Unmanned transfer robot

Abstract

In an embodiment, an unmanned transfer robot for transferring a cart loaded with articles includes: a pair of driving wheels rotationally driven in a differential manner and provided spaced apart from each other to both sides; a steering mechanism for adjusting the angle of a driving direction of the pair of driving wheels, to enable diagonal driving; and at least one rotating caster provided at a position spaced apart from the pair of driving wheels and driven and rotated by rotational driving of the pair of driving wheels.

Description

unmanned transport robot

[0001] The present invention relates to an unmanned transport robot, and more particularly, to an unmanned transport robot capable of accurately and quickly transporting a cart to a set final docking position.

[0002] With the rapid development of the logistics industry, various logistics systems are being developed. For example, unmanned transport robots are being used to increase logistics management efficiency and thus productivity.

[0003] Examples of such unmanned transport robots include automatic guided vehicles (AGVs) and autonomous mobile robots (AMRs).

[0004] The aforementioned automated guided vehicles (AGVs) are robots that move along fixed paths or tracks to transport materials. Their ability to efficiently perform repetitive movement of items makes them used in various industrial settings. The aforementioned autonomous mobile robots (AMRs) receive real-time guidance on their movement paths using various sensors and can adjust their paths in real time, even without fixed paths or tracks.

[0005] For example, a plurality of driving wheels are provided on both sides of the bottom of an unmanned transport robot, and in order to ensure smooth rotation of the unmanned transport robot, the plurality of driving wheels can be driven in a differential drive manner by respective driving motors.

[0006] Fig. 1 is a drawing showing the driving appearance of a conventional unmanned transport robot (10) with a differential drive system when changing the left and right positions. The conventional unmanned transport robot (10) may be structured such that a pair of casters (12, 13, 14, 15) are provided on both sides of the front bottom surface and the rear bottom surface of the robot body (11), respectively, and a pair of driving wheels (16, 17) are provided on both sides of the front-back middle bottom surface of the robot body (10).

[0007] In the case of a conventional unmanned transport robot (10) with a differential drive system, body rotation is essential when changing left and right positions during driving. Therefore, when correcting left and right positions while approaching the final docking position (1), the possibility of a collision (P1) increases due to body rotation. In order to avoid such a collision, the unmanned transport robot (10) must be moved left and right by repeatedly moving forward and backward, which poses the problem of requiring a lot of time to move to the set final docking position (1).

[0008] Figure 2 is a drawing for explaining the difference in docking precision between (a) a case where an unmanned transport robot (20) of a conventional differential driving method transports a cart (30) with a relatively small turning radius (R1), and (b) a case where an unmanned transport robot (20) transports a cart (40) with a relatively large turning radius (R2).

[0009] The above unmanned transport robot (20) may include a pair of casters (22, 23) provided in the left and right middle portions of the front bottom surface of the robot body (21), and a pair of driving wheels (24, 25) provided on both sides of the rear bottom surface of the robot body (21) facing the cart (30, 40).

[0010] The bogie (30) illustrated in Fig. 2 (a) is provided with bogie pillars (32, 33, 34, 35) at each corner of the bogie body (31), and a pair of bogie pillars (32, 33) located on both sides of the front can be gripped by a pair of fingers (26, 27). The turning radius (R1) is the distance from the center (C) between a pair of driving wheels (24, 25) to the farthest diagonal corner (A, B) of the bogie (30).

[0011] The bogie (40) illustrated in Fig. 2 (b) is provided with bogie pillars (42, 43, 44, 45) at each corner of the bogie body (41), and a pair of bogie pillars (42, 43) located on both sides of the front can be gripped by a pair of fingers (26, 27). The turning radius (R2) is the distance from the center (C) between a pair of driving wheels (24, 25) to the farthest diagonal corner (D, E) of the bogie (40).

