Floor Cleaning Robot

Abstract

To provide an autonomous traveling type wagon and a floor cleaning robot using the autonomous traveling type wagon, which can secure stable grounding performance with respect to concavity and convexity of a travel surface, such as a floor, with a simple structure.SOLUTION: An autonomous traveling type wagon AC comprises: a drive wheel DW which has a two-wheel configuration; a drive wheel frame DF which fixes the drive wheel DW; a driven wheel TW which has a two-wheel configuration; a driven wheel frame TF which fixes the driven wheel TW; and an attaching part AT which rotatably attaches the driven wheel frame TF with respect to the drive wheel frame DF. A floor cleaning robot 100 includes the autonomous traveling type wagon AC, and a cleaning pad 50, which is a pad part for floor cleaning, attached to a bottom of the drive wheel frame DF.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an autonomously traveling cart that is equipped with drive wheels and is self-propelled, and a floor cleaning robot that utilizes the autonomously traveling cart. [Background technology]

[0002] Known examples of devices that are equipped with drive wheels and therefore can travel autonomously include a three-wheeled vacuum cleaner consisting of driven wheels and drive wheels (see Patent Document 1) and an unmanned guided vehicle with a four-wheel structure (see Patent Document 2).

[0003] However, for example, in the case of a three-wheel configuration consisting of one driven wheel and two drive wheels as in the above Patent Document 1, due to restrictions on the mounting position of the wheels, when a rotating pad for cleaning is provided in an autonomous floor cleaning robot, for example, a space-saving layout may be difficult in relation to the arrangement of the wheels depending on the configuration of the rotating pad. Furthermore, in order to avoid the above situation, for example, a four-wheel structure as in the above Patent Document 2 may be used to arrange the wheels at the four corners and ensure space for the rotating pad, but in the case of a four-wheel structure, one of the wheels is likely to lift up due to unevenness of the running surface such as the floor surface, which may cause the drive wheels to slip and make it difficult to stabilize the running. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-144055 A [Patent Document 2] JP 2019-067315 A Summary of the Invention

[0005] The present invention has been made in consideration of the above-mentioned points, and aims to provide an autonomously traveling cart and a floor cleaning robot using an autonomously traveling cart that can ensure stable ground contact performance against unevenness of the traveling surface such as a floor with a simple configuration.

[0006] To achieve the above-mentioned objective, an autonomously traveling cart includes a two-wheel drive wheel, a drive wheel frame to which the drive wheels are fixed, a two-wheel driven wheel, a driven wheel frame to which the driven wheels are fixed, and a mounting portion to rotatably mount the driven wheel frame to the drive wheel frame.

[0007] In the above-mentioned autonomous traveling cart, even if it has a total of four wheels, with two driving wheels and two driven wheels, the driven wheel frame that fixes the driven wheels is attached in a rotatable state to the driving wheel frame that fixes the driving wheels, thereby ensuring stable ground contact performance against unevenness of the traveling surface such as a floor with a simple configuration.

[0008] In a specific aspect of the present invention, the driving wheel frame is a main frame that supports the driving source of the driving wheels together with the load, and the driven wheel frame fixes each wheel of the driven wheels at both ends of a rod-shaped member, and at least one wheel of the driven wheels touches the ground depending on the degree of unevenness of the road surface on which the vehicle is traveling. In this case, even if the road surface is uneven, the driven wheel frame rotates relative to the main frame, and the wheels constituting the driven wheels can maintain a state of touching the road surface.

[0009] According to another aspect of the present invention, a rotation limiting mechanism is provided that limits the range of rotation of the driven wheel frame by the mounting portion. In this case, by providing an appropriate rotation limit, stable rotation operation can be maintained.

[0010] In yet another aspect of the present invention, the rotation limiting mechanism includes an elastic member that connects the driving wheel side pin provided on the driving wheel frame and the driven wheel side pin provided on the driven wheel frame while allowing the pins to be displaced relative to each other. In this case, it is possible to appropriately limit rotation while allowing displacement due to rotation with a simple configuration.

[0011] In yet another aspect of the invention, the driven wheel is rotatable relative to a horizontal plane.

[0012] A floor cleaning robot for achieving the above-mentioned object is a floor cleaning robot equipped with any of the autonomously traveling carts described above, and equipped with a pad portion for cleaning floor surfaces that is attached to the bottom surface of the drive wheel frame.

