front of the upper outer casing 80. The right front step detection sensor 8a emits sensor light L8a. The target of the light emitted by the right front step detection sensor 8a is the right front sensing position S8a. When the light is emitted onto the running surface, which is a horizontal plane, the right front sensing position S8a is located to the right and in front of the contour of the lower device 3 when viewed from above. In other words, the right front sensing position S8a is located in front of the front end of the contour of the lower device 3. The right front sensing position S8a is located to the right and outside of the right end of the contour of the lower device 3.

[0042] The left front step detection sensor 8b is positioned inside the notch 88 at the lower left front of the upper outer casing 80. The left front step detection sensor 8b emits sensor light L8b. The target of the left front step detection sensor 8b's illumination is the left front sensing position S8b. When the light is shone onto the horizontal driving surface, the left front sensing position S8b is located to the left and in front of the contour of the lower device 3 when viewed from above. In other words, the left front sensing position S8b is located in front of the front end of the contour of the lower device 3. The left front sensing position S8b is located to the left and outside of the left end of the contour of the lower device 3.

[0043] The right rear step detection sensor 9a is positioned inside the notch 89 at the lower right rear end of the upper casing 80. The right rear step detection sensor 9a emits sensor light L9a. The target of the light emitted by the right rear step detection sensor 9a is the right rear sensing position S9a. When the light is emitted onto a horizontal driving surface, the right rear sensing position S9a is located to the right and rear of the contour of the lower device 3 when viewed from above. In other words, the right rear sensing position S9a is located behind the rear end of the contour of the lower device 3. The right rear sensing position S9a is located to the right and outside of the right end of the contour of the lower device 3.

[0044] The left rear step detection sensor 9b is positioned inside the notch 89 at the lower left rear end of the upper casing 80. The left rear step detection sensor 9b emits sensor light L9b. The target of the left rear step detection sensor 9b's illumination is the left b-direction sensing position S9b. When the light is shone onto a horizontal driving surface, the left rear sensing position S9b is located to the left and rear of the contour of the lower device 3 when viewed from above. In other words, the left rear sensing position S9b is located behind the front end of the contour of the lower device 3. The left rear sensing position S9b is located to the left and outside of the left end of the contour of the lower device 3.

[0045] Before cleaning the room, the control device 22 performs mapping based on distance information and relative position information to obstacles such as walls and pillars in the room, measured by distance sensors 5 and 6 and step detection sensors 8 and 9. When cleaning the room, the control device 22 determines its current position based on distance information and position information measured by distance sensors 5 and 6 and step detection sensors 8 and 9, as well as information such as rotational speed from rotary encoders (not shown) connected to the four drive motors. Then, it queries the mapped map with the current position to determine the magnitude and input direction of the applied voltage for each drive motor.

[0046] The sensing ranges S1 and S2 of the distance sensors 5 and 6 will now be explained. The sensing ranges S1 and S2 are the approximately 250-degree range enclosed by the dashed line in Figure 6, and are shown in shaded area. The sensing ranges S1 and S2 are the distances at which the distance sensors 5 and 6 can actually detect obstacles, and are within a radius of 0.5 m or more from the sensors 5 and 6. On the other hand, the remaining 110-degree range and the area less than a radius of 0.5 m from the distance sensors 5 and 6 are outside the sensing range of the distance sensors 5 and 6. The detection parts 5a and 6a of the distance sensors 5 and 6 are located in the gap (opening) G formed by the separation of the upper device 2 and the lower device 3 by the connecting body 4. The opening G is a slit-shaped space between the lower end of the upper device 2 and the upper end of the lower device 3, which are separated vertically by the connecting body 4. The opening G is open in the radial direction over 360 degrees when the connecting body 4 is considered as the central axis.

