Cleaning robot

Abstract

This autonomously travelable cleaning robot is configured so as to facilitate transition to an inclined orientation for maintenance. The cleaning robot comprises a handle, and a main body having a step. The main body has a bottom surface facing a surface to be cleaned, a top surface separated from the bottom surface in the vertical direction, and a rear surface positioned behind the cleaning robot in the driving direction and interposed between the bottom surface and the top surface. The handle is arranged on the top surface. The step projects rearward in the driving direction from the rear surface.

Description

Cleaning robot 【0001】 This disclosure relates to a cleaning robot. 【0002】 In recent years, cleaning robots have been used to improve the efficiency of cleaning work in facilities such as offices, commercial facilities, and factories. As such cleaning robots, there is an increasing demand for autonomous cleaning robots that can autonomously travel on the floor while sucking dust. 【0003】 For example, Patent Document 1 discloses a conventional cleaning machine for cleaning the floor. The cleaning machine of Patent Document 1 is configured to be stationary in an inclined manner for detaching the cleaning pad. However, no consideration has been given to a structure or the like for facilitating the operation of shifting to an inclined posture. In particular, cleaning robots used in vast indoor spaces such as factories tend to be enlarged for improving the efficiency of cleaning work, and it is difficult to shift to an inclined posture. 【0004】 Japanese Patent Application Laid-Open No. 01-094818 【0005】 One object of this disclosure is to provide a cleaning robot that has been improved from the conventional one. In particular, in view of the above circumstances, one object of this disclosure is to provide a cleaning robot that can more easily shift to an inclined posture. 【0006】 The cleaning robot provided by an exemplary embodiment of this disclosure includes a main body having steps and a handle. The main body has a bottom surface facing the surface to be cleaned, a top surface spaced apart from the bottom surface in the vertical direction, and a rear surface located behind the driving direction of the cleaning robot and intervening between the bottom surface and the top surface. The handle is provided on the top surface. The steps project rearward in the driving direction from the rear surface. 【0007】 In a preferred embodiment of this disclosure, the cleaning robot rotates around an axis extending in the vertical direction. The steps are provided within a circumference described by the outermost part other than the steps during the rotation operation. 【0008】In a preferred embodiment of the present disclosure, the step has a step side located rearward in the driving direction. The step side is linear when viewed from above. 【0009】 In a preferred embodiment of the present disclosure, the step has a notch at the end of the side surface of the step in a direction perpendicular to the vertical direction. 【0010】 A cleaning robot provided by a preferred embodiment of the present disclosure further comprises wheels, wherein the step includes a step underside facing the surface, and any tangent of the wheel coincides with the step underside. 【0011】 In a preferred embodiment of the present disclosure, the lower surface of the step is provided with an elastic member. 【0012】 In a preferred embodiment of the present disclosure, the handle is annular when viewed from above. 【0013】 The above configuration makes it possible to provide a cleaning robot that can more easily transition to an inclined posture. 【0014】 This is a perspective view showing a cleaning robot according to an exemplary embodiment. This is a perspective view showing a cleaning robot according to an exemplary embodiment. This is a front view showing a cleaning robot according to an exemplary embodiment. This is a rear view showing a cleaning robot according to an exemplary embodiment. This is a top view showing a cleaning robot according to an exemplary embodiment. This is a bottom view showing a cleaning robot according to an exemplary embodiment. This is a left side view showing a cleaning robot according to an exemplary embodiment. This is a cross-sectional view along line VIII-VIII in Figure 3. This is a block diagram showing an overview of a cleaning robot according to an exemplary embodiment. This is a left side view showing a cleaning robot according to an exemplary embodiment in an inclined state. This is a left side view showing a cleaning robot according to an exemplary embodiment in a horizontal state. 