[0013] In the above floor cleaning robot, by providing an autonomous traveling cart, stable ground contact performance can be ensured with a simple configuration even when the traveling surface is uneven, such as a floor. [Brief description of the drawings]

[0014] [Figure 1] 1A to 1E are conceptual diagrams for explaining an autonomous traveling vehicle according to a first embodiment. [Diagram 2] FIG. 1A is a conceptual diagram showing an example of how an autonomous traveling vehicle travels, and FIG. 1B is a diagram of a comparative example to FIG. [Diagram 3] 1A and 1B are conceptual diagrams for explaining one configuration example of a floor cleaning robot equipped with an autonomous traveling cart. [Figure 4] FIG. 2 is a block diagram for explaining a configuration example of a floor cleaning robot. [Diagram 5] 1A to 1C are conceptual diagrams showing an autonomous traveling cart of a floor cleaning robot and its surrounding parts. [Figure 6] FIG. 13 is a conceptual diagram showing a comparative example of a floor cleaning robot. [Figure 7] 13(A) to 13(D) are conceptual diagrams for explaining the structure of a driven wheel frame according to a second embodiment. [Figure 8] 6(A) to 6(C) are conceptual diagrams for explaining a rotation limiting mechanism. [Figure 9] 13(A) to 13(C) are conceptual diagrams for explaining a rotation limiting mechanism provided in a floor cleaning robot including an autonomous traveling cart according to one modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [First embodiment] An example of the autonomous traveling vehicle according to the first embodiment will be described below with reference to Fig. 1. Fig. 1(A) is a side view conceptually showing the autonomous traveling vehicle AC according to this embodiment, and Fig. 1(B) is a plan view. Figs. 1(C) to 1(E) are front views showing how the autonomous traveling vehicle AC travels. In each drawing, directions are shown in a right-handed XYZ coordinate system, with the forward direction of the autonomous traveling vehicle AC being the +Z direction, the upward direction being the +Y direction, and the left and right directions being the ±X directions.

[0016] As shown in Fig. 1(A) and other figures, the autonomous traveling vehicle AC according to this embodiment includes a traveling device 10, a traveling control unit 20, a driving wheel frame DF, a driven wheel frame TF, and a mounting unit AT. The traveling device 10 includes a first traveling unit 10A, a second traveling unit 10B, and a driven wheel unit 10C. The autonomous traveling vehicle AC drives the first and second traveling units 10A and 10B under the control of the traveling control unit 20, thereby enabling autonomous traveling.

[0017] Of the traveling device 10, the first traveling unit 10A has a right wheel WR, which is one of the two-wheel drive wheels DW, and a right wheel drive unit RD composed of a motor for driving the right wheel WR. Similarly, the second traveling unit 10B has a left wheel WL, which is the other of the two-wheel drive wheels DW, and a left wheel drive unit LD composed of a motor for driving the left wheel WL. That is, the first traveling unit 10A is responsible for driving rotation of the right side of the pair of left and right rear wheels, and the second traveling unit 10B is responsible for driving rotation of the left side of the pair of left and right rear wheels. At this time, the wheel drive units RD and LD function as a drive source for the drive wheels DW. Furthermore, the first and second traveling units 10A and 10B are equipped with encoders RE and LE that measure the rotation of the wheels WR and WL. In the traveling device 10, the first traveling unit 10A and the second traveling unit 10B are driven independently of each other, so that the autonomous traveling cart AC can, for example, rotate (turn) in addition to moving forward and backward. That is, the first running unit 10A and the second running unit 10B rotate the pair of left and right drive wheels DW in the same direction to enable forward and backward movement, and the pair of left and right drive wheels DW rotate in opposite directions to each other to enable rotation. By appropriately changing the direction of rotation by the traveling device 10, it may be possible to further reverse, and the direction of rotation (turning) may also be rotatable in both directions. In addition, the encoders RE and LE measure the rotation of the right wheel WR and the left wheel WL, respectively, and output the measurement results to the traveling control unit 20. In addition, the right wheel WR and the left wheel WL, which are the two-wheel drive wheels DW, are fixed to the driving wheel frame DF in a rotatable state.

[0018] Of the traveling device 10, the driven wheel section 10C includes a right wheel FWa and a left wheel FWb that constitute a two-wheel driven wheel configuration TW, and the right wheel FWa and the left wheel FWb are fixed to the driven wheel frame TF in a rotatable state.

