Mobile robot

Abstract

A mobile robot is provided with: a trolley unit; a movement mechanism that causes the carriage unit to turn; an arm portion including: a first joint connected to the carriage portion and having a first rotation axis in a vertical direction; a trolley-side arm adjustment part including a joint having a first end and a second end, the first end being connected to the first joint, the joint having an orthogonal rotation axis orthogonal to the first rotation axis; an intermediate arm adjustment portion having a third end portion and a fourth end portion, the third end portion being connected to the second end portion; and a tip-side arm region connected to the fourth end portion; and a control unit for controlling the movement mechanism and the arm unit, the control unit controlling the first joint such that the orthogonal axis of rotation is perpendicular to the traveling direction of the trolley unit when the trolley unit is turning, and controlling the intermediate joint included in the intermediate arm adjustment unit. The center-of-gravity position of the tip-side arm region is moved in the direction toward the turning center than the center-of-gravity position before turning.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a mobile robot. BACKGROUND

[0002] A trolley moving robot having a trolley and a manipulator mounted on the trolley is described in WO 2021 / 235520. The manipulator has a turning body rotatably supported by a base and a plurality of arms supported by the turning body. SUMMARY

[0003] PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] In order to handle an object for operation and convey the object, a mobile robot having a trolley section and an arm section mounted on the trolley section can be used. One of suitable basic structures of the arm section is a structure having a first joint connected to the trolley section and having a first rotation axis in the vertical direction, a trolley-side arm adjustment section having a lower end connected to the first joint, and an upper limb section from an upper end of the trolley-side arm adjustment section to an end effector. The trolley-side arm adjustment section has one joint having one orthogonal rotation axis orthogonal to the first rotation axis or a plurality of joints each having a plurality of orthogonal rotation axes orthogonal to the first rotation axis and parallel to each other. The mobile robot sets the upper limb section to a posture roughly extending in a horizontal direction orthogonal to the orthogonal rotation axis of the trolley-side arm adjustment section when performing an operation on the object. The horizontal plane direction in which the upper limb section extends can be changed by rotating the first rotation axis. The mobile robot sets the upper limb section to a posture roughly extending in a traveling direction when traveling. At this time, the orthogonal rotation axis of the trolley-side arm adjustment section becomes a horizontal direction almost perpendicular to the traveling direction.

[0005] In the mobile robot, it is necessary to suppress a fall due to an inertial force generated when accelerating travel, decelerating travel, or turning travel is performed. For a fall due to an inertial force generated when accelerating travel or decelerating travel is performed, the arm section can be set to a forward inclination posture or a backward inclination posture by rotating the joint having the orthogonal rotation axis of the trolley-side arm adjustment section. In order to suppress a fall due to an inertial force generated when turning travel is performed, it is necessary to move the center of gravity position of the arm section in a direction to a turning center as a right direction or a left direction with respect to the traveling direction. If a rotation axis parallel to the traveling direction is located at a position of the arm section close to the trolley, the necessary center of gravity movement is formed by inclining the arm section above the rotation axis in the right direction or the left direction with respect to the traveling direction, but the arm section having the basic structure assumed herein cannot incline almost the entire arm section in the right direction or the left direction with respect to the traveling direction because the trolley-side arm adjustment section does not have a rotation axis parallel to the traveling direction.

[0006] The purpose of this disclosure is to suppress falls during turning in a mobile robot with the following structure: the mobile robot has a trolley section and an arm mounted on the trolley section; the arm has: a first joint connected to the trolley section and having a first rotation axis in the vertical direction; a trolley side arm adjustment section, the lower end of which is connected to the first joint; and an upper limb section extending from the upper end of the trolley side arm adjustment section to an end effector; the trolley side arm adjustment section has one or more joints, the one joint having an orthogonal rotation axis orthogonal to the first rotation axis, and the multiple joints each having multiple orthogonal rotation axes orthogonal to and parallel to the first rotation axis.

[0007] Solution for solving the problem

[0008] A mobile robot according to one embodiment of this disclosure comprises: a trolley section; a movement mechanism for turning the trolley section; an arm section including: a first joint connected to the trolley section and having a first vertical rotation axis; a trolley side arm adjustment section having a first end and a second end, the first end being connected to the first joint; a middle arm adjustment section having a third end and a fourth end, the third end being connected to the second end; and a front end arm region connected to the fourth end; and a control section for controlling the movement mechanism and the arm section, wherein the trolley side arm adjustment section includes one or more joints, the one joint having one orthogonal joint orthogonal to the first rotation axis. The rotating axis, the plurality of joints each having a plurality of orthogonal rotating axes orthogonal to and parallel to the first rotating axis, the intermediate arm adjustment part including an intermediate joint, the intermediate joint causing the center of gravity of the front end side arm region to move in an out-of-plane direction toward a reference plane that serves as a plane through which the first rotating axis passes and is perpendicular to the one or more orthogonal rotating axes, the control part controlling the first joint to make the reference plane parallel to the travel direction of the trolley when the trolley part is turning, and controlling the intermediate joint to move the center of gravity of the front end side arm region in a direction having a directional component that is biased toward the turning center than the center of gravity position before the turn begins.