[0012] As the length of the cart increases, the turning radius increases, and as a result, when the unmanned transport robot docks the cart and the device at the final docking position (1), the cart (40) shown in Fig. 2 (b) moves significantly even at a small turning angle compared to the cart (30) shown in Fig. 2 (a), making it difficult to correct the left and right position.

[0013] Figure 3 shows a problem in which a collision (P2) occurs at the final docking position (1) and docking precision is low even when a conventional differential driving unmanned transport robot (20) transports a cart (30) with a relatively small turning radius.

[0014] The prior art related to a differential driving type transport robot is disclosed in Korean Patent No. 10-0322316.

[0015] The present invention has been devised to solve the above-described problems, and its purpose is to provide an unmanned transport robot capable of accurately and quickly transporting a cart to a set final docking position.

[0016] In order to achieve the above-described purpose, the present invention provides an unmanned transport robot that transports a cart on which goods are loaded, the unmanned transport robot comprising: a pair of driving wheels that are differentially rotated and spaced apart from each other on both sides; a steering mechanism that adjusts a driving direction angle of the pair of driving wheels to enable diagonal driving; and at least one rotary caster that is provided at a position spaced apart from the pair of driving wheels and is rotated by rotational driving of the pair of driving wheels.

[0017] The above pair of driving wheels may include a first driving wheel driven by a first driving wheel driving motor, and a second driving wheel driven by a second driving wheel driving motor, wherein the first driving wheel and the first driving wheel driving motor rotate about a first rotation axis to enable adjustment of a driving direction angle, and the second driving wheel and the second driving wheel driving motor rotate about a second rotation axis to enable adjustment of a driving direction angle, and the steering mechanism may include an actuator, a rod that reciprocates left and right by driving the actuator, and a plurality of links that connect and interlock the rod, the first rotation axis, and the second rotation axis.

[0018] The plurality of links may include a first link having one end rotatably connected to an end of the rod by a first hinge portion and the other end coupled to the first rotational axis and having a length in the front-back direction; a second link having one end rotatably connected to a middle portion of the first link by a second hinge portion and having a length in the left-right direction; and a third link having one end rotatably connected to the other end of the second link by a third hinge portion and the other end coupled to the second rotational axis and having a length in the front-back direction.

[0019] The above pair of driving wheels may be provided on both sides of the rear bottom surface of the robot body facing the cart, and the at least one rotary caster may be provided as a pair on the left and right middle portions of the front bottom surface of the robot body.

[0020] The above pair of driving wheels may be provided on both sides of the front-rear middle bottom surface of the robot body, and the at least one rotary caster may be provided as a pair on both sides of the front bottom surface of the robot body and on both sides of the rear bottom surface of the robot body, respectively.

[0021] It may include a pair of fingers for gripping a pair of bogie columns provided in an upright state on one side of the bogie, and a pair of grippers for moving the pair of fingers to grip or release the pair of bogie columns.

[0022] According to the unmanned transport robot according to the present invention, by providing a steering mechanism capable of adjusting the driving angle of the differential driving wheel, the docking precision of the bogie is improved, so that the bogie can be accurately and quickly transported to the set final docking position.

[0023] In addition, since the fingers driven by the gripper are configured to grab and pull the bogie column, application is possible without changing the structure of the bogie, and the bogie can be stably transported in a towing manner.

[0024] In addition, the operation of the gripper can be precisely controlled by having a pair of grip detection sensors to detect whether the fingers are gripping or releasing the bogie column.

[0025] In addition, a collision detection sensor is installed on the finger or gripper and is configured to detect whether there is an object that may collide with the cart on either side of the cart being towed, and by controlling the driving of the unmanned transport robot, the cart and the load loaded on it can be prevented from colliding with the object and being damaged in advance.

[0026] Figure 1 is a drawing showing the driving appearance of an unmanned transport robot with a conventional differential driving method when changing the left and right positions.

