Transport Robot

Abstract

A transfer robot is disclosed, comprising: a vehicle body having a wheel drive module installed at the bottom to enable self-movement; a lifting module coupled to the vehicle body so as to be slidably movable and including at least one pair of beam members for lifting and lowering cargo; and a strain gauge installed on the beam members to measure the displacement of the beam members, and estimating the center of gravity that changes as cargo is loaded on the beam members based on the displacement value of the beam members measured by the strain gauge, and correcting control parameters based on the estimated center of gravity.

Description

Technology Field

[0001] The present invention relates to a transport robot for transporting cargo, and more specifically, to a transport robot that improves motion control performance by using a strain gauge to sense the displacement of a beam member loaded with cargo, estimating the changed center of gravity based on the sensed value, and correcting control parameters based on the estimated center of gravity. Background Technology

[0002] Forklifts are vehicles that load relatively heavy cargo, transport it to a location desired by the user, and then unload it; they are widely used across various industries. Generally, forklifts are equipped with hydraulically adjustable fork bars, and they operate by lifting the cargo using the fork bars, moving it, and then lowering it back down at the desired location.

[0003] Conventional forklifts required a driver to operate or drive them, but with the recent increase in demand for logistics mechanization and automation technology, unmanned forklifts are being developed, and interest in such unmanned cargo transport technology is on the rise.

[0004] Furthermore, automatic parking technologies designed to perform autonomous parking without user intervention have recently been introduced, contributing to driver convenience; similarly, automatic parking robots that automatically park vehicles can be viewed as a type of unmanned cargo transportation technology.

[0005] In the case of a parking robot that enters the underside of a vehicle, directly lifts the vehicle, and moves to perform parking, it may be equipped with a fork bar to lift the vehicle similarly to a forklift. A parking robot of this type is configured to move toward the vehicle, lift the vehicle using the fork bar, and move while the vehicle is lifted.

[0006] Utilizing such parking robots not only significantly improves convenience for vehicle users but also enables more efficient use of parking spaces even in confined areas, thereby contributing to alleviating parking shortages and urban traffic congestion.

[0007] Meanwhile, cargo transport devices such as forklifts have appropriate load capacities depending on their size and purpose. However, if the load capacity is exceeded during operation, or if the center of gravity of the fork bar loaded with cargo becomes severely unbalanced due to inexperienced driving or uneven weight distribution of the cargo, there is a risk of personal injury or property damage caused by falling cargo, or safety accidents caused by the device tipping over or overturning. The problem to be solved

[0008] In order to prevent the occurrence of safety accidents as described above, it is necessary to accurately measure the weight and center of gravity of the cargo loaded on the transport device and perform motion control accordingly. To this end, the technical objective of the present invention is to provide a transport robot with significantly improved motion control performance by being configured to automatically correct control parameters according to changes in the center of gravity based on the state of the loaded cargo.

[0009] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0010] According to one aspect of the present invention, a transport robot may be provided, comprising: a vehicle body having a wheel drive module installed at the bottom so as to enable self-movement; a lifting module movably coupled to the vehicle body and including at least one pair of beam members for lifting and lowering cargo; and a strain gauge installed on the beam members to measure the displacement of the beam members, and estimating the center of gravity that changes as cargo is loaded on the beam members based on the displacement value of the beam members measured by the strain gauge, and correcting control parameters based on the estimated center of gravity.

[0011] A transfer robot according to one aspect of the present invention may further include a control unit that receives information regarding the displacement value of the beam member measured by the strain gauge, performs an operation to estimate the changed center of gravity, and automatically corrects control parameters based on the estimated center of gravity.

[0012] The above control unit can perform control to adjust the position of the beam member based on the estimated center of gravity.

[0013] The wheel drive module includes a drive motor for rotating the wheel and a steering motor for adjusting the driving direction of the wheel, and the control unit can perform control to adjust the rotational speed of at least one of the drive motor and the steering motor based on the estimated center of gravity.

[0014] At least one strain gauge may be provided for each of the above beam members.