[0047] The distance sensor 5 is positioned on the front side of the connecting body 4 within the opening G, so that the front and left and right sides are open, and it is positioned further forward and spaced apart from the connecting portion 43a of the overhanging member 43. The sensing range S1 of the distance sensor 5 shown in Figure 6 can include the area behind the distance sensor 5. The upper front ends of the walls 40a and 40b of the connecting body 4 on the left and right sides of the distance sensor 5 are cut out, preventing the walls 40a and 40b from interfering with the sensing of the distance sensor 5. Since the upper device 2 and lower device 3 house batteries 21 and 31, which require volume, the connecting body 4 can be made shorter in the front-rear and left-right directions, i.e., thinner. This narrows the range in which the walls 40a and 40b and the connecting portion 43a of the overhanging member 43 interfere with the sensing of the distance sensor 5. As a result, the cleaning robot 1 has a wide area of ​​approximately 250 degrees as the sensing range S1 of the distance sensor 5.

[0048] The distance sensor 6 is positioned on the rear side of the connecting body 4 within the opening G, leaving the rear and left and right sides open. In addition, it is positioned behind and spaced apart from the connecting portion 40c of the base material 40. This allows the sensing range S2 of the distance sensor 6 shown in Figure 6 to include the area in front of the distance sensor 6. Since each fixing portion 44a of the protruding member 44 is positioned below the sensing range S2 of the distance sensor 6, interference between each fixing portion 44a and the sensing of the distance sensor 6 is prevented. Because the connecting body 4 is formed to be slender, the range in which the connecting portion 40c and wall portions 40a, 40b of the base material 40 interfere with the sensing of the distance sensor 6 is narrowed. As a result, the cleaning robot 1 has a wide area spanning approximately 250 degrees as the sensing range S2 of the distance sensor 6.

[0049] The step detection sensors 8 and 9 are positioned inside the notches 88 and 89 at the lower corners of the upper device 2 within the opening G, so that the sensor light can be irradiated to sensing positions S8 and S9 without interference from the lower device 3 located below. The step detection sensors 8 and 9 may also be positioned on the surface of the outer casing 80. In this case, the step detection sensors 8 and 9 can be exposed from the outer casing 80.

[0050] Sensing positions S8 and S9 are set independently of sensing ranges S1 and S2. In other words, distance sensors 5 and 6 are used to detect obstacles located above the driving surface and to control the vehicle's movement to avoid collisions, while step detection sensors 8 and 9 are used to detect steps, depressions, or slopes on the driving surface that are lower than the driving surface to the extent that the autonomous mobile device becomes unable to move. Therefore, sensing positions S8 and S9 are distributed around the entire circumference of the contour of the lower device 3 when viewed from above, at approximately equal intervals. In addition, the right front sensing position S8a of the right front step detection sensor 8a, the left front sensing position S8b of the left front step detection sensor 8b, the right rear sensing position S9a of the right rear step detection sensor 9a, and the left rear sensing position S9b of the left rear step detection sensor 9b are set to be greater than the distance at which the control device 22 can stop when a step is detected by the step detection sensors 8 and 9.

[0051] Specifically, the right front sensing position S8a and the left front sensing position S8b are set to be 30 cm forward and 10 cm laterally from the contour of the lower device 3 when viewed from above. The right front sensing position S8a and the left front sensing position S8b are set to be 45 cm forward and 10 cm laterally from the drive wheels 32L and 32R, which are the front wheels. The right rear sensing position S9a and the left rear sensing position S9b are set to be 30 cm rear and 10 cm laterally from the contour of the lower device 3. The right rear sensing position S9a and the left rear sensing position S9b are set to be 45 cm rear and 10 cm laterally from the drive wheels 33L and 33R, which are the rear wheels.

[0052] Furthermore, sensing positions S8a to S9b are all set to be located diagonally outward from the corners. Sensing positions S8a to S9b form a rectangle larger than the contour of the lower device 3 when viewed from above, or the rectangular contour formed by the contact points of the four drive wheels 32L to 33R, with these positions as the corner vertices. Here, regardless of the direction of travel of the drive wheels 32L to 33R with respect to the main direction of movement defined by the posture of the lower device 3, the rectangular contour of sensing positions S8a to S9b reaches the contact points of the four drive wheels 32L to 33R before they reach the contact points of the four drive wheels 32L to 33R. In other words, sensing positions S8a to S9b can reach and detect the step first. As a result, when the cleaning robot 1 is moving in the forward / backward direction, left / right direction, or diagonally between these directions, if a step is detected, the control device 22 can stop the movement without the cleaning robot 1 coming off its wheels or tipping over.