[0027] Figure 2 is a drawing for explaining the difference in docking precision between (a) a case where a conventional differential driving unmanned transport robot transports a cart with a relatively small turning radius, and (b) a case where an unmanned transport robot transports a cart with a relatively large turning radius.

[0028] Figure 3 is a drawing to explain the problem of low docking precision even when a conventional differential driving unmanned transport robot transports a cart within a turning radius.

[0029] FIG. 4 is a drawing showing a driving state of an unmanned transport robot according to one embodiment of the present invention with improved docking precision through diagonal driving.

[0030] FIG. 5 is a perspective view showing the first and second fingers of an unmanned transport robot according to one embodiment of the present invention gripping a cart pillar.

[0031] FIG. 6 is a plan view for explaining the operation of a grip detection sensor and a collision avoidance sensor provided in an unmanned transport robot according to one embodiment of the present invention.

[0032] Figure 7 is a front view of the unmanned transport robot illustrated in Figure 6;

[0033] FIG. 8 is a bottom view of FIG. 6 showing a steering mechanism provided on the bottom surface of an unmanned transport robot according to one embodiment of the present invention;

[0034] Fig. 9 is a bottom view showing the state in which the first finger and the second finger slide to both sides by the driving of the first gripper and the second gripper in the state of Fig. 8, thereby releasing the gripping state of the bogie column, and the driving wheel is rotated to one side by the driving of the steering mechanism.

[0035] FIG. 10 is a drawing showing a driving state of an unmanned transport robot according to another embodiment of the present invention with improved docking precision through diagonal driving.

[0036] Figures 11 and 12 are bottom views showing a steering mechanism provided on the bottom of an unmanned transport robot according to another embodiment of the present invention and its operation.

[0037] ** Explanation of symbols **

[0038] 1: Final docking position 10: Unmanned transport robot

[0039] 11: Robot body 12,13,14,15: Caster

[0040] 16, 17: Driving wheel 20: Unmanned transport robot

[0041] 21: Robot body 22,23: Rotating caster

[0042] 24,25: Driving wheel 26,27: Finger

[0043] 30: Short bogie 31: Bogie body

[0044] 32,33,34,35: Bogie pillar 40: Long bogie

[0045] 40A: Docking surface of bogie 41: Bogie body

[0046] 42,43,44,45: Bogie pillar 100: Unmanned transport robot

[0047] 100A: Docking surface of the robot 110: Robot body

[0048] 111: Lidar sensor 121,122: Rotating caster

[0049] 130: First driving wheel 131: First driving wheel drive motor

[0050] 131a: First rotation axis 140: Second driving wheel

[0051] 141: Second driving wheel drive motor 141a: Second rotation shaft

[0052] 150: 1st finger 151: Straight part

[0053] 152: bend 160: second finger

[0054] 170: 1st gripper 171: 1st drive unit

[0055] 172: First shaft 173: First shaft guide

[0056] 174: First moving member 175: First moving member guide

[0057] 176: First connecting member 177: First finger mounting member

[0058] 178,178a,178b: First grip detection sensor 179: First collision detection sensor

[0059] 180: Second gripper 181: Second drive unit

[0060] 182: Second shaft 183: Second shaft guide

[0061] 184: Second moving member 185: Second moving member guide

[0062] 186: Second connecting member 187: Second finger mounting member

[0063] 188,188a,188b: Second grip detection sensor 189: Second collision detection sensor