[0015] A pair of strain gauges is provided for each of the above-mentioned beam members, and the pair of strain gauges can be attached at spaced positions along the longitudinal direction of the beam members.

[0016] The above beam member may be a fork bar capable of being raised or lowered by hydraulics.

[0017] A transfer robot according to one aspect of the present invention may further include a guide rail installed on the vehicle body and supporting the lifting module so as to be slidably movable.

[0018] The beam member includes a vertical portion movably coupled to the guide rail and a horizontal support portion bent from the bottom of the vertical portion and directly supporting the cargo, and the strain gauge may be attached to the upper surface of the horizontal support portion.

[0019] Each of the above beam members can move independently on the guide rail. Effects of the invention

[0020] The transfer robot according to the present invention has the effect of significantly improving motion control performance by using a strain gauge to sense the displacement of a beam member loaded with cargo, estimating the changed center of gravity based on the sensed value, and correcting control parameters based on the estimated center of gravity.

[0021] In addition, the transfer robot according to the present invention has a structure in which the gear part and the motor part of the steering unit provided in the wheel drive module are manufactured separately and detachably coupled to each other, thereby providing excellent assembly and the effect of facilitating maintenance such as parts replacement and repair.

[0022] Furthermore, when the transfer robot according to the present invention is used as a parking robot, automatic parking of a vehicle is possible without user intervention, thereby significantly improving the convenience of the vehicle user and enabling increased space utilization by efficiently making use of limited parking space.

[0023] The effects of the present invention are not limited to those described above, and other unmentioned effects will be clearly understood from the description below. Brief explanation of the drawing

[0024] FIG. 1 is a drawing showing a transfer robot according to the present embodiment. FIG. 2 is a plan view of a transfer robot according to the present embodiment, showing the center of gravity in an unloaded state. FIG. 3 is a plan view of a transfer robot according to the present embodiment, showing the change in the center of gravity in a loaded state with cargo. Figure 4 is an enlarged view of the part marked 'A' in Figure 1, and is a drawing to explain the location where a strain gauge is attached on the beam member. FIG. 5 is a perspective view showing the assembled state of the wheel drive module of the transfer robot according to the present embodiment. FIG. 6 is a side view showing the assembled state of the wheel drive module of the transfer robot according to the present embodiment. FIG. 7 is a perspective view showing the motor part of the steering unit in the wheel drive module of the transfer robot according to the present embodiment. FIG. 8 is a perspective view showing the state in which the gear part and the motor part of the steering unit are separated in the wheel drive module of the transfer robot according to the present embodiment. Specific details for implementing the invention

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The following embodiments are presented to sufficiently convey the concept of the present invention to those skilled in the art to which the present invention pertains. The present invention is not limited to the embodiments presented below and may be embodied in other forms. In the drawings, parts unrelated to the description may be omitted to aid in understanding the present invention, and the size of components may be expressed somewhat exaggeratedly.

[0026] FIG. 1 is a drawing showing a transfer robot according to the present embodiment. FIG. 2 is a plan view of the transfer robot according to the present embodiment, showing the center of gravity in an unloaded state. FIG. 3 is a plan view of the transfer robot according to the present embodiment, showing the change in the center of gravity in a loaded state with cargo. FIG. 4 is an enlarged view of the part marked 'A' in FIG. 1, and is a drawing for explaining the location where a strain gauge is attached on a beam member.

[0027] Also, FIGS. 5 and 6 are a perspective view and a side view, respectively, showing the assembled state of the wheel drive module of the transfer robot according to the present embodiment. FIG. 7 is a perspective view showing the motor part of the steering unit in the wheel drive module of the transfer robot according to the present embodiment, and FIG. 8 is a perspective view showing the state in which the gear part and the motor part of the steering unit are separated in the wheel drive module of the transfer robot according to the present embodiment.

[0028] In the following, a preferred embodiment is described in which the transfer robot according to the present invention is provided as a 'parking robot'. However, the present invention is not limited to or restricted thereto, and the technical concept of the present invention may be applied without regard to form or structure as long as it is a cargo transport device comprising a configuration for lifting cargo (corresponding to 'vehicle' in the hereinafter embodiments) (corresponding to a 'lifting module' in the hereinafter embodiments) and a configuration provided to enable the transfer robot to move independently (corresponding to a 'wheel driving module' in the hereinafter embodiments).