[0053] The right front sensing position S8a and the left front sensing position S8b are located inside the sensing ranges S1 and S2. The right front sensing position S8a and the left front sensing position S8b are closer to the lower device 3 than the sensing ranges S1 and S2. The right rear sensing position S9a and the left rear sensing position S9b are located inside the sensing ranges S1 and S2. The right rear sensing position S9a and the left rear sensing position S9b are closer to the lower device 3 than the sensing ranges S1 and S2.

[0054] The sensing positions S8a to S9b should be set according to the distance at which the control device 22 can stop, and should be set according to the structure and control method of the moving mechanism having drive wheels 32L, 32R, 33L, 33R, etc. In this embodiment, sensing positions S8a to S9b are set to be further away from the bogie 3 in the longitudinal direction than in the lateral direction. This is because, as a characteristic of Mecanum wheels, when the rotational speed of the drive wheel axle is the same, the travel speed in the longitudinal direction is faster than the travel speed in other directions. However, even with a bogie 3 equipped with Mecanum wheels, if the control device 22 controls the movement speed to be the same in all directions, the sensing positions can be set to be the same distance from the bogie 3 in both the longitudinal and lateral directions.

[0055] Furthermore, in the present invention, regardless of the movement mechanism and control method, if the braking distance in the longitudinal direction is L1 and the braking distance in the lateral direction is L2, then it is most preferable that the distance from the trolley 3 to the sensing position in the longitudinal direction : the distance from the trolley 3 to the sensing position in the lateral direction = L1:L2. Here, when the brakes are applied at the maximum speed, the braking distance is defined as the distance from the braking position to the stopping position. In other words, it is preferable to set the sensing position according to the ratio of the distance from the trolley in the longitudinal direction and the lateral direction, in accordance with the ratio of the braking distances in the longitudinal direction and the lateral direction.

[0056] In this embodiment, the cleaning robot 1 has a roughly square horizontal contour shape for the upper device 2 and the lower device 3. Since the contour of the upper device 2 is slightly smaller than that of the lower device 3, when the step detection sensors 8 and 9 at the corners perform sensing diagonally downwards, the lower device 3 does not interfere, and the sensing positions S8a to S9b of the step detection sensors 8 and 9 can be placed around the entire circumference near the horizontal contour of the lower device 3. As a result, the four step detection sensors 8 and 9 alone can reliably detect steps and prevent derailment or tipping over, even when traveling in all directions.

[0057] Because the cleaning robot 1 has a roughly square horizontal contour shape for its upper device 2 and lower device 3, it is possible to prevent the configuration of the cleaning robot 1 from interfering with the sensing of the two distance sensors 5 and 6, while keeping the configuration of the cleaning robot 1 outside the sensing areas of the two distance sensors 5 and 6, and overlapping the sensing ranges S1 and S2 in the vicinity of the side of the cleaning robot 1. As a result, all directions can be included in the sensing ranges S1 and S2 using only the two distance sensors 5 and 6.

[0058] In particular, when the cleaning robot 1 moves in its main direction of movement, it can detect steps using the left and right front step detection sensors 8. When the cleaning robot 1 moves in the rear direction, it can detect steps using the left and right rear step detection sensors 9.

[0059] Figure 7 is a plan view showing the sensing operation in the autonomous mobile device of this embodiment. Figure 8 is a plan view showing the sensing operation in the autonomous mobile device of this embodiment. When the cleaning robot 1 moves to the left, as shown in Figure 7, the left front sensing position S8b and the left rear sensing position S9b first reach the step D. At this time, the drive wheels 32L and 33L have not yet reached the step D. Therefore, the left front step detection sensor 8b and the left rear step detection sensor 9b can detect the step D. Similarly, when the cleaning robot 1 moves to the right, the right front step detection sensor 8a and the right rear step detection sensor 9a can detect the step.