【0015】Preferred embodiments of the cleaning robot of this disclosure will be described below with reference to the drawings. Referring to Figures 1 to 9, a cleaning robot A1 according to an exemplary embodiment is shown. The cleaning robot A1 cleans autonomously. More specifically, the cleaning robot A1 is configured to clean target dirt while autonomously moving. Targets for cleaning include floors of buildings such as offices, factories, hospitals, and stores. Types of dirt that can be cleaned include dust, dirt, food scraps, screws, footprints, etc. The cleaning robot A1 comprises a main body 1, an operating unit 200, a detection system 30, a charging terminal 32, and a drive system 70. 【0016】 The wording in this disclosure corresponds as follows: Unless otherwise specified, “A is positioned on B” and “A is positioned on B” include “A is directly positioned on B” and “A is positioned on B with other objects interposed between A and B.” Unless otherwise specified, “A overlaps B when viewed in a certain direction” includes “A overlaps all of B” and “A overlaps a part of B.” Furthermore, “A (the material of) includes material C” includes “A (the material of) consists of material C” and “the main component of A (the material of) is material C.” “Equivalent to A” should not be limited to a configuration consisting only of element A, but may include forms that include elements other than element A. 【0017】In this disclosure, the vertical direction z, the drive direction x, the left-right direction y, and the rotation direction r are described with reference. The vertical direction z corresponds to the height direction of the cleaning robot. The drive direction x corresponds to the drive direction when the cleaning robot is moving in a straight line. The left-right direction y corresponds to one direction perpendicular to the drive direction when the cleaning robot is moving in a straight line. The rotation direction r corresponds to the rotation direction when the cleaning robot is moving in a rotational direction. One or the other of the vertical direction z may be expressed as "up," "down," "upward," and "downward," etc. These terms do not need to coincide with the direction of gravity, but only need to correspond to a direction perpendicular to the surface of the object being cleaned. One or the other of the drive direction x may be expressed as "forward," "backward," "forward," and "backward," etc. These terms only need to correspond to a direction parallel to the surface of the object being cleaned. The terms "top surface" and "bottom surface" used in this disclosure do not necessarily have to refer to the outermost surface. 【0018】 The main body 1 forms the skeleton of the cleaning robot A1. The main body 1 is made of, for example, metal and / or resin, and protects other components of the cleaning robot A1 from external impacts such as collisions with obstacles. The main body 1 has a generally rectangular parallelepiped shape. The shape of the main body 1 is not limited and may be triangular prism or cylindrical. In an exemplary embodiment, the dimensions of the main body 1 are as follows: The size of the main body 1 in the vertical direction z (height) is, for example, 70 cm. The size of the main body 1 in the driving direction x (depth) is, for example, 50 cm. The size of the main body 1 in the left-right direction y (width) is, for example, 50 cm. 【0019】 The main body 1 includes a top surface 2, a bottom surface 3, a rear surface 4, a front surface 5, two sides 6, a body recess 7, a front bumper 8, and two side bumpers 9. The top surface 2, bottom surface 3, rear surface 4, front surface 5, two sides 6, body recess 7, front bumper 8, and two side bumpers 9 are each formed from metal, carbon fiber, and resin, or a combination thereof. The top surface 2 and bottom surface 3 connect to the rear surface 4, the front surface 5, and the two sides 6, respectively. The rear surface 4 and front surface 5 connect to the two sides 6, respectively. Alternatively, the main body 1 may not include the front surface 5, and the two sides 6 may be connected. In this case, the main body 1 is triangular in plan view. 【0020】 The back surface 4 is provided with two protrusions 4a. Each protrusion 4a is a component that contacts the floor surface when the cleaning robot A1 is tilted until it is horizontal. Each protrusion 4a projects backward from the back surface 4. In the illustrated example, the protrusions 4a are rectangular parallelepipeds. Each protrusion 4a is made of, for example, rubber. Each protrusion 4a may have a desired shape, be provided in a desired number, and be made of a desired material, as long as it does not deviate from its function. 