[0029] First, referring to FIG. 1, the transfer robot (10) according to the present embodiment may be configured to include a frame module (100), a lifting module (200) movably installed on the frame module (100), and a wheel driving module (300) installed at the bottom of the frame module (100).

[0030] The transfer robot (10) according to the present embodiment has a frame module (100) as the base of the structure and can be moved in the forward / backward and left / right directions by a wheel drive module (300). In addition, the transfer robot (10) according to the present embodiment can lift a vehicle using a lifting module (200), which is achieved by the lifting unit (210) of the lifting module (200) supporting the wheels of the vehicle from below, as described below. At this time, the transfer robot (10) according to the present embodiment is configured to support both the front and rear wheels of the vehicle so as to be able to stably support the vehicle.

[0031] The transfer robot (10) according to the present embodiment can recognize a vehicle, lift the recognized vehicle, and move it to a designated parking position to perform a parking operation. In addition, the transfer robot (10) according to the present embodiment can be operated automatically. For example, the transfer robot (10) according to the present embodiment can be operated by a remote control device, such as a remote control, without manual operation by a worker or the like.

[0032] In this embodiment, the frame module (100) includes a first frame (110) and a second frame (120) extending from both ends of the first frame (110) in a direction orthogonal to the extension direction of the first frame (110), and has a structure approximately in the shape of a 'C', and can be configured to move on its own by means of a wheel drive module (300) described later.

[0033] The transfer robot (10) according to the present embodiment can approach the side of the vehicle to perform parking of the vehicle. When positioned by approaching the side of the vehicle, the first frame (110) is extended along the front-rear direction of the vehicle, and the second frame (120) is extended along the width direction of the vehicle. Additionally, when the lifting unit (210) of the lifting module (200) described later enters the lower part of the vehicle from the side of the vehicle, the vehicle to be parked is positioned within the 'U'-shaped space formed by the first frame (110) and the second frame (120).

[0034] The frame module (100) can movably support the lifting module (200) described later. The lifting module (200) can slide along the extension direction of the first frame (110) while coupled to the first frame (110) of the frame module (100). To this end, a guide rail may be provided on the first frame (110). The guide rail is installed along the extension direction of the first frame (110) and movably supports the lifting module (200).

[0035] The guide rail is located on the outer side of the first frame (110). The guide rail may be installed to protrude from the outer surface of the first frame (110). Preferably, the guide rail is provided on at least one of the upper surface and the front surface of the first frame (110) to movably support the lifting module (200).

[0036] Inside the first frame (110), a power unit (not shown) for driving the lifting module (200) described later, a power source (not shown) for supplying power to the power unit, and a controller (not shown) for controlling the power unit may be accommodated.

[0037] In this embodiment, the lifting module (200) substantially performs the function of supporting the wheels of the vehicle to lift the vehicle. In order to perform the operation of supporting the wheels of the vehicle to lift, the lifting module (200) can be moved along a guide rail provided on the first frame (110) described above. That is, the lifting module (200) can be movably coupled to a guide rail provided on the first frame (110).

[0038] As described, the lifting module (200) of the present embodiment may be composed of a pair of lifting units (210) to support and lift the front and rear wheels of the vehicle, respectively. Additionally, each lifting unit (210) may be configured to include a pair of beam members (211, 211'), and accordingly, the transfer robot (10) according to the present embodiment may be configured to include a total of four beam members (211, 211').

[0039] The lifting unit (210) can be movably coupled to the guide rail of the first frame (110) described above. Substantially, the beam members (211, 211') constituting the lifting unit (210) can move along the guide rail and come into direct contact with the wheels of the vehicle, thereby supporting and lifting the wheels of the vehicle.