[0060] When the cleaning robot 1 moves diagonally, as shown in Figure 8, the step detection sensors 8 and 9 with the shallowest angle relative to the direction of movement can first detect the step. Here, the left-front sensing position S8b first reaches step D. Therefore, the left-front step detection sensor 8b can detect step D. Thus, even when moving diagonally, step detection is possible for movement in all directions using only four sensors. Furthermore, in the primary direction of movement, which is the most frequent, and the backward direction, which is the second most frequent, step detection is possible using the left and right step detection sensors 8.9, enabling step detection over a wide area.

[0061] Furthermore, by positioning the step detection sensors 8.9 slightly above the distance sensors 5 and 6 in the opening G, more reliable step detection can be achieved for the omnidirectional cleaning robot 1 simply by adding four step detection sensors 8.9, without changing any other configurations. At the same time, this configuration prevents the step detection sensors 8.9 and the distance sensors 5 and 6 from interfering with each other. As a result, the cleaning robot 1 can smoothly clean along walls where dust tends to accumulate without losing its wheels or tipping over.

[0062] The cleaning robot 1 has distance sensors 5 and 6 positioned on the front and rear sides of the connecting body 4 that links the upper device 2 and the lower device 3, respectively, which allows for a wider horizontal sensing range S1 and S2. Furthermore, it simplifies the processing of distance detection in the forward and backward directions. For example, if the cleaning robot has distance sensors positioned on the left and right sides, it would be necessary to identify which distance sensor is measuring the front or rear, and to consider angle corrections relative to the installation position, which would make the processing in the main forward and backward directions complicated. In addition, since the battery 31 for driving is provided in the lower device 3 and the battery 21 for the vacuum cleaner body 70 is provided in the upper device 2, the center of gravity can be shifted towards the lower device 3 for stability.

[0063] Since the cleaning robot 1 has batteries 21 and 31, which require volume, located in the upper device 2 and lower device 3, the vertical dimension of the connecting body 4 can be shortened. This reduces the overall height of the cleaning robot 1, allowing the center of gravity to be closer to the lower device 3. The vertical dimension of the connecting body 4 may be changed as appropriate, as long as the sensing ranges S1 and S2 of the distance sensors 5 and 6 and the sensing positions S8a to S9b of the step detection sensors 8 and 9 are secured. On the other hand, a shorter vertical dimension is preferable from the viewpoint of suppressing swaying when the cleaning robot 1 moves and from the viewpoint of aesthetic appearance.

[0064] In the cleaning robot 1, the smaller battery 31 of the individually provided batteries 21 and 31 is located in the lower unit 3, thus shortening the vertical dimension of the lower unit 3. This makes it easier to position the distance sensors 5 and 6 near the floor surface, allowing for more reliable detection of obstacles in the path of each drive wheel 32L to 33R. By positioning the battery 21 of the upper unit 2 below the vacuum cleaner body 70, the center of gravity of the cleaning robot 1 can be lowered. Therefore, the swaying that may occur when the cleaning robot 1 moves is reduced.

[0065] Since the vacuum cleaner body 70 is powered by a separate battery 21 and the cleaning robot 1 is powered by a separate battery 31, even if the suction motor experiences an excessive load, instantaneous load fluctuations, or inrush current due to something like plastic being sucked into the pipe 72, the effects on the cleaning robot 1 are prevented. The power consumption of the vacuum cleaner body 70 per unit time is greater than the power consumption of the cleaning robot 1, and the storage capacities of each battery are set so that the remaining charge of battery 21 reaches zero faster than the remaining charge of battery 31, thus ensuring that the cleaning robot 1 can be reliably returned to its designated position.

[0066] Because the cleaning robot 1 is equipped with step detection sensors 8.9 and bumpers 34 and 35 at the front and rear of the robot, it is capable of taking evasive action when it comes into contact with an obstacle not only in front but also behind. The step detection sensor 8.9 has sensing positions S8a to S9b diagonally outward in the left and right directions, and the switches for the bumpers 34 and 35 are turned ON when an obstacle comes into contact with the left or right side of the bumpers 34 and 35. As a result, the cleaning robot 1 is capable of stopping when it detects a step in the left or right direction, or taking evasive action when it comes into contact with an obstacle. With these features, the cleaning robot 1 can reliably take evasive action when it comes into contact with steps, obstacles, etc., even outside the sensing range of the distance sensors 5 and 6.