[0019] As described above, the autonomous traveling cart AC has a total of four wheels, consisting of two drive wheels DW (WR, WL) and two driven wheels TW (FWa, FWb). In general, in a total of four wheels, one of the wheels is more likely to float than in a total of three wheels. In contrast, in this embodiment, such a problem is solved by providing the driven wheel frame TF and the like. This will be described in detail with reference to FIG. 2.

[0020] Returning to Figure 1(A) etc., the traveling control unit 20 of the autonomous traveling cart AC is composed of, for example, various circuit boards, etc., and is connected to each part of the traveling device 10. It outputs various command signals such as drive signals to the wheel drive units RD, LD of the traveling device 10 and obtains measurement results from the encoders RE, LE, thereby controlling the traveling of the autonomous traveling cart AC while grasping the traveling position of the autonomous traveling cart AC, etc.

[0021] As described above, the drive wheel frame DF is a support member for fixing the two-wheel drive wheels DW. In the illustrated example, the drive wheel frame DF is formed of a housing-like member and stores various parts such as the travel control unit 20 inside. The structure of the drive wheel frame DF can be various forms other than the above example. For example, it can be formed of a plate-like member and various parts can be placed on the plate-like member, or various parts can be attached to the lower part of the drive wheel frame DF. As described above, the drive wheel frame DF functions as a main body frame that can form the main body part MM of the autonomously traveling cart AC that is integrated by fixing and supporting each part of the device.

[0022] As described above, the driven wheel frame TF is a support member for fixing the two-wheel driven wheels TW. In the illustrated example, the driven wheel frame TF has a rod-shaped member as a main body, and the right wheel FWa and the left wheel FWb constituting the two-wheel driven wheels TW are fixed at both ends of the rod-shaped member. In this case, the driven wheel frame TF functions as a member for integrating the two-wheel driven wheels TW. As a result, as shown in FIG. 1(D) and FIG. 1(E), for example, the driven wheel frame TF can be inclined according to the degree (degree of height) of an obstacle (unevenness) OB on the road surface GN, which is the traveling road surface, so that at least one of the right wheel FWa and the left wheel FWb constituting the driven wheels TW can be grounded.

[0023] The attachment part AT is a member for rotatably attaching the driven wheel frame TF to the driving wheel frame DF. In the illustrated example, the driven wheel frame TF and the driving wheel frame DF are connected by a cylindrical member CC extending in the traveling direction, i.e., the Z direction, and as shown in Fig. 1(C) to Fig. 1(E), the driven wheel frame TF is in a state of being rotatable about the cylindrical member CC. As a result, even if an obstacle (unevenness) OB is present on the road surface GN on which the autonomous traveling vehicle AC travels, the autonomous traveling vehicle AC can overcome the obstacle OB by rotating the driven wheel frame TF together with the two-wheeled driven wheel TW associated therewith. In addition, the driven wheel frame TF and the two-wheeled driven wheel TW that rotate integrally about the axis of the cylindrical member CC as described above are regarded as a movable part MA with respect to the main body part MM. In other words, the attachment part AT is a member for rotatably attaching the movable part MA to the main body part MM. In addition, in the above case, in terms of weight, the main body part MM side including the driving wheel frame DF is relatively heavier, and the movable part MA side including the driven wheel frame TF is lighter, making it easier for the movable part MA to rotate relative to the main body part MM.

[0024] As described above, the movable part MA is driven to rotate relative to the main body part MM, that is, the movable part MA side is capable of changing its position relative to the main body part MM, so that even if the movable part MA tilts, the main body part MM does not necessarily tilt together with the movable part MA, and both the right wheel WR and the left wheel WL constituting the driving wheels DW can be maintained on the main body part MM side in a state in which they are placed on the road surface GN. On the other hand, on the movable part MA side, the driven wheel frame TF rotates to maintain a state in which at least one of the right wheel FWa and the left wheel FWb constituting the driven wheels TW is in contact with the ground. In other words, the autonomously traveling cart AC can travel stably by maintaining a state in which two points of the right wheel WR and the left wheel WL and at least one point on the movable part MA side are in contact with the ground.

[0025] In order to smoothly perform the above rotational movement, it is possible to consider, for example, making the driven wheel frame TF flexible to a certain extent, making the driven wheels TW elastic (contraction and expansion), providing suspensions, etc. The same is also possible for the drive wheel frame DF and drive wheels DW on the main body part MM side.