[0040] A lifting unit (210) composed of a total of two pairs of beam members (211, 211') can be moved into the lower part of the vehicle from the left or right side of the vehicle by the movement of a transport robot (10). The horizontal length of the beam members (211, 211') can be determined according to the width of the vehicle.

[0041] The beam member (211, 211') of the present embodiment may be provided as a bent member commonly known as a fork bar. Specifically, the beam member (211, 211') may be composed of a vertical portion (211a) coupled to a guide rail of the first frame (110) and a horizontal support portion (211b) that is bent from the bottom of the vertical portion (211a) and extended horizontally to support the wheel of the vehicle in direct contact. A roller (212) may be installed on the horizontal support portion (211b) at the part that comes into contact with the wheel of the vehicle for the purpose of reducing friction with the wheel.

[0042] A roller (212) may be installed on the surfaces facing each other of a pair of beam members (211, 211') constituting a lifting unit (210), and may be rotatably coupled to the beam members (211, 211'). Additionally, a pair of rollers (212) may be provided to correspond to the positions of the left and right wheels of the vehicle, respectively, and may be installed at positions spaced apart from each other along the longitudinal direction of the beam members (211, 211').

[0043] In addition, in this embodiment, a plurality of beam members (211, 211') constituting the lifting unit (210) can each move independently on the guide rail. For example, a pair of beam members (211, 211') constituting one lifting unit (210) can be moved to approach the wheel side of the vehicle or away from the wheel along the extension direction of the first frame (110) (which is also the extension direction of the guide rail).

[0044] More specifically, when the lifting unit (210) enters the lower part of the vehicle to raise the vehicle's wheels, a pair of beam members (211, 211') are positioned in the front-rear direction relative to the wheels located on the same line along the width direction of the vehicle. At this time, the first beam member (211) located in front of the wheel and the second beam member (211') located behind the wheel can be moved in opposite directions on the guide rail. The first beam member (211) and the second beam member (211') can move closer to each other, that is, in the direction toward the wheel, to support and raise the vehicle's wheels in cooperation, and conversely, the first beam member (211) and the second beam member (211') can move further apart from each other, that is, in the opposite direction toward the wheel, to release the state of supporting the wheel and lower the vehicle.

[0045] The lifting module (200) of the present embodiment may further include a power unit (not shown) for moving the lifting unit (210). The power unit (not shown) may be configured to include a motor, a gear rotated by the motor, a rack to which the gear meshes, etc., so as to be able to move the lifting unit (210) on a guide rail provided in the frame module (100).

[0046] Meanwhile, in this embodiment, the lifting unit (210) is configured to be movable not only in the horizontal direction but also in the vertical direction on the first frame (110), so that it can be positioned to be adjusted when entering the underside of the vehicle or when the vehicle is lifted.

[0047] The wheel drive module (300) substantially performs the function of moving the transfer robot (10) according to the present embodiment. The wheel drive module (300) provides the power to move the transfer robot (10) and also provides a steering function to adjust the direction during the movement process.

[0048] The wheel drive module (300) is installed at the bottom of the frame module (100) to support the frame module (100) so that it can move. The wheel drive module (300) may be provided in multiple numbers, for example, by being installed at each end along the longitudinal direction of the second frame (120), which is a component of the frame module (100), so that four wheel drive modules (300) may be provided per transfer robot (10). That is, the transfer robot (10) according to the present embodiment may be supported at four points by four wheel drive modules (300). However, the present embodiment is not limited thereto, and it is obvious that the number of wheel drive modules (300) provided in one transfer robot (10) may be increased as needed.

[0049] Meanwhile, referring to FIG. 2, the transfer robot (10) according to the present embodiment maintains a constant center of gravity (CoG) without change in a 'no-load state' where nothing is loaded.

[0050] However, as illustrated in FIG. 3, in a 'loaded state' where a load such as a vehicle is loaded onto the transport robot (10), the overall center of gravity changes due to the load. In particular, in the case of a transport robot (10) according to the present embodiment that has a payload higher than the vehicle body, the center of gravity in the loaded state may change significantly depending on the load, and consequently, there is a risk that the motion control performance may rapidly deteriorate. The deterioration of motion control performance may be a factor causing the aforementioned safety accident.