[0009] Invention Effects

[0010] According to this disclosure, a mobile robot with the following structure can suppress falls during turning, the mobile robot having a trolley portion and an arm mounted on the trolley portion, the arm having: a first joint connected to the trolley portion and having a first rotation axis in the vertical direction; a trolley side arm adjustment portion, the lower end of which is connected to the first joint; and an upper limb portion extending from the upper end of the trolley side arm adjustment portion to an end effector, the trolley side arm adjustment portion having one or more joints, the one joint having an orthogonal rotation axis orthogonal to the first rotation axis, and the multiple joints each having multiple orthogonal rotation axes orthogonal to the first rotation axis and parallel to each other. Attached Figure Description

[0011] Figure 1 This is a perspective view illustrating a mobile robot according to an embodiment.

[0012] Figure 2 This is a diagram illustrating the configuration of the control unit of a mobile robot according to an embodiment.

[0013] Figure 3A This is an explanatory diagram showing the movement of the joints of a mobile robot according to an embodiment.

[0014] Figure 3B This is an explanatory diagram showing the movement of the joints of a mobile robot according to an embodiment.

[0015] Figure 3C This is an explanatory diagram showing the movement of the joints of a mobile robot according to an embodiment.

[0016] Figure 3D This is an explanatory diagram showing the representation of joints and links when conforming to JIS standards.

[0017] Figure 4 This is a side view showing a representative pose of the mobile robot according to an embodiment.

[0018] Figure 5 This is a top view showing a representative pose of the mobile robot according to an embodiment.

[0019] Figure 6 This is a rear view of the zero-torque point in a representative posture of the mobile robot illustrating an embodiment.

[0020] Figure 7 This is a top view showing the mobile robot making a turning motion according to the embodiment.

[0021] Figure 8A This is a coordinate graph showing the time-varying rotation angle of the first joint of the mobile robot in the embodiment when it turns.

[0022] Figure 8B This is a coordinate graph showing the time-varying rotation angle of the second joint of the mobile robot in the embodiment when it turns.

[0023] Figure 8C This is a coordinate graph showing the time-varying rotation angle of the third joint of the mobile robot in the embodiment when it turns.

[0024] Figure 8D This is a coordinate graph showing the time-varying rotation angle of the fourth joint of the mobile robot in the embodiment when it turns.

[0025] Figure 8EThis is a coordinate graph showing the time-varying rotation angle of the fifth joint of the mobile robot in the embodiment when it turns.

[0026] Figure 8F This is a coordinate graph showing the time-varying rotation angle of the sixth joint of the mobile robot in the embodiment when it turns.

[0027] Figure 8G This is a coordinate graph showing the time-varying rotation angle of the seventh joint of the mobile robot in the embodiment when it turns.

[0028] Figure 8H This is a coordinate graph showing the time-varying rotation angle of the eighth joint of the mobile robot in the embodiment when it turns. Detailed Implementation

[0029] Hereinafter, an example of an embodiment of the present disclosure will be described with reference to the accompanying drawings. Furthermore, in the various drawings, the same or substantially equivalent elements, components, and parts are given the same reference numerals. Additionally, the dimensions and scales of the drawings are exaggerated for ease of explanation and sometimes differ from the actual scales.

[0030] like Figure 1 As shown, the mobile robot 26 according to this embodiment has a trolley section 22 and an arm section 28. The arm section 28, as an example, has 8 degrees of freedom.

[0031] exist Figure 1 In the example shown, the trolley section 22 is approximately rectangular. Hereinafter, the coordinate system for the trolley section 22 will be defined with X-axis, Y-axis, and Z-axis. The X-axis represents the front-to-back direction of the trolley section 22, the Y-axis represents the left-to-right direction, and the Z-axis represents the height direction. This left-to-right direction is also the width direction of the trolley section 22. Furthermore, the following explanation will assume that the height direction of the trolley section 22 is aligned with the vertical direction.

[0032] A moving mechanism 24 and a control unit 70 are provided in the trolley section 22. The control unit 70 controls the movement of the moving mechanism 24 and the arm section 28. The moving mechanism 24 has two drive wheels 24A, two driven wheels 24B, and two rotary drive sources (motors, not shown) that independently drive the two drive wheels 24A. The two drive wheels 24A are separated from each other in the left-right direction in the trolley section 22, and the two driven wheels 24B are also separated from each other in the left-right direction in the trolley section 22. The drive wheels 24A are positioned opposite each other at the rear of the vehicle, and the driven wheels 24B are positioned opposite each other at the front of the vehicle. These drive wheels 24A and driven wheels 24B support the mobile robot 26. Sometimes the drive wheels 24A and driven wheels 24B are collectively referred to as wheels.