[0026] Hereinafter, the operation of the autonomous traveling cart AC during traveling will be described with reference to Fig. 2. Fig. 2(A) is a conceptual diagram showing an example of the traveling state of the autonomous traveling cart AC, and Fig. 2(B) is a diagram of a comparative example to Fig. 2(A). Note that the autonomous traveling cart ACx of the comparative example shown in Fig. 2(B) differs from the present embodiment illustrated in Fig. 2(A) in that all wheels in a total four-wheel configuration consisting of two driving wheels DW (WR, WL) and two driven wheels TW (FWa, FWb) are attached to one large frame FR.

[0027] In the above case, first, in the autonomous traveling vehicle AC according to this embodiment, as shown in Fig. 2(A) and as described with reference to Fig. 1(E) etc., if there is an obstacle OB on the right side of the autonomous traveling vehicle AC in the forward direction (+Z direction) of the autonomous traveling vehicle AC, when the autonomous traveling vehicle AC reaches the location of the obstacle OB, first, the right wheel FWa of the two-wheeled driven wheels TW runs over the obstacle OB, and as the autonomous traveling vehicle further advances, the movable part MA rotates relative to the main body part MM, so that the movable part MA tilts and becomes able to overcome the obstacle OB. At this time, the main body part MM side is maintained in a horizontal state without tilting, that is, a state in which both the right wheel WR and the left wheel WL are placed on the road surface GN, until the drive wheel DW reaches the obstacle OB.

[0028] In contrast, in the case of the autonomous traveling vehicle ACx shown in Fig. 2(B) as a comparative example, if an obstacle OB is present in a similar position, as shown in the figure, the right wheel FWa runs over the obstacle OB and the entire autonomous traveling vehicle ACx including the frame FR tilts at the same time. As a result, the right wheel WR, i.e., the drive wheel DW, which is on the same side as the right wheel FWa, also tilts, and as shown in the figure, there is a high possibility that the right wheel WR will lift off the road surface GN. Note that the same thing can also occur on the left side, i.e., the left wheel WL constituting the drive wheel DW, if there is an obstacle OB.

[0029] As described above, if the wheels WR, WL constituting the drive wheels DW are lifted and spinning freely, for example, the drive wheels DW may slip, making it impossible to stabilize the running, or an error may occur in grasping the running position of the autonomous running cart AC based on the measurement results from the encoders RE, LE. In contrast, in this embodiment, the above-mentioned configuration is used to avoid or suppress such a situation.

[0030] As described above, the autonomous traveling cart AC according to this embodiment includes the two-wheel drive wheels DW, the drive wheel frame DF to which the drive wheels DW are fixed, the two-wheel drive wheels TW, the drive wheel frame TF to which the drive wheels TW are fixed, and the mounting part AT to which the drive wheel frame TF is rotatably mounted to the drive wheel frame DF. Even if the autonomous traveling cart AC has a total of four wheels, including the two-wheel drive wheels DW and the two-wheel drive wheels TW, as described above, the drive wheel frame TF to which the drive wheels TW are fixed is rotatably mounted to the drive wheel frame DF to which the drive wheels DW are fixed, thereby ensuring stable ground contact performance against unevenness of the running surface such as an obstacle OB on the floor (road surface GN) with a simple configuration.

[0031] Hereinafter, an example of the floor cleaning robot 100 equipped with the autonomously traveling cart AC according to this embodiment will be described with reference to FIG. 3 and the like. FIG. 3(A) is a conceptual side view for explaining an example of the configuration of the floor cleaning robot 100 equipped with the autonomously traveling cart AC, and FIG. 3(B) is a bottom view. Also, FIG. 4 is a block diagram for explaining an example of the configuration of the floor cleaning robot 100. Furthermore, FIG. 5(A) to FIG. 5(C) are conceptual diagrams showing the autonomously traveling cart AC of the floor cleaning robot 100 and its surrounding parts, where FIG. 5(A) is a side view, FIG. 5(B) is a bottom view, and FIG. 5(C) is a front view.