[0051] As a configuration to solve these problems, the transfer robot (10) according to the present embodiment may further include a strain gauge (400) installed on the beam member (211, 211') to measure the displacement of the beam member (211, 211') caused by the loaded cargo.

[0052] Referring to FIGS. 1 and 4, a strain gauge (400) can be attached to the upper surface of a beam member (211, 211'), more specifically, to the upper surface of a horizontal support member (211b) that substantially supports a cargo on the beam member (211, 211').

[0053] In addition, in this embodiment, at least one strain gauge (400) may be provided for each of the plurality of beam members (211, 211'). If strain gauges (400) are installed on both sides along the longitudinal direction of each beam member (211, 211'), a more accurate estimation of the center of gravity will be possible.

[0054] The displacement value sensed by the strain gauge (400) can be transmitted to a control unit (not shown) that controls the operation of the transfer robot (10) according to the present embodiment. The control unit (not shown) can estimate the changed center of gravity of the transfer robot (10) based on the sensed value of the strain gauge (400), and can automatically correct the control parameters based on the estimated center of gravity.

[0055] A transport robot (10) comprising four independent wheel drive modules (300) has basic parameters for control. At this time, if the mass and center of gravity of the cargo loaded on the transport robot (10) change, the load applied to each wheel drive module (300) also changes. Accordingly, the control unit (not shown) of the present embodiment can perform control by adjusting the position or height of each beam member (211, 211') based on the estimated center of gravity, or by adjusting the rotational speed of the drive motor (330) or steering motor (342a) provided in the wheel drive module (300) described later. Through this, the movement angle or driving posture of the transport robot (10) can be stably controlled, and as a result, the control stability of the transport robot (10) can be increased.

[0056] As described above, the present embodiment is configured to automatically correct control parameters based on the center of gravity that changes according to the state (position or shape) of the load loaded on the beam member (211, 211') of the transfer robot (10).

[0057] The structure of the wheel drive module (300) provided in the transfer robot (10) according to the present embodiment will be described in more detail below.

[0058] Referring to FIGS. 5 to 8, the wheel drive module (300) of the present embodiment may be configured to include a wheel (310) which is a wheel, a wheel frame (320) on which the wheel (310) is rotatably mounted, a drive unit (330) for rotating the wheel (310), and a steering unit (340) for rotating the wheel frame (320) to adjust the direction of the wheel (310).

[0059] The drive unit (330) may be provided as a drive motor (330) that is directly coupled to the wheel axle of the wheel (310). The drive motor (330) is mounted on a wheel frame (320) in the opposite direction to where the wheel (310) is mounted, and the drive motor (330) may be connected to the wheel axle of the wheel (310) through a through hole formed in the wheel frame (320).

[0060] The wheel (310) is configured to rotate around a horizontal axis by the force applied by the drive motor (330). The wheel (310) can be rotated clockwise or counterclockwise with the horizontal axis, thereby enabling movement such as forward or backward movement of the transfer robot (10).

[0061] Meanwhile, in the wheel drive module (300) of the transfer robot (10) according to the present embodiment, the steering unit (340) may be manufactured in a structure in which the gear part (341) and the motor part (342) are separated, and the gear part (341) and the motor part (342) may be detachably connected through bolt connection, etc.

[0062] Specifically, the steering unit (340) of the present embodiment may include: a gear section (341) comprising a steering gear (341a) connected to a wheel frame (320) and a gear-side housing (341b) in which the steering gear (341a) is received; and a motor section (342) comprising a steering motor (342a) that applies power to rotate the steering gear (341a), an output gear (342b) that is coupled to the output shaft of the steering motor (342a) and gear-coupled with the steering gear (341a), and a motor-side housing (342c) in which a space is formed to receive the output gear (342b) and the steering motor (342a) is mounted at the bottom.

[0063] First, looking at the configuration of the gear section (341) of the steering unit (340), the steering gear (341a) is provided as a disc gear and can be coupled with a rotation axis provided in the wheel frame (320). Therefore, when the steering gear (341a) rotates, the wheel frame (320) can rotate together with it. The steering gear (341a) is gear-coupled with the output gear (342) of the motor section (342).