[0033] like Figure 4 andFigure 6 As shown, drive wheel 24A and driven wheel 24B are connected to the ground LF, thereby supporting the mobile robot 26. The quadrilateral connecting the four points of drive wheel 24A and driven wheel 24B is the support area SA.

[0034] The drive wheels 24A are driven by a rotary drive source (not shown). For example, by rotating the two drive wheels 24A at a fixed speed, the trolley section 22 can move linearly. Furthermore, by making the rotational speeds of the two drive wheels 24A different on the left and right (differential rotation), the trolley section 22 can turn. In contrast, the driven wheel 24B can rotate freely without being driven by a rotary drive source. Moreover, the direction of the rotation axis of the driven wheel 24B can freely change in the horizontal plane. That is, the driven wheel 24B is a swivel caster (turning caster).

[0035] The arm 28 has 8 joints (first joint 31, second joint 32, third joint 33, fourth joint 34, fifth joint 35, sixth joint 36, seventh joint 37 and eighth joint 38), 3 links (first link 41, second link 42 and third link 43) and hand 50.

[0036] The first joint 31 has a first rotation axis J1 in a specific direction relative to the trolley section 22. In this embodiment, the specific direction is the normal direction relative to the upper surface 22A of the trolley section 22. Furthermore, in the illustrated example, the upper surface 22A of the trolley section 22 is parallel to the ground LF of the mobile robot 26. Therefore, the normal direction relative to the upper surface 22A of the trolley section 22 is also the normal direction relative to the ground LF. When the ground LF is horizontal, the direction of the first rotation axis J1 is vertical.

[0037] The second joint 32 is connected to the first joint 31 without any other joints intervening therein. The second joint 32 has a second rotation axis J2 in a direction orthogonal to the first rotation axis J1.

[0038] One end 41A of the first link 41 is connected to the second joint 32. The first link 41 has a length from one end 41A in a direction perpendicular to the second rotation axis J2.

[0039] The third joint 33 is located at the other end 41B of the first link 41. The third joint 33 has a third rotation axis J3 that is parallel to the second rotation axis J2.

[0040] One end 42A of the second link 42 is connected to the third joint 33. The second link 42 has a length from one end 42A in a direction perpendicular to the third rotation axis J3.

[0041] The fourth joint 34 is connected to the other end 42B of the second link 42. The fourth joint 34 has a fourth rotation axis J4 parallel to the third rotation axis J3.

[0042] like Figure 4 As shown, in the arm section 28, the trolley side arm adjustment section 28A includes a second joint 32, a first connecting rod 41, a third joint 33, a second connecting rod 42, and a fourth joint 34. The second joint 32 is the first end portion 28A1 of the trolley side arm adjustment section 28A, connected to the first joint 31. The fourth joint 34 is the second end portion 28A2 of the trolley side arm adjustment section 28A. The second rotation axis J2, the third rotation axis J3, and the fourth rotation axis J4 are orthogonal to the first rotation axis J1 when viewed from the Z-axis direction, and are examples of orthogonal rotation axes. The number of joints with orthogonal rotation axes orthogonal to the first rotation axis J1 included in the trolley side arm adjustment section 28A is not limited to 3, and can also be 1, 2, or 4 or more.

[0043] The fifth joint 35 is connected to the fourth joint 34, namely the second end 28A2 of the trolley side arm adjustment part 28A. The fifth joint 35 has a fifth rotation axis J5 in a direction orthogonal to the fourth rotation axis J4.

[0044] The sixth joint 36 is connected to the fifth joint 35. The sixth joint 36 has a sixth rotation axis J6 orthogonal to the fifth rotation axis J5 and is connected to the fifth joint 35. A connecting rod of a certain length may be located between the fourth joint 34 and the fifth joint 35. A connecting rod of a certain length may also be located between the fifth joint 35 and the sixth joint 36. That is, the fifth joint 35 and the sixth joint 36 are included in the intermediate arm adjustment part 28B, and the sixth joint 36 is located on the side opposite to the trolley side arm adjustment part 28A compared to the fifth joint 35.

[0045] like Figure 4 As shown, in arm 28, the intermediate arm adjustment part 28B is the portion that includes a fifth joint 35 and a sixth joint 36. The fifth joint 35 is the third end 28B3 of the intermediate arm adjustment part 28B, which is connected to the second end 28A2 of the trolley side arm adjustment part 28A. The sixth joint 36 is the fourth end 28B4 of the intermediate arm adjustment part 28B.

[0046] One end of the third link 43 is connected to the fourth end 28B4 of the intermediate arm adjustment section 28B, namely the sixth joint 36. The seventh joint 37, which has a seventh rotation axis J7, is connected to the other end of the third link 43. In the illustrated example, the seventh rotation axis J7 is parallel to the sixth rotation axis J6.