[0032] For example, as shown in FIG. 3(A) and FIG. 3(B), the floor cleaning robot 100 according to the present embodiment includes a cleaning pad 50 for cleaning and a cleaning pad drive control unit PD in addition to the components constituting the autonomously traveling cart AC. In addition, although not shown, the robot may include a distance measuring device for grasping the surrounding situation, a water tank, a water sprinkling device, and even a drainage recovery device to enable cleaning while sprinkling water. Furthermore, the robot may have a device for handling map information, store the travel route in advance, and set the cleaning route in advance. Each of these devices can be stored in the housing CS of the floor cleaning robot 100. In the illustrated example, the housing CS is placed on the drive wheel frame DF, which is the main body frame. From another perspective, the drive wheel frame DF supports the wheel drive units RD and LD, which are the drive sources of the drive wheels arranged on the lower side, together with the objects stored in the housing CS, thereby functioning as the main body frame of the autonomously traveling cart AC and the floor cleaning robot 100.

[0033] In order to enable traveling in cooperation with each of the above-mentioned parts, the traveling control unit 20 in the floor cleaning robot 100 cooperates with, for example, the cleaning pad drive control unit PD in addition to each part of the traveling device 10. These will be described later with reference to the block diagram shown in FIG. 4. In addition, in the example shown in FIG. 3(A) and the like, various circuits including the traveling control unit 20 are integrated into a control unit CR. That is, the control unit CR is composed of, for example, one or more various circuit boards, and controls various operations of the floor cleaning robot 100.

[0034] Among the components constituting the floor cleaning robot 100, the cleaning pad 50 and the cleaning pad drive controller PD, which are the main components for cleaning the floor, will be described below.

[0035] The cleaning pad 50 is a disk-shaped member attached to the underside of the drive wheel frame DF, which is the main body frame of the autonomous traveling cart AC, and comes into contact with the floor surface to be cleaned, i.e., the road surface GN, and is a pad part for cleaning the floor surface that rotates while in contact with the road surface (floor surface) GN during cleaning. In this example, the cleaning pad 50 is rotated in one direction about the axis part XA of the cleaning pad 50, for example as shown by the arrow A1 in Fig. 3(B), to polish the road surface (floor surface) GN.

[0036] The cleaning pad drive controller PD is composed of, for example, various circuit boards and the like, and is connected to the travel controller 20 and also to the cleaning pad 50. The cleaning pad drive controller PD controls the drive of the cleaning pad 50 according to the travel situation in accordance with a command signal from the travel controller 20.

[0037] Hereinafter, a configuration example of the above-mentioned floor cleaning robot 100 will be described with reference to the block diagram shown in Fig. 4. In particular, a portion of the floor cleaning robot 100 related to the travel control operation in the control unit CR will be described. In the illustrated example, the main control unit MP, which is a main body part of the control unit CR that is composed of a CPU or the like and is responsible for overall operation control of each part of the floor cleaning robot 100, is provided as a main part of the travel control unit 20. That is, in this example, the travel control unit 20 is directly or indirectly connected to each part of the floor cleaning robot 100, and performs various overall operation processing for floor cleaning while controlling the travel.

[0038] To achieve the above aspect, in the illustrated example, the traveling control unit 20 includes a drive adjustment unit DA for adjusting the drive of the traveling device 10, in addition to a main control unit MP configured with a CPU and the like.

[0039] The main control unit MP is connected to each component of the traveling device 10 and also to the cleaning pad drive control unit PD, and controls the driving of the cleaning pad according to the traveling state as well as the traveling control. The main control unit MP also includes a traveling position confirmation unit DC that confirms the measurement results. The traveling position confirmation unit DC confirms the traveling position based on the measurement results of the left and right encoders RE, LE provided corresponding to the left and right wheels WR, WL (driving wheels DW).

[0040] The main control unit MP controls the drive of each wheel drive unit RD, LD via the drive adjustment unit DA to control the traveling of the traveling device 10. At this time, the traveling device 10 adjusts the driving state (rotation speed, i.e., traveling speed, etc.) of each wheel WR, WL constituting the driving wheel DW based on the result of position confirmation by the traveling position confirmation unit DC. In addition, in conjunction with these, the driving state of the cleaning pad 50 (pad rotation speed, etc.) is adjusted.

[0041] As described above, each part of the floor cleaning robot 100 cooperates with each other to perform floor cleaning operations while detecting its own position during its travel.