[0067] A second embodiment of the autonomous mobile device according to the present invention will be described below with reference to the drawings. Figure 9 is a perspective view showing the autonomous mobile device in this embodiment. The difference between this embodiment and the first embodiment described above lies in the external shape of the device. In this embodiment, other corresponding components may be denoted by the same reference numerals and their descriptions may be omitted.

[0068] As shown in Figure 9, the cleaning robot (autonomous mobile device) 1 of this embodiment mainly consists of a mobile carriage (carriage, lower device) 3 with a suction nozzle 71 attached to its front lower part, and a vacuum cleaner body 70 mounted on the rear upper part of the mobile carriage 3. In this embodiment, the vacuum cleaner body 70 is a commercial vacuum cleaner that operates on commercial power and has a swivel caster (not shown) on its lower part, and is connected to the suction nozzle 71 by a nozzle hose (pipe) 72 arranged inside the cleaning robot 1. In this embodiment, the suction nozzle 71 is narrower in the left-right direction than the mobile carriage 3 and is positioned off-center to the right, but the width and left-right position of the suction nozzle 71 can be freely configured.

[0069] The trolley 3 mainly consists of a pair of left and right wheels 30R, 30L located on the front side of the main body 30 and a pair of left and right wheels 40R, 40L located on the rear side of the main body 30, four traction motors individually connected to these wheels 30R, 30L, 40R, 40L, three traction batteries capable of supplying power to the traction motors, etc., and a control device 22. In addition, the trolley 3 is equipped with four suction batteries that can supply power to the vacuum cleaner body 70 via an inverter, independently of the traction batteries. The three traction batteries and the four suction batteries are all of the same standard and can therefore be interchangeable and shared amongst themselves.

[0070] The trolley 3 comprises an upper casing 80 that covers the vacuum cleaner body 70 and suction battery, etc., mounted on the trolley 3, and a lower casing 90 that covers the main body 30 and the trolley battery, etc. Distance sensors 5, 6 provided at the front and rear of the main body 30 and step detection sensors 8, 9 provided at the inner lower end of the corners of the casing 80 can sense through the gap G formed between the upper casing 80 and the lower casing 90. In this embodiment, sensors 5, 6, 8, and 9 can be composed of non-contact sensors such as laser sensors and ultrasonic sensors.

[0071] The upper casing 80 is mainly assembled in four parts: the front casing 80F, the rear casing 80B, and the left and right side casings 80R and 80L. The upper casing 80 has an opening 81 that follows the outer edge of the vacuum cleaner body 70, and a hose opening 82 through which the nozzle hose 72 can be inserted. Step detection sensors 8 and 9 are positioned on the inside of the four corners at the lower end of the upper casing 80. The lower exterior 90 is more weakened than the upper exterior 80 when viewed from above. Furthermore, both the upper exterior 80 and the lower exterior 90 have a rectangular contour shape when viewed from above.

[0072] The control device can control the movement of the trolley 3 based on distance and position information from sensors 5, 6, 8, and 9, as well as information such as rotational speed from rotary encoders connected to the four traction motors. The control device can individually control the rotational speed and direction of the wheels 30R, 30L, 40R, and 40L by individually switching the magnitude and input direction of the applied voltage to the four traction motors.

[0073] Wheels 30L and 40L are so-called Mecanum wheels equipped with multiple rollers that are inclined at 45 degrees in different directions on the outer circumference of the wheel, and can rotate, turn, move straight forward and backward, and move straight left and right. Wheel 30R is a Mecanum wheel equipped with multiple rollers that are inclined at 45 degrees in the same direction as wheel 40L, and wheel 40R is a Mecanum wheel equipped with multiple rollers that are inclined at 45 degrees in the same direction as wheel 30L. When viewed from the front of the trolley 3, the rollers of wheels 30L and 30R are arranged so that they form a V shape, and when viewed from the rear of the trolley 3, the rollers of wheels 40L and 40R are arranged so that they form a V shape. With this configuration, the cleaning robot 1 can move smoothly in all directions, including forward, backward, left and right, by combining the driving of wheels 30R, 30L, 40R, and 40L by individually controlled motors and the rolling of the rollers in contact with the floor surface.