[0064] 190: Steering mechanism 191: Actuator

[0065] 192: Rod 193: First hinge

[0066] 194: First link 195: Second hinge

[0067] 196: Second link 197: Third hinge

[0068] 198: Third Link 200: Unmanned Transport Robot

[0069] 210: Robot body 220,230,240,250: Rotating caster

[0070] 260: First driving wheel 261: First driving wheel drive motor

[0071] 261a: First rotation axis 270: Second driving wheel

[0072] 271: Second driving wheel drive motor 271a: Second rotation shaft

[0073] 280: Steering mechanism 281: Actuator

[0074] 282: Rod 283: First hinge

[0075] 284: First link 285: Second hinge

[0076] 286: Second link 287: Third hinge

[0077] 288: Third Link

[0078] The configuration and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0079] Referring to FIGS. 4 and 5, an unmanned transport robot (100) according to one embodiment of the present invention is a device for transporting a cart (30, 40) in a towing manner and docking it so that it is positioned at a final docking location (1). The unmanned transport robot (100) moves the cart (30, 40) forward by pulling it, and moves it backward from the final location to dock the cart (30, 40) to a target point device.

[0080] Fig. 4 (a) illustrates a case where a bogie (30) having a relatively short length in the forward / reverse direction is transported and docked at the final docking position (1), and Fig. 4 (b) illustrates a case where a bogie (40) having a relatively long length in the forward / reverse direction is transported and docked at the final docking position (1).

[0081] The above-mentioned cart (30, 40) is provided with cart pillars (22, 23, 24, 25, 42, 43, 44, 45) which are respectively installed in an upright state at the corners of the cart body (31, 41) on which the load is loaded, and the unmanned transport robot (100) is configured to transport the cart (30, 40) by pulling it while gripping a pair of cart pillars (22, 23, 42, 43) installed on both sides of the front of the cart (30, 40) with a pair of fingers (150, 160).

[0082] Hereinafter, an example will be described in which the unmanned transport robot (100) transports a cart (40) having a relatively long length in the front-rear direction.

[0083] The above unmanned transport robot (100) includes a pair of driving wheels (130, 140) that are rotationally driven in a differential drive manner and spaced apart from each other on both sides, and at least one rotary caster (121, 122) that is driven by the rotation of the pair of driving wheels (130, 140), and the pair of driving wheels (130, 140) are configured to be angle-adjusted in the driving direction by the driving of a steering mechanism (190; FIG. 8) described below so as to enable diagonal driving.

[0084] Here, the differential method means a driving method in which the pair of driving wheels (130, 140) are individually driven for rotation by each driving wheel driving motor (131, 141; FIG. 8), and the rotation speed of the pair of driving wheels (130, 140) located on both sides is differentially controlled in response to the rotation angle during rotational driving, thereby enabling smooth rotational driving.

[0085] At least one rotary caster (121, 122) that is driven and rotates by the rotation of the pair of driving wheels (130, 140) is provided on the bottom surface of the robot body (110) at a position spaced apart from the pair of driving wheels (130, 140). In one embodiment, the rotary casters (121, 122) may be provided as a pair at the center of the front portion of the bottom surface of the robot body (110).

[0086] The above pair of fingers (150, 160) are configured to grip a pair of cart pillars (42, 43) provided in an upright state on both ends of the cart docking surface (40A; FIG. 8) of the cart (40) facing the robot docking surface (100A; FIG. 8), or to release the gripped state.

[0087] Referring to FIG. 5, a lidar sensor (111) may be provided on one upper side of the unmanned transport robot (100) to measure the position coordinates of a reflector by shooting a laser pulse in the direction of travel and measuring the time it takes for the laser pulse to be reflected and returned while transporting the cart (40).

[0088] Referring to FIGS. 5 and 6, in one embodiment, the bogie pillars (42, 43) of the bogie (40) may be formed in a rectangular parallelepiped shape having a length in the vertical direction, and the pair of fingers (150, 160) may be formed by a straight portion (151; FIG. 6) located on the outside of the pair of bogie pillars (42, 43) and having a length in the front-back direction, and a bent portion (152) formed by bending and extending in a direction toward the bogie pillars (42, 43) from the rear end of the straight portion (151), respectively.