[0042] Hereinafter, the structure of the autonomous traveling cart AC and its surroundings of the floor cleaning robot 100 will be described with reference to FIG. 5(A) and other figures. In FIG. 5(A) to FIG. 5(C), only the drive wheel frame DF, the driven wheel frame TF, the mounting part AT connecting them, the traveling device 10, and the configuration of the lower surface side of the drive wheel frame DF are omitted. In the illustrated example, the drive wheel frame DF is a plate-shaped member, and each part stored in the housing CS (see FIG. 3 and other figures) is placed on the drive wheel frame DF as a placement object. Meanwhile, a cleaning pad 50 for cleaning is provided on the lower part of the drive wheel frame DF in addition to each part constituting the traveling device 10, for example. In other words, the cleaning pad 50 is a pad part for cleaning the floor surface that is attached to the bottom surface of the drive wheel frame DF.

[0043] In the illustrated example, the mounting part AT connects a first connection part CN1 as a convex part provided on the driving wheel frame DF and a second connection part CN2 as a concave part provided in the driven wheel frame TF with a cylindrical pin PN, and the driven wheel frame TF is rotatable about the pin PN extending in the Z direction as an axis. In the illustrated example, the pair of left and right driven wheels FWa, FWb are attached and fixed to the bottom surface of the driven wheel frame TF to have a caster-like structure and are rotatable on a horizontal plane.

[0044] Here, in the case where the cleaning pad 50 is attached to the bottom side of the autonomous traveling cart AC of the floor cleaning robot 100, more specifically, to the lower surface of the drive wheel frame DF as in this embodiment, as is particularly clear from Fig. 5(B), it can be seen that the positional relationship between the cleaning pad 50 and each wheel WR, WL, FWa, FWb on the lower surface or bottom surface part is important in determining the size of the entire device and the size of the cleaning pad 50. In this embodiment, since it has a total of four wheels, as shown in the figure, the four wheels WR, WL, FWa, FWb can be arranged at the four corners of the rectangular bottom surface part defined by the lower surfaces of the drive wheel frame DF and the driven wheel frame TF, so that the circular cleaning pad 50 can be arranged over as large an area as possible relative to the entire device.

[0045] In contrast, for example, as shown in the side view and bottom view of Comparative Example α1 in FIG. 6, a three-wheel configuration with two driving wheels WR and WL and one driven wheel FW has the advantage that the wheels are less likely to float compared to a four-wheel configuration, but the diameter R1 of the cleaning surface is smaller than the body width W1 and body length H1. This is because the driven wheel FW cannot be placed at one of the four corners from the viewpoint of stabilization. For this reason, if the diameter R1 of the cleaning surface is to be increased, the body length H1 must also be increased from the state shown in Comparative Example α1, as shown in the side view and bottom view of Comparative Example α2 in FIG. 6. In other words, in the case of a three-wheel configuration, it may be difficult to achieve a space-saving layout in relation to the arrangement of the wheels WR, WL, and FW. In contrast, as shown in the side view and bottom view of Comparative Example α3 in FIG. 6, a four-wheel configuration with two driving wheels WR and WL and two driven wheels FWa and FWb can be considered to increase the diameter R1 of the cleaning surface while achieving compactness without increasing the body length H1. However, in a configuration in which four wheels WR, WL, FWa, and FWb are provided on one frame FR, as in comparison example α3, there is a possibility that the wheels WR, WL, FWa, and FWb, in particular the drive wheels WR and WL, may float, as explained with reference to Figure 2(B), for example.

[0046] In contrast, in this embodiment, the autonomous traveling cart AC is used to configure the floor cleaning robot 100. This allows the adoption of a large circular cleaning pad 50 while realizing stable running. From another perspective, this can also be said to make it possible to miniaturize the entire device relative to the cleaning pad 50.

[0047] In addition, within the range where interference with the wheels WR, WL, FWa, and FWb can be avoided, the cleaning pad 50 can be made, for example, large enough to fit just to the edge of the rectangular bottom surface or to extend partially beyond it, making it possible to clean every corner of the floor surface.

[0048] As described above, the floor cleaning robot 100 according to this embodiment includes the autonomous traveling cart AC and the cleaning pad 50, which is a pad portion for cleaning the floor surface attached to the bottom surface of the drive wheel frame DF. In this case, the floor cleaning robot 100 includes the autonomous traveling cart AC, so that the floor cleaning robot 100 can ensure stable ground contact performance against unevenness of the road surface GN, which is the traveling surface such as the floor surface, with a simple configuration.