【0021】 The top surface 2 and bottom surface 3 are separated from each other in the vertical direction z. The back surface 4 and front surface 5 are separated from each other in the driving direction x. The two side surfaces 6 are separated from each other in the left-right direction y. The two side surfaces 6 are interposed between the top surface 2 and bottom surface 3 in the vertical direction z. The two side surfaces 6 are interposed between the back surface 4 and front surface 5 in the driving direction x. Each side surface 6 is provided with a gripping hole 6A for the user to insert their hand. Cliff sensors that emit infrared rays or ultrasonic waves onto the ground are provided at the bottom of the front bumper 8 and the two side bumpers 9, respectively. More specifically, four cliff sensors 35A are arranged at equal intervals at the bottom of the front bumper 8. One cliff sensor 35A is arranged at the bottom of each of the two side bumpers 9. According to the cliff sensors, the cleaning robot A1 can determine the presence or absence of steps and stop its movement or change its direction of travel. 【0022】 The main body recess 7 is a portion of the main body 1 that is recessed from the front surface 5 towards the rear. The main body recess 7 is located between the front surface 5 and the front bumper 8 in the vertical direction z. The main body recess 7 includes two surfaces facing each other in the vertical direction z and a curved surface facing forward. The front bumper 8 is located below the front surface 5 in the vertical direction z and protrudes forward in the driving direction x. Each side bumper 9 is located below the corresponding side surface 6 in the vertical direction z and protrudes outward in the left-right direction y. 【0023】Additionally, the main body 1 may be equipped with a mechanism for detecting external shocks. Furthermore, the main body 1 may include a shelf 14. The shelf 14 supports the circuit board box 15. The circuit board box 15 includes a circuit unit 16 that performs the electrical functions of the cleaning robot A1. The circuit unit 16 includes, for example, a control device and an inverter, which include a processor and memory. The control device controls, for example, the operation unit 200 and the detection system 30. The inverter converts the DC voltage from the circuit unit 16 so that the multiple motors 7A perform the desired movements. 【0024】 The main body 1 includes a battery housing 41 and a battery cover 43. The battery housing 41 is recessed inward from the back surface 4 into the main body 1. The battery housing 41 is rectangular in shape. The lower surface of the battery housing 41 is located above the bottom surface 3. Alternatively, the lower surface of the battery housing 41 may be integrated with the bottom surface 3. 【0025】 The battery 21 is located in the battery housing 41. The battery 21 is charged either wirelessly or via a wired connection. In an exemplary embodiment, the battery 21 is charged via a wired connection through a charging terminal 32. Power from the battery 21 is supplied to the circuit unit 16, the dust collection assembly 100, the operation unit 200, the detection system 30, and the drive system 70 by a mechanism (not shown). The battery housing 41 is located inside the main body 1 and is closed by a battery cover 43. 【0026】 The main body 1 includes a dust collection assembly 100. The dust collection assembly 100 performs the function of collecting dirt in the cleaning robot A1. The dust collection assembly 100 includes a brush 101, a dust box 102, a duct 103, a chamber 104, a vacuum unit 105, and an exhaust port 106. 【0027】 The brush 101 is connected to the motor 7B and rotates to collect dirt from the target surface. The dust box 102 is detachably mounted below the bottom surface 3. The brush 101 and the dust box 102 are located below the bottom surface 3 in the vertical direction z and are connected to each other. The dust box 102 is connected to the chamber 104 via the duct 103. 【0028】 Chamber 104 houses a dust collection pack (for example, a paper pack) of a size appropriate to its own size. Chamber 104 is connected to a vacuum unit 105. The vacuum unit 105 is connected to an exhaust port 106 located on the rear 4. 【0029】 The vacuum unit 105 includes, for example, a motor and a fan rotated by the motor. The operation of the vacuum unit 105 generates airflow over the dust collection assembly 100. The airflow passes through the dust box 102, duct 103, and chamber 104, and is finally exhausted from the exhaust port 106. Dirt that enters through the brush 101 is collected by this airflow into a dust collection pack attached to the chamber 104. 