[0047] The eighth joint 38 has an eighth rotation axis J8 orthogonal to the seventh rotation axis J7 and is connected to the seventh joint 37. The seventh joint 37 and the eighth joint 38 are joints equivalent to the wrist. Although having joints equivalent to the wrist is not necessary, from the viewpoint of object operation, it is preferable to have two joints with mutually orthogonal rotation axes. The directions of the rotation axes of the two joints may also be different from the directions of the seventh rotation axis J7 and the eighth rotation axis J8.

[0048] Hand 50 is connected to the eighth joint 38. Hand 50 is an element that performs a prescribed operation or processing on an object, and is an example of an end effector. The specific structure of hand 50 is not limited if it can perform such a prescribed operation or processing on an object. For example, hand 50 may be configured to hold an object.

[0049] like Figure 4 As shown, in the arm 28, the front side arm region 28C is the part that includes the third link 43, the seventh joint 37, the eighth joint 38, and the hand 50.

[0050] The arm 28 is equipped with a camera device 60. The camera device 60 is located near the fourth joint 34. The camera device 60 can be of the type that captures still images or moving images.

[0051] exist Figure 2 The block diagram shows the hardware configuration of the control unit 70 that controls the movements of the mobile robot 26.

[0052] The control unit 70 includes a computer 140. The computer 140 includes a processor 142, a memory 144, a storage device 146, an input device 148, an output device 150, a storage medium reading device 152, and a communication I / F (Interface) 154. These components are communicatively connected to each other via a bus 156.

[0053] The storage device 146 stores a control program 158 for controlling the mobile robot 26. The processor 142 can execute various programs or control various elements. Specifically, the processor 142 reads the program from the storage device 146 and uses the memory 144 as a working area to execute the program. That is, the processor 142 performs control of various elements and various calculations based on the program stored in the storage device 146.

[0054] The memory 144 can temporarily store programs and various data as a working area.

[0055] Storage device 146 is, for example, ROM (Read Only Memory), HDD (Hard Disc Drive), and SSD (Solid State Drive), which stores various programs and data. These programs include not only the aforementioned control programs and other application programs, but also the operating system.

[0056] Input device 148 is a device for performing various inputs to computer 140. In addition to operation switches or buttons, input device 148 may also include pointing devices such as a keyboard or mouse for personal computers.

[0057] Output device 150 is a device for outputting various information from computer 140, such as a monitor or indicator light, speaker, etc. A touch panel display can also be used as output device 150, in which case the touch panel display also functions as input device 148.

[0058] The input device 148 and the output device 150 can also be detached when the mobile robot 26 is used. Alternatively, the input device 148 and the output device 150 can be omitted, and information such as motion commands for the mobile robot 26 can be input and information such as the motion status of the mobile robot 26 can be output via wireless communication through the communication I / F 154.

[0059] Storage medium reading device 152 is a device for reading data stored in various storage media and writing data to storage media. Examples of storage media include CD (Compact Disc)-ROM, DVD (Digital Versatile Disc)-ROM, Blu-ray disc, and USB (Universal Serial Bus) memory.

[0060] The Communication I / F154 is an interface used for communicating with other machines. For communication, standards such as Ethernet (registered trademark) and FDDI (Fiber Distributed Data Interface) can be used.

[0061] The aforementioned joints, hand 50, and drive wheel 24A are controlled by control unit 70. Specifically, for example, each joint rotates around its respective axis of rotation under the control of control unit 70 via a drive source (not shown). Similarly, hand 50 is also controlled by control unit 70 via a drive source (not shown) to perform a prescribed operation or processing on the object. Drive wheel 24A rotates under the control of control unit 70 via a rotation drive source (not shown).

[0062] The following, such as Figure 5 As shown, the reference plane SL is defined as a plane through which the first rotation axis J1 passes and perpendicular to the second rotation axis J2 (with the second rotation axis J2 as the normal). The forward, backward, and left-right directions of the mobile robot 26 are defined as follows.

[0063] Forward direction: along the X-axis defined with reference to the trolley section 22 and from the drive wheel 24A toward the driven wheel 24B.

[0064] Rear direction: the direction opposite to the forward direction

[0065] Left and right directions: directions that form a 90-degree angle with the forward direction and the vertical direction (left direction is the direction to the left of the forward direction).

[0066] In the mobile robot 26 of this embodiment, by rotating the fifth joint 35 or the sixth joint 36, the center of gravity position GP2 of the front end arm region 28C can be adjusted (see reference). Figure 4 and Figure 5 It moves outward from the reference plane SL. Thus, the joint that has the function of moving the center of gravity position GP2 of the front end side arm region 28C outward from the reference plane SL is an example of the "intermediate joint" of the disclosed technology.