[0049] Second Embodiment Hereinafter, an example of an autonomous traveling cart according to the second embodiment and a floor cleaning robot equipped with the same will be described with reference to FIG. 7 and the like. The autonomous traveling cart AC according to this embodiment and the floor cleaning robot 100 equipped with the same are different from those of the first embodiment in that a rotation limiting mechanism RL for limiting the rotation range of the driven wheel frame TF by the mounting part AT is provided. However, other points are similar to those of the first embodiment, so illustrations and descriptions of the autonomous traveling cart AC and the floor cleaning robot 100 will be omitted. In this embodiment, the rotation limiting mechanism RL, which is different from the first embodiment, is related to the autonomous traveling cart AC of the floor cleaning robot 100, so this is not only an embodiment of the floor cleaning robot 100 but also an embodiment of the autonomous traveling cart AC.

[0050] FIG. 7(A) is a conceptual front view for explaining the structure of the driven wheel frame TF of the autonomous traveling cart AC having a rotation limiting mechanism RL, and FIG. 7(B) is a front view showing an example of the driven wheel frame TF in a tilted state when climbing over an obstacle OB. Also, FIG. 7(C) and FIG. 7(D) are partially enlarged views of FIG. 7(A) and FIG. 7(B). Furthermore, FIG. 8(A) is a conceptual plan view showing the rotation limiting mechanism RL, and FIG. 8(B) and FIG. 8(C) are partially enlarged views of the rotation limiting mechanism RL in FIG. 7(C) and FIG. 7(D). In FIG. 8(B) and FIG. 8(C), the horizontal reference line HS is shown by a dashed line to show the state of inclination by comparison.

[0051] First, as shown in FIG. 7(A) and other figures, in this embodiment, a pair of rotation limiting mechanisms RL are provided on both ends of the rod-shaped driven wheel frame TF, symmetrically about the pin PN constituting the mounting part AT. For example, as shown in FIG. 7(B), when the driven wheel frame TF is tilted by an obstacle (unevenness) OB, the rotation limiting mechanism RL functions as a stopper to allow the driven wheel frame TF to tilt to a certain extent and to prevent it from tilting beyond a certain extent. That is, first, as shown in FIG. 7(C) and FIG. 8(B), when the driven wheel frame TF is not tilted, movement is permitted. On the other hand, as shown in FIG. 7(D) and FIG. 8(C), when the driven wheel frame TF is tilted to a certain extent, further tilting is restricted. In addition, in the mounting part AT, in order to maintain the posture shown in FIG. 7(A), FIG. 7(B) or FIG. 8(B) when traveling on a horizontal plane, a neutral position maintaining mechanism may be provided using, for example, a spring mechanism to hold the mounting part AT vertically.

[0052] An example of the configuration of the rotation limiting mechanism RL for performing the above-mentioned functions will be described below mainly with reference to Fig. 8(A). As shown in Fig. 8(A) and other figures, the rotation limiting mechanism RL has a driving wheel side pin DP provided on the driving wheel frame DF, a driven wheel side pin TP provided on the driven wheel frame TF, and a ring-shaped elastic member (rubber band) EP connecting them. In other words, the elastic member EP connects the driving wheel side pin DP and the driven wheel side pin TP while allowing them to be displaced relatively. Note that, as shown in Figs. 8(B) and 8(C), the driven wheel frame TF is provided with an insertion hole HL for inserting the driving wheel side pin DP extending from the driving wheel frame DF.

[0053] First, when the driven wheel frame TF is not tilted as shown in Fig. 8(B) or Fig. 7(C), the driving wheel side pin DP and the driven wheel side pin TP are close to each other, so that the elastic member EP does not apply a large force to them, and the driven wheel frame TF is in a rotatable state. On the other hand, when the driven wheel frame TF is tilted to a certain extent as shown in Fig. 8(C) or Fig. 7(D), the driving wheel side pin DP and the driven wheel side pin TP are farther apart, so that the elastic member EP applies a force to bring them closer together. In other words, the rotation of the driven wheel frame TF is restricted. As described above, in the rotation restriction mechanism RL with a simple configuration, by appropriately determining the strength of the elastic member EP and the relative position of the driving wheel side pin DP and the driven wheel side pin TP, it is possible to appropriately restrict the rotation while allowing the displacement due to the rotation of the driving wheel frame DF.

[0054] The rotation limiting mechanism RL is not limited to the above example, and various modified examples are applicable. For example, as shown in one modified example in Figures 9(A) to 9(C) corresponding to Figures 8(A) to 8(C), it is possible to provide a driving wheel side pin DP and an insertion hole HL for inserting the driving wheel side pin DP without using an elastic member EP or a driven wheel side pin TP, and to restrict rotation by having the driving wheel side pin DP hit the side of the insertion hole HL.