【0030】 The brush 101 can collect fibrous dirt (e.g., hair). The dust box 102 can collect larger dirt (e.g., food scraps, paper clips, etc.) that cannot be carried to the dust collection pack attached to the chamber 104 by the airflow or suction force generated by the vacuum unit 105. Other dirt can be collected in the chamber 104 via the duct 103. As can be seen from this, the brush 101, dust box 102, and chamber 104 may require maintenance. For example, the brush 101 needs to be replaced with a new one when tangled fibrous dirt is removed or when the brush is worn out. The dust box 102 needs to be removed from the main unit and the accumulated dirt removed. The chamber 104 needs to be replaced with a new dust collection pack. In the cleaning robot A1, the dust box 102 and brush 101 can be maintained by tilting the cleaning robot A1. 【0031】The operating unit 200 is attached to the main body 1 and is a component operated by the user. The operating unit 200 includes a handle 2A, an arm 2B, and an input / output interface 2C. The handle 2A is configured for use by the user to tilt or raise the cleaning robot A1. The arm 2B is configured to allow the user to push the cleaning robot A1 when teaching the cleaning robot A1. The input / output interface 2C is configured to allow the user to input instructions to the cleaning robot A1. The input / output interface 2C may be a terminal electrically connected to the main body 1, or it may be an independent terminal including a computing device. As an example, the input / output interface 2C is a touch-operable panel terminal. The input / output interface 2C may be detachable from the arm 2B. 【0032】 In the illustrated example, the handle 2A is annular when viewed from above (in a plan view). That is, as shown in Figure 5, the handle 2A includes two horizontal bars 2Aa extending in the left-right direction y and two vertical bars 2Ab extending in the drive direction x. The user can tilt the cleaning robot A1 by holding either the horizontal bars 2Aa or the vertical bars 2Ab. Therefore, when tilting the cleaning robot A1 to a horizontal position for maintenance, or when raising it from a horizontally tilted position, the user can select a position on the handle 2A that is easy to hold. Furthermore, when the user wants to switch between the two horizontal bars 2Aa during the tilting process, they can slide their hand along the vertical bar 2Ab, allowing them to always work while holding the handle 2A. As can be understood from the operation of such a handle 2A, the handle 2A only needs to include at least one horizontal bar 2Aa extending in the left-right direction y and at least one vertical bar 2Ab extending in the drive direction x, and may be separate rather than an integrated annular shape. Alternatively, the two horizontal bars 2Aa may extend diagonally in the left-right direction y and be connected to each other without a vertical bar 2Ab. 【0033】Arm 2B is attached to the top surface 2 of the main body 1. In plan view, arm 2B surrounds the portion of the handle 2A other than the rear horizontal bar 2Aa. Arm 2B is configured to rotate between an integrated state and a detached state, with the attachment point to the main body 1 as a pivot point. In the illustrated example, arm 2B is in the integrated state. In Figure 7, the integrated state of arm 2B is shown by a solid line, and the detached state of arm 2B is shown by a dashed line (two-dotted line). 【0034】 In the integrated state, arm 2B is in contact with the main body 1, and the input / output interface 2C is located in front of the main body 1. In the integrated state, the input / output interface 2C can be used by the user to input instructions to the cleaning robot A1 or to check the robot's status. In addition, it can also be used to display information to a person in front of the cleaning robot A1 or to display the rotation direction of the cleaning robot A1 while it is cleaning. In the uncoupled state, arm 2B is separated from the main body 1, and the input / output interface 2C is located behind the main body 1. In the uncoupled state, the user can grasp arm 2B and push the cleaning robot A1 to move it. The input / output interface 2C is connected to arm 2B. 【0035】 The detection system 30 performs the function of enabling the cleaning robot A1 to detect objects. More specifically, the cleaning robot A1 uses the detection system 30 to detect surrounding objects while preparing for and during autonomous travel. The detection system 30 includes an imaging device 31, a sensor system 33, and a plurality of ultrasonic sensors 34. The imaging device 31 is, for example, a 3D camera that detects non-transparent objects. The sensor system 33 is, for example, a LiDAR (Light Detection and Ranging) that measures the distance to an object and the shape of an object. Each ultrasonic sensor 34 detects, for example, transparent objects (e.g., glass) that are difficult to detect with the imaging device 31. 