[0067] Next, the operation and function of the mobile robot 26 in this embodiment will be explained. In the accompanying drawings illustrating the operation of the mobile robot 26, the following diagrams will be used... Figures 3A-3C The symbols shown. Figures 3A-3C The examples shown are all intended to represent various joints and links, with joint 30 and link 40 illustrated. Furthermore, each symbol indicates that link 40 rotates about joint 30 in the direction of arrow R1.

[0068] Figure 3D When following the JIS standard Figure 3C The corresponding descriptions of joint 30 and link 40. For example... Figure 3D As shown, in the JIS standard, the line segment of the connecting rod 40, extending in a direction orthogonal to the rotation axis of the joint 30, is described by connecting it to a shorter line segment representing the rotation axis via a broken line. This is simplified to... Figure 3C The shape of the graphic is such that the line segment of the connecting rod 40 is connected to the joint 30.

[0069] exist Figure 4 and Figure 5 In China, use Figures 3A-3C The diagrams of the joints and links shown depict the mobile robot 26. Figure 4 and Figure 5The diagram accurately represents the connection sequence of each joint and link, the direction of the rotation axis of each joint, and the orientation of each link. However, the three-dimensional positions of each joint and link may not be accurately represented. For example, refer to... Figure 1 It can be seen that connecting rod 41 and connecting rod 42 are separated in the Y direction and do not exist in the same plane, but... Figure 5 The diagram shows links 41 and 42 appearing to lie on the same plane. Furthermore, since the two joints are connected without the line segments representing the links being interposed, the three-dimensional relative arrangement of the two joints is not determined. For example, Figure 4 The three-dimensional configuration of the fourth joint 34 and the fifth joint 35 can be such that the fifth joint 35 is located in the X direction relative to the fourth joint 34, the fifth joint 35 is located in the Y direction relative to the fourth joint 34, or the fifth joint 35 is located in the Z direction relative to the fourth joint 34. Regardless of the configuration, the direction of the rotation axis J5 of the fifth joint 35 will rotate in the XZ plane along with the rotation of the fourth joint 34, and this remains unchanged.

[0070] In the mobile robot 26 of this embodiment, Figure 4 and Figure 5 The pose shown is designated as the representative pose. This representative pose has the following characteristics.

[0071] (1) The second rotation axis J2, the third rotation axis J3 and the fourth rotation axis J4 are parallel to the Y axis.

[0072] (2) Relative to the second rotation axis J2, the third rotation axis J3 is located behind in the X-axis direction, and the front end arm region 28C is located in front. The center of gravity GP1 of the mobile robot 26 is located in front of the top view center of the trolley section 22 (on the first rotation axis J1). (The representative posture can also be defined as the state in which the center of gravity GP1 of the mobile robot 26 is located at the top view center of the trolley section 22 (on the first rotation axis J1), or in a state that is located behind the top view center (on the first rotation axis J1).)

[0073] (3) The fifth rotation axis J5 is parallel to the X-axis.

[0074] (4) The center of gravity GP2 of the front side arm region 28C is located below the fifth rotation axis J5 (separated from the fifth rotation axis J5).

[0075] like Figure 6As shown, at the center of gravity GP1 of the mobile robot 26, there are forces of gravity F1 and inertial force F2. Inertial force F2 is the resultant force of the inertial force accompanying the mobile robot 26's forward and backward acceleration, the centrifugal force accompanying turning, and the inertial force accompanying the movement of the arm 28 caused by the driving of the first joint 31 to the eighth joint 38. The point where the direction of the resultant force F3 of gravity F1 and inertial force F2 intersects the ground LF is called the zero-moment point ZMP. When the inertial force F2 increases and the zero-moment point ZMP reaches the end of the support area SA, the mobile robot 26 begins to fall because any one of its wheels separates from the ground LF.

[0076] exist Figure 7 The diagram shows the movement trajectory TL of the center of the trolley section 22 when the mobile robot 26 is turning. In this example, the position of the first rotation axis J1 coincides with the position of the center of the trolley section 22, but the position of the first rotation axis J1 can also be located offset from the center of the trolley section 22. Figures 8A-8H In this paper, the changes in the rotational positions (measured values) of each rotation axis from the first rotation axis J1 to the eighth rotation axis J8 are shown as a function of time when each joint is controlled in such a way that the position of the zero torque point ZMP does not reach the end of the support area SA and the posture distance of the arm 28 represents a smaller error in posture. Here, the range of time can be divided as follows.

[0077] At time T1: Proceed in a straight line From time T1 to T2: Perform turning while gradually reducing the turning radius. From time T2 to T3: drive with a fixed turning radius. From time T3 to T4: Perform turning while gradually increasing the turning radius. Starting from time T4: Straight-line driving Regardless of the time frame, the forward velocity component remains constant.