[0089] The above pair of fingers (150, 160) is composed of a first finger (150) provided on one side of the rear portion of the robot body (110) and gripping a cart pillar (42) provided on one side of the docking portion of the cart (40), and a second finger (160) provided on the other side of the rear portion of the robot body (110) and gripping a cart pillar (43) provided on the other side of the docking portion of the cart (40).

[0090] In one embodiment, the first finger (150) and the second finger (160) can be driven to move back and forth in the left and right directions by a pair of grippers (170, 180).

[0091] The above pair of grippers (170, 180) can be configured to grip a pair of bogie columns (42, 43) by moving the pair of fingers (150, 160) in a mutually approaching direction as shown in FIGS. 6 and 7, or to release the gripping state of a pair of bogie columns (42, 43) by moving the pair of fingers (150, 160) in a mutually spaced direction as shown in FIG. 8.

[0092] The above pair of grippers (170, 180) is composed of a first gripper (170) that moves the first finger (150) in the left-right direction, and a second gripper (180) that moves the second finger (160) in the left-right direction.

[0093] Referring to FIG. 7, the first gripper (170) may include a first driving unit (171), a first shaft (172) that reciprocates by driving the first driving unit (171), a first shaft guide (173) that guides the reciprocating movement of the first shaft (172), a first moving member (174) that is coupled to the first shaft (172) and reciprocates integrally, a first moving member guide (175) that guides the reciprocating movement of the first moving member (174), a first connecting member (176) that is coupled to the first moving member (174), and a first finger mounting member (177) that is coupled to the first connecting member (176) and has a first finger (150) mounted thereon.

[0094] The above second gripper (180) is located below the first gripper (170) and is provided with a structure that is symmetrical left and right with respect to the first gripper (170).

[0095] The second gripper (180) may include a second driving unit (181), a second shaft (182) that reciprocates by driving the second driving unit (181), a second shaft guide (183) that guides the reciprocating movement of the second shaft (182), a second moving member (184) that is coupled to the second shaft (122) and reciprocates integrally, a second moving member guide (185) that guides the reciprocating movement of the second moving member (184), a second connecting member (186) that is coupled to the second moving member (184), and a second finger mounting member (187) that is coupled to the second connecting member (186) and has a second finger (150) mounted thereon.

[0096] Referring to Fig. 8, the casters provided on the bottom of the cart (40) and the unmanned transport robot (100) are not fixed casters but rather rotating casters (46, 47, 48, 49, 121, 122).

[0097] Taking the rotary caster (46) provided on the above-mentioned carriage (40) as an example, the center line (L1) along which the wheel rotates in the driving direction and the center line (L2) of the bearing (46a) that rotates left and right are eccentric in the front-back direction, and the rotary caster (121, 122) provided on the above-mentioned unmanned transport robot (100) also has the center line (L3) along which the wheel rotates in the driving direction and the center line (L4) of the bearing (121a, 122a) that rotates left and right are eccentric in the front-back direction.

[0098] By applying the rotary casters (46, 47, 48, 49, 121, 122) to the cart (20) and the unmanned transport robot (100) in this way, smooth rotational driving is possible when changing direction when the unmanned transport robot (100) transports the cart (40) by towing.

[0099] Meanwhile, referring to FIG. 6, the robot body (110) includes a pair of fingers (150, 160) and a pair of grip detection sensors (178, 188) for detecting a state in which a pair of cart pillars (22, 23) are gripped or released.

[0100] The above pair of grip detection sensors (178, 188) may be composed of a plurality of grip detection sensors (178a, 178b, 188a, 188b) positioned spaced apart from each other on both sides. When the plurality of grip detection sensors (178a, 178b, 188a, 188b) output a signal indicating that they have detected both of a pair of bogie columns (22, 23), it is determined that the pair of fingers (150, 160) are gripping the pair of bogie columns (22, 23), and when the plurality of grip detection sensors (178a, 178b, 188a, 188b) output a signal indicating that they have not detected both of a pair of bogie columns (22, 23), it is determined that the gripping of the pair of fingers (150, 160) on the pair of bogie columns (22, 23) is released, and the driving of the pair of grippers (170, 180) can be controlled.