[0074] The suction nozzle 71 comprises a suction port and a pair of wheels on the left and right sides. These wheels are so-called omni-wheels with multiple rollers along their outer circumference, and are driveable in the forward and backward directions by a drive motor built into the suction nozzle 71. The suction nozzle 71 may also be equipped with a rotating brush at the suction port that can be driven by a drive motor or the like. With this configuration, the suction nozzle 71 can reduce the resistance between the suction nozzle 71 and the floor surface during the movement of the cleaning robot 1 in all directions, particularly during the left-right movement and turning / rotational movement of the cleaning robot 1 described later, by combining the driving of the wheels by the drive motor with the rolling of the rollers in contact with the floor surface. In the forward and reverse movement of the cleaning robot 1, it is preferable that the speed of the trolley 3 driven by the wheels 30R, 30L, 40R, and 40L, and the speed of the suction nozzle 71 driven by the wheels of the suction nozzle 71 are controlled to be approximately the same speed so as not to interfere with the movement of the trolley 3. Alternatively, the control device may coordinate the driving of the wheels of the suction nozzle 71 with the driving of the wheels 30R, 30L, 40R, and 40L.

[0075] The step detection sensors 8 and 9 are positioned at the lower corners of the upper outer casing 80 within the opening G, allowing them to illuminate sensing positions S8 and S9 without interference from the lower trolley 3 or lower outer casing 90 located below. When viewed from above, sensing positions S8a to S9b form a rectangular shape with these positions as corner vertices. The rectangular shape formed by sensing positions S8a to S9b is larger than the rectangular contour of the lower outer casing 90 when viewed from above, or the rectangular shape formed by the contact points of the four drive wheels 30L to 40R.

[0076] In this embodiment, the same effects as those of the above-described embodiment can be achieved.

[0077] Furthermore, in the present invention, it is also possible to individually select and combine each of the configurations in the above-described embodiments.

[0078] For example, in the above embodiment, the vacuum cleaner body was described as being the vacuum cleaner body of a commercial vacuum cleaner, but it is not limited to this, and the upper device may be configured to have components such as a housing and a suction fan that are not detachable, and to have the function of a vacuum cleaner body.

[0079] In the above embodiment, the distance sensors were described as being provided one at the front and one at the rear, but the configuration is not limited to this. They may be provided one on each side, or arranged in a triangular shape when viewed from above, with the connecting part in between. Their positions and number may be changed as appropriate. In the above embodiment, the distance sensor was described as being provided in the connecting portion, but it is not limited to this configuration. As long as multiple sensors are arranged on either side of the connecting portion, they may be fixed to the lower device or to the upper device.

[0080] In the above embodiment, the distance sensor was described as a LiDAR, but it is not limited to this as long as it can sense within the area, and may also be an infrared sensor, ultrasonic sensor, image sensor, etc., and may be changed as appropriate. In the above embodiment, the connecting portion was described as being separate from the upper and lower devices, but it is not limited to this configuration and may be part of at least one of the upper and lower devices. In other words, the configuration may be modified as appropriate as long as an opening can be formed between the upper and lower devices.

[0081] When using an image sensor, it is preferable to use an image sensor capable of detecting the distance from the image to the object, such as a stereo camera or depth camera. In particular, using sensors that utilize laser light, such as LiDAR sensors, makes it less susceptible to the influence of differences in floor surface materials, enabling highly accurate distance measurement. Furthermore, using ultrasonic sensors makes it possible to measure the distance to the floor surface even with transparent flooring materials such as glass or acrylic.

[0082] The angle between the trajectory of the step detection sensors 8 and 9 and the floor surface, that is, the angle of illumination of the sensor light by the step detection sensors, is preferably positioned at an angle of 45 degrees or more upward from the running surface (floor surface). This ensures the detection accuracy of the sensors. Here, the illumination angle of the sensor light can be set as an angle with respect to the horizontal plane on which the running surface is in contact with the four drive wheels.