[0078] In the mobile robot 26 of this embodiment, when turning, the first joint 31 is controlled so that the reference plane SL is parallel to the travel direction of the trolley section 22. As shown in the diagram of the rotation angle of the first joint 31... Figure 8AAs shown, the rotation angle of the first joint 31 is maintained at almost 0 degrees. This 0-degree angle is defined as the reference plane being parallel to the X-axis direction, i.e., the travel direction of the trolley section 22. If the angle between the reference plane SL and the travel direction of the trolley section 22 is within 10 degrees, the reference plane SL and the travel direction of the trolley section 22 can be considered substantially parallel. During turning, the control unit 70 controls the fifth joint 35 so that the center of gravity position GP2 of the front side arm region 28C moves in a direction having a component that is closer to the center of gravity of the turning point than the center of gravity position GP2 before the turn begins. This example of rotating the fifth joint 35 is an example of making the fifth joint 35 function as an intermediate joint in the disclosed technology.

[0079] The statement that "the control unit 70 controls the joints to bring the mobile robot 26 into a certain state when turning" (e.g., "when turning, the first joint 31 is controlled so that the reference plane SL is parallel to the travel direction of the trolley unit 22") does not necessarily mean rule-based control such as controlling the joints to a predetermined angle corresponding to the condition of turning. This statement includes calculating the angles that each joint of the arm 28 should take at each moment in order to travel along the indicated track without falling, and controlling the joints as a result, as stated in this statement. Figures 8A-8H The angle changes of each joint are calculated as a result, but the curves of these angle changes are not pre-programmed into the program.

[0080] The rotation angle of the fifth joint 35 is shown. Figure 8E The diagram shows that during cornering, the fifth joint 35 rotates significantly from the rotation angle before the turn begins. Figure 8E In the positive direction, the rotation angle is the angle at which the front side arm area 28C moves to the left of the turning center when representing the posture.

[0081] like Figure 8E As shown, from time T1 when the turn begins to time T2, the rotation angle of the fifth joint 35 gradually increases. From time T2 to time T3, the rotation angle of the fifth joint 35 remains approximately constant. Then, from time T3 to time T4, that is, at the end of the turn, the rotation angle of the fifth joint 35 gradually decreases.

[0082] like Figure 7 As shown, during the turning process of the mobile robot 26, an inertial force F2, including centrifugal force, acts in the opposite direction to the turning center RC. When the resultant force F3 of gravity F1 and inertial force F2 acts on the center of gravity of the arm 28, the zero-moment point ZMP moves in the opposite direction to the turning center RC. As a result, when the zero-moment point ZMP reaches the end of the support area SA, the mobile robot 26 begins to fall.

[0083] However, in the mobile robot 26 of this embodiment, since the center of gravity GP2 of the front arm region 28C is moved towards the turning center RC, the center of gravity GP1 of the entire mobile robot 26 also moves towards the turning center RC. Therefore, it is possible to suppress the zero torque point ZMP from approaching the end of the support region SA.

[0084] Furthermore, from the viewpoint of moving the center of gravity GP2 of the front side arm region 28C towards the turning center RC, the control unit 70 does not need to specifically control the rotation of the joints other than the fifth joint 35. In fact, in Figure 8, the rotation angles of the joints other than the fifth joint 35 are small. However, other joints can be rotated during turning without hindering fall prevention.

[0085] In order to move the center of gravity GP2 of the front side arm region 28C in the left-right direction by rotating the fifth joint 35, the center of gravity GP2 of the front side arm region 28C needs to be located at a position separate from the extension line of the fifth rotation axis J5. In the representative posture (where "separated from the extension line of the rotation axis" is also expressed as "separated from the rotation axis"), the center of gravity GP2 of the front side arm region 28C is not located on the extension line of the fifth rotation axis J5 but is located below it. In this embodiment, the sixth joint 36 is rotated such that the third link 43 forms a large angle (e.g., more than 30 degrees) with the fifth rotation axis J5, so that the center of gravity GP2 of the front side arm region 28C can be set at a position separate from the extension line of the fifth rotation axis J5. In order to move the center of gravity GP2 of the front side arm region 28C in the left-right direction by rotating the fifth joint 35, the fifth rotation axis J5 does not necessarily have to be horizontal; for example, the fifth rotation axis J5 can also be set to an angle other than horizontal by rotating the fourth joint 34.

[0086] In the disclosed technology, the state in which the center of gravity GP2 of the front side arm region 28C is not located on the extension line of the fifth rotation axis J5 can also be achieved as a structure of the arm 28 without relying on the rotation of the sixth joint 36. For example, it is also possible to omit the sixth joint 36 and achieve this by having a connecting rod structure that is forward of the fifth joint 35 and extends in a direction that forms an angle with the fifth rotation axis J5.