[0101] It includes a pair of collision detection sensors (179, 189) mounted on the pair of fingers (150, 160) or grippers (170, 180) and configured to detect whether there is an object capable of colliding with the cart (20) on both sides of the cart (20) being towed.

[0102] When at least one of the pair of collision detection sensors (179, 189) outputs a signal detecting the presence of the counterpart, the operation of the pair of driving wheels (130, 140) is controlled to stop, thereby preventing the bogie (20) and the load loaded thereon from colliding with the counterpart and being damaged in advance.

[0103] Referring to FIGS. 8 and 9, the pair of driving wheels (130, 140) includes a first driving wheel (130) driven by a first driving wheel driving motor (131) and a second driving wheel (140) driven by a second driving wheel driving motor (141). The first driving wheel (130) and the first driving wheel driving motor (131) can be rotated about a first rotation axis (131a) to adjust the driving direction angle, and the second driving wheel (140) and the second driving wheel driving motor (141) can be rotated about a second rotation axis (140a) to adjust the driving direction angle.

[0104] The above steering mechanism (190) may include an actuator (191), a rod (192) that moves back and forth in the left and right direction by driving the actuator (191), and a plurality of links (194, 196, 198) that connect and interlock the rod (192) with the first rotation shaft (131a) and the second rotation shaft (140a).

[0105] The above plurality of links (194, 196, 198) may include a first link (194) having one end rotatably connected to an end of the load (192) by a first hinge portion (193) and the other end coupled to the first rotation shaft (131a) and having a length in the front-back direction, a second link (196) having one end rotatably connected to a middle portion of the first link (194) by a second hinge portion (195) and having a length in the left-right direction, and a third link (198) having one end rotatably connected to the other end of the second link (196) by a third hinge portion (197) and the other end coupled to the second rotation shaft (141a) and having a length in the front-back direction.

[0106] FIG. 8 illustrates a case where the first driving wheel (130) and the second driving wheel (140) of the unmanned transport robot (100) are positioned parallel to the front-back direction so that the unmanned transport robot (100) tows and transports the cart (40) in a straight direction, and FIG. 9 illustrates a case where the first driving wheel (130) and the second driving wheel (140) of the unmanned transport robot (100) are rotated to one side by the driving of the steering mechanism (190) so that the unmanned transport robot (100) tows and transports the cart (40) in a diagonal direction.

[0107] In this way, in the present invention, by providing a steering mechanism (190) capable of adjusting the driving angle to the differential driving wheel (130, 140), even when the length of the bogie (40) is relatively long, as shown in Fig. 4 (b), docking precision is improved, so that the bogie (40) can be accurately and quickly positioned to the final docking position (1) set without collision.

[0108] That is, by providing the steering mechanism (190), the rotation of the body is unnecessary when correcting the left and right position in a state close to the final docking position (1), so that a collision caused by this can be prevented, and since diagonal driving is possible without the need to move the position left and right by repeating forward and backward movements, the time for transporting the unmanned transport robot (100) to the set final docking position (1) can be significantly shortened.

[0109] In this embodiment, the pair of driving wheels (130, 140) are provided on both sides of the rear bottom surface of the robot body (110) facing the cart (40), and the at least one rotary caster (121, 122) is provided as a pair on the left and right middle portions of the front bottom surface of the robot body (110).

[0110] In this way, by positioning the pair of driving wheels (130, 140) on both sides of the robot docking surface (100A; FIG. 8), the turning radius of the cart (40) can be reduced when the cart (40) rotates, thereby improving the docking precision of the cart (40). That is, by positioning the pair of driving wheels (130, 140) as close as possible to the cart (40), the turning radius of the rear end of the cart (40) is reduced when the unmanned transport robot (100) rotates according to the differential drive of the pair of driving wheels (130, 140), thereby enabling the cart (40) to be docked with high precision in a state close to the final docking position.