【0036】The imaging device 31 is located on the front surface 5 in the driving direction x. The imaging device 31 is located near the center of the front surface 5 in the left-right direction y. The imaging device 31 is located above the center of the main body 1 in the vertical direction z. As an example, the imaging device 31 is a three-dimensional imaging sensor whose imaging center is oriented downward from the horizontal. That is, the imaging device 31 captures images from a position higher than the center of the main body 1 toward the floor. 【0037】 The sensor system 33 is located in the recess 7 of the main body. The sensor system 33 is positioned near the center of the main body 1 in the left-right direction y. If the sensor system 33 is a LiDAR, it emits laser light forward in the driving direction x and in a part of the left-right direction y, and can measure the distance to an object and the shape of the object by reflecting the laser light. 【0038】 Multiple ultrasonic sensors 34 are provided on the front surface 5 and two side surfaces 6, respectively. In the illustrated example, four ultrasonic sensors 34A are arranged on each of the left and right sides of the imaging device 31. Additionally, four ultrasonic sensors 34B are arranged on each of the front and rear sides of each gripping hole 6A. Each ultrasonic sensor 34 is arranged such that the detection direction of each ultrasonic sensor 34 tapers outwards from the inside to the outside of the main body 1. Each ultrasonic sensor 34 may be configured to detect objects at positions that are difficult to detect by the imaging device 31. That is, the multiple ultrasonic sensors 34A can irradiate ultrasonic waves horizontally to objects at higher positions that are not imaged by the imaging device 31. The multiple ultrasonic sensors 34B can irradiate ultrasonic waves in the left and right direction y, which is not imaged by the imaging device 31. 【0039】 The charging terminal 32 is located on the front surface 5 in the driving direction x. The charging terminal 32 is located near the center of the front surface 5 in the left-right direction y. In the up-down direction z, the charging terminal 32 is located between the imaging device 31 and the main body recess 7. The charging terminal 32 is configured to be able to charge the battery 21 by being electrically connected to an external power supply or charging device. 【0040】The drive system 70 performs the function of driving the cleaning robot A1. The drive system 70 is located at the bottom of the main body 1 in the vertical z direction. The drive system 70 includes two drive wheels 71, front casters 73, two auxiliary casters 731, and two rear casters 74. The front casters 73, the two auxiliary casters 731, and the two rear casters 74 are driven wheels. 【0041】 The two drive wheels 71 are spaced apart on both sides in the left-right direction y, and are located approximately in the center of the main body 1 in the driving direction x. Each of the two drive wheels 71 is connected to one motor 7A. In Figures 6 and 8, the motors 7A are shown as hidden lines (dotted lines). The drive wheels 71 are rotated by the motors 7A. As a result, the cleaning robot A1 can rotate while moving forward, backward, and left and right. Each drive wheel 71 consists of two wheels aligned in the left-right direction y. Each wheel is larger than each of the front caster 73, the two auxiliary casters 731, and the two rear casters 74. 【0042】 The front wheel caster 73 is located in front of the two drive wheels 71 in the drive direction x, and is approximately in the center of the main body 1 in the left-right direction y. The two auxiliary casters 731 are located between the two drive wheels 71 and the front wheel caster 73 in the drive direction x. The two auxiliary casters 731 are spaced apart on both sides in the left-right direction y. The two rear wheel casters 74 are located behind the two drive wheels 71 in the drive direction x, and are spaced apart on both sides in the left-right direction y. 【0043】The front-wheel casters 73 and the two auxiliary casters 731 rotate about an axis extending in the left-right direction y. Each of the two rear-wheel casters 74 is attached to an axis orthogonal to the up-down direction z and rotates about the axis. Further, this axis is rotatable about the up-down direction z as the central axis. That is, in addition to the rotation of the wheel itself, the rear-wheel caster 74 can swing-rotate with a predetermined radius. Referring to FIG. 8, the positions that the rear-wheel caster 74 can take when viewed in the left-right direction y are shown. Specifically, the rear-wheel caster 74 swings about the axis O and takes a forward state 74A and a rearward state 74B. In FIG. 8, the forward state 74A is shown by a solid line and the rearward state 74B is shown by an imaginary line (two-dot chain line). 