[0083] In the above embodiment, each drive wheel was described as a Mecanum wheel, but the configuration is not limited to this, and may be changed as appropriate as long as the direction of travel can be changed. In the above embodiment, each drive wheel was described as having a main shaft aligned in the left-right direction. However, the configuration is not limited to this, and drive wheels may have main shafts that are inclined from the left-right direction toward the front-rear direction. In the above embodiment, the cleaning robot was described as having a configuration in which the horizontal cross-section is substantially square, but it is not limited to this. In particular, as long as the shape allows the step sensors to be positioned in four directions relative to the main direction of movement so that their sensing positions can be set, the horizontal cross-section may be rectangular, a polygon other than a square, a circle, or an ellipse, and the shape may be changed as appropriate.

[0084] Furthermore, whether or not the top-view outline of the cleaning robot is roughly square, the step detection sensors may be located in places other than the four corners. In this case, if the top-view outline of the cleaning robot is roughly square, the four corners are the optimal locations for placing the step detection sensors, but the same effect can be obtained even if they are placed in locations other than the four corners. For example, if the top-view outline of the cleaning robot is roughly square, step detection sensors can be placed at two locations slightly towards the center of the front and two locations slightly towards the center of the rear. In this case, the sensing positions can be set to the same positions as when step detection sensors are placed at the four corners. [Explanation of symbols]

[0085] 1… Cleaning robot (autonomous mobile device) 2… Upper device 3…Lower equipment (bogie, running bogie) 4…Connection body 5, 6… LiDAR sensor (distance sensor, sensor) 8,9...Step detection sensor (sensor) 8…Front step detection sensor 8a...Right front step detection sensor 8b... Left front step detection sensor 9…Rear step detection sensor 9a...Right rear step detection sensor 9b... Left rear step detection sensor 20...frames 22…Control device (control unit) 30...Main unit 30R, 30L, 40R, 40L, 32L, 32R, 33L, 33R… Drive wheels (wheels) 70…Vacuum cleaner body 71... Suction nozzle 71…Nozzle 72... Pipe 80... Upper exterior (exterior) 90... Lower exterior (exterior) G... Gap (opening) L8a, L8b, L9a, L9b... Sensor light S1, S2... Sensing range S8a, S8b, S9a, S9b... Sensing position

Claims

1. A trolley and Wheels attached to the trolley, which move the trolley in all directions on the running surface while maintaining the posture of the trolley, An autonomous mobile device equipped with, If one of the directions of movement of the autonomous mobile device is designated as the primary direction of movement, A forward step detection sensor detects a step on the running surface located diagonally forward to the left and right with respect to the main direction of movement, and located outside the trolley when viewed from the front main direction of movement. A rear step detection sensor that detects a step on the running surface located diagonally to the left and right rear with respect to the main direction of movement, and located outside the trolley when viewed from the main direction of movement, Equipped with, Autonomous mobile device.

2. The aforementioned front step detection sensor and rear step detection sensor are optical sensors that measure the distance to the travel surface. The autonomous mobile device according to claim 1.

3. The autonomous mobile device has a rectangular contour with sides parallel to the main direction of movement when viewed from above, The front step detection sensor and the rear step detection sensor are provided at each corner of the rectangular contour. The autonomous mobile device according to claim 1 or 2.

4. The lower device to which the aforementioned wheels are attached, An upper device having at least the corners spaced apart in the height direction from the lower device, It has, The outer surfaces of the lower device and the upper device have a gap in the height direction at least at the corners. The front step detection sensor and the rear step detection sensor are provided at the lower end of the upper device and emit sensor light from the gap. The autonomous mobile device according to claim 3.

5. Of the aforementioned trolley, a suction nozzle is provided at the front lower end position in the main direction of movement, The system comprises a vacuum cleaner body that is detachably mounted on the trolley and connected to the suction nozzle, The autonomous mobile device according to claim 1 or 2.

Images