[0111] Referring to FIGS. 10 to 12, an unmanned transport robot (200) according to another embodiment may be provided with a pair of driving wheels (260, 270) on both sides of the front-rear middle bottom surface of the robot body (210), and at least one rotary caster (220, 230, 240, 250) may be provided as a pair on both sides of the front bottom surface of the robot body (210) and on both sides of the rear bottom surface of the robot body (210).

[0112] As in the above-described embodiment, the steering mechanism (280) for adjusting the driving direction angle of the pair of driving wheels (260, 270) comprises: an actuator (281), a rod (282) that reciprocates left and right by driving the actuator (281), a first link (284) having a first end rotatably connected to an end of the rod (282) by a first hinge part (283) and the other end coupled to a first rotation axis (261a) that serves as a center of rotation for adjusting the driving direction angle of the first driving wheel (260) and the first driving wheel driving motor (261) and having a length in the front-back direction, a second link (286) having a second end rotatably connected to a middle portion of the first link (284) by a second hinge part (285) and having a length in the left-right direction, and a third hinge part (287) connected to the other end of the second link (286). One end is rotatably connected by a third link (288) and the other end is connected to a second rotation shaft (271a) that serves as a center of rotation for adjusting the driving direction angle of the second driving wheel (270) and the second driving wheel driving motor (271), and has a length in the front-back direction.

[0113] Although the present invention has been described in detail with reference to preferred embodiments as described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the attached drawings, and these also belong to the present invention.

Claims

1. An unmanned transport robot that transports a cart loaded with goods by towing. A pair of drive wheels, which are rotated differentially and spaced apart on both sides; A steering mechanism that enables diagonal driving by adjusting the driving direction angle of the above pair of driving wheels; and At least one rotary caster provided at a position spaced apart from the pair of driving wheels and rotated by the rotational drive of the pair of driving wheels; An unmanned transport robot including:

2. In paragraph 1, The above pair of driving wheels comprises a first driving wheel driven by a first driving wheel driving motor and a second driving wheel driven by a second driving wheel driving motor. The above first driving wheel and the first driving wheel drive motor rotate around the first rotation axis so that the driving direction angle can be adjusted. The above second driving wheel and the second driving wheel drive motor rotate around the second rotation axis so that the driving direction angle can be adjusted. The steering mechanism is an unmanned transport robot including an actuator, a rod that moves back and forth in the left and right direction by driving the actuator, and a plurality of links that connect and interlock the rod, the first rotation axis, and the second rotation axis.

3. In paragraph 2, The above multiple links are, A first link having one end rotatably connected to the end of the above load by a first hinge portion and the other end coupled to the first rotation axis and having a length in the front-back direction; A second link having a second hinge portion rotatably connected to the middle portion of the first link and having a length in the left-right direction; and A third link having one end rotatably connected to the other end of the second link by a third hinge portion and the other end coupled to the second rotation axis and having a length in the front-back direction; An unmanned transport robot including:

4. In paragraph 1, The above pair of driving wheels are provided on both sides of the rear bottom surface of the robot body facing the cart, An unmanned transport robot characterized in that at least one of the above-mentioned rotary casters is provided in pairs at the left and right middle portions of the front bottom surface of the robot body.

5. In paragraph 1, The above pair of driving wheels are provided on both sides of the middle bottom surface in the front-rear direction of the robot body, An unmanned transport robot characterized in that the at least one rotary caster is provided as a pair on both sides of the front bottom surface of the robot body and on both sides of the rear bottom surface of the robot body.

6. In paragraph 1, A pair of fingers for gripping a pair of bogie columns provided in an upright position on one side of the bogie; A pair of grippers that move the pair of fingers to grip or release the gripping state of the pair of bogie columns; An unmanned transport robot including:

Images