【0044】 Referring to FIG. 9, a block diagram of an exemplary cleaning robot A1 is shown. In an exemplary embodiment, the cleaning robot A1 can perform a simultaneous localization and mapping (SLAM) process of position estimation and mapping described below. 【0045】 First, the user operates the input / output interface 2C to start teaching the cleaning robot A1. After the start of teaching, the user moves the cleaning robot A1 so as to pass through a desired travel path. Specifically, the user pushes and moves the cleaning robot A1 while gripping the handle 2A on the desired travel path. At this time, the cleaning robot A1 uses the imaging device 31, the sensor system 33, and the ultrasonic sensor 34 to detect the surrounding situation (the shape and arrangement of objects such as walls and shelves). Thereby, the cleaning robot A1 specifies its own position in the map at each time point while creating a map based on the detected surrounding situation. 【0046】After finishing teaching the desired travel route, the user operates the input / output interface 2C to cause the cleaning robot A1 to finish the teaching. Finally, the cleaning robot A1 records the map of the taught travel route in the circuit unit 16. In an exemplary embodiment, the map is three-dimensional data or two-dimensional data. As an example, the taught data may include routes that were not traveled during teaching near the travel route and travel times based on a given travel speed of the cleaning robot A1. 【0047】 The cleaning robot A1 that has finished teaching is moved by the user to the vicinity of the start position of the travel route. The user may cause the cleaning robot A1 to recognize the start position with a sign displaying a two-dimensional code or the like. Then, the cleaning robot A1 receives an instruction to start cleaning from the user. The instruction to start may use the input / output interface 2C. Cleaning may be started at a time preset by the user. The cleaning robot A1 can automatically return to the stored start position. 【0048】 The cleaning robot A1 that has received the instruction to start travels autonomously along the travel route memorized during teaching. At this time, the cleaning robot A1 recognizes its own position in the created map with the detection system 30. This operation is referred to as playback. The cleaning robot A1 during playback determines an object that was not mapped during teaching as an obstacle. The cleaning robot A1 discriminates whether the obstacle is an object or a person based on mobility, shape, etc., and performs an appropriate operation. 【0049】 The cleaning robot A1 during playback further cleans the target. Specifically, by driving the brush 101 and the vacuum unit 105, dirt is collected while traveling. Additionally, the cleaning robot A1 may include a cleaning pad provided so as to contact the cleaning target surface. The cleaning pad is, for example, a mop. According to this configuration, the cleaning robot A1 can perform wiping cleaning together with or independently of the collection of dirt. 【0050】The above describes the configuration in which cleaning robot A1 performs autonomous cleaning. On the other hand, cleaning robot A1 can also perform cleaning while being operated by a user. In this case, the user instructs cleaning robot A1 to operate in manual operation mode via the input / output interface 2C. In manual operation mode, the user can perform cleaning by pushing and moving arm 2B. Even in manual operation mode, cleaning robot A1 may use the detection system 30 to detect the presence or absence of obstacles. 【0051】 In an exemplary embodiment, a step 40 is provided on the rear surface 4. The step 40 is provided so that a user can step on it with their foot. Specifically, the step 40 protrudes from the rear surface 4 in the direction of drive x. In conventional cleaning robots, if force is applied backward to tilt the main body, the main body may move backward. In contrast, with cleaning robot A1, as shown in Figure 7, by placing a foot Ft on the step 40 and pushing down the main body 1 with the handle 2A, the cleaning robot A1 can be easily tilted without moving backward. In other words, the user can easily transition the cleaning robot A1 into a tilted position. 