[0064] The gear-side housing (341b) provides a space for accommodating the steering gear (341a). The gear-side housing (341b) has a roughly cylindrical structure corresponding to the shape of the steering gear (341a), and a coupling portion is provided on one side for coupling with the motor-side housing (342c) described later.

[0065] More specifically, the gear-side housing (341b) may be provided in a form where one side of the housing, which is provided in a cylindrical shape, is cut open so that the side wall is open. In addition, a plurality of first fastening holes (H1) for bolt connection with the motor-side housing (342c) may be formed in the cut side of the gear-side housing (341b).

[0066] As one side of the gear side housing (341b) is provided in a cut-out shape, when the steering gear (341a) is mounted inside the gear side housing (341b), a part of the steering gear (341a) protrudes to the outside of the gear side housing (341b).

[0067] Next, looking at the configuration of the motor section (342) of the steering unit (340), the steering motor (342a) provides power to rotate the steering gear (341a). The output gear (342b) is coupled to the output shaft of the steering motor (342a), and the outer circumference of the output gear (342b) and the steering gear (341) can be rotated by meshing (gear coupling) with each other.

[0068] The motor-side housing (342c) provides a space for accommodating the output gear (342b). Additionally, a coupling portion for coupling with the aforementioned gear-side housing (341b) may also be provided on one side of the motor-side housing (342c).

[0069] The motor-side housing (342c) has a coupling portion that corresponds to the shape of the gear-side housing (341b). A plurality of second fastening holes (H2) are formed on one side of the motor-side housing (342c) that is coupled to the gear-side housing (341b) so that a bolt (B) can pass through.

[0070] The gear-side housing (341b) and the motor-side housing (342c) can be joined together using a bolt (B). More specifically, the gear-side housing (341b) and the motor-side housing (342c) can be joined together by a bolt (B) that is inserted through the second fastening hole (H2) while the joint portions are butted together, and then screwed into the first fastening hole (H1).

[0071] That is, in this embodiment, the gear portion (341) and the motor portion (342) of the steering unit (340) can be detachably assembled through a bolt connection between the gear-side housing (341b) and the motor-side housing (342c). By loosening the bolt (B), the gear portion (341) and the motor portion (342) of the steering unit (340) can be easily separated.

[0072] The gear-side housing (341b) and the motor-side housing (342c) are combined with each other and provide a space within which the aforementioned steering gear (341a) and output gear (342b) are accommodated. A portion of the steering gear (341a) protruding from the gear-side housing (341b) is accommodated within the space of the motor-side housing (342c).

[0073] Additionally, the main body of the steering motor (342a) may be mounted on the bottom of the motor-side housing (342c). The output shaft of the steering motor (342a) is installed to pass through the motor-side housing (342c), and the output gear (342b) coupled to the output shaft of the steering motor (342a) is accommodated in the internal space of the motor-side housing (342c).

[0074] Looking at the operation of the steering unit (340), the output gear (342b) installed on the output shaft of the steering motor (342a) is rotated by the driving of the steering motor (342a), and the rotational force of the output gear (342b) is transmitted to the steering gear (341a) to rotate the rotation axis of the wheel frame (320), and as a result, the wheel frame (320) can be rotated in a horizontal direction. That is, as the wheel frame (320) connected to the steering gear (341a), which is rotated by the driving of the steering motor (342a), rotates around a vertical axis, the direction of movement of the transfer robot (10) according to the present embodiment can be adjusted.

[0075] The wheel drive module (300) provided in the transfer robot (10) according to the present embodiment has two rotation mechanisms.

[0076] First, the vertical rotation of the wheel (310) is used to implement the movement function of the transfer robot (10). Here, the vertical rotation of the wheel (310) means rotating around a horizontal axis. The vertical rotation of the wheel (310) can be achieved by driving the drive unit (330), thereby allowing the transfer robot (10) to move forward or backward.