[0087] The above is an example of the fifth joint 35 functioning as an "intermediate joint" in the disclosed technology, but it can also be controlled to make the sixth joint 36 function as an "intermediate joint" in the disclosed technology instead. That is, when the mobile robot 26 is turning, and the center of gravity position GP2 of the front side arm region 28C moves towards the turning center RC, the control unit 70 rotates the sixth joint 36. By moving the center of gravity position GP2 of the front side arm region 28C towards the turning center RC in a direction that is more biased than the center of gravity position GP2 before the turn begins, the fall of the mobile robot 26 can be prevented.

[0088] In this case, when the direction of the sixth rotation axis J6 is orthogonal to the fourth rotation axis J4 (e.g., vertical), the effect of moving the center of gravity GP2 of the front side arm region 28C towards the turning center RC by rotating the sixth joint 36 is enhanced. Conversely, if the direction of the sixth rotation axis J6 is parallel to the fourth rotation axis J4 (horizontal), even if the sixth joint 36 is rotated, there will be no movement of the center of gravity GP2 of the front side arm region 28C towards the turning center RC. In order to move the center of gravity GP2 of the front side arm region 28C to the left or right by rotating the sixth joint 36, the direction of the sixth rotation axis J6 needs to be a direction with a component orthogonal to the fourth rotation axis J4 (the "orthogonal axis" of the disclosed technology). When the sixth joint 36 functions as an "intermediate joint," the fifth joint 35 is controlled so that the direction of the sixth rotation axis J6 becomes a direction with a component orthogonal to the "orthogonal axis." In order to move the center of gravity GP2 of the front side arm region 28C to the left and right by rotating the sixth joint 36, the center of gravity GP2 of the front side arm region 28C needs to be located at a position separate from the extension line of the sixth rotation axis J6, which is the same as when the fifth joint 35 functions as an "intermediate joint".

[0089] By combining the rotation of the fifth joint 35 and the sixth joint 36, the center of gravity GP2 of the front side arm region 28C can also be moved towards the turning center RC. In this case, both the fifth joint 35 and the sixth joint 36 function as "intermediate joints". As another embodiment, it is also possible to have a configuration without the sixth joint 36 and with the third link 43 perpendicularly connected to the fifth joint 35 along the fifth rotation axis J5.

[0090] The left-right movement of the center of gravity GP1 of the mobile robot 26 can also be achieved by rotating the first joint 31. Compared to rotating the fifth joint 35 or the sixth joint 36 to move the center of gravity, this method can suppress falls with less movement and less energy. In addition, the changes in the camera direction of the camera device 60 will also be reduced.

[0091] The following are notes relating to this disclosure.

[0092] (Note 1)

[0093] A mobile robot (26) has the following features: Trolley section (22); The moving mechanism (24) causes the trolley section (22) to turn; The arm (28) includes: a first joint (31) connected to the trolley portion (22) and having a first vertical rotation axis (J1); a trolley side arm adjustment portion (28A) having a first end (28A1) and a second end (28A2), the first end (28A1) being connected to the first joint (31); an intermediate arm adjustment portion (28B) having a third end (28B3) and a fourth end (28B4), the third end (28B3) being connected to the second end (28A2); and a front end arm region (28C) connected to the fourth end (28B4); and The control unit (70) controls the moving mechanism (24) and the arm (28). The trolley side arm adjustment part (28A) includes one or more joints (32, 33, 34). The one joint has one orthogonal rotation axis orthogonal to the first rotation axis (J1), and the multiple joints (32, 33, 34) each have multiple orthogonal rotation axes (J2, J3, J4) orthogonal to the first rotation axis and parallel to each other. The intermediate arm adjustment part (28B) includes an intermediate joint that moves the center of gravity (GP2) of the front end side arm region (28C) in an out-of-plane direction toward a reference plane (SL) that serves as a plane through which the first rotation axis (J1) passes and is perpendicular to the one or more orthogonal rotation axes (J2, J3, J4). The control unit (70) When the trolley section (22) is turning, the first joint (31) is controlled so that the reference plane (SL) is parallel to the direction of travel of the trolley section (22), and the intermediate joint is controlled so that the center of gravity (GP2) of the front side arm area (28C) moves in a direction having a component that is closer to the turning center (RC) than the center of gravity before the turn begins.

[0094] (Note 2)

[0095] According to Appendix 1, the mobile robot (26) wherein, The intermediate joint is a fifth joint (35) having a fifth rotation axis (J5) orthogonal to the orthogonal rotation axes (J2, J3, J4). When the trolley unit (22) is turning, the control unit (70) controls the fifth joint (35) so that the center of gravity (GP2) of the front side arm region (28C) is located at a position separated from the fifth rotation axis (J5), and the center of gravity (GP2) of the front side arm region (28C) moves in a direction having a directional component toward the turning center (RC).