【0052】 In the illustrated example, when viewed from the rear, step 40 is located below the center of the main body 1 in the vertical z direction. More specifically, when viewed from the rear, step 40 is located between the battery cover 43 and the dust box 102 in the vertical z direction. Step 40 is at the same height as a portion of each drive wheel 71 in the vertical z direction. Step 40 connects to the bottom surface 3 and the two side surfaces 6. Alternatively, step 40 may connect to one of the two side surfaces 6, or not to either. In plan view, step 40 has any geometric shape, such as a semicircle. In the illustrated example, the shape of step 40 is trapezoidal in plan view. 【0053】Step 40 is located within the circumference traced by the outermost part of the robot excluding step 40 during rotation. This circumference corresponds to the circle shown by the dashed line in Figure 5. With this configuration, when the cleaning robot A1 rotates, step 40 is less likely to collide with surrounding objects. 【0054】 Step 40 includes an upper step surface 401 and a lower step surface 402 that are separated from each other in the vertical direction z. The upper step surface 401 faces upward in the vertical direction z, and the user's foot Ft rests on the step 40. The upper step surface 401 is parallel to the drive direction x and the left-right direction y. Alternatively, the upper step surface 401 may be inclined, raised, or recessed. In the illustrated example, the upper step surface 401 has some irregularities. 【0055】 The step bottom surface 402 faces downward in the vertical direction z and is configured to contact the floor surface FL when the cleaning robot A1 is tilted, as shown in Figure 10. Specifically, the step bottom surface 402 is tilted so that it is located upward in the vertical direction z as it moves further away from the main body 1 in the drive direction x. With this configuration, when the cleaning robot A1 is tilted, the cleaning robot A1 can be stationary at an angle with the step bottom surface 402 in contact with the floor surface FL, as shown in Figure 10. The step bottom surface 402 is a flat surface. Alternatively, the step bottom surface 402 may be a curved surface. 【0056】 Furthermore, it is preferable that the inclined step bottom surface 402 coincides with one of the tangents of the wheels of each rear wheel caster 74. Referring to Figure 8, the rear wheel caster 74 in the forward position 74A has a tangent L. The tangent L is parallel to and coincides with the step bottom surface 402. With this configuration, a state is achieved in which both the step bottom surface 402 and the rear wheel caster 74 are in contact with the floor surface FL, and the inclined posture of the cleaning robot A1 can be stably maintained. As can be understood from the above description, the rear wheel caster 74 does not always need to have a tangent L, and it is preferable that it has a position in which the tangent L exists. 【0057】The lower surface 402 of the step may be provided with an elastic member 405. The elastic member 405 is made of, for example, rubber. This allows the impact when the lower surface 402 of the step comes into contact with the floor surface FL to be absorbed by the elastic member 405, thereby preventing damage to the floor. 【0058】 Step 40 includes a step side 403 and two notches 404. The step side 403 is located behind in the drive direction x. Preferably, the step side 403 is linear when viewed from above in the vertical direction z (i.e., has a linear boundary above). The step side 403 contacts the floor surface FL when the cleaning robot A1 is tilted further than its inclined position, approaching horizontal. Therefore, if the step side 403 is linear, the cleaning robot A1 is less likely to sway from side to side and can maintain a stable tilted position. The two notches 404 are located at each end of the step side 403 in the left-right direction y. With this configuration, the portion protruding from the center of rotation of the cleaning robot A1 is reduced compared to when the step 40 is rectangular. With this configuration, the risk of the cleaning robot A1 getting caught on surrounding objects when it rotates is reduced. 【0059】 The cleaning robot A1 can maintain an inclined position without requiring user support. Figure 10 shows the cleaning robot A1 stationary in an inclined position (inclined state). In this state, the user can access the bottom surface 3 of the cleaning robot A1. Therefore, in the state shown in Figure 10, the user can operate the bottom surface 3 of the cleaning robot A1 to maintain the brush 101 and dust box 102. 