[0077] Cases where the transfer robot (10) according to the present embodiment needs to move include when the transfer robot (10) moves to the location of the vehicle to be parked, when the lifting unit (210) is to be brought under the vehicle to begin parking the vehicle, when the vehicle is moved to a designated parking location while being lifted, when the lifting unit (210) is to be withdrawn from under the vehicle after parking the vehicle is completed, and when the transfer robot (10) leaves the area after parking the vehicle is completed.

[0078] Secondly, horizontal rotation of the wheel frame (320) is implemented to implement a steering function that adjusts the direction of movement when the transfer robot (10) moves. Here, horizontal rotation of the wheel frame (320) means rotating around a vertical axis. Horizontal rotation of the wheel frame (320) can be achieved by driving the steering unit (340), more specifically by the steering unit (340) rotating the wheel frame (320) on which the wheel (310) is mounted, thereby changing the direction of movement of the transfer robot (10).

[0079] That is, in the wheel drive module (300) of the transfer robot (10) according to the present embodiment, the drive unit (330) is provided to provide power necessary for the movement of the transfer robot (10), and the steering unit (340) is provided to provide power for adjusting the direction of movement of the transfer robot (10).

[0080] Below, we will examine the process of parking a vehicle by the transport robot (10) according to the present embodiment, that is, the process of transporting cargo.

[0081] To initiate the parking operation of a vehicle, the transfer robot (10) according to the present embodiment moves to the side of the vehicle to be parked. Additionally, the transfer robot (10) according to the present embodiment can move further toward the vehicle while positioned on the side of the vehicle so that the lifting unit (210) can enter under the vehicle. Such movement of the transfer robot (10) can be achieved by a remote control device controlling the wheel drive module (300), and as described above, the movement of the transfer robot (10) is implemented through the driving of the drive unit (330), and the direction of movement of the transfer robot (10) can be adjusted through the driving of the steering unit (340).

[0082] The lifting unit (210) enters the underside of the vehicle so that a pair of beam members (211, 211') are positioned in front of and behind each wheel located at the front and rear of the vehicle to be parked. When the lifting unit (210) enters the underside of the vehicle, the height of the lifting unit (210) or the width between the pair of beam members (211, 211') constituting the lifting unit (210) may be adjusted as needed. For example, the transfer robot (10) can scan information such as the height and wheel width of the vehicle to be parked and drive a power unit (not shown) provided in the lifting module (200) accordingly to appropriately adjust the vertical and horizontal positions of the beam members (211, 211').

[0083] When the lifting unit (210) enters the lower part of the vehicle, a pair of beam members (211, 211') constituting the lifting unit (210) are positioned facing each other with the wheels in between. In this state, the lifting module (200) can be driven to control the pair of beam members (211, 211') to move in a direction facing each other. As a result, the pair of beam members (211, 211') come into contact with the wheels. If the pair of beam members (211, 211') are moved further toward each other, the wheels of the vehicle can be lifted while supported by the pair of beam members (211, 211') and separated from the ground.

[0084] Meanwhile, when the vehicle is lifted using the lifting unit (210), the overall center of gravity of the transport robot (10) may change due to the weight of the loaded vehicle. In response to this, the present embodiment can be configured to automatically correct control parameters by using a strain gauge (400) attached to the beam member (211, 211') to sense the displacement of the beam member (211, 211'), and a control unit (not shown) to estimate the changed center of gravity of the transport robot (10) based on the sensing value received from the strain gauge (400).

[0085] The transport robot (10), which lifts the vehicle using the lifting unit (210), can move to a designated parking position by operating the wheel drive module (300), and after moving to the desired parking position, can complete the parking operation by lowering the vehicle to the designated parking position.

[0086] When lowering the vehicle, a pair of beam members (211, 211') are moved away from each other, thereby allowing the vehicle's wheels to descend and come into contact with the ground. Additionally, in this state, the pair of beam members (211, 211') can be moved further to be completely separated from the wheels, after which the transfer robot (10) can complete the parking operation of the vehicle and move to another location.