[0055] 〔others〕 The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the present invention.

[0056] First, the mounting part AT is not limited to the above and may be in other forms as long as the required rotational movement is obtained. In the above-mentioned form, it is considered to be an effective form to provide only accurate rotational movement without providing play or the like with respect to the cylindrical shaft.

[0057] In addition, in the above, the travel position is calculated by the encoders RE and LE, but this is not limiting, and position measurement may be performed in combination with various sensors, etc. For example, in the floor cleaning robot 100, if the action due to the rotation of the cleaning pad 50 affects the position fluctuation, the position may be grasped taking this into account.

[0058] In addition, in the above, the autonomous traveling cart AC shown in FIG. 1 and the like is configured to rotate independently on the left and right sides, but it is also possible to configure them to be driven integrally.

[0059] Furthermore, various aspects of the floor cleaning robot 100 are possible. For example, the present application may be applied to a dry floor cleaning robot that does not have a water tank or the like in order to make the robot smaller and thinner.

[0060] In addition, the above describes the case where the autonomously traveling cart AC is applied to a floor cleaning robot (cleaning robot) 100 that moves while measuring its traveling position, but it is also possible to apply the present application to various moving bodies (mobile robots, transport robots) that require precise movement similar to the floor cleaning robot 100. [Explanation of symbols]

[0061] 10...Traveling device, 10A...First traveling part, 10B...Second traveling part, 10C...Driven wheel part, 20...Travel control part, 50...Cleaning pad, 100...Floor cleaning robot (cleaning robot), A1...Arrow, AC...Autonomous traveling cart, ACx...Autonomous traveling cart, AT...Mounting part, CC...Cylindrical member, CN1...First connection part, CN2...Second connection part, CR...Control part, CS...Housing, DA...Drive adjustment part, DC...Travel position confirmation part, DF...Drive wheel frame (main body frame), DP...Drive wheel side pin, DW...Drive wheel, EP...Elastic member (rubber band), FR...Frame, F W... driven wheel, FWa... right wheel (driven wheel), FWb... left wheel (driven wheel), GN... road surface (floor surface), H1... body length, HL... insertion hole, LD... left wheel drive unit, MA... moving part, MM... body part, MP... main control unit, OB... obstacle (unevenness), PD... cleaning pad drive control unit, PN... pin, R1... diameter, RD... right wheel drive unit, RE, LE... encoder, RL... rotation limiting mechanism, TF... driven wheel frame, TP... driven wheel side pin, TW... driven wheel, W1... body width, WL... left wheel (driven wheel), WR... right wheel (driven wheel), XA... shaft part, α1 to α3... comparison example

Claims

1. A two-wheel drive wheel configuration; A drive wheel frame for fixing the drive wheel; A two-wheel driven wheel; A driven wheel frame for fixing the driven wheel; a mounting portion extending in a traveling direction and configured to rotatably mount the driven wheel frame to the driving wheel frame; a rotation limiting mechanism that limits a rotation range of the driven wheel frame by the mounting portion; a floor cleaning pad portion attached to the bottom surface of the driving wheel frame so as to protrude partially toward the bottom surface side of the driven wheel frame and having a width larger than the distance between the two wheels constituting the driving wheels; A floor cleaning robot comprising:

2. The drive wheel frame is a main body frame that supports a drive source of the drive wheel together with a load, 2. The floor cleaning robot according to claim 1, wherein the driven wheel frame fixes the wheels of the driven wheels at both ends of a rod-shaped member, and at least one of the driven wheels comes into contact with the ground depending on the degree of unevenness of a road surface on which the robot is traveling.

3. 3. The floor cleaning robot according to claim 1, wherein the rotation limiting mechanism includes an elastic member that connects a driving wheel side pin provided on the driving wheel frame and a driven wheel side pin provided on the driven wheel frame while allowing them to be displaced relative to each other.

4. The floor cleaning robot according to any one of claims 1 to 3, wherein the driven wheel is rotatable with respect to a horizontal plane.

5. 2. The floor cleaning robot according to claim 1, wherein the pad portion for cleaning the floor surface is a circular member having a rotation axis at the center of a bottom surface of the drive wheel frame and rotating within a plane along the bottom surface.

Images