【0060】Furthermore, for more detailed maintenance, the user may tilt the cleaning robot A1 until it is horizontal. Figure 11 shows the cleaning robot A1 stationary in a near-horizontal position (horizontal state). In the horizontal state, the cleaning robot A1 has two protrusions 4a in contact with the floor surface FL in addition to the step side surface 403. In this state, the bottom surface 3 faces forward in the drive direction x, making it easier for the user to access the bottom surface 3 of the cleaning robot A1. In the illustrated example, in the horizontal state, the cleaning robot A1 is inclined away from the floor surface FL from the top surface 2 to the bottom surface 3 because the step side surface 403 is located behind the tip of the protrusion 4a in the drive direction x. Alternatively, the horizontal state of the cleaning robot A1 can have the direction of inclination reversed, or be parallel to the floor surface FL. That is, the protrusions 4a may protrude behind the step 40, or they may protrude to the same depth as the step 40. 【0061】 As shown in Figure 10, during the process of tilting the cleaning robot A1 horizontally, the step 40 comes into contact with the floor surface FL, allowing the main body 1 to be stopped in an inclined position. Therefore, the user can temporarily stop the cleaning robot A1 in a stable state during the process of tilting it horizontally as shown in Figure 11. As a result, even users with limited physical strength can tilt the cleaning robot A1 with confidence. Note that Figure 11 is an example illustrating the inclined and horizontal states and is not intended to limit the form of the cleaning robot A1. 【0062】 To achieve the inclined state of the cleaning robot A1, in this embodiment, the lower surface 402 of the step 40 includes an inclined surface relative to the floor surface FL. In the example shown in Figure 10, the lower surface 402 of the step is in contact with the floor surface FL. When viewed from above, the lower surface 402 of the step coincides with the center of gravity of the cleaning robot A1. Furthermore, it is preferable that the center of the lower surface 402 of the step coincides with the center of gravity of the cleaning robot A1 when viewed from above. Also, although Figure 10 shows the case where the arm 2B is integrated, it is preferable that the relationship between the lower surface 402 of the step and the center of gravity of the cleaning robot A1 satisfies the above condition even when the arm 2B is in a detached state. 【0063】A1: Cleaning robot, 1: Main body, 100: Dust collection assembly, 101: Brush, 102: Dust box, 103: Duct, 104: Chamber, 105: Vacuum unit, 106: Exhaust port, 14: Shelf, 15: Circuit board box, 16: Circuit section, 2: Top view, 200: Operating section, 2A: Handle, 2Aa: Horizontal bar, 2Ab: Vertical bar, 2B: Arm, 2C: Input / output interface, 2D: Emergency stop button, 3: Bottom view, 30: Detection system, 31: Imaging device, 32: Charging terminal, 33: Sensor system, 34A, 34B : Ultrasonic sensor, 35A, 35B: Cliff sensor, 4: Rear, 40: Step, 401: Top of step, 402: Bottom of step, 403: Side of step, 404: Notch, 41: Battery housing, 43: Battery cover, 5: Front, 6: Side, 6A: Gripping hole, 7: Main body recess, 70: Drive system, 71: Drive wheel, 72: Drive motor, 73: Front wheel caster, 74: Rear wheel caster, 7A, 7B: Motor, 8: Front bumper, 9: Side bumper, FL: Floor, Ft: Foot, x: Drive direction, y: Left / right direction, z: Up / down direction

Claims

1. A cleaning robot comprising: a body having steps; a handle; the body having a bottom surface facing the surface to be cleaned; a top surface separated from the bottom surface in the vertical direction; and a rear surface located behind the driving direction of the cleaning robot and interposed between the bottom surface and the top surface; the handle is provided on the top surface; and the steps protrude from the rear surface toward the rear in the driving direction.

2. The cleaning robot according to claim 1, wherein the cleaning robot rotates around an axis extending in the vertical direction, and the step is provided within the circumference traced during the rotational movement, with the outermost part other than the step being located within the circumference traced during the rotational movement.

3. The cleaning robot according to claim 1, wherein the step has a step side located behind the drive direction, and the step side is linear when viewed from above.

4. The cleaning robot according to claim 3, wherein the step has a notch at the end of the side surface of the step in a direction perpendicular to the vertical direction.

5. The cleaning robot according to any one of claims 1 to 4, further comprising wheels, wherein the step includes a lower surface of the step facing the surface, and any tangent of the wheel coincides with the lower surface of the step.

6. The cleaning robot according to claim 5, wherein an elastic member is provided on the lower surface of the step.

7. The cleaning robot according to any one of claims 1 to 4, wherein the handle is annular when viewed from above.

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