[0096] (Note 3)

[0097] According to Appendix 1, the mobile robot (26) wherein, The intermediate arm adjustment section (28B) includes: a fifth joint (35) having a fifth rotation axis (J5) orthogonal to the orthogonal rotation axes (J2, J3, J4); and a sixth joint (36) having a sixth rotation axis (J6) orthogonal to the fifth rotation axis (J5), located on the side opposite to the trolley side arm adjustment section than the fifth joint (35). The intermediate joint is the sixth joint (36). When the trolley unit (22) is turning, the control unit (70) controls the fifth joint (35) so that the direction of the sixth rotation axis (J6) becomes a direction having a component of the direction orthogonal to the orthogonal rotation axes (J2, J3, J4), and controls the sixth joint (36) so that when the center of gravity position (GP2) of the front side arm region (28C) is located at a position separated from the sixth rotation axis (J6), the center of gravity position (GP2) of the front side arm region (28C) moves in a direction having a component of the direction toward the turning center (RC).

[0098] (Note 4)

[0099] The mobile robot (26) described according to any one of Appendix 1 to Appendix 3, wherein, The trolley side arm adjustment part (28A) includes: The second joint (32) is connected to the first joint (31) without any other joints in between, and has a second rotation axis (J2) in a direction orthogonal to the first rotation axis (J1). The first link (41), one end of which is connected to the second joint (32), has a length in a direction perpendicular to the second rotation axis (J2); The third joint (33) is located at the other end of the first connecting rod (41) and has a third rotating axis (J3) parallel to the second rotating axis (J2). The second link (42), one end of which is connected to the third joint (33), has a length in a direction perpendicular to the third rotation axis (J3); and The fourth joint (34) is located at the other end of the second link (42) and has a fourth rotation axis (J4) parallel to the third rotation axis (J3).

[0100] Furthermore, the entire disclosure of Japanese Patent Application No. 2023-170786, filed on September 29, 2023, is incorporated herein by reference.

[0101] All documents, patent applications and technical standards described in this specification are incorporated herein by reference to the same extent that each document, patent application and technical standard is specifically and individually described for reference.

Claims

1. A mobile robot, comprising: Trolley section; The moving mechanism enables the trolley to turn. The arm includes: a first joint connected to the trolley portion and having a first vertical rotation axis; a trolley side arm adjustment portion having a first end and a second end, the first end being connected to the first joint; a middle arm adjustment portion having a third end and a fourth end, the third end being connected to the second end; and a front end side arm region connected to the fourth end; and The control unit controls the moving mechanism and the arm. The trolley side arm adjustment unit includes one or more joints. The one joint has one orthogonal rotation axis orthogonal to the first rotation axis, and the multiple joints each have multiple orthogonal rotation axes orthogonal to the first rotation axis and parallel to each other. The intermediate arm adjustment section includes an intermediate joint that allows the center of gravity of the front end arm region to move in an out-of-plane direction toward a reference plane that serves as a plane through which the first rotation axis passes and is perpendicular to the one or more orthogonal rotation axes. The control unit When the trolley is turning, the first joint is controlled so that the reference plane is parallel to the direction of travel of the trolley, and the intermediate joint is controlled so that the center of gravity of the front side arm region moves in a direction having a component that is closer to the center of gravity of the turning center than the center of gravity before the turn begins.

2. The mobile robot according to claim 1, wherein, The intermediate joint is a fifth joint having a fifth rotation axis orthogonal to the orthogonal rotation axis. When the trolley is turning, the control unit controls the fifth joint so that, with the center of gravity of the front side arm region located at a position separate from the fifth rotation axis, the center of gravity of the front side arm region moves in a direction having a directional component toward the turning center.

3. The mobile robot according to claim 1, wherein, The intermediate arm adjustment part includes: The fifth joint has a fifth rotation axis orthogonal to the orthogonal rotation axis; as well as The sixth joint has a sixth rotation axis orthogonal to the fifth rotation axis, and is located on the side opposite to the trolley side arm adjustment part compared to the fifth joint. The intermediate joint is the sixth joint. When the trolley is turning, the control unit controls the fifth joint so that the direction of the sixth rotation axis becomes a direction with a component orthogonal to the orthogonal rotation axis, and controls the sixth joint so that when the center of gravity of the front side arm region is in a position separated from the sixth rotation axis, the center of gravity of the front side arm region moves in a direction with a component toward the turning center.

4. The mobile robot according to claim 1, wherein, The trolley side arm adjustment unit includes: The second joint is connected to the first joint without passing through other joints, and has a second rotation axis in a direction orthogonal to the first rotation axis; The first link, one end of which is connected to the second joint, has a length in a direction perpendicular to the second axis of rotation; The third joint is located at the other end of the first connecting rod and has a third rotation axis parallel to the second rotation axis; The second link, one end of which is connected to the third joint, has a length in a direction perpendicular to the third axis of rotation; and The fourth joint is located at the other end of the second link and has a fourth rotation axis parallel to the third rotation axis.

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