[0087] As described above, the transfer robot (10) according to the present embodiment can achieve automatic parking of a vehicle by continuously or repeatedly performing the operation of moving the frame module (100) forming the body using the wheel drive module (300) and the operation of lifting or lowering the vehicle using the lifting module (200).

[0088] The transfer robot (10) according to the present embodiment has the effect of significantly improving motion control performance by using a strain gauge (400) attached to a beam member (211, 211') to sense the displacement of the beam member (211, 211') when loading cargo such as a vehicle, estimating the changed center of gravity based on the sensing value of the strain gauge (400), and correcting control parameters based on the estimated center of gravity.

[0089] In addition, the transfer robot (10) according to the present embodiment has a structure in which the gear part (341) and the motor part (342) of the steering unit (340) provided in the wheel drive module (300) are manufactured separately and detachably coupled to each other, thereby having excellent assembly capabilities and the effect of facilitating maintenance such as parts replacement and repair.

[0090] Furthermore, when the transfer robot (10) according to the present embodiment is used as a parking robot, automatic parking of a vehicle is possible without user intervention, thereby greatly improving the convenience of the vehicle user and increasing space utilization by efficiently utilizing the limited parking space. Explanation of the symbols

[0091] 10: Transfer robot 100: Frame Module 110: 1st frame 120: 2nd frame 200: Elevator Module 210: Lifting Unit 211, 211': Beam member 211a: Vertical section 211b: Horizontal support 212: Roller 300: Wheel drive module 310: Wheel 320: Wheel frame 330: Drive unit (drive motor) 340: Steering unit 341: Gear section 341a: Steering gear 341b: Gear side housing 342: Motor section 342a: Steering motor 342b: Output gear 342c: Motor side housing 400: Strain gauge

Claims

Claim 1 A transfer robot comprising: a frame module having a wheel drive module installed at the bottom to enable self-movement; a lifting module movably coupled to the frame module and including at least one pair of beam members for lifting and lowering cargo; and a strain gauge installed on the beam members to measure the displacement of the beam members, wherein the frame module includes a first frame on which the lifting module is installed and a pair of second frames extending from both ends of the first frame in a direction orthogonal to the extension direction of the first frame, and estimating the center of gravity that changes as cargo is loaded on the beam members based on the displacement value of the beam members measured by the strain gauge, and correcting control parameters based on the estimated center of gravity. Claim 2 A transfer robot according to claim 1, further comprising a control unit that receives information regarding the displacement value of the beam member measured by the strain gauge, performs an operation to estimate the changed center of gravity, and automatically corrects control parameters based on the estimated center of gravity. Claim 3 A transfer robot according to paragraph 2, wherein the control unit performs control to adjust the position of the beam member based on the estimated center of gravity. Claim 4 A transfer robot according to paragraph 3, wherein the wheel drive module includes a drive motor for rotating the wheel and a steering motor for adjusting the driving direction of the wheel, and the control unit performs control to adjust the rotational speed of at least one of the drive motor and the steering motor based on the estimated center of gravity. Claim 5 A transfer robot according to claim 1, wherein at least one strain gauge is provided for each of the beam members. Claim 6 A transfer robot according to claim 5, wherein a pair of strain gauges is provided for each of the beam members, and the pair of strain gauges are attached at spaced positions along the longitudinal direction of the beam members. Claim 7 A transfer robot according to claim 1, characterized in that the beam member is a fork bar capable of being raised or lowered by hydraulic pressure. Claim 8 A transfer robot according to claim 1, further comprising a guide rail installed on the frame module and supporting the lifting module so as to be slidably movable. Claim 9 A transfer robot according to claim 8, wherein the beam member comprises a vertical portion movably coupled on the guide rail and a horizontal support portion bent from the lower end of the vertical portion and directly supporting a cargo, and the strain gauge is attached to the upper surface of the horizontal support portion. Claim 10 In claim 9, each of the above beam members moves independently on the guide rail, a transfer robot. Claim 11 A transfer robot according to claim 1, wherein the wheel drive module is installed at each of the two ends along the longitudinal direction of the second frame.

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